• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2002년도 학술대회지
• /
• pp.225-228
• /
• 2002

Supersonic jet impingement on a flat plate has been investigated to show the flow physics for different jet heights and to demonstrate the adequacy of the characteristics-based flux-difference Wavier-Stokes code Current study also compares the steady-state solutions obtained with variable CFL number for different grid spacing with the time-accurate unsteady solutions using the inner iterations, displaying a good agreement between the two sets of numerical solutions. The unsteady nature of wall fluctuations due to bouncing of the plate shock is also uncovered for high pressure ratios. The methodology is then applied to a complex vertical launcher system where the jet plume hits the bottom wail, deflects into the plenum and eventually exits through the vertical uptake. Flow structures within vertical launcher system are captured and solutions are partially verified against the flight test data. Present jet impingement study thus shows the usefulness of CFD in designing a complex structure and predicting flow behavior within such a system.

• Communications for Statistical Applications and Methods
• /
• 제16권2호
• /
• pp.217-228
• /
• 2009

계층 전이가 가능한 다계층 대기행렬에 대한 빠른 시뮬레이션 방법을 제시하고 이를 이용하여 총 고객의 수가 적정 수준을 초과하는 과부하 발생 확률과 과부하 발생시 각 계층별 평균 고객의 수를 추정한다. 또한 이들 값들이 시스템의 총 로드나 계층별 로드에 따라 어떤 차이를 보이는지도 빠른 시뮬레이션을 통해 서로 비교한다.

• 한국디지털건축인테리어학회논문집
• /
• 제9권1호
• /
• pp.19-29
• /
• 2009

The architectural space is the involuntary place where man lives and experiences, and as a 3 dimensional space through the continuous experience with the concept of 4th dimension of time, it provides the observers with the dramatic space imagery These kinds of space experiences are experienced mentally and perceptively through the physical elements of inner and outer space of the architectural buildings, and this space imagery is created here by all the space composing elemensts of the building. These space experiences are caused by the changing processes of the space characteristics, and the observers perceive the changes in space characteristics. The present building is going with Eco-Architecture. When 2008 sees the building,,Eco-Architecture design which hits appears. There is a possibility of seeing 16 kind types from that place. And From here examined the spatiality which is expressed. These changing processes of inner and outer space, space versus space, and unit space, which are perceived by the observer. It's way to help in architectural design and wishes.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2015년도 제46회 하계학술대회
• /
• pp.276-277
• /
• 2015

As the effect of global warming continues, surge rates in Korea are also getting increased. Although there are devices to protect distribution line from the surge like lightning arrester, insulation of the lightning arrester can be destroyed if frequent surge occurs in distribution line. This paper assumed that the lightning surge hits the lightning arrester and make this device's insulation destroyed. This paper also simulated these processes utilizing EMTP/ATPDraw and verified voltage behavior when faults such as line to ground fault due to frequent lightning surge occur in lightning arrester.

• International Journal of Aeronautical and Space Sciences
• /
• 제12권3호
• /
• pp.260-265
• /
• 2011

In this paper, integrated missile guidance and control systems using time-delay control (TDC) are developed. The next generation missile requires that an interceptor hits the target, maneuvering with small miss-distances, and has lower weight to reduce costs. This is possible if the synergism existing between the guidance and control subsystems is exploited by the integrated controller. The TDC law is a robust control technique for nonlinear systems, and it has a very simple structure. The feature of TDC is to directly estimate the unknown dynamics and the unexpected disturbance using one-step time-delay. To investigate the performance of the integrated controller, numerical simulations are performed as the maneuver of the target. The results show that the integrated guidance and control system has a good performance.

• 한국비블리아학회지
• /
• 제10권1호
• /
• pp.163-174
• /
• 1999

본 연구의 목적은 디지털 도서관의 탐색 메카니즘의 구조, 디자인, 포맷, 용어 탐색결과 등에 대한 최종이용자의 만족도를 조사분석하여 새로운 대안을 제시하는 것이다. 이러한 연구목적을 달성하기 위하여. 표본으로 국가전자도서관 (http ://www. dlibrary. go. kr)의 탐색 메카니즘을 선택하고, 80명의 문헌정보학과 학생을 피험자로 선발한다. 그리고 최종이용자의 만족도를 설문지를 통하여 조사분석한다.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2008년도 춘계학술대회
• /
• pp.185-196
• /
• 2008

The objective of this study is to evaluate the mechanical behaviors and structural integrity of the weldment of high strength steel by using an acoustic emission (AE) techniques. Simple tension and AE tests were conducted against the 3 kind of welding test specimens. In order to analysis the effectiveness of weldability, joinability and structural integrity, we used K-means clustering method as a unsupervised learning pattern recognition algorithm for obtained multivariate AE main data sets, such as AE counts, energy, amplitude, hits, risetime, duration, counts to peak and rms signals. Through the experimental results, the effectiveness of the proposed method is discussed.

• 대한안전경영과학회지
• /
• 제10권4호
• /
• pp.127-134
• /
• 2008

The objective of this study is to evaluate the mechanical behaviors and structural integrity of the weldment of high strength steel by using an acoustic emission (AE) techniques. Monotonic simple tension and AE tests were conducted against the 3 kinds of welded specimen. In order to analysis the effectiveness of weldability, joinability and structural integrity, we used K-means clustering method as a unsupervised learning pattern recognition algorithm for obtained multi-variate AE main data sets, such as AE counts, energy, amplitude, hits, risetime, duration, counts to peak and rms signals. Through the experimental results, the effectiveness of the proposed method is discussed.

• 한국군사과학기술학회지
• /
• 제7권2호
• /
• pp.118-125
• /
• 2004

In anti-ship missile, the seeker and guidance control units are located in front of warhead. When the missile hits target, these structures play an important role to warhead structure like a shock absorber Because the shock waves are attenuated, the survival probability of warhead increases which guarantees the explosive train. In this thesis the role of frontal sections is studies. The theoretical analysis and numerical analyses using LS-DYNA code are performed. To prove the effect of shock absorber, the penetration test using subscale prototype warhead are executed.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2002년도 춘계학술발표논문집 (상)
• /
• pp.47-50
• /
• 2002

단백질 모티프(motif)란 유사한 기능을 가진 여러 단백질 서열에서 공통적으로 발견되는 패턴으로서 단백질의 기능을 예측하는 단서로 활용된다. 현재 Prosite, Pfam 등의 데이터베이스에서 정규식(regular expression), 가중치 행렬(weighted matrix). 은닉 마코프 모델(hidden Markov model)의 형태로 4천여종 이상의 모티프가 등록되어 있다. 하지만, 이러한 데이터베이스는 모티프와 단백질간의 일대일 관계만을 저장하고 있기 때문에, 모티프 간의 연관성을 파악하기는 어렵다. 본 논문에서는 모티프 간의 연관 관계를 연관 규칙의 형태로 발견하는 데이터 마이닝 기법을 제시한다. 아울러 HITS 데이터베이스로부터 입수한 단백질-모티프 데이터베이스에 본 기법을 적용함으로써 상당히 높은 연관성을 갖는 모티프 집단이 실제로 존재한다는 것을 밝힌다.