• Title/Summary/Keyword: weight system

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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%.

A Study on the Analysis of the Weight Estimation of Built Naval Ships (실적 함정의 중량추정 분석 연구)

  • Kim, Jongchul;Ko, Youngseok;Kim, Taehoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.4
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    • pp.526-535
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    • 2016
  • In this study, the estimating weight data of eight leading ships of Korea navy were processed by comparing with the final weight data of their incline test results statistically, and are analyzed as follows; The maximum criteria of the weight margins of Korea naval ship in the preliminary and detailed design phases seem to be appropriate values, but the minimum criteria would be advisable to update more reasonable values. And, the limitation that the acceptable deviation of lightship weight should be 10 % of the lightship weight on a naval ship's ROC(Required Operational Capabilities) is recommended to be prohibited, because it comes from the weight estimation which has considerable uncertainty and it may also drop off design flexibility. Finally, the SWBS(Ship Work Breakdown System) groups which have larger deviation values in the estimating weight of naval ships are necessary to improve their accuracies, and to upgrade their weight database continuously.

Studies on the Improvement of Embryo Transfer Efficiency in Korean Cattle IV. Effect of the Gestation Length and the Weight Changes of Calves Produced after Embryo Transfer (한우에서 수정란 이식의 효율 증진에 관한 연구 IV. 수정란 이식 송아지의 임신기간 및 체중변화에 미치는 영향)

  • 김흥률;김덕임;원유석;김경주;권항기;김창근
    • Journal of Embryo Transfer
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    • v.14 no.3
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    • pp.155-162
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    • 1999
  • This study was carried out to establish an effective system for embryo transfer of techniques by analyzing several factors affecting the gestation length and the weight changes of calves produced from embryo transfer in Korean cattle. The results obtained in study on factors affecting the gestation length and the weight changes of calves produced from embryo transfer were as fallow; 1) The gestation length and the birth weight did not differ between male and female, but the weight changes after birth were remarkablely different between sex(P<0.05). 2) The gestation length between heifers and cows was not different, and body weights at birth and 6 months were remarkabley heavy in cows(P<0.05). Weight changes after 6 months were not different. 3) The gestation length and the birth weight were significantly different between the single and twin calving (P<0.05). Weight of twin at 6 and 12 months were remarkabely light. 4) Calving seasons did not affect the gestation length the and the birth weight. Weaning weight was significantly heavy(P<0.05), but weight changes after weaning were no different among the calving seasons. Conclusivley, this results suggest that cows will be better when considering growth of calves and twin produced from embryo trnsfer in Korean cattle.

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Review on Predictors of Weight Loss in Obesity Treatment (비만 치료에 있어서 체중 감량에 영향을 주는 인자들에 대한 고찰)

  • Nam, Seung-Hee;Kim, Seo-Young;Lim, Young-Woo;Park, Young-Bae
    • Journal of Korean Medicine for Obesity Research
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    • v.18 no.2
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    • pp.115-127
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    • 2018
  • Objectives: People often fail to reduce or maintain their weight despite trying to lose weight. The purpose of this study was to review previously published study results of the predictive factors associated with weight loss in obesity treatment. Methods: Authors searched for the articles related to weight loss, published from 2007 to 2017 found on PubMed, Scopus, Research Information Sharing Service (RISS), and Koreanstudies Information Service System (KISS). A total of 43 articles were finally selected. From the study results, unchangeable and changeable predictors were extracted, and these predictors were examined according to detailed categories. Results: Predictors of weight loss in obesity treatment included genetic and physiological factors, demographic factors, history of treatment on obesity related factors, behavioral factors, psychological factors and treatment process related factors. The main factors of weight loss were unchangeable predictors such as high initial degree of obesity and younger age, and changeable predictors such as dietary restraint, regular exercise, self-efficacy, initial weight loss and attendance. Especially dietary restraint, regular exercise, successful initial weight loss and high attendance were considered to be dominant factors for weight loss treatments. Conclusions: Our review results suggest that unchangeable and changeable predictors of weight loss should be carefully examined during treatments of obesity.

On the Effect of Significance of Correlation Coefficient for Recommender System

  • Lee, Hee-Choon
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1129-1139
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    • 2006
  • Pearson's correlation coefficient and vector similarity are generally applied to The users' similarity weight of user based recommender system. This study is needed to find that the correlation coefficient of similarity weight is effected by the number of pair response and significance probability. From the classified correlation coefficient by the significance probability test on the correlation coefficient and pair of response, the change of MAE is studied by comparing the predicted precision of the two. The results are experimentally related with the change of MAE from the significant correlation coefficient and the number of pair response.

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80000 RPM용 고속회전축계의 최적설계에 관한 연구

  • 김종립;윤기찬;하재용;박종권
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.312-317
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    • 1997
  • This paper present an optimum design for the rotor-bearing system of a high-speed (80000RPM) ultra-centrifuge supported by ball bearings with nonlinear stiffness characteristics. To obtain the nonlinear bearing stiffnesses, a ball bearing is modelled in five degrees of freedom and is analyzed quasi-statically. The dynamic behaviors of the nonlinear rotor-bearing system are analyed by using a transfer-matrix method iteratively. For optimum design, minimizing the weight of a rotor is used as a cost function and the Augmented Lagrange Multiplier (ALM) method is employed. The result shows that the rotor-bearing system is optimized to obtain 8% weight reduction.

Structural Safety Evaluation System of Existing low-rise Reinforced Concrete Buildings to Remodeling (리모델링을 위한 기존 저층형 철근콘크리트의 안전성 평가 시스템)

  • 김진수;김창은
    • Journal of the Korea Safety Management & Science
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    • v.5 no.3
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    • pp.69-80
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    • 2003
  • This study researched problems of safety inspection method and current legislative system for the structure safety evaluation of Rahmen structure affected by remodeling. The elements of weight increase were examined in terms of differences of load moment, shear force, compressive stress and amount of steel before and after remodeling by structure analysis. The thorough examination for impacts of weight increase is indispensable to change of use or extension.

The Relationship Between Asymmetrical Weight Bearing and Bone Mineral Density in Chronic Hemiplegic Limbs

  • Shin, Hwa-Kyung;Kim, Tae-Ho
    • Physical Therapy Korea
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    • v.16 no.4
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    • pp.31-36
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    • 2009
  • Hemiplegia-induced immobilizatoin and reduction of mechanical loading in chronic stroke limbs are common cause of disuse osteoporosis. The purpose of this study was to investigate the effects of asymmetrical weight bearing on the loss of bone mineral in the individual with chronic stroke. Sixteen hemiplegic patients with strokes were evaluated. The measurements of bone mineral density (BMD) were evaluated with the quantitative ultrasound system on the calcaneus region of the paretic and non-paretic side. Plantar pressure was measured using the Mat-Scan system. The paretic side showed significantly smaller values in the T-score of BMD, and peak value of plantar pressure, which included forefoot, midfoot, and hindfoot, than the non-paretic side (p<.05). Results from the pearson correlation analysis showed statistically significant correlation between the BMD difference and the peak-pressure difference of midfoot pressure (p<.05). This finding indicated that BMD loss depended on decrease of body weight born on the paretic leg.

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Developing the Light-weight PV Blind System and the Shading Analysis by the Control Conditions (경량 태양광발전 블라인드 개발 및 제어조건에 따른 음영분석)

  • Chung, Yu-Gun
    • KIEAE Journal
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    • v.15 no.1
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    • pp.83-88
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    • 2015
  • This study aims to develope the light-weight PV blinds with windows and to investigate the shading analysis by the control conditions. For the study, the polycarbonate characteristics and coating methods are analyzed and the PV blind design for a small office is suggested. Also, the mock-up model of a suggesting system was made. The field tests were controled based on a solar altitude under clear sky conditions. As results, it is necessary to use a polycarbonate instead of a tempered glass for a light-weight PV. The shading effects of blind systems are high in slat angle $30^{\circ}$ and low in $0^{\circ}$. Also, the shading ratio is more affected by solar latitude than solar altitude. The shading change rate is relevantly constant on the solar altitude.

A Study on the Minimum Weight Design for Flexible Structure (유연구조물의 최소중량설계에 관한 연구)

  • 박중현
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.2
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    • pp.153-159
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    • 2004
  • A control-structure combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider not only minimum weight design problem for structure system, but also suppression problem of the effect of disturbances for control system as the purpose of the design. By minimizing the linear sum of the normalized structural objective function and control objective function, it is possible to make optimal design by which the balance of the structural weight and the control performance is taken.