Recently, It is proceeding the project of offshore structures in the many contury. A hybrid boundary-integral method is developed for computing wave forces on floating bodies. In this method, using the cylindric boundary for deviding elements, it is convenient to analysis but is difficult to apply to the rectangular or slender bodies. Thus, in this paper, I propose the new method by using the fictitious vertical cylinder of arbitary cross-section and shows results of the numerical analysis for testing.

This objective of this paper is to investigate the evaluation and indiction of human thermal comfort in building environment. The issue of defining the boundaries of acceptable thermal comfort conditions in buildings and urban may have significant implication for building design and also may have urban design by climate considerations. And then it is to apply the thermal comfort condition to environmental design by using passive methods in Korea. Since 1920. architects have conducted studies to measure thermal comfort in houses under hot and humid conditions, while industrial hygienists have studied the effects of temperature and humidity on the performance of factory workers. Thermal comfort can be influenced by many variables. This paper conducted to review the previous researches and the human heat balance equation, and to analyse in order to reveal the meaning and usage of the thermal comfort index in two traditional essays, Fanger's PMV and Gagge's ET* Their comfort indexes compared with each other. They were based on human heat balance equation and psychological and physiological responses in the laboratory tests. The researchers and the architectural engineers using thermal comfort index shall be careful in decided the use of indexes and be necessary to recognize the value concept of the design criteria for thermal comfort. Therefore, The opinion of the authors is that different comfort standards have to apply for each building and urban with different climatic conditions.

After studying several methods of the application a device of a treated sewage in anticipation of the future shortage of the duty of water, we could have some conclusion as the following : Advanced treatment systems arc essential prerequisites in reusing a treated sewage. And in a short term, the application of reusing a treated sewage should go first to new building areas near the sewage but for the long run, it should cover the whole area of Taegu, it is desirable that the pipe line networks which include dual water systems as well as water supply should be spread throughout the whole city. The city authorities have to make every effort to step up publicity activities on this plan to all the citizens and building owners to steadily carry out this project and encourage private constructors to participate with the help of SOC. And for the long run, it is desirable that the application of reusing a treated sewage should be obligatory.

Results of two-part wedge analysis and centrifuge test executed by Zornberg et al. were compared for geotextile-reinforced slope stability. For two-part wedge analysis results of two cases, a frictional case considering internal friction of soil as interwedge friction and a nonfrictional case not considering, were also compared and evaluated. The analysis was based on limit equilibrium and two-part wedge was divided into slices as many as the number of geotextiles to obtain a maximum tension distribution mobilized in reinforcements. A significant observation was that the distribution was a triangular shape with maximum tension of geotextile at a transit point of interwedge. The number of geotextiles and failure surface of frictional case were reasonable and more comparable to results of the centrifuge tests than those of nonfrictional case. Therefore it can be said that two-part wedge analysis is recommendable for design analysis of reinforced slopes if an interwedge angle is regarded to be an angle of internal friction in soil.

In general, FORTRAN is used for numerical analysis and OPS5 or LISP is used for expert systems, This causes problems at the interface because the various applications require different computing languages or environments. This paper describes the approach used to take AutoCAD as a user-interface for an existing finite element structural analysis package. Some principles concerning database management related to data-exchange interface of pre- and post-processing system for FORTRAN structural analysis program are discussed, and numerical examples demonstrate the power of the combination of these programs.

This study aims at the development of the techniques for the rainfall forecasting in river basins by applying neural network theory and compared with results of Multivariate Model (MVM). This study forecasts rainfall and compares with a observed values in the San Chung gauging stations of Nakdong river basin for the rainfall forecasting of river basin by proposed Neural Network Model(NNM). For it, a multi-layer Neural Network is constructed to forecast rainfall. The neural network learns continuous-valued input and output data. The result of rainfall forecasting by the Neural Network Model is superior to the results of Multivariate Model for rainfall forecasting in the river basin. So I think that the Neural Network Model is able to be much more reliable in the rainfall forecasting.

The variety of crystalline structure and mechanical properties of PP filament treated with dry heat treatment at different draw ratio has been studied. Crystalline structure and mechanical properties of annealed PP filament at different draw ratio has been examined by XRD, UTM, and density method. Heat treatment has been carried out $100^{\circ}C$, $120^{\circ}C$ $140^{\circ}C$ for 30min. in dry oven. From the results of this study, it found the following facts. It was found that the crystallinity and crystallite size of (110) plane of sample were increased with increasing of annealed temperature and draw ratio. The crystalline form of annealed sample which was undrawn showed ${\alpha}$, ${\beta}$ mixing form below $120^{\circ}C$ and showed ${\alpha}$ form at $140^{\circ}C$. But the crystalline form of annealed sample which was drawn showed ${\alpha}$ form at $120^{\circ}C$. Initial modulus and tensile strength were increased with increasing of annealing temperature, and the degree of orientation was decreased with decreasing of annealing temperature.

The aim of this study is to enhance the abrasion of the hydrolyzed polyethylene terephthalate(PET) fabrics by using microwave energy. In other to achieve the aforementioned objectives, PET fabrics were hydrolyzed in NaOH solution by using abrasion method such as dipping, microwave-dipping, pad steam-dry, and pad microwave-dry, and then abrasion of the hydrolyzed PET fabrics was calculated and investigated. As a result obtained form this study, the abrasion of the hydrolyzed PET fabrics is directly proportional to hydrolyzed time and NaOH concentration. And also, microwave-dipping method and pad microwave-dry method showed remarkable abrasion effect than the others.

Shake mixing has been widely used in cell culture. The mixing performance for shake mixing, however, has not been reported quantitatively. The critical circulating frequency and the power consumption for complete suspension of particles, based on the definition of Zwietering, were measured in a shaking vessel containing a solid-liquid system. The critical suspension frequency was correlated by the equation from Baldi's particle suspension model modified with the physical properties of the particles. Critical suspension frequency was correlated as following ; $$N_{JS}={\frac{0.58\;d{_p}^{0.06}(g{\Delta}{\rho}/{\rho}_L)^{0.004}X^{0.03}}{D^{0.35}d^{0.17}{\upsilon}^{0.04}}}$$ The power consumption at the critical suspension condition in the shaking vessel was less than that in an agitated vessel with impeller.

A cellulose acetate membrane containing silver nitrate was prepared by gelatinizing in water at $2^{\circ}C$ after evaporating solvent from the casting solution on a glass plate. Permeation experiments for oxygen and nitrogen were conducted in the ranges of temperature, $5-40^{\circ}C$ and pressure difference, $1-5kg/cm^2$ in order to investigate the effects of temperature and pressure difference on permeation characteristics of the membrane. When the evaporation time was increased, the permeability of oxygen decreased but the separation factor of oxygen against nitrogen increased since a more dense layer was formed on the membrane surface. When the silver nitrate was added, the permeation flux was doubled and the separation factor was improved from 3.0 to 3.3. This implies that silver nitrate acts as an oxygen carrier in the membrane.

The paper describes a robust adaptive control algorithm for induction motor drive without speed sensor at low speed range. The control algorithm use only current sensors in a space vector pulse width modulation within loop control with rotor speed estimation and voltage source inverter. On-line rotor speed estimation is based on utilizing parallel model reference adaptive control system. MRAC of the modified flux model for flux and rotor speed estimator uses dual-adaptation mechanism, ${\omega}_r$ and ${\omega}_e$ scheme. The estimated flux components in the model can be compensated from the effects of offset errors on pure integrals. It can be compensated to the parameter variations and torque fluctuation with speed estimation in less then 10 rad/sec. In a simulation, the proposed induction motor control algorithm without speed sensor at very low speed range are shown to operate very well in spite of variable rotor time constant and fluctuating load without change the controller parameters. The suggested control strategy and estimation method have been validated by simulation study, and it proposed the designed system for the implementation using TI320C31 DSP/ASIC controller.

The paper describes a implementation of space vector pulse-width modulation voltage source inverter and interfacing of DSP using field programmable gate array(FPGA) for a induction motor vector control system. The implemented chip is included logic circuits for SVPWM, dead time compensation and speed detection using Quick Logic, QLl6X24B. The maximum operating frequency and delay time can be set to 110MHz and 6 nsec. The designed Application Specific Integrated Circuit(ASIC) for SVPWM can be incorporated with a digital signal processing to provide a simple and effective solution for high performance induction motor drives with a voltage source inverter. Simulation and implementation results are shown to verify the usefulness of ASIC in a motor drive system and power electronics applications.

본 논문에서는 응용 주문형 집적회로 (ASICs)로 구현되는 신호처리기의 비용 예측 방법을 소개한다. 비용 예측은 디자인의 초기 단계에서 다양한 설계 사양들을 비교하여 성능과 비용 면에서 최적의 설계를 찾는데 도움을 준다. 본 비용 예측 방법은 Computer-Aided Design 도구들을 이용하여 시스템 동작 표현으로부터 시작하여 시스템 분할과 상위 수준 합성을 거쳐 레지스터 전송 수춘 단계에서 비용 예측을 실행한다. 사례 연구로 SWIR focal plane으로부터 생성되는 신호를 처리하는 신호처리기의 비용 예측을 실험한다. IBM 1.0 마이크론 기술의 CMOS 표준 셀을 적용하여 실험을 한 결과 각 채널로부터 전달되는 데이터를 실행하기 위해서는 3개의 칩이 필요했다.

The interaction of weak normal shock wave with turbulent boundary layer in a supersonic nozzle was investigated experimentally by wall static pressure measurements and by schlieren optical observations. The lime-mean flow in the interaction region was classified into four patterns according to the ratio of the pressure $p_k$ at the first kink point in the pressure distribution of the interaction region to the pressure $p_1$ just upstream of the shock. It is shown for any flow pattern that the wall static pressure rise near the shock foot can be described by the "free interaction" which is defined by Chapman et al. The ratio of the triple point height $h_t$ of the bifurcated shock to the undisturbed boundary layer thickness ${\delta}_1$ upstream of the interaction increases with the upstream Mach number $M_1$, and for a fixed $M_1$, the normalized triple point height $h_t/{\delta}_1$ decreases with increasing ${\delta}_1/h$, where h is the duct half-height.

It is already known that hardness value of cold-forged product is in close conjunction with its effective strain. This paper presents the method to predict the relation between effective strains and hardness values by using FE-simulation of hardness test from the conception that hardness indicates resistance to plastic deformation. The results of FE-simulation for the material with pre-strain arc compared with those of experiments of the references to show the feasibility of the proposed method.

Package crack caused by the soldering process in the surface mounting plastic package is evaluated by applying the energy release rate criterion. The package crack formation depend on various parameters such as chip set, chip size, package thickness, package width, material properties and the moisture content etc. The effects of chip set and the other parameters were estimated during the analysis of package cracks which were located in the edge of the upper interface of the chip and the lower interlace of the die pad. From the results, it could be obtained that the more significant parameters to effect the chip set are chip width.

Combustion Characteristics of the wood chips(balsa chips) were experimental studied as fundamental investigation of the thermal recycle system of the urban dust. The urban dust contains plastics vegetable and lot of wood material. Then, a wood was chosen as an example of the component of urban dust. A small wood chip was burned in a electric furnace and mass reduction rate during volatile and combustion states were recorded by the micro-electric balance and the combustion flame shape took a photograph by video camera at the mass of wood chips and ambient temperature in the furance. Ignition delay took the minimum value when the mass of the test chip was 0.3g. When a mass of the test chip was smaller then 0.001g, combustion with flame did not burnt.

An in-process extraction method of the ground surface roughness is a bottle-neck and essential field in conventional machining process. We define the D.A.R.F(Dimensionless Average Roughness Factor) that has a roughness characteristic of ground surface. D.A.R.F include the absolute average and the standard deviation values which are the analytic parameters of the AE(Acoustic Emission) signal generated during the grinding operation. The theoretical equation between the surface roughness and the D.A.R.F has been derived from the linear regressive analysis and verified its availability through the experimentation on the surface grinding machine.

In this study, single cylinder engines with different tumble ratio were made to find out in-cylinder fluid motion and flame propagation. Tumble ratio derived from the steady state flow rig test. Flame propagation speed was obtained using cylinder head gasket ionization probe and the piston ionization probe. And the combustion pressure in cylinder was measured to analyze the combustion characteristics. In case of high tumble engine, BSFC and BSHC were decreased and BSNOx was increased at part load test. Also BMEP and combustion peak pressure was increased at full load test. Tumble flow motion had an great effects on initial burning period rather than main burning period in part load test.

Crane operation for transporting heavy loads causes swinging motion at the loads. This sway causes the suspension ropes to leave their grooves and leads to possibility of serious damages. Generally crane is operated by expert's knowledge. Therefore, a satisfactory control method to supress object sway during transport is indispensible. The dynamic behavior of the crane shows nonlinear characteristics. when the length of the rope is changed the crane is time varying system and the design of anti-sway controller is very difficult. In this paper, the nonlinear dynamic model for the industrial overhead crane is derived. and the feedback gain matrix based on the pole-placement method is proposed to supress the swing motion and control the position of the crane. The performance of the controller for the crane model is simulated on the personal computer.

When Automobile runs high velocity, it causes sleepy velocity profile then that generates lift force and drag force. Lift force reduce tire friction force. Drag force increase consumed power. For improve automobile performance, reduction of Lift force and Drag force was seriously considered. It measured experimently using wind tunnel, numerically using numerical analysis. Finite difference method is using difference equation and simplifed mesh. This method require less calculation time and computer power than other method.

For an unmanned machining system, the control and disposal of chips is one of the most serious problems at present. In order to perform chip control, feed/land length($F_L$) was introduced, and using this parameter, the cutting performance and chip breaking characteristics of groove-type and the land -angle-type chip formers were assessed. The specific cutting energy consumed and the shape of broken chips with its breaking cycle time were evaluated to find out the ranges of $F_L$ value where efficient cutting and effective chip breaking could be achieved. The C type chip was found to be the most preferable from the view point of cutting efficiency.

Closed-die forging of spline was analysed using the upper bound elemental technique, Two different forging methods, denoted here as side extrusion-forging and upset forging, were proposed, The kinematically admissible velocity fields for each of the forging methods, which could express trapezoidal, rectangular and serration tooth forms, were presented. Upper bounds to forging loads and deformed configurations were predicted using the velocity fields. Theoretical results were compared with experimental ones. Experiments with lead were carried out at room temperature where grease was used as a lubricant. The present investigation revealed that analytical forging loads were reduced by using the side extrusion-forging but the upset forging could improve configuration of the final forged splines.