We adopt a kind of Sarsa approach in order to compose an autonomous distributed AGV system. In our approach, updating any of the state values causes updating its relevant state values as well, so that the learning cost can be reduced. We also propose a multiple use of experience to reduce cost of reinforcement learning based on prior knowledge. Computer simulation is conducted and the feasibility of the proposed AGV management approach is discussed.

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Now in Japan we are coming to the advanced aging society and many problems attendant upon it. For example, home helps are getting on themselves and physically declining. They have several difficulties with taking care of seniors. As one of a scientific measure for this problem, an assisting robot is being developed and studied. In this study, we aim at power assist system which reduces user's efforts by wearing the robot on their body. We adopt assist ratio in cooperation works of human and robot as a way to regard the power rate of them. We propose a simple way to operate the robot such as controlling torque under a human supervision, therefore this enables us to enhance cooperation of power assist system between human and robot.

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Micromachines are expected to be used for non-destructive inspection of industrial pipe or a human body. In order to develop microactuators driven by static magnetic field, dynamic characteristics of a small magnet and magnetic fluid driven by the static magnetic field were measured and the results were compared with FEM electro-magnetic analysis.

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Essential understanding of flame structure in a microscopic combustion, regarding it understands a difference of a flame form to produce by getting activation energy to be necessary for combustion reaction by the combustion propagation or heat conversion. In particular we clarify a difference of the trace concentration of an oxidizer in the combustion ground that the local air ratio in the flame inside changes into, and there is possibility of combustion control by a molecule level in it. We developed the flexible double microframe that could each set a double pipe freely in order to make clear fuel and a combustion characteristic of an oxidizer microscopic mixed region, and a flame was local inside, and fuel and/oxygen began to make a mixture process of the air ratio changed into, light, regarding it with this study and examined the combustion characteristic.

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Gas flows in unsteady jets were calculated from a large eddy simulation (LES), and the effect of the initial injection-rate on flows and mixing process were investigated. Obtained results show that in the case that the injection speed rises slowly, the intensity of initial vortex-ring is low and the growth of turbulence is suppressed. As the result, turbulence mixing is also suppressed and local high-density spots are observed even in the downstream.

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The flame stability limits essentially define the fundamental operation of the combustion system. The critical conditions at the stability limits are highly dependent on flow configurations and some species of fuels. For various species of fuels (Methane, Propane and Hydrogen), the flame-base stability mechanism for flame holding has been studied. In this study, the transition behavior from the stable flame attached to nozzle rim to lifting and blow off is observed experimentally in unconfined, quiescent atmosphere air. The lifting and blow-off criteria are proposed for the diffusion flame. Experiments were conducted to investigate the flame structure for various nozzle diameters from 0.14 to 8.1 mm. The results obtained are as follows. It turns out that the minimum limit of a stable flame is not dependent on average jet speed, but it is dependent on fuel flow rate. Regarding to the micro scale nozzle, the flame length of the laminar flow is decided by fuel flow rate.

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The flame holding at the burner is one of the essential parts for combustion. Flame holding and lifting/blow-off at the burner rim and the stabilization mechanism have been studied. The nozzle diameter (curvature) at the upstream end of the diffusion flame adjacent to the burner rim plays important roles for the flame holding. The inverse diffusion flame (IDF) is the flame where the fuel and air streams of a normal diffusion flame (NDF) are reversed. The objectives are to make clear the mechanism of flame holding and stability limits. It is indicated to investigate further the combustion characteristics, stability and behaviors of the inverse diffusion flame (IDF).

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Numerical calculation of a non-premixed jet flame was performed using the Large Eddy Simulation (LES) with a flame sheet method. The results were compared with the experimental data measured by Laser Doppler Velocimetry and a thermo couple. Furthermore, production rate of turbulence energy was calculated based on the statistic data. The maximum point of density weighted average of Reynolds stress is located at fuel stream side of shear layer upstream. As a result, the production of the turbulence is mainly occurred in the fuel stream.

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The methyl alcohol liquid was sprayed from two-fluid type nozzle, and the spray combustion was performed. The droplets in that flames were measured by using a Phase Doppler Particle Analyzer. Time series distributions of droplets were obtained, and the group combustion number for each droplet cluster was estimated. The combustion behavior of droplets in the spray flame was discussed.

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Hydrophilic monomers are graft-polymerized to the surface of cloth after the plasma application. The characteristics of cloth changes to breathe moisture and to increase the adsorption of offensive odor simultaneously. In the present study, odor control properties of filter treated with nonthermal plasma were examined. One of the typical odor components, NH_3,was used. Nonthermal plasma was found to help recover deodorizing performance by decomposing bad odor components remaining on surface of the filter. The filter with graft-polymerized and plasma application was very durable. And in particle removal the filter treated both sides showed the best adsorption efficiency.

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Emulsified fuel spray combustion is supposed to be effective for the reduction of thermal NO_x discharge and particulate matter. In this study, we used emulsified fuels which contain water at the rate of 0-20% for a single cylinder 4 cycle diesel engine, and made a comparison about the influence of the water content of the emulsified fuel on exhaust emissions and fuel consumption rate. Consequently, although thermal NO_x was reduced by the decrease of the combustion temperature, concentration of CO and HC in the exhaust gas increased. The more the rate of water increased, the less the amount of particulate matter reduced. The consumption rate of the fuel had a minimum at the water content of 10-15%.

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Simultaneous removal of NOx, SOx and particulates using nonthermal plasma-chemical hybrid reactor has been studied. The nonthermal plasma is used to oxidize NO to NO_2. NO_2 is reduced to N_2 and Na_2SO_4 by using Na_2SO_3 solution and SO_2 combined with H_2O is reduced to Na_2SO_4 by NaOH solution. Diesel particulates are charged by the pulse corona and collected on the inner wall of the reactor. The nonthermal plasma-chemical hybrid-reactor removed 74% of NO_x, 100% of SO_2 and 88% of particulates in diesel emisson with the specific energy of 43.5 J/L.

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Experiments have been carried out to elucidate the flame stabilization and development on waste fuel combustion in high temperature and low oxygen by concentration using the electric furnace equipped in cylindrical closed bomb. The ambient temperature and oxygen concentration are set up at 400 to 800℃ and 5 to 21% by volume, respectively. Especially, the temperature distribution near the surface of solid waste fuels is measured to conform experimental data including the flame stabilization region. The acquisitions obtained in the study are as follows : (1) the influence of oxygen concentration and ambient temperature on combustion characteristics such as ignition delay, flaming duration and surface combustion period are revealed by temperature measurement in details and (2) the region of flame stabilization on waste fuel combustion has an inverse relationship between ambient temperature and oxygen concentration.

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The formation process of the slender liquid lump, which is produced in the laminar-turbulent transition process of a radial liquid sheet flow, is clarified. The radial liquid sheet is formed by the release of a radial liquid-film flowing on a disk from the edge of the disk to still air. When the Reynolds number is large, a concentric disturbance wave ('D wave') appeares and grows downstream on free surfaces of the liquid sheet. 'D wave' is caused by the unstable disturbance, which is attributable to the inflectional velocity distribution of the liquid sheet. After the growth of 'D wave', laminar-turbulent transition occurs and slender liquid lumps are formed. Slender liquid lumps disintegrate into drops downstream. The detail observation of the laminar-turbulent transition process reveals that the formation of the slender liquid lumps takes root in three-dimensional deformation of 'D wave'.

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Numerical study of turbulent flow in a open channel with side wall has been investigated by using direct numerical simulation. In the computation, staggered grid system is employed and consistent scheme is applied to the non-linear term. Time-averaged results are compared with the spectral data. It was found that the present computations could predict well the characteristic future of open channel flow. The location of maximum streamwise velocity more to the center direction of channel, that is different from those of open channel flow without side wall. The Reynolds number based on wall friction velocity and channel height is set to be 600. The slip wall condition is applied to the free surface. The budged of pressure-strain conditions are shown and the influence of side walls is discussed.

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Basic experiments on the turblent mixing of horizontally-injected high-density solution in vertically-upward water flow have been performed. Also, numerical calculations have been performed for experimental results by the finite volume method. The boudaries between complete and incomplete mixing have been clarified from the exeperiments. In complete mixing, the injected high-density solution is entrained completely into the vertically-upward water flow, while in incomplete mixing, the solution once falls fairly down in the upward water flow and thereafter is entrained into the water flow. The numerical calculations predict experimental results qualitatively; however, it is necessary to improve the numerical calculations particularly in order to predict the boudary water flow rate.

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In ANSYS, multi-field coupled analysis can be performed comparatively easily, by combining the "thermal flow analysis" and "other analysis". In the coupled analysis mainly concemed with CFD, it cannot but depend on the "sequential load vector coupled method" now. By the 1rst report, "the sequential load vector coupled method" was used and the approach of multi-field coupled analysis containing electrical parts and electronic circuits in thermal flow was explained using five simple examples of 2D. in this paper, extending to 3D practical large-scale models, the method of shortening calculation time is stated.

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Burners are often used in ore fusing furnace and the propagation of the thermal energy is dominantly heat radiation. Since the initial ore temperature is low, it will be molten by radiation thermal energies. However, ore will not melt enough and affect product quality. The improvement of product quality can be desired if such a phenomenon in a furnace can be grasped in numerical analysis. Here general-purpose FEM analysis code ANSYS/FLOTRAN is used. Authors devised the analysis by separating radiation analysis and thermal fluid analysis and defining radiation boundary conditions using array variables.

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JPARC project where neutrons are generated by spallation reaction in the target system. Large heat generates in the target by the reaction. Therefore various thermal hydraulic designs are needed to release the heat from the target. In a target, in order to avoid boil of cooling water, it designs so that surface-of-a-wall temperature may turn into below saturation temperature. However, if flow rate decreases by the pump trip, saturation temperature will be exceeded and boil will take place. At this time, since there was a possibility that the flow of cooling water may become unstable, the standard over the safety of a target was acquired by the forced convective boiling heat transfer experiment.

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In the combustion phenomenon, it is very difficult to know the state in furnace because the cost is too high and can't set an apparatus. But in the combustion phenomenon, it is important to know the state in furnace to reveal the process of the reactions and the combustion conditions. In this study, the state in furnace is simulated with k-ε model and eddy break up model and more. The state in furnace and the movement of fuel were analyzed.

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Recently, helicopters are watched as commuter aircraft. But noise of helicopters isn't desirable when they fly over cities. Blade-Vortex-Interaction noise (B. V. I. noise) occurs frequently before landing, and louder than other noises. The cause of B. V. I. noise is B. V. I. that is an impulsive fluctuation of pressure caused by an interaction between a blade of helicopter rotor and tip vortex. It is necessary to establish analyzing method of B. V. I. to design a low-noise-helicopter. In this research, we calculate the noise pressure by FHW equation on the base of flow obtained by discrete vortex method.

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Finite difference model is proposed to predict acoustics induced by turbulence in the wake of a body located in free stream. Flowfield generated around the body is calculated by applying such a conventional procedure for incompressible fluid as MAC schem. Hyperbolic differential equations which are equivalent to Lighthill wave equation of acoustic analogy are calculated to simulate aeroacoustic field generated from flow in the wake.

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When an acoustic excitation is applied to a transmission line system, such as series line and branching line systems, the system is resonated at its own resonance frequencies. In that case the resonance frequencies are not integral multiple of fundamental frequency as single line system. Resonance frequencies are determined by the system parameters and properties of air. Using this property, the line length may be obtained by observing resonance frequencies. Then in the paper, for a few systems which have the input at starting point and the outputs at arbitrary points, we find the characteristic equation, and consider measurement method of the line length from resonance frequencies.

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Beam-like jet flow occurs from a sound source in the propagation direction of sound. This flow is called "acoustic streaming". In this study, the authors numerically analyze circulating axisymmetric acoustic streaming in a closed cylindrical tank. The flow is driven by an axisymmetric-shaped actuator oscillating on the center of the tank base, which transmits an intense ultrasound into fluid. The purpose is to get the optimal design of oscillator geometry for acoustic streaming. Namely, in order to investigate the influence of the flows that various shapes of oscillators generate, the authors numerically analyze the flows include by the spherical-type oscillators with different curvatures as well as the circular-plate-type one.

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This paper discribes about theoritical analyses of cavitation in centrifugal pump. A linear stability analysis is carried out by using the singularity method based on a closed cavity model allowing the cavity length freely to change. For 4 bladed impeller, a mode corresponding to the transition to alternate blade cavitation was examined. For 5 bladed impeller, various kind of rotating cavitation was found.

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Analysis of cavitation in a Plano-Convex blade cascade was carried out by a singularity method. As a result, it was found that the cavity volume is smaller than the case of flat plate cascade, and shockless angle of attack is an import parameter. A stability analysis shows that the unstable region of several modes are smaller for Plano-Convex blade.

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The purpose of this study is to reduce cavitation noise generated behind a butterfly-valve set in a straight pipe. The main reason of cavitation occurrence is an abrupt decrease of the pressure behind the valve. In our experiments, the duct was partly enlarged to recover the pressure behind the valve and to reduce cavitation occurrence. It was confirmed that this method is effective to reduce cavitation through the experiments using a pipe with a circular cross section. Moreover, we carried out the experiments using butterfly-valve with aileron. And we confirmed that the effect of the aileron on the noise was not so large.

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This paper deals with an experimental study on the suppression method of cavitation in a cylindrical choke for the steady and unsteady flows. The unsteady flow takes a trapezoid form with time at the upstream of a choke. Experiments were carried out for the combination of the nozzle placed in the upstream and the baffle plate placed in the downstream in the choke. The pressures of four locations in these tests were measured with a pressure transducer at the same time for various unsteady flows. Moreover, cavitation pictures was taken and the cavitation noise was measured. As a result, the combination of the nozzle and the baffle plate was a good method for the suppression of cavitation.

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This paper deals with an experimental study on the pressure distribution and the behavior of cavitation bubbles for steady and unsteady flows. The unsteady flow took a trapezoid form with time at the upstream in a choke. The static pressures in a choke center were measured with the Pitot tube which placed in the center of a baffle plate. The surface pressures of four locations in a choke were measured with a pressure transducer for various unsteady flows. The behavior of cavitation bubbles was observed by a high-speed camera (100,000∿200,000 frames/s). It was found that when the cavitation developed sufficiently in a choke, there was no pressure difference between the center and the wall surface in a choke, and behavior at the moment of the collapsing bubble in a choke was captured by the high-speed camera.

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Casting of fiber inserted aluminum alloy composite strip was tried using a downward melt drag twin roll caster. In this method, casting of the strip and insertion of the fiber were operated simultaneously. The steel wire with diameter of 0.3mm was inserted into the strip. When roll speed was slow, and pouring temperature was high, the fiber could be inserted into the strip without gap between the fiber and the strip. The fiber inserted composite strip could be cold rolled. The reduction of the fiber and the strip was almost equal. The gap between the fiber and the strip could be improved by the rolling. Reaction between the fiber and the strip was investigated using EPMA.

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Two types of twin roll caster for casting of wire inserted composite strip were devised. One is a method of using a downward melt drag twin roll caster. It was possible to cast wire inserted into the strip, by inserting wire in the puddle formed on the lower roll. Another is a method which was combined the downward melt drag twin roll caster and the melt drag twin roll caster. This method could cast wire inserted clad strip by pouting different alloy for each nozzle. If the same alloy was poured, the thicker strip could be cast. Moreover, the ticker wire could be inserted.

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Organic-inorganic nano hybrid material was fabricated by dispersing the very fine inorganic particle in nano order into the polymer. With this technology, the high performance materials could be respected. Here, the soft composite with good flexibility was developed based on polyurethane/silica nano hybrid. The tensile test, flexible test, and heat resistance test were conducted. As the result, the developed soft composite had the good performance on heat resisting property and flexibility. It is respected that the developed materials will have wide use in many fields.

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In this paper, the characteristics of supersonic wave in unidirectional CFRP composites were investigated. The ultrasonic velocity and attenuation coefficient of the unidirectional composites were measured under loading. Then based on the acousttoelasticity effect, the anisotropic behavior of the materials could be made clear. It was shown there were good relationships between stresses and wave velocity, stress and attenuation coefficient. This shows that the possibility of the acoustoelasticity effect to be applied in the composites fields.

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A commercial AZ31 cast magnesium alloy was tested in compression in the temperature range from 296 K to 723 K and at strain rates of (10)^<-3>S^<-1>, (10)^<-2>S^<-1>, (10)^<-1>S^<-1> and (10)^<-3>S^<-1>. Based on the data obtained at the strain rate range from (10)^<-3>S^<-1> to 10^<-1>S^<-1>, the influence of the elevated temperature and the strain rates on the flow stress at a plastic strain of 0.1 was analyzed using the Zener-Hollomon parameter Z. The measured value of the strain rate sensitivity m varied from 0.11 at 523 K to 0.20 at 723 K. The measured value of the apparent activation energy was 144 kJ/mol.

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Semisolid strip casting of AC4C aluminum alloy for casting was tried using a melt drag twin roll caster equipped with a cooling slope. Semisolid slurry was made from melt only pouring the melt on the cooling slope. The melt drag twin roll caster was improved into a semisolid twin roll caster only equipping the cooling slope without modification. Casting speed of AC4C strip could be improved up to 90 m/min by the effect of the semisolid strip casting. The microstructure of the strip cast from semisolid slurry was different from that of the strip cast from the molten metal. Primary crystal of the semisolid cast strip was spherical. Eutectic Si was very fine and globular. Mechanical property of AC4C strip after homogenization, cold rolling and T6 heat treatment was as below, UTS : 270 MPa, 0.2%proof stress : 190 MPa and elongation : 18%. The elongation was especially improved by the semisolid strip casting.

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Two kinds of billetless thixoforming processes were devised in the present study. One process employed a cooling slope, and the other exploited low superheat casting. The size of ingot can be easily varied accordingly by appropriate choice of ladle and die. The cooling slope is a very simple, compact and cheap piece of equipment with low associated running costs. The primary crystals of test pieces generated in the course of this present study were spheroidal, and the general morphology of the ingot microstructures, when heated up to semisolid condition, was very similar to the microstructures obtained by conventional semisolid casting routes. The mechanical properties of test pieces produced from ingots cast in this present study were very similar to properties of products made by conventional thixoforming. Tensile strengths of 293 MPa and 15% elongation were obtained after T6 heat treatment.

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This work describes two recently invented simple rheocasting processes. One process used a cooling slope and the other low superheat casting in order to generate semisolid slurries with spheroidal microstructures that are amenable to thixoforming. In the former process, A356 aluminum alloy was poured into the lower part of a die and immediately an upper die, containing an internal cavity, was inserted in the lower die half. The A356 alloy was in a semisolid slurry form when it flowed into the lower die via a cooling slope. In the latter process, the A356 changed from fully liquid to semisolid slurry condition cooling in the lower die half after being poured into it as low superheat casting. The primary crystals of the cast metal in the both processes became spheroidal. There was no major observable difference between conventional thixocasting microstructures and those of the two processes used in the present study. The mechanical properties obtained in the present study were : Tensile strengths of 310 MPa and 18% elongation for the process using the cooling slope, and tensile strengths of 290 MPa and 12% elongation for the process using the low superheat casting.

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This paper describes an identification probrem of a sound source position. In this research, in order to identify the sound source position, the boundary element method and the extended Kalman filter are used. First, sound pressures of several observing points are measured. Next, when the position of the sound source is located in an assumed position, the sound pressures of observing points are calculated by the boundary element method, and the position of the sound source which is an unknown parameter is estimated with an extended Kalman filter. The validity of this technique was shown from the result of simulation.

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Hearing aids could help the hearing impaired to carry conversations and watching TV. However, once outdoors, hearing aids used commonly causes the discomfort to many. It is very common not to use hearing aids outdoors though it may increase the danger to miss alarm or siren. So, it is important to develop an aiding system which could notice the hearing impaired not only by hearing but other manners, such as vibration, lighting and so on. Then, the sudden alarm could be notified so that the safety of the hearing impaired could be improved. As the first step to develop these aiding systems, sirens for emergency vehicles, and alarms for railroad crossing were used for tests of discrimination and notice. The sounds of these alarms are analyzed by FFT and discriminated by band pass filter. However, wrong discrimination occurs when the noise exists inside of bands. The neural network was used to improve discrimination for various alarm sounds. The results of discrimination did not change because the classification of the sounds was by FFT. The learning by the neural network will be more effective to aiding system after alarm is characterized with time and frequencies.

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Presently, the road sign is located in the tunnel, and it takes up the big space. So, in order to cut down the cost of tunnel construction, reduction of the space for road sign installation is desired. For this purpose, we attempted a research to give information to driver by using the holographic technology. Holography is a technology which records and reconstructs distribution of the amplitude and phase of light wave by using interference and diffraction. The decent reconstruction image could be obtained as a result of the experiment.

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In this paper, we address the problem of predicting the trajectory of the moving target, in order to compensate the time delay. The goal is to achieve the high accuracy tracking control in visual servoing system. Since the dynamics of the target are assumed to be unknown, based on the available information on the target polynomial trend model or Autoregressive model is constructed to predict the future information on the target. The well-known least squares method is used to estimate the model parameters. On the decision of the order of model, we propose the method is used to estimate the model parameters. On the decision of the order of model, we propose the method for real-time selecting the optimal order by AIC. To demonstrate the effectiveness of the prediction, real-time experiments in the system consist of 3 DOF manipulator and fixed stereovision configuration are presented. As a result, it succeeded to about 50% in the decrease of tracking error in comparison with the case in which there was no prediction.

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This paper describes a new data processing technique used in the pulse heating thermographic NDT. The surface temperature after heating is measured by high-speed infrared camera. The shape of transient temperature descent curve, which reflects defect parameters such as depth and size, was analyzed by the Fourier series. It was found that the coefficient of the Fourier series, a_n, b_n, were effectively used to determine depth and size of the defects. This method was also applied successfully to the detection of impact delamination damage in the advanced CFRP plates.

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The thermal expansion coefficient of rectangular shaped specimens at low temperatures was measured by ESPI(Electronic Speckle Pattern Interferometry). The thermal expansion coefficient was obtained from the thermal strain acquired by ESPI and the temperature change. Polytetrafluoroethylene(PTFE) were investigated. The thermal expansion coefficients in the range of 50&acd;600(×10^<-6>K^<-1>) were obtained in the temperature from 100K to 350K.

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This paper presents the numerical test results for the examination of the measurement accuracy of speckle interferometry. In the measurement of in-plane displacement of object surface, the technique of optical flow, which is also called spatial temporal derivative method, is employed to increase the reliability of the detected results for the range of smaller displacement. The performance test resuls in numerical simulation show that the RMS error of the optical flow is larger than that of the direct cross-correlation method for the in-plane displacement <1.5 pixel. Furthermore the validity of the numerical approach to the out-of-plane displacement measurement with speckle interferometer is confirmed.

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The shock wave that arises from a collapse of the bubble generated by a pulse electric discharge in water was observed with real time holographic interferometry. The holographic interferograms of shock wave are recorded by using submicrosecond shutting apparatus and CCD camera. The double exposure records of a shock wave measured the shock speed at an interval of 3μs and is obtained with 1500&acd;2000m/s. In the case of 1500m/s shock speed, the interferogram is analyzed by Fourier transform method and is converted into the distribution of pressure value.

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