• 한국농공학회논문집
• /
• 제49권6호
• /
• pp.37-46
• /
• 2007

In designing the structure, the stress path is the basic data. But the stress path is not standardized to analysis the structure. So the one-dimensional frame element structure model with the triangle irregular network is used to solve the problem. And the refined evolutionary structural optimization(RESO) used in structural topology optimization is applied to this study. Through this process, the search method of the stress path is advanced and the burden of the calculation. is reduced.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
• /
• pp.270-277
• /
• 2004

In this paper, path-independent values of the J-integral in the fininte element context for arbitrary two-dimensional and three-dimensional crack configurations in welds are presented. For the fracture mechanics analysis of cracks in welds, residual stress analysis and fracture analysis must be performed simultaneously. In the analysis of cracked bodies containing residual stress, the usual domain integral formulation results in path-dependent values of the J-integral. This paper discusses modifications of the conventional J-integral that yield path independence in the presence of residual stress generated by welding. The residual stress problem is treated as an initial strain problem and the J-integral modified for this class of problem is used. And a finite element program which can evaluate the J-integral for cracks in two-dimensional and three-dimensional residual stress bearing bodies is developed using the modified J-integral definition. The situation when residual stress only is present is examed as is the case when mechanical stresses are applied in conjunction with a residual stress field.

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

• KIEAE Journal
• /
• 제5권1호
• /
• pp.35-42
• /
• 2005

The primary concerns of recreation plan are to provide visitors with quality of recreational experience and to protect of recreation resources. The quality of recreational experience is often defined in terms of social carrying capacity. The carrying capacity is revealed as perceived crowding. In this respects, measuring perceived crowding is useful tool of social carrying capacity determination. This study is to test the structural equation model that includes variables affecting perceived crowding. Through an on-site questionnaire survey, 467 visitors on Naejangsan national park were collected. The results of the study are follows. The encounter level on facility area is higher evaluated as crowding factor than other area in the park. It can be concluded that visitor perceived crowding when facility area situates high density use level rather than other areas expose high density use level. In the path analysis, the input variables(attitude, experience, encounter level) on the structural equation model affect significantly on perceived crowding. Especially, the attitude on the park management polocy is the most affecting factor on perceived crowding.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.891-897
• /
• 2006

The volume control method which utilize a pressure node added into a finite shell element can overcome the drawbacks of conventional load control method and displacement control method. In this study, an improved volume control method is introduced for effective analysis of path-dependant behaviors of RC structures subjected to cyclic loading. RC shell structures including RC hollow columns are anlayized by discretizing the structures with layered shell elements and by applying in-plane two dimensional constitutive equations for concrete layers and reinforcement layers of the shell elements. The so-called path dependant volume control method is verified by comparing analysis results with other data including experimental results.

• 대한간호학회지
• /
• 제34권2호
• /
• pp.333-343
• /
• 2004

Purpose: This study was designed to construct a structural model for symptom management of life of the patients with chronic fatigue. The hypothetical model was developed based on the literature review and Self-regulating Model. Method: Data were collected by questionnaires from 252 patients with chronic fatigue in the 8 community from December 2002 to April 2003 in Seoul. Data analysis was done with SAS for descriptive statistics and PC-LISREL Program for Covariance structural analysis. Result: The fit of the hypothetical model to the data was moderate, thus it was modified by excluding 4 path and including free parameters and 3 path to it The modified model with path showed a good fitness to the empirical data($x^2$=318.11, p=0.0, GFI=.98, AGFI=.98, NNFI=.95, RMSR=.03, RMSEA=.05). The symptoms of stress, self-efficacy, and present fatigue level were found to have significant direct effect on symptom management of the patients with chronic fatigue. The ways of coping, perceived stress, and fatigue symptom were found to have indirect effects on symptom management of the patients with chronic fatigue. Conclusion: The derived model is considered appropriate in explaining and predicting symptom management of the patients with chronic fatigue. Therefore, it can effectively be used as a reference model for further studies and suggested direction in nursing practice.

• 한국IT서비스학회지
• /
• 제14권2호
• /
• pp.15-31
• /
• 2015

Software piracy is widespread throughout the world. It has negative effects on the software industry and the intellectual property market. Despite various deterrent policies, the phenomenon has been getting severe. The current study investigated the antecedents of software piracy attitudes and intention. In order to identify factors and their relationship, a research model for illegal piracy behavior was developed and empirically examined through a path analysis using structural equation model. Also, this study employed a multiple group structural equation model to investigate differences in structural weights across PC software user group and smartphone application user group. It was revealed that perceived benefit, habit, social factor, self-efficacy had positive effect on attitude toward software piracy, whereas perceived risk had a decreasing influence on attitude. Relationships between piracy attitudes and intentions were significant as well. Furthermore, the cross validation between two groups showed the path coefficients of habit to attitude and attitude to intention were significantly different. Implications for research and practice are discussed.

• Structural Engineering and Mechanics
• /
• 제5권5호
• /
• pp.491-505
• /
• 1997

This paper deals with the formulation and solution of a wide class of structures, in the presence of both geometric and material nonlinearities, as a particular mathematical programming problem. We first present key ideas for the nonholonomic (path dependent) rate formulation for a suitably discretized structural model before we develop its computationally advantageous stepwise holonomic (path independent) counterpart. A feature of the final mathematical programming problem, known as a nonlinear complementarity problem, is that the governing relations exhibit symmetry as a result of the introduction of so-called nonlinear "residuals". One advantage of this form is that it facilitates application of a particular iterative algorithm, in essence a predictor-corrector method, for the solution process. As an illustrative example, we specifically consider the simplest case of plane trusses and detail in particular the general methodology for establishing the static-kinematic relations in a dual format. Extension to other skeletal structures is conceptually transparent. Some numerical examples are presented to illustrate applicability of the procedure.

• 한국기계가공학회지
• /
• 제17권1호
• /
• pp.69-75
• /
• 2018

This study aims to provide ways to achieve structural improvements of the internal flow path of the discharge plenum of a swash plate piston pump valve block vulnerable to cracks. This paper corresponds to Part I, which consists of a structural analysis of the valve block, identification of the stress distribution and stress raisers, and creation of a Simple Model of the valve block to review the optimal design. Structural analysis was performed by assigning the same conditions as those found in the valve block model, and the design was reviewed by examining three different design improvement plans for the internal flow path of the discharge plenum.

• International Journal of Automotive Technology
• /
• 제8권5호
• /
• pp.605-614
• /
• 2007

This paper presents the research results for the reduction of a gear whine noise based on experimental and analytic methods. The test vehicle has a whine noise problem at the passenger seats in a sport utility vehicle. To identify the transfer path of the interior noise due to the axle system, a vibration path analysis, modal analysis and operational deflection shape analysis are systematically employed. By using these various methods, it has been found that the interior noise generated by the axle system was airborne noise. To reduce and predict the whine generated by the axle system, structural modifications for the axle system are performed by using FEM and BEM techniques. The structural modification of the axle cover is suggested for the reduction of whine noise.