• 제목/요약/키워드: An empirical study

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An empirical formulation to predict maximum deformation of blast wall under explosion

  • Kim, Do Kyun;Ng, William Chin Kuan;Hwang, Oeju
    • Structural Engineering and Mechanics
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    • 제68권2호
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    • pp.237-245
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    • 2018
  • This study proposes an empirical formulation to predict the maximum deformation of offshore blast wall structure that is subjected to impact loading caused by hydrocarbon explosion. The blast wall model is assumed to be supported by a simply-supported boundary condition and corrugated panel is modelled. In total, 1,620 cases of LS-DYNA simulations were conducted to predict the maximum deformation of blast wall, and they were then used as input data for the development of the empirical formulation by regression analysis. Stainless steel was employed as materials and the strain rate effect was also taken into account. For the development of empirical formulation, a wide range of parametric studies were conducted by considering the main design parameters for corrugated panel, such as geometric properties (corrugation angle, breadth, height and thickness) and load profiles (peak pressure and time). In the case of the blast profile, idealised triangular shape is assumed. It is expected that the obtained empirical formulation will be useful for structural designers to predict maximum deformation of blast wall installed in offshore topside structures in the early design stage.

선원의 안전활동측면에서 본 선박의 안전관리 수준에 관한 실증연구 (An Empirical Study on the Level of Ship Safety Management in View of Seamen's Safety Activity)

  • 임종길
    • 한국항해학회지
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    • 제18권4호
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    • pp.83-118
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    • 1994
  • In this study, the writer embodies factors influencing on ship safety management by an empirical survey. In the empirical survey, the writer used a questionnaire. 1, 271 proper data was obtained from 4, 240 Korean seamen working in 152 domestic and 60 foreign merchant ships. Reliability was tested by Cronbach's Alpha and a conceptual validity by Factor Analysis. Hypotheses established in this study were tested by Correlation and Multiple Regression Analysis. Results of analysis are as follows: Firstly, three levels(i.e. planning, doing, and evaluation) of safety management and satisfaction level of shipboard life correlate significantly with level of ship safety management and between them(P<0.05) Secondly, satisfaction level of shipboard life, evaluation and planning levels of safety management influence significantly on level of ship safety management(P<0.05).

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Structure And Functions Of District Central Libraries In Tamil Nadu : An Empirical Study

  • Kumar, S.K. Asok;Babu, B. Ramesh
    • 정보관리연구
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    • 제38권4호
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    • pp.181-199
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    • 2007
  • This paper aims at projecting the structure and functions of District Central Libraries in Tamil Nadu based upon primary records collected from the Directorate of Public Libraries and survey of District Library officers who are the authorities of District Central Libraries. This paper reveals the State of Art the District Central Libraries and their functions. Based on outputs a number of suggestions have been provided. This paper represents an empirical research study.

Kano 품질속성 평가방법론들의 실증적 비교분석 (An Empirical Comparative Analysis Between Kano and Improved Kano Methods)

  • 윤재욱;이희영
    • 품질경영학회지
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    • 제37권4호
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    • pp.31-42
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    • 2009
  • Various studies have been undertaken in order to effectively understand customer requirements. Kano proposed a dualistic approach, physical fulfillment and customer satisfaction, to differentiate Attractive, Must-be, One-dimensional quality attributes. As there were a few limitations on the Kano's method, researchers have proposed improved methods. However, there have been few empirical evidences that the improved methods are superior to the original Kano's method for identifying relevant quality attributes. The objective of this study is to provide a comparative study on Kano and improved Kanomethods based on empirical analysis of quality attributes on University services. For the analysis of the questionnaire formats, the Kano's original 5 scale questionnaire is more effective than improved methods, direct and 3 scale questionnaire. For the analysis of evaluation methods, the original Kano and Timko's method using the evaluation table are more effective than quantifying methods, Domouchel and Lim's methods.

An ANP-Based Performance Model for ERP System's Implementation

  • Ko, Je-Suk;Park, Soon-Hak
    • Journal of the Korean Data and Information Science Society
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    • 제18권2호
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    • pp.401-409
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    • 2007
  • This paper addresses a performance evaluation model for ERP system's implementation using Analytic Network Process (ANP) technique. In this study, the performance variables are identified as the perspectives of cost, business process, systems operation, and change management, respectively. The empirical study also investigated factors that affect the performance variables to find out the causal relationship between them using the ANP approach. The data for the empirical analysis were collected from manufacturing companies that have implemented ERP systems. The research findings indicate the proposed model is powerful in proposing that the indirect relationship between influencing factors and managerial effectiveness, mediated by employee satisfaction, is an important one.

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An Empirical Study on Explosive Volatility Test with Possibly Nonstationary GARCH(1, 1) Models

  • Lee, Sangyeol;Noh, Jungsik
    • Communications for Statistical Applications and Methods
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    • 제20권3호
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    • pp.207-215
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    • 2013
  • In this paper, we implement an empirical study to test whether the time series of daily returns in stock and Won/USD exchange markets is strictly stationary or explosive. The results indicate that only a few series show nonstationary volatility when dramatic events erupted; in addition, this nonstationary behavior occurs more often in the Won/USD exchange market than in the stock market.

유통제조 기업의 해외 자회사 지식이전에서 기술특유성의 조절효과 (The Moderating Effects of Specificity of Technology in the Knowledge Transfer of Distributive Manufacturing MNEs)

  • 조연성
    • 유통과학연구
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    • 제14권9호
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    • pp.121-132
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    • 2016
  • Purpose - This study has the following objectives. First, it seeks to build an integrated model that can analyze the path through which headquarters, subsidiary competence, and knowledge transfer performance influence subsidiary performance. Second, it analyzes the influence of the specificity of technology as a moderating effect factor on knowledge transfer process. Third, it will conduct an empirical analysis on distributive manufacturing MNEs and suggests an implication for companies that actually need technological localization. The difference of this study are as follows. First, unlike the existing studies, this study can expand a theoretical discussion as it uses subsidiary performance as the dependent variable. Second, it sets the specificity of technology as a moderating effect factor, not an antecedent, and can draw a theoretical implication. Research design, data, and methodology - This study built a path analysis model to identify the influence of the disseminative capacity and absorptive capacity of distributive manufacturing MNEs on subsidiary performance. Based on the previous studies, it set 19 items as 5 latent variables, and established 6 hypotheses by including the moderating effect of the specificity of technology between them. The final 203 companies were selected as analysis samples through a survey questionnaire. For empirical analysis, the study used PLS (Partial Least Square) that is based on structural equation model. Results - The empirical analysis result demonstrated that both headquarters' disseminative capability and subsidiaries absorptive capacity had a positive influence on knowledge transfer performance. Knowledge transfer performance also had a positive influence on subsidiary performance. In the analysis of moderating effect, the specificity of technology acted as a significant moderating variable only between knowledge transfer performance and subsidiary performance; it did not show a statistically significant moderating effect among disseminative capability, absorptive capacity, and knowledge transfer performance. Conclusions - The empirical analysis results of this study demonstrate the importance of disseminative capability and absorptive capacity in knowledge transfer to subsidiaries from the distributive manufacturing MNEs in Korea. The analysis on the moderating effect indicates that the specificity of technology in Korean companies influences on the process of making achievement by using the transferred knowledge.

Efficacy of CFRP configurations for shear of RC beams: experimental and NLFE

  • Shuraim, Ahmed B.
    • Structural Engineering and Mechanics
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    • 제39권3호
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    • pp.361-382
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    • 2011
  • This paper presents the results of an investigation on shear strengthening of RC beams externally reinforced with CFRP composite. A total of six full-scale beams of four CFRP strengthened and two unstrengthened were tested in the absence of internal stirrups in the shear span. The strengthening configurations contained two styles: discrete uniformly spaced strips and customized wide strips over B-regions. The composite systems provided an increase in ultimate strength as compared to the unstrengthened beams. Among the three layouts that had the same area of CFRP, the highest contribution was provided by the customized layout that targeted the B-regions. A comparative study of the experimental results with published empirical equations was conducted in order to evaluate the assumed effective strains. The empirical equations were found to be unconservative. Nonlinear finite element (NLFE) models were developed for the beams. The models agreed with test results that targeting the B-region was more effective than distributing the same CFRP area in a discrete strip style over shear spans. Moreover, the numerical models predicted the contribution of different configurations better than the empirical equations.

Empirical formulations for evaluation of across-wind dynamic loads on rectangular tall buildings

  • Ha, Young-Cheol
    • Wind and Structures
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    • 제16권6호
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    • pp.603-616
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    • 2013
  • This study is aimed at formulating an empirical equation for the across-wind fluctuating moment and spectral density coefficient, which are needed to estimate the across-wind dynamic responses of tall buildings, as a function of the side ratios of buildings. In order to estimate an empirical formula, wind tunnel tests were conducted on aero-elastic models of the rectangular prisms with various aspect and side ratios in turbulent boundary layer flows. In this paper, criteria for the across-wind fluctuating moment and spectral density are briefly discussed and the results are analyzed mainly as a function of the side ratios of the buildings. Finally, empirical formulas for the across-wind fluctuating moment coefficient and spectral density coefficient according to variation of the aspect ratio are proposed.

학습조직, 제안활동, 6시그마 성과 간 연관관계에 관한 실증 연구 (An Empirical Study on Associations among Learning Organization, Suggestion Activities, and Six Sigma Performance)

  • 유지수;김주영;김혜정
    • 품질경영학회지
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    • 제37권3호
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    • pp.54-64
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    • 2009
  • This study conducts an empirical analysis of how the suggestion activity, most widely used in quality control activities, interacts with the dimensions of learning organizations. The study also attempts to analyze the results of Six Sigma based on sub-dimensions of learning organizations, which are infrastructure, culture and system. In order for learning and innovation to take place in implementing a Six Sigma program, the organizational infrastructure and culture are created and sustained and then, a learning organization system would become effective. In this study, a empirical model is used to demonstrate such an association. The sample consists of 134 organizations who have implemented a Six Sigma program for more than three years. Using the version 16.0 of AMOS for structural equation modeling, the study estimates the structural equation model that has a Six Sigma organization's infrastructure, culture and system as independent constructs, the suggestion system as a mediator, and the performance of Six Sigma projects as a dependent construct.