In this study, a control algorithm for the active rocking char is proposed. This algorithm adjusts the frequency of "comfortable swing" to the individual. The "comfortable swing" is the motion of active rocking chair evaluated with comfortable. It is the model motion simulating the swing of rocking chair with constant period and the amplitude is fluctuated in the relationship of 1/f fluctuation. The algorithm uses the average period of the heartbeat and the "comfort index" as the evaluation criterions. The "comfort index" is calculated from the heartbeat fluctuation and evaluates the comfortableness on the swing of active rocking chair. Then, the effectiveness of proposed algorithm is confirmed by the experiment. The "comfort index" is increased by changing the frequency of "comfortable swing" according to the instruction of proposed algorithm.

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When operator in process plant was exposed to noise, the working efficiency is greatly affected by not only noise level but also acoustic characteristics. This paper describes; (i) the result of analysis regarding noise and working efficiency in consideration of cognition engineering, (ii) the result of experiment regarding broadband noise and narrowband noise, (iii) the example of noise countermeasure for work area affected by narrowband noise from rotating machinery, to investigate and propose the optimum noise countermeasures and the evaluation methods for process plant considering acoustic characteristics.

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This paper describes the method of designing engine sound quality at the early stage of product development. Because engine sound characteristics is determined by its fundamental structural dynamics and combustion process, engine designers need to know how the engine will sound well in advance before their designs are implemented into hardware. For this purpose, conventional sound quality evaluation tools will not be any help because they modify recorded sounds. To solve this problem, the authors created sound waveforms of combustion sound by simulating their physical generating mechanisms in a computer. The waveforms were then used in psycho-acoustic experiments using multi-media functions of personal computers. To give user-friendly environment for engine designers, graphic user interface (GUI) was development. Another method developed in this study was to use wavelet analysis and reconstruction. Intermittently occurring sound as valve noise was efficiently distinguished even under heavy background noise environments.

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About possibilities of the radiation of the auditory signal for walking by the blind, this study describes a side that blind people generate continual regulation to approach targets and destinations by adjustments of their body toward the speaker emitted the auditory signal. In subway stations, KAIGAN-line in Kobe, we observed that two blind persons approached the ticket gate with the radiation of the auditory signals. Based on their oriented locomotion in the structure near the ticket gate, they explored the turning place to the ticket gate by adjusting their steps and turning their head toward the radiation of the auditory signal without reaching the junction of tactile tiles. These adjustments do not always need to discriminate the indication as a signal. The random radiation by setting the auditory signal is a potential target for continual regulation to approach in preference to learning the auditory indications.

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I had been transferred to Environmental Research and Training Center (ERTC) of Thailand from 1999 of March to 2001 of February, to transfer the environment noise technologies as JICA Expert. This paper reports on the present state of Noise Environment in Thailand I survey during this period. The contents of this paper consists of 1) The present state of Noise Environment in Thai, 2) The traffic system and Traffic noise condition, 3) Environmental Noise condition in Thai city, 4) Thai views on this traffic noise condition. The city noise in Thailand is almost the traffic noises, which are almost the internal engine exhaust noise of 1) Motorcycle, 2) Tuk Tuk (three wheels Thai-car), 3) Bus, Truck etc. of old model and 4) Long tail boat on the rive and canal. And the reasons that the traffic noise in big city, for example Bangkok is bigger are : 1) Economical condition, 2) Don't be used the adaptive exhaust silencer by technical misunderstand, 3) Thai citizen ls lack of interest for traffic noise, 4) Can't control traffic noise by law. Traffic noise problems occur not only in big cities of Thailand but also in big cities of Southeast Asia by same reasons. My conclusion is that the policy of Japanese economy and the policy of Japanese manufacturers as supplier of vehicles are deeply concerned in the traffic noise problems of Southeast Asia and we have to discuss and resolve traffic noise problems in Southeast Asia as our problems.

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Assessment of noise impact on surrounding residential area becomes one of mandatory requirements prior to construction of the facilities. Industrial and international standards provide a method of comprehensive assessment for huge plant. These standards, however, does not give the cost information of noise control. Some papers present methods of noise assessment including costs of noise control for petroleum and petrochemical plants, but not for LNG plant. This paper investigates the costs of noise control for LNG plant and proposes the method of comprehensive noise assessment including costs. It also contains the problems involved in the methods.

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This paper considers the minimization of the total acoustic power radiated from a large duct opening. The sound field in the large duct opening is not always represented by a harmonic modal function. Therefore, the authors consider that the complex pressure amplitude at any position in duct opening can be regarded as random function, and propose a method employing an active noise control in order to minimize the total acoustic power by designing the duct opening, leading to change the complex pressure amplitude in the duct opening. The power reducing performance was verified by applying the method to the transducer noise radiating from the large duct opening.

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The noise at the lower parts of railway cars consists of rolling noise, aerodynamic noise and mechanical and electrical noise. There are some papers about noise source separation at the lower parts of railway cars. For the purpose of identifying the noise from different sources at the lower parts of railway cars, we visualized the noise distribution which differs under various conditions. This paper describes a trial for noise source separation at the lower parts of railway cars by using the data measured by means of sound intensity microphones and an acoustic mirror with ellipsoidal shape which were set near the rails of a Shinkansen line and a conventional line.

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Wind induced noise on a microphone is indeed a problem for wind turbine noise measurements. To test windscreens fabricated to investigated possible improvement of its performance, three secondary windscreens were designed and produced based on various ideas as well as according to the IEC standard of 61400-11. Test results revealed that a microphone senses a pressure fluctuation due to the wind speed fluctuation and, thus, that larger windscreen gave better performance for wide range of frequencies.

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This paper describes a simulation on the effect of the surface impedance for reducing aerodynamic sound from a circular cylinder. First, derivation of the ideal surface impedance that eliminates the pressure fluctuation on the body surface, is discussed. Then the simulation is conducted with using the Large Eddy Simulation (LES) techniques under the subject of Computational Fluid Dynamics (CFD) at Reynolds number, 3000. The imaginary domain under the surface is introduced to realized the effect of the finite impedance. In the simulation only larger impedance than the ideal one is applied to the surface due to the computational instability which restrains the lower limit of impedance. Even for the larger impedance, effect, of setting-up the surface impedance is verified by the simulation with the fact that the amplitude of the surface pressure fluctuation decreases remarkably.

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A method to simulate the generation of tunnel compression wave at train entry is investigated by using a simple geometry model. The tunnel is represented by a circular cylinder and the train by an axisymmetric body which has a cross-sectional area distribution equivalent to that of the actual train. In order to simulate the entry into a double tracked tunnel, the train center axis is positioned offset from the tunnel axis and the effect of the ground plane is treated by the mirror image method. Analysis and model experiments are performed to confirm the validity of the present method to use a simple geometry model. The difference of the peak pressure gradient of the compression wave has turned out to be within a few percent between field measurements and model experiments.

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The mechanism of the coherent structure generated to the span direction in the wake, which passed across a flat plate blade, was analyzed with the 3-dimensional flow field by the solution of a finite volume method. According to visualization by the streamline and the normalized helicity, the longitudinal vorticity Ω_x was generated where the mainstream and the 3-dimensional share layer interfered at the tip of a blade. Moreover, a visualization that was made by the surface of the equivalent level of the Ω_x, was able to catch ten regularity cells in the 2-dinensional share layer, In this paper, it was shown mathematically that the Reynolds share stress formed standing wave as a solution of Poisson equation for the ρ<v'w'>^^^-, also we pointed out that the standing wave was closely connected for the sound sources to the span direction as a result of the prediction of the discrete frequency noise within ±3dB errors.

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An investigation of characteristics of fluid dynamics and noise for a centrifugal fan with inducer was conducted with respect to the effects of three parameters : inlet angle, outlet angle and 3 dimensional outlet angle. Moreover, we proposed a new method to calculate the width of wake, which is an important parameter to control the turbulent noise. It is shown that the inlet angle hardly effects on turbulent noise but the outlet angle effects on the turbulent noise. The optimum value of outlet angle is about 48 degree. The experimental values of the overall turbulent noise with L-weighting and A-weighting functions agreed well-predicted values.

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Discrete frequency noise of a cross flow fan is generated by periodic flow fluctuation according to the rotation of an impeller. The interference of an impeller and a stabilizer is known as the main noise source. In this work, the discrete frequency noise source and the characteristics of the sound propagation of a cross flow fan were visualized according to operation points. The time sequential propagation of the sound wave was reconstructed by using an acoustic holography method. From the visualization of the discrete frequency noise, the following results were obtained. When the flow rate coefficient is large, the dominant discrete frequency noise source was observed at the contiguous area of an impeller and a stabilizer. And it shifts to the contiguous area of an impeller and a casing wall according to the decrease of the flow rate coefficient.

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An experimental method to analyze the damping characteristics of hydraulic components is proposed in this report. By using our 3-mirophones Method, the absorption coefficient, propagation constants and the characteristic impedance of the conponent in the liquid-filled piping systems were measured. Experiments were conducted on the thin-tubes in the side branch pipe. Moreover, by using these damping characteristics of the conponent, we analyzed the pressure pulsation of the total hydraulic system. From the results obtained, this method is useful to evaluate the pulsation characteristics of the hydraulic systems

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Prediction method of acoustic noise is necessary in product design. In this paper, SEA (Statistical Energy Analysis) method is used to predict transmission path of acoustic noise and vibration for large-scale structures. Accuracy of SEA depends on SEA parameters (Damping Loss Factor, Coupling Loss Factor, and so on). In this study, authors obtained SEA parameters of a model for transmitted sound through a panel by using 3 elements PIM (Power Injection Method) and 2 elements APIM (Approximated Power Injection Method) experimentally. Then validity of the parameters is discussed by comparing the experimental values obtained in this study with theoretical values obtained by Mass Law.

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The object of present paper is a pick up and a suppression of specific vibration modes which occur such problems, it means here low frequency modes, among all of generated vibration modes in structure. Fist of all, a design of modal sensor made of PVDF film is proposed to pick up only low frequency modes separately by using FEM analysis. Then, an applied method of SMA actuator, which can generate great force in a field of low frequency, is explained. By using these PVDF modal sensor and SMA moment actuator, vibration model can be simplified by means of modification to low dimensions. Consequently, modal control system, which suppresses only low frequency vibration modes, is constructed. At the end of the present paper, effect of this control system is demonstrated experimentally.

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Despite its unique characteristics, having a large displacement and recovery force per unit volume even compared to traditional electro-hydraulic servo mechanical actuators or to famous small-sized and high-output exciting actuators, PZT, there are not so many studies on SMA 'actuator for vibration control. The main reasons are considered to be : (1) its difficulty of temperature control, (2) its slow response speed, and (3) its one-way transformation. The purpose of this paper is to realize SMA 'active' actuator solving the above-mentioned problems for vibration suppression. First of all, actuators using SMA wires, partly embedded in CFRP, were fabricated in consideration of SMA/matrix interfacial strength. Their thermo-mechanical behavior had been studied in combination with a filtered x-LMS control system including a cooling system. These lightweight actuators were mounted on beam structure which is to be put to vibration control. Recovery force of the beam structure itself was used as reactive force against that generated by SMA. As a result, actuator which is favorable for low frequency vibration modes suppression, i.e. having a large displacement and a large force, was obtained.

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This paper describes the active control systems for reducing floor impulse noise. The control system is comprised of actively controlled modular thin plates, which wholly cover the surface of concrete slab structure in the ceiling, and in each of which the mechanical vibration is controlled independently with bimorph type piezoelectric actuators. An active control system of modular plate is presented, where five actuators and five sensors are applied to control low frequency modes of bending vibration in the plate. The control system is now under development, main investigation items of which are designing of vibration characteristics of modular thin plate, the active control system appropriate to the characteristics and cost reduction of the actuators and sensors.

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Recently, active sound control system has been used to control undesirable noise. This system is good for controlling 1-dimentinal sound field. However, it is difficult to control 3-dimentional sound field where sound wave spreads in all directions. In this paper, we try to control 3-dimentional sound field caused by incoming noise and the arrangement of control sound sources and error microphones is investigated through simulations and experiments.

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This paper proposes an active noise controller with Filtered-X Fast Transversal Filter (FXFTF) algorithm in 3-Dimentional acoustic field which outside noise makes. Generally, in active noise control, Filtered-X LMS (FXLMS) algorithm is applied because of its simplicity and stability. However, FXLMS algorithm has a fault that the convergence speed is slow. On the other hand, some adaptive algorithms based on least squares method are known with faster convergence speed than LMS type algorithm although the calculated amount is large. If an algorithm based on least squares method is able to be applied to active noise control system, it is prospective that the field of active noise control is spread. From this point of view this paper picks up FXFTF algorithm based on least squares method. By means of Computer simulation and experimental analysis the performance of FXFTF algorithm is compared to that of FXLMS algorithm. With the result of the comparison it is shown that FXFTF algorithm has faster convergence speed than FXLMS algorithm.

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This paper describes the effectiveness of time domain analysis for improvement engine noise. When we analyze the source of engine noise or engine vibration, we apply stationary analysis with time averaging measurement conventionary. But this analysis is difficult to exactly analyze the phenomena which changes within a short period of time. So we apply the time domain analysis which is measured with Nonstationary sound holography & Laser doppler vibrometer which made the analysis within short time priods possible, and we confirmed this analysis is effective for improvement of engine noise.

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It has known that ballast for tracks has disposition of acoustic absorption, but absorption of granular material like ballast has not been estimated enough. This paper describes properties of acoustic absorption for granular structures. Selected measuring materials were bearing steal ball (φ3.0mm), plastic bullet (φ6.0mm), pachinko ball (φ11.0mm) and marble (φ15.7mm), in order to exclude heterogeneity of shape. The 2 microphone method was used to measure acoustic absorption coefficient. Influence of grain diameter, thickness of acoustic absorber and air layer were estimated. The result obtained that sound absorption coefficient is higher according as diameter of grains is smaller.

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This paper deals with the characteristic of noise reduction of perforated-plug muffler with self generated flow noise. The perforated-plug muffler is a kind of reactive silencer, attenuating noise by a pipe with a closed end and a perforated surface inserted into an expansion chamber. It is widely used in various fields but its design method considering the self generated flow noise has not been cleared. The experiments were carried out by using low noise wind tunnel. It was cleared that arrangement of the pipe with the perforated-plug, that is downstream or upstream to the expansion chamber, affected not only the pressure loss but also the flow noise.

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Piping systems for steam or gases with a pressure reducing device can cause acoustically induced vibration, resulting in material fatigue failure in process plant. Numerical investigation using sound-structure interaction analysis has been done to find the possible solution to reduce the dynamic stress level in the piping structure. The result shows that appropriate reinforcing of the pipe structure such as use of circumferential stiffener rings change the structural characteristic and reduce the maximum stress in the pipe wall. Stress generated by the thrust load is also evaluated. The effect of stress reduction by stiffener ring can be larger for acoustic excitation than that for thrust load. Structural natural frequency is applied to evaluate the effectiveness of reinforcement of piping structure.

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Hydrodynamic tones are radiated from water pumps in some operating condition and the cause of these tone are generated by the self-excited unsteady flow crossing the annular grooves of pump seals. Characteristics of these tone from the annular grooves of seals were experimentally studied by using the test stand for measuring the rotor-dynamics of seals and lubricate bearings with support of the active magnetic bearing. It was made clear that the groove size, the leak flow velocity, the length of seal changed tone frequencies and intensity. The results of study suggest that some acoustic resonance phenomena dominate the generation of the self-excited tone from seal flows. Not only size of groove seal but also the length of annular flow-pass might have some relations to the resonance.

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Heating value of gaseous fuel produced from solid fuel (wastes and biomass) gasification systems is as low 1/10 of that of natural gas, and there is almost no established energy conversion methods for such low-BTU gas. Two kinds of simulated low-BTU gas produced from natural gas diluted with nitrogen (methane rich) and obtained from two-step pyrolysis/reforming gasification (contain hydrogen and CO) were tested in a commercial-scale dual fueled diesel engine. In these experiments, power output was fixed at 37kW, 29kW, 22kW and 11kW respectively by controlling the gas oil supply, when low-BTU gas supply was changed. It was demonstrated that nearly 80% of oil supply can be replaced by low-BTU fuel gas with slight decrease of the thermal efficiency. It is possible to reduce NOx emission by low-BTU gas supply. Experimental results show that dual fueled diesel engines are quite feasible option for efficient utilization of low-BTU gas.

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After "the Action Program to Arrest Global Warming" was decides at Cabinet in 1990,utilization of residual heat energy from waste incinerators has been positively put into effect to reduce fossil fuel use. Above all the combined system of a steam turbine and a gas turbine has been drawn considerable attention, which was introduced to our city and keeping a good performances. The system features ; (1) Effective use of an emergency power generator for cost reduction, (2) DSS operation of the gas turbine, (3) Automatic combustion rate tuning system aimed to maximize the income of generated electricity. The next step is planned to sell the residual electricity as a "green purchase item" at auction.

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Energy for power generation is almost fossil fuel and atomic energy in Japan. The new energy that is natural energy such as solar energy, wind force, geothermal energy and hydrauric power and biomass should be considered as alternative energy to reduce CO_2 emission. Energy from waste is discussed as one of new energy. Ministry of Economy, Trade and Industry has set up the aim that the power generation from waste in 2010 becomes five times of 1999. One the other hand the new technology for waste treatment is adopted in recent years. The system can produce char that has high calorific value and similar characteristics to pulverized coal. This paper introduces the combined system of pyrolysis system and coal power generation plant. If the char produced in waste treatment plant is utilized in power plant as fuel, the power generation will become 1.7 times of the pyrolysis and melting plant of waste treatment.

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It is becoming a problem that sorts out recycling materials efficiently when the plastic contained in various garbage is recycled in refuse paper & plastic fuel, etc. It is very important to sort out the recyclable quality of the material and a non-recyclable substance in advance. For example, in case of "plastics other than a PET bottle" imposed by full enforcement of Law for Promotion of Selective Collection and Recycling of Containers and Packaging, it is necessary to remove a chlorine ingredient (PVC) and sort out paper material and plastic material making a calorie regularity. "Paper & Plastic Sorting System" became possible. It has some specifications. Sorting capability is high. Three kinds of sorting put in practical use. The plant this time Commercial operation has been performed for about one year or more.

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It is necessary to construct the information network system which constituted by consumer, producer and administration, etc. in order to plan the optimum recycling system. This study constructed the algorithm which deduced optimum recycling system based on dispersive product information from the viewpoint of energy and resources. This model was constructed by applying multiagent system. By the agent with the criterion respectively affecting the product-waste database, it becomes possible that the optimum recycling map is calculated.

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Recently, in order to consumer society shifts to Recycling-based Society, it is required for products' parts to be used long-term. Therefore we aim to prove the effectiveness for the protection of the environment and the resource by promoting reuse parts. In this study, from this point of view, we promote reuse parts in the case of recycling of End-of-Life Vehicle (ELV). In this report, we made tree diagrams of disassembly for estimating disassembling property. And with the car disassembling data, we estimate the Life Cycle Assessment of cars. As a result, we proposed the guidelines about car's Disassembly-Oriented Design, and showed that using reuse parts and recycling Automobile Shredder Residue (ASR) is effective for resolving problems about environment and waste.

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Recently it is required to shift consumer society to Recycling-based Society. Therefore we proposed a concept for the product upgrading by adopting the new environment-friendly technology without wasting its life. In this study we aim to prove the effectiveness for the protection of the environment and the resource with that concept. In this report, we upgraded the regenerative braking system of an electric vehicle that converted from an internal-combustion vehicle. As a result, the drive range by one time charge increased 20.6%, and it became 103.1km. And compared with the internal-combustion vehicle, our EV reduced 40% of CO_2 and 20% of NO_2.

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In these years, increase of wastes and exhaust of resource become major issues according to the progress of mass productive, mass consumptive and mass waste economic system. As the correspondence, the construction of the sustainable society is strongly required. For constructing such society, the consideration to 3R (Reduce, Reuse, Recycle) at the design stage of industrial products become very important. Especially, as concerns Reuse and Recycle, the improvement of disassembling property of the products is one of the most important things to be considered. In this study, we attempted to investigate Disassembly-Oriented Design (DOD) for welfare tools, of which demand is estimated to increase due to the arrival of the aging society, by disassembling them. The products that we disassembled were nursing care bed and wheelchair. By disassembling them we understood the problems of the structure and compared the disassembling property of these products by applying the method of estimating products' disassembling property. Then we got the guide about DOD for these products.

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In these years, increase of wastes and exhaust of resource become major issues according to the progress of mass productive, mass consumptive and mass waste economic system. As the correspondence, the construction of the sustainable society is strongly required. For constructing such society, the consideration to 3R (Reduce, Reuse, Recycle) at the design stage of industrial products become very important. Especially, as concerns Reuse and Recycle, the improvement of disassembling property of the products is one of the most important things to be considered. In this study, we attempted to investigate Disassembly-Oriented Design (DOD) for wheelchair, of which demand is estimated to increase due to the arrival of the aging society, by disassembling them. By disassembling them we understood the problems of the structure and compared the disassembling property of these products by applying the method of estimating products' disassembling property. Then we got the guide about DOD for wheelchair. In addition, by achieving DOD, the alternation of design in accordance with Time Place and Occasion (TPO), like ceremonial occasions, is considered to become easily at the using stage. In this paper, we also proposed the new concept of wheelchair which took both environment and welfare into consideration.

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Recently. a lot of environmental problems became obvious. Especially, waste problem is very serious. In this condition, some events adopting "Environment" as its slogan have come to be held. In those events, however, the situation of waste generation and the data of waste treatment have not been developed yet. So, we took "Kitakyushu Expo 2001" for instance and investigated the waste generation. And we made a study on the effectiveness of environmental considerations. As a result, we found 1) amount of waste generation in "Kitakyushu Expo 2001" is less than half that in the past expo because of the efforts to the reduction of waste generation (ex. use of returnable dishes), 2) the effectiveness of environmental considerations in the event is confirmed. So, we think environmental considerations like this are required in the future event (ex. Aichi Expo 2005).

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Recently, a lot of environmental problems became obvious. Especially, waste problem is very serious. In this condition, some events adopting "Environment" as its slogan have come to be held. In those events, however, the situation of waste generation and the data of waste treatment have not been developed yet. So, we took "Kitakyushu Expo 2001" for instance and evaluated waste treatment system with LCA method. Then, we use the Environmental Load Point (ELP) for index. As a result, we found 1) ELP for recycling is far less than that for not recycling on the kind we could calculate ELP. so it is confirmed that recycling is environmental friendly, 2) "the Zero Emission System" in this event reduced the environmental load in treating each kind of waste.

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End of Life Vehicles (ELV) are produced five million cars a year in Japan. New low for ELV treatment will be enforced in 2004 to recover the material and reduce the load to landfill. The aim for recycle is 95% and reduction of residue to landfill is one fifth of 1996. This paper introduces the new technology, Pyrolisis and melting system, to achieve the recycle rate 95% and reduction of residue one fifth. The pyrolysis and melting plant is operating over than four years. The materials recovered from the plant are slag which can be used as road construction material and metals which don't rust and molten. The material to be deposit in landfill is only flue gas cleaning residue. The recycle rate becomes 95.4% and the reduction becomes one thirty-second based on the operation data.

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