• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.286-289
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• 1997

In the design of structure the forces acting on the structure are important parameter for noise and vibration control. However, in the complex structure, the forces at the injection pomt on the structure cannot be measured directly. Thus it is necessary to find out indirect force evaluation method. In thls paper forces have been measured with in-situ vibration responses and system information. Three existing techniques of indirect force measurement, viz. direct inverse, principal component analysis and regularization have been compared. It has been shown that multi-vibration responses are essential for the precise estimation of the forces. To satisfy those cond~tions, Rotary compressor is adopted as test sample, because it is very difficult to measurc the injection forces from internal excitat~on to shell. It has also been obtained that relatively higher force IS transmitted through three welding paths to the compressor shell. It shows a good agreement between direct and indirect force evaluation wlth curvature shell and plate and is investigated the possibility of force evaluation of rotary compressor as a complex structure.

• 대한기계학회논문집
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• 제9권2호
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• pp.190-201
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• 1985

본 논문에서는 측정된 공작기계의 동적성능은 절삭조건과 공작기계의 동적 컴 플라이언스의 복합적인 함수이므로 공작기계의 동적 성능을 정확히 평가하고 설계.개 선을 용이하게 하기 위하여는 직접절삭시험 중 가진 시험을 동시에 수행하는 방법이 필요하다. 본 연구에서는 선반의 외경 선삭가공중의 동적성능을 직접절삭시험과 가 진 직접절삭법을 통하여 평가하고자 한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.631-638
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• 2006

This paper considers the nonlinear direct spectrum method to estimate seismic performance of mixed building structures without iterative computations, given dynamic property $T_1$ from stiffness skeleton curve and nonlinear pseudo acceleration $A_{1y}$ and/or ductility ratio $\mu$ from response spectrum. Nonlinear response history analysis has been performed and analysed with various earthquakes for evaluation of correctness and confidence of nonlinear direct spectrum method.

• 한국안전학회지
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• 제16권4호
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• pp.74-81
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• 2001

A direct numerical simulation (DNS) was applied to nonpremixed counter-flow diffusion flames between oxidizer and fuel ducts. The objective of this study is to evaluate the numerical method for simulation of axisymmetric counterflow diffusion flames. Effects of computational domain size and grid size were scrutinized, and then the method was applied to air-methane diffusion flames. The results at zero gravity conditions were in good agreement with those obtained by the one-dimension flame code OPPDIF. It was confirmed thai the numerical method is applicable to the diffusion flames at the normal gravity conditions since the results clearly showed the effects of buoyancy and velocity ratio.

• 한국정보통신학회논문지
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• 제3권4호
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• pp.839-847
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• 1999

본 논문에서는 MC 시뮬레이션 기법과 QA 시뮬레이션 기법을 이용하여 인접채널간섭, 동위상간섭, 가우시안 잡음이 존재하는 직접위성방송 채널을 성능 평가하였다. 시뮬레이션을 하기 위한 시스템 파라미터들은 현재 무궁화호 위성에서 사용하고 있는 파라미터 및 링크 설계를 기초로 하여 설정하였으며, 두 가지 기법 모두 성능이 수학적 이론 성능에 근접함을 알 수 있었다.

• 한국통신학회논문지
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• 제17권8호
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• pp.846-855
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• 1992

In this paper, the decrease multipoint search method and Its learning algorithm for optimum value computatlon method of object function Is proposed. Using this method, the number of evaluation point according to searching time can t)e reduced multipoint of the direct search method by applying the unlivarlate method. And the learning algorithm can reprat the same search method in a new established boundary by using the searched result. In order to Investigate the efficience of algorithm, this method this method is applied to Rosenbrock and Powell, Colvelle function that are Impossible or uncertain in traditional direct search method. And the result of application, the optimum value searching oil every function Is successful. Especially, the algorithm is certified as a good calculation method for producing global(absolute) optimum value.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2004년도 추계학술대회 논문집
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• pp.382-384
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• 2004

• Industrial Engineering and Management Systems
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• 제14권1호
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• pp.58-72
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• 2015

A primary concern of national R&D plans is to encourage technological development in private firms and research institutes. For effective R&D planning and program support, it is necessary to assess technological impacts that may exist both directly and indirectly among technology areas within the whole technology system; however, previous studies analyze only direct impacts among technologies, failing to capture both direct and indirect impacts. Therefore, this study proposes an approach based on decision-making trial and evaluation laboratory (DEMATEL) to identifying specific characteristics of technology areas, such as technological impact and degree of cause or effect (DCE). The method employs patent co-classification analysis to construct a technological knowledge flow matrix. Next, to capture both direct and indirect effects among technology areas, it incorporates the modified DEMATEL process into patent analysis. The method helps analysts assess the technological impact and DCE of technology areas, and observe their evolving trajectories over time, thereby identifying relevant technological implications. This study presents a case study using Korean patents registered during 2003-2012. We expect our analysis results to be helpful input for R&D planning, as well as the suggested approach to be incorporated into processes for formulating national R&D plans.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.356-363
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• 2004

In this research, the shear behavior of four different interfaces consisting of 4 types of geosynthetics was examined, and both static and dynamic tests for the geosynthetic interface were conducted. The monotonic shear experiments were performed by using an inclined board apparatus and large direct shear device. The interface shear strength obtained from the inclined board tests were compared with those calculated from large direct shear tests. The comparison results indicated that direct shear tests are likely to overestimate the shear strength in low normal stress range where direct shear tests were not performed. Curved failure envelopes were also obtained for interface cases where two static shear tests were conducted. By comparing the friction angles measured from three tests, i.e. direct shear, inclined board, and shaking table tests, it was found that the friction angle might be different depending on the test method and normal stresses applied in this research. Therefore, it was concluded that the testing method should be determined carefully by considering the type of loads and the normal stress expected in the field.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.129-139
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• 2003

The response displacement method is the most frequently used method for seismic design of buried structures. This method is pseudo-static method, and the evaluations of velocity response spectrum of seismic base and response displacement of surrounding soil are the most important steps. In this study, the evaluation of velocity response spectrum of seismic base according to the Korean seismic design guide and the simple method of calculating the response displacement were studied. It was found that velocity response spectrum of seismic base can be estimated by direct integrating the ground-surface acceleration response spectrum of soil type $S_{A}$, and the evaluation of the response displacement using double cosine method assuming two layers of soil profile shows the advantages in the seismic design.n.