• 제목/요약/키워드: model investigation

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한국의 해양사고 조사모델의 개선에 관한 연구 (A Study on the Improvement of Marine Accidents Investigation Model in Korea)

  • 나송진;김상수;박진수;정재용
    • 한국항해항만학회지
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    • 제27권4호
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    • pp.367-373
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    • 2003
  • 우리나라의 해양안전심판원은 지난 40년동안 많은 업적을 남겼지만, 아직도 해양사고의 조사에 대한 법과 제도 및 매뉴얼 등의 내용 면에서 미흡한 점이 있다. 조사매뉴얼은 국제해사기구의 해양사고조사지침 등의 국제규정과 기준을 수용하지 못하고 심판지침과 함께 작성되어 있을 뿐만아니라 그 구성과 내용 및 조사기법 등이 매우 부실하다. 그리고, 조사제도는 심판원이 독립성을 가지지 못하고 재발방지를 위한 권고기능이 크게 위축되어 있는 실정이다. 또한, 해양사고의 원인판단지침이 없어 조사관이 항법을 적용하는데 있어 혼동하거나 오류를 범하는 경우가 종종 발생하고 있고 초임 조사관 등의 사고원인판단의 기준으로 활용할 수 있는 교재도 없다. 이 연구에서는 영국, 미국, 네덜란드 및 일본의 조사매뉴얼과 조사제도를 비교ㆍ분석하여 개선안을 제안하고, 사고 종류별 질문조사기법을 제안한다.

고압에서의 액적의 증발현상에 관한 연구 (Investigation of Droplet Vaporizatio Phenomena in High Pressure Environments)

  • 이현창;백승욱
    • 한국연소학회지
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    • 제13권3호
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    • pp.17-23
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    • 2008
  • The spray combustion and spray cooling depends on droplet evaporation. So, evaporation model for spray has been requested and lots of investigation has been done and various reliable models have been developed also for last few decades. In the present study, One dimensional quasi-steady spherically symmetric droplet evaporation model for micro-gravity is developed. The gas phase was assumed as steady state and the thermophysical properties are calculated as a function of temperature, pressure and composition and the properties used in the model was validated by NIST web data and overall evaporation history results was compared with experimental results by Nomura and Qasim and gave satisfactory agreements. Through this model, diverse phenomenon was investigated, especially regarding the effects of ambient pressure and temperature. The effects of pressure for the droplet evaporation time were studied. The high pressure increased the droplet surface temperature and made effect on the evaporation time depend on atmospheric temperature. The role of the ambient temperature was investigated and explained. The basic investigation for the evaporation process according to variation of droplet diameter and surface temperature were also investigated and the well-known phenomena, like D-square-law, were reported, too.

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Reserve capacity of fatigue damaged internally ring stiffened tubular joints

  • Thandavamoorthy, T.S.
    • Steel and Composite Structures
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    • 제4권2호
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    • pp.149-167
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    • 2004
  • Offshore platforms have to serve in harsh environments and hence are likely to be damaged due to wave induced fatigue and environmental corrosion. Welded tubular joints in offshore platforms are most vulnerable to fatigue damage. Such damages endanger the integrity of the structure. Therefore it is all the more essential to assess the capacity of damaged structure from the point of view of its safety. Eight internally ring stiffened fatigue damaged tubular joints with nominal chord and brace diameter of 324 mm and 219 mm respectively and thickness 12 mm and 8 mm respectively were tested under axial brace compression loading to evaluate the reserve capacity of the joints. These joints had earlier been tested under fatigue loading under corrosive environments of synthetic sea water and hence they have been cracked. The extent of the damage varied from 35 to 50 per cent. One stiffened joint was also tested under axial brace tension loading. The residual strength of fatigue damaged stiffened joint tested under tension loading was observed to be less than one fourth of that tested under compression loading. It was observed in this experimental investigation that in the damaged condition, the joints possessed an in-built load-transfer mechanism. A bi-linear stress-strain model was developed in this investigation to predict the reserve capacity of the joint. This model considered the strain hardening effect. Close agreement was observed between the experimental and predicted results. The paper presents in detail the experimental investigation and the development of the analytical model to predict the reserve capacity of internally ring stiffened joints.

주파수응답함수를 이용한 감쇠가 있는 유한요소모형의 개선 (Updating of a Finite Element Model with a Damping Effect Using Frequency Response Functions)

  • 이건명;이형석;이한희
    • 대한기계학회논문집A
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    • 제26권5호
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    • pp.872-880
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    • 2002
  • The finite element analysis is frequently used to predict dynamic responses of complex structures. Since the predicted responses often differ from experimentally measured ones, updating of the finite element models is performed to make the finite element results agree with the measured ones. Among several model updating methods, one is to use FRF(frequency response function) data without a modal analysis. This paper investigates characteristics of the model updating method in order to improve the method. The investigation is focused on how to obtain FRFs for unmeasured rotational displacements and how to consider damping. For the investigation simulated data and experimental data for a cantilever beam are used.

산악지역 내 LNAPL 오염의 개념모델 정립을 위한 사례연구

  • 강우재;공준;전진오;이상봉;황종식;배우근
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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    • pp.85-88
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    • 2001
  • Since mountainous area has access restrictions for field work, assessors need to establish a conceptual model of the contamination prior to the field investigation. In this study we established a conceptual model of the contamination based on site inspection and geological survey, followed by the field investigation for the petroleum spill site. In the conceptual model, we estimated that tile contamination should have spread by groundwater and topographical characteristics within the top soil layer. The spread of contamination through rock was not considered in the conceptual model due to impermeable characteristics of metasyenite. The contaminated environmental media of the petroleum spill site include soil and groundwater. According to the analysis result of the contamination, the volume of contaminated soil is estimated approximately 4, 150 cubic meters (7, 055 ton) with most contaminants existing along the groundwater flow within top soil layer.

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열박음 공정이 케이스의 온도분포 및 변형에 미치는 영향(II) - 변형 계측 및 변형 해석 모델 정립 - (A Study on the Temperature Distribution and Deformation of Case in Shrinkage Fit Process(II) - Deformation Measurement and Deformation Analysis Model -)

  • 장경복;정진우;강성수;최규원;박찬우;조상명
    • Journal of Welding and Joining
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    • 제19권5호
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    • pp.492-498
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    • 2001
  • In the previous study, temperature monitoring of case about shrinkage fit process was performed and heat transfer model was developed in detail by feedback and tuning among monitoring result, process investigation, and analysis result. The gap element in contact between case and core was effectively used in analysis model. In present study, following things are performed to solve deformation of case due to shrinkage fit process on the basis of previous result. Above all, mechanical material properties of case are measured by case specimen for deformation analysis considering weldment of case. Deformation of case before and after shrinkage fit process is measured, too. Three dimensional deformation model is developed by the comparison and inspection between these experimental data and analysis results. Deformation analysis is simulated with the result of heat transfer analysis, in other words, non-coupled analysis is used. Finally the countermeasure for deformation is brought up through those.

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From Opposition to Cooperation: Semantic Change of with

  • Rhee, Seongha
    • 한국영어학회지:영어학
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    • 제4권2호
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    • pp.151-174
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    • 2004
  • A historical investigation reveals that English preposition with underwent a change from OPPOSITION to ASSOCIATION and further to ACCOMPANIMENT, where the first stage shows peculiarity in that the two concepts involved comprise an unusual set to form an extensional chain. Intrigued by this oddity, this paper aims to investigate the semantic structure of English preposition with from a grammaticalization perspective. We review mechanisms and models of semantic change and evaluate their adequacy with the semantic structure and change shown by with. Drawing upon the observed fact that with underwent the apparent antonymic semantic change, it is argued that such semantic change mechanisms as metaphor, metonymy, subjectification, and generalization have difficulties explaining the change, and that only the Frame-of-Focus Variation can effectively account for this peculiar change type. In terms of semantic change models, we argue that the Bleaching Model cannot effectively provide an explanation; that the Loss and Gain Model has problems in explaining the motivation of change directions; that the Metonymic-Metaphoric Model cannot be assessed at the current level of investigation; and that the Overlap Model and the Prototype Extension Model excellently account for the macro-level changes.

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Fraud Investigation, Internal Audit Quality and Organizational Performance: Empirical Evidence from Thai Listed Companies

  • JANNOPAT, Saithip;PHORNLAPHATRACHAKORN, Kornchai
    • The Journal of Asian Finance, Economics and Business
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    • 제9권1호
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    • pp.311-324
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    • 2022
  • The objective of this study is to examine the influence of fraud investigation on organizational performance of Thai listed companies through mediating effects of internal audit quality, accounting information transparency and financial effectiveness, and moderating effect of corporate governance. In this study, 333 Thai listed companies are the samples of the study. Both the structural equation model and multiple regression analysis are used to examine the research relationships. The results of this study show that fraud investigation has a significant influence on internal audit quality, accounting information transparency, and financial effectiveness. Internal audit quality significantly influences accounting information transparency, financial effectiveness, and organizational performance while financial effectiveness significantly influences organizational performance. Next, both internal audit quality and financial effectiveness potentially mediate the fraud investigation-organizational performance relationships. In addition, corporate governance critically moderates the fraud investigation-internal audit quality relationships and the fraud investigation-financial effectiveness relationships. In summary, fraud investigation functions as an important valuable technique of internal audit practices. As a result, businesses must build and implement a systematic fraud investigation procedure to generate and improve beneficial outcomes in the short, medium, and long term.

국제결혼한 농촌남성의 에이전시에 대한 생애사적 '사례이해' (A Biographical 'Caseunderstanding' on the Agency of Men in international Marriage in Rural Areas)

  • 양영자
    • 한국사회복지학
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    • 제63권1호
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    • pp.317-342
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    • 2011
  • 본 연구의 목적은 국제결혼한 농촌남성들의 에이전시를 생애사적 맥락에서 재구성하는 데에 있다. 이를 위해 생애사적-내러티브 인터뷰 8개를 실시하였고, 인터뷰자료는 Sch$\ddot{u}$tze의 생애사적-내러티브 인터뷰 분석과 Rosenthal의 내러티브식-생애사 인터뷰 분석 방법을 응용하여 분석하였다. 그 결과, 다중적 소외자로 객체화되고 있는 외부자적 관점과는 달리, 에이전시를 작동시키며 살아가고 있는 주체로 재현되고 있었는데, 주 생활영역인 직업생활에서는 주변부에 자리한 직업적 위치에도 불구하고 자기주도적인 직업생활을 하도록 추동하는 에이전시가, 가정생활에서는 '아래로부터의 다문화주의'를 실현하는 초국가적 가정의 주체로 위치시키는 에이전시가, 그리고 학교생활에서는 탈획일화된 학교의 주체로 자리매김하도록 추동하는 에이전시가 작동되고 있었고 또 현재도 작동되고 있음을 포착하였다. 이러한 연구결과에 근거해 국제결혼한 농촌남성들에 대한 이해가 전제된 사회복지실천을 하는 데에 시사하는 함의를 제시하였다.

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