• 제어로봇시스템학회논문지
• /
• 제19권4호
• /
• pp.334-340
• /
• 2013

Using a relationship between step length and accelerometer output, step length can be estimated. In this paper, we propose a new step length estimation algorithm, which can be used both for the plane and the slope by compensating the slope angle. The slope angle is estimated using a barometer and the slope angle is compensated by observing how the slope affects the step length estimation. The proposed algorithm is verified using five adult man walking data, where the average length error is about 3% regardless of the slope.

• 대한전자공학회논문지
• /
• 제27권12호
• /
• pp.1841-1851
• /
• 1990

Self-aligned gate GaAs MESFETs using ion beam deposited tungsten applicable to GaAs LSI fabrication process have been fabricated. Silicon implanted samples were annealed using isothermla two step RTA process and conventional one step RTA process. The electrical and physicla characteristics of annealed samples were investigated using Hall and I-V measurements. As results of measurements, activation characteristics of the isothermal two step RTA process are better than those of one step annealed ones. Using the developed processes, GaAs SAFETs (Self-Aligned Gate FET) have been fabricated and electdrical characteirstics are measured. As results, subthreshold currents of SAGFETs are 6x10**-10 A/\ulcorner, that is compatible to conventional MESFET, maximum transconductances of 0.75\ulcorner gate MESFET using one step RTA process and 2\ulcorner gate MESFET using isothermal two step RTA process are 18 mS/mm, 41 mS/mm respectively.

• 한국전자거래학회:학술대회논문집
• /
• 한국전자거래학회 1999년도 학술대회지 vol.2
• /
• pp.509-519
• /
• 1999

STEP은 제품모델 정보를 서로 다른 CAD 시스템에서 교환할 수 있게 하기위한 중립형식의 국제표준으로서 CALS/EC의 구현을 위해 필수적인 핵심기반 기술이다. 선박 관련 STEP은 지금까지 미국과 유럽의 여러 연구사업을 통해 개발되어 오고 있으며 AP215(선박구획배치), AP216(선박선형), AP217(선박배관), AP218(선박구조)은 올해 안에 CD(Committee Draft) 안이 완성될 예정이다. 우리나라는 일본과 함께 세계 조선시장을 양분하고 있는 조선 강국이면서도 관련 정보기술의 낙후로 STEP 기술 개발에는 미온적이었으나 최근 선박해양공학분소에서 과기부의 특정과제로 수행하는 KS-STEP 과제를 통하여 ATS 318 (AP218, 선박구조의 ATS) 개발 책임을 맡게되어 본격적인 관련 연구를 시작하게 되었다. 여기에서는 ATS 318 개발을 위해 조선소와 선급 등 선박관련 업체들의 기술 정보 교환 프로세스를 분석하여 나타내었다. 각 프로세스에서 요구되는 기술정보의 형태와 추상화 정도가 분석되고 선박 STEP AP들의 기반 구조인 SCM(ship common model)에서 어떻게 그들 특성을 지원해야 하는지를 검토하였다.

• 한국주거학회논문집
• /
• 제11권4호
• /
• pp.9-22
• /
• 2000

The residential mobility and the housing choice procedures play a significant role on households welfare. This procedure consists of $\circled1$ Moving motives step, $\circled2$ Housing search step, $\circled3$ Assessment of housing alternative step, $\circled4$ Choice and evaluating after choice step, $\circled5$ Intention to move step. There are linkages with each step. The higher the level of moving motives, the higher the level of housing search efforts. The higher the level of housing search efforts, the higher the level of housing alternative evaluating. The higher the level of housing alternative evaluating, the higher the level of housing satisfaction after they choose a house. The higher the level of housing satisfaction after they choose a house, the lower the level of intention to move. So the whole procedure of housing choice among consumers has a main streaming throughout the steps.

• 한국해양공학회지
• /
• 제7권2호
• /
• pp.150-161
• /
• 1993

원초변수를 이용한 Navier-Stokes 방정식의 수치계산기법을 개발하고, 이를 응용하여 backward facing step의 층류 유동을 계산하였다. 직교좌표계에서의 비압축성 Navier-Stokes방정식을 풀기위해 시간과 공간항을 2차 정도의 유한 차분을 사용하여 이산화하였고 비교차격자계를 사용하여 양해법으로 수치 계산하였다. 운동량방정식과 연속방정식으로 부터 유도된 압력방정식(pressure-poisson equation)을 이용하여 무발산 조건을 만족시켰ㄲ다. Backward facing step의 층류 유동을 100.$\leq$R$_e$$\leq$1000 범위에 대해서 수치 계산하였으며 실험결과와 잘 일치하는 결과를 구할 수 있었다. 특히 step뒤에서 생기는 박리구간의 길이는 다른 계산결과들보다 실험치에 가까운 값을 얻을 수 있었으며, Re가 600보다 클때는 위쪽 벽에 또 다른 박리 유동이 발생되는 현상이 예측되었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2001년도 춘계학술대회 논문집
• /
• pp.367-372
• /
• 2001

Feature restoration is that restore feature to 3D solid model using the feature information in STEP AP224. Feature is very important in CAPP, but feature information is defined very complicated in STEP AP224. This paper recommends the algorithm of extraction the feature information in physical STEP AP224file. This program import STEP AP224 file, parse the geometric and topological information, the tolerance data, and feature information line-by-line. After importation and parsing, store data into database. Feature restoration module analyze database including feature information, extract feature information, e.g. feature type, feature's parameter, etc., analyze the relationship and then restore feature to 3D solid model.

• 대한전자공학회논문지
• /
• 제23권6호
• /
• pp.888-894
• /
• 1986

In this paper, a phase locked loop control system is designed to have high performance and stability in a 2-phase bifilar winding PM step motor. The BODE diagram analysis method is used to improve the stability and dynamic characteristic of the closed loop control system. Also, a PLL servo is used to accomplish high-precision speed and to attain smooth ness. In applying the PLL control to the step motor, a new design method is suggested to solve the control problem which occurs as a result of the limited maximum acceleration of the step motor. A simple design method is suggested without using the complicated multi-step characteirstic of the step motor in constant voltage driving. Computer simulation results agree clorelg with experiments, indicating that the PLL servo system of the step motor designed is very useful.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1997년도 춘계학술대회논문집
• /
• pp.179-182
• /
• 1997

One-step inverse methods based on deformation theory causes some amount of error. The amount of error is generally increased as the deformation path is more complex. As a remedy, a new three dimensional multi-step inverse method is introduced for optimum design of blank shapes and strain distributions from desired final shapes. The approach extends a one-step inverse method to a multi-step inverse method in order to reduce the amount of error. The algorithm developed is applied to square cup drawing to confirm its validity by demonstrating reasonably accurate numerical results.

• 산업기술연구
• /
• 제19권
• /
• pp.59-65
• /
• 1999

This study is to analyze turbulent flow over a backward-facing step in a rectangular duct. The side wall effects on the internal flow were determined by varying the aspect ratio(defined as the step span-to-height ratio) from 1 to 20. In the flow behind a backward-facing step, separation, recirculation and redeveloping is occurred frequently. These phenomena appear in a particular variation by varying the aspect ratio. The results show that the aspect ratio has an influence on the velocity and reattachment length. When the AR is increased, the reattachment length is increased. For 6 over aspect ration, the rate of increase is decreased. The length of recirculation in the upper corner is increased, as the increase of aspect ration. It's width is not changed in the variation of aspect ration. The transverse, streamwise and spanwise velocities were decreased along the flow down stream of the step.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
• /
• pp.258-260
• /
• 1995

This paper deals with the voltage unbalance of DC link voltage in series connected two 6-step inverters with double chopper preregulator. Each output of the 6-step inverter is connected to each transformer. The secondary windings of one of the transformers is zig-zag connected and the other star connected. The secondary terminals of the two transformers are series connected which makes 12-step output voltage waveform. In this case, the characteristics of the two transformers are rather different each other. The difference results in the voltage unbalance of the two 6-step inverter input capacitor voltages which make the DC link voltage. The degree of the voltage unbalance is analysied with the variations of load power, load power factor and % impedance of the transformer.