Methods and apparatus automatically detect alertness in humans by monitoring and analyzing brain wave signals. Steps include: acquiring the brain wave (EEG or MEG) data from the subject, digitizing the data, separating artifact data from raw data, and comparing trends in f-data to alertness indicators, providing notification of inadequate alertness.

It has long been accepted that in humans, blinking of the eyes serves to cleanse and lubricate the corneal surface, and that the rate of blinking and other measures of blinking could be attributed to environmental conditions (such as humidity and particulates in the air). It has also been postulated by investigators that blinking is strongly influenced by other factors such as fatigue and drowsiness, and may be monitored to provide some indication of alertness, which is used herein to mean the absence of fatigue and drowsiness.
The ability to measure alertness, or to detect the absence of alertness or presence of fatigue or drowsiness is desired. Many work assignments require a high level of alertness, often in environments not conducive to maintaining alertness. Examples of these are: nuclear reactor operators, aircraft pilots and other operators of complex equipment, air traffic controllers and others whose work environments provide little visual stimulus of a non-monotonous nature. Often consequences of lapses in alertness in these conditions can be grave, involving a high degree of hazard to life and property. It is this connection that has led the inventors to develop this method and apparatus for detection of alertness.

Method and apparatus for extraction of low-frequency artifacts from brain waves for alertness detection


Described are techniques for facilitating communications between a client and a server. A first communication connection is opened between the client and server and remains open for a duration of a session. In response to receiving a client request, a second communication connection is opened. The client request is sent over the second communication connection to the server. A first response is sent to said client over the second communication connection. The second communication connection is closed. The client request is serviced and a data portion indicating a status is sent to the client over the first communication connection. The data portion is included in a second response sent from the server to the client over the first communication connection. If there are other client requests received by the server and processed during the session, additional data portions for the other client requests are included in the second response.

1. Technical Field
This application relates generally to techniques for facilitating communications such as between a client and a server.
2. Description of Related Art
Computer systems may include different resources used by one or more host processors. Resources and host processors in a computer system may be interconnected by one or more communication connections. These resources may include, for example, data storage devices such as those included in the data storage systems manufactured by EMC Corporation. These data storage systems may be coupled to one or more host processors and provide storage services to each host processor. Multiple data storage systems from one or more different vendors may be connected and may provide common data storage for one or more host processors in a computer system.
A host processor may perform a variety of data processing tasks and operations using the data storage system. For example, a host processor may perform basic system I/O operations in connection with data requests, such as data read and write operations.
Host processor systems may store and retrieve data using a storage device containing a plurality of host interface units, disk drives, and disk interface units. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels to the storage device and storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical disk units, logical devices, or logical volumes (LVs). The logical disk units may or may not correspond to the actual disk drives. Allowing multiple host systems to access the single storage device unit allows the host systems to share data stored therein.
Different tasks may be performed in connection with a data storage system such as for data storage system management. A user, such as a data storage system administrator, may perform data storage system management operations and tasks to manage the data storage system. The user may perform the foregoing using a web browser located on a management computer system which is in communication with the data storage system so that the user can issue commands to the data storage system to perform tasks, view and obtain data storage system status information, and the like. The management computer system may include client management software executing in the context of the web browser which periodically polls one or more data storage systems to obtain data storage system state information. Each of the data storage systems may execute instructions to report updates to the client system management software in response to the polling request.
The foregoing technique may have existing drawbacks. The reporting by each data storage system at each interval may consume an unacceptable amount of resources of the management computer system on which the client management software is executing, the data storage system(s) being polled, and/or the network facilitating the communications therebetween. For example, the number of incoming messages to be processed by the management computer system increases with the number of data storage systems and may eventually saturate or "flood" the management computer system even though the returned polling messages indicate no change or insignificant change with regard to status. Additionally, reporting at periodic intervals means that any reported updates or events regarding data storage system status take at least until the next interval to be communicated to the management console so that reporting an important or significant event may be delayed until the next reporting interval. Thus, the management computer system may be displaying, for example, stale or outdated information or may be informed about an event within an unacceptable amount of time. Resources of the data storage systems may also be unnecessarily consumed by processing and reporting on data storage system state even though there may be no significant or noteworthy events.
Additionally, the client management software may include a web browser that communicates with a web server or other software on the data storage system using a standard communications protocol such as HTTP (Hypertext Transfer Protocol). Such protocols may have limitations, guidelines or recommendations which when implemented create a potential bottleneck in connection with processing polling requests and other requests from the client management software to perform data storage system management operations. For example, as known in the art, HTTP V1.1 has a two HTTP connection limit as a guideline adopted or imposed by some web browsers such that the web browser can only have two active logical HTTP connections to one given server in a domain at a time. In other words, at most two outstanding HTTP requests may be issued from the web browser to a web server for a particular domain name. As a result, if there are two outstanding polling requests each issued over a different HTTP connection to the web server, any subsequent data storage system management operation is not communicated to the data storage system's web server until one of the two connections closes. In typical HTTP communications, the HTTP connection is opened by the client, such as by the management computer system, when an HTTP request is communicated to a server. The HTTP connection is closed once the response has been sent from the server to the client. As such, outstanding polling requests may cause unacceptable delays in performing subsequently issued user requests for data storage system management operations that may be issued interactively or otherwise.
Thus, it may be desirable to have an efficient technique for reporting events and updates regarding one or more data storage systems in a timely manner. It may be desirable that the technique be scalable for use with a varying number of data storage systems and events occurring therein. It may also be desirable that such techniques provide for efficient use of resources.

Techniques for client and server communication


In an embodiment, a method finds an optimal set within collected data objects, each having a score and a list of incompatible objects. The method can include initializing a plurality of sets. Each set has compatible data objects. The method further includes raising the score of the plurality of sets by repeatedly adding compatible subsets of data objects to the plurality of sets. The plurality of sets have a higher score after adding the compatible subsets. The compatible subsets are created by (a) at each of multiple processors, generating a list of subsets of the collected data objects by loading the list of sets from a memory and testing data objects of the subsets for compatibility for each set, and (b) calculating a score for each subset in the list, each processor calculating the score for a particular subset in the generated list in parallel. The method further includes selecting a group of subsets having a highest score.

Multiple hypothesis tracking (MHT) is utilized to track multiple targets at the same time. MHT is generally described by Samuel S. Blackman in Multiple Hypothesis Tracking for Multiple Target Tracking, IEEE A&E Systems Magazine, Vol. 19, No. 1, January 2004, pages 5-18. In some scenarios, a plurality of targets is tracked via a long-term track-oriented approach for hypothesis management which reconstitutes the long-term track hypotheses. The reconstitution of global hypotheses in the long-term track-oriented approach is time consuming and the performance of this step significantly impacts MHT tracking performance. Furthermore, the reconstitution of global hypotheses within the track-based MHT is an NP-hard problem, and previous approaches (e.g., breadth-first search, depth-first search, etc.) are ad-hoc and do not provide performance guarantees.

Parallel hypothesis formation for multiple hypotheses tracking


A locking nut includes a main ring having a threaded bore, a front end face at one end of the bore and a counterbore at the other end of the bore. Actually, the threaded bore opens into the counterbore through a recess which in turn opens out of a shoulder that forms the end of the counterbore. The main ring also has threaded holes which open out of the recess around the threaded center bore. In addition to the main ring, the nut has a secondary ring which fits into the counterbore and against the shoulder of the main ring. In the region of the threaded holes the secondary ring is relieved to the extent that it has a lesser diameter than the recess. The secondary ring also has a threaded bore, the thread of which matches the thread of the bore for the main ring. Indeed, the threads for the two rings are cut in the same machining operation, so that no interruption in pitch exists between the threads of the two rings. Cap screws extend through the secondary ring at the recesses and into the threaded holes of the main ring, engaging the threads in those holes. When the cap screws are loose, the nut passes easily over the external thread of a threaded shaft or spindle. However, when the cap screws are turned down against the secondary ring, they deform the secondary ring in the region of its reliefs into the recess of the main ring, causing the threads of the secondary ring and main ring to in effect jam. The friction which develops locks the nut on the external thread.

This invention relates in general to a nut for securing a machine component on an external thread and more particularly to a locking nut which may be secured against rotation without changing its axial position, to a bearing assembly including the nut, and to a method of manufacturing the nut.
Locking nuts exist in a variety of configurations for securing machine components to spindles and shafts. One of the more important uses of locking nuts resides in holding bearings on spindles, particularly on spindles at ends of drive and steer axles for large trucks. The typical spindle on one of these axles carries two single row tapered roller bearings which are mounted in opposition, and the bearings in turn carry a hub, enabling it to rotate with minimum friction on the spindle. The inner races or cones of the bearings fit around the spindle, while the outer races or cups fit into the hub. The spindle at its end has a thread over which a nut passes, and the position to which the nut is advanced determines the setting for the bearings. Most automotive bearings are set near a condition known as zero end play, whether it be with a very slight amount of end play or a very slight amount of preload. Too much end play detracts from stability and the hub and wheel may wobble. This in turn produces excessive seal wear. Moreover, excessive end play causes the load zone in each of the bearings to concentrate at a few rollers, and this may shorten the life of the bearing. Excessive preload, or the other hand, imparts more force to the bearings and may cause the bearings to fail early.
While a variety of nuts exist for holding bearings in place on spindles, perhaps the most common is the jam nut arrangement. This basically consists of two nuts, one threaded up behind the other. Indeed, the first nut is turned down against the inner race of the outboard bearing until a desired setting is obtained. Any of several procedures are available for determining the setting. Perhaps the most basic is simply by feel. Then one can monitor the torque. One can also monitor torque and back off of a prescribed amount which is usually specified in terms of nut rotation. In any event, the first nut brings the bearing to a desired setting, and when that setting is achieved the thread of the first nut lies against the inboard flanks of the thread on the spindle, that is to say against the flanks which are presented toward the bearing. Next, with the first nut held against rotation, the second nut is advanced over the spindle and turned down tightly against the first nut, or more likely against a washer interposed between the two nuts. The threads of the second nut likewise bear against the inboard flanks of the spindle thread, and indeed the second nut drives the first nut slightly farther along the spindle--far enough to bring the thread of the first nut against the outboard flanks of the thread on the spindle. This changes the setting of the bearings and one must account for it when establishing the initial setting with the first nut. Thus, the traditional double nut arrangement does not lend itself to much precision.
Single locking nuts exist, and some of these do not change the setting of the bearings. But most single nuts require substantial machine work and are expensive to manufacture. Moreover they do not secure the nut as firmly as required in some applications. Sometimes they remain loose on the external thread, and this subjects them to vibration damage.
The present invention resides in a locking nut which, when secured against rotation, does not change its position along an external thread such as the thread of a spindle or a shaft. As such the nut is ideally suited for setting tapered roller bearings mounted in opposition on a shaft or spindle. The nut in essence includes two rings and some type of fastening device, such as cap screws, for changing the relationship between the rings. When the cap screws are backed off, the nut will turn easily on the external thread. However, when the cap screws are tightened, they deform the secondary ring and in effect jam it with respect to the main ring. The invention also resides in a bearing arrangement including the nut, in the combination of the nut and an external thread, and in a method of manufacturing the nut.


A nonreciprocally coupled ferrimagnetic band reject and bandpass filter having passbands from 2-18 GHz and 6-18 GHz respectively. The band reject filter comprises one or more ferrimagnetic spheres shielded from each other by placement in nonmagnetic, electrically conductive cavities in a block placed in the flux gap of a tuning magnet. Nonreciprocal coupling is achieved by using full RF coupling loops and establishing all factors that affect the transmission line delay for travel of signals from one point in the filter to another such as loop length and size, cavity size, sphere size and spacing, dielectric constant, RF coupling loop wire size and spacing etc. such that the effective electrical length from the center of one full RF coupling loop to the centerline of the neighboring RF coupling loop is 1/4 wavelength, i.e., an electrical phase change of 90 degrees occurs, and by placing the ferrimagnetic spheres outside the planes of their respective RF coupling loops to minimize the effect of (2,2,0) Walker modes. A ferrimagnetic passband filter comprises at least an input ferrimagnetic sphere in a cavity and an output ferrimagnetic sphere in a cavity in a nonmagnetic, conductive block located in the flux gap of a tuning magnet. Both the input and output spheres are coupled to full RF coupling loops coupling an RF input and an RF output, respectively, to the ferrimagnetic spheres and to ground. The effective electrical length between the RF input or RF output and ground through the respective RF coupling loops is 1/4 wavelength. Coupling is set tight to achieve wide bandwidth. The ferrimagnetic spheres are offset from the plane of the loop to achieve nonreciprocal coupling thereby allowing the (2,2,0) Walker mode spurious responses to be eliminated from the tunable passband.

The invention pertains generally to the field of filters useful in the 2 to 18 Gigahertz (hereafter GHz) range, and, more particularly, to tunable band reject and bandpass filters using yttrium-iron-garnet (hereafter YIG) ferrimagnetic tuning spheres.
In high frequency receiver systems operating in electrically noisy or hostile environments, it is often useful to have "wide-open" receiver systems which can pick up signals throughout a large band of frequencies. Frequently in such wide-open receiver systems, undesired signals can appear in the band. The unwanted signals can create an annoying interference or render the receiver system inoperable by saturating the input amplifier stages thereby blinding the system to desired signals.
To reduce or eliminate the effects of these unwanted signals, a class of tunable high frequency notch filters grew up. The purpose of this type of filter is to reject energy in an electronically tunable band of frequencies which is typically 25-50 megahertz (hereafter MHz) wide. This reject or stop band has a center frequency which is ideally tunable throughout the range of frequencies for which the receiver system is designed.
Designing a tunable notch filter which has a deep, narrow notch that can be tuned over a broad bandwidth is a difficult challenge. Approaches which were tried and which failed in the 1978 time period were mechanically tuned notch filters and switched, fixed-frequency filters. The mechanical filters failed because of poor reliability, limited tuning range and high costs. The banks of switched, fixed-frequency filters failed for similar reasons.
In response to these shortcomings, a class of YIG tuned notch filters were developed. All YIG notch filters are basically comprised of a transmission line structure which carries the RF signal to be applied to the receiver input and several YIG spheres which are coupled to the transmission line by RF coupling loops at points along the length. Although many different species of these YIG filters exist, they all have certain common characteristics. Typically the YIG spheres are coupled to the transmission line by half or full loops which create radio frequency (RF) magnetic fields which engulf the spheres. The YIG spheres act like tuned circuits, i.e., an inductor connected to a capacitor. Tuned circuits have a resonance frequency at which the impedance of the tuned circuit changes drastically from the impedance at frequencies other than the resonance frequency. A tuned circuit with the inductor and capacitor connected in parallel has a combined impedance which peaks, i.e., reaches its highest value, at the resonance frequency. A series tuned circuit has the inductor connected in series with the capacitor. In these types of tuned circuits, the combined impedance reaches a minimum at the resonance frequency.
Typically, the YIG spheres of a tunable notch or band reject filter are used as both parallel tuned circuits in "series" with the transmission line and as series tuned circuits coupled in "shunt" to the transmission line. This is done in prior art YIG filters by connecting the RF coupling loops together by one-quarter wavelength transmission line sections usually in the form of 50-ohm stripline formed on a substrate. These one-quarter wavelength sections are used as impedance transformers to effectively convert the electrical equivalent circuit of every other YIG sphere from a series-connected, parallel tuned circuit to a shunt-connected, series tuned circuit. The overall electrical equivalent circuit for the resulting YIG tuned notch filter is then a series of series-connected parallel tuned circuits separated by a number of shunt-connected series tuned circuits.
The resonance frequencies of all the tuned circuits in the above-described structure are all at the same frequency because all the YIG spheres are typically subjected to the same D.C. bias tuning magnetic field. That is, in this prior art structure, all the YIG spheres are typically placed in the same magnetic gap between two magnetic pole pieces. These magnetic pole pieces typically have coils of wire wrapped around them that carry a D.C. bias current. This current creates a steady magnetic field which is designed to be uniform throughout the gap between the magnetic pole pieces. This magnetic field envelopes the YIG spheres and magnetically biases each YIG sphere to have the same electrical resonance frequency. By changing the amount of D.C. bias current flowing through the magnet coils, the resonance frequencies of all the YIG spheres can be simultaneously tuned to the same, selected center frequency where the notch is desired.
The effect this has on the wide spectrum of RF frequencies passing through the YIG, notch filter (hereafter the passband) is to "cut a notch" in the passband. This notch is caused mainly by a high mismatch at the resonance frequency, i.e., the notch center frequency of the series-connected, parallel tuned circuit which reflects RF by virtue of being an "open circuit" in which no energy can pass and the low impedance to ground of the shunt-connected, series tuned circuit which reflects RF by virtue of being a short circuit through which no energy passes. That is, for a relatively small (typically 25-50 MHz wide) notch band, centered about the resonant frequency of the YIG spheres, the YIG spheres attenuate RF signals such that substantially less RF energy having frequencies in the notch band leave the YIG filter than entered it.
FIG. 1 is a block diagram of a typical prior art YIG stopband or notch filter application and FIG. 2 is a graph of YIG notch filter performance which illustrates the above-described phenomenon. In FIG. 1, an antenna 10 captures RF energy over a wide band of frequencies, say, for example, 2-18 GHz. This RF energy is guided to the input 11 of a YIG notch filter 12 which has a tunable center frequency for its stopband. This tunable notch or stopband is shown at 14 in FIG. 2. The vertical axis in FIG. 2 represents the attenuation loss imposed by the YIG filter on RF energy having the frequencies covered by the horizontal axis. The downward direction along the vertical axis represents increasing attenuation. RF energy in the stopband 14 at input 11 is reflected back toward the antenna or absorbed by the losses in the filter.
The resulting filtered RF energy, now lacking the RF signals that were within the stopband 14, is then guided to the input of a wide-open type receiver system symbolized by block 16. The receiver then outputs appropriate signals for use by a user via a user interface 18.
In FIG. 2, the frequency range from point 20 to point 22 represents the range of frequencies called the passband which the receiver 16 can detect. Assume now that an interfering signal at frequency F is detected and it is desirable to remove it. In such a case, a tuning command may be issued on line 24 either from the receiver 16 (such receivers typically have alarm circuits which help detect interfering signals) or from the user interface 18. This tuning signal will alter the level of D.C. bias current flowing through the magnet coils in the YIG filter 12 until the center frequency F.sub.c of the notch 14 is shifted so as to match the frequency (or center frequency) F or the interfering signal. The attenuation in the stopband of notch 14 then removes the interfering signal from the spectrum of RF energy which appears at the input of the receiver.
FIG. 3 represents the electrical equivalent circuit of the YIG notch filter. The equivalent circuit of FIG. 3 represents a three sphere YIG notch filter. Assume that the spheres are numbered 1 through 3 in order from the RF input 26 to the RF output 28. YIG spheres 1 and 3 have the series-connected, parallel tuned circuit equivalent circuit shown generally at 30 and 32, respectively. YIG spheres 1 and 3 are each connected to YIG sphere 2 in prior art YIG filters by one-quarter wavelength transmission line sections symbolized by lines 34 and 36. These sections convert the equivalent circuit of sphere 2, also shown as a parallel-tuned circuit, to a shunt-connected, series tuned circuit 38. If the YIG spheres were to be removed, the tuned circuits would disappear from the equivalent circuit of FIG. 3, and the resulting equivalent circuit would be a straight through transmission line coupling the input 26 to the output 28.
Typically, the antenna 10 and the input of the receiver 16 in FIG. 1 are designed to have a characteristic impedance Z.sub.0 of 50 ohms, which is an industry compatibility standard. It is axiomatic in electrical engineering that to maximize the efficiency of power transfer from the antenna to the receiver, one must match the output impedance of the antenna to the input impedance of the receiver. Likewise, where a YIG filter is placed between the input of the receiver and the antenna, to maximize the efficiency of power transfer from the antenna to the receiver, it is necessary that the YIG filter have an input impedance that matches the output impedance of the antenna and an output impedance which matches the input impedance of the receiver. If the input impedance of the YIG filter at 11 in FIG. 1, does not match the output impedance of the antenna (or the intervening transmission line), RF power is reflected back toward the antenna thereby creating a voltage standing wave in transmission line 40. The voltage standing wave ratio or VSWR is a measure of the degree of impedance mismatch.
The graph of FIG. 2, shows several small notches at 42 and 44. These notches are undesirable side effects called spurious responses or modes which are intrinsic to the use of YIG spheres. The most troublesome spurious response is the (2,2,0) Walker mode (also referred to herein as the 220 mode or 220 spurious response). It is desirable to eliminate these spurious responses.
It is also important for the YIG filter to attenuate the passband RF energy at frequencies on either side of the notch as little as possible. Any undesired attenuation is called insertion loss.
Thus, a good YIG notch filter will have the following characteristics: 1) a good impedance match with the devices coupled to its input and output, i.e., low VSWR, 2) low insertion loss, 3) minimal spurious responses, 4) deep notches of 25 to 50 MHz bandwidth, with a high Q factor, 5) agile, fast notch tuning throughout the passband, 6) predictable stopband characteristics, 7) a wide passband wherein the above stated characteristics remain within an acceptable range throughout the passband.
Workers in the art have been trying to achieve all of the above characteristics in a single design that covers a 2-18 GHz passband for many years. Several major problems exist which make achievement of all the above objectives over a passband of 2-18 GHz very difficult.
First, the physical length of the one-quarter wavelength impedance inverter is only correct at one frequency in the passband. At other frequencies, the inverters are not one-quarter wavelength long so the desired 90.degree. phase shift of a true one-quarter wavelength is not achieved exactly. Further, the one-quarter wavelength striplines impose increased insertion loss because of their non-air dielectrics.
Second, the bandwidth of the stopband or notch is dependent upon the loop coupling, with greater coupling giving a wider notch which is considered desirable by workers skilled in this art. Generally, full loop coupling where the YIG spheres are surrounded by full loops as opposed to half loops gives a wider notch.
Full loop coupling also has two other advantages which make its use throughout the notch tuning range highly desirable. First, full loop coupling is not nearly as sensitive to manufacturing errors in positioning of the sphere within the coupling loop. Second, full loop coupling does not generate as many spurious responses. With half loop coupling, a small positioning error in positioning of the YIG sphere within the half loop leads to a substantial change in the overall coupling. Full loops do not suffer from this problem since a positioning error leads to tighter coupling between the YIG sphere and one portion of the loop and looser coupling between the sphere and another part of the loop opposite the part of the loop with tighter coupling. The overall coupling remains approximately the same as it would have been absent the positioning error. Fewer spurious responses result from full loop coupling, because this type of coupling is more symmetrical than half-loop coupling. Spurious responses are generally caused by asymmetrical coupling.
The problem with full loop coupling is that the full loops have more inductance than half loops and this extra inductance is too high to be effectively compensated by shunt capacitance at the high end of the passband. The inductance of the coupling loops periodically loads down the transmission line throughout structure of the YIG notch filter at the locations of the YIG spheres and therefore affects the passband by dominating the characteristic impedance of the transmission line from the YIG filter RF input to its RF output, The characteristic impedance of a transmission line is: EQU Z.sub.0 =.sqroot.LC
where,
Z.sub.0 =the characteristic impedance per unit length, i.e., per section PA1 L=the inductance per unit length PA1 C=the capacitance per unit length.
Inductive reactance varies directly with frequency. Thus the reactance of a coil of wire increases as the RF frequency feeding the coil increases. This is the reason all attempts in the prior art to use full loop coupling at the 18 GHz end of the passband have failed until now. At these high frequencies, the inductance of the full loop coupling coils was so high that it was impossible to add enough capacitance per section to hold the characteristic impedance down to the industry standard 50 ohms over a wide range of frequencies. The impedance mismatch resulted in part of the desired RF energy in the passband outside the notch being reflected back toward the antenna. This caused an unacceptably high VSWR value.
As a result, in the prior art, different filter structures were used for different frequency ranges. In the early years of YIG filter design, YIG notch filters with full loop coupling were designed to operate in the range from 2-4 GHz. Another design was used for the range from 4-8 GHz and another design was used for the range from 8-18 GHz generally employing only half loop RF coupling. Generally, the length of the one-quarter wavelength sections was made smaller for the higher frequency designs and the coupling was changed from full loop at the low frequencies to half loop at the higher frequencies. It was necessary to shorten the one-quarter wavelength sections at the higher frequency to avoid the distortion in the notch shape which would otherwise result. The switch to half loop coupling at the high frequencies was necessary to keep the input and output impedances of the YIG filter near 50 ohms, but it also resulted in greater spurious responses.
Eventually, workers in the art determined that since the use of more YIG spheres gave a deeper notch, it was possible to stretch the design of a YIG filter such that one or possibly two designs could be used to cover the whole passband from 2-18 GHz simply by using more spheres. Thus, even though the performance steadily degraded at the lower frequencies, useable performance levels could still be obtained. That is, performance which was adequate to meet the specifications of customers was obtainable since more than enough notch attenuation and stopband bandwidth at the high frequencies was available and the degradation at lower frequencies was not enough to take the performance out of the acceptable range. However, none of these designs in the prior art were capable of using full loop coupling at the high frequency end of the passband, because of VSWR problems caused by the increasing inductive reactance of the full loops at high frequencies. As a result, to date no designer of YIG filters has been able to use full loop coupling to the YIG spheres in the high end of the passband near 18 GHz.
A short history of the various specific approaches that have been tried in the prior art is in order so as to better frame the subject and provide greater appreciation for the differences over the prior art of the approach taught herein according to the teachings of the invention. In 1978, the state of YIG filter design was generally as taught by W. J. Keane in his article "Narrow-Band YIG Filters Aid Wide-Open Receivers", published in Microwaves in September 1978 at page. 50 which is hereby incorporated by reference. In that article, basic YIG filter designs are discussed as are the various requirements for a good YIG filter design. The concepts of shunt capacitors to control Z.sub.0 and VSWR considerations and insertion loss and the desirability of linear phase characteristics throughout the passband are discussed. Also discussed are the relationship between spurious responses and tighter coupling. The tradeoffs between passband and stopband performance are discussed. The distortion in the shape of the notch as it is tuned over the passband caused by non-optimum resonator spacing is also discussed. This article states that the passband design fixes the stopband performance since the size, shape and spacing of the coupling loops that are matched in the transmission line determine the amount of coupling bandwidth achievable with a given size and number of spherical YIG resonators. The article goes on to state that the generation of spurious modes due to nonlinear RF fields in the YIG resonators ultimately limits the minimum sphere-to-loop spacing. This statement assumes that half loop coupling is used, and there is no suggestion that full loop coupling can be used. In fact, this article suggests that since passband performance is paramount, full loop coupling cannot be used at high frequencies since it would cause high VSWR and large insertion losses which would be very disadvantageous. The maximum tuning range without excessive notch shape degradation is suggested to be two octaves.
The state of the art of prior art, full loop YIG notch filter design prior to the invention is probably best understood by referring jointly to FIGS. 4A, 4B and 4C. These figures show a 4-sphere YIG notch filter design using full coupling loops and designed for use in a 2-6 GHz passband. Although frequently 6 to 8 YIG spheres would be used in conventional designs, only 4 spheres are shown here for simplicity. FIG. 4A shows a plan view of the YIG notch filter while FIG. 4B shows an elevation view and FIG. 4C shows the filter in pseudo-schematic form. In this prior art design, the YIG spheres 46, 48, 50 and 52 are supported in a magnet air gap 54 between two circular cross section electromagnet pole pieces 56 and 58 by beryllium oxide support rods 60, 62, 64 and 66 which are anchored in heater blocks (not shown). The pole pieces have wound around them D.C. bias electromagnet coils 68 by which a D.C. magnetic field is created in air gap 54. In the prior art designs symbolized by FIGS. 4A through 4C, the pole pieces 56 and 58 were separated by an air gap which was approximately 0.060 inches across. By changing the intensity of the D.C. magnetic field in this air gap, the resonance frequency of all of the YIG spheres could be simultaneously tuned thereby altering the center frequency of the band reject notch.
The YIG spheres used in prior art designs generally used spheres which were 0.015 to 0.030 inches in diameter. In addition, between each sphere, a 50 ohm microstrip or strip line transmission line was used as an impedance inverter. These microstrip or stripline impedance inverters are symbolized in FIG. 4A by the line between solder joints 71 and 73, the line between solder joints 75 and 77, and by the line between solder joints 79 and 81. The 50 ohm transmission line impedance inverters were fabricated on an insulating substrate (not air) and were designed to be 1/4 wavelength at some frequency in the desired passband.
Because the impedance of the full coupling loops became very high at 18 GHz, it was impossible in the prior art designs symbolized by FIGS. 4A-4C to match the overall impedance of the coupling structure to the 50 ohm line at the RF input 78 and the RF output 83. The resulting impedance mismatch caused major VSWR problems and higher insertion loss. For these reasons, the full loop designs were not used at 18 GHz. At these higher frequencies, 1/2 loop coupling straps were used in the prior art as symbolized by FIG. 5 instead of insulated wire. The 1/2 loops cut down on the available coupling, and caused more spurious modes. Further, they were sensitive to manufacturing errors in placement of the spheres in the centers of their cavities. However, the half loops were easier to match to 50 ohms, because their impedance was less at 18 GHz, and they had proportionally more surface area to capacitively couple to the cavity walls to provide the shunt capacitance C in equation (1) above. Additional capacitive coupling between the coupling loops and the ground plane was provided by grounded, adjustable shim plates of which plates 88 and 90 were typical. These shim plates generally were used to cover the tops of the cavities formed in a metal block like block 89 in FIG. 4B suspended in the air gap 54 which contained the YIG spheres. Capacitive coupling to adjust impedance and VSWR was altered by deforming the shims to push them closer to or further away from the RF coupling loops. Also, the cavities in the prior art designs, of which cavity 91 in FIG. 4B is typical, were spaced much further apart in the prior art designs than the spacing according to the teachings of the invention and were arranged in a circle. Only the cavities of the spheres 46 and 52 of FIG. 4A are visible in the cross section of FIG. 4B with the cavities of the spheres 48 and 50 obscured behind.
The YIG notch filter according to the teachings of the invention is aligned to match all center frequencies of the YIG spheres as closely as possible by rotating all the spheres in their cavities until best performance is achieved.
The structures of FIG. 4A and 5 are the structures upon which the article by W. J. Keane cited above was based. For the high frequency part of the desired passband from 6-18 GHz (typically), the prior art half loop structure FIG. 5 would be used with all other structural details being the same except that sometimes coupling straps were used instead of wires. Since the half loops 80, 82, 84 and 86 have substantially less inductance at the high frequency end of the passband, it is possible to add enough shunt capacitance via shim plates 88, 90 92, 94, 96, 98, 100 and 102 to keep Z.sub.0 down to close enough to 50 ohms to result in an acceptable VSWR.
In December of 1979, U.S. Pat. No. 4,179,674 (hereafter the '674 patent) to Keane et al. issued which is hereby incorporated by reference. This patent taught a RF coupling structure for non-reciprocal coupling using half loops and a cover over the YIG spheres to increase the shunt capacitance between the coupling loop and the groundplane. This shunt capacitor produced a phase shift which caused circular or elliptical polarization and was thought to increase the Q from the 100 to 500 values previously achieved to the 20,000 range for both the VHF and microwave ranges. The '674 patent also teaches dividing the RF coupling loop up into two coupling loops which couple to the YIG sphere in a spatially orthogonal fashion with phase orthogonality produced by a divider circuit to produce circular polarization. The '674 patent teaches linear polarization as yielding an absorptive filter. This patent also teaches offsetting the YIG spheres from the plane of the RF coupling loops to generate circular polarization and coupling a shunt capacitor to one of the electrical transmission lines to introduce a 90.degree. electrical phase shift and circular polarization. The '674 patent teaches that by offsetting the YIG sphere and using circular polarization reduces spurious responses. The '674 patent also teaches that offsetting without circular polarization has the opposite effect in producing more spurious responses. The patent also teaches that the sense of the polarization is important in eliminating spurious responses. This depends upon the sense of the static magnetic field, and the side of the loop to which the sphere is offset. A single line YIG sphere offset and a capacitor coupled to the middle of the loop is also taught in FIG. 10 to achieve single line. An adjustable shim casing to vary the shunt capacitance is also taught.
In August 1980, U.S. Pat. No. 4,216,447 to Keane et al. was issued which contained the same teachings as U.S. Pat. No. 4,179,674, but which claims different subject matter.
In January of 1981, U.S. Pat. No. 4,247,837 issued to Mezak, et al. (hereafter the '837 patent) which is hereby incorporated by reference. This patent teaches using multiple conductors in the coupling loop to increase the coupling to the YIG spheres. The multiple conductors of the coupling loop are separated by at least one diameter and are taught to be a superior approach in attempting to get notch bandwidth greater than 35 MHz. Prior approaches to increase the notch bandwidth included bringing the coupling loop closer to the sphere and using a lower inductance conductive strap as opposed to a single wire loop. Both of those prior approaches are taught to have increased "crossing" and "tracking" spurious responses. "Tracking" spurious responses are unwanted spurious mode notches that move with the center frequency of the desired notch. Crossing spurious responses move at rates different than the center frequency of the desired notch. The '837 patent teaches the conventional wisdom that prior attempts to increase the notch bandwidth by increasing the turns in the coupling loop did not work and, therefore, teaches away from the invention. This was because of the increased series inductance in the line from the input to the output which lowered the frequency of the high frequency cutoff end of the passband above which the filter was useless. The '837 patent also teaches that prior attempts to solve this problem included use of a strap and multiple closely spaced or touching wires in the coupling loop both of which approaches have failed because of increased spurious responses.
Significantly, the '837 patent, at Col. 2, lines 2-8 and Col. 6, lines 3-19, teaches that it is disadvantageous to increase the number of turns of the coupling loops because it increases the series inductance in the line between the input and output ports. The '837 patent teaches that use of multiple, separated conductors works better than large diameter wires or straps because less spurious modes are created. The multiple conductors of the '837 patent are used in RF coupling loops only and are not used in the transmission line segments between coupling loops.
In 1986, Watkins-Johnson announced, in the April issue of Microwave Journal, an 8-stage, YIG-tuned notch filter with a 60 MHz notch bandwidth and a 6-12 GHz passband. This filter had tracking spurious responses of 4 db (maximum) and a VSWR of 2:1 (maximum). Passband insertion loss was 1 db (maximum). Subsequently, Watkins-Johnson announced, by data sheet, a series of 8-stage, YIG-tuned notch filters that cover various segments of the passband from 0.5 to 26 GHz. Notch bandwidth varied from 5 to 35 MHz with 40 db of rejection and VSWR values ranged from 1.5:1 to 2:1 and insertion loss values ranged from 1 to 2 db. Tracking spurious modes were 4 db maximum.
In April 1989, the then existing state of the prior art in YIG-tuned notch filter design was summarized by W. J. Keane in a design note that was widely circulated to customers for YIG filters. This design note discussed the relative merits of 4-sphere vs. 7-sphere YIG filters and the theoretical tradeoff between band-reject and passband performance. This design note is included herewith as Appendix A.
In this design note, the effect of the fraction of coupling turns of the RF coupling loop on the notch bandwidth is discussed at page 11. There, four different approaches in the prior art are identified for designing the passband for a YIG notch filter. The first approach is to design a loop whose impedance is nominally 50 ohms over its entire length. In this approach, the YIG spheres are placed in cavities with the coupling loops in the cavities positioned between the cavity walls and the sphere. The coupling loops are connected by impedance inverters in the form of 90.degree. lengths of stripline transmission line. The disadvantages of this approach is that it needs a sizeable area to accommodate all the cavities and striplines. This makes the magnet gap large in area and renders it more difficult to achieve equal magnetic flux intensity for all spheres. Large gaps also make rapid tuning of the notch center frequency more difficult since large amounts of magnetic flux need to be changed in flux density level to tune the center frequency. It is believed that Watkins-Johnson uses this approach.
The second prior art approach discussed in the Keane design note is a stripline circuit where the loop inductance is matched using distributed capacitance on both sides of the cavity. However, for large fractional coupling loops, it is difficult to achieve sufficient capacitance to make the match at the high frequency end of the passband. Another disadvantage of this second approach is the fact that the cavities and impedance inverters are not totally shielded, making it difficult to provide isolation between the input and output. This approach could be used at lower frequencies to match a single or multiple turn coupling loop.
The third approach is an iterative matching procedure consisting of a single transmission wire that is periodically loaded by the RF cavity walls. One advantage of this approach is high fractional coupling factor including full or multiple full turn loops. This increases the notch bandwidth and reduces coupling into magnetostatic modes such as the 210 mode. Also, nonreciprocal coupling can be used to suppress several other modes. This approach requires less area for the RF magnet gap and the RF circuit. The insertion loss and VSWR for this approach can be very good depending upon the passband. However, at the time this third approach was developed, the use of the full loop coupling was contemplated only for low frequencies where it was possible to match the line impedance using the casing. The Ferretec design criteria note acknowledges this conventional wisdom at page 15 indicating that designs of the day were generally intended for either a low band of 2-6 GHz or a high band from 6-18 GHz.
The fourth approach consisted of designing a low pass filter structure which combined distributed loop coupling and discrete inter-loop capacitors. This approach is practical for broadband designs only at low frequencies. However, the fractional coupling factor n cannot be as large as with the iterative matching approach. This approach has been used primarily in the low passband range.
In February 1985, the assignee of the present invention made and sold to Watkins-Johnson a YIG notch filter according to the third approach but using a pair of wires to form both the coupling loops and the inter-connecting transmission line segments rather than a single wire. Four YIG spheres and 1/2 coupling loops were used. Band reject performance was unsatisfactory from 2-16 GHz until the twin wires were soldered together at the midpoint between the spheres 2 and 3. This changed the coupling from "unusual" at 10 and 20 GHz to "normal" at 10 GHz and unusual at 20 GHz. Subsequently, three solder joints were used, one between each loop at the midpoints of the connecting segments. This caused the structure to have normal coupling from 4-26 GHz and behave like a single loop. The notch appeared most symmetric at 14.5 GHz.
Changing the wire diameter from 0.003 inches to 0.0075 inches with three solder joints improved the performance further.
A variant was then tried with the outer sphere 1 and 4 coupled by half loops and the inner spheres coupled by full loops. In this embodiment, the cavity diameter was 0.060 inches and the air gap was 0.060 inches using 0.018 inch diameter YIG spheres. Solder joints were only used at the midpoints of the transitions between the half loops and the full loops. The performance of this combination deteriorated significantly in that the insertion loss climbed from less than 1 dB to greater than 6 dB at 13 GHz. Return loss went from less than 10 dB to approximately 0 dB. This failure further confirmed the Ferretec belief in the conventional wisdom that full loop coupling can only be used in the low frequency end of the passband and was another signpost pointing away from the path which eventually resulted in finding the invention.
The Ferretec structure with half-loop coupling and solder joints between loops was shipped in 1985.
In July of 1990 Watkins-Johnson announced a 10-stage band reject filter in Microwave Engineering Europe. This device used a larger number of YIG spheres than had been previously tried. A family of filters built around this concept eventually resulted including filters which cover passbands from 6-18 GHz, from 12-18 GHz and from 6-12 GHz. 40 dB notches with 25 MHz notch width for the passband from 6-18 GHz is available with this family of filters and 40-50 MHz notches for 6-12 and 12-18 GHz is also available.
In all the prior art described above, full coupling loops have never been successfully used in the higher end of the frequency range. Further, it has often been assumed in prior art approaches that a circular configuration of the YIG spheres was necessary so that all spheres would experience the same magnetic field intensity even though the circular configuration is not the most efficient configuration in terms of air gap area required. Probably the biggest problem facing YIG filter designers over the years has been how to handle the spurious (2,2,0) Walker mode. When a YIG sphere resonates, it has a useful 110 mode which can be used to create either a bandpass or band reject filter as described in the '674 patent discussed above. However, the YIG sphere also resonates at harmonic frequencies and these resonances create irksome spurious modes or "spurs" that create unwanted notches in the passband. The '674 patent teaches that nonreciprocal coupling can be used to reduce or eliminate the 220 spurious mode, but it also teaches that the nonreciprocal coupling is generated by the use of circular polarization. The circular polarization is achieved by offsetting the YIG spheres from the plane of the coupling loop to provide spatial orthogonality and coupling a shunt capacitor to the coupling loop to provide a 90 degree phase shift.
Unfortunately, the achievement of circular or elliptical polarization is difficult and unpredictable, and all the ways of doing it taught in the '674 patent were so complicated that nobody in the industry adopted these teachings.
Therefore, a need has arisen for a simple YIG notch filter and bandpass filter design that uses full loop coupling both at the high and low frequencies, and which need not necessarily have the YIG spheres arranged in a circular configuration, and which can achieve nonreciprocal coupling in a predictable manner so as to minimize the effects of the (2,2,0) Walker mode.

Yig tuned high performance filters using full loop, nonreciprocal coupling


A method of estimating a basepoint includes receiving a plurality of goals, wherein each goal has a desired value, and receiving a plurality of sensor feedback signals from a controlled system. A plurality of predicted output values of the controlled system are received from a mathematical model. A desired change for a plurality of basepoint values is estimated in response to the goals, the feedback, and the predicted output values. An actual change in basepoint values is calculated in response to a plurality of limits and the desired change for the plurality of basepoint values according to a plurality of goal weights while holding limits. The actual change in basepoint values is combined with last pass values of the plurality of basepoint values to produce an updated basepoint estimate.

This application relates to control systems, and more particularly to a method of estimating a basepoint in a multivariable control system according to a relative goal prioritization scheme.
In control theory, a given control system may have a plurality of goals and a plurality of limits. Limits are inequality constraints on system dynamic variables. An example limit may be to prevent an engine temperature from exceeding a certain temperature to prevent engine deterioration. An example goal may be to achieve a certain engine thrust level, such as a thrust of 10,000 pounds. While it is desirable to achieve goals, it is necessary to meet limits.
A multivariable system may include a number of effectors that can be adjusted to meet system goals and limits. In some cases, a system may be cross-coupled, which means that each effector change may affect goals and limits with varying dynamics. In a cross-coupled system, it may not be possible to change a single effector in isolation to affect a single goal or limit, as a change in one effector may affect a plurality of goals or limits.
A basepoint is a set of system values corresponding to a state of equilibrium in which a rate of change for the system is zero, a predetermined amount of limits are met, and a quantity of goals are fulfilled.

This patent is subject to a terminal disclaimer.


Embodiments of the present disclosure provide a cell access method, an apparatus, and a system, where the method includes: when user equipment camps on a first cell, receiving, by the user equipment, a first signal offset of the first cell and a random access failure threshold of the first cell; attempting, by the user equipment, to perform random access to the first cell, and counting a quantity of random access failures; and if the quantity of random access failures reaches the random access failure threshold, performing cell reselection, by the user equipment, by using the first signal offset for the first cell; and if no cell meets a service condition in cell reselection, performing cell reselection, by the user equipment, without using the first signal offset. Therefore, a service interruption problem of user equipment when random access to a cell fails in the prior art can be resolved.

In a wireless communications system, after being powered on, user equipment (UE) selects a suitable cell to camp on, then establishes a connection to a base station of the cell by performing a random access process, and performs a registration process, a location update process, and other processes.
After camping on a cell, the UE selects, according to changes of a location after movement, a base station of a cell, and a service and the like, a better serving cell to camp on by means of cell reselection, for example, a serving cell having better signal quality or a higher priority.
In practical application, due to a geographical environment, weather, or the like, it occurs that a base station located far from a UE can provide, a better downlink signal than a base station located near the UE, but cannot normally receive an uplink signal that is sent by the user equipment during random access, which causes that when selecting a cell to camp on, the UE selects a cell in which the base station located far from the UE is located, and the random access performed by the UE fails, leading to interruption of a service provided to the UE. Because this special situation occurs in the Chiba region in Japan, such a cell is referred to as a Chiba (CHIBA) cell. FIG. 1 is a schematic diagram of a Chiba cell in the prior art. As shown in FIG. 1, due to a reflection action of the surface of a lake, a UE receives a downlink signal of a cell A on the right of the lake better than a downlink signal of a cell B on the left of the lake, and therefore the UE selects the cell A to camp on. However, because the UE is located far from the cell A, a failure occurs when the UE initiates random access; and even though the UE successfully performs random access to the cell B, the UE still reselects the cell A due to a better downlink signal of the cell A, causing service interruption.

Cell access method, apparatus, and system


A transport facility includes a track, and first and second transport vehicles that travel along the track. In order to supply electric power to the transport vehicles, a flexible first cable guide which includes a front-end attached to the first vehicle and a base-end fixed to the track, is folded back in a U-shape between the base-end and the front-end, is provided on a first side of the track, and supplies electric power to the first vehicle, and a flexible second cable guide which includes a front-end attached to the second vehicle and a base-end fixed to the track, is folded back in a U-shape between the base-end and the front-end, is provided on a second side of the track, and supplies electric power to the second vehicle. Thus, the first and second flexible cable guides are compactly installed while preventing interference therebetween.

1. Field of the Invention
The present invention relates to a transport facility for use in an automated warehouse and the like, and particularly relates to supplying electric power to the transport vehicle.
2. Description of the Related Art
An automated warehouse in which two transport vehicles travel on the same track is known (JP 2007-1692). In such an automated warehouse, racks are divided into a common area to which the two transport vehicles access, and dedicated areas to which only one transport vehicle accesses. The transport vehicles are controlled so as to be prevented from interfering with each other in the common area.
Meanwhile, when electric power is supplied to the transport vehicles via cable guides, interference between the cable guides becomes a problem. On the other hand, a cable guide is a member having a large width, and needs a large space in order to be installed. Therefore, it is necessary to make it possible to compactly install a pair of cable guides while preventing the interference between the cable guides.

Transport facility and automated warehouse


The disclosed invention is an innovative, cost-efficient driving mechanism for the prosthetic hand industry that makes the use of only one motor to individually control each digit on a prosthetic hand separately. The use of the novel electromagnetic actuation system, locking mechanism, and spline nut and shaft configuration coupled with the single motor greatly reduces the weight, size and power usage of the prosthetic, increases functionality, minimizes noise, increases and speeds and forces, and orients the parts of the device in a manner that creates an aesthetically appealing design.

The need for and use of prosthetic hands has been around for centuries. Even today with advancing technologies, the use of the inefficient prosthetic devices is critical as several thousands of people in the United States alone have entire arm amputations and partial/complete hand amputations. After the loss of a limb, a significant part of a patient's recovery and resumption of daily activities is dependent upon the use of a prosthetic device. This recovery becomes more complex when the loss is of an entire hand. In the last twenty years, the prosthetics design and technology has seen major improvements, allowing for more functionality and increased dexterity for upper limp amputees. However, still, there are major needs that can be addressed to further the advancement of prosthetic hand designs to allow prosthetic hand users to have capabilities similar to those of an innate human hand.
Despite attempts to mimic the natural mechanisms of the hand, existing hand models lack dexterity and functionality and are underactuated, bulky, and expensive. The current art does not focus on these shortcomings of the prosthetic itself, but rather on improving the technology used to control prosthetic hand devices. This involves applications that are centered on Brain Computer Interfaces (BCI), signal processing, and feedback control mechanisms. These applications create an interface between the amputee and the prosthetic device and allow users to apply various forces and different grasps that are needed in everyday activities via electromyography technology. These "myoelectric" prosthetic hands use sensors strategically placed on the residual limb to detect muscle contractions that translate into finger movements of the hand. Myoelectric designs that are currently on the market and are reflective of the current state of the art include the Vincent Hand by Vincent Systems, i-Limb Hand by Touch Bionics, i-Limb Pulse by Touch Bionics, BeBionic Hand by RSL Steeper, BeBionic Hand v2 by RSL Steeper, and the Michelangelo Hand by Otto Bock. However, more traditional body powered devices are more accepted than the newer myoelectric designs due to major technology gaps that exist to make these "myoelectric" hands more efficient and feasible for amputees to use.
Problems in the current art with current models include: (1) the weight of the prosthetic device; (2) the cosmetic appearance of the prosthetic; (3) the grasping forces and speeds presently in the art; (4) needed noise reduction; and (5) increased functionality. These "technology gaps" exist due to the difficulty of creating an artificial hand that closely mimics the innate abilities of the natural human hand while keeping the design parameters within reasonable confines of the hand's relative anatomical features (e.g., weight, size, and cosmetic appearance). Addressing all of the needs is challenging and can be generalized by improving the overall driving mechanism of the prosthetic device since the driving mechanism does encompass issues related to device weight, force, speed, noise, and overall functionality.
The driving mechanism of prosthetic hands manipulates the digits of the hand, individually or together, to allow the user to undertake various activities. Several deficiencies of currently available artificial hands relate to the driving mechanisms of these devices, so improving on the design of the mechanism can address these needs and can allow for greater manipulation and dexterity of the prosthetic device by the end user. Several driving mechanisms are currently used to operate prosthetic designs, and each uses a different technique to provide motion to the digits of the prosthetic device. These mechanisms can be classified into one of six categories: (1) body-driven; (2) pneumatic; (3) hydraulic; (4) cable transmission; (5) multiple transmissions; and (6) hybrid combinations.
Body-driven prosthetic devices for upper limb amputees consists of a body harness connected to a cable that leads to the end of the device where the cable is than usually connected to a 2 digit pinching mechanism. The apparatus can be opened or closed by moving the opposing shoulder unto which the harness is fastened. They are cheap, lightweight, durable, and easily assembled, but they have limited grasping capabilities, are awkward in appearance, and constrict the body when in use.
Pneumatic driving mechanisms use a fluid actuator element to provide motion to the digits of a prosthetic hand. These actuator elements contain several parts including a feed channel, fluid pump, and an air chamber that is connected to the movable joints of a prosthetic hand. When the elements are inflated with air, the volume of the elements expands and causes movement of the finger. Pneumatic designs are capable of being small and lightweight with comparable grasping forces to a human hand, but they require large amounts of power to operate and produce loud hissing sounds when in operation.
The hydraulic mechanism has the same advantages of the pneumatic mechanism with added qualities. The hydraulic mechanism uses fluid actuators, but it also contains a multi-valve micro pump with an attached fluid reservoir that allows fluid to be transferred to several elements to move several fingers at the same time. Movement is basically the same in both mechanisms with movement of device caused by the expansion of several actuator elements. The hydraulic mechanism has a lower energy consumption and greater grasping forces than the pneumatic design without the hissing sounds from the actuators. The mechanism has dual functions and can be operated with air or liquid, but weight issues and the potential of hydraulic fluids leaking from the elements causing detrimental damage to the electronic controls is too risky.
Cable transmission mechanisms consist of a combination of cables and pulleys located in the joints of the artificial fingers of the prosthetic hand. The pulleys are operated by servomotors that can turn the pulleys allowing movement of the fingers. These mechanisms are also considered to be lightweight and small with similar grasping forces compared to the hydraulic designs but have limited ability and maintenance issues due to the number of moving parts.
The multiple transmission mechanism is a hybrid mechanism that uses various approaches to provide motion to the fingers of the prosthetic device, and many driving mechanisms fall under this category. However, each mechanism contains but is not limited to a motor and actuator system that is linked to a gearbox which in turn rotates a driveshaft. They work in a manner similar to the cable transmission design but include a blocking system that locks pulleys in place to allow for a position to be held. This design allows for multiple pulleys to be operated by one motor, which can reduce the weight of the hand, but it also reduces the grasping force of the hand since each finger is coupled to the same motor.
The hybrid option is a mixture between the body-powered prosthesis and the externally powered driving mechanism. The most common combination is the use of a body-powered elbow with an electric hand or wrist or an electric elbow with a body-powered hand.
Each mechanism has its advantages and disadvantages depending on the individual user and the intended use of the device. Yet, major technology gaps exist that prevent a more efficient and complete mechanism to be implemented into a prosthetic hand to allow for individual manipulation of all 5 digits including automated thumb rotation. The new technology disclosed herein is an electromagnetic driving mechanism for a prosthetic hand device that fills the current technology gaps in the prosthetic hand industry.

Electromagnetic actuation mechanism for individual digit control of an artificial hand


A control apparatus for an internal combustion engine of this invention includes: a turbo-supercharger; an exhaust gas purifying catalyst disposed in an exhaust passage on the downstream side of a turbine; and a WGV capable of opening and closing an exhaust bypass passage that bypasses the turbine. At the time of a catalyst warm-up request, catalyst warm-up control that opens the WGV and retards the ignition timing is executed. If the sensitivity of control of an intake air amount by a throttle valve is high, the intake air amount is controlled using the throttle valve during execution of the catalyst warm-up control. If the control sensitivity is low, the intake air amount is controlled using the WGV during execution of the catalyst warm-up control. When the WGV degree of opening is controlled toward a closed side during execution of the intake air amount control using the WGV, a retard amount of the ignition timing is increased.

A control apparatus for an internal combustion engine which includes a turbo-supercharger and a waste gate valve that opens and closes an exhaust bypass passage that bypasses a turbine has already been disclosed in, for example, Patent Literature 1. According to the conventional control apparatus, a configuration is adopted so as to perform the following control to warm up an exhaust gas purifying catalyst that is disposed on the downstream side of the turbine after a cold startup. That is, when the internal combustion engine is in an idling state after a cold startup, the aforementioned control apparatus is configured so as to execute catalyst warm-up control (specifically, corresponds to "upstream catalyst warm-up process" in Patent Literature 1) that opens the waste gate valve and retards the ignition timing.
Meanwhile, the atmospheric pressure is low in a highland area. If the air density decreases accompanying a decrease in the atmospheric pressure, the torque that is generated by an internal combustion engine decreases. Consequently, in a highland area, it is necessary to enlarge the degree of opening of a throttle valve in order to secure an intake air amount (required intake air amount) that is required to maintain an idling speed during execution of the above described catalyst warm-up control. Consequently, a difference between the intake pressures before and after the throttle valve decreases. For this reason, in a highland area, in some cases it is difficult to perform adjustment of the aforementioned required intake air amount using the throttle valve while catalyst warm-up control is being executed.
Further, since the exhaust gas temperature rises when the ignition timing is retarded, the amount of exhaust energy that is introduced into the exhaust gas purifying catalyst can be increased. However, retarding the ignition timing leads to a decrease in the torque of the internal combustion engine. Accordingly, in a highland area, in a case where maintaining the idling speed is prioritized when it has become difficult to secure the required intake air amount using the throttle valve during execution of catalyst warm-up control, it is difficult to sufficiently retard the ignition timing. Consequently, it is difficult to maintain the amount of energy that is introduced to the exhaust gas purifying catalyst at a high level. Thus, with respect to the catalyst warm-up control disclosed in the aforementioned Patent Literature 1, there is a concern that in a highland area where the atmospheric pressure is low, a situation may arise in which an exhaust gas purifying catalyst cannot be warmed up sufficiently.
Including the above described document, the applicant is aware of the following documents as related art of the present invention.

Control apparatus for internal combustion engine


A reflector for use under a radome disposed on a mobile platform such as an aircraft for reflecting a portion of the electromagnetic energy radiated by an antenna disposed under the radome such that the reflected portion of energy impinges the radome at an angle normal thereto, thereby reducing or eliminating further reflections of the reflected portion of energy within the radome toward the mobile platform on which the radome is mounted. In one preferred embodiment the radome includes a base portion which is covered with a cover of radar absorbing material (RAM). In another embodiment the radome includes a curved base portion which is adapted to match the curvature of the surface of the mobile platform on which the reflector is mounted.

This invention relates to antenna assemblies, and more particularly to a reflector for use with an antenna disposed within a radome on a mobile platform such as an aircraft for reducing reflections of electromagnetic energy within the radome.
Antennas are now being used on the exterior surfaces of commercial aircraft to provide broadband interconnectivity with ground based stations via one or more satellite-based transponders. Such antennas are often electronically scanned phased array antennas, mechanically augmented phased array antennas, or other forms of reflector antennas which are disposed on an exterior surface of the fuselage of the aircraft. The antenna is typically mounted within a radome and radiates its beam through the radome when in a transmit mode of operation.
An undesirable consequence of mounting the phased array antenna within the radome is the creation of reflections of electromagnetic energy caused by the radiated electromagnetic energy impinging the radome at angles other than normal to the interior surface of the radome. However, when electromagnetic energy impinges the radome at an angle normal to the surface of the radome, the great majority of the energy passes through the radome. The problem with reflected energy is particularly acute when the main beam from the antenna is scanned at a scan angle of between about 30xc2x0-75xc2x0 from the boresight of the antenna, which causes the beam to be directed along an axis which is close to parallel to the exterior of the fuselage of the aircraft. At this scan angle, the electromagnetic energy impinges an interior surface of the radome which is tapering toward the fuselage. Electromagnetic energy impinges the interior surface at an angle which is not normal thereto, thus causing a significant degree of energy to be reflected by the interior surface of the radome back toward the aircraft. This situation is highly undesirable as such reflected energy can be directed into the skin of the aircraft, wherein the skin can act as an antenna to further radiate the energy towards other RF receivers or transceivers in the vicinity of the aircraft, and particularly transceivers located on the ground below the aircraft. Since the radome must have a highly aerodynamic shape, it becomes impossible to avoid the problem of reflections within the radome because at such angles as described above (i.e., about 30xc2x0-75xc2x0), the main beam radiated by the antenna will always be impinging the walls of the radome at angles that are not normal to the interior surface of the radome.
Accordingly, it would be highly desirable to provide some form of reflector within the radome which at least partially circumscribes the antenna to reflect a portion of the radiated electromagnetic energy from the antenna toward the interior surface of the radome such that the reflected electromagnetic energy impinges the interior surface of the radome at an angle normal thereto, thus minimizing the reflections that occur within the radome when the antenna is scanned to an angle greater than about 30xc2x0 off of its boresight.
It would also be highly desirable to provide such a reflector as described above that does not interfere with operation of the antenna, whether the antenna is an electronically scanned phased array antenna or a mechanically augmented phased array antenna, or other form of reflector antenna, and further which does not require modifications to the shape of the radome or necessitate non-aerodynamic modifications to the contour of the radome.
The present invention is directed to a reflector for use within a radome mounted on an exterior surface of a mobile platform. In the embodiment illustrated and described herein, the radome is adapted to be secured to an exterior surface of a commercial aircraft.
The reflector comprises a frustoconical member which is adapted to be mounted to the exterior surface of the mobile platform on which the radome is mounted. The reflector, in one preferred form, is circular and completely circumscribes the antenna. In a preferred embodiment the reflector also includes a base portion which forms a planar panel adapted to be disposed against or adjacent to the outer surface of the mobile platform on which the radome is mounted. The base portion can support the antenna directly thereon or can be used to support an intermediate component which itself is supporting the antenna. The reflector, as well as the base, is preferably manufactured from a thin metallic sheet and includes a layer of radar absorbing material (RAM) on an upper surface thereof. The reflector is formed such that it diverges from the outer surface of the mobile platform. The angle of divergence is dependent on the precise contour of the radome.
In the preferred embodiment, at least one independent reflecting plate is disposed on an exterior surface of the mobile platform outwardly of the reflector to further absorb reflected electromagnetic energy that would otherwise be directed by the interior surface of the radome back into the metallized skin of the mobile platform.
The angle of the reflector is further selected based on the contour of the radome, and further such that the reflector will intercept a portion of the main beam radiated from the antenna, when the main beam is scanned at an angle greater than about 30xc2x0 off of the boresight of the antenna, such that a portion of the radiated electromagnetic energy is reflected by the reflector plate towards the radome and impinges the radome at an angle normal to the interior surface of the radome. In this manner the great majority of the reflected electromagnetic energy from the reflector passes through the radome without the radome causing any further reflections thereof toward the mobile platform.
The reflector of the present invention can thus be used with a wide variety of antennas and does not require modifications to the aerodynamic shape of the radome, which is extremely important in maintaining a smooth aerodynamic profile for the radome.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Reflector assembly for minimizing reflections of electromagnetic energy from an antenna disposed within a radome


A method for the formation of an overcast seam by means of a zig-zag sewing machine. After the formation of the first looping of needle and looper thread in a first overstitch position of a needle bar the needle thread is loosened and the needle bar moves into a second overstitch position, in which a further thread looping takes place. After the formation of at least one straight stitch in the second overstitch position, the joining thread between the first two thread looping is drawn out, forming a loop in the first overstitch position, the needle pierces into the loop, after which it is released. The seam thus formed is a firm joining seam by which the sewing material is not gathered between the thread loopings. The method is carried out on a device which comprises an oversewing tongue to which is assigned, in order to obtain two successive motional phases, a starting handle arranged in the swinging path of the needle bar, and a starting handle arranged in the axial path of motion, for the first overstitch position and into whose path of motion protrudes a loop stripper. The needle bar thus controls the drawing out and casting off of the joining thread between the first two thread loopings.

The present invention relates in general to sewing machines and, in particular to a new and useful method and device for forming overcast seams using a standard zig-zag sewing machine.
From German OS No. 28 11 455 is known a method for the formation of a seam that can be used as an edge finishing seam on a zig-zag sewing machine, according to which the third of three forward stitches is made by changing the lateral stitching position. The first of the four forward stitches is made by changing the stitch position, and the following two are made in this stitch position. The fourth is made again by changing the stitch positon, and so on whereby the stitches spaced from the cloth edge are sewn by reversing the direction of feed. In this way needle and bobbin thread are formed concatenated at each penetration of the needle, both on the outer edge of the cloth and at a distance thereof, hence in both overstitch positions of the needle. All overstitches are made in the direction of feed.
Since this seam is only formed by controlling the overstitch movements of the needle and the feeding movements of the cloth feed, so that it is a pure zig-zag seam, it has the inconvenience inherent in all known zig-zag seams namely, that it must be sewn with a much lower tension of needle and bobbin thread than a straight seam, in order to keep the unavoidable unsightly gathering of the seam, and thus of the sewing material at a minimum, which is particularly conspicuous in the production of an edge finishing seam. But this cannot be completely avoided in the production of a zig-zag seam if an orderly and still sufficiently firm concatenation of needle-and bobbin threads is to be achieved by tying the stitch.
When changing from sewing a zig-zag seam to sewing a straight seam and vice versa, a readjustment of the tension of needle and bobbin thread cannot be avoided. Readjustment of the tension is mostly not possible the first time, but only after a few tension changes and subsequent sewing tests. This means that considerable time is lost.
In the production of festoon and fancy seams, it is known to use a twin needle sewing machine (German Pat. No. 285,182), which is equipped with a thread puller by which the thread of one needle is pulled out and offered to the other needle for penetration in order to avoid bending stresses of the needle. The control of the thread puller requires a relatively complicated fixer gear which is installed in the machine. The machine becomes thus a special machine for the production of two parallel seams where the thread of one needle is merely looped with that of the other needle in the manner of a festoon. As a single purpose machine, it is unsuitable for use in private households.

Method and device for forming an overcast seam with a zig-zag sewing machine


In a method for protected execution of a cryptographic calculation in which a key with at least two key parameters is drawn on, an integrity check of the key is performed, in order to prevent a cryptographic attack in which conclusions are drawn as to at least one second key parameter by corrupting at least one first key parameter. A further method serves to determine a key for a cryptographic calculation with at least two key parameters provided for use in the first-mentioned method. A computer program product and a portable data carrier have corresponding features. The methods enable particularly good protection of cryptographic calculations against attacks.

1. Field of the Invention
The invention relates in general to the technical domain of cryptography and more especially to a procedure for improved protection of a cryptographic calculation against attacks. The invention is provided in particular for use in portable data carriers, which can be configured as smart cards in different forms of construction or as chip modules, for example.
2. Description of the Related Art
The RSA method, described, e.g. in U.S. Pat. No. 4,405,829, is well known for the exchange of encrypted and/or signed data. According to the RSA method, a public key is used for encryption or signature verification and a secret private key for decryption or signature generation. Security of the RSA method is based on the fact that currently no efficient way of determining the prime factors p and q of a large number n with n=p·q is known. Whereas the so-called modulus n is published as part of the public key, the values p and q must be kept secret.
The calculation processes required for executing the RSA method are relatively complicated. For instance, the data to be processed have to be exponentiated with parameters of the private key during decryption or signature generation, for example. In particular for portable data carriers with their limited computing power, an implementation of the RSA method for decryption or signature generation is therefore frequently employed which uses the CRT (Chinese remainder theorem) and therefore is also designated as RSA-CRT method. By using the RSA-CRT method the required computing expenditure is reduced by approximately the factor 4.
The RSA-CRT method provides, instead of one complicated power calculation, to perform two far simpler exponentiations, the results of which are then combined into the decrypted data or the generated signature. Only the secret prime factor p enters into the first of these calculations and only the secret prime factor q into the second calculation.
Attack scenarios have been proposed, in which exactly one of the two named RSA-CRT calculation branches is interfered with, e.g. by deliberate action of heat or radiation or by electrical pulses. If this succeeds, a multiple of the prime factor p, q, whose calculation branch has not been interfered with can be derived from the result of the overall calculation. In other words, conclusions can be drawn as to the private key by means of the described attack. This has potentially catastrophic consequences, because not only the decryption or signature generation just performed, but all the cryptographic operations executed using the private key are compromised.
The attack just mentioned is known by the name "fault attack" or "Bellcore attack" and described, e.g., in column 4 of U.S. Pat. No. 5,991,415. Likewise in U.S. Pat. No. 5,991,415 a method is disclosed, in which an additional factor j enters into the calculation to protect against this attack which takes place during the cryptographic calculation. However, as will be shown below, there are further possibilities of attack, against which nothing can be done by the method known from U.S. Pat. No. 5,991,415.
Said possibility of attack is particularly critical if the cryptographic calculation is executed by a processor of a portable data carrier, for example a smart card or a chip module. A first reason for this is that portable data carriers of this kind are often used for security-critical applications, e.g. in connection with financial transactions, access control or the signature of legally binding documents. Secondly, portable data carriers are typically in the possession of the attacker while the cryptographic calculation is being executed, so this person has every opportunity to influence the calculation and to spy on the results of the calculation.


The present invention relates to the parallel calculation of convoluted data. In particular, the invention relates to Gaussian pyramid construction and parallel processing of image data, such as parallel calculation of repeatedly convoluted data for use in a SIFT algorithm. This is achieved by providing a method for obtaining a plurality of difference images from an original image defined by a plurality of pixels, said method comprising: Providing a plurality of blurring convolution functions, each of said blurring functions providing increasing degree of blurring of an original image upon convolution of said original image; establishing a plurality of difference convolution functions, Dif, by calculating the difference between two of said blurring convolution functions, each of said two blurring convolution functions providing different degrees of blurring of an original image upon convolution of said original image; and calculating a plurality of difference images from said original image, by convolving each of said difference convolution functions, Dif, with said original image to obtain difference images.

The conventional SIFT algorithm, inter alia disclosed in the U.S. Pat. No. 6,711,293 B1, discloses a method and apparatus for identifying scale invariant features in an image, and the use of these features for locating an object in an image.
The US patent application 2010/0169576 discloses a method for implementing a scale invariant feature transform algorithm, wherein a difference of Gaussian image may be obtained from convolving an input image with a difference of Gaussian filter. While the application purports that the processes may be conducted in parallel, the application is silent about actual parallel implementations.

Method and device for parallel processing of images


The invention provides a displacement sensor comprising a light-emitting element for projecting a detection light towards an object in a substantially perpendicular direction, a condensing element for condensing a reflected light from the object, and a position sensitive device with its light-receiving surface disposed in parallel with the axis of the detection light. A positioning apparatus employing the above displacement sensor is also disclosed.

There is known a displacement sensor utilizing a position sensitive device (hereinafter referred to briefly as PSD). Such a sensor is shown at 51 in FIG. 10 of the drawings accompanying this specification. This displacement sensor generally comprises a sensor head 52 housing a light-emitting element 53, which may be a light-emitting diode (LED) or a semiconductor laser, and a projection lens 54 on the light emission side and a condenser 55 and a PSD 56 on the light reception side. The operating principle of this sensor is that a detection light beam 58 from said light-emitting element 53 is obliquely incident on the object 57 and the light 59 reflected therefrom is condensed by said condenser 55 and received by the PSD 56. It is so arranged that the axis of the detection light beam 58 is at right angles (.theta.=90.degree.) with the light axis of the condenser 55. Since, in this sensor 51, the amount of displacement of the object 57 is proportional to the amount of shift in the point of incidence on the light-receiving surface of the PSD 56, the signal output of the PSD is linearly dependent on the amount of displacement of the object 57.
In this sensor 51, however, since both the light-emitting element 53 and the PSD 56 are obliquely disposed with respect to the surface of the object 57, the distance s between the light-emitting element 53 and the PSD 56 is greater than the detection distance L so that the bulk of the sensor head 52 is increased of necessity.
Illustrated in FIG. 11 is another known displacement sensor 61, wherein a light-emitting element 64 and a projecting lens 65 are disposed so as to project a detection light 63 perpendicularly towards the object 62 and, with the light-receiving surface of a PSD 66 being disposed perpendicularly with respect to the axis of a detection light beam 63, a condenser 69 for focusing a reflected light 68 on said PSD 66 is disposed in parallel with the axis of the detection light beam 63.
In this displacement sensor 61, the axis of the detection light beam 63 is at right angles with the light-receiving surface 67 of the PSD 66, the amount of shift in the point of light incidence on the light-receiving surface 67 of PSD 66 is not proportional to the amount of displacement of the object 62 so that the signal output of the PSD is not linearly dependent on the amount of displacement of the object 62, thus requiring a correcting circuit. Moreover, the focal plane, indicated at 70, which is formed by the reflected rays 68 on focusing by the condenser 69, does not coincide with the light-receiving surface 67 of PSD 66 as seen in FIG. 11, so that the reflected light 68 from the surface of said object 62 cannot always be focused on the light-receiving surface 67 of PSD 66.
FIG. 12 is a schematic view showing still another known displacement sensor 71. In this displacement sensor 71, a light-emitting element 74 and a projecting lens 75 are disposed so as to project a detection light beam 73 in a perpendicular direction with respect to the surface of an object 72 and, with the light-receiving surface of a PSD 76 being disposed perpendicularly with respect to the axis of a detection light beam 73, a condenser 79 is disposed in an inclined position so that a reflected light 78 from the object 72 is invariably incident on the light-receiving surface 77 of a PSD 76. However, even in this displacement sensor 71, where the axis of the detection light 73 is perpendicular to the light-receiving surface 77 of PSD 76, no linearly displacement-dependent signal output can be obtained from the PSD 76 as shown in FIG. 12 because, assuming that the object 72 is displaced by a.sub.1 and a.sub.2, the amounts of shift of focus, b.sub.1 and b.sub.2, on the light-receiving surface 77 of PSD 76 are not proportional, viz. EQU b.sub.1 /a.sub.1 .noteq.b.sub.2 /a.sub.2.
The technological background of positioning devices is now described briefly. FIG. 13 shows a schema for positioning a magnetic head 82 with respect to a disk 81 in an optical/magnetic disk system. This is a positioning system known as the focus error system. Here, a laser light 83 from a write laser diode is condensed by optics 84 onto the disk 81 to detect the distance from the disk 81 from the amount of defocus of the laser light 83 and this detection signal is fed back to the magnetic head 82 to maintain the magnetic head 82 at a predetermined distance from the disk 81.
In such a focus error system, however, there are limits to the range of in-focus so that the disk and laser diode must be exactly positioned beforehand. For this reason, high assembling accuracy is required for the laser diode and other devices and the assembly of a magnetic disk involves a time-consuming operation.
The system for positioning a magnetic head as shown in FIG. 14 detects the absolute position of a magnetic head 82 with a displacement sensor 93, which comprises a light-emitting element 91 and a PSD 92 such as those as illustrated in FIG. 10, and calcualtes the distance d between the magnetic head 82 and the disk 81 to thereby indirectly detect the position of the magnetic head 82.
Since, in this system, the distance d between the magnetic head 82 and the disk 81 is determined indirectly by calculation, the system has the drawback of fairly large positioning error.
In the impact dot printer, the printing head must be positioned with respect to the printing paper. In the conventional practice, the printing head is once advanced into contact with the paper for positioning and, then, carried back away from the paper over a predetermined distance to set the head in a necessary position relative to the paper.
However, this system involves a large-stroke movement of advancing the printing head into contact with the paper and carrying it back and requires a device for sensing the timing of the printing head contacting the paper and a mechanism for idling the printing head so that it will cease to advance as soon as it contacts the paper. Therefore, the system architecture is inevitably complicated.