• Title/Summary/Keyword: weight analysis

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A Study on Statistical Methods for the Light Weight Estimation of Ultra Large Container Ships (초대형 컨테이너선의 경하중량 추정을 위한 통계적 방법 연구)

  • Cho, Yong-Jin
    • Journal of Ocean Engineering and Technology
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    • v.23 no.3
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    • pp.14-19
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    • 2009
  • The present study developed a model to estimate the light weight of an ultra-large container ship. The weight estimation model utilized container ship data obtained from shipyards and the subdivided this weight data into appropriate weight groups. Parameters potentially affecting the group weight were selected and expanded based on experience for weight estimation, and a correlation analysis was performed by the SPSS program to determine the key parameters characterizing the group weight. A weight estimation model applying the multi-regression analysis was proposed to assess the weight of an ultra-large container ship at the preliminary design stage, and the results obtained by the suggested method showed good agreement with the shipyard data.

Light weight vehicle design by stick model (스틱모델에 의한 차체 경량화 설계)

  • 김천욱;김지홍
    • Journal of the korean Society of Automotive Engineers
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    • v.12 no.5
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    • pp.97-106
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    • 1990
  • A method of weight evaluation of the load-bearing structural elements of cars is presented and the weight ratio of the analysis model is investigated. Replacing the materials of floor elements of the car into the high-strength steel, a considerable weight-reduction of the model has been obtained. The 1500cc model is selected for the present study and the stick model analysis is employed for the structural analysis. The torsional stiffness of the weight-reduced model is also evaluated and it is shown it has a reasonable rigidity. The ratio of the weight of the load-bearing structural elements to the unladen vehicle weight of cars is about 0.12for the 1500cc model and the weight-reduction of this study can be obtained around 17% of the weight of the load-bearing structural elements.

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Design and Structural Analysis of Long Pull Weight Machine (롱풀 웨이트 기구의 설계 및 구조해석)

  • 이종선;홍석주
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.73-77
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    • 2004
  • This study is object to design and structural analysis of Long Pull weight machine. Structural analysis of Long Pull weight machine using result from ANSYS code. This structural analysis results, many variables such as boundary condition, constraints and load condition were considered.

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The numerical analysis of heavy-weight impact noise for an apartment houses considering acoustic mode (Acoustic mode 를 고려한 공동주택 중량충격음 소음해석)

  • Mun, Dae-Ho;Hwang, Jae-Seung;Park, Hong-Gun;Hong, Geon-Ho;Im, Ju-Hyeuk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.04a
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    • pp.394-402
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    • 2009
  • To investigate the heavy-weight impact noise of apartment houses, numerical analysis was performed. The analysis acoustic pressure consider acoustic mode by finite element method. The variables considered effecting on the acoustic pressure are the Acoustic mode, acoustic damping, and the impulse load. The heavy-weight impact noise is a changeable value in the room. Since the most part of the frequency component of heavy-weight impact noise has low frequency. The noise in low frequency is related to the vibration of structure, the reflection of acoustic wave caused by wall and the standing wave called by acoustic mode. The prediction by the numerical analysis was verified with test result of the heavy weight-impact noise at apartment houses.

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Structural Optimization of a Light-weight Manhole Cover Using FEM and Response Surface Method (유한요소법과 반응표면법을 이용한 경량 맨홀 커버 구조 최적화 설계)

  • Lee, Hyoungwook
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.6
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    • pp.462-470
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    • 2016
  • The locking load of a conventional manhole depends on the weight of its cover. Locking-type manhole structures with a special locking mechanism were recently developed to prevent accidents such as stolen cover, away cover from a frame. The weight of the manhole structure can be reduced under structural safety because the locking force of a locking-type manhole is greater than the weight of the cover. A light-weight manhole cover is developed in this study by using a finite element stress analysis and the design of experiments. Static stress analysis and fracture experiments are also conducted to analyze the states of the initial product. The optimum light-weight manhole cover considering manufacturing molds is developed and tested. Consequently, the weight was found to reduce by 16%. In addition, the fracture load increased by 38%.

An Analysis of Research on Postpartum Weight Retention (산후체증정체(Postpartum Weight Retention)관련 국외 연구논문 분석)

  • Lee, Seoung-Eun;Yoo, Eun-Kwang
    • Women's Health Nursing
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    • v.9 no.3
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    • pp.287-298
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    • 2003
  • Purpose: To explain the concept of postpartum weight retention and to analyze factor effect on it. Method: A total of 20 studies related postpartum weight retention were selected in the year of 1988-2001 and analysis was done. Result: A demographic factor like parity, age, social and economic level and life style such as exercise, diet, breast feeding are influential factor on postpartum retention weight. But parts of them don't agree the same results. Meanwhile, in some studies, psychological factor like women's self esteem related to postpartum retention weight, body image change, depressing is found to be very related. As a result, postpartum overweight gain could be a bad factor of physical and mental health. In Korea, we have few studies related to them. Conclusion: It is required to do many-sided and deep studies about aspects of postpartum retention weight and the factor that effect on it. Postpartum retention weight should be approached by controling weight from the period of pregnancy. And it would rather be researched through individual approach considered women's various demographic, social-cultural and physical level than be required standardized level of weight gain.

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A Development of the Ship Weight Estimating Method by a Statistical Approach (통계적 접근법에 의한 선박 중량추정 방법 개발)

  • Cho, Yong-Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.5
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    • pp.426-434
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    • 2011
  • Accurate weight prediction methods are an essential of the ship design in both ship cost managements and performance satisfactions. When no parent or similar ships are available, an adequate method of the ship weight estimating is required. In this study, there was carried out to develop the ship weight estimating method for the preliminary design phase. The weight estimating methods were first surveyed by the references and summarized their characteristics. The weight estimation method by statistical approach was developed for the container ship because the containerized transportation markets is gradually growing and ship's size and loading capacity are rapidly enlarged. The correlation analysis and the multiple regression analysis were used for developing the weight estimating method. As a results of evaluating the developed method, the error ratio of the variation between estimated weight and ship's data was about 5%. And it was only 1% difference with the calculating weight of conceptual design results by shipyard design team that the estimating weight of ultra-large container ship was predicted by the developed method.

Multilevel Analysis of Factors associated with Subjective Weight Perception among Normal Body Weight Adolescents based on the 2017 Korean Youth's Risk Behavior Survey (KYRBS) (정상체중 청소년의 주관적 체형인식 관련요인 다수준 분석: 2017년 청소년건강행태온라인조사 자료를 중심으로)

  • Joeng, Eun Ha;Lee, In Sook
    • Research in Community and Public Health Nursing
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    • v.29 no.4
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    • pp.476-487
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    • 2018
  • Purpose: The present study is focused on understanding weight perception related with individual- and school-level multifactorial origins, underestimated and overestimated respectively, in normal body weight adolescents. Methods: Using the 2017 Korea Youth Risk Behavior Web-based Survey data of 45,902 students from 799 secondary schools, a multilevel multinomial logistic regression analysis was performed where adolescents (level1) were nested within schools (level 2). Results: At the school level, the average school body mass index (BMI, $kg/m^2$) and physical education were associated with weight perception among both boys and girls. In boys, geographic areas were associated with weight underestimation. At the individual level, perceived economic status, weekly allowance, BMI ($kg/m^2$), smartphone usage time (hrs/day) and perceived stress were associated with weight perception among both boys and girls. Age, paternal education, academic achievement and alcohol use were associated with weight perception among girls, while part-time job and physical activity were associated with weight perception among boys. Conclusion: Our findings underscore the importance of individual- and school-level environments in developing correct weight perception and have implications for school health education to establish healthy lifestyle behaviors for all adolescents.

Comparison of Customer Satisfaction Indices Using Different Methods of Weight Calculation (가중치 산출방법에 따른 고객만족도지수의 비교)

  • Lee, Sang-Jun;Kim, Yong-Tae;Kim, Seong-Yoon
    • Journal of Digital Convergence
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    • v.11 no.12
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    • pp.201-211
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    • 2013
  • This study compares Customer Satisfaction Index(CSI) and the weight for each dimension by applying various methods of weight calculation and attempts to suggest some implications. For the purpose, the study classified the methods of weight calculation into the subjective method and the statistical method. Constant sum scale was used for the subjective method, and the statistical method was again segmented into correlation analysis, principal component analysis, factor analysis, structural equation model. The findings showed that there is difference between the weights from the subjective method and the statistical method. The order of the weights by the analysis methods were classified with similar patterns. Besides, the weight for each dimension by different methods of weight calculation showed considerable deviation and revealed the difference of discrimination and stability among the dimensions. Lastly, the CSI calculated by various methods of weight calculation showed to be the highest in structural equation model, followed by in the order of regression analysis, correlation analysis, arithmetic mean, principal component analysis, constant sum scale and factor analysis. The CSI calculated by each method showed to have statistically significant difference.

A Study on the Weight Estimation Model of Floating Offshore Structures using the Non-linear Regression Analysis (비선형 회귀 분석을 이용한 부유식 해양 구조물의 중량 추정 모델 연구)

  • Seo, Seong-Ho;Roh, Myung-Il;Shin, Hyunkyoung
    • Journal of the Society of Naval Architects of Korea
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    • v.51 no.6
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    • pp.530-538
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    • 2014
  • The weight estimation of floating offshore structures such as FPSO, TLP, semi-Submersibles, Floating Offshore Wind Turbines etc. in the preliminary design, is one of important measures of both construction cost and basic performance. Through both literature investigation and internet search, the weight data of floating offshore structures such as FPSO and TLP was collected. In this study, the weight estimation model was suggested for FPSO. The weight estimation model using non-linear regression analysis was established by fixing independent variables based on this data and the multiple regression analysis was introduced into the weight estimation model. Its reliability was within 4% of error rate.