An object of the present invention is to provide a power amplification device having high power efficiency for an input signal even in a power region in a large back-off.

As a digital modulation system used for wireless communication in recent years such as a cellular phone and a wireless LAN (Local Area Network), modulation scheme such as QPSK and multilevel QAM are employed. QPSK is an abbreviation of Quadrature Phase Shift Keying, and QAM is an abbreviation of Quadrature Amplitude Modulation.
In these modulation schemes, generally, signals locus forms amplitude modulation when symbol transitions occur. Accordingly, the amplitude (envelope) of a modulation signal superimposed on a carrier signal of a microwave bandwidth varies over time. The ratio of the peak power to the average power of the modulation signal is referred to as PAPR (Peak-to-Average Power Ratio).
When a signal having a large PAPR is amplified, a power supply device needs to supply sufficiently large power to an amplifier so as to prevent the waveform from being distorted with peak power in order to secure high linearity.
In other words, the amplifier needs to be operated in a large back-off power region that is sufficiently lower than the saturated output power restricted by the power supply voltage.
Generally, because linear amplifiers operating in class A or class B have maximum power efficiency nearly at the saturated output power, if the linear amplifiers are operated in the large back-off region, their average power efficiency lowers.
In an orthogonal frequency division multiplex (OFDM) system using a multi carrier adopted in the next-generation mobile phones, wireless LANs and digital television broadcasts, the PAPR thereof tends to increase. Accordingly, the average efficiency of the amplifier further lowers. Note that OFDM is an abbreviation of Orthogonal Frequency Division Multiplexing.
Therefore, an amplifier has a characteristic of high power efficiency in the large back off power region is desired.
As a system that amplifies a signal in the large back-off region and with wide dynamic range and high efficiency, a power amplification device of a digital amplitude modulation system is disclosed in Patent Document 1, for example. FIG. 10 is a diagram showing a configuration of a power amplification device disclosed in Patent Document 1. As shown in FIG. 10, an amplitude signal 1050 is converted by a digitizer 1005 (A/D (Analog/Digital) converter) into n-bit digital signals 1061, 1062 . . . and 106n. The converted digital signals are inputted to n class D switching amplifiers 1011 and 1012 . . . and 101n. The class D switching amplifier amplifies a carrier signal 1052 from a RF source 1010 based on a digital signal. When logic of the digital signal which is an output of the digitizer 1005 is in High, the class D switching amplifier outputs a signal amplified by the class D switching amplifier to a power combiner 1002. When logic of the digital signal which is an output of the digitizer 1005 is in Low, an output of the class D switching amplifier is grounded.
The power combiner 1002 includes transformers 1021, 1022 . . . and 102n connected in series, and adds the output voltages of the class D switching amplifiers 1011, 1012 . . . and 101n. The voltage added signal is supplied to a load.
A block diagram of a class D switching amplifier of full bridge type which is an example of the class D switching amplifier is shown in FIG. 3. Two FETs (Field Effect Transistors) 1a and 1b and two FETs 1c and 1d which are stacked for connection are connected in parallel. One terminal of the two FETs is grounded, and the other terminal thereof is connected to a common power supply VDD.
By inputting a carrier signal 52 (S1) and an opposite phase signal (S2) thereof as shown in FIG. 3, when S1 is in High and S2 is in Low, the power supply voltage VDD appears in an output. When S1 is in Low and S2 is in High, the polarity of the output reverses, and −VDD appears. This operation is repeated and the inputted carrier signal is amplified to a signal of 2×VDD by the voltage magnitude. At that time, because the respective FETs are performing switching operation and an overlap does not occur in waveforms of current and voltage, power loss is not generated in the FETs, and amplifying with very high efficiency.
In the full bridge type class D switching amplifier shown in FIG. 3, when inputs S1 and S2 of low side FETs 1b and 1d are set to in High, respectively, and inputs S1 and S2 of high side FETs 1a and 1c are set to in Low, respectively, a voltage does not generate in an output, and the output will be in a grounding state. For example, this operation can be realized by controlling the switches 111-114 of FIG. 3.
FIG. 10 is an example in which the full bridge type class D switching amplifier shown in FIG. 3 is applied as an amplifier of a digital amplitude modulation system amplifier. When digital signals 1061, 1062 . . . and 106n are High, a carrier signal and an opposite phase signal thereof are inputted to S1 and S2 respectively. On the other hand, when digital signals 1061, 1062 . . . and 106n are Low, an output will be in the grounding state by controlling the switches 111-114. By performing voltage addition of the output with transformers 1021-102n of FIG. 10, a carrier signal to which amplitude modulation is performed can be amplified with high efficiency is possible, and can be outputted to a load.
An amplifier of a digital amplitude modulation system of such a system is utilized in a medium wave radio transmitter, and high efficiency beyond 80% is realized.
However, when a digital modulation system amplifier shown in FIG. 10 is applied to a high frequency equal to or greater than a VHF (Very High Frequency) band, two problems arise.
The first problem is caused by parasitic capacitance Cp in the FET which composes the class D switching amplifier shown in FIG. 3. That is, when the switching frequency f becomes high, power loss of the magnitude Cp·V2·f (V is voltage magnitude applied to the FET) will generate. In other words, because the magnitude of the power loss is proportional to the frequency f, when the frequency f becomes high, power loss cannot be ignored any more, and high power efficiency cannot be maintained.
The second problem is loss in transformers 1021, 1022 . . . and 102n which perform voltage addition as a power combiner. This loss cannot also be ignored any more in a high frequency domain. In particular, when a handled power is large like a base station of a mobile phone and a broadcasting station, it is difficult to realize a low-loss transformer in a high frequency domain due to the nature of a transformer.
A method to solve this problem is disclosed by patent document 2 for example. FIG. 11 is a diagram of a configuration disclosed by patent document 2.
In this system, as shown in FIG. 11, a modulated analog signal generated by a modulation signal generator 1108 is inputted to an A/D converter 1105, and is converted into a digital modulation signal. After that, the digital modulation signal is inputted to an on/off controller 1106 and converted into a control signal for turning ON/OFF (switching) four switches SW1-SW4.
Here, an example in case there are four switches SW1-SW4 is shown. There are four switches because the four switches correspond to 4 bits which are the quantifying bit numbers of the output digital signal of the A/D converter 1105.
The above-mentioned control signal switches the switches SW1-SW4 in order to correspond to respective bits. The switches SW1-SW4 receive carriers generated by a carrier generator 1110 as input signals, and input the input carriers to the power amplifiers PA1-PA4, corresponding to a period currently controlled by ON.
The power amplifiers PA1-PA4 have weighted output levels, respectively for correspondence in each bit of the 4-bit digital signal.
For example, the power amplifier PA1 has an amplification degree proportional to 23 corresponding to a most significant bit (MSB) of the 4-bit digital signal. Similarly, the power amplifiers PA2, PA3 and PA4 have an amplification degree proportional to 22, 21 and 20, respectively.
Power combining of respective output signals of the power amplifiers PA1-PA4 is performed by power combiners 1121, 1122 and 1123 provided corresponding thereto. The configuration of the power combiners 1121, 1122 and 1123 are common. That is, the power combiners 1121, 1122 and 1123 include two 3 dB couplers, a variable phase shifter and a 90° phase shifter. A diagram illustrating operation of the 3 dB coupler is shown in FIG. 8. When a signal with which 90° phase shifted in an equal amplitude (for example, magnitude is set as "1") is inputted to the 3 dB coupler, the combined power (magnitude "2") appears in an output terminal, and a power does not occur in a dummy resistor connected to an isolation terminal (magnitude "0"). That is, the 3 dB coupler can combine the power without power loss.
Next, operation of a power combiner shown in FIG. 11 is described in an example of the power combiner 1121.
According to the arbitrary bit state, a signal of the different amplitude is generally inputted to the power combiner 1121. In this case, two outputs which appear from the first 3 dB coupler M1 are equal in the intensity of the voltage vector but different in the phase. When the phases of these two signals are set to x° and y°, a voltage signal whose phase is arranged to −45° in an equal amplitude is obtained by rotating the phases only by +{(y°−x°)/2} and −){(y°−x°)/2} using phase shifters PH11 and PH12 respectively.
Two signals whose phases are shifted by 90° each other in an equal amplitude can be obtained by delaying the phase of one of the signals by 90° with the phase shifter SH1. By inputting the two signals to the second 3 dB coupler M2, the combined power appears in an output terminal, and a power does not occur in a dummy resistor R1. That is, the two signals can be combined without loss.
By performing the same operation by power combiners 1122 and 1123, and connecting the power combiners 1122 and 1123 in series, power according to the arbitrary bit state can be combined without loss.
Phase shifting of the phases of the carrier signals inputted into SW1-SW4 is performed in advance to −270°, −135°, 0° and 0°, respectively by phase devices φ1, φ2, φ3 and φ4 in order to arrange the phases of the carrier signals. After that, each of carrier signals are inputted to the amplifiers PA1, PA2, PA3 and PA4, respectively.
An advantage of this system compared with the system of FIG. 10 is that the system does not need to use a class D switching amplifier like FIG. 3, and high frequency operation becomes possible by using amplifiers of class A, class B or class C which operates as a current source. Because each of the power combiners connected to respective power amplifiers are insulated, when the amplifiers are in the on/off state, the output impedance does not need to be 0. That is, the amplifier does not need to be a voltage source. Because the amplifiers of class A, class B, or class C do not have a problem of power loss in a high frequency region as described above, high frequency operation becomes possible by using these amplifiers.
High frequency operation is also possible for a 3 dB coupler including a transmission line. Moreover, in this system, linearity of the whole amplification device does not depend on linearity of each amplifier, and each amplifier can perform only saturated operation. Accordingly, a class B-C amplifier which has high saturated efficiency can be employed as each amplifier. High efficiency can be obtained compared with a case where an amplifier which operates as a current source is used independently.
The number of the power amplifiers which operate in a small amplitude domain decreases in this system on the operating principle, and each amplifier is operating with a saturated efficiency. Accordingly, an output modulation signal amplified with high efficiency and a back off is obtained as a result.
In the related technologies of patent document 1 and patent document 2 shown in FIG. 10 and FIG. 11, the precision in an amplitude direction is decided by the number of the amplifiers, that is, the number of bits of the AD converter.
However, a signal with large PAPR is used in wireless communications such as a mobile phone, a wireless LAN, and terrestrial digital broadcasting in recent years. Therefore, the large number of bits is needed in order to obtain the desired SN ratio. For example, a digital signal of 12-14 bits is used for a signal from a baseband in a base station of a mobile phone. In order to realize the same SN (Signal to Noise) ratio in the related technology described in patent documents 1 and 2, power amplifiers of the same number (twelve to fourteen) need to be installed.
In contrast, a related technology which reduced the number of the power amplifiers is disclosed in non-patent documents 1 and 2. In these technologies, delta-sigma modulation is applied to a signal (an output of an Envelope Detector) which detected an amplitude component of an input modulation signal, and the result thereof is multiplied by a phase modulation signal (an output of Limiter and TimeDelay) of an input modulation signal. The output signal is inputted to a switching amplifier (1 bit amplifier), and output the RF output via a filter. In this configuration, the class D switching amplifier which performs switching operation is only one in a power amplifier.

Abstract: A power amplification device of the present invention includes a delta-sigma modulator which performs a multilevel delta sigma modulation on amplitude signals of input signals, a plurality of power amplifiers which amplify carrier signals, an encoder which generates a first control signal that controls ON/OFF of the outputs from said plurality of power amplifiers in accordance with the output from said delta-sigma modulator, and a combiner which combines at least two power output from said plurality of power amplifiers in accordance with said first control signal.


An electrically insulated conductor connection assembly and a method for providing the same are provided. The electrically insulated conductor connection assembly includes first and second electrical conductors each comprising a body portion and an end portion. A fastening mechanism electrically and mechanically connects the end portions of the first electrical conductor to the end portion of the second electrical conductor, and an insulator overlays and electrically insulates the fastening mechanism. The end portions of the first and second electrical conductors and the fastening mechanism form a joint, which is structured to be fastenable and unfastenable. When the joint is fastened and the insulator is overlaying the fastening mechanism, the joint is electrically insulated.

1. Field of the Invention
The invention relates generally to electrical switching apparatus and, more particularly, to conductor connection assemblies for electrical switching apparatus such as, for example, circuit breakers. The invention also relates to methods for providing electrically insulated conductor connection assemblies.
2. Background Information
Electrical switching apparatus, such as circuit breakers, provide protection for electrical systems from electrical fault conditions such as, for example, current overloads, short circuits, abnormal level voltage conditions and other fault conditions. Typically, circuit breakers include an operating mechanism having a switching device structured to open electrical contact assemblies in order to interrupt the flow of current through the conductors of an electrical system in response to such fault conditions.
For example, circuit breakers, such as power circuit breakers for systems operating above about 1,000 volts, typically employ vacuum interrupters as the switching devices. Vacuum interrupters include separable electrical contacts disposed within an insulating housing. Generally, one of the contacts is fixed relative to both the housing and to an external electrical conductor, which is electrically interconnected with a power circuit associated with the circuit breaker. In the case of a vacuum circuit interrupter, the other contact is typically part of a movable contact assembly. The movable contact assembly usually comprises a stem of circular cross-section having, at one end, the contact enclosed within a vacuum chamber and, at the other end, a driving mechanism which is external to the vacuum chamber. Power circuit breakers and vacuum interrupters therefor, are discussed in further detail, for example, in U.S. Pat. No. 6,373,358, which is incorporated herein by reference.
Electrically energized or "live" components of electrical switching apparatus must be sufficiently electrically insulated from nearby components that are electrically conductive, in order to resist undesirable electrical shorts. For example, this is particularly true in view of the market trend to design power circuit breakers to be as small and compact as possible. Specifically, the joints where electrical connections are made between components of the circuit breaker, such as between each terminal (e.g., line terminal; load terminal) and the corresponding electrical conductor (e.g., line conductor; load conductor) of the circuit breaker are one area where it is particularly difficult to achieve the requisite level of electrical insulation.
One prior proposal for providing the desired electrical insulation has been to fully encapsulate the joint in an epoxy insulation. Specifically, the joint, including the fastener(s) (e.g., without limitation, screw; bolt) that secures the joint together, have traditionally been completely covered with the epoxy insulation coating, which is molded to the joint under relatively high temperature and/or pressure, or via insulating sleeves. As the epoxy cools, it hardens, thereby forming a tight, electrically insulative bond. However, such an encapsulating approach disadvantageously makes it difficult, if not impossible, to unfasten (e.g., separate or disconnect) the individual components of the joint once it has been assembled and encapsulated. It is desirable, therefore, to provide electrically insulated conductor connection assemblies that can be relatively easily unfastened (e.g., disassembled).
There is, therefore, room for improvement in conductor connection assemblies for electrical switching apparatus, such as circuit breakers, and in methods of providing electrically insulated conductor connection assemblies.

Electrically insulated conductor connection assemblies and associated method


Optically active .beta.-halolactic acids can be produced by contacting an .alpha.,.beta.-dihalopropionic acid with 2-halo acid dehalogenase. When the pH of the reaction system is above 9, this process gives optically active glycidic acid. Treatment of the optically active .beta.-halolactic acid thus obtained with an alkali also gives optically active glycidic acid.

.beta.-Halolactic acids and glycidic acid are important as intermediates in synthesizing a variety of drugs, for example leukotriens, prostaglandins, .beta.-adrenal blockers and carnitine. In the past, most synthetic drugs were used in their racemic form, not in their optically active form. In recent years, however, several drugs have been found to be pharmacologically effective only in their optically active form while, when in racemic form, they are pharmacologically ineffective. Currently, there is an increasing tendency toward the synthesis of optically active compounds in the search for pharmacologically effective compounds. As is well known in the art, however, it is very difficult to synthesize optically active compounds by conventional methods of organic synthesis, which generally give only racemic products.
In producing optically active synthetic drugs, it is a frequent practice to produce or separate an optically active compound in an intermediate step of the synthesis and derive the final product drug therefrom. This is also the case with .beta.-halolactic acids and glycidic acid, which are important intermediates in drug synthesis, and attempts have been made to produce optically active .beta.-halolactic acids and optically active glycidic acid. Thus, for instance, in a process [process (a)] reported by Hirschbein et al. [B. L. Hirschbein and G. M. Whitesides: J. Am. Chem. Soc., 104, 4458 (1982)], optically active glycidic acid is synthesized by reducing chloropyruvic acid in the presence of lactate dehydrogenase and treating the resulting .beta.-chlorolactic acid with potassium hydroxide for cyclization.
In another process [process (b)] reported by Ohashi et al. [T. Ohashi and J. Hasegawa: Yuki Gosei Kagaku Kyokai Shi (J. Synth. Org. Chem., Japan), 45, 331 (1987); JP-A-61-268197 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"); J. Ferment. Technol., 64, 251 (1986)], 3-chloro-1,2-propanediol is microbially oxidized, followed by cyclization by treatment with potassium hydroxide, as described by Hirschbein et al.
It is also generally known that 2-halo acid dehalogenase catalyzes the conversion of an L-2-halo acid to the corresponding D-hydroxy acid [J. Biol. Chem., 243, 428 (1968); J. Eur. Biochem., 21, 99 (1971); Agric, Biol. Chem., 46, 837 (1982); JP-A-57-125690 and JP-A-57-125691]. In particular, the production of D-lactic acid from L-chloropropionic acid can be an effective method of producing optically active lactic acid from an industrial viewpoint.
Another method known for the production of optically active lactic acid starts with racemic chloropropionic acid and uses 2-halo acid dehalogenase which acts on both L-2-halo acid and D-2-halo acid (JP-A-59-31690). It is unknown whether an .alpha.,.beta.-dihalopropionic acid, which is halogenated not only on the .alpha.-position carbon atom but also on the .beta.-position carbon atom, can undergo dehalogenation only on the .alpha.-position carbon atom.
The above process (a) is disadvantageous in that an expensive coenzyme, namely NADH, must be used. Therefore, that process cannot become a commercial method for synthesizing an optically active .beta.-halolactic acid or optically active glycidic acid. To overcome this drawback, a method which used glucose-6-phosphate dehydrogenase or, in other words, a coenzyme reproduction system in conjugation, has been proposed. However, this method has so far failed to produce satisfactory economic effects and, furthermore, is disadvantageous in that the two enzymes and the coenzyme NADH coexist in the reaction system, rendering the reaction system very complicated.
Process (b) does not involves the coenzyme regeneration problem but is disadvantageous in that the yield is as low as 10 to 28%.
In conclusion, none of the known processes or methods can be said to be a commercially advantageous way of producing an optically active .beta.-halolactic acid or optically active glycidic acid.
While, as mentioned above, it is known that 2-halo acid dehalogenase acts on 2-halo acids to cause the dehalogenation, the prior art teaches nothing about the selective dehalogenation of .alpha.,.beta.-dihalopropionic acids at the .alpha.-position.

Method of synthesizing optically active .beta.-halolactic acid


A substrate composition for use in a solid phase enzyme assay for urease or in a solid phase enzyme immunoassay which includes urease as a label. The substrate composition includes a compound converted by urease to ammonia and a pH dependent reducing agent which reduces a tetrazolium salt when the pH of the medium has been raised by the ammonia produced. The tetrazolium salt may optionally be included in the substrate composition. Reduction of the tetrazolium salt produces a colored insoluble formazan which precipitates on the solid phase as an indication of the presence of urease.

1. Field of the Invention
This invention relates to immunoassay for a ligand, and more particularly relates to membrane immunoassay and particular reagents useful therein.
2. Background of the Invention
Assay systems which are both rapid and sensitive have been developed to determine the concentration of a substance, generally referred to as the analyte, present in low concentration in a fluid sample. Immunoassays depend on the binding of an antigen or hapten to a specific antibody and have been particularly useful because they give high levels of specificity and sensitivity. These assays employ one of the above reagents in labeled form, the labeled reagent being referred to as the tracer.
Enzymes have often been used as labels in immunoassay. In conventional enzyme immunoassay (EIA), an enzyme is covalently conjugated with one component of a specifically binding antigen-antibody pair, and the resulting enzyme conjugate is reacted with a substrate to produce a signal which is detected and measured. The signal may be a color change, detected with the naked eye or by a spectrophotometric technique, or may be conversion of the substrate to a product detected by fluorescence.
A convenient format for EIA is solid phase immunoassay in which one of the assay reagents is immobilized on a solid support. The solid support may be in the form of a dipstick, the inside wall of a test tube or cuvette or the well of a microtiter plate. A particularly useful solid support is a microporous membrane.
Membrane immunoassay is often referred to as flow-through assay. Examples of flow-through EIA wherein flow is generated by capillary action are the assays described in U.S. Pat. No. 3,888,629 to Bagshaw, U.S. Pat. No. 4,246,339 to Cole et al. and U.S. Pat. No. 4,632,901 to Valkirs et al. U.S. Pat. No. 4,277,560 to Gray and U.S. Pat. No. 4,812,293 to McLaurin et al. are examples of flow-through assays using pressure and vacuum respectively.
In membrane EIA, any number of liquids may be caused to flow through the membrane to effect binding, separation and washing of assay components. The final step in most membrane EIA procedures is contacting a color developing reagent, such as a chromogen, with the membrane. The chromogen reacts with enzyme captured on the membrane to produce a colored product which may be detected as evidence of the presence of analyte or measured as evidence of the concentration of analyte. The colored product may be soluble, in which case it will pass through the membrane and be detected in the filtrate, or it may be insoluble and form a colored spot on the membrane.
The enzyme urease converts urea into carbon dioxide and ammonia. It has been developed as a label for solution immunoassay wherein a rise in pH of the assay medium due to the ammonia production is detected colorimetrically with an indicator such as bromcresol purple (Chandler et al., Journal of Immunological Methods 53,187 (1982); U.S. Pat. No. 4,590,157).
EIA in which urease is detected colorimetrically in solution by the Chandler et al. procedure provides an excellent visual readout because the detected product is deeply colored and water soluble. On the other hand, rapid diffusion due to the water solubility precludes deposition of the product as a spot on a solid phase, such as a dipstick or a membrane. This severely limits usefulness of urease in solid phase EIA procedures. There is a need for a urease substrate which would be converted to an insoluble product to be deposited on a solid phase. Such a substrate would greatly extend the usefulness of urease as an immunological label. The present invention provides such a substrate.

Substrate composition for solid phase urease immunoassay


An alarm unit (1) for a vehicle comprises four magnet housings (4), each having a vehicle-engaging surface and four magnets (5) received within respective magnet housings (4) and arranged for movement relative to the vehicle-engaging surface of the housing. A spring material (11) biases the magnets (5) into a position in which they are spaced from the vehicle-engaging surface of the housing (4). An electrical sensor (10) detects movement of the magnets (5) relative to the vehicle-engaging surface of the magnet housing.

The freight industry has for years suffered loss in many forms. Some of which occurs while the vehicle carrying freight is at rest, and the driver is away from the vehicle taking a break etc. The security of the rear doors on containers being carried that contains the freight are often forced open and the security easily breached.
FR 2706830 discloses an anti-theft device for transport containers consisting of a removable casing which covers the locks or padlocks locking shut the doors of the container. This casing, connected to a central alarm, is held in place using a metal support welded or bolted onto the lock or the padlock and onto which it is applied using permanent magnets so that one or more micro-contacts are actuated as long as the casing remains in place. Withdrawing the casing actuates the alarm by releasing the micro-contacts.
This application discloses a freight protection system that has been designed to warn of intrusion. Unlike other security devices that are already in production, embodiments of this system are self-arming and completely 'stand alone' from any electrical systems on the vehicles.


A method for joining a plate chain link is to be improved, in which at least one plate is connected to at least one bolt by way of a pressing and aligning process. This is achieved by the measures that the bolt is centered in relation to a main chain axis by the simultaneous active application of symmetrical clamping forces to the faces and the least one plate is pushed by a joining lift relative to the bolt into a position symmetrical to the main chain axis. Furthermore, the invention relates to a device for carrying out the method.

The present invention relates to a method for joining a plate chain link, wherein at least one plate is connected to at least one bolt by a pressing and aligning process. Furthermore, the present invention relates to a method for carrying out the method.
In the prior art very different methods for joining a plate chain link or a plate chain have established themselves. These methods are in part quite different and are adapted to the designs of the various plate chains. There are methods in which only the inner chain links are produced and a further method is subsequently performed for joining the chain by producing the outer chain links, with the already prefabricated inner chain links being interposed. This means that the methods must be suited, on the one hand, for joining solid bolts with plates and, on the other hand, for joining hollow bolts (sleeves) with plates. In the manufacture of an outer chain link for a duplex chain a plate must e.g. first be slid in central fashion onto a solid bolt. The interposition of rollers for making a roller chain should also be possible with the individual methods.
In particular in high-quality control chains, dimensional accuracy with respect to the parallelism of the bolts (solid bolts and sleeves) and plates, the distance of the plates when several plates are used, as well as the centering of the chain link elements relative to the main chain axis, are of decisive importance.
Normally, the chain links are built up from below. This means that the lower plate is first positioned and the associated bolt is supplied. In the manufacture of an inner chain link the plate and the sleeve are then centered relative to each other via a positioning mandrel projecting from the assembly plane. Subsequently the lower plate and the sleeve are pressed together. Optionally, before or after said process a roller may additionally be mounted on the sleeve. Finally, the upper plate is supplied and also centered relative to the sleeve by means of a positioning mandrel and subsequently pressed thereonto. This procedure is carried out at predetermined cycles so that a joint press block operating with a specific lift number respectively applies the pressing force. This can be carried out on a circular table or successively in series.
DE 2 457 241 A1 already discloses a method for producing chain links on successively arranged rotary mounting tables, the method employing the layered construction of the chain link from the bottom to the top, but already effecting an excellent alignment of the individual chain link elements relative to one another thanks to the skillful use of positioning mandrels. This method, however, employs many joining steps which must be simplified. Moreover, a centering relative to a main chain axis is not fully achieved. What poses, in particular, problems are the different lengths of the bolts, so that the centering operation relative to the main chain axis is not satisfactory. It is now desirable to provide a method which with a few steps can achieve an adequate centering or symmetry of the chain links to be produced relative to the main chain axis, i.e., independently of the type of chain link (by centering a single plate in the center of the bolt or by symmetrical arrangement of two plates on the end portions of a bolt).
It is therefore the object of the present invention to provide a method and a device for joining a plate chain link which exhibits improved dimensional accuracy, in particular, with respect to symmetry in relation to the main chain axis.
According to the invention this object is achieved by providing a method for joining a plate chain link of the above-mentioned type, in which the at least one bolt is centered relative to a main chain axis by the simultaneous active application of symmetrical clamping forces to the faces of the bolt, and the at least one plate is pushed by a joining lift relative to the bolt into a position symmetrical to the main chain axis on the bolt.
The method of the invention mainly differs from the methods in the prior art by the features that while the bolts are being centered there is no action against a fixed stop, but rather a central centering operation is carried out by the simultaneous application of symmetrical clamping forces. Of particular importance is here the term xe2x80x9cactive applicationxe2x80x9d because in the prior art the force is actively applied only from one side, whereas the other side in this process is at a standstill and acts as a stop (passive application of force). The difference is now that in the prior art the dimensional accuracy, in particular, of the symmetry relative to the main chain axis is determined by the face of the chain bolt that rests-on the stop. In the present invention, the center of the main chain axis is always found in an exact way because the bolt is automatically aligned with said axis due to the active application of symmetrical clamping forces. The principle is similar to a pair of tongs in the case of which the press forces are also applied in symmetry with a line of symmetry extending through the pivot axis of the tongs. The advantage is that the chain bolts need not necessarily be produced with a very small range of tolerance, because the faces of a bolt always have the same distance from the main chain axis. This makes it also possible to simultaneously center the two bolts of a chain link in one operation if these are respectively acted upon with symmetrical clamping forces. It might be that a distinction has to be made in this method between joining lift and centering by the symmetrical clamping forces because an excellent dimensional accuracy (symmetry) is also achieved when the symmetrical clamping forces become only operative at the end of the joining operation and thereby ensure the final joining position of the bolts.
In most cases it is of advantage when the joining lift is carried out by pushing the at least one plate onto the at least one bolt and by moving the at least one plate by the simultaneous active application of symmetrical joining forces into a position in symmetry with the main chain axis. In this instance, too, the force may only be applied during the joining lift at one side of a plate as long as it is ensured that a symmetrical force couple is applied at the end of the joining lift to arrange the plates in symmetry or to center the one plate in the center. By analogy with the bolts, the plates are then also very exactly aligned relative to the main chain axis.
Furthermore, it is also possible for specific chain links that the joining lift is carried out by pushing the at least one bolt into the at least one plate and that at least at the end of the joining lift the at least one bolt is centered relative to the main chain axis by the simultaneous active application of the symmetrical clamping forces. This means in such a case that the plates are not pushed onto precentered bolts, but the at least one bolt is pushed into an opening of the plate and the bolt is subsequently centered. In such a process the plate can be fixedly anchored in its position. Such a procedure is mainly applied in the case of intermediate pin plates for duplex chains because in duplex chains the push-on paths of the bolt relative to the plate are bound to be long.
When two plates are simultaneously pushed onto the respectively opposite end portions of the bolt, this may be carried out via a corresponding centering stop on the force-applying elements, so that these occupy their symmetrical position relative to the main chain axis. Each of the outer surfaces of the plates will then have exactly the same distance from the main chain axis. Since the thickness of the plates can be produced at the same costs with a much smaller tolerance than the length of the bolts, the distance of the insides of the plates is also within the necessary range of tolerance.
Advantageously, a further method step may be provided in which the at least one plate and the bolt are prepositioned relative to one another so that an opening in the plate is arranged to be coaxial to the bolt. What should here also be called novel is the fact that independently of the number of the bolts and the plates the whole chain link can be prepositioned and can be joined in a joint centering and pressing operation. This, however, means that, in contrast to the prior art in which many lifting operations were needed for joining a single chain link, these can be carried out in a single joining station thanks to the method of the invention. On the one hand the pressing operation proper can be performed at a lower speed so that advantageous pressing conditions with less heat development are prevailing. On the other hand, the number of the manufactured parts can nevertheless be at least maintained if not even increased per time unit.
Furthermore, it may be provided that simultaneously with the application of the symmetrical clamping forces the at least one plate is guided to be coaxial to the bolt and is already pressed in part onto the bolt. As a result, the plates are centrally attached to the bolt so that no additional attaching forces have to be applied by the joining lift proper.
To apply the symmetrical clamping forces in a way that they are as coaxial to the bolt axis as possible, these can be produced by two positioning mandrels that are movable towards each other in a uniform and constant way. While the centering operation is carried out by the positioning mandrels themselves when hollow bolts are used in the case of an inner chain link, it is possible in the centering operation of a solid bolt to hold said bolt in portions in a prism for aligning the same in coaxial fashion. Such positioning mandrels can also be guided very easily and can accurately be attached to the bolt.
To enable the joining lift to apply a pressing power which is distributed as uniformly as possible around the bolt axis, the joining lift may be carried out by an upper and/or lower press block arranged around the positioning mandrels, with the press blocks applying the symmetrical joining forces. Since the positioning mandrels normally have a diameter substantially corresponding to (most of the time slightly smaller than) the outer diameter of the. bolt, the press block additionally provides a guide when the plates are pressed on. This is of enormous advantage in particular when a single plate is pressed into the center of a long bolt in a duplex-type outer chain link because the long bolt cannot deflect. It is again important that the joining lift can only be carried out by one press block when a single plate is pushed on and that the plate is aligned at the end of the joining lift by a counterpressure of the second press block.
Optionally, it may be desired that the joining lift is carried out by a positioning mandrel and that the symmetrical clamping forces for a bolt are applied by positioning mandrels that can be moved towards each other in a uniform and constant manner. This means that a bolt (sleeve) is pressed into a plate by means of the positioning mandrel and that a centering operation is only carried out at towards the end of the joining lift by the action of the second positioning mandrel from the opposite side.
Furthermore, the present invention relates to a device for joining a plate chain link. The device comprises an axially movable upper positioning mandrel and an axially movable lower positioning mandrel between which a bolt of the chain link can be positioned and clamped, a lifting mechanism by which the positioning mandrels are displaceable at a right angle relative to a main chain axis and by which active symmetrical clamping forces in relation to the main chain axis can be applied to the faces of the bolt, so that the bolt can be centered relative to the main chain axis, as well as an upper press block and a lower press block by which the at least one plate can be brought into a position in symmetry with the main chain axis or can be clamped therein.
The device is constructed such that it centers the at least one bolt of the chain link in one joining operation and pushes the at least one plate onto the bolt. The bolt can also be pushed into the plate. Furthermore, it is novel that a positioning mandrel is used for applying a clamping force. Positioning mandrels that have been used so far have mainly been used for coaxial alignment and not for the application of axial forces. In this respect it would be possible to produce a joining head according to such a principle, with the head producing a chain link by means of a single joining operation, or finishing a chain by assembling an outer chain link with interposition of an inner chain link. The alignment relative to the main chain axis forms part of the joining operation. The lifting mechanism must have a symmetrical forced coupling of the positioning mandrels. This forced coupling may also be carried out hydraulically, or pneumatically, but preferably mechanically. A principle based on some kind of tongs is here possible as a simple means of solution.
According to an advantageous development a lifting mechanism may be provided for displacing the upper and lower press blocks, by which lifting mechanism said press blocks can be displaced in symmetry with and at a right angle to a main chain axis and by which, at the same time, active symmetrical joining forces in relation to the main chain axis can be applied for performing the joining lift, so that the at least one plate can symmetrically be pushed onto the bolt. Depending on the construction of the chain link, this may be the same lifting mechanism as used for the positioning mandrels. In most cases, however, a separate lifting mechanism which is arranged in parallel therewith is used because the press blocks have to be actuated in a different way than the positioning mandrels. At any rate, this preferred and also force-coupled lifting mechanism provides for an adequate symmetry of the plates on the bolt.
In particular for the production of an intermediate pin plate for a duplex chain, the press block in a simplified version of the device may be designed as a movable and a stationary clamping jaw by which the at least one plate can be fixedly clamped in a position substantially in symmetry with the main chain axis, and the joining lift can be carried out by the at least one positioning mandrel. The press blocks are adjusted such that the plate can be clamped substantially in symmetry with the main chain axis between said blocks. In such a case the plate does then not perform a further aligning movement during the joining operation. The bolt is slid into the plate at one side and at the end of the joining lift it is centered by the symmetrical application of the clamping forces in symmetry with the main chain axis.
Advantageously, the lifting mechanism for the two positioning mandrels may comprise a joint drive with forced guidance, by which the two positioning mandrels are movable in coaxial and symmetrical fashion relative to each other. The lifting mechanism is thereby strongly simplified because a single drive moves both positioning mandrels. A forced guidance will then provide for the symmetrical conversion of the displacement path predetermined by the drive and of the displacement speed.
The lifting mechanism for the upper and lower press blocks may also comprise a joint drive with forced guidance by which the two press blocks are movable in coaxial and symmetrical fashion relative to one another. The same advantages as for the joint drive of the positioning mandrels are here observed.
When according to one embodiment the drive comprises a slide bushing which is controlled in its linear movement by a cam and which moves the positioning mandrels or the press block via a symmetrical lever linkage, it is additionally possible to combine the drive for the press blocks and the drive for the positioning mandrels because the two cams can be jointly drivable. The guidance by means of cam and controlled slide bushing is very robust and can apply the necessary forces required for pressing the chain links. Moreover, the forced guidance operates very accurately and is exactly adjustable. The centering and joining forces can be produced in symmetry by means of a few components. The lever linkage can be changed very easily, so that apart from a control by the cam there is also a possibility of adjustment via the lever linkage or the complete exchange thereof.
Moreover, at least one lever section of the lever linkage may be designed to be adjustable in its length. It is thereby very easily possible to adjust the displacement path of a positioning mandrel or of a press block. Suitable adjusting devices permit a very high precision of the adjusting operation.
The whole lift mechanism is very simplified in its structure by the measure that an overload protection means of a compressible length is provided between slide bushing and cam and/or in the lever linkage. This overload protection means also compensates for the different lengths of the bolts or the thicknesses of the plates. This means that as soon as the necessary clamping force has been applied and e.g. a further force of displacement has been exerted by the cam on the slide-bushing, said bushing cannot move further and the length of path which is additionally produced by the cam is compensated by the overload protection means. Such a possibility of compensation may also be provided at any other desired and suitable place of the lifting mechanism. For instance, the positioning mandrels and press blocks themselves may comprise suitable compression means which are compressed as soon as a specific force has been reached. This is most advantageous in the case of the positioning mandrels because the centering force would increase very strongly as soon as both positioning mandrels had been brought into contact with the faces of the bolt.
To minimize the risk of deflection of the force-applying positioning mandrels, these may be guided in coaxial bores of the press block and may be movable relative to said block. This intimate arrangement of press block and positioning mandrel also ensures an exact alignment and positioning.
To join, in particular, an inner chain link, the positioning mandrels may be providedxe2x80x94in particular according to one embodimentxe2x80x94with a cylindrical attachment which can be moved in accurately fitting fashion into the bore of a hollow bolt of an inner chain link and which defines an annular abutment step relative to the adjoining portion of the positioning mandrel which can be brought into contact with a face of the hollow bolt. The attachment thus moves into the hollow bolt and ensures a coaxial alignment in said bolt, and the abutment steps of the opposite positioning mandrels will then ensure a symmetrical centering operation relative to the main chain axis. A deformation of the face portion by the annular abutment step is not possible because of the cylindrical attachment.
Furthermore, the positioning mandrel may comprise a centering portion which can removed into the opening of the plate and aligns said plate such that it is coaxial to the hollow bolt. Thus the plate is also aligned by the positioning mandrel in an exact manner before said plate is pushed onto the bolt. This, however, means that the supply means must just ensure a prepositioning operation within a wide range of tolerance and the centering operation proper is carried out by the positioning mandrel. The feeding operation is also facilitated by this measure to a considerable degree.
To compensate for diameter tolerances of the opening in the plate, one variant provides that the centering portion has a frustoconical shape. A centering operation is thereby carried out at any rate, i.e. independently of the size of the opening within the tolerance zone.
In addition it has been found that the whole joining operation can be made more precise and improved in that the centering portion and the abutment step are designed such that a slight joining lift can be carried out by the positioning mandrel for the attachment of the plate to the outer surface of the hollow bolt before the abutment step rests on the face of the hollow bolt. The position of the abutment step and the length of the centering portion as well as the shape thereof are adapted to the opening, in particular the thickness of the plate, such that a corresponding attaching operation is carried out. For instance, the plate can already be pushed with one quarter onto the bolt by said operation. Of course, it is also possible to move the positioning mandrel in parallel with the press block in said portion so that the actual application of the force is mainly carried out by the press block and the positioning mandrel just assumes the centering task during the attaching operation.
For a pressing operation over a surface of the plate that is as large as possible, the press blocks in one embodiment comprise a press block surface which surrounds the associated positioning mandrel and is substantially arranged in planar and vertical fashion relative to the mandrel axis and is displaceable relative to the positioning mandrel and presses the plate onto the outer surface of the hollow bolt. Tilting forces on the plate are avoided because the plate rests on the press block surface over a large surface thereof.
Furthermore, the upper and/or lower press blocks may comprise an extension which during the joining lift stops its movement and defines an exact joining distance of the press block surfaces relative to each other at the end of the joining lift. This makes above all sense when two plates are to be pushed onto the end portions of a bolt. The extension then defines the distance of the two plates relative to one another so that the plates, although they are pushed on in symmetrical fashion, leave an exactly defined distance thereinbetween. As for extensions which are arrested and stop their movement, an overload protection means may be of advantage.
For most of the chain links it is desirable to produce the same in a single joining operation. This fact is best taken into account according to one embodiment in that two upper positioning mandrels and two lower positioning mandrels are respectively arranged for forming a joining head in a jointly associated upper and lower press block. Such a joining head compensates for variations in the lengths of the two bolts. A compensation in the plates is not needed because it must be assumed that one plate does not vary in its thickness. This results in a very simple and compact construction which fully meets the demands made on the joining operation.
Advantageously, a supply means is provided which prepositions all elements of a chain link and supplies the same in a prealigned manner to a joining head. This is also novel because so far individual parts have most of the time been supplied separately and have then been connected at a corresponding joining place to the already prealigned components. The prepositioning and feeding operations for all elements at one time, i.e. all components are interconnected by a single joining operation, have so far not been carried out in the prior art with such a quality.
The device according to the invention is able to finish the chain link in a single joining operation. So far chain links have always been of a layered structure, with a joining lift being again performed in each layer. It has in particular been the objective of this invention to provide a method and a device in which a press fit can be accomplished in one single operation, even in the case of intermediate pin plates for duplex chains. A subsequent alignment or further displacement of the plates and bolts relative to one another, which would always entail a weakening of the press fit, is avoided. The device can operate at relatively low joining speeds because relatively small lifts have to be produced in the joining head, and nevertheless a higher output of chain links can be achieved because the joining steps have been reduced to a single joining operation. Moreover, this is a forced assembly in which all components are force-guided during the joining operation. The components can thus be aligned with one another in a very precise way.

Method for joining a flat-link articulated chain element

Joh. Winklhofer and Sxc3x6hne GmbH and Co. KG.


A heater body or a circulation path for a heating gas is provided in an inner surface of a lid body that opens and closes an opening portion of a process tube. The circulation path is formed in such a manner that it passes through a gap between the lid body and the shaft of a rotation mechanism that rotates a quartz boat holding semiconductor wafers within the process tube. A heating gas at a temperature at least as high as the vaporization temperature of reaction products is made to circulate through this circulation path. Since the inner surfaces of the lid body are heated, reaction products do not adhere to the inner walls of the lid body and the lower portions of the process tube. Since there no source of contamination is generated thereby, the semiconductor wafers and the clean room are not contaminated. Since the circulation gas is made to flow in the reverse direction in the gap, there is no leakage of reaction gas therefrom. Thus the clean room is not contaminated and semiconductor wafers can be fabricated with a good yield.

The present invention relates to a thermal treatment apparatus and, in particular, to a thermal treatment apparatus used in the process of fabricating a semiconductor device.
During the conventional process of fabricating a semiconductor device, an apparatus such as a CVD apparatus, oxide film formation apparatus, or diffusion apparatus is used to perform an operation such as form a film or an oxide layer on a semiconductor wafer, or implant impurities. One such apparatus is a thermal treatment apparatus wherein semiconductor wafers are inserted into a reaction vessel by means such as a quartz boat capable of holding a plurality of semiconductor wafers horizontally, and a treatment is performed thereon by a reaction gas introduced into the reaction vessel that has been heated to a high temperature. This thermal treatment apparatus can be used in many different ways to simultaneously and rapidly treat a plurality of semiconductor wafers, by adjusting the temperature and heating.
However, as semiconductor devices have become smaller and also the diameters of semiconductor wafers have increased, there is demand for forming an ultra-thin film on a semiconductor wafer of a large area. The thermal treatment apparatus can perform batch processing in which a plurality of semiconductor wafers are processed at the same time, but unevenness in processing can easily occur between the central and peripheral portions of the same semiconductor wafer, and between semiconductor wafers at different positions within the thermal treatment apparatus. Various improvements have been proposed in the past to prevent this unevenness.
A thermal treatment apparatus of the above type is provided with a vertical cylindrical process tube made of a heat-resistant material such as quartz, and heaters for heating the interior of the process tube to a high temperature of 900.degree. C. to 1200.degree. C., or even higher, are arranged around the process tube. The lower part of the process tube is formed as an opening through which a heat-resistant quartz boat in which a plurality of semiconductor wafers are supported horizontally can be conveyed. The opening is provided with a lid body that has a contrivance such as an 0-ring for maintaining the interior airtight. The lid body is supported by a support body that is connected to an elevator drive mechanism with coil springs therebetween, so that the opening of the process tube can be opened and closed thereby. A heat-insulating tube is provided in the lid body, and the entire body of the quartz boat that supports the semiconductor wafers mounted on the heatinsulating tube is positioned in a flat heating zone of the process tube in such a manner that the semiconductor wafers are heated uniformly and are thus treated uniformly. In addition, a circulation path for cooling water is provided in the lid body so that the lid body is cooled and thus apparatuses below the process tube are prevented from being heated.
In order to introduce reaction gas into this process tube, a reaction gas introduction pipe connected to a reaction gas supply body is provided from below the process tube to an upper portion thereof along to the inner wall, and the reaction gas which is heated while it is passing through the introduction pipe is supplied from a supply opening provided .in an upper portion of the process tube. The arrangement .is such that reaction products created while the semiconductor wafers are being treated are discharged from an exhaust opening which is provided above the process tube and is connected to an exhaust apparatus, together with excess reaction gas.
The thermal treatment apparatus configured in this manner is also provided with a rotation mechanism that rotates the quartz boat of semiconductor wafers to ensure that the treatment effected within each semiconductor wafer is uniform. The rotation mechanism is configured so as to support the heat-resistant tube on a shaft connected to a motor shaft provided on the outside of the process tube.
Unfortunately, reaction products tend to adhere to the lid body and the inner wall at the bottom of the process tube of this conventional thermal treatment apparatus. In particular, when a doping gas such as POC1.sub.3 is used in a diffusion apparatus, phosphorous glass fused from phosphorous and SiO.sub.2 cannot be prevented from depositing on these areas. There is a danger that adhered substances layered in this way may later peel off and fly into the process tube, contaminating the semiconductor wafers and deteriorating the yield thereof. The adhered substances may also peel off while the semiconductor wafers are being conveyed into or out of the process tube, forming a source of contamination of the clean room.
If the thermal treatment apparatus is provided with a rotation mechanism, there is the danger that reaction products may adhere in the small gap which is formed between a hole in the lid body and the rotational shaft connected to the shaft of the motor, and which is necessary to allow rotation. In the worst case, the reaction products may peel off while the quartz boat is rotating, to form contamination sources.

Thermal treatment apparatus utilizing heated lid


A reimager comprises precisely two positive lenses wherein the chromatic longitudinal aberration lies within the depth of focus and the thermal image position variation likewise lies within the depth of focus over a temperature range of more than .+-.30.degree. (in the embodiment from -40.degree. C. to +70.degree. C.). Aspheric and diffractive surfaces are utilized and, if required, are joined on respective lens surfaces (31, 51, 53, 71, 73).

A solution having suitable chromatic and thermal correction for thermal image apparatus in the spectral range from approximately 7.5 .mu.m to 10.5 .mu.m and only four to five lenses is disclosed in United States patent application 08/780,295, filed Jan. 8, 1997, incorporated herein by reference. Here, chalcogenide glasses and aspheric surfaces are provided.
U.S. Pat. No. 5,044,706 discloses a telescope suitable for the same use. An intermediate image is provided with four lenses for the far viewing field. Thus, a reimager is provided. A telescope without an intermediate image is realized with only two lenses thereof. The front lenses both have aspheric surfaces on different sides and a diffractive kinoform surface. Nothing is suggested as to athermalization.

Achromatized and athermalized two-lens reimager


A method is disclosed for adaptively updating full or partial singular value decomposition (SVD) of a transfer matrix. The method employs orthogonal projections of known output and input vectors onto initial estimates of left and right singular vectors to compute corrections to the initial estimates of the singular vectors and singular values and adaptively generate updated estimates thereof. The method can be used for MIMO systems, including system of wireless MIMO communications employing adaptive transmitter and V-BLAST techniques.

Singular value decomposition (SVD) of a matrix is a powerful mathematical tool used in many applications involving data processing, including data mining, dynamic system control, and communication systems. In particular, SVD is advantageously used in MIMO systems to determine orthogonal input-output channels over which information can be transmitted independently and without inter-channel interference, or to determine weight vectors and symbol detection order in systems employing successive interference cancellation. In some cases when the matrix in question changes in dependence on a parameter, e.g. time or frequency, the SVD of the matrix has to be repeatedly updated. Since conventional methods of SVD computation can be fairly complex and time-consuming, developing simplified and effective SVD update algorithms is of considerable practical significance.
A wireless MIMO communication system, wherein multiple transmit and receive antennas are used to increase capacity and combat multi-path interference and channel fading during transmission of information, is an important example of an application, which can benefit from efficient SVD update algorithms.
In a typical MIMO communication system having K>1 antennas at a transmit site and M>1 antennas at a receive site, each receive antenna can detect signal energy from each of the K transmit antennas, thereby providing K×M interfering signal paths between the receiver and the transmitter. Signal transmission in this system is commonly described by a matrix equationr=Hs+ν  (1)where s is an input vector of length K with element si representing an information signal emitted by the ith transmit antenna, r is an output vector of length M with element ri representing a signal sample detected by the ith receive antenna, ν is a length M noise vector accounting for transmission and receiver noise, and H is a transfer matrix of size M×K accounting for multi-path interference and other linear transmission effects affecting the signal. The transfer matrix H of a MIMO wireless channel can change with time and in dependence on channel frequency.
SVD of the transfer matrix H has the formH=VΣUH.  (2)
Columns of the unitary matrices V=[v1 . . . vM] and U=[u1 . . . uK] are commonly referred to as left and right singular vectors vi and ui, respectively, corresponding to singular values σi. The M×K matrix Σ has the singular values σi as its diagonal elements, i.e. Σii=σi for i=1, . . . , min(M,K), with all other elements equal to zero. The superscript [ ]H in equation (2) denotes the complex conjugate transpose operation.
The left and right singular vectors form two orthogonal sets of vectors, which define M-dimensional receiver and K-dimensional transmitter spaces, respectively, with M typically equal to or exceeding K. Transmission of a jth right singular vector by the transmitter results in the reception of the jth left singular vector scaled by a gain coefficient equal to the jth singular value σj and some additive noise:s=ujr=σjvj+νj.  (3)
Therefore, knowledge of the SVD of the transfer matrix enables the establishment of up to K orthogonal independent communication channels between the receiver and the transmitter, and the deciphering of the transmitted signal at the receiver site. If the transfer matrix changes with time, or e.g. with frequency, the SVD needs to be periodically updated to maintain channel orthogonality and avoid inter-channel interference.
U.S. Pat. No. 6,760,388 issued to Ketchum, et al. discloses a wireless MIMO system employing the SVD at the transmitter to determine eigen-modes, i.e., spatial subchannels, of the MIMO channel and to derive a first set of steering vectors used to "precondition" modulation symbols. The SVD is also performed at the receiver to derive a second set of steering vectors used to precondition the received signals, such that orthogonal symbol streams are recovered at the receiver. The MIMO system taught by Ketchum, as well as some other prior art MIMO systems employ conventional algorithms of SVD processing. These algorithms typically require computation of the full SVD and have complexity of at least O(M3), i.e. the number of multiplications they require grows as M3 as M increases, which may not be feasible for real-time implementation in applications requiring frequent updates when M is large.
In many applications, the MIMO channel and the corresponding transfer matrix changes slowly, so that the sets of the singular vectors do not change much between consecutive updates. Therefore, instead of performing a full SVD computation each time an SVD update is required, tracking techniques may be employed when the singular vectors and singular values at an nth step are found using known singular values and singular vectors determined at the (n−1)th step. In many cases, for example when some of the singular values are too small for reliable detection, only a subset of the singular vectors and singular values needs to be updated; such periodic updating of a subset of the singular vectors is sometimes referred to in the art as subspace tracking.
However, most prior-art subspace tracking techniques are based on eigenvalue decomposition (EVD), wherein only the left singular vectors vj, which are the eigenvectors of a covariance matrix R=E{rrH}, where E{} denotes math expectation, and its eigenvalues □j=σj2 are computed. Estimates of the right singular vectors can be then obtained by inverting the SVD equation (2) requiring again a matrix multiplication of complexity O(M3). A summary of the subspace tracking techniques is given in H. Krim and M. Viberg, in an article entitled "Two decades of array signal processing research," IEEE Signal Processing Mag., vol. 13, pp. 67-94, July 1996.
A method for updating the right singular vectors and eigenvalues, i.e., the eigendecomposition of Rr=HHH+ωn2I, was disclosed in an article by A. Kav{hacek over (c)}ić and B. Yang entitled "A new efficient subspace tracking algorithm based on singular value decomposition," Proc. ICASSP, pp. 485-488, April 1994. However, the Kav{hacek over (c)}ić method does not provide the left singular vectors, which again can be computed from equation (2) requiring a matrix multiplication of complexity O(K3), which can be unacceptable for applications requiring frequent updates.
B. Banister and J. Zeidler, in an article entitled "Feedback assisted transmission subspace tracking for MIMO systems," IEEE Sel. Areas Commun., vol. 21, pp. 452-463, May 2003, disclosed an adaptive algorithm for use in MIMO wireless communication systems, wherein weight arrays are used at the transmitter and the receiver for establishing the orthogonal communications channels. The weight arrays are periodically jointly updated to adapt to changing transmission conditions. The Banister method requires computation of a binary feedback decision, which is used to increment or decrement the transmitter weight array. Furthermore, this method has an advantage of low feedback throughput requirements, at the cost of complexity at the transmitter and receiver; it requires at least one matrix multiplication at the receiver, as well as one matrix addition and a Gram-Schmidt orthogonalization at the transmitter, and has the complexity of at least O(M3).
An alternative MIMO transmission techniques commonly referred to as V-BLAST uses a cancellation and nulling scheme requiring multiple instances of Moore-Penrose pseudo-inverses of a modified channel matrix H+ also requiring SVD computations:H+=U ΣVH  (4)where the elements of Σ are given by
                                          σ            _                    i                =                  {                                                                      1                  /                                      σ                    i                                                                                if                                                                                σ                      i                                                        >                  0                                                                                0                                                              otherwise                  .                                                                                (        5        )
This approach is described e.g. in an article by G. Golden, G. Foschini, R. Valenzuela, and P. Wolniansky, entitled "Detection algorithm and initial laboratory results using VBLAST space-time communication architecture," Elect. Lett., vol. 35, January 1999, and is also taught in U.S. Pat. No. 6,763,073 issued to G. J. Foschini and G. D. Golden. In a time-varying application, this approach would also benefit from a low-complexity SVD update method applied to update the matrix inverses as H+ changes.
It would be therefore advantageous for a number of applications to have a low-complexity method of updating the SVD of a slowly-varying or fixed transfer matrix.
An object of this invention is therefore to provide such a low-complexity method of updating left and right singular vectors and singular values of an SVD of slowly-varying or fixed transfer matrices using known information of input and output vectors.
It is another object of this invention to provide a low-complexity method of partial SVD updating for slowly-varying or fixed transfer matrices, wherein only some left and right singular vector pairs are updated together with their corresponding singular values.

Method for updating singular value decomposition of a transfer matrix

Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, Through the Communicatios Research Centre Canada


Viterbi trellis coding methods and Viterbi detector apparatus are provided for detecting trellis coded data. A systolic array Viterbi detector recursively calculates path metrics and partial sums of metric update equations to determine codeword sequences having minimum mean squared error for Viterbi-type maximum-likelihood data detection. The systolic array Viterbi detector is arranged to eliminate redundant calculations and simplify hardware requirements. Modified butterfly trellis geometries and rotating state metrics arrangements are provided for simplifying the Viterbi detector.

1. Field of the Invention
The invention relates generally to Viterbi trellis coding methods and apparatus, and more particularly to Viterbi trellis coding methods and apparatus for partial-response maximum-likelihood (PRML) data channels in a direct access storage device (DASD).
2. Description of the Prior Art
Computers often include auxiliary memory storage units having media on which data can be written and from which data can be read for later use. Disk drive units incorporating stacked, commonly rotated rigid magnetic disks are used for storage of data in magnetic form on the disk surfaces. Data is recorded in concentric, radially spaced data information tracks arrayed on the surfaces of the disks. Transducer heads driven in a path toward and away from the drive axis write data to the disks and read data from the disks. Partial-response signaling with maximum-likelihood sequence detection techniques are known for digital data communication and recording applications. Achievement of high data density and high data rates has resulted in the use of a PRML channel for writing and reading digital data on the disks.
U.S. Pat. No. 4,786,890 discloses a class-IV PRML channel using a run-length limited (RLL) code. The disclosed class-IV partial response channel polynomial equals (1-D.sup.2), where D is a delay operator and D.sup.2 is a delay of 2 bit times and the channel response output waveform is described by taking the input waveform and subtracting from it the same waveform delayed by a 2 bit interval. A (0,k=3/k1=5) PRML modulation code is utilized to encode 8 bit binary data into codewords comprised of 9 bit code sequences, where the maximum number k of consecutive zeroes allowed within a code sequence is 3 and the maximum number k1 of consecutive zeroes in the all-even or all-odd sequences is 5.
Trellis coding techniques are used to provide a coding gain required in noisy or otherwise degraded channels. U.S. Pat. Nos. 4,888,775 and 4,888,779 describe trellis codes for PRML channels which provide significantly improved coding gains for transmission of digital data over PRML channels.
There is a need for improved Viterbi trellis code detectors that provide coding gains and bit rates required for transmission of digital data over PRML channels while reducing the number of calculations involved in the Viterbi algorithm, and reducing and simplifying the required digital hardware.

Viterbi trellis coding methods and apparatus for a direct access storage device

International Business Machines Corporation


Examples disclosed herein relate to classification models for binary code data. Some of the examples enable obtaining changed binary code data and unchanged binary code data, and generating, using a machine-leaning algorithm, a classification model based on training data that comprises the changed binary code data and the unchanged binary code data.

Source code represents any collection of computer instructions written in a human-readable computer language such as text that can be easily written and understood by a human. Software developers may develop a software program by writing source code which specifies the actions to be performed by a computer. The source code may then be transformed by a compiler program into low-level machine code (e.g., binary code) understood by the computer.

Classification models for binary code data


A dish for use in a manhole having a manhole cover covering a manhole opening and a frequency transmitting system for use in a manhole are provided. The dish and the frequency transmitting system is configured to transmit a signal to a network through the manhole cover. The signal is generated by a sensor unit disposed within the manhole and configured to detect the conditions of the manhole.

Modern cities operate in part using a maze of subterranean utility lines such as water, steam, and sewer lines. However, despite the importance of these utilities, the only device that typically stands between the person gaining access to a subterranean line or conduit is a simple iron or steel manhole cover. These manhole covers are dimensioned to fit within a manhole opening. However, they are generally smaller in diameter so as to allow a user to remove the manhole cover to gain access to the subterranean utility.
It is desirable to identify instances where unauthorized access to the subterranean utility has occurred or when volatile gas is present within the manhole. Proximity sensors and fume sensors may be used to detect such conditions. However, transmitting a signal out of the manhole is difficult as the manhole cover may become a barrier preventing a signal from reaching a carrier network. Accordingly, it remains desirable to have a dish configured to utilize the manhole cover to assist in transmitting a signal generated within the manhole, out of the manhole.


The invention is directed to transgenic plants transformed with nucleic acids that encode a plant transcription factor that increases the transgenic plant's size and yield and/or delays flowering in the plant, and methods of using and producing the transgenic plants.

Transcription factors can modulate gene expression, either increasing or decreasing (inducing or repressing) the rate of transcription. This modulation results in differential levels of gene expression at various developmental stages, in different tissues and cell types, and in response to different exogenous (e.g., environmental) and endogenous stimuli throughout the life cycle of the organism.
Because transcription factors are key controlling elements of biological pathways, altering the expression levels of one or more transcription factors can change entire biological pathways in an organism. For example, manipulation of the levels of selected transcription factors may result in increased expression of economically useful proteins or metabolic chemicals in plants or to improve other agriculturally relevant characteristics such as to increase yield. Therefore, manipulating transcription factor levels in a plant offers tremendous potential in agricultural biotechnology for modifying a plant's traits such as improved yield from commercially important plant species.
One factor affecting yield is the number of plants that can be grown per acre. For crop species, planting or population density varies from a crop to a crop, from one growing region to another, and from year to year. Using corn as an example, the average prevailing density in 2000 was in the range of 20,000-25,000 plants per acre in Missouri, USA. A desirable higher population density (a measure of yield) would be at least 22,000 plants per acre, and a more desirable higher population density would be at least 28,000 plants per acre, more preferably at least 34,000 plants per acre, and most preferably at least 40,000 plants per acre. The average prevailing densities per acre of a few other examples of crop plants in the USA in the year 2000 were: wheat 1,000,000-1,500,000; rice 650,000-900,000; soybean 150,000-200,000, canola 260,000-350,000, sunflower 17,000-23,000 and cotton 28,000-55,000 plants per acre (Cheikh et al. (2003) U.S. Patent Application No. 20030101479). A desirable higher population density for each of these examples, as well as other valuable species of plants, would be at least 10% higher than the average prevailing density or yield.
The present invention provides novel transcription factors useful for modifying a plant's phenotype in desirable ways.

Transcription factors for increasing yield


A parallel processing system having a number of processing nodes (S1 . . . Sn) each of which is provided with a message handling kernel (13 . . . n3) and an associated procedure register (14 . . . n4), the procedure registers being loadable by loading means (4) under the control of an application (3) and the nodes being able to exchange messages over a message interface (2) and to process messages to determine the message handling procedures to be invoked by the associated node in accordance with the contents of the associated procedure register.

While these advantages can readily be achieved where sets of data to be processed by the processing units or nodes are independent, a problem arises when the result of processing in one or more nodes affects the processing operations taking place in another node or nodes.
If, for example, code is written to perform in parallel what has hitherto been an essentially serial operation, the dependencies between the various parallel operations may become extremely complex, to the point where the analysis of potential conflict can be prohibitively difficult. The code may require a great deal of testing and corrective procedures in order to deal with the synchronising messages which are necessarily exchanged between parallel strands of an application program.
Such a situation can arise in the analysis of the substantial quantities of data, extending to many millions of records, obtained in commercial activities such as insurance and retailing. Speedy analysis is essential if marketing strategy is to be effectively and flexibly matched to customer needs and preferences, and a number of processes have been developed to recognise marketing trends in order to respond effectively thereto.
In one such process, referred to as data mining, records are analysed serially to develop a model which can be used for predicting trends. The model is dynamically updated as the analysis proceeds, and each processing step is required to be taken in accordance with the model that is current. Data mining has accordingly been traditionally performed as a serial, single processor operation. This is necessarily a computationally intensive process, and considerable advantage could be gained by the application of parallel processing techniques to processes such as data mining.

Parallel data processing system and method of controlling such a system


A rasterizer is used with a system capable of furnishing raster data representative of a string of characters to be formed on a display. The rasterizer has an input interface that is connected to receive the raster data from the system. A graphics engine is connected to use the raster data to simultaneously store representations of portions of at least two of the characters in a memory. An output interface is connected to use the representations stored in the memory to form an output signal which is used by the display to form the characters.

The invention relates to generating text strings.
As shown in FIG. 1, to display a text character (e.g., an "h" 17) on a display 16, a central processing unit (CPU) 25 of a computer system 12 typically generates both monochrome raster data 11 defining the character and an address specifying the location on the display 16 at which the character should appear. A rasterizer 14 uses the raster data 11 and address to generate analog signals (e.g., RGB signals) which cause the character to appear at the desired location on the display 16.
As shown in FIG. 2, the raster data 11 directs the placement of foreground pixels (each pixel having a predetermined foreground color) of the character on the display 16 by defining a bit mask for a corresponding block 23 of pixels. One bit value (e.g., a logical one) sets the color of a corresponding pixel equal to a predetermined foreground color, and another bit value (e.g., a logical zero) leaves the color of the corresponding pixel unchanged (i.e., the background of the character is transparent). The size of the character (i.e., the width (in pixels) and height (in pixels) of the pixel block 23) is a function of a user selected character size, and the particular mask defined by the raster data 11 is a function of a user selected font.
The rasterizer 14 typically has a graphics engine 10 (FIG. 1) which stores a color value (e.g., a sixteen bit representation of the color of a pixel) for each foreground pixel of the character in a frame buffer 13 (FIG. 3). The frame buffer 13 typically is organized by subregions 30 with each subregion 30 containing color values (representative of foreground and background pixel colors) associated with a horizontal scan line (typically one pixel high and 1024 pixels wide) of the display 16. Thus, a character to be displayed is stored in a region 31 of the frame buffer 13 that includes portions of several subregions 30 (i.e., the character is drawn using several scan lines). As an example, for a character having a width of four pixels and a height of nine pixels, one subregion 30a contains four color values associated with the top line of the character, and one subregion 30b has four color values associated with the bottom line of the character. A digital-to-analog converter (DAC) 21 regularly receives the color values from the frame buffer 13 and uses the color values of each subregion 30 to generate one of the scan lines.
The rasterizer 14 typically draws a text string (e.g., a string "hello" 27 in FIG. 1) on the display 16 one character at a time. For example, to draw the string "hello," the graphics engine 10 first transfers the color values associated with the character "h" to the display 16. As a result, the character "h" appears on the display 16 (FIG. 4A). Next, the graphics engine 10 transfers the color values associated with the character "e" to the frame memory 13. As a result, the character "e" appears on the display 16 (FIG. 4B). The graphics engine 10 continues this process until all color values associated with the string are stored in the frame buffer 13, and as a result, the entire string appears on the display 16.
The memory cells of the frame buffer 13 typically are arranged in rows (often referred to as pages) and columns. Before one of the rows is accessed (read from or written to), the row must be precharged which introduces a delay (often referred to as a page fault delay) in accessing the row. Due to this required precharging, successive accesses to the same row (i.e., accesses that remain in the same page) require less time than successive accesses to different rows (i.e., no page fault delays for successive accesses to the same row).
The graphics engine 10 typically has to access several different pages in the frame buffer 13 to transfer the color values for one character. As an example, for a sixteen bit color value and a page size of four kilobytes, only the color values associated with two lines of the character are contained within one page (i.e., only two subregions 30 per page). As a result, when transferring the color values for a character to the frame buffer 13, the graphics engine 10 must access a different page (i.e., a page fault delay is introduced) for every two lines of the character.


In a method of generating and/or executing a diversified program flow from a program source code for or on at least two processing units of a machine tool, production machine or robot, a machine code is generated from a program source code by a compiler for at least one processing unit with a programmable processing module. The program source code is also used to generate by a converter or interpreter a description file which is run interpretatively in at least one further processing unit by at least one programmable processing module. Data of the processing units is saved in at least one common memory and checked for a match through respective data comparison.

The present invention relates to a method of generating and/or executing a diversified program flow from a program source code for or on at least two processing units of machine tools, production machines and robots.
Security zones are normally established in order to protect machines, production goods, persons against dangers in the security zone of machines or the like, and monitored, e.g. by sensors. A logical interconnection structure, related to the safety aspects of the machine and based on a programmable control, executes a defined action when the security zone is violated. The safety-related actions may involve, for example, a shutdown, certain operations in case of emergency, slowdown, position restrictions, etc. Hereby, the safety-related actions or security functions include system manipulations that may even involve the electric drives and measuring systems. A reliable function of secure operational modules in executable programs is hereby essential.
To ensure clarity, it is necessary to establish the definition of several important terms and expressions that will be used throughout this disclosure. The term "safety-related" designates hereby the recognition and managing of systematic and random errors, as well as failures. This can be realized, e.g., by the use of diversity in connection with computer systems or control systems of machine tools, production machines and robots, whereby the diversity involves the establishment of, e.g., several programs which satisfy the same specification. A comparison of the events, computed by the individual program variants, enables hereby a recognition of permanent and transient hardware errors in addition to the recognition of errors in design.
Typically, a logic program is used which involves redundant-parallel processing and cyclical comparison of results. When a deviation of the computed results has been ascertained, a secure state of the machine or of machine parts is immediately initiated.
It would be desirable and advantageous to provide an improved method of generating and/or executing a diversified program flow from a program source code.

Method of generating and/or executing a diversified program flow


An apparatus and method to recognize a user's emotion based on emotional segments are provided. An emotion recognition apparatus includes a sampling unit configured to extract sampling data from input data for emotion recognition. The emotion recognition apparatus further includes a data segment creator configured to segment the sampling data into a plurality of data segments. The emotion recognition apparatus further includes an emotional segment creator configured to create a plurality of emotional segments that include a plurality of emotions corresponding to each of the respective data segments.

1. Field
The following description relates to an apparatus and method to recognize a user's emotion and provide an appropriate service according to the user's emotion.
2. Description of the Related Art
A user's emotion has been estimated based on direct information, such as the user's look or voice, from which the user's emotion can be directly recognized. In addition, a user's emotion has been estimated based on indirect information, such as the user's behavior pattern.
In recognizing a user's emotion at a specific time, a sufficient amount of successive data may be essential for a more exact recognition. However, there may be difficulties in accurately interpreting a user's emotional state from given data since a human's emotions tend to become complicated and often change. Moreover, data about successive direct/indirect human behaviors can include certain noise that may cause performance deterioration in emotion recognition.

Apparatus and method for recognizing emotion based on emotional segments


A femoral component of a knee prosthesis, including a cobalt-based alloy substrate and a titanium fiber metal pad bonded thereto by means of an interlayer of a cobalt-based alloy including nickel. More specifically, a method of bonding a titanium porous surface to a cobalt-based alloy in an orthopaedic implant device, by first applying an interlayer of a cobalt-based alloy including nickel to the substrate and then bonding a porous structure to the interlayer. In one embodiment, an interlayer of L-605 is first applied to a substrate of Co--Cr--Mo by diffusion bonding at approximately 2200.degree. F. and then a fiber metal pad of CP-titanium is diffusion bonded to the interlayer at approximately 1650.degree. F. A layer of CP-titanium may optionally be placed intermediate the fiber metal pad and interlayer before the second diffusion step. In an alternative embodiment, MP-35N alloy may be substituted for the L-605 alloy.

The present invention relates generally to orthopaedic implant devices of the type having a porous surface into which bone tissue can grow or surgical cement can enter and, more particularly, to a method of bonding a porous surface structure of titanium or a titanium alloy onto a substrate of a cobalt-based alloy, whereby enhanced bonding strength and corrosion resistance is achieved.
Orthopaedic implant devices commonly include a porous surface to enhance attachment of the device to adjacent bone tissue. Consequently, various methods have developed for manufacturing an implant device having a porous surface. One such method involves securing a porous fiber metal structure, i.e., a wire mesh pad, to a portion of the surface of the device where bone ingrowth or attachment is desired. While the fiber metal pad generally provides a suitable porous surface, efforts to develop improved methods of attaching the pad to the implant surface continue. For instance, it is a desired to further improve the bonding strength and corrosion resistance of the attachment interface.
In several orthopaedic implant applications, it is desired to combine dissimilar metals in order to take advantage of the particular strength, biocompatibility, and corrosion resistance properties of the respective metals. For instance, as disclosed in UK Patent GB 2142544 B to Medcraft, it is known to combine a cobalt-based alloy with titanium or a titanium alloy, wherein one constitutes the substrate of an implant device and the other constitutes a wire mesh that is diffusion bonded to the substrate to provide a porous surface. However, diffusion bonding of commercially pure titanium porous structure (such as a porous pad) onto cobalt-based alloys requires elevated temperatures which reduces corrosion resistance of the composite structure. Furthermore, diffusion bonding of titanium porous structure directly onto a cobalt-based alloy does not produce necessary bond strength in the structure.
In another application involving a cobalt-based alloy and titanium, the femoral component of a knee prosthesis is fabricated by casting a cobalt-based alloy substrate and then securing a titanium fiber metal pad to the surface of the substrate by first plasma spraying a titanium coating on the surface. This bonding method is disclosed in U.S. Pat. No. 4,969,907 to Koch et al.
Both of the aforementioned bonding arrangements result in the formation of an alloy at the interface between components that tends to exhibit some corrosion at the interfacing layers. Nevertheless, it desired to provide an improved method of bonding a titanium porous surface to the surface of a cobalt-based alloy substrate, wherein bonding strength and corrosion resistance are enhanced.

Method of bonding titanium to a cobalt-based alloy substrate in an orthophedic implant device