• Title/Summary/Keyword: Statistical factor analysis

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Reliability Analysis of Reduction Factor for Structural Design Guideline(draft) of Fiber Reinforced High Strength Concrete (섬유보강 고강도 콘크리트 구조설계지침(안)의 저감계수에 대한 신뢰도 분석)

  • Kim, Ah-Ryang;Choi, Jungwook;Paik, Inyeol
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.1
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    • pp.100-108
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    • 2021
  • The purpose of this study is to analyze the reliability index of a design by applying the reduction factor of the recently developed fiber reinforced high strength concrete design guideline(draft). By collecting material and member test data performed for the development of the design guideline(draft), statistical characteristics of material strength and member strength analysis equations are obtained. A simul ation that appl ies the material statistical characteristics and the member anal ysis equation of the design guidel ine(draft) is performed, and the statistical characteristics of the section strength are calculated by combining the statistical characteristics of the analysis equation. Reliability analysis was performed by applying the load combination of the domestic highway bridge design code and concrete structural code, and it was confirmed that the design that applies the reduction factor for materials and members suggested in the design guideline(draft) satisfies the target reliability index.

An application of the Statistical Energy Analysis for Absorbing and Soundproofing Materials of Vehicle (자동차용 흡.차음재의 성능분석을 위한 통계적 에너지 기법 적용의 검정)

  • Lee, Chang-Myung;Lee, Jun;Kim, Dae-Gon;Jung, Byoung-In
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.1109-1113
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    • 2001
  • Interior parts of a vehicle are getting important to reduce interior noise of car. Therefore, prior analysis of cabin noise related with interior parts are necessary at first design stage. Recently, Statistical Energy Analysis(SEA) has been suggested as a possible way for meddle of high frequency range analysis with interior parts. This article introduces an example of the application of SEA to predict air born noise of cabin of car.

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Hybrid Type Vibration Power Flow Analysis Method Using SEA Parameters

  • Park, Young-Ho;Hong, Suk-Yoon
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.4E
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    • pp.164-169
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    • 2002
  • This paper proposes a hybrid method for vibration analysis in the medium to high frequency ranges using Power Flow Analysis (PFA) algorithm and Statistical Energy Analysis (SEA) coupling concepts. The main part of the developed method is the application of coupling loss factor (CLF) suggested in SEA to the power transmission, reflection coefficients in PI' A boundary conditions. The developed hybrid method shows very promising results with regard to the applications for the various damping loss factors in wide frequency ranges. And also this paper presents the applied results of Power Flow Finite Element Method (PFFEM) by forming the new joint element matrix with CLF to analyze the various plate structures in shape. The analytical results of automobile, complex plate structures show good agreement with those of PFFEM using the PFA coefficients.

Hybrid Type Vibration Power Flow Analysis Method Using SEA Parameters

  • 박영호;홍석윤
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.4
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    • pp.164-164
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    • 2002
  • This paper proposes a hybrid method for vibration analysis in the medium to high frequency ranges using Power Flow Analysis (PFA) algorithm and Statistical Energy Analysis (SEA) coupling concepts. The main part of the developed method is the application of coupling loss factor (CLF) suggested in SEA to the power transmission, reflection coefficients in PI' A boundary conditions. The developed hybrid method shows very promising results with regard to the applications for the various damping loss factors in wide frequency ranges. And also this paper presents the applied results of Power Flow Finite Element Method (PFFEM) by forming the new joint element matrix with CLF to analyze the various plate structures in shape. The analytical results of automobile, complex plate structures show good agreement with those of PFFEM using the PFA coefficients.

Statistical Approach to Test Construct Validity and Obtain Weights for the Children's Dietary Life Recognition and Practice Index (우리나라 초등학교 어린이의 식생활 인지.실천 수준 평가지표 구성타당도 평가 및 산정방법 연구)

  • Kwon, Se-Hyug;Kim, Hye-Young P.;Lee, Jung-Sug;Kwa, Tong-Kyung;Chung, Hae-Rang;Choi, Young-Sun;Kang, Myung-Hee
    • Journal of Nutrition and Health
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    • v.44 no.1
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    • pp.41-48
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    • 2011
  • Constructs with seven latent evaluation indicators and 18 observable survey questions were developed by food and nutrition experts to calculate a food safety recognition and practice index for children. The purpose of this study was to suggest statistical approaches to test construction validity on the constructs, obtain weights of the evaluation indicators, and develop questionnaires to calculate a children's food recognition and practice index. Survey data of 2,400 elementary fifth grade students were used as empirical results. Test validity was evaluated by exploratory factor analysis and confirmed to be highly significant by confirmatory factor analysis [i.e., linear structural relations (LISREL) analysis]. Standardized path coefficients of the LISREL analysis were suggested based on weights, and the weights were compared using the AHP and Delphi methods.

Investigation of dynamic P-Δ effect on ductility factor

  • Han, Sang Whan;Kwon, Oh-Sung;Lee, Li-Hyung
    • Structural Engineering and Mechanics
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    • v.12 no.3
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    • pp.249-266
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    • 2001
  • Current seismic design provisions allow structures to deform into inelastic range during design level earthquakes since the chance to meet such event is quite rare. For this purpose, design base shear is defined in current seismic design provisions as the value of elastic seismic shear force divided by strength reduction factor, R (${\geq}1$). Strength reduction factor generally consists of four different factors, which can account for ductility capacity, overstrength, damping, and redundancy inherent in structures respectively. In this study, R factor is assumed to account for only the ductility rather than overstrength, damping, and redundancy. The R factor considering ductility is called "ductility factor" ($R_{\mu}$). This study proposes ductility factor with correction factor, C, which can account for dynamic P-${\Delta}$ effect. Correction factor, C is established as the functional form since it requires computational efforts and time for calculating this factor. From the statistical study using the results of nonlinear dynamic analysis for 40 earthquake ground motions (EQGM) it is shown that the dependence of C factor on structural period is weak, whereas C factor is strongly dependant on the change of ductility ratio and stability coefficient. To propose the functional form of C factor statistical study is carried out using 79,920 nonlinear dynamic analysis results for different combination of parameters and 40 EQGM.

A SEA Modeling of a compact car and Interior Noise Analysis (소형 승용차량의 SEA 모델링 및 내부 소음 연구)

  • Kim, Sang-Su;Kim, Kwan-Ju;Lim, Hyo-Suk;Kim, Young-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.824-828
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    • 2007
  • In this paper Statistical Energy Analysis has been considered to predict middle, high frequency air borne interior noise. PIM method is used for verification. Damping loss factor and coupling loss factor have been derived from the response(SPL) of sub systems when the power is applied. The airborne SEA model of vehicle is modeled through AutoSea2. Insulation material's absorption coefficient and transmission loss are acquired from closed form solution and experiment.

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A Bayesian Diagnostic Measure and Stopping Rule for Detecting Influential Observations in Discriminant Analysis

  • Kim, Myung-Cheol;Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.29 no.3
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    • pp.337-350
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    • 2000
  • This paper suggests a new diagnostic measure and a stopping rule for detecting influential observations in multiple discriminant analysis (MDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the fractional Bayes factor methodology. The Bayes factor is taken as a discriminatory information in MDA. It is shown that the effect of an observation over the discriminatory information is fully explained by the diagnostic measure. Based on the measure, we suggest a stopping rule for detecting influential observations in a given training sample. As a tool for interpreting the measure a graphical method is sued. Performance of the method is used. Performance of the method is examined through two illustrative examples.

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Added Mass Effect on Structural Junction: Comparison of SEA Experimental Results with Analysis (구조물 연결부의 질량부과 효과 : SEA실험 및 해석 결과 비교)

  • 김관주;김정태;윤태중;박봉현
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.359-364
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    • 2002
  • Statistical energy method is widely used for the prediction of vibrational and acoustical behavior of complex structures, such as ship building and automobile in mid-, high frequency ranges. However. in order to convince this SEA result, it is important to verify estimated SEA parameters, e. g. modal density, energy in each subsystem, damping loss factor, coupling loss factor. with possible other method. For modal density parameter, the experimental estimations via Experimental Modal Analysis are checked with those from finite element method for both beam- plate and plate-plate cans. Loss factors are calculated by Lyon's simple method for the two subsystem. finally. modal experiments are carried out by varying the mass added on the junction of two subsystem for the purpose of investigating the influence on the coupling loss factor's behavior.

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Service Quality assessment for Food & Beverage Product of Hotel (관광호텔 식음료상품 서비스품질 평가)

  • 김승희
    • Culinary science and hospitality research
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    • v.5 no.2
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    • pp.447-467
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    • 1999
  • Most published work on product quality focuses on manufactured goods. The subject of service quality has received less attention. This distinction is important because some of the quality-improving strategies avaliable to manufacturers may be inappropriate for service firms. Services are performances, not objects. They are often produced in the presence of the customer, as in the cause of hotel restaurant services, quality occurs during service delivery, usually in an interaction between the customer and contact personnel of service firm. for this reason, service quality is highly dependent on the performance of employees, an organizational resource that cannot be controlled to the degree that components of tangible goods can be engineered. The study has begun as a basic study for customer satisfaction-oriented management in understanding the service quality of food & beverage products and through a systematic analysis of it. The major purpose of the study was to examine the relationship of the customer satisfaction and service quality in consideration of reliability, empathy, responsiveness, tangibility and assurance. An empirical research was conducted based on the previous theoretical studies. 286 customer at first class hotels in Seoul were selected as samples of this study. The time period of research was from February through March 1999, and answers were processed by SAS to yield frequency analysis, multivariate statistical analysis and regression analysis. The finding of the statistical treatment are frequencies, factor analysis, multiple regression analysis, path analysis. SERVQUAL method was used the service quality evaluation methods. After factor analysis, it was resulted to 3 factors. those were factor 1(assurance.empathy.responsiveness), factor 2(reliability), factor 3(tangibility). The findings of the statistical treatment are as follows. First, the attribute measurement of performance service quality was affected by customer satisfaction. Second, the attribute measurement of performance service qualify was affected by repurchase intention. Third, The attribute measurement of performance customer satisfaction was affected by repurchase intention. The result of study model was followed, service quality was affected repurchase intention than customer satisfaction. indirected effect through, service duality and customer satisfaction was affected repurchase intention.

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