A region of interest based video synopsis methods, devices and systems are disclosed. One embodiment of the present disclosure pertains to a method of a server for generating a region of interest based video synopsis. The method comprises setting a region of interest (ROI) for an area tracked by a camera device communicatively coupled to the server in response to a receipt of region of interest configuration data. The method also comprises converting a video stream forwarded by the camera device while a moving object is active within the region of interest into metadata of the moving object. The method further comprises generating a video synopsis of the moving object active within the region of interest based on the metadata of the moving object.

Cameras, such as closed captioned television (CCTV) security cameras, are increasingly used to prevent crime. In some cities, tens of thousands of security cameras are installed to watch over suspicious persons or activities, thus raising a high expectation from the general public. However, such expectation had often been met with a poor result owing to the short attention span of a person monitoring the surveillance footage as well as the lack of manpower required to review the lengthy video footage. For instance, the attention span of an average person is about 20 minutes, and it can take a sizable manpower to review the surveillance footage recorded by several camera/recording devices 24 hours a day.
Video synopsis is an approach to create a short video summary of a long video. According to the method, moving objects are followed (e.g., tracked, traced, recorded, etc.), and video streams capturing the movements of the moving objects are converted into a database of objects and activities. Once the database is formed, when a summary of the moving objects is required, the moving objects from the target period are collected and shifted in time to create a much shorter synopsis video, in which the moving objects and activities that originally occurred in different times are displayed simultaneously.


A gear reduction unit includes an electric motor that rotatably drives a drive shaft, a magnet on the drive shaft and a Hall effect sensor close to the magnet. The sensor is supported by a connector transmitting power to the electric motor. The connector may be removable. The connector has a printed circuit board defining a plane, with the sensor being offset relative to the plane defined by the circuit board.

Geared motors are often linked to a control system using motor speed and/or position parameters. The control system receives these parameters from a Hall effect sensor linked to a magnet that is designed to deliver a magnetic field to the sensor. The characteristics of the magnetic field depend on the speed and/or position of the drive shaft.
One proposed structure mounts the magnet on the drive shaft of a geared motor and fixes the Hall effect sensor to the control system or a connector. A magnetic flux conductor forming a flux concentrator is inserted between the magnet and the sensor, allowing the magnetic flux to be guided toward the sensor. This proposed solution, however, undesirably allows part of the flux to be lost and not be guided toward the Hall effect sensor, which reduces the quality of the motor parameter detection. Moreover, the installation of the flux concentrator makes the production of the connector more complex.
There is a desire for a simpler gear reduction unit configuration to overcome the problems of the proposed structure.

Gear reduction unit and geared motor connector

ArvinMeritor Light Vehicle Systems-France


An integrated home based system to measure and report vital patient physiological data via telemedicine is disclosed. The integrated medical device is a personal, affordable, portable medical monitor, providing multiple critical vital sign data for real-time face-to-face communication with qualified health care professionals, direct from the comfort of your home (or wherever you may be travelling), whenever you need it. It is also linked to a secure patient medical record so the patient and/or healthcare professional can collect, archive and track information and trends.

While telemedicine is already a multi-billion dollar industry providing remote doctor-patient consultations, there is currently no inexpensive, integrated portable, "home-based" solution to connect a patient to a health care professional and relay fundamental physiological information in real time during the consultation. Neither is there a single product that can collect, record and archive this information as part of an addressable Patient Medical Record (PMR) that the patient can authorize the health care professional to monitor and analyze for trend anomalies, or access themselves independently.
Other "telemedicine" devices on the market today are simply single purpose or clumsily developed products, each with different support software (if any exists at all) and do not provide the tools necessary for a typical doctor-like consultation. The telemedicine industry does not have a unified, coherent system that is easy to use for home use (the term "home" is broadly interpreted herein to mean any non-hospital/clinic location, therefore, home could include school office, remote (non-hospital) site, etc.) by a patient that is able to collect and integrate data from different critical vital sign monitors and present it in real time for telemedicine sessions, or in a properly formatted record for later use.
Therefore, in view of the above, various systems and methods are described below that address the industry's deficiencies.

Integrated medical device and home based system to measure and report vital patient physiological data via telemedicine


A method and system of improving the performance of an embedded control system by reducing the complexity of an averaging process. An average windowing filter with an average window size is implemented. A first processed data value is retrieved from memory and a current data value is determined. A past data value within the average data window is determined and the difference between the current data value and the past data value is calculated. An average of the difference over the average data window size is then determined. Finally, an output signal is generated based on the sum of the average and the first processed data value.

The present invention relates to anti-lock brake and traction control and other embedded systems having simple and limited processing architectures. More particularly, the invention relates to a method and system designed to improve the performance of an embedded control system by reducing the complexity of averaging processes.
Anti-lock brake systems are installed in vehicles to ensure the best possible vehicle control and stopping distance during hard braking. Traction control systems are used to prevent wheel spin while driving in adverse weather conditions. Other braking and control systems are used to prevent or minimize skidding and other non-desirable vehicle movement.
Braking and similar systems use a hydraulic unit to modulate wheel pressure to keep wheels from skidding or spinning. These pressure modulations can excite the vehicle drive train. When the drive train is excited at its natural frequency, the speed of wheels attached to the drive also vibrates. Wheel speed is often determined by using an embedded controller and sensors that monitor wheel rotation.
Many embedded control systems use feedback control, which means that the control action of the control system is generated based on a feedback signal. Once the wheel speed vibrates, the feedback controller attempts to attenuate the vibration by modulating pressure at the wheel. However, due to the delay in the control system, these pressure modulations often worsen the drive-train/wheel speed vibrations. To reduce the sensitivity of the embedded controller to vibrating wheel speed, a low-pass filter with a low cut-off frequency is commonly used. However, this introduces large phase lag in wheel speed and acceleration signals, which in turn degrades the control performance of braking and similar control systems.
Accordingly, there is a need for an improved control system for braking, traction control, and other embedded systems that are affected by wheel speed vibrations. The inventor has found that satisfactory control performance in braking systems can be attained by using moving-window, averaging filtering with a window size matching the vibration period of the unfiltered wheel speed. (The filtered wheel speed is the mean value of the unfiltered wheel speed values.) The inventor has determined that a window averaging filter has better attenuation results in the amplitude of vibration wheel speed with less phase lag than prior systems.
The invention utilizes a moving window averaging algorithm. In one embodiment, the invention provides a method of window-filtering vehicle data. The method involves retrieving a processed vehicle data value from a memory, determining a current vehicle data value, retrieving a current data window size from the memory, and determining a past vehicle data value within a data window. A difference between the current vehicle data value and the past vehicle data value is then determined. The method also involves determining a quotient of the difference over the data window size and determining a new processed vehicle data value by summing the quotient and the previously processed vehicle data value. The size of the data window can be increased or decreased to accommodate changes in vehicle behavior, such as changes in the natural frequency of the vehicle drive train that occur when the coefficient of friction (often referenced using the Greek letter mu) of the surface upon which the vehicle is travelling changes or varies.
For example, when starting a vehicle on a split-mu road surface (e.g., one drive wheel on ice and the other on pavement), only the transaxle, a half shaft, and one wheel are considered to be part of the drive train for purposes of determining the natural frequency of the drive train. On a homogenous, low-mu road surface, the transaxle, both half shafts, and two wheels are considered to be part of the drive train for natural frequency purposes. In these cases, the vibrating system involves different components and the elasticity and boundary conditions of the vibrating system are different. Thus, the natural frequency is different for each circumstance.
Increasing the window size involves retrieving a previous data window size from the memory, determining a product between the previous data window size and the previously processed vehicle data value, determining a sum by adding the current vehicle data value to the product, and determining a current processed vehicle data by dividing the sum by the current data window size. Decreasing the window size involves retrieving a past data window size from the memory, determining a product between the past or previous data window size and the previous processed vehicle data value, determining a first sum by adding the current vehicle data value to the product, retrieving a plurality of past vehicle data values from the current window, determining a second sum by adding the plurality of past vehicle data values, determining a difference by subtracting the second sum from the first sum, and determining a current processed vehicle data by dividing the difference by the current data window size.
The invention also provides a control system. The control system includes one or more data sensors coupled to a controller. The controller includes a filter and a main routine such as an anti-lock braking software module. The filter may be implemented as an interrupt routine. The filter retrieves a first processed data value from memory, determines a current unprocessed data value, retrieves a window size from memory, determines a past data value within a predetermined data window, the difference of the current data value and the past data value, and generates an output signal by summing the quotient and the first processed data value.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.

Method and system for improving the performance of an embedded control system by reducing the complexity of an averaging process


An apparatus for generating plasma including a plasma generating vessel and a coil having a coil length and a first set of partially enclosing, longitudinally oriented conductive (PELOC) fingers and a second set of PELOC fingers. The PELOC finger sets are oriented along a longitudinal axis of the vessel with each partially enclosing a periphery of the vessel. The two sets of PELOC fingers are oriented fingertips facing fingertips and separated by an inter-set distance that is less than the coil length.

In the manufacture of semiconductor products, substrates such as wafers undergo deposition and etching processes to form features thereon. The processing of semiconductor substrates often leaves residues, such as polymer deposition, between processing steps. Atmospheric inductively coupled plasma torches have been employed to clean substrates in preparation for further processing.
To facilitate discussion, FIG. 1 shows a typical prior art atmospheric inductively coupled plasma torch 100, which includes a double-wall cylinder 102. Cylinder 102 is typically formed out of quarts or a similarly suitable material. A cooling gas inlet 104 permits a cooling gas, such as nitrogen or air for example, to be injected in between the cylinder walls to thermally regulate double-wall cylinder 102 during use. By employing an appropriate cooling gas, thermal damage to atmospheric inductively coupled plasma torch 100 due to the high heat dissipation from the plasma therein is prevented.
A coil 106 is shown wrapped around the outer periphery of double-wall cylinder 102. During use, a process gas (e.g., hydrogen or nitrogen) is introduced into the interior volume of cylinder 102 through process gas inlet 108. When an appropriate driver RF signal (e.g., at 40 MHz) is supplied to coil 106, coil 106 acts as part of a series LC resonance circuit to ignite a plasma from the process gas. To help cool coil 106 during use, the coil is designed as a tube allowing liquid cooling to flow through it.
The inductively coupled plasma formed within atmospheric inductively coupled plasma torch 100 is ejected from opening 120. The hot jet of plasma ejected from opening 120 may then be employed to remove or clean materials, such as unwanted polymer deposition after an ion implantation process, from substrates.
As is known, the induced voltage across coil 106 is a function of the frequency of the driver RF signal. At 40 MHz, a typical atmospheric inductively coupled plasma torch may experience up to 20 KV (peak-to-peak) between the ends of coil 106, for example. The high induced voltage is necessary for igniting plasma at typical atmospheric conditions.
However, the high RF driver frequency employed in the prior art (e.g., 40 MHz or higher) presents cost and engineering challenges. For example, many processing systems already employ lower-frequency RF sources (e.g., 10-30 MHz, such as 13.56 MHz or 27.12 MHz) for etching and deposition. Accordingly, components and expertise for designing, manufacturing, qualifying, and maintaining lower-frequency subsystems are readily available at lower cost. Further, tool-to-tool repeatability is improved when a lower driver RF frequency is employed.
The invention relates to methods and apparatus for improving plasma ignition in an atmospheric inductively coupled plasma torch in particular and in inductively coupled plasma tools in general.

Plasma ignition and sustaining methods and apparatuses


An ankle exercise device comprises a base frame, a heel rest, a rotational component, and a plurality of resistance bands. The resistance bands may be connected to the rotational component. The rotational component rotates 90 degrees to orient the resistance bands in either a horizontal or vertical direction. The heel rest may comprise a u-shaped cutout to cup a user's heel. The heel rest is adjustable to align the heads of a user's metatarsals between the resistance bands. With the resistance bands in the horizontal direction, the user may rotate the ankle in the plantarflexion and dorsiflexion directions. With the resistance bands in the vertical direction, the user may rotate the ankle in the inversion and eversion directions.

There are approximately 2 million acute ankle sprains in the United States annually. A history of ankle injury is a strong risk factor for future ankle injuries. There is a need for a device to strengthen the ankle properly using correct body mechanics without the need for skilled physical therapy. While strengthening the ankle it is imperative to perform all exercises properly. The current methodology for strengthening the ankle in a skilled physical therapy setting is through the use of resistance bands with the assistance of a therapist. The therapist holds the resistance bands in specific tensioning directions with the appropriate lever arm for specific muscle isolation, while also providing verbal and tactile cues to the patient for proper body mechanics. The goal of the therapist's interventions is to decrease compensatory and/or aberrant movement, decrease the risk of pain, decrease over-use of small muscle groups, and educate the patient.
It is normal for patients to be educated and provided with a home exercise program to perform these same exercises to maintain gains and allow for timely progressions towards goals of strength, stability, and safe mobility when standing, ambulating and mobilizing on all surfaces. Due to the complexity of the musculoskeletal structures and the biomechanics and kinematics of ankle joints, it is difficult for patients to perform the exercises properly without supervision. When performing home exercises, patients often have difficulty with proper band placement, consistent tension on the resistance band, and compensatory unwanted movement at the hip joint. Proper band placement difficulties include difficulties with proper placement of the contralateral foot to achieve the necessary direction of resistance. Inconsistent resistance band tension prevents standardizing and quantifying the load. Aberrant compensatory movement at the hip joint limits ankle strengthening. Further, with these difficulties patient non-compliance becomes a large factor where the patient become discouraged and is no longer able to perform home exercises perpetuating their ankle weakness, eliciting dependence on health care providers and increasing their risk for re-injury.


An assembly having a flexible enclosure, filled with a suitable pressure wave attenuating medium material having a lower acoustic impedance than water so as to reflect shock wave energy. This basic configuration can be mounted in the form of panels and attached to the structure it is intended to protect, in which case it will form a flexible barrier of low acoustic impedance and be orientated between the structure and the water or ground in contact with the structure. The pressure absorbing and attenuating medium that will reflect shock waves may be a gas, compressed air, a closed cell foam or expanded foam. The flexible enclosure may be made of rubber or plastic or elastomer. For certain types of foaming agents, the outer skin will harden into a suitable enclosure so that no discrete shell or enclosure is necessary.

Sometimes, stress builds within the earth to such a significant level that it must be relieved, typically by rupture or failure of material. This rupture, an earthquake, may release enormous amounts of energy in the form of heat and seismic waves and may result in significant displacement of land masses at the surface. During an earthquake, a very significant amount of energy is released in a period of time that may range from a fraction of a second to several seconds. This energy release can be compared to detonating a large explosive charge underground, as the effects of both share several similarities. Energy released quickly during such events, produces a pressure pulse which radiates from the point of origin as stress waves. The size, profile and depth of the energy release area has an important bearing on the frequency of the vibrations. In the case of underground explosive detonations, if the release area is larger, and/or deeper, the frequency will be lower. If the release area is smaller, and/or closer to the surface, the frequency will be higher.
A pressure wave may move sonic or supersonic through the material it transits. A shock wave refers only to a pressure wave which moves faster than the sound speed of the material through which it transits. In this document, "stress waves" refer to pressure waves transiting a material at the sonic velocity of that material, and "shock waves" refers to pressure waves transiting a material above the sonic velocity of that material. Pressure waves and shock waves are traveling pressure fluctuations which cause local compression of the material through which they transit. Stress waves cause disturbances whose gradients, or rates of displacement are small on the scale of the displacement itself. Stress waves travel at a speed determined by the characteristic of a given medium and therefore must be referred to a particular subject medium.
Shock waves are distinguished from stress waves in two key respects. First, shock waves travel faster than the sonic velocity of the medium through which they transit. Secondly, local displacements of atoms or molecules comprising a medium that is being transited by a shock wave are much larger than those produced by stress waves. Together, these two factors produce gradients or rates of displacement much larger than the local fluctuations themselves.
Energy is required to produce pressure waves and once the driving source ceases to produce the stress disturbances, the waves decay. Absorption and attenuation involve acceleration of the natural damping process, which therefore means removing energy from the pressure waves. All matter through which pressure waves travel, naturally attenuate these waves by virtue of their inherent mass. Materials possess different acoustic attenuating properties, strongly affected by density and the presence or absence of phase boundaries and structural discontinuities. For example, porous solid materials are better attenuators of stress waves than perfect crystalline solids.
Acoustic impedance is the product of a material's sonic velocity multiplied by the material's mass per unit area. A material's acoustic impedance indicates how well it will transmit pressure waves. The higher the value, the greater (higher amplitude and/or higher velocity) the stress transmission in that particular material. Water has a density of 1 gram/cc, while air has a density of 1/1000 that of water. Water has a sonic velocity of approximately 1650 meters per second and air has a sonic velocity of 344 meters per second. The ratio between the acoustic impedance of water to air is nearly 4,800. Different types of rock will have varying sonic velocities due to differences in densities, crystallographic structure and the presence of discontinuities.
During a large explosion in a solid (such as rock), and during an earthquake, the resultant pressure pulse is a series of waves. There are two main types of body waves originating from the interior of the solid, which have different particle motions and velocities. The first wave to arrive (i.e. fastest), at a given point from the origin of the energy release, is a compressional wave, usually called a "P-wave". The particle motion in the P-wave is a "push-pull" motion, radially away and toward the origin, or in other words parallel to the direction of wave propagation. The other wave is a shear wave, usually referred to as an "S-wave". S-waves are generally transversal waves and the article motion is perpendicular to the travel path. S-waves and other waves will arrive after the P-wave because they are slower. P-waves and S-waves are both volume waves since they propagate in a three-dimensional space. At interfaces between different media (for instance, at interfaces between ground and air, between ground and water or between layers of ground of very different elastic characteristics), different types of surface waves are developed.
During an earthquake, when the P-waves and S-waves arrive at the ground surface, other waves are also developed. The two primary surface waves are known as "Love waves" and "Rayleigh waves".
The first, and faster of the two, are Love waves, whose motion is essentially the same as that of S-waves without vertical displacement. Love waves move the ground from side to side in a horizontal plane parallel to the earth's surface but transverse to the direction of propagation. The second, most prominent and common surface waves, are Rayleigh waves, or "R-waves" (elastic wave). P-waves, S-waves and R-waves produce vertical motion, whereas Love waves produce only horizontal motion. Rayleigh waves, because of their vertical component of motion, can affect bodies of water such as lakes, whereas Love waves (which do not propagate through water) can affect surface water only at the sides of lakes, water reservoirs and ocean bays, by a movement backwards and forwards, pushing the water sideways like the sides of a vibrating tank. The Love surface waves are the third to arrive because they travel slower than P-waves and S-waves. In the Rayleigh wave, the particles are described in a retrograde elliptical motion. The vertical component of the particle motion as its maximum just below the surface, but thereafter diminishes relatively rapidly with depth. Rayleigh waves may be compared to waves generated when a rock is thrown into a pond.
Because the various waves travel at different velocities, the differences in their arrival times at the land mass depend on the distance traveled from their origin. Very near the origin, the waves are mixed and are indistinguishable from one another.
As the distance from the point of origin increases, the waves separate and it is possible to see the differences in their characteristics. If all three wave types are well developed, the P-wave has the highest frequency and the smallest particle motion; the S-wave has a lower frequency and larger particle motion; and the R-wave has a frequency still lower and a particle displacement that is still larger in amplitude.
Propagation of Elastic Waves
The elasticity of a homogeneous, isotropic solid can be identified by two constants, k and .mu..
k is the modulus of incompressibility or bulk modulus ##EQU1## for granite, k is about 27.times.10.sup.10 dynes per cm.sup.2 for water, k is about 2.0.times.10.sup.10 dynes per cm.sup.2
.mu. is the modulus of rigidity ##EQU2## for granite, .mu. is about 1.6.times.10.sup.11 dynes per cm.sup.2 for water, .mu. is 0
Within the body of an elastic solid with a density .rho., two elastic waves can propagate:
______________________________________ P-waves Velocity for granite, .alpha. = 5.5 km/sec for water, .alpha. = 1.5 km/sec S-waves Velocity for granite, .beta. = 3.0 km/sec for water, .beta. = 0.0 km/sec ______________________________________
Along the free surface of an elastic solid, two surface elastic waves can propagate:
Rayleigh waves Velocity C.sub.r <0.92 .beta. where .beta. is the S wave velocity of rock.
Love waves (for layered solid) Velocity .beta..sub.1 <C.sub.L <.beta..sub.2 where .beta..sub.1 and .beta..sub.2 are S-wave velocities of the surface and deeper layers, respectively.
The dimensions of a harmonic wave are measured in terms of period T and wavelength .lambda.. EQU Wave velocity v=.lambda./T (3) EQU Wave frequency f=1/T (4)
As a particle vibrates, its motion can be described in several different ways. It moves a certain distance from its resting position, which is termed "displacement". It moves in a repetitive cycle or oscillation a certain number of times each second, which is termed frequency, and is usually expressed in Hertz. Displacement alone does not express the intensity of a motion.
Something can move a great distance very slowly and not be damaged by that displacement. To assess damage potential, the rate or velocity of the displacement must be taken into account.
For simple harmonic motion, the relationship between displacement, frequency and velocity allows calculation of any of the three if the other two are known. EQU V=2 .pi.f D (5)
where V=peak particle velocity in inches per second (ips) PA1 .pi.=3.14 PA1 f=frequency in Hertz (cycles per second) PA1 D=maximum displacement (inches) PA1 also T=period=1/f PA1 and 2 .pi.f=the circular frequency or angular velocity of the particle PA1 Hence, D=V/2 .pi.f and f=V/2 .pi.D PA1 h=distance between water surface and lowest level of the structure ##EQU8## where C.sub.y =is a parabolic function of depth of water a.sub.h =peak horizontal ground acceleration from quake PA1 w 32 specific gravity of water PA1 h=height ##EQU9##
As mentioned earlier, a shock wave is a pressure wave which is transiting a material at a speed greater than its sonic velocity. This wave produces an abrupt pressure "jump" in the material. U.sub.s (shock velocity)>C.sub.B (bulk sound velocity), which means that U.sub.s is supersonic with respect to the material (in its initial state). Compressional shock waves act to accelerate the particles of a material in the direction of wave propagation. On the other hand, rarefraction waves (expansion, unloading waves) act to accelerate the particles of a material in the opposite direction of wave propagation. Rarefraction waves may also be known as reflection waves, as they are a result of a compression wave being reflected back towards its point of origin as a tensile wave.
In the case of shock waves, jump relations (which describe the changes across the shock front) are obtained from the conservation of mass, momentum and energy, known as equations of state or E.O.S. The Rankine-Hugoniot E.O.S. for shock waves are: EQU Mass: .rho..sub.0 U.sub.s =.rho..sub.1 (U.sub.s -up) (6) EQU Momentum: P.sub.1 -P.sub.0 .rho..sub.0 U.sub.s up (7) ##EQU3## When p.sub.1 >>p.sub.0, Equations (5) and (6) combine to give ##EQU4## During an earthquake structurally damaging energy may be transmitted through the ground at speeds higher than four kilometers per second. Ground motions from earthquakes are characterized by large displacements, low frequencies and long durations. Stress waves will be transmitted from the earth into a body of water and then traverse the body of water until they encounter another medium or material (which may be a structure).
When this stress wave hits a structure, it imparts particle velocity into the materials of the structure.
The term "coupling" describes the interface between two different (dissimilar) materials. The amount of coupling between materials is a function of area joining the different materials, the bond between the two materials, and a function of the respective a acoustic impedances of the two materials, as well as the direction of displacement of the stress waves.
As a spherical shock wave is transmitted into the medium departing from the point of origin (energy release) the shock wave amplitude and energy decrease with distance. For very high shock pressures, the deformation of the material accompanying the one-dimensional shock compression is plastic. But as the shock propagates radially from the point of origin, the amplitude decreases very quickly and soon reaches the limit termed the Hugoniot elastic limit (HEL). From then on, the deformation is purely elastic. Such elastic compression waves are stress wave, and they propagate at the sonic velocity of the material being transited.
When the stress wave travels into a new medium with a different acoustic impedance, part of the energy will be reflected and another part will be transmitted. Pressure within a structure will be called stress rather than pressure, and will be designated ".sigma.". To reiterate, the impedance of a medium is given by the product of the density .rho. and the sonic velocity c. Consider an elastic infinite medium through which a plane stress wave passes. The stress induced .sigma..sub.1 is the product of the density .rho..sub.1, the sound velocity c.sub.1, and the particle velocity v.sub.1, EQU .sigma..sub.1 =.rho..sub.1 c.sub.1 v.sub.1 (9)
which clearly stems from the conservation of momentum M (equation 7) in the Rankine-Hugoniot E.O.S. In general, if a plane compressive stress wave reaches a boundary which is not parallel to the wave front, four waves are generated. Two of these are reflected waves, moving back into the medium from which the original wave came, a shear wave and a compression or expansion wave; the other two waves, also a shear wave and an expansion or compression wave, are transmitted into the new medium.
Consider a simpler, special case when the stress wave has a normal incidence to the boundary. Then, a wave with stress level .sigma..sub.R and particle velocity v.sub.R is reflected back. Another wave is transmitted into the second medium which is assumed to have density .rho..sub.2. It has stress level .sigma..sub.T, particle velocity v.sub.T, and shock wave velocity c.sub.2.
According to equation (9), it follows that: ##EQU5##
The following conditions must be fulfilled assuming that the two materials are in contact with each other during the shock wave passage: EQU .sigma..sub.1 +.sigma..sub.R =.sigma..sub.T EQU v.sub.1 +v.sub.R =v.sub.T (11)
Combining equations (10) and (11) gives the following expressions for the stress levels of the reflected and the transmitted waves: ##EQU6##
From equations (12) and (13), it is apparent that the ratio .mu. between the impedances varies. If the stress wave travels toward a medium with the same impedance (.mu.=1), no reflection occurs (.sigma..sub.R /.sigma..sub.1 =0).
When a stress wave passes from rock to air, or more specifically, from rock or water to air, gas or foam, (.rho..sub.1 c.sub.1 >>.rho..sub.2 c.sub.2), i.e., .mu. is very large, so almost no energy is transmitted. If .rho..sub.1 c.sub.1 >.rho..sub.2 c.sub.2, i.e., .mu.>1, then the reflected compression wave will appear as a tensile wave. Finally, if .mu.<1, then the reflected wave is a compression wave.
The relationship between vibrations and damage to a structure is complicated for many reasons. Some structures are more solidly built than others, and have different dimensions, materials, methods of assembly, and types of foundations. Moreover, the intensity, type, frequency range and wavelength of the vibrations, and the direction of incidence of the wave fronts relative to the main axis of the structure all play important parts in the origin of damage.
In concrete structures, such as a dam, two causes account for added stresses during an event like an earthquake: the acceleration of the mass of the structure and the changes of water pressures.
There are two distinct water pressures which affect a structure in contact with water and which actg simultaneously during an earthquake. The first is hydrostatic pressure (due to the depth) P.sub.1, which is present before, during and after the earthquake. The second is hydrodynamic pressure (due to ground acceleration transferring energy into the water and the stress waves transiting the water and interacting with the structure) P.sub.2, which is caused by the earthquake and is not normally present. ##EQU7## where .zeta.=water density=1000 kg/m.sup.3 g=gravity acceleration.congruent. 10 M/s.sup.2
Hydrodynamic forces may be absorbed and attenuated very effectively through adiabatic compression of gas bubbles. As the pressure increases within the gas it will heat. The heat causes the gas to expand. If the pressure is still higher outside the bubbles, interface, it will be compressed again and then expand.
In the past various attempts have been made to protect structures from the effects of shock waves and stress waves from earthquakes, explosions and other large energy sources.
U.S. Pat. No. 5,174,082 shows material described as an "island" with mechanical properties different than that of the ground. The islands are anchored deep underground by cable. A variant listed is to inter-disperse wells 5 m to 30 m deep filled with a granular or pulverized material, among the islands.
U.S. Pat. No. 5,173,012 shows a vertical wall barrier between a rail line and a building. The barrier is intended to stop ground-borne noise and vibration from travelling through the ground. It is constructed of two parallel concrete walls with elastic mat sandwiched between the walls.
U.S. Pat. No. 4,484,423 teaches a trench intended to be as deep as possible (but at least 100 meters deep), installed near a ground based structure to be protected (perhaps 3-60 meters in the case of a conventional power station). The preferred fill in the trench is a liquid or other material with a low shear, or gas bags or other media which does not allow S-waves. This technique is obviously impractical for many reasons, especially in submarine applications involving a dam.
None of these prior techniques can protect a structure in contact with water or a submerged structure, from energy being transferred to it through the water. Further, these methods do not lend themselves to protecting the submarine portions of pre-existing structures from pressure waves.
Canadian Patent No. 2,699,117 asserts that in the context of submarine blasting, interposing an air curtain of reasonable density between the structure to be protected and the source of waves, the resulting pressures can be reduced by 90%.
U.S. Pat. No. 5,394,786 teaches the use of aqueous foam as a buffer medium to attenuate S-waves in the ground. Aqueous foam might be useful when attempting to attenuate S-waves in the ground but is of no use in submarine applications. No attenuation will be present in such applications because the impedance of the aqueous foam will be nearly identical to that of the water.

International Hydro Cut Technologies Corporation


A titration dosing regimen for the administration of controlled release tramadol analgesic to patients. The titration dosing regimen provides a significant reduction in the occurrence of adverse effects from the introduction of controlled released tramadol dosing, thus increasing patient compliance and medication tolerability.

Tramadol, which has the chemical name (+/−)-trans-2-[(dimethylamino)methyl]-1-(3-methoxyphenyl) cyclohexanol, is a centrally acting synthetic opioid analgesic that is effective for the management of moderate to severe pain. After oral administration, tramadol is rapidly absorbed and metabolized into the pharmacologically active metabolite mono-O-desmethyltramadol. Conventional release preparations in the form of capsules, drops and suppositories containing tramadol have been commercially available for many years for use in the treatment of moderate to severe pain.
The prior art addresses the titration dosage regimen for immediate release tramadol. For example, U.S. Pat. No. 6,339,105 discloses a dosage regimen for immediate release tramadol including about 25 mg on days 1 to 3; 50 mg on days 4 to 6; 75 mg on days 7 to 9; 100 mg on days 10 to 12; 150 mg on days 13 to 15 and 200 mg on days 16 to 28. Also disclosed therein is a dosage regimen for immediate release tramadol including 25 mg q.d. on days 1 to 3; 25 mg b.i.d. on days 4-6, 25 mg t.i.d. on days 7 to 9; 25 mg q.i.d. on days 10 to 12; and 50 mg t.i.d. on days 13 to 28. The dosing of a controlled release form is not addressed in U.S. Pat. No. 6,339,105.
Controlled release tramadol is known to elicit adverse effects, including nausea, vomiting, sleepiness, dizziness, itchiness, sedation, dry mouth, sweating and constipation.
Thus, a need exists for the development of an advantageous dosing regimen for a controlled release dosage form of tramadol. More specifically, there exists a need for a dosage regimen for a controlled release tramadol which significantly reduces the occurrence of and concomitant severity of adverse tramadol elicited side effects, and thus, reduces potential discontinuation by patients due to these effects and increases the number of patients who may successfully be treated.

Titration dosing regimen for controlled release tramadol


A method for producing a photographic silver halide emulsion containing silver halide grains having a silver chloride content of 50 mol % or more and at least 30% of the surface area of the grains comprising [111] faces is disclosed, wherein the silver halide grains are formed in the presence of at least one kind of compounds represented by formula (I): ##STR1## wherein R.sub.1 represents an alkyl group, an alkenyl group, or an aralkyl group; R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 each represents a hydrogen atom or a group capable of substituting for the hydrogen atom, R.sub.2 and R.sub.3, R.sub.3 and R.sub.4, R.sub.4 and R.sub.5, and R.sub.5 and R.sub.6 each may be ring-condensed, provided that at least one of R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 represents an aryl group; and X.sup.- represents a counter anion.

Silver chloride grains or silver halide grains having a high silver chloride content (the silver halide grains mean silver halide grains having a silver chloride content of 50 mol % or more and hereinafter are referred to as high silver chloride grains) are materials well-known in the field of the art and are practically used as light-sensitive materials for printing or photographic printing papers. The increase of the silver chloride content in silver halide grains has a merit in the following points.
(1) Since the solubility of the silver halide grains is increased, the development and the fix are attained in a short time and the light-sensitive materials suitable for rapid processing are obtained.
(2) The absorption in the visible region is reduced (the inherent light sensitivity is reduced) and the separability from the spectrally sensitized region is improved.
On the other hand, silver halide grains having [111] faces mainly as the outer surfaces (hereinafter, the silver halide grains are referred to as [111] type silver halide grains or [111] type grains) are well-known materials in the field of the art and in light-sensitive materials for general photograph, the [111] type silver iodobromide grains are most usually used. In particular, [111] type tabular grains have the advantages that the grains can be effectively spectrally sensitized owing to the large specific surface area (the ratio of the surface area to the volume), the covering power after development is large, etc.
In an ordinary production condition, the high silver chloride grains tend to become grains having the [100) faces as the outer surfaces (hereinafter, the grains are referred to as [100] type grains) and hence for producing the [111] type grains, a specific means is required.
Wey (U.S. Pat. No. 4,399,215) discloses a method for producing high silver chloride tabular grains using ammonia. However, in the case of the tabular grains produced by the method, silver halide grains having a high solubility are produced at a higher solubility owing to the use of ammonia, whereby it is difficult to produce the practically useful small-sized tabular grains. Also, since in the method, pH at the production is high as 8 to 10, the method has a disadvantage that fog is liable to form.
Maskasky (U.S. Pat. No. 5,061,617) discloses high silver chloride {111} type grains produced using a thiocyanate. However, a thiocyanate increases the solubility of silver chloride grains as the case of using ammonia.
Also, for forming the [111] faces as the outer surfaces in high silver chloride grains, a method of adding an additive (a crystal habit controlling agent (i.e., a growth modifier)) at the formation of the silver halide grains are known as shown below.
______________________________________ (U.S. Pat. No.) (Crystal Habit Controlling Agent) (Inventor) ______________________________________ U.S. Pat. No. 4,400,463 Azaindenes + thioether peptizer Maskasky U.S. Pat. No. 4,783,398 Dithiazolidine-2,4-dione Takada U.S. Pat. No. 4,713,323 Aminopyrazolopyrimidine Maskasky U.S. Pat. No. 4,983,508 Bispyridinium salt Ishiguro U.S. Pat. No. 5,185,239 Triaminopyrimidine Maskasky U.S. Pat. No. 5,178,997 7-Azaindol compounds Maskasky U.S. Pat. No. 5,178,998 Xanthine Maskasky JP-A-64-70741 Dyes Nishikawa JP-A-3-212639 Aminothioether Ishiguro JP-A-4-283742 Thiourea derivatives Ishiguro JP-A-4-335632 Triazolium salts Ishiguro ______________________________________
(The term "JP-A" as used herein means as an "unexamined published Japanese patent application").
As described above, various crystal habit controlling agents are disclosed but for producing more preferable high silver chloride tabular grains, the development of new crystal habit controlling agents has been desired.
As the properties required for the crystal habit controlling agents, it is particularly important that the crystal habit controlling agent does not reduce the photographic sensitivity and does not hinder the adsorption of dyes for spectral sensitization. In this point, the use of the azaindenes or the pyrimidines is undesirable.
Furthermore, Maskasky (EP 584817A1) discloses a method of desorbing the crystal habit controlling agent by lowering pH and then exchange-absorbing an oxacarbocyanine dye containing iodine, for keeping the form of [111] tabular grains. However, such the exchange absorption method becomes a large load in the production.

Production method of photographic silver halide emulsion


Cache coherency is maintained between the dedicated caches of a chip multiprocessor by writing back data from one dedicated cache to another without routing the data off-chip. Various specific embodiments are described, using write buffers, fill buffers, and multiplexers, respectively, to achieve the on-chip transfer of data between dedicated caches.

1. Field of the Invention
The invention pertains generally to computers. More particularly, the invention pertains to cache coherency in a chip multiprocessor.
2. Description of the Related Art
Multi-core computer architecture typically includes multiple processors on a single chip, referred to as a chip multiprocessor (CMP), and the chip also includes cache memory (referred to simply as 'cache'). Each processor has its own dedicated on-chip cache memory for fast access to the code being executed and the data being operated upon. The chip typically also has another level of cache that is shared by all the processors, and at least one additional level of memory exists off-chip (either main memory or a higher level of common cache) that serves as a uniform data source for the on-chip cache. Each processor may modify a cache line within its own dedicated cache by writing to one or more locations within its own dedicated cache. However, if multiple processors are operating with the same cache line, one processor may modify the cache line in its own dedicated cache while the same cache line in other dedicated caches remains unchanged. This creates a problem with cache coherency—not all dedicated caches will have the latest version of the cache line. To maintain cache coherency, whenever a processor requests data from a cache line that has been modified in another processor's cache, the requesting processor's cache must also be modified to bring it up to date before the requested cache line is read and used.
Traditional multi-core systems maintain cache coherency by updating a common memory source that is off-chip, such as main memory, and then updating the requesting processor's cache line from the common memory source. Because transferring data to/from off-chip circuits is so much slower than on-chip transfers, this slows down cache-coherency updates, and negates some of the speed benefit of using on-chip cache memories.

Transfer of cache lines on-chip between processing cores in a multi-core system


A motion compensation apparatus to provide block-based motion compensation, and a method thereof. A first motion compensation interpolator calculates a first interpolation pixel by reading a first and a second pixel corresponding to a motion vector of an estimated current block respectively from a current and a previous frame or field. A second motion compensation interpolator calculates a second interpolation pixel by reading a third and a fourth pixel corresponding to a motion vector of peripheral blocks adjacent to the current block respectively from the inputted current and previous frame or field. A candidate interpolation pixel calculator calculates a candidate interpolation pixel by allocating a predetermined weight to the first and the second interpolation pixels, among the current blocks. A motion analyzer analyzes the motion vectors of the current block and the peripheral blocks, and determines discontinuities between the blocks. A final interpolation pixel selector selects either of the first interpolation pixel and the candidate interpolation pixel as a final interpolation pixel, according to the discontinuities determined at the motion analyzer. Accordingly, by applying an overlap block motion compensation according to discontinuities between the current and the peripheral blocks, an image can be provided in which the block artifacts are removed or reduced.

1. Field of the Invention
The present invention relates to a motion compensation apparatus and the method thereof, and more particularly, to a block-based motion compensation apparatus capable of outputting an artifact-free image signal by discriminately applying an overlap block motion compensation (OBMC) technique only to blocks having block artifacts, and a method thereof.
2. Description of the Related Art
A compression technique enables reduction of data in size, while maintaining the contents of the data. One of typical methods of providing a moving picture compression is a moving picture experts group (MPEG) method.
The MPEG has been suggested in an effort to improve a data compression rate by removing temporal and spatial redundancy between each frame or field. The temporal redundancy is removed by a motion estimation which finds the most similar block between a previous frame or field and a current frame or field. The spatial redundancy is removed by a discrete cosine transform (DCT).
The motion estimation is generally carried out by a block matching algorithm (BMA). BMA estimates one motion vector per block by comparing two consecutive frames, namely, the previous frame or field and the current frame or field based on the assumption that pixels in the compared blocks move in a manner of translation.
The motion vector estimated at a transmitter is transmitted to a receiver together with a motion prediction error, such as Sum of Absolute Difference (SAD), which occurs between the current frame or field and the previous frame or field. Then, motion compensation is performed in the receiver using the current and/or the previous frame or field with the received motion vector, and the frame or field is adaptively restored according to the received motion prediction error.
However, when the compressed data is restored by the conventional method of motion compensation, block artifacts may occur in the restored image. The occurrence of block artifacts is a phenomenon that boarders between adjacent blocks that look discontinuous in the restored frame or field, resulting in a visually inferior image and deterioration of image quality. The block artifacts usually occur in the process of block-based motion estimation and the motion compensation.
Meanwhile, the conventional motion compensation method uses an overlap block motion compensation (OBMC) on the basis of entire blocks to prevent the block artifacts. However, the OBMC has another problem of causing a blurring throughout the image.

Apparatus to provide block-based motion compensation and method thereof


A net is located on the top surface of a truck trailer or box body on a truck that traps and holds in place snow or ice that forms on the flat tops of the truck or trailer. The mesh of the net aids in breaking up the snow or ice into smaller lumps and thus redices the hazard from sheet of ice or snow slipping from the top of trucks or trailers as they travel on highways. A plastic or rope mesh material held above the surface of the truck or trailer top is preferred.

This invention shows a cover for box style trailers that may be deployed on a permanent basis or unfurled as a cover for the trailer closed top that has mesh to hold and break into small lumps any snow or ice that collects on the top surface of the trailer.
The problem of debris or other material falling from open trucks loaded with garbage, gravel, dirt or other materials is a long and well documented problem that has resulted in a series of State and Federal requirements for covers on open trucks. The covers both hinder the escape of lumps or pieces of the contents of the open trucks and lowers the emission of particulates removed by the wind of passage. The rules cover such diverse materials as asphalt and corn shipments where covers reduce air polluting dust and vapors to gravel and garbage trucks where material blown out of the truck can hit and damage or hinder vision of other vehicles traveling on roads behind or alongside these open trucks.
There is a problem that is similar in hazards and effects with closed box tractor-trailers. These long flat top trailers in colder times and climates accumulate snow and ice when they are parked in inclement weather. The accumulation that can easily be several inches of ice of up to a foot or more of snow is not easily removed due to the flimsy structure of the trailer box and to the height and lack of access to the trailer box top.
The problem of snow or ice falling from truck tops has caused several serious accidents and there are consistent claims of cars with broken windshields and several reports of injury due to impact of snow and ice falling from the top of trailers.
At present the key art is based upon open truck covers. It consists of safety systems for vehicles and tarpaulin systems where in most cases novel methods of attaching a tarp to the top of an open truck by means of a fixed or traveling unroller and rewinder are employed. The recent U.S. Pat. No. 5,211,440 is typical where moving a handle allows a tarpaulin to be moved from a stored position to its uncovered position, the system being considered in the patent as a safety system.
Another type of truck cover is shown by Dimmer et al in U.S. Pat. No. 4,302,043 where a sidewise tarp is pulled by an unrolling cylinder attached to a universal joint to allow the rotation of the tarp containing cylinder over a series of supports or ropes along the top of an open, full height sided truck thus unfurling the tarp. There are many other systems that cover rolling or unrolling a tarp.
The phrase snow screen does occur in the patent literature as in U.S. Pat. No. 5,564,770 but while the phrase could cause confusion with the concepts herein, snow screens are a windshield covering structure that has interfilding and storing capabilities when the snowscreen is withdrawn. In these usages the word screen is used in the context of covering or blocking material sheltering a surface (windshield) from snow contact. Snow screens in the context of covers for windshields have become popular and exist with magnetic clips, as folded vinyl mats, and as various sun screen configurations.
The problem of snow buildup has been noted in aircraft where a variety of systems to deice or to blow ice from sensitive surfaces by use of flexing membranes, by mechanical disruption or by heat or solvent are known and used in today""s aircraft. In these applications removal of ice totally is required and the form of the removal and the effect of standing snow or ice buildup is not directly addressed since ice covered surfaces just do not work effectively.
Shipboard buildup of ice is also noted but again the rapid removal of ice buildup to prevent top heavy structures is the thrust of the technology and the form of removed material is not a concern with the ocean as a dumping area.
This invention shows the deployment of a mesh containing top cover that is held slightly above the top surface of the trailer. The mesh containing cover has free spacing in the cells of the mesh such that any snow or ice that forms on the top of the trailer engages the mesh surface and is held by the mesh until such time it breaks up into mesh sized lumps and falls from the top of the trailer to the ground or road. The device thus prevents large slabs or lumps of snow or ice from falling from the top of trailers and hitting other vehicles.
Shoveling or even steam removal or automatic brushing of the top of trucks after each snowstorm or ice storm can of course accomplish the problem of minimization of damage from ice and snow on top of trucks. In actual practice the drivers are unlikely to do this since getting up on the ice covered truck is risky and the use of automated equipment is an avoidable cost to the truck owner or operator.
This invention provides a truck topping mesh layer supported a distance of one-eighth inch to six inches from the top of the truck on standoffs or rib-like frames. Since the truck top is an open mesh, the bulk of ice and snow falls through the mesh and is held on top of the truck as the truck starts on a trip. As the truck speeds up, normally the snow and ice would gradually get shaken loose and on a turn, a slowing or an acceleration period, the now loose snow would slip to one side of the truck body in one of more large sheets and fall to the ground. Sometimes there would be a car near that would be hit by the falling sheet of ice or snow. With this invention the mesh prevents the snow or ice layer from sliding to one side of the trailer. As the ice or snow layer becomes loosened from the trailer top, the mesh holds it. As the truck further speeds and wind and evaporation lighten and further loosen the snow or ice layer, the layer breaks up along the mesh cell boundaries and chunks and lumps that are about the size of the mesh break free and fall to the ground rather than large chunks or slabs. The smaller lumps are much less likely to cause harm than the large slabs and chunks. The buildup of ice would also be held in place, ice being more dense and harder to break, the ice would be held as it sublimates by action of the wind and truck speed. Ice would thus be held in place until it melts or breaks into small chunks.
The truck top mesh is held onto the truck in one of several ways. It can be attached to rails along the long axis of the truck, the rails providing further protection against sidewise slab slips. The mesh can also be held by standoffs located along the trailer top edges and throughout the top of the trailer. The standoffs, typically bolted or screwed on metal rods that have top clamps to grip the mesh, are one inch to 6 inches high and provide the required space above the trailer top to make the invention functional.
A considerable advantage to the truck mesh top is that it rapidly breaks up the snow or ice layer, thus rapidly lightening the truck and it further is removable for the 8 to 9 months when snow is unlikely. Being mesh, it has a low wind drag and in fact would fall within the envelope of static air formed by front cowlings on trucks that reduce wind drag effects.


A cutting blade for a motor-driven implement is provided. The cutting blade has a main body having a central fastening opening and blade sections that extend approximately radially from the main body. The blade sections have edges that extend in a radial direction and form cutting edges. Each blade section is provided with at least one bead-like embossment having a longitudinal axis that extends at an angle of between 0 and 45° relative to a longitudinal direction of the blade section.

The present invention relates to a cutting blade for an implement, especially a grass-cutting blade for a brushcutter or trimmer.
A cutting blade for an implement, especially a grass-cutting blade for a motor-driven brushcutter or trimmer, is known from U.S. Pat. No. 4,302,878. This known blade is essentially made of one piece from a main body having a fastening opening and blade sections that extend from the main body. The radially extending edges of the blade sections are embodied as cutting edges. The cutting blade is a reversible blade that is economically produced from plastic.
A cutting blade of the aforementioned type wears out relatively rapidly during continuous use, and in particular is not very suitable as a grass-cutting blade for professional use.
It is therefore an object of the present invention to provide a cutting blade for a motor-driven implement that is resistant to wear and is easy to guide.

Cutting blade for a motor-driven, manually-guided implement


Embodiments are disclosed that relate to calibrating an eye tracking system via touch inputs. For example, one disclosed embodiment provides, on a computing system comprising a touch sensitive display and an eye tracking system, a method comprising displaying a user interface on the touch sensitive display, determining a gaze location via the eye tracking system, receiving a touch input at a touch location on the touch sensitive display, and calibrating the eye tracking system based upon an offset between the gaze location and the touch location.

Eye tracking may be used in computing systems to detect user inputs made by gaze interactions with displayed user interface objects. Eye tracking systems may utilize images of a user's pupil and corneal reflections from glint light sources to determine a line of sight of the user's eye. However, different users may have anatomical differences that can affect such a determination. For example, the location of the fovea on the retina may differ from person to person. As such, the visual axis of the eye (i.e. the axis extending from the physical object imaged on the user's fovea to the fovea) may be offset from the optical axis of the eye (i.e. the axis extending through the center of the pupil to the back pole of the eyeball). As the image data is used to determine an estimate of the optical axis of the eye, such an offset may complicate the accurate estimate of an actual location at which the user is gazing.

Calibrating eye tracking system by touch input


The security system generally includes a key having an infrared transmitter and photocells which charge a power supply. The lock includes a pair of infrared receivers and a pair of light sources which charge the power supply in the key. The infrared transmitter in the key sends a key code to the lock via the infrared transmitter and the infrared receivers. A drive away prevention (DAP) module in the lock identifies the key code and enables the ignition of the vehicle.

The present invention relates generally to security systems, and more particularly to a vehicle system utilizing infrared communication and visible light for power coupling between a lock and key.
Current vehicle security systems typically include remote RF transmitters which transmit a security code to an RF receiver mounted on the vehicle. If a control module mounted on the vehicle recognizes the security code, the control module enables the ignition of the vehicle's engine. As is well known, the RF transmitted security code can be intercepted or "eavesdropped" by an unauthorized person with an RF receiver or a "code grabber." The unauthorized person can then later retransmit the intercepted code, unlocking the vehicle and enabling the ignition. As a result, many vehicle security systems have utilized complicated techniques involving encrypted or "rolling" security codes, in which, the RF transmitter continuously changes the security code. All RF transmitting systems have several other drawbacks. First, the RF transmitter must include a power source, such as a battery that degrades over time and must be replaced. Further, the RF signal can be jammed by RF or electromagnetic "noise," preventing operation of the RF system.
One known system utilizes an infrared transmitter on a key fob. An infrared receiver is typically mounted on the dome light or rearview mirror. The key fob transmits the security code to the infrared receiver, which then unlocks the vehicle. Although code grabbing is more difficult in this type of system, the security code can be intercepted by an unauthorized person. Further, the infrared transmitter includes a battery which degrades over time and must be replaced.
Another vehicle security system utilizes a small resistor mounted inside a key. When the key is inserted into the ignition lock, a circuit in the lock measures the resistance of the key. If the resistance value is recognized, the ignition is enabled. The system has two drawbacks. First, the electrical contacts on the key often wear out, become dirty or otherwise fail to make electrical contact with the lock, thereby preventing the owner of the vehicle from starting the engine. Further, unauthorized persons have developed keys having variable resistors which unlock any system of this type.
Another known vehicle system utilizes a small electronic circuit in a key which sends a coded signal via an RF transmitter built into the key. The RF transmitter is powered through electromagnetic coupling between the lock and the key. A coil on the lock provides an oscillating electromagnetic field which induces a current in a coil mounted in the key, thereby providing power to the RF transmitter. The RF transmission generated by this system can be intercepted as described above by unauthorized users. Further, the electromagnetic coupling which provides power to the key is relatively large, expensive and generates undesirable electromagnetic noise.

Optical drive away prevention security system


Provided is an electroconductive polymer composition with a good film forming property. Also, provided is an electroconductive polymer material with a high electroconductivity and a high transparency as well as an electroconductive substrate having the electroconductive polymer material on a substrate, and an electrode. Further, provided is an electronic device having the electrode as well as a solid electrolytic capacitor with a high capacitance and a low ESR. Disclosed is an electroconductive polymer composition, containing an electroconductive polymer in which a dopant is doped, a water-soluble polymer resin, and a solvent which contains water and an organic solvent whose dielectric constant is higher than that of water.

1. Field of the Invention
The present invention relates to an electroconductive polymer composition, an electroconductive polymer material, an electroconductive substrate, an electrode and a solid electrolytic capacitor.
2. Description of the Related Art
Electroconductive organic materials are utilized as an antistatic material or an electromagnetic shielding material as well as for electrodes of capacitors, electrochemical capacitors or the like, for electrodes of dye-sensitized solar cells, organic film solar cells or the like, for electrodes of electroluminescence displays, or the like.
As the electroconductive organic material, electroconductive polymers obtained by polymerizing pyrrole, thiophene, 3,4-ethylenedioxythiophene, aniline or the like are known. These electroconductive polymers are generally provided in a state of a dispersion liquid or a solution in an aqueous solvent, or in a state of a solvent in an organic solvent, and are used as an electroconductive polymer material after the solvent is removed.
Recently, an electroconductive polymer material with a higher electroconductivity is required, and it is variously studied. JP 2004-59666 A discloses a technology regarding an aqueous dispersion of a composite of a poly(3,4-dialkoxythiophene) with a polyanion and a method for producing the same, as well as a coating composition containing the aqueous dispersion and a coated substrate having a transparent electroconductive film to which the composition are applied. It is disclosed that a water-soluble compound having an amide bond, a water-soluble sulfoxide or the like is added to an aqueous dispersion of a composite of poly(3,4-dialkoxythiophene) with a polyanion in order to improve the electroconductivity of the coating film.
JP 2005-123630 A discloses a technology regarding a solid electrolyte produced from an electroconductive polymer, an electrolytic capacitor with a low equivalent series resistance and a low leakage current which consists of an outer layer containing an electroconductive polymer and a polymer anion, and a method for producing the same. It is disclosed that an additive such as an ether group-containing compound, a lactone group-containing compound, an amide or lactam group-containing compound, a sulfone or a sulfoxide, a sugar or a sugar derivative, a sugar alcohol, a furan derivative, or a polyalcohol is contained in order to further improve the electroconductivity of the electroconductive polymer.
JP 2000-153229 A discloses a thin film with a high electroconductivity which is obtained by applying a coating composition containing a non-protic chemical compound with dielectric constant ∈ of 15 or more to a substrate and by drying it at a temperature lower than 100° C.
However, to these electroconductive organic materials, not only high electroconductivity and high transparency but also good film forming property of the electroconductive film to the substrate to the substrate is required as an essential factor in order to actually use it as an electrode. The good film forming property means a state that a shrinkage, a crack, a wrinkle and foam of the film are not generated when the solution is applied and dried. Also, as a result, the electroconductive film with such good film forming property often has a high electroconductivity, a high transparency and a good adhesion to the substrate.
As a method for improving the film forming property, a method by adding an additive (solid or liquid), a resin (binder), a surfactant or the like is generally known. However, if this is mixed, the dispersion state of the electroconductive polymer composition is often deteriorated and a good film forming property is not obtained.
JP 2004-59666 A, JP 2005-123630 A and JP 2000-153229 A disclose that the electroconductivity is improved by adding an additive to an electroconductive polymer composition in which a polyanion is doped. On the other hand, these do not at all disclose the dispersion state and the film forming property of the electroconductive polymer composition. If an additive suitable for a component of the electroconductive polymer is not used, the dispersion state of the electroconductive polymer is deteriorated, and the increase of the viscosity and the particle diameter occurs due to the aggregation. As a result, the film forming property of the electroconductive polymer composition is deteriorated, and a shrinkage, a crack, a wrinkle and foam of the film are generated. Also, the transparency of the electroconductive film is deteriorated due to the increase of the particle diameter.
The object of the present invention is to provide an electroconductive polymer composition with a good film forming property. Also, the object of the present invention is to provide an electroconductive polymer material with a high electroconductivity and a high transparency as well as an electroconductive substrate having the electroconductive polymer material on a substrate, and an electrode. Further, the object of the present invention is to provide an electronic device having the electrode as well as a solid electrolytic capacitor with a high capacitance and a low ESR.

Electroconductive polymer composition, electroconductive polymer material, electroconductive substrate, electrode and solid electrolytic capacitor


Methods of fabricating a nonvolatile memory device are disclosed. A disclosed method comprises forming a first buffer oxide layer and a first buffer nitride layer on a semiconductor substrate; forming an opening through the first buffer nitride layer and the first buffer oxide layer; forming sidewall floating gates on sidewalls within the opening; forming a block oxide layer; forming a polysilicon main gate over the sidewall floating gates; forming first sidewall spacers on the sidewalls of the polysilicon main gate and the sidewall floating gates; forming common source and drain regions in the semiconductor substrate; filling the gap between the polysilicon main gates with an insulating layer; depositing a polysilicon layer for a word line; patterning a word line and the polysilicon main gate in the direction of a word line; and forming second sidewall spacers on the sidewalls of the word line and the polysilicon main gate.

1. Field of the Invention
The present invention generally relates to semiconductor devices and, more particularly, to methods for fabricating a nonvolatile memory device.
2. Background of the Related Art
Generally, semiconductor memory devices are divided into volatile memories and nonvolatile memories. The volatile memories, including chiefly random access memories (RAM) such as dynamic random access memories (DRAM) and static random access memories (SRAM), retain their memory data when the power is turned on, but lose the stored data when the power is turned off. In contrast, the nonvolatile memories, including chiefly read only memories (ROM), retain their memory data even after the power is turned off.
The nonvolatile memories may be subdivided into ROM, programmable ROM (PROM), erasable PROM (EPROM), and electrically erasable PROM (EEPROM).
From the view point of process technology, the nonvolatile memories may be divided into a floating gate family and a metal insulator semiconductor (MIS) family comprising a multi-layer of two or more dielectrics. The memory devices of the floating gate family use potential wells to achieve memory characteristics. For instance, EPROM tunnel oxide (ETOX) structure and split gate structure are widely applied to flash EEPROM. The split gate structure comprises two transistors in one cell. On the other hand, the memory devices of the MIS family perform memory functions by using traps positioned on a bulk dielectric, the interface between dielectrics, and the interface between the dielectric and the semiconductor. At present, the MONOS (metal oxide nitride oxide semiconductor)/SONOS (semiconductor oxide nitride oxide semiconductor) structure is chiefly being employed for flash EEPROM.
FIG. 1 is a cross-sectional view of a flash memory cell structure formed by using a conventional technology. Referring to FIG. 1, a gate oxide layer 12 is deposited on a semiconductor substrate 10 having at least one device isolation layer 11. A first polysilicon layer 13 is deposited on the gate oxide layer 12. The first polysilicon layer 13 is used as a floating gate. A dielectric layer 15 and a second polysilicon layer 16 are sequentially deposited on the first polysilicon layer 13. The second polysilicon layer 16 is used as a control gate. A metal layer 17 and a nitride layer 18 are sequentially deposited on the second polysilicon layer 16. A cell structure is patterned to complete a flash memory cell by removing some portion of the gate oxide layer 12, the first polysilicon layer 13, the dielectric layer 15, the second polysilicon layer 16, the metal layer 17, and the nitride layer 18.
For a conventional process of fabricating a NOR flash memory, a self-aligned source (SAS) process or a self-aligned shallow trench isolation (SA-STI) process is chiefly adopted to minimize the unit cell area of the NOR flash memories. Although the SAS or the SA-STI process or even both processes are applied, the unit cell area cannot be reduced down to 4F2 (F is the minimum feature size of the manufacturing process), the minimum area of a NANA flash cell, because a bit line contact should be formed. Moreover, in fabricating a device with 2 bit sidewall floating gates, bit line contacts have to be formed on source and drain regions to form bit lines. Therefore, an additional area is required to form the bit line contacts. As a result, a cell structure without a bit line contact should be developed to minimize the unit cell area.

Methods for fabricating nonvolatile memory device


An apparatus for the bending of a flexible conduit having first and second ends includes first and second assemblies which are fixed for relative rotation with the first and second ends. An axis of rotation passes through the first and second assemblies. The apparatus further includes a driven gear fixed for rotation with the first assembly. The driven gear is adapted to cooperate with a drive gear to rotate the first assembly with respect to the second assembly. The first assembly includes a first extendable portion which attaches directly to the first end. Similarly, the second assembly includes a second extendable portion which attaches directly to the second end. The first and second assemblies function to vary the distance between the axis of rotation and the first and second ends as the first assembly is rotated with respect to the second assembly.

1. Field of the Invention
The present invention relates, in general, to the transmission of fluids or electromagnetic waves. More particularly, the present invention relates to an apparatus for the smooth bending of a flexible conduit, such as a waveguide.
2. Discussion of the Related Art
It is well known that the propagation of electromagnetic waves can be guided through the application of conducting or metallic boundaries. If the frequency of an electromagnetic wave is high enough that the wavelength is comparable to the cross-sectional dimensions of the boundaries, then transmission between the boundaries becomes well defined. With uniform (non-tapered) boundaries, the voltage or current applied at the sending end of the boundaries determines the shape of the initial voltage or current wave. With boundaries having negligible losses, the transmitted shape remains unchanged.
Various devices have been employed in order to constrain or guide the propagation of electromagnetic waves along a path defined by the physical construction of the device. These devices include coaxial transmission lines and strip lines. Coaxial transmission lines consist of a dielectric material bounded by two coaxial, cylindrical conducting walls. Strip lines are constructed with a metal strip above a metal plane or with a metal strip between two metal planes. In either case, a dielectric material is used to insulate the metal strip and the ground plane or planes.
It is also known that the propagation of electromagnetic waves can be guided by using a waveguide. In a broad sense, devices such as coaxial transmission lines can be categorized as waveguides. However, in a more restricted sense and that used herein, the term waveguide refers to a metallic tube adapted to confine and guide the propagation of electromagnetic waves in the hollow space along the longitudinal direction of the tube. Hollow waveguides of convenient sizes are readily adapted to the transmission of microwaves.
While prior devices for guiding the transmission of electromagnetic waves have generally proven effective, they also have been associated with several disadvantages. For example, flexible waveguides are often used in microwave systems where rotation of part of the system with respect to the remainder of the system is required. An example of a system in which rotation would be desirable is a transmitter wherein it is necessary to guide electromagnetic waves between the transmitter and a rotatable antenna.
Simple rotation of one end of a flexible waveguide with respect to the other end using a fixed axis of rotation causes the effective length of the waveguide to become compressed. This compression often causes the waveguide to buckle. When buckling occurs, the stresses and strains involved can be expected to be higher than that encountered in simple bending. Such higher stresses and strains often lead to premature failure where the flexible waveguide is subject to repeated cycling.
Furthermore, buckling tends to change the effective length of the waveguide and often leads to undesired phase shifting of the transmitted electromagnetic waves. The greater the angle of rotation, the greater change in the effective length of the waveguide.
Thus, it is highly desirable to provide an apparatus which minimizes buckling of a flexible waveguide throughout rotation. That is, it is highly desirable to provide an apparatus for smooth bending of a flexible waveguide. Simple, uniform bending of a flexible waveguide provides a uniform level of stress and strain, at an optimal, minimized level. Further, as many flexible waveguides are designed to be cycled repeatedly during operation, reduced stress and strain levels can be expected to significantly increase component life and thereby decrease maintenance and replacement.

Apparatus for bending a flexible conduit


Disclosed is a computer-implemented method for estimating an uncertainty of a prediction generated by a machine learning system, the method including: receiving first data; training a first machine learning model component of a machine learning system with the received first data, the first machine learning model component is trained to generate a prediction; generating an uncertainty estimate of the prediction; training a second machine learning model component of the machine learning system with second data, the second machine learning model component is trained to generate a calibrated uncertainty estimate of the prediction. Also disclosed is a corresponding system.

Machine learning methods and lately especially neural networks and so-called "deep learning" methods are utilized widely in modern technology, for example in machine vision, pattern recognition, robotics, control systems and automation. In such applications machine learning is used in computer-implemented parts of a system or a device for processing input data.
Machine learning methods, for example based on artificial neural networks, can be used to generate, i.e. to construct, models based on input and output data. Such models may be e.g. classification, prediction or regression models, where after training the system with training data consisting corresponding inputs and outputs, the trained model may then be used to generate a "predicted" output corresponding to a provided new input. The generated output, e.g. a classification result, or any kind of other model output, can then be called the "prediction" and the model a "prediction model".
However, even though this methodology can be used to generate a model of a system, the models constructed in this way are often unsuitable for many applications, e.g. prediction or control applications. This is because the models, being automatically generated, are very complex and internally noisy, nonlinear mappings from input signals to output signals, and are not guaranteed to produce sensible outputs with all inputs. Thus it is uncertain if the model predictions are correct, or what are the confidence intervals of the predictions. Input data may also have inherent stochasticity, training data of the model can be limited so that the model is working outside the area where it is valid.
There is thus uncertainty in the outputs of a model. This uncertainty can be categorized into two types:                Type 1 ("aleatoric"): Uncertainty that has been observed in the training data, e.g. random noise in the input data.        Type 2 ("epistemic"): Uncertainty that has not been observed in the training data; e.g. an input data with no similar examples in the training data.
In case of a Type 1 uncertainty, the uncertainty in the prediction results from stochasticity inherent in the training data.
In case of a Type 2 uncertainty, the uncertainty generally cannot be estimated using statistical methods, as the problem is not stochasticity in the input data, but the internal modeling shortcomings in the model. Estimating this component of uncertainty of the outputs would require the model to detect unfamiliar data points, and to reflect that in the estimation of the prediction uncertainty.
Traditionally, data-driven methods (such as neural networks) tend to underestimate uncertainty for previously unseen data, meaning that they 'overfit' to seen data but lack extrapolative power that e.g. first principles models (e.g. those based on laws of physics, chemistry etc.) or some empirical models may have. While such first principles models are usually robust, even they may produce unreliable outputs when assumptions they were constructed with don't hold (e.g. errors in input data caused by a broken sensor, or an exceptional process operating point of a process producing the input data).
In order to use neural network models for prediction, classification and controlling tasks it is important to be able to estimate the uncertainty related to the model outputs, so that validity and reliability of the results and decisions based on the results can be predicted. Thus, there is need to develop mechanisms by means of which it is possible at least in part to improve determining the uncertainty of a prediction generated with a machine learning system.

This patent is subject to a terminal disclaimer.


Embodiments of the present disclosure provide a method and apparatus for predicting a severe convection weather. The method may include: acquiring a current radar echo map sequence, the current radar echo map sequence being a radar echo map sequence within a current time period; generating, based on the current radar echo map sequence, a future radar echo map sequence, the future radar echo map sequence being a radar echo map sequence within a future time period; and inputting the future radar echo map sequence into a pre-trained severe convection weather predicting model to obtain a severe convection weather intensity predicting map, where the severe convection weather predicting model is used to predict the intensity of a severe convection weather.

The severe convection weather refers to a disastrous weather with short-term heavy rainfall, thunderstorm, tornado, hail, squall lines, or the like. Such weather is destructive, and is disastrous with short duration, severity and strong destructiveness. The severe convection weather is listed as the fourth most disastrous weather in the world after tropical cyclones, earthquakes and floods.
The severe convection weather is most difficult to predict in all weather types. In addition, the severe convection weather is less available for research than the general weather types, and is difficult to predict accordingly. At present, the severe convection weather is mainly predicted manually by predictors. That is, experienced predictors track the latest radar echo map in time, and predict the severe convection weather by analyzing the cloud motion characteristics in the radar echo map.

Method and apparatus for predicting severe convection weather

BEIJING BAIDU NETCOM SCIENCE AND TECHNOLOGY CO., LTD.


An integrated circuit socket includes a housing having a flat plate portion and a plurality of contacts disposed in the housing. The contacts each have a contact beam projecting outwardly from a first surface of the housing and a retained portion disposed in a passageway in the flat plate portion. The contact beam extends from the retained portion. The retained portion has a base portion with a flat-plate shape and a pair of side portions extending at an angle with respect to the base portion on a pair of opposite sides of the base portion. A cross-section of the retained portion parallel to the first surface has a U-shape.

Integrated circuits (IC) have increasingly been subjected to large-scale integration; some ICs have 4000 to 9000 pads electrically connected to external portions. Contacts of a number equal to the number of the pads are correspondingly arrayed on such an IC socket. For example, Japanese Patent Application No. 2007-109520A discloses an IC socket including a housing and a large number of arrayed contacts. In recent years, ICs have begun processing high-speed signals such as a signal at 100 GHz. Therefore, it has also been demanded that IC sockets include contacts that can transmit such high-speed signals.
Each contact of an IC socket disclosed in JP 2007-109520A includes a retained portion, inserted into a contact retaining hole disposed in a housing, and a resilient arm protruding from the housing. The retained portion of the contact has a flat-plate shape. Such a contact is influenced by contacts arrayed adjacently to the contact, and therefore, it is necessary to evaluate signal transmission performance in consideration of the influence.
In a case in which a retained portion has a flat-plate shape, a distance between the portions to be retained of the contact and a neighboring contact arrayed adjacently to the contact in the direction of extension of the flat plate, and a distance between the portions to be retained of the contact and a neighboring contact in a direction intersecting the extension of the flat plate differ greatly from each other. Therefore, the level of the influence of a contact arrayed adjacently to the contact vary according to a direction in which the contacts are adjacent to each other. Such variations in the level of the influence according to the direction lead to the degradation of signal transmission performance. Accordingly, the contact of JP 2007-109520A transmits a high-speed signal at 100 GHz with great difficulty.

IC socket with contacts having a retained portion


A method, computer-readable storage device and an apparatus for planning tracking areas in a wireless network are disclosed. For example, the method represents geographical neighbor relations between each pair of base stations in a first set, and represents in a third set a plurality of potential assignment options for each base station of the first set to tracking areas in a second set, represents the historical data on paging traffic among the base stations in the first set via a first parameter, and represents the historical data on tracking area update traffic among the tracking areas of the second set via a second parameter, and determines for each base station in the first set, the optimal assignment of a tracking area in the second set.

A customer's ability to access wireless services that are provided by a network service provider, e.g., a wireless service provider, is dependent on the availability of capacity in the wireless network. The wireless service is provided to customers via various types of network elements, e.g., cell site equipment, core network equipment, and so on. The service provider needs to perform capacity planning for the various types of network elements.
However, the capacity planning requires consideration of many factors such as throughput, cost, ease in performing handovers, ease in tracking and paging of user endpoint devices, signaling overhead, etc. One approach for planning the capacity is manually manipulating parameters associated with each relevant factor until an experienced planner deems the result satisfactory. Unfortunately, this manual approach is labor intensive and highly non-optimal for capacity planning of large networks.

Method and apparatus for tracking area planning and optimization in a wireless network


A phase of a symbol on an inner or outer circle of a received 8QAM symbol set, which is bitmapped by being assigned one bit depending on whether the symbol is on the inner or outer circle of a constellation mapping diagram and two bits for each of the quadrants, is rotated to generate, by QPSK likelihood generation, along with a likelihood of a received QPSK modulation symbol, a likelihood for the two bits assigned to the quadrant of the 8QAM modulated symbol set whose phase is rotated. Further, the phase-rotated 8QAM modulated symbol set is phase-rotated to the first quadrant of the diagram to move the symbol set to the QPSK symbol mapping positions, thereby generating, by QPSK likelihood generation, the likelihood for the one bit assigned to represent whether the symbol is on the outer circle or the inner circle of the 8QAM modulated symbol set.

A likelihood used for soft decision error correction decoding is generally obtained by acquiring the minimum value of errors (Euclidean distances) between all symbol candidate points of a pattern presenting a transmitted bit of 1 and a received symbol, and the minimum value of errors between all symbol candidate points of a pattern presenting a transmitted bit of 0 and a received symbol, and converting a difference therebetween into a log likelihood ratio (LLR).
Calculation of the error (Euclidean distance) requires multiplications, and then, the minimum value needs to be selected from the plurality of candidates, resulting in an increase in a circuit scale. Further, if a circuit operating in real time is constructed, the real time property is secured by implementing likelihood generation circuits in parallel, resulting in such a problem that the number of multipliers increases as the number of parallelisms increases, which leads to an increase in the circuit scale of the likelihood generation circuit.
In contrast, for example, in Patent Literature 1, there is proposed a soft decision value generation circuit that reduces the circuit scale from the relationship of the symbol mapping by eliminating, in advance, an unnecessary calculation portion for the Euclidean distances to the symbols based on the relationship between the received signal and the mapping.

Likelihood generation circuit and likelihood generation method


In radio communication equipment, a ladder-type piezo-electric filter is provided which operates in a high-frequency region of approximately 1.7 MHz-2 MHz. The filter is smaller than conventional ladder-type electric filters, less costly, and more easily handled and produced. In accordance with the present invention, rectangular piezo-resonators that longitudinally generate harmonic oscillation are used in the series and parallel branches of a ladder-type circuit. In each resonator, piezo-electric regions are formed by dividing surface electrodes with isolating slits. The slits are formed at the positions corresponding to the node points of the harmonic oscillation waveforms. For the piezo-resonators placed in the series branches of the ladder-type circuit, the piezo-electric regions are polarized in the same transverse direction. In each piezo-resonator used in a parallel branch, the piezo-electric regions are polarized in alternately opposite transverse directions. In addition, the divisional electrodes of the parallel branch piezo-resonators are bridged over with a suitable conductor, such as conductive paint, or the like.

1. Field of the Invention
The present invention generally relates to a filter circuit for use in radio communication equipment, such as portable mobile radio equipment, a mobile telephone system, a cordless telephone, or the like, and particularly relates to a ladder-type piezo-electric filter to be used in a high-frequency region not lower than 1 MHz.
2. Discussion of the Related Art
Conventionally, ladder-type electric filters for radio communication equipment have been designed to operate with a center frequency of 455 kHz. As shown in FIG. 12, such a filter typically has a configuration in which piezo-resonators S, with resonance frequency at 455 kHz, and piezo-resonators P, with antiresonance frequency at 455 kHz, are inserted into series and parallel branches of a ladder-type circuit. Each piezo-resonator has a pair of electrodes placed respectively on the front and back surfaces of a square piezo-electric ceramic element. This filter, however, has the disadvantage that its size is large, as each of the piezo-resonators occupies an area of about 5 mm square.
To eliminate this disadvantage, a filter has been proposed which uses piezo-resonators that generate longitudinal harmonic oscillation. Each piezo-resonator has a pair of opposite electrodes placed respectively on the front and back surfaces of a rectangular piezo-electric ceramic element. Because its longitudinal or transverse size is at most 7/10 that of the square piezo-resonator, this filter has the advantages of a smaller size, a reduction in the amount of piezo-electric material used, and a lower production cost.
For the radio communication equipment of mobile telephone systems, there is a demand for a ladder-type piezo-electric filter of decreased size and capability of operating in a high-frequency region of approximately 1.7 MHz-2 MHz. Such a filter requires resonators of small dimension in both the longitudinal and transverse directions and, from the viewpoints of production and handling, is difficult to realize.


An integrated optical linewidth reduction system includes a phase modulator adapted to modulate the phase of an incoming optical signal in response to a feedback control signal defined by a first electrical signal. The phase modulator is further adapted to generate a first optical signal travelling through a first optical path. The first electrical signal is representative of a phase noise of the first optical signal. An optical linewidth of the first optical signal is less than an optical linewidth of the incoming optical signal.

The present invention is related to optical signals, and more particularly to reducing a linewidth of an optical signal.
Compact lasers with narrow linewidth are known and used in applications such as coherent optical communication systems, portable and non-portable high resolution LIDAR systems, mm-wave and THz signal generation, optical imagers, optical phased arrays, sensing, opto-electronic oscillators, molecular and bio-molecular spectroscopy devices, and the like.
Commercially available Sub-KHz fiber laser linewidths have been achieved at the expense of weak tunability, large form factor, small wall-plug efficiency, and undesired mode hoping characteristic. Using a conventional feedback technique to cancel phase noise over a large frequency bandwidth often results in feedback loop instability because the laser is part of the feedback loop. Thus, the laser's characteristics such as its FM response may effect the loop performance such as the phase noise reduction bandwidth. Accordingly, a need continues to exist for an optical signal linewidth reduction system that overcomes the shortcomings of the conventional linewidth reduction systems.

Integrated light source independent linewidth reduction of lasers using electro-optical feedback techniques