• 소음진동
• /
• 제10권5호
• /
• pp.873-879
• /
• 2000

Experimental investigation was conducted to study the effects of pitch angle maximum camber on the performance and noise of an axial-flow fan used in outdoor-unit of air -conditioner. For this study the axial-flow fan whose pitch angle can be varied was made and the Specific sound Pressure Level and other coefficients were measured using the anechoic fan tester. It is found that pitch angle affects more severly than the maximum camber on the fan performance. On the while the maximum camber affects much on the specific sound power level. Present results show that it is important to choose the optimum pitch angle and maximum camber to design the high-performance and low-noise axial-flow fan and specific noise measured in the anechoic fan tester can be sued effectively for the design of low-noise fan.

• 한국자동차공학회논문집
• /
• 제15권3호
• /
• pp.114-123
• /
• 2007

We are going to propose equations for stable static and endurance strength design of driveshafts. It is very important to decide the contact normal stress of internal components of CV joints. We can estimate the strength, torque capacity, endurance life of CV joints from contact normal stress by presented equation in this paper. Besides it can be shown the equation for shaft design.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 ITC-CSCC -1
• /
• pp.351-354
• /
• 2000

In the past, we proposed an IDDQ testable design method for static CMOS PLA circuits. All bridging faults can be detected in NOR planes of our testable designed PLA circuits by IDDQ testing with 4 kinds of test input vectors which are independent of the logical functions to be realized. However, the testable designed PLA circuits consume large power in the normal operation. In this paper, a new IDDQ testable design method is proposed and evaluated by some experiments. The experimental results show that the PLA circuit designed with our method can work with low power consumption than the previous one.

• 항공우주기술
• /
• 제1권2호
• /
• pp.32-44
• /
• 2002

전기체 정적시험 시험을 수행하기 위해 개발된 기술과 시험치구 설계에 대하여 설명하였다. 개발된 기술은 치구설계에 설계기준으로 사용하는 설계기준하중 산출기술, 하중부가 장치 설계기술, 중량보상장치 설계기술, 시험체 자세제어장치 설계기술, 시험장비 구성설계 및 과하중방지 기술이다. 이와 같이 개발된 시험기술을 적용하여 설계된 시험치구를 이용하여 고등훈련기 전기체 정적 시험인 설계제한하중 시험이 성공적으로 수행되었다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
• /
• pp.125-130
• /
• 2002

This paper examines the application of high voltage static var compensator(SVC) with cascade multilevel inverter which employs H~bridge inverter(HBI). The SVC system is modeled using the d-q transform which calculates the instantaneous reactive power. This model is used to design a controller and analyze the SVC system. From the mathematical model of the system, the design procedures of the circuit parameters Land C are presented in this thesis. To meet the specific total harmonic distortion(THD) and ripple factor of the capacitor voltage, the circuit parameters Land C are designed. Simulated and experimental results are also presented and discussed to validate the proposed schemes.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
• /
• pp.61-63
• /
• 2015

In the low pressure selective catalytic reduction (LP SCR) system, the uniformity of both ammonia concentration and exhaust gas flow at the SCR catalyst layer are important design factor for the efficient SCR-deNOx performance. According to the shape of the guide vane and static mixer, numerical simulations were conducted to analyze flow patterns and finally to find out the appropriate alternative for uniform flow at the front of catalyst in the real scale LP SCR reactor. The variations of gas velocity and ammonia concentration were quantitatively evaluated. Based on the present results, the shape was devised to satisfy the design criteria.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2003년도 춘계 학술발표회논문집
• /
• pp.224-231
• /
• 2003

The purpose of this study is to review and validate the seismic analysis procedures of turbine-generator foundation specified in the Korea Building Code which adopts equivalent static analysis. Typical machines and foundations were chosen and various kinds of parametric studies were peformed and the results were compared with the detail dynamic analysis. The general trend of the study results showed that the most of the computed responses of equivalent static analysis are smaller than those of the dynamic analyses(response spectrum analysis and time history analysis), which implies the existing seismic analysis technique using the existing Building Code may give unconservative design results. The results also showed that the seismic loads are one of the governing design parameters of the turbine-generator foundations.

• Earthquakes and Structures
• /
• 제1권2호
• /
• pp.163-175
• /
• 2010

The vertical axis through the modal center of rigidity (m-CR) is used for interpreting the code torsional provisions in the design of eccentric multi-story building structures. The concept of m-CR has been demonstrated by the author in an earlier paper and the particular feature of this point is that when the vertical line of the centers of mass at the floor levels is passing through m-CR, minimum base torsion is developed. For this reason the aforesaid axis is used as reference axis for implementing the code provisions required by the equivalent static analysis. The study examines uniform mixed-bent-type multistory buildings with simple eccentricity, ranging from torsionally stiff to torsionally flexible systems. Using the results of a dynamic response spectrum analysis as a basis for comparisons, it is shown that the results of the code static design are on the safe side in torsionally stiff buildings, but unable to predict the required strength of bents on the stiff side of systems with a predominantly torsional response. Suggestions are made for improving the code provisions in such cases.

• 한국지반환경공학회 논문집
• /
• 제18권9호
• /
• pp.11-18
• /
• 2017

수치해석기법을 이용한 말뚝의 거동특성 예측방법은 정재하시험비가 고가이기 때문에 공사 전 말뚝의 거동을 예측할 수 있다는 장점으로 설계단계에서 널리 이용되고 있지만 그 신뢰성에 대한 연구는 부족한 실정이다. 본 연구에서는 실제 현장에서 말뚝의 거동과 수치해석으로 예측한 말뚝의 거동을 비교함으로써 수치해석 기법의 신뢰성을 검증하였다. 지반과 말뚝의 상호작용에 의한 말뚝의 거동을 정확하게 파악하기 위하여 정재하시험이 수행되는 지반에서 시추조사, 현장원위치시험 등을 통해 지반특성을 확인하였고, 실규모 정재하시험을 수행하여 말뚝의 거동특성을 분석하였다. 정재하시험이 수행된 방식과 동일하게 수치해석을 모사하여 재하시험과 동일한 하중단계에서 말뚝의 거동을 수치해석으로 모사하여 현장시험 결과와 비교함으로써 수치해석 기법의 신뢰성을 검증하였다.

• 대한물리치료과학회지
• /
• 제26권1호
• /
• pp.45-53
• /
• 2019

Background: The purpose of present study was to examine the effect of ultrasound therapy and static stretching on hamstring length and balance. Design: Randomized Controlled Trial. Methods: A total of 30 adults in S college, Seongnam city, Gyeonggi-do, between the ages of 20-30 were randomly assigned to two groups. Group 1 (n=15) had ultrasound therapy, called US group. Group 2 (n=15) had static stretching, called SS group. Measurements were taken prior to starting the program and after completing the experiment using Finger to floor test and Active knee extension test to get the results of hamstring flexibility and the ability of static balance. Paired t-test was used to compare each group pre-test values to post-test values and to compare US post-test values to SS post-test values on PASW 18.0. Results: 1) Both hamstring SS group and US group had significant increase (p<.05) in Finger to floor test and Active knee extension test. 2) Dominant leg standing had significant change (p<.05) only in US group. 3) There was no significant difference between US group and SS group. Conclusion: Results showed that US group and SS group had an effect on changes in hamstring length (p<.05). However, they did not show a significant increase in static balance. Further effective studies on hamstring SS group and US group were needed based on this examination.