Showing papers by "Mitsubishi Electric published in 1988"

Digital signal processor

Abstract: The present invention improves a digital signal processor, more particularly, calculation methods for motion compensation in reduceing a required amount of calculations when an amount of distortion between a last frame block and a current frame block; in processing a direct memory access at a higher efficiency; in processing a subdivided data calculation at a higher speed; in processing a branch instruction occurring in the pipeline process at a higher efficiency; and in processing an interruption occurring in a repeat process operation at greater convenience, and furthermore in reducing a required amount of calculations through minimum distortion searching processes hierarchized.

Practical reactive power allocation/operation planning using successive linear programming

Abstract: A method for reactive power planning is presented that it finds an optimal solution for both allocation and operation planning in large systems using linear programming (LP). The method utilizes calculated linear sensitivities including active power and voltage phase angle in the formulation. Although the overall method includes these relations, the number of constraints and variables are not augmented in its first procedure, APPROACH-1. Its second procedure, APPROACH-2, overcomes numerical problems caused by a dense constraint matrix. This is achieved by retaining untouched sparse sensitivities in the constraint matrix and by eliminating any calculations related to the inverse matrix. The results of applying this method to a practical 224-bus system and the IEEE-30 bus system verify its robustness and fast convergence. >

Change of Pt Distribution in the Active Components of Phosphoric Acid Fuel Cell

Abstract: Analyses post-mortem de l'evolution de la distribution du catalyseur platine dans les composants de la pile a combustible a l'acide phosphorique

Trapping of carriers in single quantum wells with different configurations of the confinement layers.

Abstract: This paper reports detailed experimental studies of low-temperature carrier trapping in GaAs/${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As single quantum wells with 5 nm and 1.2 nm thickness, respectively, with different confinement structures. Trapping efficiency and trapping dynamics are studied by means of photoluminescence, photoluminescence excitation spectroscopy, and picosecond luminescence spectroscopy. We obtain trapping efficiencies of about 40% for both the single quantum wells without additional confinement and separate-confinement-heterostructure quantum wells. The percentage of trapped carriers increases to about 60% to 80% for quantum wells cladded by graded-index separate-confinement heterostructures with parabolic band-gap profile. The maximum trapping efficiency of about 100% has been observed for a separate-confinement heterostructure with a linear band-gap profile. Interlayer well width fluctuations are found to be unimportant for the trapping behavior in our samples. Trapping times are appreciably shorter than the rise times of the quantum well photoluminescence, which are between 60 and 100 ps for the different structures. Surface recombination in the 0.2-\ensuremath{\mu}m-thick ${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As cladding layer does not reduce the trapping efficiency of the single quantum well without additional confinement compared with the separate-confinement heterostructure. An effective trapping area with about 80 nm width can be deduced on the basis of these results for the quantum-well structures with ungraded cladding layers.

Collision Avoidance Control among Moving Obstacles for a Mobile Robot on the Fuzzy Reasoning

Abstract: 本論文ではファジィ推論およびプロダクションルールを適用した移動ロボットの障害物回避方式を提案する.本方式の第1ステップでは, ファジィ推論によりロボットと障害物との間の静的および動的危険度を認識する.第2ステップでは, この危険度を用いてディシジョンテーブルで回避方向を決定する.この方式を用いると動的障害物に対するヒューリスティック回避を実現できる.ここでは, 本方式の有効性を検証したシミュレーション結果について報告する.

Polymorphic type inference in Prolog by abstract interpretation

Abstract: We present an abstract interpretation method for polymorphic type inference for Prolog programs. The method is an extension of our monomorphic type inference method, which is one of the examples of analyzing patterns of Prolog goals at calling time and exiting time by abstract interpretation. The framework is based on OLDT resolution by Tamaki and Sato, a hybrid of the top-down and bottom-up interpretations of Prolog programs. By abstracting the hybrid interpretation directly, we can compute approximately not only the type information at calling time and exiting time without infinite looping but also just the necessary and relevant information without waste. The monomorphic type inference method is extended to polymorphic types by introducting parameterized type definitions and generalizing operations for manipulating type information accordingly.

Disc file apparatus

Abstract: A disc file apparatus which holds a cartridge (1) at both surfaces thereof through a slit formed from an open end to a closed end of a bill-like-shaped cartridge holder (28), clamps by clampers (53) the cartridge (1) at both lateral sides thereof, and renders the axis of rotation of a pick-up and discharge mechanism (4) shifted from the center of gravity thereof so as to regulate rotation of the cartridge holder (28) by a stopper (78) in a range of an angle of 180° , whereby when the cartridge (1) is turned over or even when the same is subjected to an impact from the exterior, the cartridge is reliably held so that there is no fear that the rotational position thereof is shifted. The disc file apparatus uses linear ball bearing at each movable part and makes stand-by the utmost end of the clamper as close as possible to a stocker (2) or a recording and reproducing system (3), thereby improving the processing speed as a whole, and furthermore temporarily makes stand-by the cartridge (1) discharged from the recording and reproducing system just above an insertion and discharge port thereof by a transfer mechanism, thereby enabling a processing time to be reduced when a plurality of cartridges are continuously fed to the recording and reproducing system.

Advanced missile guidance system against very high speed target

Abstract: The advanced missile guidance system of surface-te air missile against very high speed target is studied. The system is characterized by intercepting very high speed targets with relatively low speed missiles. With this system, fairly small missiles are available for the mission and enough navigation time is assured. First, the successful lockon conditions are investigated, in regard to the interception geometries for various target speeds and altitudes. The results show that, in order to achieve small miss distance against the faster target than the interceptor, the aspect angle at lockon should be near 180°. Next, the optimal missile midcourse guidance law, which attains the optimal target aspect angle at lockon, is studied. The advanced guidance system proposed here is the combination of this optimal midcourse guidance and conventional proportional navigation homing guidance. The simulation results show that successful counterattack regions obtained by this system are far wider than the ones obtained by the less sophisticated guidance law.

Condensation of Ethylene Glycol on Horizontal Integral-Fin Tubes

Abstract: The problem of heat transfer during condensation on horizontal finned tbes is extremely complex. The difficulty arises from the essentially three-dimensiona character of the condensate flow, together with significant surface tension effects. The fact that the heat transfer enhancement can significantly exceed the surface area augmentation may be attrubutable in part to the small effective plate heights associated with the fin flanks and also to the effects of surface tension in locally thinning the condensate film. Progress has been made toward the theoretical understanding of the heat transfer in locally thinning the condensate film. Progress has been made toward the theoretical understanding of the heat transfer problem and for the related phenomenon of static liquid retention on horizontal finne tubes. Experimentally, the problem is made difficult by the requirement for high accuracy in measuring the relatively high vapor-side heat transfer coefficient and the need to avoid errors that can result from the presence of noncondensing gas or from the occurrence of dropwise condensation. The large number of variables involved also presents significant difficulty. The present note reports the continuation of a systematic experimental study. New data for ethylene glycol are given here.

A new mode of improved confinement in discharges with stationary density in JFT-2M

Abstract: A new mode of improved energy confinement, for which the confinement time is not worse or is sometimes even better than that for the well known H-mode and the density of which is in a quasi-stationary state, has been obtained in neutral beam heating experiments on JFT-2M. The new mode is different from the H-mode in many respects. The central electron temperature is higher in the new mode than in the H-mode. Radiation loss and density are reduced in the peripheral region but not in the central region. Therefore, the density and radiation profiles are highly peaked in the new mode, in contrast to the broad profiles in the H-mode. Particle confinement in the peripheral region seems to be worse in the new mode than in the H-mode. The new mode can be obtained in both divertor configurations and limiter discharges in JFT-2M.

Superconductivity of Screen-Printed YBa2Cu3OyThick Films on Y2BaCuO5Substrates

Abstract: YBa2Cu3Oy superconducting thick films have been prepared on Y2BaCuO5 substrate by the screen printing and sintering method. The critical temperature Tc and current density Jc at 77 K in an absence of magnetic fields were extremely high as compared with the films printed on the other ceramic substrates such as MgO, SrTiO3 and YSZ, and were 86 K and 3000 A/cm2, respectively.

Operating mechanism for a circuit breaker

Abstract: The present invention relates to an operating mechanism for a circuit breaker; having an opening means (3) carrying out open-circuit operation by deenergization thereof and a clos­ing means (7) carrying out closing-circuit operation by rotation of a cam (11) caused by deenergization of the closing means so that the opening means conserves energy by deenergization of the closing means and the closing means conserves energy by rotation of the cam; and the operating mechanism according to the present invention is provided with a large gear (8) fixed coaxially with the cam and lacking in teeth in part (8a) and a small gear (9) rotatably driven by a drive source in relation of engaging with the large gear, so that the non-tooth portion of the large gear is provided at the position thereof where the large gear disengages from the small gear just after the closing means completes its energy conservation, whereby the small gear, after completion of energy conservation of the closing means is completed, runs idle in the non-tooth por­tion and the drive source for the small gear is free from pulsation of a load and the drive source smoothly rotates, resulting in that a small drive source is enough for use and the large gear and small gear are not subjected to an over­load, thereby the present invention can provide an operating mechanism of a large current and a large capacity.

Clutter Effect on the Miss Distance of a Radar Homing Missile

Abstract: When the target Doppler frequency in a radar homing missile crosses the main lobe clutter spectrum at the terminal phase of its flight, a large miss distance is induced. This paper presents the quantitative analysis on this clutter effect using a program named SAMS (Statistical Assessment of Missile Systems), which is a hierarchical and generalized version of the SLAM (Statistical Linearization Adjoint Method). A homing missile is represented by triple time constants, a limiter, a second-order missile airframe, and proportional navigation. The main lobe clutter is imposed on to this system along with the target random maneuver, glint, fading, and receiver noise. By processing the covariance propagation of the system equation and the adjoint system, the miss distance and the contribution of each noise are calculated. The results reveal that the clutter effect is maximized if the target Doppler frequency begins to cross the main lobe clutter spectrum 2 s prior to the terminal time, and it is largely enhanced if the target random maneuver is combined. These effects are reduced, however, if the missile lateral acceleration capability is increased or the target lateral acceleration decreased. The radome effect is also analyzed by adding the related feedforward loop to the original system, which makes a considerable change in the miss distance.

Gate turn-off thyristor and manufacturing method thereof

Abstract: A gate turn-off thyristor has a damage layer (29), which provides recombination centers for trapping carriers, in an n-­type base layer (21). Carriers remaining in the n-type base layer (21) are quickly swept out at the time of turn-off operation by virtue of the damage layer (29), so that the turn-­off time of the thyristor can be reduced.

Closed loop control of the EGR rate using the oxygen sensor

Abstract: An effective method for reducing NOx emissions from automotive engines is the recirculation of the exhaust gas (EGR) to dilute the induced fresh air charge EGR systems are currently applied mostly with open-loop control A new closed-loop control system for EGR rate has been developed The most important point of this system is use of the feedback signal based on oxygen density at the intake charge for the engine

High speed and high accuracy XY-stage for electronic assembly

Abstract: A high-speed, high-accuracy, direct-drive XY-stage developed XY to meet the requirements for LSI or print-circuit board assembly is discussed. This stage has a moving-coil-type linear motor using an NdFeB magnet, which is about 1.5 times as strong as SmCo/sub 5/ rare-earth magnets. Computer aided engineering, including finite-element analysis, was applied to realize optimum design. A two-mode control method, consisting of a traveling mode and a positioning mode, has been developed to obtain stability and high speed positioning. Travel is 50 mm*50 mm, and maximum acceleration is 50 m/s/sup 2/, which is five times as fast as conventional XY-stages. >

High Density Schottky-Barrier Infrared Image Sensor

Abstract: In recent years silicide Schottky-barrier focal plane technology has received great interest because it is the most promising technology for high density infrared image sensors. However, improvement in not only the detector performance but also the readout architecture is indispensable for realizing high density infrared image sensors. This paper presents the advances in silicide Schottky-barrier focal plane technology and the design considerations for high resolution infrared image sensors with video quality. A 512x512-element platinum silicide Schottky-barrier infrared image sensor with a novel readout architecture is also described.

Fiber Orientation Control by Means of Magnetic Moment

Abstract: An attempt was analytically made to explore the feasibility of fiber orientation control in a short fiber composite by loading magnetic moment. The analysis was carried out for a paramagnetic short fiber coated with ferromagnetic substance. Formulations to predict the torque applied to the coated fiber and time required for the rotation of the fiber were presented. Numerical calculations based on the formulations showed that the fiber orienta tion control can be made by the loading of the magnetic moment even if the magnetic coating is thin and the magnetic field is reasonably low.

High-power and fundamental-mode oscillating flared sba lasers

Abstract: Flared SBA lasers with a flared waveguide are investigated. A single-lobed far-field pattern (FFP) parallel to the junction in CW oscillation at 25°C is maintained up to 80 mW.

Methods for transmitting and displaying a still picture image in a still picture video telephone apparatus

Abstract: A still picture video telephone apparatus adapted to transmit and receive, through a telephone line, still picture information put in from a television camera (14) or the like, during a telephone call, comprising a picture memory (20) for storing a plurality of pages of picture information consisting of a camera-taken picture memory portion which rewrites still picture information input therein delivered from the television camera at intervals of a predetermined period, a self-prepared picture memory portion which stores desired still picture information until arrival of a rewrite instruction, and an incoming picture memory portion which sequentially rewrites still picture information therein upon receipt of still picture information when its storage regions are filled up, an input means of memory region information for setting up regions for the self-prepared picture memory portion and the incoming picture memory portion within the picture memory, and picture memory control circuit (21) for controlling still picture information input to and output from the picture memory based on the memory region information, wherein the picture memory is capable of storing a plurality pages of still picture information and allocating memory regions to the self-provided picture memory portion and the incoming picture memory portion in various ways. Further, the present invention is a method for transmitting still picture image capable of extracting, according to the need, only a desired portion of the picture data stored in the picture memory thereby achieving highly efficient time-saving transmission. Furthermore, the present invention is a method for transmitting still picture image whereby clear picture image is displayed even when picture data of a different resolution is received and an accurate display is achieved even when picture data of a different aspect ratio is received at the signal receiver side.