• 한국지진공학회논문집
• /
• 제15권5호
• /
• pp.11-24
• /
• 2011

고정반복법에 의한 암시적 HHT 시간적분법을 이용하여 3층 3경간 철근콘크리트 골조구조물을 수치해석모형과 물리적 분구조모형으로 나누어 실시간 하이브리드실험을 실시하였다. 물리적 부분구조모형으로는 1층 내부 비연성기둥 1개소가 선택되었고, 수치해석모형에 일축 방향의 지진하중을 시편이 심한 손상에 의하여 파괴에 이를 때까지 작용시켰다. 비선형 유한요소해석 프로그램인 Mercury가 실시간 하이브리드실험을 위하여 새로이 개발 및 적용되었다. 실험결과는 물리적 부분구조모형의 상부 수평방향 층간변위비를 OpenSees에 의한 수치해석시뮬레이션과 진동대실험의 그것과 비교하였다. 본 실험은 가장 복잡한 실시간 하이브리드실험 중의 하나이고, 하드웨어, 알고리즘 그리고 모형에 대한 기술적인 내용을 본 논문에 자세히 설명하였다. 수치해석모형의 개선, 물리적 부분구조 모형 접선강성행렬의 유한요소해석 프로그램에서의 평가 그리고 하중기반 보-요소의 요소상태결정의 연산시간을 줄이기 위한 소프트웨어의 개선이 이루어진다면 실시간 하이브리드실험과 진동대실험결과의 비교는 권장할 만하다. 그리고 "지진과 같은 동적하중하의 복잡한 구조물의 수치해석시뮬레이션"이라는 목적을 위하여 실시간 하이브리드실험은 동적하중에 대한 실험적 검증을 점진적으로 수치해석모형으로 대체하기 위한 저비용-고효율 실험법으로서의 가치를 충분히 가지고 있다고 할 수 있다.

• 한국콘텐츠학회논문지
• /
• 제12권6호
• /
• pp.68-77
• /
• 2012

최근 시스템 개발 환경이 싱글프로세서 기반의 환경에서 멀티프로세서 기반의 환경으로 변화됨에 따라 개발된 시스템 프로그램들이 멀티프로세서 기반과 싱글프로세서 기반에서 호환이 가능하도록 설계 및 구현의 중요성이 부각되고 있다. 특히, 실시간성이 중요시 되는 내장형 소프트웨어 분야 및 측정 장비와 같이 정밀성을 요구하는 분야의 경우 멀티프로세서 기반의 실시간성을 제공하기 위한 연구가 필요하다. 운영체제에 종속적인 실시간성은 운영체제에 따라 지원여부를 결정하는데, 범용 운영체제인 윈도우즈의 경우 실시간성을 지원하기 위해 RTX나 INtime과 같은 고가의 서드파티를 사용해야 한다. 그러나 서드파티를 사용함으로써 제품 개발 시 고가의 구입비용 및 유지보수 비용으로 인한 개발 비용의 증가를 초래하는 문제점이 발생한다. 이러한 문제점을 해결하기 위해서, 본 논문에서는 멀티프로세서 기반의 윈도우즈에 실시간성을 제공하기 위해 x86 아키텍처의 Local APIC를 이용하여 윈도우즈에 실시간성을 제공하는 RTiK-MP(Real-Time implant Kernel-Multi Processor)를 설계 및 구현하였고, RTiK-MP의 성능 검증 및 평가를 위하여 휴대용 점검장비를 이용한 성능 측정 결과를 분석한다.

• 한국산학기술학회논문지
• /
• 제21권9호
• /
• pp.229-237
• /
• 2020

본 연구는 실시간 온라인 시험방식을 고안하여 K대학교 간호학과 4학년 33명을 대상으로 2020년 1학기에 7차례의 시험을 실시한 결과를 공유하고, 실시간 온라인 시험에서의 공정성 확보방안을 제시하고자 시도되었다. 본 연구에서의 실시간 온라인 시험은 zoom cloud meetings를 활용하였다. 학생들이 PC나 노트북 중 한 가지 기기와 휴대폰으로 동시에 회의에 참여하도록 하였고, 교수자는 한 문제씩 화면에 실시간으로 띄워주며 비공개톡을 활용하여 답안을 수거하였다. 이러한 방식을 통해 학생들의 모니터 화면과 키보드, 마우스, 자세를 모니터링하고 통제하였다. 실시간 온라인 시험에 대한 설문조사 결과, 93.8%의 학생들이 전반적으로 공정하게 진행되었고 만족스럽다고 응답하였고, 90.6%의 학생들은 온라인 시험을 다른 사람에게 추천할 의향이 있다고 하였다. 다가오는 미래에는 원격강의와 온라인 시험이 보다 활성화될 것이므로 보다 공정하고 체계적이며 누구나 쉽게 활용할 수 있는 온라인 시험방식을 개발함으로써 점차 다른 시험으로도 확대시키려는 노력이 필요하다.

• 한국입자에어로졸학회지
• /
• 제14권4호
• /
• pp.107-119
• /
• 2018

In this study, we have developed a real-time monitoring device for measuring PM10 and PM2.5 of ambient aerosol particles. The real-time PM monitor (SENTRY Dust Monitor) uses the optical scattering method and has 16 channels in particle size. The laboratory and field tests were carried out to evaluate the developed SENTRY Dust Monitor. Arizona Test Dust particles were used as test particles in the laboratory test and the field test was carried out at the Jongno-gu Observatory in Seoul. The measurements of PM10 and PM2.5 concentrations obtained by SENTTRY Dust Monitor were compared with Grimm Dust Monitor (Model 1.108) and a beta ray gauge. It was shown that the PM10 and PM2.5 concentrations obtained by SENTRY Dust Monitor agree well with that of the reference devices. Based on the results obtained in this study, it could be concluded that the SENTRY Dust Monitor can be used as a PM monitoring device for real-time monitoring of the ambient aerosols.

• Journal of Mechanical Science and Technology
• /
• 제15권9호
• /
• pp.1248-1256
• /
• 2001

In this study, a test bed for vehicle longitudinal control is developed using a chassis dynamometer and real time 3-D graphics. The proposed test bed system consists of a chassis dynamometer on which test vehicle can run longitudinally, a video system that shows virtual driver view, and computers that control the test vehicle and realize the real time 3-D graphics. The purpose of the proposed system is to test vehicle longitudinal control and warning algorithms such as Adaptive Cruise Control(ACC), stop and go systems, and collision warning systems. For acceleration and deceleration situations which only need throttle movements, a vehicle longitudinal spacing control algorithm has been tested on the test bed. The spacing control algorithm has been designed based on sliding mode control and road grade estimation scheme which utilizes the vehicle engine torque map and gear shift information.

• 한국철도학회논문집
• /
• 제7권1호
• /
• pp.1-8
• /
• 2004

A newly-built inverter has to undergo a series of stress tests in the final stage of production line. This can be achieved by connecting it to a dynamometer consisting of a three-phase machine joined by a rigid shaft to a DC load machine. The latter is controlled to create some specific load characteristic needed for the test. In this paper a test method is proposed, in which no mechanical equipment is needed. The suggested test stand consists only of a inverter to be tested and a simulator converter. Both devices are connected back-to-back on the AC-side via smoothing reactors. The simulator operates in real-time as an equivalent load circuit, so that the device under test will only notice the behaviour of a three-phase machine under consideration of the load. In oder to prove rightness of the suggested test method, the simulation and actural experiment carried out emulation for a 2.2kW induction motor.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1999년도 가을 학술발표회 논문집
• /
• pp.67-74
• /
• 1999

Self-Boring Pressuremeter Test(SBPT) is known to be the most effective in-situ test method which can reliably determine consolidation characteristics as well as deformation modules and untrained shear strength. In order to derive the coefficient of consolidation using SBPT results it is necessary to obtain the dissipation behavior from the pore pressure change with time during constant radial strain(generally 10%) and to derive the reliable time factor(Τ) from the analytical method which considers the real in-situ conditions. As previous studies on time factor are based on the assumptions of plane strain condition that the membrane of SBP is infinite, of untrained condition during the expansion of the probe and of elastic soil behavior during consolidation, these analyses can't consider the real boundary conditions and the real soil behaviour. In this study, consolidation analysis similar to real in-situ conditions including test procedure is conducted using finite element program which employs MCC model and Biot theory. Time factor considering the effects of finite membrane length, the total pressure change during consolidation and partial drainage is proposed and compared with previous results.

• Nuclear Engineering and Technology
• /
• 제54권12호
• /
• pp.4481-4490
• /
• 2022

In this study, a new rupture disk corrosion test (RDCT) method was developed for real-time detection of stress corrosion cracking (SCC) initiation of Alloy 600 in a primary water environment of pressurized water reactors. In the RDCT method, one side of a disk specimen was exposed to a simulated primary water at high temperature and pressure while the other side was maintained at ambient pressure, inducing a dome-shaped deformation and tensile stress on the specimen. When SCC occurs in the primary water environment, it leads to the specimen rupture or water leakage through the specimen, which can be detected in real-time using a pressure gauge. The tensile stress applied to the disk specimen was calculated using a finite element analysis. The tensile stress was calculated to increase as the specimen thickness decreased. The SCC initiation time of the specimen was evaluated by the RDCT method, from which result it was found that the crack initiation time decreased with the decrease of specimen thickness owing to the increase of applied stress. After the SCC initiation test, many cracks were observed on the specimen surface in an intergranular fracture mode, which is a typical characteristic of SCC in the primary water environment.

• 한국입자에어로졸학회지
• /
• 제10권1호
• /
• pp.1-8
• /
• 2014

In this study, we have developed a real-time monitoring device for measuring $PM_{10/2.5/1}$ of ambient aerosol particles. The real-time PM (Particulate Matter) monitor was based on the light scattering method and had 16 channels in particle size. The laboratory and field tests were carried out to evaluate the performance of the PM monitor developed. Arizona Road Dust particles ranging from diameter of 0.1 to $20{\mu}m$ were generated as test particles in the laboratory test. The field test was carried out at the Seoul Meteorological Observatory. We can obtain the particle size and number concentration (particle size distribution) only from the real-time PM monitor developed. Therefore, the average density of aerosol particles was used to obtain the PM data from the particle size distribution. The $PM_{10/2.5/1}$ results of the PM monitor were compared with the data of the Grimm Dust Monitor (Model 1.108) and a beta ray gauge (Thermo Fisher Scientific). As a result, it was shown that the $PM_{10/2.5/1}$ results obtained by the real-time PM monitor agreed well with the data of the reference devices, and overall, the real-time PM monitor could be used as a PM monitoring device for real-time monitoring of the ambient particles.

• Smart Structures and Systems
• /
• 제31권6호
• /
• pp.601-619
• /
• 2023

In this study, the accuracy of a real-time hybrid test (RTHT) employed for a performance test of a tuned mass damper (TMD) on an offshore wind turbine (OWT) with a complicated jacket-type supporting structure is quantified and evaluated by comparing the RTHT results with the experimental data obtained from a shaking table test (STT), in which a 1/25-scale model for a typical 5-MW OWT controlled by a TMD was tested. In the RTHT, the jacket-type OWT structure was modelled using both multiple-DOF (MDOF) and single-DOF (SDOF) numerical models. When compared with the STT test data, the test results of the RTHT show that while the SDOF model, which requires less control computational time, is able to well predict the peak responses of the nacelle and TMD only, the MDOF model is able to effectively predict both the peak and over-all time-history responses at multiple critical locations of an OWT structure. This also indicates that, depending on the type of structural responses considered, an RTHT with either an SDOF or a MDOF model may be a promising alternative to the STT to assess the effectiveness of a TMD for seismic mitigation in an OWT context.