• Steel and Composite Structures
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• 제27권1호
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• pp.13-25
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• 2018

The main objective of this study is to develop a dual approach for geometrically nonlinear finite element analysis of plane truss structures. The geometric nonlinearity is considered using the Total Lagrangian formulation. The nonlinear solution is obtained by introducing and minimizing an objective function subjected to displacement-type constraints. The proposed method can fully trace the whole equilibrium path of geometrically nonlinear plane truss structures not only before the limit point but also after it. No stiffness matrix is used in the main approach and the solution is acquired only based on the direct classical stress-strain formulations. As a result, produced errors caused by linearization and approximation of the main equilibrium equation will be eliminated. The suggested algorithm can predict both pre- and post-buckling behavior of the steel plane truss structures as well as any arbitrary point of equilibrium path. In addition, an equilibrium path with multiple limit points and snap-back phenomenon can be followed in this approach. To demonstrate the accuracy, efficiency and robustness of the proposed procedure, numerical results of the suggested approach are compared with theoretical solution, modified arc-length method, and those of reported in the literature.

• 한국소음진동공학회논문집
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• 제26권7호
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• pp.774-780
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• 2016

In this paper noise source and transfer path of tactical vehicle are analyzed with partial coherence function and spectrum analysis. Engine, transmission, structure panel and aerodynamic are main source of cabin noise. To reduce cabin noise, identifying transfer path of sources and analyzing their contribution is important. With modeling of transfer path and partial coherence function, transfer path and principal noise source can be identified. Engine/transmission and structural resonance are principal source of low frequency noise and by adding stiffener and sound absorbing material, resonance of vibration and inflow air problem can be solved.

• 한국소음진동공학회논문집
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• 제17권8호
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• pp.741-746
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• 2007

In this study, transfer path identification and output estimation are simulated by multi-dimension spectral analysis method (MDSA). Multi -input/single-output system give expression the vehicle suspension which each inputs are correlated reciprocally. In case of correlating with inputs, the system needs separating the each input signal by MDSA. Main simulations are about finding effective input by coherent output spectrum and selecting optimal input's number by multiple coherence function. Also, by shielding transfer path of each input, transfer path characteristic is identified in terms of overall integrated contribution level.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.168-175
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• 2001

Reduction of structure-borne noise of the compartment in a car is an important task in automotive engineering. Transfer path analysis using vibroacoustic reciprocity technique or multiple path decomposition method has generally been used for structure-borne noise path analysis. These methods are useful in solving particular problem but do net quantify the effectiveness of vibration isolation of each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow has been used for a simple isolation system or a laboratory based isolation system. It is often difficult to apply the vibrational power flow technique to the complex isolation system like a car. In this paper, a simple equation is derived for calculation of the vibrational power flow of an isolation system with multiple isolators such as a car. It is successfully applied to not only quantifying the relative contributions of eighteen isolators but also reducing structure-borne noise of a passenger car. According to the results, the main contributor of eighteen isolators is the rear roll mount of an engine. The reduced structure-borne noise level is about 5dBA.

• 해양환경안전학회지
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• 제23권6호
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• pp.661-668
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• 2017

본 연구의 목적은 혼산 화물의 폭발사고에 대한 화학반응 경로를 분석하는데 있다. 분석에는 사건-가지분석기법을 적용한 구조적인 시나리오를 이용하였다. 구조적인 시나리오는 재결서에 기록된 혼산 화물 사고의 내용에서 다양한 화학반응 경로를 추정하여 구축하였다. 분석에는 화학 이론에 의거한 정성적 분석과 화학 반응식을 이용한 정량적 분석 및 설문조사를 통한 확률적 분석 등 세 가지 방법을 혼합 적용하였다. 분석결과, 사고 발생의 주요 경로는 진한 황산과 물이 반응하여 폭발하는 경로, 혼산과 금속이 반응하여 폭발하는 경로, 특수한 물질과 합성하여 폭발하는 경로 등 세 가지로 나타났다. 이 결과는 재결서에 기록된 경로와 유사함을 알았고, 이를 통해서 본 연구에서 제안한 화학물질의 경로분석 기법이 타당함을 알았다. 본 연구에서 제안한 방법은 다양한 화학물질 사고의 화학반응 경로 추정에 적용 가능할 것으로 기대된다.

• 한국비블리아학회지
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• 제30권2호
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• pp.189-209
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• 2019

주경로 분석(Main Path Analysis, MPA)은 문헌의 인용정보를 기반으로 지식이 전달되는데 기여한 핵심 문헌을 추출하는 텍스트마이닝 기법 중 하나이다. 본 연구는 1990년부터 2018년까지 국내외에서 발행된 장소성 관련 논문의 인용정보와 초록을 토대로 주경로 분석과 단어동시출현빈도 연관어 네트워크 분석을 적용하여 연구동향을 파악하였다. 1990년부터 2018년까지 수집된 문헌을 5년씩 기간 구분하여 (마지막 기간은 3년) 각 기간 별로 국내외에서 장소성 관련 연구가 전반적으로 어떻게 진행되었는지 비교 분석하여 제시하였다. 주경로 분석 결과, 1990년부터 해외의 장소성 관련 연구는 개인 정체성, 공공 토지 관리, 환경 교육, 도시 개발 분야 순으로 진행되어 온 것으로 나타났다. 단어동시출현을 기반으로 한 연관어 네트워크를 통해서는 국내의 경우 도시 개발, 문화, 문학, 역사 등 다양한 차원에서 장소성이 논의되는 격변기를 겪는 것으로 해석할 수 있었다. 반면 국외에서는 건강, 정체성, 경관, 도시 개발 관련 논의가 90년대부터 꾸준히 이루어지고 있는 것으로 파악되었다. 본 연구는 장소성 연구동향을 기존의 특정 영역에 장소성 개념을 적용하여 분석하는 미시적 관점의 분석이 아닌 다양한 텍스트마이닝 기법을 적용하여 장소성을 주제로 삼고 있는 논문의 전반적인 흐름을 파악하는 통시적 접근의 방법을 제시하였다는 점에서 시사점을 지닌다.

• 한국빅데이터학회지
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• 제4권1호
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• pp.99-118
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• 2019

본 연구는 소셜 미디어 참여 관련 연구 베타분석을 위해 네트워크 분석과 클러스터링 기법을 활용하였다. 주경로 분석 결과 37개의 주요 연구가 추출되었고 커뮤니티 관련 네트워크와 뉴 미디어 관련 네트워크 두 가지로 구분되었다. 연결망 분석과 클러스터링 결과 네가지 클러스터가 형성되었다. 본 연구는 학술 데이터를 활용해 연구 동향을 거시적으로 파악하며 그 방법론으로 네트워크 분석과 기계학습을 활용하였다는 학술적 의의를 가진다.

• 한국실내디자인학회논문집
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• 제16권6호
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• pp.144-151
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• 2007

The idea of shopping is changed from a purchase of merchandise to an experience of pleasure. This study is a space composition analysis for the introduction of theme in multi-plex shopping center design to reflect variable consumer trend and company marketing strategy, The study progressed through theoretical consideration and substance analysis about the shopping centers which had been designed by Jerd Partnership In Japan since 2000. The following is result. The path is a sole main street that is made of curve form, parallel and vertical circulating rout and movement of human being. It leads continuity. The node and landmarks have a circular court with typifier as powerful center, character of transition space and event for experience. It makes locational quality. The districts are composed of retail shops, restaurants and culture facilities and the edge is represented by closed vertical wall and parapet. It induces a domain. The characteristic of Jerde shopping center is an experience of theme environment through the path as betweenness with a story based on a main theme. It is mostly related nature or exotic element and is obviously represented at path and node. The node takes a round shape and bring about event as a court. The application of theme to the shopping center by Jerde has a significant meaning for place marketing.

• 대한수학회논문집
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• 제32권3호
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• pp.765-778
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• 2017

Finding an initial feasible solution on the central path is the main difficulty of feasible interior-point methods. Although, some algorithms have been suggested to remedy this difficulty, many practical implementations often do not use perfectly centered starting points. Therefore, it is worth to analyze the case that the starting point is not exactly on the central path. In this paper, we propose a weighted-path following interior-point algorithm for solving the Cartesian $P_{\ast}({\kappa})$-linear complementarity problems (LCPs) over symmetric cones. The convergence analysis of the algorithm is shown and it is proved that the algorithm terminates after at most $O\((1+4{\kappa}){\sqrt{r}}{\log}{\frac{x^0{\diamond}s^0}{\varepsilon}}\)$ iterations.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.202-210
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• 2019

The obstacles modeling is a fundamental and significant issue for path planning and automatic navigation of Unmanned Surface Vehicle (USV). In this study, we propose a novel obstacles modeling method based on high resolution satellite images. It involves two main steps: extraction of obstacle features and construction of convex hulls. To extract the obstacle features, a series of operations such as sea-land segmentation, obstacles details enhancement, and morphological transformations are applied. Furthermore, an efficient algorithm is proposed to mask the obstacles into convex hulls, which mainly includes the cluster analysis of obstacles area and the determination rules of edge points. Experimental results demonstrate that the models achieved by the proposed method and the manual have high similarity. As an application, the model is used to find the optimal path for USV. The study shows that the obstacles modeling method is feasible, and it can be applied to USV path planning.