text:
Department of Civil and
Architectural Engineering,
Qatar University,
P.O. Box 2713,
Doha, Qatar
e-mail: email@example.com
Department of Civil and
Architectural Engineering,
Qatar University,
P.O. Box 2713,
Doha, Qatar
e-mail: email@example.com
Department of Civil and
Architectural Engineering,
Qatar University,
P.O. Box 2713,
Doha, Qatar
e-mail: firstname.lastname@example.com
Department of Civil Engineering,
University of Kentucky,
373 Raymond Building,
Lexington, KY 40506
e-mail: email@example.com
Professor of Structural Dynamics and
Control, Mathematics, and Physical Sciences
College of Engineering,
University of Exeter,
North Park Road,
Exeter EX4 4QF, UK
e-mail: email@example.com
1Corresponding author.
Manuscript received August 24, 2016; final manuscript received March 22, 2017; published online April 10, 2017. Assoc. Editor: Francois Barthelat.
With the use of lighter construction materials, more slender architectural designs, and open floor plans resulting in low damping, vibration serviceability has become a dominant design criterion for structural engineers worldwide. In principle, assessment of floor vibration serviceability requires a proper consideration of three key issues: excitation source, system, and receiver. Walking is usually the dominant human excitation for building floors. This paper provides a comprehensive review of a considerable number of references dealing with experimental measurement and mathematical modeling of dynamic forces induced by a single pedestrian. The historical development of walking force modeling—from single harmonic loads to extremely complex stochastic processes—is discussed. As a conclusion to this effort, it is suggested that less reliance should be made by the industry on the deterministic force models, since they have been shown to be overly conservative. Alternatively, due to the random nature of human walking, probabilistic force models seem to be more realistic, while more research is needed to achieve enough confidence to implement in design practice.
Excessive vibrations sometimes create significant problems for the occupants of various types of structures, including stadia [1], theaters [2], building floors [3,4], footbridges [5,6], and staircases [7]. These problems are naturally generated due to the implementation of lighter construction materials, more slender and aesthetic architectural designs, and open floor plans with few full-height nonstructural partitions, which results in low damping [8–10]. Therefore, vibration serviceability has become a dominant criterion in structural design over the last few years [11–14] and has been increasingly the focus of researchers worldwide. However, it should also be mentioned that floor vibration problems have been known about since olden times, which is evident from the following comment by Tredgold [15]:
Girders for long bearings should always be made as deep as the timber can be obtained; an inch or two taken from the height of a room is of little consequence compared with a ceiling disfigured with cracks, besides the inconvenience of not being able to move without shaking everything in the room.
Any structural vibration serviceability analysis may be broken down into three key constituents, as indicated in Fig. 1. These are the input (excitation source), the system (floor structure), and the output (vibration receiver) [16–20], which is either a human occupant or vibration-sensitive equipment. This paper focuses on the first aspect of the analysis, which is the dynamic loading. Human activities such as walking [21], jogging [22], jumping [23], and running [24] are common sources of dynamic excitations leading to vibration problems.
The two main parameters typically used to quantitatively describe vibration response are amplitude and frequency [25]. Receivers are often more sensitive to vibration at some frequencies than at others. If the amplitude, described either by peak or root-mean-square (RMS) value, exceeds a tolerance limit at the frequency of vibration, then vibration is considered to be excessive [11]. As a consequence, building occupants become annoyed and adverse comments may result. In a similar manner, floors may fail to accommodate vibration-sensitive equipment in medical and industrial facilities.
Despite the importance of vibration serviceability in structural design, human-induced excitation of floors remains relatively poorly understood, and there is a proliferation of contradictory dynamic load models [26]. In all likelihood, this is due to many uncertainties associated with human walking. These uncertainties make it challenging to reliably predict the load using computer modeling and simplified manual calculation approaches [27]. Despite the preceding vast research efforts in this area, these uncertainties still require further examination to enhance the reliability of the assessment of floor vibrations during the design stage.
For building floors, especially ones in quiet environments such as offices, walking is the most frequently occurring and often dominant type of human-induced excitation [17,28,29]. Therefore, this paper aims to provide the reader with a solid background on modeling the dynamic load induced on building floors by a single pedestrian, bearing in mind that the ground or the supporting structure is assumed to be rigid. In effect, excellent state-of-the-art reviews pertaining to vibration serviceability were published by Pavic and Reynolds [16,17] for building floors, Živanović et al. [20] for footbridges, and Jones et al. [1] for sports stadia. In addition, a significant research effort has been dedicated in Ref. [19] with the purpose of comprehending experimental and analytical studies related to the walking forces, with more concentration on the biomechanics of human walking. However, the original contribution of this paper can be outlined in the following points: (a) Considering the elapsed time and the large body of work carried out since the previous review papers, this effort comprises more recent research studies in the field of vibration serviceability in general and human walking force modeling in particular. Furthermore, the latest review article known to authors and specifically concerning floor vibration was published over a decade ago [16,17,26], with the exception of Ref. [30] that was only focused on the response of high-frequency floors; (b) this paper is designed to be more focused toward the direction of the vibration serviceability for building floors. Hence, the assumptions, considerations, and the discussions made in this paper are actually more relevant to the dynamics of building floors. For instance, even when including footbridge-related studies as in Ref. [20], only the "vertical forces" part was extracted for discussion in this review article owing to its applicability in the case of building floors.
At the outset, the human walking process will be explained along with the definition of its relevant key concepts. Then, discussions of studies related to experimental measurement of vertical walking forces will be presented. After that, the historical evolution of the force models proposed for human walking will be discussed, starting from the simplest which assumes the load to be harmonic and ending with the most complex stochastic models. Finally, a pertinent study is presented to compare different types of walking force models.
During walking, each foot passes through two phases during a single step: the swing phase and the stance (or contact) phase. The swing phase refers to the period when the foot is off the ground, while the stance phase refers to the period during which the foot contacts the floor. The stance phase starts when the heel strikes the ground and ends by the act of the foot toe-off [31].
Concurrently, the human body passes through two stages during the walking process: the double- and the single-support stage. The double-support stage occurs when both feet are in contact with the floor (i.e., one foot contacts the ground while the other foot is still in a contact) and comprises not more than 20% of the walking cycle [32]. It has been verified that as the walking speed increases, this stage comprises a smaller percentage of the walking time. Conversely, the human body is at the single-support stage when one foot is in contact, while the other one is off the ground [33]. In the case of running, which can be considered as an extreme form of walking in terms of speed, the human body passes regularly through a no-support stage during which both feet are off the ground [34].
A complete cycle consists of the human motion that occurs from the start of a step with one foot to the start of the next step with that same foot, as illustrated in Fig. 2, and explained through a series of consecutive events as follows [35–38]:
Two types of parameters are used to describe the walking routine: temporal (time) and spatial (distance or location) parameters [39].
Walking speed, cycle time, and pacing rate (walking frequency) are typically measured time parameters. Walking speed is the magnitude of horizontal velocity in the gait direction, usually expressed in meters per second. Pacing rate, also known as step frequency, is the number of steps in a specific duration, usually expressed in steps per minute or Hz. Cycle time represents the period of time during which a complete cycle occurs [37].
Commonly used spatial parameters are step length, step width, and stride length (or cycle length). Step length is defined as the distance measured during a single step between both heels in the direction of walking. Step width is the distance measured transversely between the two lines which describe the paths taken by the right and the left foot, where these lines pass through heel midpoints. Stride length is the distance measured along the gait direction between two consecutive contacts of the same foot. It also represents the total distance traveled during one cycle period [38].
Two types of randomness exist in human walking: intersubject and intrasubject variability [40]. Intersubject variability exists because different persons will have different key parameters which are directly related to the induced forces, such as subject weight, step frequency, walking speed, and so on [41]. Consequently, the resultant walking forces vary from person to person. However, intrasubject variability exists because an individual never repeats two identical steps in sequence; therefore, a person produces forces which are different at each footfall [42].
In general, a walking person causes dynamic forces which have components in three directions: (a) vertical, (b) horizontal–parallel, and (c) horizontal–transverse to the direction of movement [43]. In this paper, research studies considering mainly the vertical component will be the focus because:
Several researchers, starting with Harper [44] and followed by Galbraith and Barton [34], Blanchard et al. [45], Ohlsson [46], Andriacchi et al. [47], and Kerr [48], used force transducers to measure the dynamic forces resulting from individual footfalls. Their measurements indicate that the vertical force typically has two peaks and a trough as shown in Fig. 3.
In the figure, the vertical force is expressed as a percentage of the body weight, and the time is normalized with respect to the stance phase (see Fig. 2) duration. Once the heel strikes the floor, the dynamic force increases until it approaches a peak value of F1 at time, T1, which is at approximately 25–30% of the stance phase duration. After that, the dynamic force decreases until the midstance point, T2, at which both the heel and toe are in contact with the ground, while the opposite foot is in a swing phase. Subsequently, the heel rises and the vertical force increases until it reaches another peak, F3, at time, T3, near the end of the stance phase and heel strike of the other foot. Finally, the foot rises from the floor and the force decreases quickly to zero at the stance phase completion [19].
Single-step force measurements were followed by more advanced recordings of multiple step walking force waveforms. Blanchard et al. [45] developed the "gait machine," while Rainer et al. [49] employed a floor strip on which ground reaction forces were continuously measured during walking and other activities. More recently, Ebrahimpour et al. [50] utilized a short walkway that consisted of several individual force plates. In studies by these researchers, it was observed that the measured time histories were approximately periodic, with a typical cycle time equal to the reciprocal of the average step frequency.
Galbraith and Barton [34] investigated the effect of walking speed on the vertical force due to individual footfalls on a force plate. They reported a number of differences between the running and walking dynamic forces resulting from a single step. Essentially, the dynamic force graph induced by running had typically a single peak, dissimilar to the double-peaked shape recorded from walking. Moreover, two main factors were thought to influence the amplitude of the peak force: subject weight and pacing rate. It was observed, from the results of Galbraith and Barton [34], that increasing those factors leads to higher peak forces.
Assume that single-step forces are identical, combining single-step graphs in a successive manner resulted in artificial time histories for the forces excited by continuous walking and running, as shown in Fig. 4. A typical short period can be observed in the running time history, during which both feet are off the floor, and thus, no force is excited. On the other hand, through the continuous walking time, there is a frequent overlapping between the left and the right feet forces, which is noticed the moment both feet are on the floor.
Wheeler [51,52] conducted a wide-ranging study, which is recognized as a considerable step forward into the research in human-induced forces. The author organized the work of previous investigators and classified different categories of human moving, arranged from slow walking to running. Each of these categories had a single-step dynamic force that was unique in peak amplitude, shape, and stance period, as shown in Fig. 5. Furthermore, the same author stated that several parameters such as stride length, walking speed, contact time, peak force, and step frequency are related. For instance, for a constant stride length, the walking speed tends to increase as the step frequency rises. Moreover, increasing the step frequency results in shortening the contact time as well as boosting the peak force.
It should be highlighted that even though human-induced walking force is mainly focused on, running is sometimes mentioned in this paper since it is regarded as an extreme case of walking in terms of movement speed.
Section 3 has discussed research studies describing the measurement of the vertical dynamic forces induced by a walking pedestrian and some important relationships between measured force and walking parameters. The next step is to develop reliable mathematical representations of these forces, a process termed force modeling [53]. The resulting models can be used to predict vibration during the design phase.
Mathematical modeling of human-induced dynamic forces is challenging for a number of reasons. First, there is high variability of force waveform shapes [52] (e.g., the differences observed in Fig. 5) due to many parameters which have high inter- and intrasubject variability [54]. Moreover, the dynamic forces induced by a single person are narrowband random processes (as will be discussed later) that are not well understood and thus are difficult to accurately represent [55].
Nevertheless, force models have been presented by researchers within the past few decades based on reasonable assumptions, and some are employed in the widely used design guides. Two types of models have been proposed for human-induced walking excitation: time- and frequency-domain force models; the former is currently much more widely used.
Time-domain force models are subdivided into two main groups in the literature: deterministic and probabilistic. Deterministic models aim to generate a uniform force model for any individual without directly considering the natural variability between people [56]. However, the probabilistic model takes into account the fact that each individual has a unique set of parameters directly influencing the produced forces such as static weight, pacing rate, and so on, which is referred to as intersubject variability. This kind of unpredictability is described for each parameter via its probability density function, and thus considered in the force model by means of probability of occurrence [57].
In Secs. 4.1–4.3, the main types of force models are presented according to their progression through the history of research in this area, as illustrated in Fig. 6. Time-domain deterministic force models are discussed first because they are the oldest and the most common. This type of force model is presented from the simplest to the most advanced ones that are utilized in the current design guides. After that, frequency-domain representation of walking force is introduced, and some relevant research studies are discussed. Finally, some recent complex stochastic force models are explained.
With the consideration of deterministic force models, computing vibration responses is typically based on key assumptions such as perfectly periodic induced forces and linear elastic system [12]. The magnitude of human-induced vibration has been considered to depend significantly on the ratio of walking frequency of the pedestrian and lowest vertical natural frequency of the floor. Two types of floors are presented in the literature according to their natural frequency: low- and high-frequency floors [19]. Low-frequency floors are typically regarded as floors having at least one responsive natural frequency lower than 9–10 Hz, while the lowest natural frequency of high frequency floors is higher than 9–10 Hz. A large body of research related to modeling of walking forces has concluded that the dynamic response in the two cases can be considerably different.
Previous studies have demonstrated that in low-frequency floors, responses to successive heel strikes tend to build up leading to the state of (near-)resonance [58]. This phenomenon takes place when the natural frequency of the floor is close to the typical human walking pace (1.5–2.5 Hz) or an integer multiple of the walking frequency. On the other hand, high-frequency floors typically do not exhibit resonance under successive footfalls. As will be detailed later, the response of such floors resembles a series of impulse responses to each footstep.
So far, there is no deterministic walking force model that can be used for prediction of both low- and high-frequency floor responses. In all likelihood, this is due to the different response behavior assumed for each type. Therefore, researchers have developed different force models for each, which are discussed in Secs. 4.1.1 and 4.1.2.
Being assumed as periodic, the vertical dynamic force induced by a walking pedestrian Fp(t) can be expressed in the time domain by a summation of harmonic components (i.e., Fourier series), as per the following equation [56]:
Display Formula
where G is the individual's static weight (N), i is the order number of the harmonic, n is the number of all contributing harmonics, fp is the step frequency (Hz), ϕi is the phase shift of the ith harmonic (rad), and αi is the Fourier coefficient of the ith harmonic usually known as the dynamic load factor (DLF), and sometimes referred to as the dynamic coefficient.
Therefore, based on this equation and with the assumption of linearly elastic and proportionally damped structure, the vibration response of the floor is computed by the summation of responses to all contributing harmonics. Obtaining appropriate values of DLF (αi) for the contributing harmonics is the key to generate an accurate deterministic force model. Several researchers have used experimental studies to estimate DLFs over the years, resulting in the force models in the major design guides in use today.
One of the first deterministic force models was published by Blanchard et al. [45] who proposed a simple model for the load exerted on footbridges by a pedestrian. This model considered that resonance would occur in the first vibration mode due to the first harmonic of the dynamic load. Two main scenarios, depending on the footbridge's natural frequency, were considered as follows:
A few years later, Kajikawa (according to Yoneda [59]) developed an enhanced walking force model by considering the first harmonic DLF and including the "correction coefficient" illustrated in Fig. 7. The author introduced a direct relationship between the dynamic force and walking pace (step/s). Moreover, walking speed (m/s) was also included in his model as an output dependent on step frequency.
As a decent forward step, Bachmann and Ammann [43] reported the Fourier coefficient values for the first five harmonics of the walking force. Also, they indicated that the walking-induced load is strongly related to step frequency. The force components in all directions (vertical, midlateral, and longitudinal) were included in their effort. The authors suggested vertical force DLFs of 0.4 and 0.5 for the first harmonic DLF at frequencies of 2.0 and 2.4 Hz, respectively, with linear interpolation for the frequencies in between. Regarding the second and third harmonics, a DLF value of 0.1 was proposed if the step frequency is close to 2.0 Hz.
In 1988, Rainer et al. [49] added a significant contribution by including further types of human activities. The authors measured the continuous force waveform induced by walking, running, and jumping on an instrumented platform, and then Fourier transformed each waveform to a force spectrum with peaks that provide estimates of the DLFs. Like others, they confirmed the strong relation between the DLFs and the activity frequency. The authors included the first four harmonics of the activity in their proposed force models, while the DLFs were observed to decrease with higher order of harmonics. Interestingly, the dynamic forces reported for walking were found to be considerably higher than the ones suggested by previous researchers. According to Refs. [19,20], this study was not statistically rigorous because it included measurements from only three test individuals.
As a part of his Ph.D. thesis, Kerr [48] conducted one of the most comprehensive studies relevant to human-induced walking forces. He engaged a total number of 40 test subjects and requested that each perform a single footfall on a force plate. Different step frequencies were used by the test subjects, ranging from very low (1 Hz) to very high (3 Hz), a significantly larger range than that of typical step frequencies. Consequently, nearly 1000 single-step force measurements were collected, generating a very large database of walking forces.
Each footstep was repeatedly appended and summed to synthesize a waveform of a walking event, which was Fourier transformed to a spectrum to estimate the DLFs. For only the first harmonic, it was noticeable that the dynamic forces increase with step frequency. However, for the other harmonics, the DLF values were largely scattered and thus statistically described simply by mean values and standard deviations. Racic et al. [19] stated that the main shortcoming of this study was the incapability of its data to represent the intrasubject variability. The force model proposed by Kerr did not consider the fact that a single individual is improbable to produce two identical steps in sequence.
Subsequent to Kerr's effort, Young [60] as well as Willford et al. [61] took a valued step and conducted a wide-ranging study to develop a reliable guide for modeling walking forces. The authors assembled the data published from several researchers, as presented in Fig. 8, and performed statistical regression. As a result, they proposed mean and design values of DLF for the first four harmonics of a walking force.
The following set of equations was suggested by Young [60] for the design values (i.e., suitable for serviceability assessment) as a function of step frequency:
Display Formula
where f is the frequency of the relevant harmonic, which apparently equals an integer multiple of the pacing rate. As shown in Eq. (2), Young considered the pacing rate to range between 1 and 2.8 Hz, reasonably assuming that step frequencies out of this range are not likely to occur in reality. He stated that the recommended design values have 25% probability of exceedance [60], which makes him one of the earliest investigators to consider the probabilistic nature of human walking.
Table 1 presents the DLFs for vertical human-induced forces reported from several authors. The table is extracted from the Živanović et al. literature review about vibration serviceability of footbridges [20]. This table is a brief outline of the efforts mentioned earlier in this section.
The force modeling approaches previously discussed in this section were all based on experimental measurement of walking loads on rigid surfaces. It means that these models might not be accurate for simulating the response of flexible floors subjected to human-induced dynamic excitation. For instance, Baumann and Bachmann [63] reported that the magnitude of the walking load on stiff floors was approximately 10% more compared to the one measured on the flexible counterparts. Likewise, Pimentel [64] reported that walking forces measured on flexible footbridges were much lower than previously recorded ones on stiff surfaces.
Bocian et al. [65] stated that there is an inevitable shortcoming resulted from disregarding the human–structure dynamic interaction in the proposed force models. This shortcoming results from the scarcity of measurement techniques that are used to track the dynamic forces in the presence of structural motion. To address this problem, the same authors [65] proposed a biomechanically inspired inverted-pendulum force model that can represent the dynamic interaction between the pedestrian and the footbridge, which was proved to have a significant effect in the case of moving crowds.
Floors with no responsive natural frequency below 9–10 Hz (i.e., higher than four times the average walking frequency) are referred to as high-frequency floors. Figure 9 illustrates the difference between the response behavior in high- and low-frequency floors. Unlike the resonant behavior exhibited in the response of low-frequency counterparts, the response of high-frequency floors under footfall loads has a transient (impulsive) profile [30]. At first, a heel impact produces an initial peak response. Afterward, the floor oscillates at its natural frequency with a decaying rate associated with the damping ratio of the fundamental mode [66]. Likewise, as soon as the subsequent footfall strikes the floor, another impulse response is generated. Hence, the vibration responses of successive steps do not build up in the case of high-frequency floors due to structural damping decaying effect.
The literature on walking force modeling for high-frequency floors is limited when compared with low-frequency floors because most vibration serviceability problems are due to human discomfort on low-frequency floors. A main relevant study on high-frequency floor force models was conducted by Willford et al. [67]. The analytical force model introduced in this study was formulated based on the similarity between the transient response of high-frequency floors under walking forces and the response of single degree-of-freedom systems under a series of impulse forces. In order to generate this model, Willford et al. [67] simulated the responses of a large number of single degree-of-freedom (SDOF) systems, which had a unit modal mass as well as different natural frequencies, under continuous walking forces synthesized from Kerr's single-step measurements. For each simulation, the peak velocity of the SDOF system was computed and used to obtain a quantity called the effective impulse. Since each SDOF system has a unit modal mass, the effective impulse is numerically equal to the initial (i.e., peak) velocity.
The results of this study suggested that effective impulse increases as the walking frequency decreases, and it also decreases with higher natural frequencies of the floor. Based on statistical analysis of the results presented in Fig. 10, the following equation was developed for calculating the effective impulse Ieff, with N s units, on a high-frequency floor [67]:
Display Formula
where f is the walking frequency (in Hz) and fn is the floor's natural frequency (in Hz). Ieff computed according to this equation has a 25% probability of exceedance.
Being the most common approach to the mathematical representation of walking force, the reliability of deterministic force models has been extensively tested by investigators and structural engineers. It has been shown that deterministic modeling approaches are not very accurate or precise, often leading to overestimation of the floor vibration response [55], and less commonly leading to underestimation of the response [68]. In view of that, the following points were identified as possible weaknesses of deterministic force modeling:
Continuous walking forces can be alternatively represented in the frequency domain. The walking time history can be expressed in terms of the amplitudes obtained for the corresponding sine and cosine waves via Fourier transform decomposition [70,71]. Ohlsson [46] was one of the earliest to research frequency-domain representations of human-induced forces. By measuring a single footfall force and then repeating it, assuming perfect periodicity, Ohlsson created an artificial time history of a continuous walking force. He found that a single step holds most of its excitation energy in the frequency range between 0 and 6 Hz. Moreover, he considered the walking force as a transient signal resulting from a series of perfectly repeated footfalls, and accordingly determined the corresponding autospectral density (ASD). Since Ohlsson's study was concentrated on the behavior of high-frequency floors, he focused on the frequency content of the ASD in a relatively high-frequency range (6–50 Hz).
After that, Eriksson [72] conducted a more concentrated study aimed to investigate the continuous walking force in the frequency domain considering the case of low-frequency floors. Eriksson produced the ASD for the indirect measurements of walking forces, focusing on the frequency range (0–6 Hz). As can be observed from Fig. 11, the content of excitation energy at integer multiples of step frequency is smeared into the adjacent frequencies, producing what is known as leakage at each peak. Deeply rooted in digital signal processing, this leakage indicates that the human walking force is not perfectly periodic [70]. Therefore, the same author stated that human walking should be rather described as a random process [72].
It should be mentioned that the existence of such imperfections in walking periodicity was previously indicated by Rainer et al. [49] during their investigation of the dynamic load induced on footbridge by a walking pedestrian. The authors compared the measured values of response produced by pedestrians attempting to excite resonance with the analytical sinusoidal steady-state ones which were based on the first walking harmonic. Interestingly, the authors reported that the measured responses were approximately one-half of its analytically predicted peers, indicating the significance of the temporal imperfections in the walking force [49].
As a significant step forward, Brownjohn et al. [55] employed the spectral density approach for modeling continuous vertical walking forces on pedestrian structures. As shown in Fig. 12, the authors utilized a treadmill instrument to record the real walking forces in a continuous manner rather than artificially repeating a measured single footfall. Three test subjects were requested to walk at a self-selected pacing rate with different speeds ranging between 2.5 and 7.5 m/s. Consequently, each test subject produced a sequence of 1-min walking time histories along with the corresponding pacing rates and gait parameters. In spite of the small number of test subjects, the authors argued that their study aimed to focus on the effect of the intrasubject rather than the intersubject variability nature, which had been already studied in detail by other researchers.
After that, these records were compared with those produced by deterministic force models based on the assumption of perfect periodicity. Figure 13 shows the Fourier amplitudes, normalized with respect to body weight, for deterministic force modeling at a pacing rate of 1.91 Hz. The figure illustrates that the force function is estimated with its harmonic components using Eq. (1) [55]. On the other hand, Fig. 14 presents the Fourier amplitude spectrum for the real walking force signal recorded for the same subject weight and step frequency.
Comparing Figs. 13 and 14, it is observed that there is a leakage of excitation energy from the deterministic force case to the actually measured one, which appears to be more significant for higher harmonics. This indicates that modeling of walking force using the classical deterministic approach is overconservative and inaccurate. Alternatively, the authors proposed a frequency-domain modeling approach for both single individual and crowds, which was based on the ASD function to represent the walking imperfections, similar to the use of stochastic analysis in wind load modeling [55].
In another study, Sahnaci and Kasperski [73] stated that the imperfections in pedestrian walking pattern result in what is known as subharmonics, which are actually intermediate load amplitudes holding a relatively significant portion of excitation energy between the main harmonic frequency bands (0.5fw, 1.5fw, andsoon), similar to what is shown in Fig. 15. The authors suggested that the main reason of this phenomenon is the inevitable difference between left and right feet in terms of walking parameters, such as step length and pacing rate. Furthermore, based on studying a relevant example, they stated that the dynamic response predicted without taking these subharmonics into consideration deviates significantly from the actual one [73].
As mentioned before, the currently applied vibration serviceability assessment of floors is usually based on the assumption that a single person walks at a step frequency corresponding with a natural frequency of the structure [54]. This practice has been shown to significantly overestimate the floor dynamic responses due to neglecting the leakage associated with imperfect periodicity of human walking. Therefore, probabilistic modeling has been introduced in the literature as a more reliable approach to mathematical representation of human-induced forces. In this manner, human activity is considered to be rather a random or stochastic process with nondeterministic behavior (i.e., the next state is not predictable knowing the current state) [74].
Based on the probabilistic approach to force modeling, each person has a unique set of key parameters such as subject's weight, stride length, and step frequency, which is referred to as intersubject variability [75]. In order to achieve a reasonable statistical description of these parameters, a considerable number of measurements are first required [76]. These variables, which describe human-induced force, are then defined in the model via their probability density functions. Furthermore, it is also taken into account that a single pedestrian will never produce consecutively two identical steps (i.e., intrasubject variability). Hence, the walking force time histories recorded during repeated experiments for the same person will be different [77].
As a final result, instead of producing a single vibration response value, which allows only a pass/fail assessment, the vibration response can be expressed as a probability that it will not exceed a certain value. This would be more convenient since it provides more space for engineering judgment since vibration, in general, is considered to be a serviceability rather than a safety design issue [78].
Several researchers have worked to achieve a reliable statistical description of human pacing rate [54]. At first, Leonard [79] suggested a range of 1.7–2.3 Hz for normal speed walking frequency. After that, Matsumoto et al. [80] conducted a comprehensive study on a sample of 505 individuals walking at a self-selected speed. They concluded that step frequency typically followed a normal distribution with a mean value of 1.99 Hz and standard deviation of 0.173 Hz. Afterward, Kerr and Bishop [81] examined 40 individuals, resulting in a mean value of 1.9 Hz for walking frequency. More recently, Živanović et al. [69] investigated around 2000 pedestrians crossing a footbridge located in Montenegro. The aim of this study was to achieve probability density functions for various walking parameters such as pacing rate. Like the preceding researchers [79,81,82], the authors reported the normal distribution for pacing rate, but with a different mean value (1.87 Hz) and standard deviation (0.186 Hz). Also, Kasperski and Sahnaci [83], Pachi and Ji [84], as well as Kramer and Kebe [85] reported average pacing rates of 1.82, 1.8, and 2.2 Hz, respectively. Figure 16 shows the normal distribution function proposed by different authors for the step frequency of regular walking.
There is a notable difference between mean step frequencies from several studies in the literature. Zivanovic [86] explained such inconsistency by the variety of cultures. For instance, Wiseman stated that people in Singapore tend to walk faster than the citizens of the UK [87]. Therefore, Racic et al. [19] suggested that in order to perform a reliable statistical analysis of walking parameters, a random sample of people from different genders, nations, and cultures should be collected.
In addition, Pachi and Ji [84] have introduced the environment as a factor affecting not only the step frequency but also the walking speed. They studied about 200 walkers, of both genders, on two shopping floors and two footbridges. From statistical analysis of the nearly 800 measurements, they concluded that human pacing rate is usually higher in the case of shopping malls rather than footbridges. Even though the normal probability distribution was described for step frequency in both cases, the mean values of the shopping malls and footbridges were 2.0 and 1.8 Hz, respectively. Regarding the walking speed, a slightly higher value was reported in the case of shopping malls (1.4 m/s) compared with the footbridges (1.3 m/s) [84]. Also, the authors proposed a linear relation between walking velocity v (m/s) and step frequency f (Hz), which is expressed as follows:
Display Formula
where Ls is the step length, which has mean values of 0.75 m for males, 0.67 m for females, and 0.71 m in general.
Interestingly, via statistical analysis of the data collected by Pachi and Ji [84], Zivanovic [86] noted that walking speed follows a normal distribution pattern at a certain pacing rate, as shown in Fig. 17. Moreover, Živanović et al. [69] independently investigated the stride length of pedestrians from the data collected on Podgorica footbridge. It was observed that the stride length measurements fit a normal distribution with a mean value of 0.71 m and standard deviation of 0.071 m, similar to what had been proposed by Pachi and Ji [84].
Table 2, extracted from Pedersen and Frier [54], presents the mean value and standard deviation of step frequency reported by different authors.
A relevant comprehensive biomechanical study was conducted by Yamasaki et al. [89] to investigate the relationship between walking parameters such as speed, step length, and stance period taking gender into consideration. Interestingly, the authors reported a nonlinear relationship between walking speed v and step length Ls, which was in contradiction with several previous studies. This nonlinear behavior becomes more clearly observed at faster walking speeds as illustrated in Fig. 18. Moreover, the authors indicated that the step length for females is typically shorter compared with males especially at high walking speeds. Therefore, females tend to increase speed by increasing pacing rate, while males extend their stride length for the same purpose [89].
One of the first attempts to include the randomness effect into human-induced walking forces was performed in 1996 by Ebrahimpour et al. [90]. In their study on dynamic loads induced by crowds, they observed the significant effect of the erratic nature walking on the results. Furthermore, by including the probability distribution function of the time delay between several pedestrians, the authors achieved a design-oriented simple model that can be used to determine the first harmonic DLF provided the step frequency and the number of people, as shown in Fig. 19. On the other hand, they did not introduce such a comprehensive force model that can be practically applied to predict the structural response. More recently, the stochastic nature of walking was further emphasized in Refs. [11], [60], and [67] by the proposed DLF's of the first four harmonics of the human walking force (with 25% probability of exceedance).
Zivanovic [86] proposed an original framework based on probability theory which can be used to predict the vertical dynamic response of a footbridge excited by a single walking pedestrian. First, statistical analysis has been performed for the main walking parameters such as stride length, step frequency, force amplitudes, and walking imperfections. After that, the probability density functions of these parameters have been incorporated, making it applicable to calculate the cumulative probability that the vibration response will not exceed any certain limit, typically as shown in Fig. 20.
This way, the outcome can be used as a key factor which enables engineers to make a decision regarding the vibration serviceability of footbridge. It should be noted that the author [86] recommended to utilize this probabilistic model for the design of footbridges which are subjected to light traffic, where a single walking pedestrian loading case is predominantly expected. Nevertheless, a reliable representation for a single-person excitation was believed to be the first necessary step toward developing a prospective probability-based model for multipedestrian loading scenario.
According to Zivanovic [86], the main weakness of the proposed model in the beginning was being limited to calculate the dynamic response considering only the first harmonic of walking force that is applied to a single vibration mode of the structure. This caused the model to be applicable only to certain types of structural systems, bearing in mind that some structures may respond to human-induced excitation significantly in several vibration modes at the same time. As a consequence, Živanović et al. [69] have extended this probability-based model to cover not only the main harmonics of the walking force commonly considered but also the subharmonics appeared in the frequency domain, as illustrated in Fig. 21.
In this model, the intersubject variability was considered via the probability density functions for walking frequency, step length, pedestrian weight, and main harmonic amplitudes. Because of the lack of measurement database for subharmonics, the corresponding force amplitudes were simply included as a function of the first harmonic's DLF, which might be argued as a weakness point of that model. Moreover, the intrasubject variability was essentially included in the force model through the phase angle, which was represented in the frequency domain with a random pattern uniformly distributed between (−π, π).
With knowing the dynamic properties of each vibration mode and applying the concept of modal supervision, the authors [69] established a comprehensive model which was able to calculate the vertical multimode response corresponding to multiharmonic walking excitation of a single pedestrian. The accuracy of this model was proved to be adequate based on the results collected from two footbridge case studies: One was simulated and the other was at full scale. The methodology proposed in Ref. [69] had the potential to form the basis of more reliable and modern design guides for vibration serviceability assessment.
A more advanced stochastic model was proposed by Racic and Brownjohn [92] for vertical human-induced walking excitations. At first, the authors generated a comprehensive database of measured continuous vertical walking load signals. A total of 824 vertical walking time histories were collected, utilizing an instrumented treadmill, from about 80 test subjects from both genders and with different weights, heights, and ages. Each individual was requested to walk at a self-selected pacing rate with a different walking speed for each measurement, resulting in at least ten actual recorded signals for human walking forces. Figure 22 shows a portion of actually measured force signal of 40 s period, normalized to subject weight. Moreover, Racic and Brownjohn [92] categorized the walking signals according to the pacing rate into 20 clusters, each of 0.1 Hz interval, as shown in Fig. 23. It was observed by the same authors that the class of 1.88–1.98 Hz range of pacing rates was the most frequent, indicating that it is generally the most comfortable for walking pedestrians. At each cluster, the signals data were separately analyzed, and the key modeling parameters such as autoregression coefficients were computed.
It should be mentioned that, in order to account for the walking imperfections (i.e., intrasubject variability), the authors in Ref. [92] represented the variations in the cycle period (T) of the signal by a series of dimensionless numbers τi, which is expressed as [92]
Display Formula
In addition, the authors' algorithm included calculation of the cycle impulse, which is defined as the integral of walking force over cycle period, distinctively for each single footfall of the signal. After that, the algorithm computed the normalized impulse, which refers to the ratio of the cycle impulse to the subject weight. Figure 24 shows a possible linear relation between the normalized impulse and cycle time which can be represented as
where Iw,i is the normalized impulse of the ith cycle, εi is the subsequent error at the ith cycle, and a0 and a1 are the regression parameters of values 0.05 and 1.05, respectively.
In summary, the complete procedures of generating the walking force signal for a given set of pacing rate and walking period are explained in Fig. 25. In the proposed algorithm, the number of cycles is initially calculated, followed by a selection of the key parameters according to the frequency cluster and ending with generating the force signal for this described walking activity.
The main shortcoming of this modeling approach is being numerically complicated, which makes it impractical for the design engineers compared to the simplified hand calculations utilized in the current design guides. The authors argued that the application of this model could be easy to use by the design engineers through a computer program which has a friendly user graphical interface. For instance, by simply entering the walking path, pacing rate, and walking duration, the designer will get the corresponding generated force signal as an outcome, and then, vibration response of the floor is consequently calculated.
Živanović and Pavić [68] conducted a comparison study on a primary school structural floor of which the dynamic properties had been experimentally identified in an earlier effort [93]. As shown in Fig. 26, the analyzed floor comprised four nominally identical parts, while each was made of prestressed beams, lightweight blocks, and nonreinforced screed layer on top. The vertical floor vibration responses were estimated from five different force models of a single walking pedestrian, and the results out of these models were analyzed and compared. The force models adopted in this study were as follows:
Model 1: Actually measured forces, obtained using an instrumented treadmill, for a single pedestrian walking through the longer direction on a path matching with the center line of the floor.
Model 2: A set of continuous walking force measurements obtained previously by Brownjohn et al. [55] using an instrumented treadmill.
Model 3: The deterministic force model proposed for low-frequency floors, which is defined in vibration serviceability design guide: CSTR43-AppG. The force model utilized the first four harmonics of the walking excitation [11].
Model 4: The deterministic force model proposed for high-frequency floors, which is also defined in the design guide: CSTR43-AppG. This model assumes the transient behavior of walking excitation and deals with each heel drop as a separate force signal [11].
The reason behind including force models for both high- and low-frequency floors was that the fundamental frequency of the structure was slightly lower than the 10 Hz limit, which was suggested in the design guide as a separation line between the two floor types. Therefore, it would not be clear which of the two behaviors the floor would respond to, so the authors decided to utilize both for investigation.
Model 5: The force model suggested by the authors, which was of probability-based nature as previously described in this section. Moreover, this model suggested that the floor response shall be collectively taken from the contribution of two models. The first one is similar to model 3 for the modes of natural frequency less than 10 Hz, while the second is close to model 4 and used for higher vibration modes [68].
As a conclusion to their effort, Živanović and Pavić [68] stated that, at certain circumstances, it could be misleading to select the methodology of vibration serviceability assessment based on simply the floor classification according to the fundamental frequency as suggested by most of widely used contemporary design guides. As a rationalization of this problem, the probabilistic force model suggested by the authors was strongly nominated as an alternative due to several reasons. First, it combined the effects of force modeling approaches for both low- and high-frequency floors, which makes it applicable for any floor with a natural frequency exceeding 3 Hz, and thus leads to the elimination of floor-frequency classification. Moreover, the outcome of this model is presented as a probability of nonexceedance, which allows more space for engineering judgment.
Two main requirements are needed to achieve a force model which is practical to utilize at the design stage:
However, because of the random nature of human activities in general, it has been challenging for the researchers in the past decades to come up with design steps satisfying both conditions at once. As a consequence, there is no such design code known to be "enforced" for vibration serviceability assessment of floors [19]. What have been published so far are some "design guides," which generally include simple instructions recommended by experts to deal with human-induced floor vibrations in the design stage. These guides explain design procedures and different methods of handling the problem along with their limitations. Even though they are officially published by recognized institutions, the engineer has some freedom not to strictly follow these guides in case of providing reasonable arguments, such as introducing new materials or structural systems [19].
The most common guides, including the AISC Design Guide 11 (U.S., steel-framed floors) [13], Concrete Society Technical Report 43 (CSTR43) Appendix G (UK, posttensioned concrete) [11], SCI P354 (UK, composite floors) [12], HIVOSS (EU, steel-framed/composite) [94], and the UK Concrete Center Design Guide [11], utilize the deterministic approach to walking force modeling, with some differences such as the number of included harmonics and magnitudes of DLFs. For instance, the design value of a DLF is generally considered in the AISC Design Guide 11 as a constant dependent on the range within which the corresponding harmonic's frequency lies [13]. On the other hand, the Concrete Society Technical Report 43 (CSTR43) Appendix G [11], the UK Concrete Center Design Guide [11], and the SCI P354 [12] consider the DLF as a linear function of the corresponding harmonic's frequency as per the model presented in Eq. (2). A slight difference is observed in the design values of DLFs proposed in SCI P354 [12] due to the consideration of different reliability factors. On the contrary, the design philosophy of HIVOSS [94] requires first to determine the value of a quantity called "90% one-step RMS" using the floor dynamic properties and provided set of graphs. This value is then compared with the allowable limits set by the design guide for different floor destinations [94]. What is more, probabilistic models have not yet been adopted in a design guide [5,19,68,95].
In addition, the authors perceive that having a large number of alternative floor vibration design guides with different methods of assessment contained therein has not served the international structural engineering community particularly well. This issue would become more noticeable when structural engineers are working across international boundaries. What is required as a rationalization of these design guides is an internationally recognized "best practice" to provide reliable prediction and assessment of floor vibrations under human actions.
This paper has considered a large body of prior scientific literature dealing with experimental measurement and mathematical modeling of vertical dynamic forces induced by a walking person. The earliest approaches were based on the assumption that measured loads were periodic but not harmonic. This could be observed in spectra of both load measurements and structural responses due to such loading. It was recognized that harmonics of pedestrian loading higher than the fundamental are also a potential cause of vibration problems. Hence, much effort was expended to defining pedestrian loading as a Fourier series and determining appropriate frequencies and amplitudes.
Two main types of building floors are presented in the literature in terms of vibration attributes. Low-frequency floors have at least one responsive natural frequency below 9–10 Hz, which is within reach of one of the first four harmonics of the walking force, thus allowing resonant build-ups. Fourier series representations are useful for predicting resonant responses of these floors. In contrast, high-frequency floors do not undergo resonant build-ups. Effective impulse representations are useful for predicting impulse responses of these.
In contrast to the traditional belief, human walking was recently demonstrated to be a narrowband random process. Therefore, it becomes necessary to employ stochastic analysis to achieve more accurate force modeling. Some excellent studies, aimed to stochastically represent these forces, have been conducted in the past few years. The established probabilistic force models have the potential to revolutionize the classical methods adopted in the current design guides, which are shown to be not very accurate. However, the authors believe that such an all-inclusive probabilistic force model does not exist yet, and further research is needed.
The following points are further suggested by the authors as key research needs:
More realistic data are required on statistical distributions of loadings for typical building floors.
More research effort should be spent to rationalize the sheer number of floor vibration design guides currently available, leading to an internationally recognized best practice that can be used by the structural design community worldwide.
It is required to develop a comprehensive stochastic model for floor dynamic loading taking into account pedestrian inter- and intrasubject variability together with typical patterns of floor usage.
Start points, end points, and walking paths on the floor should be determined utilizing a random model originally based on an analysis of video monitoring data. This model should include the effect of floor nonstructural details such as furniture, partition walls, electrical kits, and so on.
The duration needed by a single person to walk on the building floor at different timing of the day should be estimated using a random model developed from video monitoring data.
The financial support for this research was provided by Qatar National Research Fund, QNRF (a member of Qatar Foundation) via the National Priorities Research Program (NPRP), Project No. NPRP8-836-2-353. The statements made herein are solely the responsibility of the authors.
Components of vibration serviceability analysis
A single walk cycle. (Reprinted with permission from Racic et al. [19]. The original version was published by Inman et al. [35]. Copyright 1981 by Williams & Wilkins.)
Vertical force resulted from a single step. (Reprinted with permission from Racic et al. [19]. Copyright 2009 by Elsevier.)
Typical walking and running time histories. (Reprinted with permission from Racic et al. [19]. The original version was published by Galbraith and Barton [34]. Copyright 1970 by Acoustical Society of America.)
Vertical force patterns for different modes of movement activity. (Reprinted with permission from Živanović et al. [20]. The original version was published by Wheeler [51]. Copyright 1980 by National Academy of Sciences.)
Historical development of force modeling approaches
Walking speed and DLF as a function of pacing rate. (Reprinted with permission from Živanović et al. [20]. The original version was published by Yoneda [59]. Copyright 2002 by AFGC.)
DLFs gathered from different authors for the first four harmonics of the walking force. (Reprinted with permission from Živanović et al. [20]. The original version was published by Young [60]. Copyright 2005 by Elsevier.)
Comparison of the response behavior in (a) low- and (b) high-frequency floor due to successive steps. (Reprinted with permission from Middleton and Brownjohn [30]. Copyright 2010 by Elsevier.)
Effective impulse proposed as a function of pacing rate and floor's natural frequency. (Reprinted with permission from Racic et al. [19]. The original version was published by Willford et al. [67]. Copyright 2005 by SPIE.)
Autospectral density of the walking force. (Reprinted with permission from Živanović et al. [20]. The original version was published by Eriksson [72]. Copyright 1994 by Chalmers Publication Library.)
Measurement of continuous walking force using an instrumented treadmill. (Reprinted with permission from Brownjohn et al. [55]. Copyright 2004 by National Research Council Canada.)
Representation of simulated deterministic walking force signal in the frequency domain. (Reprinted with permission from Brownjohn et al. [55]. Copyright 2004 by National Research Council Canada.)
Representation of real continuous walking force in the frequency domain. (Reprinted with permission from Brownjohn et al. [55]. Copyright 2004 by National Research Council Canada.)
Appearing of the subharmonic amplitudes of the walking force in the frequency domain. (Reprinted with permission from Živanović et al. [69]. Copyright 2007 by Elsevier.)
Normal distribution of the step frequency for normal walking, reported after (a) Živanović et al. [69], (b) Matsumoto et al. [82], (c) Kasperski and Sahnaci [83], and (d) Kramer and Kebe [85]. (Reprinted with permission from Pedersen and Frier [54] with modifications. Copyright 2010 by Elsevier.)
Normal distribution of walking speed at 1.8 Hz of step frequency. (Reprinted with permission from Racic et al. [19]. The original version was published by Zivanovic [86]. Copyright 2006 by the University of Sheffield.)
Nonlinear observed relationship between step length and walking speed. (Reprinted with permission from Racic et al. [19]. The original version was published by Yamasaki et al. [89]. Copyright 1991 by Springer.)
DLFs of the first harmonic crowd-walking force as a function of the number of persons and step frequency. (Reprinted with permission from Živanović et al. [20]. The original version was published by Ebrahimpour et al. [90]. Copyright 1996 by ASCE.)
(a) Probability of the peak modal acceleration excited by a single pedestrian; (b) cumulative probability that the peak modal acceleration is less than or equal the value specified in the x-axis. (Reprinted with permission from Živanović et al. [91]. Copyright 2007 by Society for Experimental Mechanics.)
(a) The 80-step walking force time history measured by an instrumented treadmill for a single pedestrian, (b) DLFs appearing for the main and subharmonics in the frequency domain, (c) phase angle of forces in Fourier spectrum, and (d) period of walking steps. (Reprinted with permission from Živanović et al. [69]. Copyright 2007 by Elsevier.)
A portion of actually measured continuous walking force in a 40-s period. (Reprinted with permission from Racic and Brownjohn [92]. Copyright 2011 by Elsevier.)
Frequency-based categorization of actually measured walking force signals. (Reprinted with permission from Racic and Brownjohn [92]. Copyright 2011 by Elsevier.)
Linear relationship trend between normalized impulse and cycle time. (Reprinted with permission from Racic and Brownjohn [92]. Copyright 2011 by Elsevier.)
Algorithm for generating synthesized walking force signals. (Reprinted with permission from Racic and Brownjohn [92]. Copyright 2011 by Elsevier.)
Description of the four-parted building floor selected for the comparative study. (Reprinted with permission from Živanović and Pavić [68]. Copyright 2009 by ASCE.)
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Customize your page view by dragging and repositioning the boxes below.
The American Society of Mechanical Engineers
Sorry! You do not have access to this content. For assistance or
to subscribe, please contact us:
Sign in or create your free personal ASME account. This will give you the ability to save search results, receive TOC alerts, RSS feeds, and more.
Sign into or create your free personal account


text:
This postbaccalaureate certificate is for people who already possess a four-year college degree and wish to develop expertise in New Media, Art, & Technology without having to earn a whole new four-year degree. Students can be generalists, or they can specialize in an area such as graphic design, web design, studio art, or digital media. The certificate consists of only 18 credit hours - just six courses. Up to 3 credit hours can be transferred in from other universities.
Admission Requirements
Students must possess a baccalaureate degree from an accredited institution and be admitted to Indiana University as a regular student.
Specified Credit Hours (18 cr.)
Courses can be any courses listed in the New Media, Art, & Technology Bachelor of Arts degree, as long as you meet the following requirements:
- At least 6 credit hours must be at the 300-level or higher.
- No more than 3 credit hours can be taken in courses without the NMAT (previously NMCM) designation, such as English or Speech courses.
- NMAT-G 398 Internship In New Media, Art & Technology (previously NMCM-N 398/S 398) may not be counted toward the postbaccalaureate certificate.

subset: commoncrawl


text:
Marvel Daredevil Logo Men's White T-Shirt
Official Merch
(approx. $10.75 or €9.56)
was £11.99
- In Stock
- No Worries 14-Day Exchanges
- Official Merchandise
Fast Delivery by Royal Mail (3-5 Days)
Start by selecting your size
Product Info
The man without fear is here to inject some superhero style into your wardrobe! Blinded by a radioactive substance at an early age Matt Murdock soon finds that the rest of his senses are heightened beyond human capabilities and uses them to become the iconic Marvel superhero 'Daredevil'. This tee sees him launching into battle mode and will make a brilliant addition to your comic collection. Official Merchandise.
- Product Type: Mens T-shirt
- Product Code: 84696


text:
This article is in need of cleanup in order to comply with Encyclopedia SpongeBobia's Manual of Style. Please help this Wiki by making this article clean and tidy!
|Pacific Ocean
|First appearance:
|"Help Wanted"
|List of places
The Pacific Ocean is the ocean in which Bikini Bottom is located. It is also the home of the many other towns seen in the series.
The Pacific Ocean is the world's largest ocean, covering about 64 million square miles. It covers more than one-third of the Earth's surface. Much of what lives in it remains a mystery to this day.
It is the only ocean to appear in the series (besides the Atlantic Ocean in "Atlantis SquarePantis" since Atlantis would be in the Atlantic Ocean if it existed at all).
Bikini Atoll is a small island in the Pacific Ocean that is near the city of Bikini Bottom.
External links
- Pacific Ocean - Wikipedia.


text:
7 Ways to Use Keywords for Link Building Campaign Design
Keywords are a gateway to understanding how a market thinks, acts and buys. They're also the common language for most SEO and PPC teams, and a clear way of connecting revenues with their work in the eyes of upper management. This all makes keywords a natural place to begin discussing – and designing – a link building campaign. (Note:...Read more
Three Ways Keyword Grouping Improves Your Copywriting
Keyword grouping—organizing your keyword research into small groups of tightly related terms—benefits your search marketing efforts at pretty much every level. Some of those benefits are more obvious than others; for example, keyword groups are essential for cost-effective pay-per-click (PPC) marketing, since close-knit ad groups earn higher Quality Scores. It's less obvious, but keyword grouping is also beneficial for...Read more


text:
Derma E All Age-Defying Moisturizer, 2 Oz
Derma Esku: 030985004052
Misc: SPF 15. Natural Solution: Age reverse. Skincare solutions. Cruelty-free. Paraben-free. Eco-friendly. Natural ingredients. With astaxanthin and green tea. Helps fight visible signs of aging. www.dermae.com. Cruelty-free/gluten-free/vegan/pH balanced. Never any harmful parabens, phthalates, sulfates, petrolatum, mineral oil or artificial colors. Your purchase provides support to global communities and the environment through our partnerships with Special Olympics and The Paraguay Project. Natural Skincare: Solutions that work. Age-defying Moisturizer SPF 15 helps defy age while providing protection from sun damage. Combines a powerful antioxidant blend of astaxanthin, green tea, aloe and vitamin E with skin-friendly UVA/UVB sunscreen. This intensive moisturizer is easily absorbed and leaves your skin well hydrated and protected. Made in the USA.


text:
The hotel is an international standard establishment whose management places a priority on safety, cleanliness and comfort. The architecture and interior d�cor features contemporary design and facilities on offer to guests include a 120-seater restaurant, the Palm Tree Beer Garden as well as banquetting and meeting facilities for 100 persons. Guests are also offered a limousine service and a tour desk. The hotel comprises 105 guest rooms and 20 rooms with built-in kitchens. Further facilities on offer to guests include a 24-hour reception and check-out service, a hotel safe, a currency exchange facility and Internet access (charges apply). Guests may also take advantage of the room and laundry services for an additional fee and there is parking available for those arriving by car.
This hotel is located in the heart of Chiang Mai city and is an ideal base for holidaymakers.
The well-designed guest rooms come in the category of standard studios, deluxe studios and junior suites. All rooms include a private bathroom with a shower/bathtub as well as a direct dial telephone, satellite/ cable TV, Internet access and a fridge. They also feature a king-size bed, individually adjustable air conditioning and a safe.
The hotel features an outdoor swimming pool and a spa pool. Sports enthusiasts may also enjoy a work-out in the gym.
The hotel restaurant provides a daily breakfast and all day � la carte service.
MasterCard and VISA are accepted at this hotel.
Room Facilities:
Direct dial telephone
Satellite cable TV
Internet access
King size bed
Individual airconditioned


text:
What Our Clients Say About Us…
Criminal Justice Attorney With Over 40 Years of Combined Criminal Defense Experience
- As one of the best law firms in West Palm Beach, we are proud to defend the rights of the accused.
- Clients turn to our award-winning law firm for honest advice and aggressive legal representation.
- Our lawyers have handled thousands of cases and have successfully represented clients against everything from DUI to murder charges.
- Attorney Rick Hutchinson has a 9.4/10 rating on Avvo, a website where clients and colleagues can write reviews about legal professionals.
- With a top criminal defense lawyer by your side, you can fight the charges that have been filed against you.
Facing the criminal justice system can be a frightening and life-changing experience, whether it's your first time in trouble with the law or a subsequent arrest. At The Law Offices of Hutchinson and Huffman, our criminal defense lawyers believe that each and every client deserves a strong defense, coordinated by an experienced legal team.
A conviction in the criminal courts can lead to lifelong consequences that may interfere with your ability to get a job, rent an apartment, enroll in university classes and live a fulfilling, happy life. Our West Palm Beach lawyers represent clients facing misdemeanor and felony charges. Our goal is to help you find justice, while minimizing any penalties that you may face, including fines, probation and jail time.
A DUI arrest can happen to virtually anyone. One moment you're enjoying dinner with friends and the next, you're in handcuffs, being booked for and accused of drunk driving. What's more, you don't need to drink to get arrested for driving under the influence. A driving under influence may also involve illicit drugs and even prescription medications, taken just as the doctor ordered. Seniors are often targeted for this type of arrest, causing extreme distress to an honest, law abiding citizen.
A DUI conviction can result in the loss of your driving privileges, making it impossible to earn an income and care for your family. You could also face steep fines and even jail time, particularly if someone was seriously injured or killed in a traffic accident. And this says nothing of the embarrassment you may experience. But there is help. Trust an experienced DUI defense lawyer who will offer sound legal advice, while fighting for your interests and protecting your rights.
Drug Crimes
The State of Florida has some of the strictest drug laws in the United States, making a narcotic arrest all the more frightening. Good, hardworking people can struggle with the perils of addiction, while others may find themselves involved in a bad situation that rapidly spirals out of control.
Regardless of what circumstances led to your arrest, our experienced West Palm Beach drug lawyers are committed to defending your case and offering world-class representation as we strive to defend those accused of drug offenses, while working to minimize any adverse effects. An experienced criminal defense lawyer can handle both misdemeanor criminal cases and felony narcotic crimes, from simple possession, to possession with intent to distribute, trafficking and beyond.
Theft Crimes
A theft crime arrest can lead to intense embarrassment and shame. A conviction can result in a fine, probation or jail time. You could also face challenges when renting a home, enrolling in a university or even applying for a job – especially one that places you in a position of trust. A theft conviction can haunt you for decades to come.
A diverse array of people are arrested for theft crimes. Many have never been involved with the law before, making the situation even more distressing. A top West Palm Beach defense attorney will defend your case in a strategic, aggressive manner, working to bring about the best possible outcome.
Sex Crimes
Few things can be more harmful to ones reputation and stigmatizing than an unlawful intercourse offense arrest and conviction. Sexual misconduct spans a broad spectrum from sexual battery and rape, to lewd and lascivious conduct or unlawful sex with a minor. A sexual misconduct conviction can result in serious challenges when trying to get a job, rent a home and living a fulfilling, productive life. And in addition to a very troublesome "black mark" on your record, you could find yourself required to register as a sex offender.
A sex crime conviction can have extreme consequences, particularly for offenses that are also considered a violent crime. This only highlights the importance of trusting your defense to an experienced criminal defense lawyer who can devise a strategic approach to defend your case and fight for your freedom.
White Collar Crimes
White collar crimes are non-violent crimes, typically with a financial motivation. White collar crimes often involve individuals in a position of power or authority, including business professionals and government officials, amongst others. There are even cases where a business or political opponent may conspire to make another person appear guilty of a crime.
A conviction on a white collar crime can destroy your career and your reputation within the community, causing tremendous embarrassment. And that says nothing of the criminal penalties, which can include fines, restitution, probation and even jail time. One thing is certain: you need an experienced defense lawyer who can work hard to protect your interests. That's precisely what we provide here at The Law Offices of Hutchinson and Huffman.
Domestic Violence
A domestic violence arrest involving family members can be a very trying experience for all involved. Many domestic violence cases lack an objective, third party witness, resulting in a he said-she said situation. Many who are arrested for an act of household brutality have never been in trouble with the law before, so it's not uncommon for our clients to be not only embarrassed, but also frightened and uncertain of what to expect.
Domestic Violence cases tend to carry harsher penalties than a comparable assault and battery incident involving a stranger. This underscores the importance of hiring an experienced assault and battery lawyer who is familiar with the challenges that this type of case can involve. That's precisely why clients turn to the experienced legal team at The Law Offices of Hutchinson and Huffman.
The Hutchinson & Huffman Scholarship – $500
Apply Today
The attorneys of Hutchinson & Huffman, P.A. are among the most highly respected attorneys in the nation and firm believers in working hard to achieve your goals. Most college students need financial assistance to help pay for their degrees. However, many students are not eligible for federal student aid and must apply for private student loans. These student loans are costly to pay back and often leave recent graduates in overwhelming debt while they are looking for a job. Our law firm is proud to support college students by offering them a scholarship to help pay for their education.
The lawyers of Hutchinson & Huffman, P.A. established the 2017 Hutchinson & Huffman Scholarship to reduce the financial burden students experience while pursuing their undergraduate or graduate degrees. Our law firm feels privileged to provide a $500 scholarship to any student who cannot afford the price of a college education. There is no fee to apply, and if you are selected, you have no obligation to pay the scholarship award back. This scholarship is our gift to students who are seeking college degrees and need help with the high cost of an education.
Every student deserves the opportunity to focus on their studies, rather than stress about ways to pay for their tuition or living expenses. These young professionals will one day lead our country. Hutchinson & Huffman, P.A. presents this scholarship as an investment in their education and future career. To apply for the 2017 Hutchinson & Huffman Scholarship, you must meet all of the submission requirements. Students from any bachelor's or master's program are eligible to apply.
Eligibility Requirments
Every applicant must follow the criteria below to be considered for the scholarship:
- Applicants must either be a citizen or permanent resident of the United States.
- Applicants must have earned an annual income of less than $35,000 in 2016.
- Applicants must provide an email address and Facebook account.
- Applicants must be enrolled part-time or full-time in either an undergraduate or graduate program.
Essay Topics & Submission Types
Every applicant is required to submit an essay about one of the topics listed below. This college-level essay must be written in your own words and should be free of any typos and grammatical errors.
- What are you studying and where do you see yourself in 10 years?
- Who has been integral in your educational career and how have they inspired you?
- Why is a college degree important to you and your community?
- Describe your college experience? How has your life changed since starting your postsecondary education?
- What is the most challenging obstacle you have overcome in your life?
Essay Directions
Essays will only be reviewed if they are typed using single-spacing with a 12-point font. All essays must be original and submitted via email as a PDF or Microsoft Word Document (.PDF, .DOC, .DOCX).
Video Options
Instead of an essay, applicants have the option to submit a video with their application. The video submission should last approximately 3-10 minutes and must be uploaded or linked to the host website. This video is optional, but if the applicant submits one they must include a link or URL to the original video.
Video format: (.MP4 OR .FLX OR .AVI OR .WMV OR .MOV)
Winner Selection & Recognition
The winner of the 2017 Hutchinson & Huffman Scholarship will be selected one week after the application deadline. The $500 scholarship will be awarded to the student in the form of a check sent by the United States Postal Service.
Application Deadline
Deadline for submission: June 1, 2017.
How To Apply
- Applicants can choose to write an essay or film a video.
- Email your completed application to the following email address: [email protected]
- Include your name, age, contact information, high school or college GPA, and the URL for your Facebook account using the subject line "Scholarship Submission."
- If you submit a video, please provide us with the link or URL to the video hosting site.
- The winner will be announced via email and sent instructions on how they can claim their $500 scholarship. The winner must provide a primary form of identification (driver's license, ID, or passport) before receiving the award.
Frequently Asked Questions
How can I submit my application?
We can only receive an applicant's essay or video by email. Please send all submissions to [email protected].
How many times can I apply?
An applicant can only apply once. If you have a revised copy of your essay or video, it will be accepted if corrections are sent before the deadline. Applicants must follow the same submission guidelines and use the subject line "Scholarship Submission Edited."
Does your scholarship have any GPA requirements?
Although there are no specific GPA requirements to apply, students with a GPA of 3.0 or higher are typically preferred.
How will I know if I won?
The scholarship winner will be notified by email one week after the deadline. All application inquiries should be sent via email. No calls or letters will receive an update.
Can I still apply even if I don't have an email or Facebook account?
Every applicant must provide an email address and the URL to their Facebook profile. These are two requirements for the scholarship, and the applicant is encouraged to create an email and Facebook account before submitting their application.
If I receive federal student loans, am I still eligible to apply?
Any student that meets the eligibility requirements can apply. However, this scholarship is intended to help students who do not have the financial means to pay for college.
Can I still apply after the deadline?
Unfortunately, no late submissions will be accepted. All applications must be received before the deadline.


text:
Royal Oak
Suspected serial bank robber in custody, police say
By Tiffany Esshaki
Posted April 10, 2013
ROYAL OAK — They just happened to be in the right place at the right time.
That's what Lt. Dave Clemens said about how Royal Oak police were able to catch the person they suspect robbed more than seven banks in the metro Detroit area during the past few months.
At around 12:41 p.m. April 10, Royal Oak police officers responded to an armed robbery taking place at TCF Bank, located at 1811 Crooks Road. Clemens said police were notified of the robbery by a 911 call.
According to a statement released by the Royal Oak Police Department, a bank employee said that the robber entered the building with a handgun and demanded money from a teller.
Officers, who happened to be near the location, according to Clemens, saw the man fleeing the bank on foot. Officers chased the suspect to a vehicle parked at a nearby business. He entered the vehicle and fled the scene, starting a chase.
The pursuit continued through several more cities before it ended with the suspect allegedly striking a Southfield patrol car on 11 Mile Road, west of Greenfield. Beverly Hills, Berkley and Southfield officers assisted in the subject's arrest.
"One of our officers was in his car while it was struck by the suspect," said Lt. Nick Loussia, of the Southfield Police Department. "He only had minor injuries but was taken to the hospital, just as a precaution."
According to the police statement, they believe that the suspect, 49-year-old Derrick Dwayne Sebree, of Madison Heights, is the same individual involved with similar bank robberies in the area, including the Feb. 8 robbery of Comerica Bank on West Maple Road in Birmingham. The robber, known for his signature black clothing and ski mask, got away with $9,000 that day. The so-called "serial robber" is accused of robberies in Madison Heights, Royal Oak, Berkley and Beverly Hills. The first robbery in the suspect's alleged crime spree occurred Dec. 20. According to the complainant report from U.S. District Court, the gun Sebree allegedly used was determined to be plastic.
Sebree is charged with eight counts of bank robbery. He is currently being held without bond until a preliminary hearing scheduled for May 14 in U.S. District Court. Sebree's attorney, David Tholen, could not be reached for comment by press time.
C & G Staff Writer Jessica Strachan contributed to this report.
About the author
Staff Writer Tiffany Esshaki covers Birmingham, Bloomfield Hills and Bloomfield Township as well as Oakland County Parks and Recreation and Oakland County Animal Control and Pet Adoption Center. Esshaki has worked for C & G Newspapers since 2011 and attended the University of Michigan-Dearborn and Oakland Community College. She's the recipient of several awards from the Michigan Press Association and the Detroit chapter of the Society of Professional Journalists.
More from C & G Newspapers
Metro Detroit
Looking Back: Lakeside School, 1924
Harrison Township
Three local drownings shine light on swimming safety
Oakland County
Annual parade to light up the Clinton River
Harrison Township


text:
Discussion in 'Fan Zone' started by blindzebra, Jun 14, 2014.
The young no name defense will be just fine watch.
I remember it well. I won $25 bucks off of a 49ers fan when that team made the playoffs. I don't see near the potential and excitement surrounding this team. Some of that has to do with Romo and Witten approaching the end of their careers. The core group of good defensive players are gone as well. By the time the defense is fixed, the team will be looking for a QB. In the past, Jerry has struggled in that area. The timing stinks for all areas of this team to come together at the same time.
I see some of the culture of how those Cowboys were built. This team will have some young guys on defense and one nasty on offense. Don't give up on them now...like a troll.
I think that was a post by my two year old grandson when he had my phone. He has strong opinions on the topic.
There is no telling where this team will end up. I really hope we have enough health to be able to evaluate the team.
When this team starts beating winning teams....and stops beating themselves in games and the coach quits botching plays then I'll believe.
Well then, if we're not comparing talent levels then I guess this team reminds me of the '92/'93 Cowboys teams. Both have a HC, an offense, a defense and special teams. Of course the talent levels aren't the same but other than that this years team is just like those SB teams!
And like that team, if we want to have any chance we'll have to bring in a new coach.
Very legit worry right there.
But also the defensive core
QB... coming off pretty serious back surgery. If health, I agree this is a "Check"
Running game... it will be a "check" when the coaches commit to running the ball. Not a "Check" until they do.
OL becoming a strength... agreed and HALLELUYA finally a "Check"
Explosive receivers... I'd say we have 1 explosive WR. I'll give it a half check.
A young and fast defense with something to prove... ummmm, check? But it doesn't mean they'll do anything. They might just prove that they do, in fact, suck. Technically a "Check" due to your wording, but the defense has a long long long long long long long long loooooooooooooooooooooooooooooooooooooooooong way to go.
I see 9-7 as our best case scenario.
I just don't get excited anymore. Fool me once (Jerrah), shame on you. Fool me 17 times (years), shame on me.
That is probably closer to the truth than any wild speculation even the so called experts could come up with.
Two problems, Troy was about 24 years or so, Tony is 34.
Jimmy vs Garrett is laughable to say the least.
Count me in with those so-called experts guessing correctly yet again that the Cowboys will not be a contender this year.
Nah, we're going to pull a Denver 97-98.
OK but I've heard everything from 3-13 to 11-5 and a playoff appearance.
espn can throw stuff up against the wall with the best of them, what you heard and reality are completely different. Much like i heard a lot of sunshine pumping last year, 8-8 was reality despite many people looking at it straight in the face.
I am with you on this. Garrett has coached his way to four wins over teams with winning records IIRC.


text:
GraphicRiver Lady in front of Pink Signage 7996278
Stock Vector \ Decorative \ Borders
Signage \ Background \ WomanIllustration \ Signboard \ Template \ Pretty
Stock Vector - Lady in front of Pink Signage 7996278 by interactimages @ GraphicRiver
Stock Vector \ Decorative \ Borders
Illustration of a pretty lady in front of the empty pink signage on a white background
Layered: Yes; Graphics Files Included: JPG Image, Vector EPS; Minimum Adobe CS Version: CS.
A Young Cowboy; Different Packs and Containers; Animals in the Woods; Sea Creatures with a Duck; Pirate; Six Colorful Monster Heads ; Three Wooden Shelves.
Keywords: advert, advertisement, background, blank, board, cartoon, copyspace, corners, edges, empty, female, frame, girl, human, isolated, lady, menu, person, poster, quadrilateral, rectangle, rectangular, sides, sign, signage, signboard, space, template, white, woman.


text:
Teen Preg Ad
graphing quadratics
Ondas electromagnéticas
Objetivos1. Comprensión de los conceptos fundamentales relacionados con los medios de transmisión y la propagación de ondas.2. Conceptos básicos, similitudes y diferencias entre los campos electrostáticos y los dinámicos.3. Propagación de ondas en diversos materiales.4. Herramientas matemáticas necesarias para el análisis de medios de transmisión.5. Habilidades para el trabajo en equipo y el trabajo autónomo.6. Análisis y síntesis sobre los medios de transmisión más comúnmente em
Duke Chapel Live - 1/8/2012
Duke Chapel Live - 1/8/2012
Andrew (with Brandi)
Description not set
Huntsman, Paul make last New Hampshire pitches
Jan. 10 - Republican presidential hopefuls John Huntsman and Ron Paul greet primary voters and a mass of media outside a polling station in New Hampshire. Rough Cut (no reporter narration).
This square is an 'in-between' area. Hebden Bridge is to the west and Mytholmroyd to the south, Midgley and the moors to the east and Chiserley (Old Town) to...
A Simple Test Apparatus to Verify the Photoresponse of Experimental Photovoltaic Materials and Proto
Dennis J. Flood, Andrew R. Barron
Some Rights Reserved
Hand Tools 3
Hand Tools 7
River Severn - The Shropshire Severn
Continuing the photographic journey from source to sea
15.389A Global Entrepreneurship Lab: Asia-Pacific (MIT)
15.389A Global Entrepreneurship Lab: Asia-Pacific enables teams of students to work with the top management of global start-ups and gain experience in running, and consulting to, a new enterprise outside the United States. The focus is on start-ups operating in emerging markets throughout the world, with a special focus on the Asia-Pacific region. The course combines an internship in a growing firm with in-class discussions of the issues and policies that affect the climate for innovation and st
ESD.00 Introduction to Engineering Systems (MIT)
Students in ESD.00 work on projects to address large, complex and seemingly intractable real-world problems, such as energy supply, environmental issues, health care delivery, and critical infrastructure (e.g., telecommunications, water supply, and transportation). The course introduces interdisciplinary approaches - rooted in engineering, management, and the social sciences - to considering these critical contemporary issues. Small, faculty-led teams select an engineering systems term project t
21F.405 Germany Today: Intensive Study of German Language and Culture (MIT)
Prepares students for working and living in German-speaking countries. Focus on current political, social, and cultural issues, using newspapers, journals, TV, radio broadcasts, and Web sources from Germany, Austria, and Switzerland. Emphasis on speaking, writing, and reading skills for professional contexts. Activities include: oral presentations, group discussions, guest lectures, and interviews with German speakers. No listeners.
Egyptian Sarcophagus Paper-Craft
This video shows the assembly of a paper-crafted Egyptian sarcophagus.
( This set shows a set of three nesting boxes.) Teachers could show this to students studying Egyptian history before having them design their own sarcophaguses. ( 4:17)
Sulfur Hexafluoride
It's not magic, kiddo. It's science! Sulfur hexafluoride (SF6) is a colorless, odorless gas that is more dense than air at 6.12 g/L (at sea level). This density is why you can pour it into a glass container and float a light-weight aluminum "boat" on its gas "sea." Watch this demonstration at the Physikshow of the University of Bonn! (0:30)
What in the World is a Tapir?
This is one confusing animal. It's often called a "mountain cow" but is actually related to the rhinoceros. It has a flexible nose like an elephant. (It has fourteen toes!) (01:48)
Persuasive Commercials
This classroom of students made commercials using different tools of persuasion. A teacher could show the video pausing after each commercial to discuss whether the students were using stereotyping, repetition, endorsement, association, etc. (14:57)
Jascha Heifetz plays Tchaikovsky Violin Concerto: 1st mov.
Jascha Heifetz plays Tchaikovsky Violin Concerto in D Major, Op. 35: I. Allegro moderato


text:
Sean Slevin, LPC, LMFT, NCC
Licensed Professional Counselor, Licensed Marriage and Family Therapist, National Certified Counselor
250 East Market Street, Suite D, Harrisonburg, Virginia 22801
Often the relationships we cherish the most are also the places where we experience the most discomfort. We can feel all sorts of variations of misunderstood, unheard and uncared for (and often our partner feels similarly). The good news is that growth and healing are possible. Our brains are built for relational healing--we just need help getting unstuck sometimes. I would be honored to walk with you and your partner in helping you both to better understand yourselves, and each other, in the places where you are experiencing difficulty. And in so doing help you both to experience each other in richer, more meaningful ways.
John Raymond, MA, MS, LPC
Licensed Professional Counselor
160 Warrior Dr., Stephens City, Virginia 22655
Sometimes it's worse being alone in bed with a partner than being alone in bed. Other times the conflict seems unresolvable. How do we handle relationship issues? Understanding is key. Understanding of self and your partner are vital. With your goals in mind, I provide hope. Hope meaning, developing a plan and helping you see you can do the plan. I can help you in one of our offices or online. My wife Janet is also a therapist. Find out more JohnandJanetRaymond.com


text:
Sept. 27, 2007
LARAMIE, Wyo. -
For the first time this season, the Wyoming volleyball team will play a home match at the UniWyo Sports Complex. They will host the 23rd ranked BYU Cougars, on Friday, September 28, and then the Utah Utes, on Saturday, September 29. Both matches are set to begin at 7 p.m.
Both live stats of each match and live video streaming will be available on this site.
"I'm very excited to finally play at home," said UW head coach Pat Stangle. "We have a great home court, fans and it will be nice to play in front of them. Both BYU and Utah are big and physical teams and will be ready to go when it's match time."
Wyoming enters the week with a 6-5 (.545) record and a 1-2 mark in conference play. The Cowgirls are currently led by outside hitter Rachel Smith, who is averaging 4.46 kills, which is third in the Mountain West Conference, and 2.54 digs per game. She is followed closely by senior Angie Hellbaum who is averaging 4.20 kills and 2.35 digs, while leading the way with the .267 (193-64-483) hitting percentage. As a team, they are averaging 14.91 kills, 15.67 digs and have a .224 (686-281-1808) hitting percentage.
The Cougars are currently 8-4 overall and 1-2 in the MWC. They are led by Chelsea Goodman who is averaging 4.35 kills and 3.44 digs per game. She is followed by Rachel Dyer who is adding 3.27 kills and 1.08 blocks, while Erica Lott is averaging 3.56 kills per game. BYU returns six starters and 11 letterwinners to a squad that went 25-6 overall and 13-3 in the MWC. This is the 60th meeting ever between the two schools. BYU leads the series 55-9. The last time the two teams met was November 11, 2006 as the Cougars defeated the Cowgirls 3-0. BYU is coached by Jason Watson who is in his third season with the program.
The Utes are currently 4-7 overall, 1-2 in the MWC and will play Air Force before facing the Cowgirls. They are led by Kathryn Haynie who is averaging 3.71 kills and 1.91 digs per game. She is followed by Whitney Webb who is adding 3.27 kills and 2.07 digs. Utah returns four starters and ten letterwinners to a squad that went 28-4 overall and 16-0 in the MWC a year ago. This is the 61st meeting ever between the two schools. Utah leads the series 37-23. The last time the two teams met was Nov. 9, 2006 as the Utes defeated the Cowgirls 3-1. Utah is coached by Beth Launiere who is in her 18th season with the program.


text:
Student success stories
Choose Havant Sixth Form College and you can be confident you'll get the great results you need for whatever you want to do.
We know how much competition there is for university places and jobs. With the best A Level results in the area, Havant is the place to study if you want to achieve the best results possible.
Natalie Hibberd:
A*Communication & Culture A English Language A English Literature
Formerly: Portchester Community School
"I want to be a novelist, so I'm going to be writing and trying to get published. I've been through a lot the last two years, health wise and so this was such great news, I'm thrilled."
Adam Boxall:
A* Biology A Chemistry A Mathematics A* Physics
Formerly: Springfield School
"It's such a relief to collect my results. It's a dream come true, it just hasn't sunk in yet. I will be off to Cambridge to study Natural Sciences."
Kitty Chan:
A Biology A Chemistry A Mathematics B Extended Project Qualification
Formerly: Priory School
"I'm ecstatic and overwhelmed - I just don't know how to process everything. It hasn't settled in that I'm going to university to study veterinary medicine at the Royal Veterinary College."
Lawrence Pople
Established the Politics Society
A* Government & Politics A History A* Law A Extended Project Qualification
Formerly: Admiral Lord Nelson School
"I'm happy and relieved I've got into the University of York to study History & Politics. I am really excited for the future."
Frances Osborne:
Established the Gender Equality Society this year
A* Biology A Chemistry A* Government & Politics
Formerly: St Philip Howard Catholic High School
"I'm shocked but excited with my results and the future. I'm happy to get through the two years and get my A in chemistry particularly. I'm looking forward to learning more as I will be going to UCL to study Arts and Sciences."
Aaron Lloyd:
A Biology A Chemistry B Maths A Extended Project Qualification
Formerly: Admiral Lord Nelson School
"I got in so can't get much better than that. I'm going onto Biomedical Science at Surrey."
Beth Punnett:
A* Drama & Theatre Studies B English Language & Literature B Psychology
Formerly: Chichester High School for Girls
"I'm relieved and happy with my results. I hoped to get an A in Drama but A* is brilliant. I've an internship at the Globe for the next year and then will look at my choices for university or drama school."
Kayleigh Puttock:
C Further Mathematics B Mathematics A Psychology
Formerly: Ormiston Six Villages Academy
"I've done as I expected. There are only 35 apprenticeships on offer across the country in Actuary Science and so I feel very lucky to get the place."
Travis Kemp:
A Chemistry A* Further Mathematics A* Mathematics A* Physics
Formerly: Mayville High School
"I'm happy with my results. I've easily got into my course Chemical Engineering at Bath."
Tegan Pope:
A Biology B Chemistry B Geography A Extended Project
Formerly: Portchester Community School
"I'm pretty happy with how everything has gone. I'm off to study Veterinary Medicine in London, it's going to be expensive but worth it."
Shenzen Newman:
A* Further Mathematics A* Mathematics A* Physics C Extended Project Qualification
Formerly: Purbrook Park School
"The hard work has paid off. I'm excited about my next step onto university."