• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.261-273
• /
• 2004

An in-hole seismic method has been developed to meet the requirement of economical testing cost and practicality in engineering practice to measure dynamic soil properties. The in-hole prove developed herein is small and light enough to be fit in three-inch boreholes and to be handled with bare hands. And author modified the existing equipment for the convenient purpose. In addition, the best damper suited to in-hole test was also developed. The performance of the source has been evaluated through extensive cross-hole tests and in-hole tests at various sites.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.132-137
• /
• 2000

차량 개발에 있어서 승차감(Ride)과 조향성능(Handling)의 평가는 차량의 동적 성능을 판단하는 주 인자인데, 차량업계에서는 이들 평가의 대부분을 주관적인 방법에 의존하고 있다. 최근에는 주관평가의 문제점을 해소하기 위해 차량의 동적 거동을 직접 측정함으로써 평가를 객관화하려는 시도가 많이 행해지고 있다. 본 연구에서는 숭차감 평가를 위한 정량화 지수를 개발하는데 있어서 저해 요인들을 분석하고 이에 대한 해결방안을 제안함으로써 측정된 물리량을 이용하여 주관평가 결과를 대체할 수 있는 방안을 정립하고자 한다. 우선 정적, 동적 승차감에 대한 모형을 통해서 승차감 정량화의 한계와 기존의 승차감 평가지수에 대해 고찰하고, 실제 차량 시험에서 얻어진 주관 평가치와 측정 가속도간의 상관관계 정립을 통해 관계식을 수립하는 방안에 대해 서술하고자 한다. 이 과정에서 주행시 간헐적으로 들어오는 충격성 입력을 처리하는 방법도 함께 논하였다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.15 no.6
• /
• pp.63-69
• /
• 2011

The Smart UAV must have the control characteristics of propulsion system necessary for both rotary aircraft and fixed wing aircraft though it equips turbo-shaft engine. To develop an electronic engine controller in the future, it is necessary to accumulate the experience of engine operation and data of tilt rotor aircraft. For this purpose, the computer programs which predict engine performance in the steady state and transient state can be utilized for the supplementation of flight test data. In this work, we developed a dynamic analysis program using engine performance data gathered during the flight tests. In addition the accuracy of the program was verified through comparison with flight test data and the results of steady-state performance analysis program.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2005.09a
• /
• pp.155-175
• /
• 2005

Soil and rock dynamic properties such as shear wave velocity (VS), compressional wave velocity (VP) and corresponding Poisson's ratio ( v ) are very important geotechnical parameters in predicting deformational behavior of structures as well as practicing seismic design and performance evaluation. In an effort to measure the parameter efficiently and accurately, various bore-hole seismic testing techniques have been, thus, developed and used during past several decades. In this study, cross-hole seismic testing technique which is known as the most reliable seismic method was adopted for obtaining geotechnical dynamic properties. To perform successfully the cross-hole test for rock as well as soil layers regardless of the ground water level, spring-loaded source which impact laterally a subsurface ground in vertical bore-hole was developed and applied at three study areas, which contain four sites composed of two existing port sites and two new LNG storage facility sites. The geotechnical dynamic properties such as VS, VP and v with depth were efficiently determined from the laterally impacted cross-hole seismic tests at study sites, and were provided as the fundamental parameters for the seismic performance evaluation of the existing ports and the seismic design of the LNG storage facilities.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.04a
• /
• pp.130-131
• /
• 2011

In the present work, a synchronization test system for variable nozzle is described. Variable nozzles are used to enhance the effectiveness of aircraft engines at various altitudes. The synchronization test system was developed to verify the dynamic characteristics and synchronization of variable nozzle mechanism including flaps. The system with a variable nozzle was analyzed, before its fabrication, by a multi-body dynamics analysis software RecurDyn. The newly developed test system is being used to show the synchronization capability of a variable nozzle system.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.6
• /
• pp.505-513
• /
• 2021

We propose an autonomous mission management software design and verification technique for unmanned aerial vehicles to autonomously mitigate dynamic situation changes occurred in the inside and outside of an aircraft in compliance with the mitigation priority order. The proposed autonomous mission management software is designed in a modular architecture that consists of concurrently executing multiple threads. To verify it, we suggest three verification steps: 1) software integration by checking the expected request/response messages between the threads for all possible dynamic situation changes; 2) integration test to verify the software functionality; 3) performance test to verify the quantitative software performance. Especially, the software integration test environment is built and utilized to carry out the integration and performance tests.

• Korean Journal of Construction Engineering and Management
• /
• v.24 no.4
• /
• pp.14-24
• /
• 2023

The purpose of this study is to develop a prototype curtain wall with improved seismic performance and to verify the seismic performance by conducting an inter-floor displacement test. To this end, a prototype of the curtain wall was manufactured and a displacement similar to the earthquake load was induced, and then the damaged state of the curtain wall was checked. As a result of the first test, the frame and glass of the curtain wall were not damaged, but the Weather Sealant was partially damaged. As a result of the second test, there was no problem of glass breakage in seismic class (special), seismic class (I), seismic class (II), and AAMA 501.6. Through this experiment, the seismic performance of the curtain wall prototype was verified.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.4_1
• /
• pp.77-85
• /
• 1992

The Pseudo-dynamic test is a new experimental technique for simulating the earthquake response of structures or structural components in the time domain. It is especially efficient for testing specimens that are too large, heavy or strong to be tested on a shaking table. But, in general, the responses obtained in the Pseudo-dynamic test can be distorted by the experimental errors inevitably during control and measurement procedures. The studies are to investigate the effects of the experimental errors on the Pseudo-dynamic responses and apply a correction method to the Pseudo-dynamic testing algorithm. It is shown that the corrected responses using the equivalent energy compensation method are in a good correlation with the theoretical ones. Thus, the corrected Pseudo-dynamic responses could be reliable for evaluating the seismic performance of structural systems.

• Journal of Navigation and Port Research
• /
• v.46 no.3
• /
• pp.168-178
• /
• 2022

In this study, the resistance test, the vertical static angle of the attack test and VPMM test will be conducted to estimate the maneuverability of underwater vehicles with ahead propeller. The vertical static test will be conducted within the range of -40deg to 40deg, to investigate the cross-flow drag at high incidence angles. The tests will be conducted by dividing the propeller rotation into a case in which the propeller rotates at a specific rpm, and a case in which the propeller rotates naturally, according to the towing speed. Hydrodynamic coefficients of vertical direction will be estimated by the captive model tests. Additionally, the vertical dynamic stability index based on estimated hydrodynamic coefficients will be calculated and the impact of the propeller revolution state on the index will be investigated. The results are expected to be used as reference test data for underwater vehicles with ahead propeller.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.230.1-230.1
• /
• 2012

본 논문에서는 대구경 광학탑재체의 조립, 정렬 및 시험에 사용되는 고정밀, 고안정 짐발장치의 개발에 대해서 소개하고자 한다. 광학탑재체의 광학시험을 위해 사용되는 짐발장치는 광축높이를 유지하기 위해서 높이조절이 가능해야하고, 조립과정과 광학시험과정 그리고 시험 후 광학탑재체를 짐발 장치로부터 분리하기 위해 수평상태와 수직상태로의 회전이 가능해야 한다. 광학측정 시험과정 중에 결상위치의 미세한 조절을 위해 광학탑재체를 수평상태에서 상하좌우 정밀한 회전이 가능해야한다. 우주궤도환경 하에서 성능측정을 위해 열진공체임버 안에서의 광학시험이 필요하므로 짐발장치를 구성하는 재질은 모두 진공사용이 적합한 것이어야 한다. 광학측정 중에 측정설비주변에서부터 인가된 외란은 광학시험과 같은 민감한 시험에서는 철저하게 제거되어야 하는데, 이와 관련하여 짐발장치의 광학측정시험형상에서의 고유진동수와 같은 동적 특성도 설계과정에 반영하여 안정적인 측정 장치가 되도록 고려되어야 한다.