An airfoil includes pressure and suction side walls that extend in a chord-wise direction between leading and trailing edges. The pressure and suction side walls extend in a radial direction to provide an exterior airfoil surface. A main-body core cooling passage is arranged between the pressure and suction walls in a thickness direction and extends radially toward a platform. A airfoil skin cooling passage is arranged in one of the pressure and suction side walls to form a hot side wall and a cold side wall. The hot side wall defines a portion of the exterior airfoil surface and the cold side wall defines a portion of the core passage. The airfoil skin cooling passage extends to a platform skin cooling passage arranged in the platform. The platform skin cooling passage resupplied by a backside of the platform.

This disclosure relates to gas turbine engines and particularly to internally cooled turbine vanes.
A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustor section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
As is well known, the aircraft engine industry is experiencing a significant effort to improve the gas turbine engine's performance while simultaneously decreasing its weight. The ultimate goal has been to attain the optimum thrust-to-weight ratio. One of the primary areas of focus to achieve this goal is the "hot section" of the engine since it is well known that engine's thrust/weight ratio is significantly improved by increasing the temperature of the turbine gases. However, turbine gas temperature is limited by the metal temperature constraints of the engine's components. Significant effort has been made to achieve higher turbine operating temperatures by incorporating technological advances in the internal cooling of the turbine blades.
Various cooling passage configurations have been used to cool turbine vanes, but there may be some inadequacies in some applications. To this end, a double wall cooling configuration has been used to improve turbine vane cooling. In a double wall blade configuration, thin skin core cavity passages extend radially and are provided in a thickness direction between the core cooling passages and each of the pressure and suction side exterior airfoil surfaces. Double wall cooling has been used as a technology to improve the cooling effectiveness of a turbine blades, vanes, blade out air seals, combustor panels, or any other hot section component.
Turbine vanes need cooling on both the airfoil and the platforms. Conventional investment casting processes limit cooling designs to "pullable" cores, separating the airfoil and platform cooling circuits. Typical vane cooling design configurations will have cast cooling circuits on the airfoils and machined cooling holes on platforms. Given relatively flat combustor temperatures, significant flow is required to cool vane platforms and mateface gaps. Interstage gaps between the stationary and rotating turbine stages require a balance of sealing and purge flow to prevent hot gas from entraining into these areas and damaging the unprotected backsides of these components as well as non gaspath components with lower temperature capability. Introducing cooling air into the gaspath as a coolant imparts a cycle penalty reducing fuel efficiency of the engine, therefore making it desirable to utilize as little cooling air a possible to protect turbine components.

Double wall turbine gas turbine engine vane platform cooling configuration with baffle impingement


A method of performing 4-dimensional virtual endoscopy includes acquiring a sequence of cardiac images of a patient's heart from an imaging device; acquiring an electrocardiographic signal exhibiting cardiac cycles of the heart; and utilizing the electrocardiographic signal to gate the images for deriving respective 3-dimensional views in succession at corresponding cardiac cycles, from respective cardiac images at a selected phase point common to each of the corresponding cardiac cycles.

Virtual endoscopy allows visualization of a scene setup from pre-acquired data. Images are created with a virtual camera interactively manipulated by a user. Imaging techniques currently in use and how the acquired data is visualized are first briefly reviewed below.
At the present time, computed tomography (CT) and magnetic resonance (MR) imaging are the two popular imaging techniques used to capture images of a patient's anatomy, in accordance with known techniques. With CT, different X-ray images taken from a rotational scanner are used to reconstruct a 3D volume. Images of various portions and parts of the internal anatomy will generally appear in an image with different intensities. With MR resonance, relaxation times from excited hydrogen molecules are measured. Using the right parameters, it is possible to image different tissues. Both techniques provide serviceable resolution. In another promising 3D imaging technique, ultrasound is used to create images by localizing sound echoes from an ultrasound emitter. Recent hardware apparatus allows 3D acquisition of data.
It is also possible to interpolate 3D volumes with the composition of 2D ultrasound frames. Acquired data can be visualized in a volume renderer, in a virtual endoscopy, or as single slices. It can be any arbitrary slice, called multi-planar reconstruction (MPR). By manipulating these slices, it is possible to get a 3D sense of the volume. In a volume renderer, the data is directly displayed in 3D. It is possible to rotate around the volume, and to zoom or pan the volume. By rendering certain intensities of the data, different tissues can be revealed. As an additional help to seeing inside, the volume can be cut or intercepted by an arbitrary plane.
In a virtual endoscopy, a virtual camera is located inside the volume. The camera can be moved or rotated and it is possible to change the camera parameters such as its field of view. To define what constitutes a cavity in the volume, an iso-surface value is chosen. Intensities below this value will be considered a cavity, and intensities above it will be rendered as opaque. In the endoscopic view, the boundary seen will therefore be dependent on the iso-surface value.
To render a virtual endoscopic view, two methods can be used: ray casting and iso-surface visualization. The first method casts rays from the virtual camera and detects when the rays hit the volume. At the boundary, the surface normal is used to compute the correct lighting of the current pixel. Each ray will generate a pixel on the screen. The second method extracts an iso-surface from the volume, for instance. with the marching cube algorithm. The resulting mesh is placed in a 3D world and the virtual camera can navigate the mesh. This can be efficiently done with OpenGL, or any other suitable graphic language. Background information can be found in the literature: see, for example, the literature cited below.
The current state of the art visualization remains mostly static. For an extensive review of current endoscopic methods see, for example, Anna Vilanova i Bartroli, "Visualization Techniques for Virtual Endoscopy", PhD thesis, Technische Universitat Wien, September 2001.
A 4D volume renderer and dynamic MPR are currently available: see, for example, Kostas Anagnostou, Tim J. Atherton, Andrew E. Waterfall, "4D volume Rendering With The Shear Warp Factorisation", Proceedings of the 2000 IEEE Symposium on Volume Visualization. pp. 129-137, 2000; however, this material does not show a 4D virtual endoscopy system.
Textbooks useful in providing background material helpful to gaining a better understanding of the present invention include, for example, VIRTUAL ENDOSCOPY and RELATED 3D TECHNIQUES by P. Rogalla et al., Springer, Berlin & New York, 2002, FUNDAMENTALS OF IMAGE PROCESSING by Arthur R. Weeks, SPIE Optical Engineering Press & IEEE Press; 1996; IMAGE PROCESSING, ANALYSIS, AND MACHINE VISION, Second Edition, by Milan Sonka et al., PWS Publishing; 1999; and DIGITAL IMAGE PROCESSING, Second Edition, by Rafael C. Gonzalez et al., Prentice Hall; 2002.

Method and apparatus for interactive 4-dimensional (4D) virtual endoscopy


In a brake control method of a power wheelchair, the power wheelchair includes an electronic gradienter, a brake sensor, a brake apparatus, and a brake controller. The electronic gradienter detects stability data of the power wheelchair to obtain a gradient angle and a gradient direction of the power wheelchair. When the gradient angle does not exceed a safety angle range, the brake controller controls the brake apparatus to brake the power wheelchair, and the brake sensor detects braking data of the power wheelchair. The method calculates a braking strength value for braking each wheel of the power wheelchair according to the gradient angle and the gradient direction of the power wheelchair when the brake operation on the power wheelchair is improper. The brake controller adjusts the brake apparatus to brake the power wheelchair according to the braking strength value of each of the wheels.

1. Technical Field
Embodiments of the present disclosure relate to wheelchair control systems and methods, and particularly to a power wheelchair having a brake control system and a brake control method of the power wheelchair.
2. Description of Related Art
Attendant operated patient transport vehicles may be characterized as either a manual wheelchair type or a power wheelchair type with a joystick attendant control. Each of these transport vehicles has certain advantages and disadvantages. The manual brakes of a conventional manual wheelchair are located on the front of the manual wheelchair and designed as parking brakes. Frequently, the user fails to engage the parking brakes of a power wheelchair when the occupant is getting on or off of the power wheelchair and this may lead to further injuries. Furthermore, since the parking brakes are located on the front of the power wheelchair, the user cannot engage the parking brakes while the power wheelchair is in motion such as descending a ramp.
Therefore, there is a need to provide an improve power wheelchair having a brake control system and a brake control method of the power wheelchair, to address the foregoing mentioned problems.

Power wheelchair and brake control method of the power wheelchair

Zhongshan Innocloud Intellectual Property Services Co., Ltd.


The present invention provides an interactive device which allows quick utterance recognition results and sequential output thereof and which diminishes a recognition rate decrease even if user's utterance is divided by a short interval into frames for quick decision. The interactive device: sets a recognition section for voice recognition; performs voice recognition for the recognition section; when the voice recognition includes a key phrase, determines response actions corresponding thereto; and executes the response actions. The interactive device repeatedly updates the set recognition terminal point to a frame which is the predetermined time length ahead of the set recognition terminal point to set a plurality of recognition sections. The interactive device performs voice recognition for each recognition section.

1. Field of the Invention
The present invention relates to an interactive device that performs a response action corresponding to the contents of utterance by a user.
2. Description of the Invention
Interactive devices are utilized in communication robots and the like capable of communicating with users and are required to recognize user's input voice that is continuous without clear breaks between sentences. Accordingly, the interactive devices employ a continuous voice recognition system using statistical voice recognition processes. One-path search and multi-path search are known as search algorithms in such statistical voice recognition processes.
The one-path search is a method to search word candidates only once in the input voice as shown in FIG. 16A. Since the one-path search performs a continuous search throughout duration of utterance by the user from the starting end to the terminal end, the one-path search has an advantage of a relatively high recognition accuracy. The one-path search, however, has a difficulty using complicated models (acoustic models and language models) which requires processing of an increasing amount of data as the vocabulary becomes large.
For this reason, the multi-path search has been well used that performs a plurality of searches on the contents of the user's utterance, as shown in FIG. 16B. In the multi-path search, as shown in FIG. 16B, first, a first-path search is performed in a direction from the starting end to the terminal end of the utterance duration using simple (coarse) models, and then, a second-path search is performed in a direction from the terminal end to the starting end of the utterance duration using complicated (sophisticated) models. The multi-path search is advantageous in that it is easy to implement a multi-path search software into the device because the volume of the entire computing data is reduced due to the switch from a simple model in the first-path search to a sophisticated model in the second path search.
On the other hand, the multi-path search shown in FIG. 16B has a problem that a voice recognition result is unable to be output until the second-path search is completed up to the terminal end of the utterance duration. That is, in the multi-path search as shown in FIG. 16B, which does not allow a timely sequential output of recognition results halfway through the utterance duration, a key phrase to determine a response action is unavailable until a recognition result is output at the terminal end of the utterance duration even if the key phrase has already appeared halfway through the utterance duration. This is the reason that there is a need to make quick decision of voice recognition results halfway through the utterance duration according to certain criteria so that the voice recognition results can be output sequentially while the voice is being input by the user.
To solve this problem, there have been proposed continuous recognition techniques of dividing an utterance duration into sections of a predetermined length, allowing quick decision of recognition results with respect to these sections and sequentially outputting the thus obtained recognition results, as shown in FIG. 16C (For example, Japanese Unexamined Patent Publication No. 6-259090 (See FIG. 1) (hereinafter referred to as Patent Document 1); O. Segawa, K. Takeda and F. Itakura: Continuous Utterance Recognition without End-point Detection, Voice Language Information Processing, 34-18, pp. 101-106, December 2000 (hereinafter referred to as Nonpatent Document 1); T. Imai, H. Tanaka, A. Ando and H. Isono: Progressive Early Decision of Utterance Recognition Results by Comparing Most Likely Word Sequences, The Journal of the Institute of Electronics, Information and Communication Engineers (J. IEICE), D-II, Vol. J84-D-II, No. 9, pp. 1942-1949, September 2001) (hereinafter referred to as Nonpatent Document 2). Such continuous recognition techniques are utilized mainly in automation of, for example, phonetic transcription of utterances and preparation of subtitles using a voice recognition system.
Patent Document 1 proposes a voice interactive system that recognizes input voice in an utterance duration, extracts a sequence of semantic expressions from the input voice, divides the sequence of semantic expressions into units of meaning and performs processing of each unit of meaning. Nonpatent Document 1 proposes a technique of setting a frame interval, for which quick decision is made, to 1.5-3 seconds and searching, in a first-path search, a last word in and around each frame interval to thereby prevent a decrease in a recognition rate resulting from a short utterance duration. Nonpatent Document 2 proposes a continuous voice recognition technique of searching a last word that enables quick decision by comparing most likely word sequences for every interval of 300 msec in a one-path search, thereby reducing an average delay time in word decision to 512 msec.
However, the techniques of Patent Document 1 and Nonpatent Documents 1 and 2, which use a result of the first-path search (hereinafter referred to as the first path where appropriate) for specifying intervals at which user's utterance is divided into frames for quick decision, have a problem that a word division error, if any, in a search result of the first path affects a search result in the second path search (hereinafter referred to as the second path where appropriate), resulting in a decreased recognition rate.
Further, continuous recognition through voice interaction requires faster responses than that for phonetic transcription of utterances and preparation of subtitles, and thus requires quick decision to be made at shorter intervals. In the techniques of Patent Document 1 and Nonpatent Documents 1 and 2, if the response speed is increased by shortening each of the intervals by which user's utterance is divided into frames for quick decision, the length of each of voice recognition sections is reduced, making it difficult to search for word boundaries and thereby decreasing the recognition rate.
The present invention has been made in view of the above problems, and it is an object of the present invention to provide an interactive device which allows quick decision of utterance recognition results and sequential output of the utterance recognition results and which diminishes a decrease in the recognition rate even if user's utterance is divided by a short interval into frames for quick decision.
In order to solve the above problems, the present invention provides an interactive device that recognizes input voice of a user and thereby contents of utterance of the user and performs a predetermined response action corresponding to the recognized contents, the interactive device comprising:
a recognition section setting means that sets a recognition starting point to an utterance starting end frame serving as a starting end of the user's utterance in the input voice and sets a recognition terminal point to a frame which is a predetermined length of time ahead of the recognition starting point to thereby set a recognition section throughout which voice recognition is performed,
a voice recognition means that performs voice recognition for the recognition section,
a response action determining means that, if a recognition result by the voice recognition means includes a key phrase, determines a response action associated with the key phrase, and
a response action executing means that executes the response action determined by the response action determining means,
the recognition section setting means repeatedly updating the frame set as the recognition terminal point to a frame which is the predetermined length of time ahead of the recognition terminal point, to thereby set a plurality of recognition sections having different recognition terminal points, and
the voice recognition means performing voice recognition on each of the plurality of recognition sections having different recognition terminal points.
In the interactive device as described above, the recognition section setting means divides the user's utterance duration at the recognition terminal points into predetermined lengths of time to set a plurality of recognition sections having different lengths. The voice recognition means performs voice recognition with respect to each of the recognition sections. This allows quick decision of a voice recognition result at every recognition terminal point. That is, a recognition result (a partial recognition result) can be output for each of the plurality of recognition sections.
Preferably, the interactive device according to the present invention has a construction that the recognition section setting means comprises:
a recognition starting point setting unit that detects the utterance starting end frame and sets the recognition starting point at the detected utterance starting end frame,
a recognition terminal point setting unit that sets the recognition terminal point at a frame which is the predetermined length of time ahead of the recognition starting point set by the recognition starting point setting unit; and
a recognition terminal point updating unit that updates repeatedly the recognition terminal point set by the recognition terminal point setting unit to a frame which is the predetermined length of time ahead of the recognition terminal point,
the recognition terminal point updating unit detects an utterance terminal end frame serving as a terminal end of the user's utterance in the input voice and updates the recognition terminal point to the detected utterance terminal end frame, said recognition terminal point being either one of the recognition terminal point set by the recognition terminal point setting unit and the recognition terminal point updated by the recognition terminal point updating unit,
the voice recognition means comprises:
a first-path searching unit that searches word candidates in the user's utterance in a direction from the utterance starting end frame to the utterance terminal end frame, and
a second-path search unit that searches the word candidates in each of the plurality of recognition sections having different recognition terminal points in a direction from the recognition terminal point to the recognition starting point according to a search result produced by the first-path searching unit, and
the response action determining means determines, when a search result produced by the second-path search unit includes the key phase, the response action corresponding to the key phrase.
In the interactive device as described above, the recognition terminal point updating unit updates repeatedly a recognition terminal point to a frame which is a predetermined length of time ahead of the recognition terminal point to thereby set a plurality of recognition sections of different lengths. The first-path searching unit performs a search throughout user's entire utterance duration, and the second-path searching unit performs a search with respect of each of the plurality of recognition sections, achieving voice recognition improved both in speed and accuracy.
Further, preferably, the interactive device according to the present invention has a construction that the recognition section setting means comprises a recognition starting point updating unit that, when the search result by the second-path search unit includes a break in the user's utterance, updates the recognition starting point set by the recognition starting point setting unit to a frame located at a top of the break in the user's utterance, and
the second-path search unit searches the word candidates with respect to each of the plurality of recognition sections having different recognition starting points and different recognition terminal points.
In the interactive device as described above, if a break in the user's utterance duration such as a short pause, a filler or the like is detected by the second-path searching unit, the recognition starting point updating unit updates the recognition starting point to a frame located at the top of the break in the utterance duration. Thus, in the interactive device, even if the recognition terminal point updating unit updates the recognition terminal point repeatedly to prolong the recognition section stepwise, the recognition starting point updating unit is able to prevent the recognition section from becoming too long. Consequently, the interactive device is advantageous in that it is able to prevent an excessive prolongation of each recognition section to be reversely searched by the second-path search, which results in a reduction of a time taken by the second-path search in a proper response speed.
Still further, preferably, the interactive device according to the present invention has a construction that the key phrase included in the search result by the second-path search unit is made up of a plurality of words.
In the interactive device as described above, the response action determining means determines a response action according to whether or not a search result by the second-path searching unit includes a key phrase made up of a plurality of words. Thus, the interactive device, when continuous voice recognition is performed with respect to each of short lengths of time (for example, 200 msec) obtained by dividing the user's utterance duration, can determine a response action more accurately and more precisely because determination of a response action is not based on a single word candidate so that an error word-candidate in the search results of the second-path searching unit does not affect the determination of the response action.
Yet further, preferably, the interactive device according to the present invention has a construction that the second-path searching unit calculates a word reliability factor indicative of a degree of plausibility of the searched word candidate, and
the response action determining means determines, when the search result by the second-path searching unit includes the predetermined key phrase and when the word candidates corresponding to the key phrase have word reliability factors each above a predetermined value, the response action corresponding to the key phrase.
In the interactive device as described above, the response action determining means determines a response action only when a search result by the second-path searching unit includes a key phrase and word candidates corresponding to the key phrase have word reliability factors above a predetermined threshold value. Thus, the interactive device determines a response action more accurately and more precisely than conventionally.
Yet further, preferably, the interactive device according to the present invention has a construction that it further comprises:
a response action storing means that stores, in relation with each other, the key phrase, the response action corresponding to the key phrase, and a response action category serving as a category of the response action, and
a response action history storing means that stores a history of response actions already determined by the response action determining means,
wherein, when the search result by the second-path search unit includes the key phase, the response action determining means judges, by referring to the response action storing means and the response action history storing means, whether or not a response action category of a response action determined currently by the response action determining means and a response action category of a response action determined previously by the response action determining means are the same, and determines, when the both categories are the same, the response action corresponding to the key phrase.
In the interactive device configured as described above, the response action determining means determines a response action only when the response action and currently determined response action belong to the same category as that of the previously determined response action. Consequently, the interactive device is able to prevent determination of a response, which is based on a wrong search result produced by an error in a search by the second-path searching unit, and which is totally irrelevant to action according to an error a wrong search result by the second-path searching unit that is not related with the previously determined response action.
Yet further, preferably, the interactive device according to the present invention has a construction that, when a response action determined according to a last search result by the second-path search unit and a response action determined according to a previous search result by the second-path search unit are different, the response action executing means executes the response action determined according to the last search result.
In the interactive device configured as described above, the response action executing means executes the response action according to the final second-path search result by the second-path searching unit. Thus, the interactive device is able to prevent a wrong response action from being executed even if the response action according to the second-path search result by the second-path searching unit is produced by an error.
Yet further, preferably, the interactive device according to the present invention has a construction that, when a last search is performed by the second-path search unit after the start of an execution of a response action determined by the response action determining means and when a result of the last search and a result of a previous search corresponding to the response action currently being executed are different, the response action executing means cancels the response action currently being executed and executes a predetermined response action for correcting the response action currently being executed and then executes a response action determined by the response action determining means according to the last search result by the second-path search unit.
In the interactive device configured as described above, when the second-path searching unit produces an error second-path search result halfway through the user's utterance duration and a response action is already determined and executed according to the error second-path search result, the error second-path search result is able to be corrected and the final second-path search result at the terminal end of utterance duration by the second-path searching unit can be adopted to exert a response action.
According to the interactive device of the present invention, by dividing the user's utterance duration by a predetermined length of time into a plurality of recognition sections, performing continuous voice recognition with respect to each of the plurality of recognition sections, a proper response speed required for continuous recognition of the plurality of recognition sections is ensured while preventing an excessive prolongation of each recognition section and thus preventing a reduction in the recognition rate thereof.

Interactive device that recognizes input voice of a user and contents of an utterance of the user, and performs a response corresponding to the recognized contents


A gaseous carburetor or fuel control system includes a fuel metering assembly, a venturi mixer assembly, a throttle assembly, and an electronic control unit. The control unit controls the fuel metering assembly in a closed loop manner based on detected gas and air pressure to an air/fuel mixing venturi. An electronic governor which controls the throttle valve may also be controlled by the same control unit which controls the fuel metering assembly, using a separate control loop.

1. Field of the Invention
This invention relates generally to devices and systems for mixing natural gas or any gaseous fuel with air in the correct proportions for combustion in a gas engine, and is particularly concerned with a fuel control system and method for controlling a natural gas engine for the purpose of reducing exhaust emissions and improving engine performance.
2. Related Art
The main concern that engineers had when designing the older engines and their fuel systems was engine performance and durability without any regard for exhaust emissions. Over the years numerous systems for controlling emissions have evolved utilizing a catalytic converter, an exhaust gas sensor, and a fuel modulating system to control the mixture for reduced emissions.
Some of the prior art devices that have been used rely on various types of supplemental fuel metering, biasing on pneumatic pressure regulator, or limited throttling of the main fuel supply. They have required substantial amounts of external support equipment and electrical interconnections. They have suffered from slow response and generally have not been particularly easy, convenient or economical to install, operate or use. Few have had any significant degree of self-containment or full fuel authority.

Fuel control system and method for gas engines


The present invention provides an apparatus and method for inspecting a circuit board at a high speed. A PDP driver module 100 as an object to be inspected has an onboard PDP driving LSI 110. A plurality of circuit wirings 111 are connected to terminals of the LSI. An inspection apparatus 1 generates an LSI drive signal and sends it to input terminals 113 of the LSI 110. A sensor 2 is positioned opposedly to the circuit wirings 111 in a non-contact manner. The sensor 2 detects voltage values in circuit wirings 111 caused by driving the LSI 110, and the detected signals are analyzed by the inspection apparatus 1.

In manufacturing processes of a circuit board, after forming circuit wirings on a board, it is required to inspect the presence of a disconnection or open circuit in the circuit wirings.
Heretofore, an open circuit state in circuit wirings on a circuit board has been determined by bringing a pair of pins into contact with two different portions of each circuit wiring and then checking conduction between the positions.
However, in an area of the circuit board, such as the vicinity of an integrated circuit, where the circuit wirings are formed in close proximity to each other, it is difficult to assure a sufficient interval between the pins. On the other hand, a non-contact type inspection method (Japanese Patent Laid-Open Publication No. 09-264919) has been proposed. However, since this inspection method has still been required to bring one pin into contact with each input section of the circuit wirings, it has been suffered from complicated and time-consuming positioning operations when circuit wirings such as those around an integrated circuit are in close proximity to each other and each of the circuit wirings has a short length.
In view of the problems in the above conventional methods, it is therefore an object of the present invention to provide an apparatus and a method capable of inspecting a circuit board at a high speed.

This patent is subject to a terminal disclaimer.

Inspecting apparatus and inspecting method for circuit board


This inverter system is directed to an inverter system in which a plurality of inverters adapted for generating output voltages corresponding to a voltage reference and a frequency reference respectively given through voltage controllers and frequency controllers are operated in parallel. In this inverter system, a difference between an output current of a corresponding inverter and output currents of other inverters is detected. By implementing the d-q axis orthogonal coordinate transform processing to that current difference, a first correction signal relating to the frequency of an output voltage of that inverter and a second correction signal relating to the amplitude of the output voltage thereof are provided.

1. Field of the Invention
This invention relates to an inverter system comprised of a plurality of inverters operated in parallel, and more particularly to an inverter system capable of keeping balance of sharing of load between respective inverters even in the case where a load undergoes a sudden change.
2. Prior Art
In the case where a required capacity cannot be ensured by a single inverter, or in the case where the reliability is required to be improved as a power supply system using inverter, there are many instances where a plurality of inverters may be operated in parallel. In this case, in order to allow an inverter system to have a capacity corresponding to the number of inverters operated in parallel, it is required to cause respective inverters to equally share the load.
Referring to FIG. 1, there is shown an example of the configuration of a conventional control system constituted with a view to keeping balance of sharing of load between inverters (see Japanese Patent Publication (JP-B}No. 46955/1983). This control system is directed to a control system adapted for operating in parallel two inverters 3a and 3b. The first inverter 3a is included in a first inverter unit 1a, and the second inverter 3b is included in a second inverter unit 1b. Each of these inverter units 1a and 1b converts a d.c. power delivered from a d.c. power supply 2 to an a.c. power to deliver it to a load 20. It is to be noted that, in this specification, suffix a is attached to reference numerals indicating components belonging to the first inverter unit 1a and suffix b is attached to reference numerals indicating components belonging to the second inverter unit 1b, thus to discriminate between respective components of the both inverter units. The d.c. power supply 2 may be comprised of an a.c. power supply and a rectifier, or may be comprised of a battery. Furthermore, such d.c. power supply 2 may employ the above-mentioned both power supply systems suitably in combination. In addition, d.c. power supplies may be separately on the inverters 1a and 1b sides, respectively. To the output terminals of the inverters 3a and 3b, a.c. filters 4a and 4b for improvement of waveform are connected, respectively. There are many instances where a.c. filters of this kind are comprised of a reactor and a capacitor. However, in the case where transformers are respectively connected between the inverter 3a and the load 12, and between the inverter 3b and the load 12, impedance of each transformer itself may be substituted for discrete reactor.
Output currents Ia and Ib of the inverters 3a and 3b are detected by current detectors 11a and 11b on the output side of the a.c. filters 4a and 4b, respectively. In the first inverter unit 1a, a current difference .DELTA.Ia =Ia-Ib is provided by a subtracter 12a. Similarly, in the second inverter unit lb, a current difference .DELTA.Ib =Ib-Ia is provided by a subtracter 12b. A common output voltage V of the both inverter units 1a and 1b is detected by voltage detectors 13a and 13b. On the basis of the voltage V and the current differences .DELTA.Ia and .DELTA.Ib detected in this way, an effective power detector 9a calculates an effective power difference .DELTA.Pa=V.multidot..DELTA.Ia.multidot.cos.theta., and an effective power detector 9b calculates an effective power difference .DELTA.Pb=V.multidot..DELTA.Ib.multidot.cos.theta.. Furthermore, on the basis of the same detected values as above, a reactive power detector 10a calculates a reactive power difference .DELTA.Qa=V.multidot..DELTA.Ia.multidot.sin.theta., and a reactive power detector 10b calculates a reactive power difference .DELTA.Qb=V.multidot..DELTA.Ib.multidot.sin.theta.. It is to be noted that .theta. is assumed to be a phase difference between a detected voltage and a detected current. The output of a synchronous control circuit comprised of a frequency reference oscillator (OSC) 7a and a synchronous controller (PLL) 8a is controlled on the basis of the effective power difference .DELTA.Pa. Similarly, the output of a synchronous control circuit comprised of a frequency reference oscillator (OSC) 7b and a synchronous controller (PLL) 8b is controlled on the basis of the effective power difference .DELTA.Pb. Each of the power differences .DELTA.Pa, .DELTA.Pb, .DELTA.Qa and .DELTA.Qb corresponds to a voltage signal converted by multiplying a conversion coefficient, in the corresponding power detector. The frequency reference oscillators 7a and 7b deliver a frequency reference for to the synchronous controllers 8a and 8b. The synchronous controllers 8a and 8b generate frequency control signals for gate signal generators (PWM) 5a and 5b adapted for generating firing control pulses for PWM (Pulse Width Modulation) control, respectively. Furthermore, voltage controllers (VC) 6a and 6b basically serve to allow a voltage V detected by the voltage detectors 13a and 13b to be in correspondence with a voltage reference Vr. In this example, the voltage controllers 6a and 6b correct amplitudes of output voltages of the respective inverter units on the basis of reactive power differences .DELTA.Qa and .DELTA.Qb so that output currents Ia and Ib of the both inverters 3a and 3b are balanced to output control signals for voltage amplitudes to the gate signal generators 5a and 5b, respectively. On the basis of the control signals delivered from the synchronous controllers 8a and 8b and the voltage controllers 6a and 6b, the gate signal generators 5a and 5b control output voltages of the respective inverters 3a and 3b.
In the inverter system of FIG. 1, control is carried out such that respective inverter units 1a and 1b equally share a power, i.e., a current to the load 20 on the basis of effective power difference .DELTA.Pa and .DELTA.Pb and reactive power differences .DELTA.Qa and .DELTA.Qb. Each of the effective power detectors 9a and 9b adapted for detecting effective power differences .DELTA.Pa and .DELTA.Pb and the reactive power detectors 10a and 10b adapted for detecting reactive power differences .DELTA.Qa and .DELTA.Qb detects an average value of a power in place of an instantaneous value of a power. Namely, this control system is directed to a system adapted for controlling, on the basis of the above detection, an average value of a power instead of an instantaneous value of a power. For this reason, this control system not only requires a time for calculating an average value, but also includes a filter serving as a delay element in the power detection system. Accordingly, with this control system, delay in detection would be increased. For this reason, for example, in such cases where the load 20 suddenly changes, there was the possibility that there may transiently take place an unbalance in the load sharing of the respective inverter units la and lb, particularly in an extreme case, an inverter unit which has shared a more current may be brought into an overload state, leading to stop of operation.

Current sharing control in a parallel inverter system


The invention relates to a method of operating a three phase primary winding structure of a system for inductive power transfer, wherein the primary winding structure includes a first phase line, a second phase line and a third phase line, wherein in a standard operational mode a first phase input voltage, a second phase input voltage and a third phase input voltage are controlled such that a predetermined phase shift between all three phase input voltages is provided, wherein in a modified operational mode the first phase input voltage, the second phase input voltage and the third phase input voltage are controlled such that the set of phase shift values includes at most two non-zero values and all non-zero phase shift values are equal. Furthermore, the invention relates to a primary unit of a system for inductive power transfer.

Field of the Invention
The invention relates to a method of operating a three phase primary winding structure of a system for inductive power transfer and a primary unit of said system for inductive power transfer.
Description of Related Art
Vehicles, in particular electric vehicles and/or a track-bound vehicle and/or a road automobile, can be operated by electric energy which is transferred by means of an inductive power transfer.
The inductive power transfer is usually performed using a primary unit which generates an alternating electromagnetic field and a secondary unit which comprises a receiving device for receiving said electromagnetic field.
The primary unit and the secondary unit can e.g. each comprise a set of three-phase windings. A set of windings of the primary unit can be installed on the ground (primary winding structure) and can be fed by a wayside power converter (WPC). A set of windings of the secondary unit (secondary winding structure) is installed on the vehicle. For example, the secondary winding structure can be attached underneath the vehicle, in the case of trams under some of its wagons.
Furthermore, such a vehicle can comprise a rectifier adapted to convert an alternating current (AC) to a direct current (DC). The DC can be used to charge a traction battery or to operate an electric machine. A rectifier converts the AC provided by the receiving device into the DC.
The first and the secondary side, in particular the primary and the secondary winding structure, can be part of a high frequency transformer to transfer electric energy to the vehicle. This transfer can be done in a static state (when there is no movement of the vehicle) and in a dynamic state (when the vehicle moves).
To provide an efficient inductive power transfer, it is desirable to have a tuned inductive power transfer system. This means that a resonant frequency of primary and secondary winding structures which depends on the capacitive and inductive elements of these winding structures matches a predetermined operating frequency. In a tuned system, the maximal power transfer efficiency can be reached.
The aforementioned resonant frequency depends on the mutual coupling between the primary and secondary winding structure. As the mutual coupling depends on an alignment of the primary winding structure relative to the secondary winding structure, the alignment will have an impact on the power transfer efficiency. In particular in the case of a misalignment, the power transfer efficiency decreases.
Moreover, if power needs to be transferred to an automobile inductively, it is desirable to have small dimensions of a primary unit. In this case, however, even small misalignments will result in a significant decrease of the power transfer efficiency.

Method of operating a three phase primary winding structure and a primary unit


A method and system are provided for maintaining profiles of information channels available on the Web, wherein the information channels are accessed via pull-only protocols. The method includes monitoring one or more channels by a channel pull action at a monitoring rate, wherein the monitoring rate is determined for the one or more channels based on the number of update events in a previous time period. The method may optimally include filtering the update events in the time period by a novelty measure, wherein the filtering disregards events that do not include significant novel information. The monitoring rate is adapted based on reinforcement learning applying iterative learning rules over time.

Much of the content on the Web is available through syndication channels which need to be actively monitored to maintain an up-to-date profile of their published information over time. Such monitoring is essential for next generation of Web 2.0 applications that provide sophisticated search and discovery services over Web information channels. A channel's profile can change over time due to the dynamic nature of the channel. Therefore, maintaining a fresh channel profile is extremely difficult, especially under the constraint of a limited monitoring budget.
The number of diverse information channels available on the Web is rapidly increasing. It spans many different knowledge domains such as news, stock and market reports, auctions, and more recently channels containing data gathered from Blogs or Wikis. Recent advances in Web technology, such as the improved access capabilities to channels and the availability of new data delivery mechanisms for disseminating the channel content, have resulted in the emergence of more advanced client-side Web applications.
These applications require sophisticated manipulation of channels on the Web including the discovery, search, and recommendation of relevant channels. Such applications include various Web 2.0 mashups, and situational applications in general, which integrate data that is gathered from several different, possibly inter-related, channels. An imperative task for developers of such applications is to locate relevant channels that will maximize the benefit gained from their applications.
A crucial step toward the support of such advanced services over channels is the ability to capture the essence of each Web channel. This can be done using channel profiles. A channel profile is a compact representation of the channel content, which can be used to summarize and capture the main characteristics of the content published on this channel. Profiles can simplify the way relevant channels can be located and can be used to match application requirements against the available set of channels managed by the system.
Maintaining channel profiles is challenging due to several reasons. First, channel content is usually dynamic, as in the case of Web feeds where the content is continuously changing, sometimes at a daily or even hourly rate. Because the profiles of such channels may continually change over time, capturing the dynamic trends of the channel content is extremely difficult.
Second, the majority of channels on the Web are available nowadays for access via pull-only protocols, while most servers refrain from supporting push protocols due to scalability issues. Previous work on novelty detection in data streams, and data stream summarization, assume that the stream of updates to a channel is pushed into the system. By contrast, in a pull based scenario each channel is required to be actively monitored in order to maintain enough snapshots to construct a fresh and reliable profile of its content. The freshness of maintained profiles therefore directly depends on the rate at which channels are monitored. Moreover, different channels may have different rates at which novel content is being published on them; thus profiles of different channels may change at a different (possibly even non-regular) rate.
Third, in the pull-based scenario, channels may be volatile, meaning that novel content published over time has a limited lifespan during which it is available on the channel. Such data volatility is very common in Web feeds, where channels have a limited capacity for the number of feed entries that are maintained on the feed. Such limitation is further determined by the feed popularity and the feed provider update policy (e.g., an overwrite policy for which the provider maintains only the last newest entries of the feed). Therefore, monitoring the channel profiles in a pull setting is challenging, where it is hard to predict the moments when novel content, which may result in a significant profile change, is published on such volatile channels and is still available for access.
Finally, channel monitoring can be constrained, either due to limited system resources such as bandwidth, memory, or CPU (central processing unit), or due to monitoring restrictions set by the channel providers themselves (sometimes termed "politeness constraints") due to heavy workloads imposed by multiple client access. Therefore, the number of channels that can be monitored in parallel is further limited and requires efficient utilization of the allocated resources for the maintenance of fresh profiles.

Method and system for maintaining profiles of information channels

International Business Machines Corporation


A method for performing a broadcast for information sharing based on Wi-Fi is disclosed in the present document. The method includes: when a broadcast data request is detected, acquiring target information to be broadcasted in the broadcast data request; according to a preset configuration rule, configuring the target information to generate broadcast data; and broadcasting the broadcast data through the Wi-Fi for a receiving terminal to receive, parsing the broadcast data to obtain the target information, and displaying the target information. A device for performing a broadcast for information sharing based on Wi-Fi is also disclosed in the present document. With the present document, broadcasting and receiving of information can be achieved in a case of not establishing a connection between user terminals.

For the current Wi-Fi terminals, before performing data transmission and information sharing, a connection must be established between the terminals. With regard to a plurality of data transmissions with a very small amount of data, the overheads for establishing the connection between the terminals may exceed the data transmission itself, such as transmitting a phone number or transmitting an internet address and so on.
In addition, for sharing of certain public information, such as public transportation information of the bus station, railway timetable information of the railway station, weather information and location information and so on, it is more inclined to use a broadcast mechanism. The broadcast mechanism is a way that information can be released without establishing a connection between the terminals, which has features such as convenient maintenance, low costs and no excessive user interventions.

Method and device for conducting information sharing broadcast based on Wi-Fi


In a mobile phone, even when an audio-related function is running in background processing in parallel with a function running in the main processing (foreground processing) where operations by the main operating section have been assigned to the function running in the main processing, the control section operates the audio-related function based on a user operation detected by the touch screen, the imaging section, the sound collecting section, or the housing movement detecting section.

1. Field of the Invention
The present invention relates to a terminal device including a display section and an operating section, which is capable of running a plurality of functions including an audio-related function in parallel, and a control program thereof.
2. Description of the Related Art
In recent years, there has been growing improvement in the processing capacity of mobile phones, and parallel processing that, for example, allows a user to read received mail or access a website while listening to music is becoming possible. In such a case where a function for viewing received mail or a function for viewing a website on the Internet is running in main processing (foreground processing), and a music player function is running in the background processing, when an operation related to music such as song selection is performed, a procedure is required to be performed in which the music player function is temporarily switched to run in the main processing and then switched back to run in the background processing.
However, when a procedure such as described above is performed, the user is inconvenienced.
Therefore, conventionally, there has been disclosed a technology that enables a music player function running in background processing to be operated by providing a second operating section (refer to, for example, Japanese Patent Application Laid-Open (Kokai) Publication No. 2004-173137).
In the above-mentioned conventional technology, because a dedicated operating section is provided to enable the operation of a function related to music running in background processing, even when a music playback function and another function are performed in parallel, operations related to music can be performed without terminating a function other than the music playback function. However, on the other hand, providing a dedicated operating section causes new problems such as an increase in cost and a difficulty in miniaturization.

Terminal device configured to run a plurality of functions in parallel including an audio-related function, and control program thereof


A protective helmet assembly to be worn on the head of a person includes a rotective shell and a removable, adjustable suspension system mounted on the inner surface of the shell. The suspension system includes an impact liner mounted on the inner surface of the protective shell, a plurality of sizing pads removably mounted on the impact liner, and a plurality of spare sizing pads. The plurality of sizing pads and spare sizing pads are sized and shaped of varying thickness so as to enable the protective helmet assembly to accommodate a broad range of head sizes and shapes. The protective helmet assembly further includes a pair of earcups pivotally mounted on opposite sides of the shell. Each of the earcups are pivotally adjustable by a pair of ratchet buckles mounted on the protective shell, and a pair of retainer straps. Each retainer strap is attached to the outer surface of one of the earcups and to one of the ratchet buckles. When each retainer strap is tightened by stepwise adjusting the retainer strap through one of the ratchet buckles, the retainer strap pulls the earcup pivotally inward creating a tight pressure seal around the ear of the head of the person. The protective helmet assembly additionally includes a vertical strut mounted on both the front/left side and front/right side of the protective shell, each vertical strut including a hooked-shaped slot, and a facemask having a left end and a right end. The facemask includes a pair of pins, one mounted on the left end and one mounted on the right end, each pin being pivotally mountable in one of the hooked-shaped slots.

The present invention relates generally to protective helmets, and more specifically to a combat vehicle crewman (CVC) helmet assembly which provides ballistic, aural, head, and facial protection.
The provision of a helmet assembly which will comfortably fit combat crewman (CVC) while providing the requisite ballistic, aural, head, and facial protection as well as acoustic attenuation has presented a problem of long standing in the art. Such a helmet assembly should afford the wearer with a larger measure of ballistic protection, protection from injury resulting from contact with surfaces within the vehicle and it should limit the noise from within the vehicle which reaches the wearer's ear to a level which will not interfere with communication or damage hearing. All of the foregoing must be accomplished in headgear which is not unduly heavy, which may be adjusted to fit various size heads, which will not interfere with the required activities of the wearer and which may be worn with relative comfort for long periods of time. There has not previously been a helmet which would meet all these requirements.
In U.S. Pat. No. 4,023,209 to Frieder, Jr. et al, which issued May 17, 1977, there is disclosed a protective helmet assembly which includes a flexible inner helmet designed to fit relatively closely over a wearer's head and fitted with one or more impact-absorbing pads, and a hard rigid ballistic outer shell comprising a frontal portion releasably secured over the forehead area of the inner helmet and a rear portion releasably secured over the crown-to-nape area of the inner helmet, and in which assembly the inner helmet is provided with a pad of relatively flexible ballistic material in the forehead region thereof below the frontal portion of the outer shell.
It should be noted that the above-described protective helmet assembly has certain drawbacks. For instance, the aforementioned protective helmet assembly includes only a removable inner helmet; the inner helmet is not adjustable, thereby precluding such an assembly from accommodating a broad range of head sizes.
It is also very common in the prior art for protective helmet assemblies to use chinstraps to retain the earcups and provide earcup pressure to the head. Traditionally, the chinstrap is attached to the earcup to the wearer's head. Alternative methods for applying earcup pressure to the wearer's head, independent of a chinstrap, have been limited. One example of a protective helmet which applies earcup pressure without the use of a chinstrap is U.S. Pat. No. 4,453,277 to Durand et al. This patent discloses a helmet suitable for use by combat vehicle crewman comprising a rigid shell, formed of a ballistic resistant material, having earcup receiving extensions affixed thereto. Earcups are mounted in the shell extensions and are capable of movement in two directions thereto. The helmet also has an internal suspension system which affords two additional size adjustments.
It should be noted that the above-described protective helmet issued to Durand et al. has certain drawbacks. For example, the protective helmet offers no facial protection. Additionally, the aforementioned protective helmet has a cradle suspension system constructed of nylon straps.
Other patents of interest include U.S. Pat. No. 5.075,904 to Shirasaki et al, U.S. Pat. No. 5.056,162 to Tirums, U.S. Pat. No 4,908,877 to White, U.S. Pat. No. 4,843,642 to Brower, U.S. Pat. No. 4,778,638 to White, U.S. Pat. No. 3,409,909 to Scott et al, and U.S. Pat. No. 3,180,333 to Lewis.

The United States of America as represented by the Secretary of the Army


In a method for allocating transmission power in a communication system including multiple antennas, a plurality of subcarriers are grouped by a plurality of groups, and each group includes at least one subcarrier. A transmission power weight and an antenna transmission vector are calculated for each group by using channel information, a transmission power for each group of each antenna is calculated by using the transmission power weight and the antenna transmission vector for each group, and transmission signals are transmitted through the multiple antennas after determining which signals need to be transmitted from the multiple antennas by using the transmission power.

1. Field of the Invention
The present invention relates generally to a method and apparatus for allocating transmission power in a communication system with multiple antennas, and more particularly to a method for allocating transmission power in a communication system with an Orthogonal Frequency Division Multiplexing (OFDM) scheme.
2. Description of the Related Art
An OFDM system is applied in the Fourth Generation (4G) mobile communication system requiring large capacity of data transmission, such as Wireless Local Area Network (WLAN), wireless broadcasting and Digital Multimedia Broadcasting (DMB), in order to transmit wideband high-speed data. An OFDM system transmits operational bandwidth by dividing the operational bandwidth into several subcarriers. Specifically, an OFDM system converts inputted serial data into parallel data, and transmits the parallel data allocated to each subcarrier such that data ratio can be increased.
FIG. 1 is a diagram illustrating a conventional data transmission/receiving system employing an OFDM system.
Referring to FIG. 1, an OFDM transmission system includes an encoder 102, a Serial to Parallel converter (S/P) 104, preamble or pilot generator 106, multiplexer 108, an Inverse Fast Fourier Transformer (IFFT) 110, a Parallel to Serial converter (P/S) 112, and a Digital to Analog (D/A) converter and filter 114. An OFDM receiving system includes an Analog to Digital (A/D) converter and filter 116, an S/P 118, a Fast Fourier Transformer (FFT) 120, demultiplexer 122, preamble or pilot extractor 124, a P/S 126 and decoder 128.
The encoder 102 modulates transmission data to a modulation scheme, such as Binary Phase Shift Key (BPSK), Quadrature Phase Shift Key (QPSK), 16 Quadrature Amplitude Modulation (QAM) and 64 QAM.
The S/P 104 converts high-speed serial data to low-speed parallel data, and the preamble or pilot generator 106 creates a pilot or preamble that is loaded into transmission data. The multiplexer 108 multiplexes transmission data received from the S/P 104, and a pilot or preamble created from the preamble or pilot generator 106.
The IFFT 110 converts multiplexing signals into signals of a timing axis by using a Fourier transform, and the P/S 112 converts parallel signals into serial signals, and a Cyclic Prefix (CP) is added to a front terminal of the P/S 112.
A digital transmission signal that is converted into a serial signal by the P/S 112 can be converted to an analog signal by the D/A converter and filter 114, and the analog signal is transmitted through an antenna of a Radio Frequency (RF) terminal after passing the filter.
The transmitted analog signal is received by an antenna of the receiving system, and is converted into the digital signal by the A/D converter after passing the filter of the A/D converter and filter 116. The S/P 118 converts the serial signal into the parallel signal after eliminating a CP, and transmits the parallel signal to the FFT 120. The FFT 120 Fourier transforms the transmitted parallel signal, and then transmits the signal to the demultiplexer 122. The demultiplexer 122 demultiplexes data, and then separates data from a preamble or pilot signal through the preamble or pilot extractor 124. The parallel data signal is converted into the serial signal through the P/S 126 after the data is separated from the signal. The decoder 128 data demodulates by using a channel that is estimated by the preamble or pilot extracted from the preamble or pilot extractor 124.
When a transmission terminal of a data transmission/receiving system with an OFDM system knows channel information and uses a multiple antenna, the transmission/receiving system with the OFDM system can apply a Multi-Input Multi-Out (MIMO) precoding scheme that improves transmission efficiency by using the channel information known to the transmission terminal.
FIG. 2 is a diagram illustrating a conventional transmission block of a multiple antenna applying the MIMO preceding scheme.
An OFDM transmitter applying the MIMO precoding includes a transmission signal determination module 230 between a multiplexer 108 and a plurality of IFFTs 242, 244 and 246, a channel information module 210 connected to the transmission signal determination module 230, and an antenna transmission vector determination module 220.
The channel information module 210 uses channel reversibility as the channel information, and stores the feedback information, such as a code book index, and provides the antenna transmission vector determination module with the stored information. At this time, the channel information may be received by a group unit. The group includes "I" subcarriers that are physically consecutive, wherein "I" denotes a number between one and total number of the entire subcarriers.
The antenna transmission vector determination module 220 calculates transmission weight for each antenna in each group from the received channel information or the code book index. When the antenna transmission vector determination module 220 receives the radio channel information, it calculates the optimal transmission weight from the radio channel information. When instantaneous channel information is used for calculating the optimal transmission weight by using the radio channel information, transmission weight vector for each antenna is expressed as set forth in Equation (1):
                              w          0                =                  arg                                                                                max                                                                                        w                                                        2                                ≤                1                                                                                w                H                                                          Rw                .                                                                        (        1        )
Here, "R" is obtained by the Equation (2),R=HHH  (2)
wherein "R" denotes a covariance matrix for M×M instantaneous channel. When eigenvalue decomposition is performed from Equation (1) calculating the transmission weight vector for each antenna, transmission weight vector that maximizes receiving Signal-to-Noise Ratio (SNR) can be obtained.
When the code book is used for calculating the optimal transmission weight, a transmitter and a receiver have a predetermined code book, and the receiver obtains the optimal transmission vector and transmits the index for the vector by feedback. Consequently, an amount of the feedback information can be reduced. In addition, the transmitter determines the transmission weight for each antenna from the feedback index.
FIG. 3 is a table illustrating a conventional transmission signal for each antenna according to a code book index.
FIG. 3 is an example involving four transmission antennas, one data stream, and 3 bit code book that are indicated in the IEEE 802.16 Standard.
The transmission signal determination module 230 multiplies the transmission weight for each group
The IFFTs 242, 244 and 246 convert multiplexing signals from the transmission signal determination module 230 into signals of a timing axis by using a Fourier transform, and the P/Ss 252, 254 and 256 convert the IFFT signals into serial signals and P/S 252, 254 and 256 also add a CP. Such signals including a CP are transmitted to each antenna through the D/A converter and filters 262, 264 and 266.
However, when the transmission weight of the transmission antenna is obtained by using the channel used in the MIMO precoding scheme or when the code book is used for reducing the feedback, the weight for each subcarrier is normalized to one. In more detail, as shown in FIG. 3, the weight for each subcarrier can be represented by the following Equation (3):|v1|2+|v2|2+|v3|2+|v4|2=1  (3)
where vi denotes ith vector index of the weight for each subcarrier.
However, when delay spread exists in the OFDM system, the channel between groups may be changed.
FIG. 4 is a graph illustrating a conventional sum of antenna channel power for each group when consecutive G groups are allocated to a terminal.
As shown in FIG. 4, the sums of antenna channel power for each group are different for each group. However, since the conventional art does not use such difference of the channel power between groups, optimal transmission performance for can not be expected.
Therefore, the transmission weight for each antenna needs to be determined in considering channel condition of each group of the OFDM system in order to improve transmission efficiency.

Method and apparatus for allocating transmission power in communication system with multiple antennas

Electronics and Telecommunications Research Institute


The present invention involves an air regulation system for an internal combustion engine. The system comprises an air intake manifold, in turn presenting a main conduit with a throttle valve, and a bypass conduit with a regulating valve. An inlet and outlet are defined along the main conduit respectively upstream and downstream from the throttle valve. The system includes a device for controlling the regulating valve and sensors for detecting the speed and air intake of the engine. A processor determines the regulating valve control signal on the basis of engine speed. The processor then calculates the theoretical position of the regulating valve on the basis of engine speed and load. The processor calculates the estimated post-control position of the regulating valve on the basis of the readings of the sensors and compares the theoretical and estimated positions to generate an error signal. Finally, the processor varies the regulating valve control signal on the basis of the error signal.

The present invention relates to an internal combustion engine air intake regulating system.
As is known, motor vehicles feature an air intake manifold fitted with an air supply regulating valve--generally a throttle valve--at which is formed a bypass conduit for additional air, and the angular position of which is user-controlled either directly (accelerator pedal) or indirectly (electronic control system activated by the accelerator pedal). The bypass conduit is in turn fitted with a second valve for regulating air supply to the engine independently off the user, and which is particularly useful for supplying the engine with additional air at idling speed, startup, or when the vehicle is "braked" by the engine upon release of the accelerator pedal ("dashpot" conditions).
Known engine air intake regulating systems provide for feedback control of the air supply along the intake manifold, i.e. for continuously detecting air supply due to the angular position of the throttle, by detecting either the air pressure along the intake manifold, or the electrical resistance of a potentiometer, which is closely related to the angular position of the throttle. In most known systems, no feedback control is provided of the air supply along the bypass conduit, so that no information relative to performance and the efficiency of the adjustment effected along the bypass is supplied to the system controlling the second valve. For example, in the case of known systems featuring a step motor for controlling the second valve, air supply can only be determined by the control system on the basis of the steps commanded by it to the step motor. As step motors, however, are known, under certain conditions, to "fall out of step", thus resulting in a discrepancy --"undetected" by the control system--between the number of steps commanded and those actually performed, and since the additional air supply parameter serves for processing further engine control data, any computing errors relative to additional air supply obviously result in data processing errors.
In certain engine air intake regulating systems, the additional air supply is feedback-controlled by detecting the electrical resistance of a potentiometer, which is closely related to the position of the second valve. Such systems, however, are expensive to produce, mainly due to the cost of the potentiometer, and the difficulties posed by suitably seating and assembling it.

Internal combustion engine air intake regulating system


An arrangement for generating a digital current measurement signal includes an analog-to-digital (A/D) converter and an impedance circuit. The A/D converter is operable to receive a voltage input signal and generate a digital output signal having a digital value representative of the magnitude of the voltage input signal. The impedance circuit includes at least first and second alternative impedance values and a switch operable to cause the impedance circuit to have a select one of the first impedance value and the second impedance value. The impedance circuit is configured to receive a current signal to be digitized, the impedance circuit generating an output voltage signal representative of the current signal and having a magnitude dependent on the select one of the first impedance value and the second impedance value. The output voltage signal of the impedance circuit is then provided as the voltage input signal of the A/D converter.

Electricity meters measure electrical energy consumed by a facility. Electrical utility service providers, or simply utilities, employ electricity meters to gather energy consumption data for customer billing and other purposes. Common forms of electricity meters are electronic-based meters and electromechanical meters. Electromechanical meters employ rotating disks driven by electromagnetic fields in order to detect energy usage. By contrast, an electronic meter measures electrical energy consumption by sampling scaled-down versions of the voltage and current waveforms on the power lines of a facility and the performing energy consumption calculations using the sampled waveforms.
More specifically, electronic meters employ sensors that "scale down" the voltage and current waveforms to generate representative measurement signals. The measurement signals are then passed one or more A/D converters that sample the measurement signal to generate the "digital" voltage and current waveforms (i.e. series of digital samples). A processing circuit then performs mathematic operations on the digital voltage and current waveforms to calculate electrical energy consumption.
Electricity meters must have the ability to accurately measure currents over a broad dynamic range. While the RMS line voltage seldom varies, the RMS line current can change significantly as energy consumption by the customer changes. As a consequence, a meter must accurately measure as little as 1 Amp RMS and as much as 225 Amps RMS. This requires that the A/D converter be accurate over that same range.
This Accuracy requirement presents a problem because A/D converters inherently have less resolution when measuring quantities that are small with respect to the AID converter's range. For example, if an A/D converter having 256 discrete levels measures from 0 to 225 amps, then a small current, for example two amps RMS, will be represented by only 2 or 3 of the available discrete quantization levels. As a consequence, the digitized waveform will not have adequate resolution. By contrast, a 200 amp current waveform in the same A/D converter will be represented by well over 200 discrete quantization levels, thereby providing a fairly smooth and accurate representation of the waveform. Thus, it is difficult to obtain accurate digital representations over a broad range of current magnitudes.
Moreover, the inherent inaccuracies that exist in many A/D converters can be exaggerated when attempting to digitize signals having a peak value that is well below the effective scale of the converter. One such inherent inaccuracy of A/D converters is quantization step error. A quantization error in a converter that causes a relatively insignificant error when digitizing large input signals can cause a relatively substantial error when digitizing very small input signals.
As a consequence, to ensure accuracy over the entire dynamic range of current levels in an electricity meter, the A/D converter must be chosen such that it is highly accurate at low RMS current levels as well as at high RMS current levels. To this end, an A/D converter may include sufficient quantization step levels such that even very low current waveforms cover a number of quantization levels. Thus, it may be necessary to use an extremely high resolution A/D converter in order to ensure accuracy at low level currents. Unfortunately, increasing the number of the quantization levels of the A/D converter adds cost.
Moreover, because the excess quantization levels are not necessary at medium and high RMS current levels, the additional cost is not always justified. Nevertheless, the meter must satisfy industry and government accuracy standards over its entire useful range, including the low RMS current range.
There is a need, therefore, for an electricity meter that performs energy calculations uses digital signals, achieves accuracy over a wide range of currents, and does not suffer the cost disadvantages due to increase accuracy requirements in the A/D converter.

Switchable impedance circuit for current sensing an electricity meter


A room heating hot water boiler is disclosed in which a plurality of longitudinal rectangular hexahedral water tank groups and a plurality of lateral hexahedral water tanks are disposed in four steps above a combustion chamber in such a manner as to communicate with each other, and guide projections are formed so that an exhaustion gas discharge conduit should be provided in a zig-zag form. Consequently, the heat transfer area is increased, and convection occurs through small and large paths, so that the water of the boiler can be speedily heated, thereby improving the heat efficiency of the boiler. A lower water tank 3 and a recovering tank 3A are formed around a combustion chamber 2 of the boiler body 1. A motor pump 4 is connected between the two water tanks 3 and 3A, and a plurality of longitudinal water tank groups 3a and 3c and a plurality of lateral water tanks 3b and 3d are alternately stacked in four steps. A hot water tank 3B is formed within the boiler body 1 in communication with an upper lateral water tank 3e, and a distribution valve 7 and a recovering valve 7a are formed respectively below and outside the hot water tank 3B and the recovering tank 3A. Further, a hot water supplying tube 11 is formed on the upper portion of the hot water tank 3B.

In the prior art (Korean Utility Model Publication No. 88-2020) for which the present invention intends to improve, a plurality of longitudinal water tank groups and a plurality of lateral water tanks are disposed in two steps above a combustion chamber. A hot water tank is made to surround the longitudinal and lateral water tanks, and the lateral water tank supplies hot water to heat the rooms, while the hot water tank supplies hot water to the kitchen.
The above described conventional boiler has an advantages such that the use of the kitchen hot water is not affected by the temperature of the room heating hot water. However, the path for the convection current of water is limited within the longitudinal and lateral water tanks, and the conduit for the discharge of exhaustion gas is short. Further, heat radiating area is not large, and therefore, the thermal efficiency of the boiler is very low.


A new and distinct cultivar of Alstroemeria plant named ‘Lucy’, characterized by its compact and mounding plant habit; sturdy and strong plants; vigorous growth habit; large pink and yellow-colored flowers; and good garden performance.

The present invention relates to a new and distinct cultivar of Alstroemeria plant, botanically known as Alstroemeria hybrida, grown typically as a potted garden Alstroemeria, and hereinafter referred to by the name 'Lucy'.
The new Alstroemeria plant is a product of a planned breeding program conducted by the Inventor in Chichester, England. The objective of the breeding program is to create new compact potted garden Alstroemeria cultivars that have attractive foliage and flower coloration.
The new Alstroemeria plant originated from a cross-pollination made by the Inventor in Chichester, England in June, 2004, of a proprietary selection of Alstroemeria hybrida identified as code number T38, not patented, as the female, or seed, parent with a proprietary Alstroemeria hybrida selection identified as code number 1205/35, not patented, as the male, or pollen, parent. The new Alstroemeria plant was discovered and selected by the Inventor as a flowering plant from within the progeny of the stated cross-pollination in a controlled greenhouse environment in Chichester, England in May, 2006.
Asexual reproduction of the new Alstroemeria plant by tissue culture in a controlled greenhouse environment in Chichester, England since October, 2008, has shown that the unique features of this new Alstroemeria plant are stable and reproduced true to type in successive generations.


A luminaire housing includes a frame having a securing member, a door panel movable between open and closed positions relative to the frame, and a hinge member. The hinge member pivotally connects the door panel and the securing member and includes a fixed end portion, a first angled ramp portion, a second angled ramp portion, and a centering portion. The fixed end portion is attached to the door panel and the first angled ramp portion extends from it. The fixed end portion includes an open hinge surface. The second angled ramp portion extends from the first angled portion and the centering end portion extends from the second angled ramp portion, forming a closed hinge surface between them. The open hinge surface of the first hinge member is in contact with the securing member of the frame when the door panel is in the open position. The closed hinge surface is in contact with the securing member when the door panel is in the closed position allowing the first hinge member to be in continuous contact with the securing member when the door panel is moved between the open and closed positions.

A luminaire is a lighting unit commonly installed on a ceiling. Usually luminaire housings are formed of a host housing unit and a pivotally attached door with a lighting assembly mounted onto the door. New doors are often retro-fit to conform to existing housing units. A hinge is employed to couple the door to the housing unit for the door to pivot between open and closed positions.
Prior art host housing units commonly include a interior flange for sealing and engaging a door and coupling the door to the housing unit by a hinge member. The flange is inserted in between the door and the hinge. The hinge itself is attached to the door panel at one end and pivotally connected to the housing flange at its opposing end.
For the retro-fit door of a luminaire housing to move smoothly and precisely between open and closed positions, the door must be positioned appropriately with respect to the flange and the housing unit, and the door must not obstruct the flange itself. Prior art hinges neglect to provide a way of easily positioning the door to fit appropriately with the housing unit. As a result, the burden is on the operator to couple the door with the housing unit to ensure that the door is properly positioned.
In addition, the prior art hinges do not prevent the door from obstructing and/or damaging the flange. Specifically, if the door is hung to close to the rear flange of the housing unit, the door panel will obstruct and bend the flange downwardly upon attempting to close the door.
Examples of prior art hinges employed with a housing and door are disclosed in U.S. Pat. Nos.: 4,345,697 to Wilson et al.; and 4,308,972 to McReynolds et al.

Luminaire housing with universal dual surface cantilever hinge


An avalanche photodiode array comprising a plurality of photosensitive regions in a light sensitive body with each photosensitive region having a semiconductor junction. Between said photosensitive regions, there are a plurality of low response regions separating the photosensitive regions. A plurality of wedged shaped regions having a reflective coating on their surface are placed on the light sensitive body to cover the low response regions and to reflect incident light rays towards a photosensitive region; such incident light rays typically arriving at the photosensitive regions at angles of grazing incidence. Back reflector regions having a reflective coating on their surface are positioned about the periphery of the light entry surface to reflect light incident thereon to a photosensitive region. Placed upon the surface of the photosensitive elements is an antireflection coating comprised of a low loss material having a high index of refraction such that light rays incident on the photosensitive element at an angle of grazing incidence may deliver substantially all of their energy either to the photosensitive region so as to be detected or to the reflected rays to be reflected by the back reflector and subsequently detected, rather than having their energy dissipated by heat loss in a more lossy antireflection coating. The index of refraction of the anti-reflecting coating is approximately equal to the square root of the index of refraction of the material from which a light sensitive body is comprised.

This invention relates to quadrant arrays of photodetectors and in particular to avalanche photodiode (APD) arrays in which the transition regions between quadrant array elements are bridged by a reflective optical divider which causes radiation to be incident on photosensitive surfaces at large angles from normal incidence and in which the surfaces of the photosensitive region of the array are coated with an antireflection coating material.
Modern optical acquisition and tracking applications often require the use of a plurality of photodetectors in order to steer the boresight of the optical system toward the target. An APD array such as a quadrant avalanche photodiode (QAPD) having four photosensitive elements arranged in quadrants may be used in place of four separate photodetectors with image dividing optics to reduce the size and weight of the photodetector assembly.
Two different types of QAPD's have been developed. The first type of QAPD was a P-side divided QAPD which had a P-type light entry side contact divided into quadrants with higher resistance Pi-type material in the transition regions between the quadrants. The P-side divided QAPD suffered from several deficiencies, however, including crosstalk between the quadrants due to undepleted material in the transition region between quadrants. Additionally, the P-side divided QAPD had a significant amount of Johnson noise current due to the transition region leakage resistance which was detrimental in low bandwidth tracking applications.
Subsequently, a QAPD divided on the N-type Junction side (J-QAPD) was developed. The J-QAPD had no leakage resistance between the quadrants so that it performed better than the P-side divided QAPD in all areas except for its lack of response to signals received in the transition region between quadrants. Thus, while the J-QAPD lacked crosstalk and Johnson noise, the J-QAPD suffered from a dead zone in which carriers photogenerated by the incident light in the transition region between photosensitive quadrants were lost and did not contribute to the photodiode's output.
Numerous attempts have been made to provide an optical divider configuration which could be mounted upon the J-QAPD to bridge the dead zone and deflect light impinging upon the dead zone into a sensitive region of a quadrant, and thus provide a small effective transition region. In one approach, a mirrored prism structure with an acute angle and a very fine edge has been utilized to straddle the dead zone and deflect light into the appropriate quadrant. Typically, this mirror prism structure is comprised of silicon which has been photolithographically masked and etched to form the prism structure and coated with chrome and gold to provide a reflective surface for the impinging light rays.
The Etched Silicon Divider (ESD) forms a prism with an apex angle of 70.6 degrees which deflects the light rays at too shallow an angle for all of them to strike the underlying J-QAPD within its sensitive region. For example, rays which strike near the apex of the divider pass above the photosensitive surface and strike outside the sensitive diameter, especially near the edges. A back reflector was incorporated into the design of the ESD in order to capture the rays directed beyond the sensitive region and to deflect them downwards towards a sensitive region of the J-QAPD. While this ESD design incorporating the back reflector greatly improved the performance of the J-QAPD/ESD combination, this design still exhibited characteristic losses near the base of the reflecting prism surfaces and especially near its center along the 45 degree diagonal lines which divided each quadrant. These losses corresponded to impinging rays which hit near the base of the reflecting prism surfaces. The rays reflecting from the mirrored prism surfaces strike the sensitive region at a variety of angles and are expected to be absorbed by the photodetector or reflected toward the back reflector and subsequently photodetected. However, in prior art devices, the rays striking the sensitive region near the base of the mirrored prisms suffered unexplained losses and were thus not useful to many applications which require that all incident signal contribute to the measurement.
The impinging rays which hit near the base of the mirrored prism close to the diagonals are reflected from two intersecting faces of the mirrored wedge shaped dividers prior to striking a photosensitive region at an angle typically greater than 80 degrees form the normal. The impinging rays which hit near the base of the mirrored prism away from the center are reflected once and subsequently impinge upon the photosensitive region at an angle typically greater than 70 degrees from the normal. Rays which are incident on the mirrored prism and take one or two reflections before striking the photosensitive region arrive at very steep angles of incidence. The grazing angle of incidence at which the ray strikes the photosensitive region is typically a very large angle as measured form the normal to the surface of the sensitive region such as greater than 70 degrees. It is desirable that the rays striking the sensitive region at such a large angle would be photodetected (absorbed) or reflected toward the back reflector and subsequently photodetected. However, in prior art devices, the ray striking the sensitive region at such a large angle from the surface's normal lost a substantial portion of its energy passing through the antireflection coating upon the sensitive region and thus contributed very little to the desired output signal.
A large loss of energy by the ray striking the sensitive region at a grazing angle of incidence is typically due to the heat produced during the rays travel through the antireflection coating deposited upon the photosensitive surface. This antireflection coating has typically been silicon monoxide (SiO) which absorbs a large portion of the ray's energy and dissipates it as heat when the ray strikes the antireflection coating at such an angle so that a long path length is travelled prior to its arrival at the sensitive region. While silicon monoxide is an inefficent coating in this instance due to its inherent optical loss, silicon monoxide is generally an excellent choice for the antireflection coating material since the losses introduced are small for light rays entering substantially perpendicular to the surface of the J-QAPD.
That portion of the ray's energy reflected from the coated photodetector surface reaches the back reflector which redirects it toward a photosensitive region, however, the amount of energy delivered to the photosensitive region by this redirected ray is typically very small due to the previous dissipation of energy within the antireflection coating on the photosensitive region.
Therefore, a J-QAPD/ESD combination would be desirable which exhibited no characteristic losses along the base of the prism neither near its center along the 45 degree diagonal lines dividing the quadrants nor away from its center so that impinging light rays striking the lower portion of any prisms could effectively contribute to the output signal of the J-QAPD. Furthermore, it would be desirable for a J-QAPD to be developed having antireflection coatings comprised of a material exhibiting low loss so that substantially all the energy of the impinging light ray would reach the photosensitive region of the J-QAPD to provide a useful output

Avalanche photodiode array integrated with etched silicon divider