• 제목/요약/키워드: Structural Weight

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A Study on the Structural Design of Effective Composite Joint and Light Weight in Body Floor (Body Floor의 복합재 접합방식 및 경량화 설계에 관한 연구)

  • Kim, Hong Gun;Oh, Sang Yeob;Kim, Kwang Choul;Kim, Hyun Woo;Kwac, Lee Ku
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.6
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    • pp.920-925
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    • 2012
  • A study of vehicle weight lightening has been progressed to reduce the fuel consumption. In this paper, the body floor in an EV (Electric Vehicle) bus has been applied by composites as CFRP and GFRP. In order to analyse a various reliability and safety, an experiment and FEM analysis was carried out to obtain weight lightening. Especially, the joint. An effective design is obtained through an experiment as well as FEM analysis. Results of stress analysis of GFRP material showed twice as much displacement than those of CFRP material. Among three kinds of joint methods, the bond joint method is occurred to a substantial shape change in the body and floor. It is found that the rivet joints are fairly suitable for stress sustaining capability.

Development of Lightweight Aluminum I Type Radius Rod for Heavy Trucks (대형 트럭용 경량 알루미늄 I형 래디어스 로드 개발)

  • Choi, Gyoo-Jae;Lee, Keen-Yeong;Ha, Tae-Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.6
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    • pp.58-64
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    • 2008
  • An aluminum radius rod using rheo-forging method has been developed for heavy commercial vehicles to decrease vehicle unsprung weight. To design the shape of the rod, structural simulations are performed using two load cases. To evaluate durability performance of the rods, a test system which has simultaneous 3 axes actuating system is developed. And 3 axes durability test conditions are established based on vehicle field tests. Using the test systems and the conditions, the durability test is carried out and the rods have passed the test conditions of 700,000 cycles. The weight of a developed aluminum radius rod is 4.2kg and it was drastically reduced by 48.8 percent in comparison with the weight of a steel radius rod.

Minimum Weight Design of Transverse Frames of Oil Tankers by Generalized Slope Deflection Method (일반화 경사처짐법에 의한 유조선 횡강도 부재의 최소 중량 설계)

  • Chang-Doo Jang;Seung-Soo Na
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.3
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    • pp.103-111
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    • 1996
  • A generalized slope deflection method has already been developed by the authors from the existing one, and applied to the 3-dimensional structural analysis of tankers idealized as frame models to verify the effectiveness of the method from the analysis viewpoint. In this study, a minimum hull weight design program of tankers is developed to verify the effectiveness of the method from the design viewpoint by the combination of generalized slope deflection method and optimization method considering discrete design variables. By this program, it is possible to determine the scantling of each member of actual tankers that give minimum weight under given constraints. Also, a considerable weight saving has been found compared with existing ship.

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A Study on the Optimum Design of Cargo Tank for the LPG Carriers Considering Fabrication Cost (건조비를 고려한 LPG 운반선 화물창의 최적설계에 관한 연구)

  • Shin, Sang-Hoon;Hwang, Sun-Bok;Ko, Dae-Eun
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.2
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    • pp.178-182
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    • 2011
  • Generally in order to reduce the steel weight of stiffened plate, stiffener spaces tend to be narrow and the plate gets thin. However, it will involve more fabrication cost because it can lead to the increase of welding length and the number of structural members. In the yard, the design which is able to reduce the total fabrication cost is needed, although it requires more steel weight. The purpose of this study is to find optimum stiffener spaces to minimize the fabrication cost for the cargo tank of LPG Carriers. Global optimization methods such as ES(Evolution Strategy) and GA(Genetic Algorithm) are introduced to find a global optimum solution and the sum of steel material cost and labor cost is selected as main objective function. Convergence degree of both methods in according to the size of searching population is examined and an efficient size is investigated. In order to verify the necessity of the optimum design based on the cost, minimum weight design and minimum cost design are carried out.

Ripening Related Changes in Hot Pepper Fruit Cell Walls Structural Alterations of Cell Wall Polysaccharides and Separation of Galactosidase Isozymes (고추의 성숙에 따른 세포벽 다당류의 변화와 ${\beta}-Galactosidase$ Isozymes의 분리)

  • Kim, Soon-Dong;Kang, Meung-Su;Kim, Kwang-Soo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.14 no.2
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    • pp.157-163
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    • 1985
  • Various cell wall polysaccharides and related enzyme activities in hot pepper fruit were determined at different stages of maturity. The uronic acid content of cell walls decreased between immature green and turning stage fruit and then increased by red ripe stage. In contrast, cellulose content of cell walls changed only a little during ripening. Total neutal sugar content of cell wall material decreased 50% and galactose content of the walls decreased about 80% by the turning stage. Polygalacturonase and ${\beta}-galactosidase$ activities, as well as total hemicellulose from isolated cell walls of ripening hot pepper fruit were studied using gel filtration chromatography. Polygalacturonase activity was not detectable but 5 isozymes of ${\beta}-galactosidase$ were resolved. The activities of the enzymes were relatively high and gel filtration showed that they differed in molecular weight. Hemicellulose content decreased during ripening and softening. The molecular weight profiles shifted from high molecular weight to low molecular weight polymers during ripening. The changes in cell walls that may be associated with fruit softening involve the alteration of hemicellulose prior to the degradation of wall-bound uronic acid. It is suggested that the decrease in cell wall galactose involved changes in turnover of new cell wall components.

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Standardization of Impact Test Methods of Non-bearing Lightweight Wall for Building (건축용 비내력 경량벽체의 내충격성 시험방법의 표준화)

  • Kim, Ki-Jun;Choi, Soo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.181-182
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    • 2015
  • The use of non-bearing light weight wall has increased recently due to the increase of high-rise buildings and supply of long-life housing. Light weight wall has advantages such as reducing the self-weight of the building, convenience in installation, and shortening construction period, however, must have a sufficient strength to external force. This study standardized the impact resistance test method for light weight walls by using the actual impact load obtained through load analysis test in previous studies. The impact resistance test method was divided into the test method that uses soft body and the one that uses hard body. The size of specimen was set up as height 2.4m and width 3.0m. The size and shape of the body followed those used in BS 5234-2 and so on for the compatibility with the test method used overseas. The judgment criteria for impact resistance based on test results were not defined uniformly as the assessment of functional damage can vary depending on the type of material, structural method, purpose of wall, and so on even when the same impact load was applied.

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Utilization of Kenaf Cultivated in Korea(I) - Growth and Anatomical Characteristics of Kenaf Cultivated in Korea - (국내산 Kenaf 이용에 관한 연구(제1보) -국내에서 재배한 kenaf의 생장 및 해부학적 특성-)

  • 이명구;윤승락
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.4
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    • pp.68-74
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    • 2003
  • Kenaf(Hibiscus cannabinus L.) cultivar, Tainung 2, had been grown for 152 days at the experimental farm of Jinju National University, Gajoa-dong, Jinju-si, Kyongnam, Korea. The planting, growth rate, fertilization and structural characteristics as well as the cultivation and growth characteristics of kenaf, and the product usage were investigated. The narrowest diameter at kenaf bottom was 10 mm, the widest 42 mm and the average about 28 mm, and the shortest height 150 cm, the tallest 480 cm and the average about 350 cm. The weight of a core fraction was 68.1% and a bast fraction 31.9%. The weight ratio of core material to bast fiber was 2.31. The weight ratio of dry stem was 73.5% and that of leaves 26.5%. The weight of dry plant produced in 1 $m^2$ was 1,467 g, and about 1,052 g of stem could be used for the commercial purpose, The application of fertilizers resulted in the increase of the growth rate of the diameter at plant bottom and the height. Bast fiber, phloem ray and cortex parenchyma cell were observed in bast, and vessel, wood fiber and ray in core.

Investigation of Retail Therapy (RT) Values -How Body Consciousness Plays a Role in Therapeutic Shopping Motivations-

  • Lee, Sea Eun;Yoo, Jeong-Ju
    • Journal of the Korean Society of Clothing and Textiles
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    • v.45 no.4
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    • pp.714-726
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    • 2021
  • The purpose of this study is to investigate the effect of retail therapy (RT) values and the role of body consciousness on therapeutic shopping motivations and outcomes. In order to accomplish our research aim, we investigated therapeutic shopping values (i.e., positive mood reinforcement and negative mood reduction) and the moderating effects of body surveillance, body shame, and weight preoccupation. A total of 247 female college students in the United States participated in an online Qualtrics survey, and structural equation modeling (SEM) and multigroup analysis were performed to analyze the data. The findings reveal that therapeutic shopping values (positive mood reinforcement and negative mood reduction) significantly influence therapeutic shopping motivation. Therapeutic shopping motivation, in turn, positively influences therapeutic shopping outcomes. Moreover, weight preoccupation moderates the relationship between negative mood reduction and therapeutic shopping motivation, suggesting that RT should especially be utilized for weight-conscious individuals. The results can be utilized for retailers to develop marketing strategies for consumers who are conscious about their appearance. Academic and managerial implications, along with future research, are suggested.

Protective Effect of Atractylodes macrocephala and Taraxacum spp. Combination Treatment in Balb/c Mice with Dextran Sulfate Sodium-Induced Ulcerative Colitis

  • Lee, Donghun;Kim, Hocheol
    • The Korea Journal of Herbology
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    • v.32 no.3
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    • pp.79-87
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    • 2017
  • Objectives : This study aimed to investigate the protective effects of an herbal mixture of Atractylodes macrocephala and Taraxacum spp. (ATC) on ulcerative colitis. We have previously screened traditional medicinal herbs to discover the effective candidate by the animal model. A. macrocephala and T. spp were identified as one of the effective herbs in the screening process. Methods : Experimental colitis was induced in male Balb/c mice by administering drinking water containing dextran sulfate sodium, which mimics the clinical and histological features of ulcerative colitis in human. ATC at doses of 30, 100 or 300 mg/kg were orally administered to mice twice per day for 10 consecutive days. To evaluate the damage from experimentla ulcerative colitis, body weight, colon length, disease activity index, myeloperoxidase and histological changes were measured and analyzed. Results : The administration of dextran sulfate sodium with drinking water resulted in markedly reduced colon length, severe body weight loss, increased levels of myeloperoxidase activity and histological damages in mice. ATC treatment significantly ameliorated the colon shortening, histological damage, body weight loss and disease activity index score in a dose-dependent manner. ATC also attenuated the colonic myeloperoxidase activity which reflects the severity and extent of inflammatory damage of colon. Conclusions : ATC exerts protective effects against inflammatory colonic structural damage induced by epithelial barrier integrity impairment. ATC also inhibits weight loss and related symptoms of UC which can be considered as the functional recovery of colon.

Influence of dietary nonstructural carbohydrate concentration on growth performance and carcass characteristics of Holstein steers

  • Ramos-Avina, Daniel;Plascencia, Alejandro;Zinn, Richard
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.6
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    • pp.859-863
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    • 2018
  • Objective: Since very little information exists about the topic; in this experiment we compare, in a long-term finishing program, the growth-performance responses and carcass characteristics of Holstein steers where non-structural carbohydrate concentration of the diet is reduced from 64% to 51% (dry matter basis). Methods: Sixty Holstein steer calves ($129{\pm}2.2kg$) were blocked by initial weight into five groups and randomly assigned within weight groupings to 10 pens. Calves were fed with a steam-flaked corn-based finishing diets containing 51% higher fiber (HF) or 64% lower fiber (LF) nonstructural carbohydrates. Non-structural carbohydrates concentrations were manipulated substituting dried distiller grain with solubles and alfalfa hay for flaked corn. Cattle were weighed every 112 days and at the end of the experiment (day 308) when the cattle were harvested and carcass characteristics were evaluated. Results: Steers fed the HF diet showed improvement (8.8%) in average daily gain (ADG) during the initial 112-d period. This effect was followed by a numerical trend for greater ADG throughout the remainder of the study so that overall ADG tended to be greater (4.9%, p = 0.06) for the HF than for LF. There were no treatment effects on dry matter intake. Gain efficiency and estimated dietary net energy (NE) were greater 8.3% and 5.2%, respectively for HF during the initial 112-d period. Overall (308-d) gain efficiency and estimated dietary NE were similar for both dietary treatments. However, due to differences in tabular dietary NE, the ratio of observed:expected dietary NE tended to be greater (4.1%, p = 0.06) for the HF vs LF diet. There were no treatment effects on carcass characteristics except for a tendency toward a slightly greater (0.5%, p = 0.09) estimated carcass yield. Conclusion: Reducing the non-structural carbohydrate concentration of a conventional steam-flaked corn-based growing finishing diet for Holstein steers can effectively enhance growth performance, particularly during the early growing and late finishing phases.