• Title, Summary, Keyword: sizing

Search Result 1,198, Processing Time 0.041 seconds

Optimization Design of Solar Water Heating System based on Economic Evaluation Criterion using a Genetic Algorithm (유전알고리즘 이용 경제적 평가기준에 따른 태양열급탕시스템 최적화 설계에 관한 연구)

  • Choi, Doosung;Ko, Myeongjin;Park, Kwang-Tae
    • Journal of the Korean Solar Energy Society
    • /
    • v.36 no.5
    • /
    • pp.73-89
    • /
    • 2016
  • To assure maximum economic benefits and the energy performance of solar water heating systems, the proper sizing of components and operating conditions need to be optimized. In recent years, a number of studies to design optimally solar water heating systems have been tried. This paper presents a design method for optimizing the various capacity-related and installation-related design variables based on life cycle cost using a genetic algorithm. The design variables considered in this study included the types and numbers of solar collector and auxiliary heaters; the types of storage tanks and heat exchangers; the solar collector slope; mass flow rates of the fluid on the hot and cold sides. The suggested method was applied for optimizing a solar water heating system for an elementary school in Seoul, South Korea. In addition, the effectiveness of the proposed optimization method was assessed by analyzing the obtained optimal solutions of six case studies, each of which was simulated with different solar fractions. It is observed that a trade-off between the equipment cost and the energy cost results in an optimal design that yields the lowest life cycle cost. Therefore, it could be helpful to apply the optimal solar water heating system by comparing the various design solutions obtained by using the optimization method instead of the engineer's experience and intuition.

Lower Body Type Classification by Buttocks Shapes of Korean Women in Their 20's (국내 20대 여성의 엉덩이 형태에 따른 하반신 체형 분류)

  • Choi, Se-Lin;Do, Wol-Hee
    • Fashion & Textile Research Journal
    • /
    • v.18 no.3
    • /
    • pp.327-337
    • /
    • 2016
  • The purpose of this study is for size suitability and fitness improvement for Korean 20's women. This study has classified hip types of 20's women by the 6th Korean Anthropometric Survey(Size Korean), then compared their lower body-type by hip types each other. The results are as follows. Factor analysis in sorting hip types can be explained 77.72% by nine factors. And cluster analysis can be divided into three types. Type 1 is referred to as a general type which has the largest size in the 'Hip circumference', but the buttocks's horizontal sizes are in the middle size besides the hip line. Type 2 is referred to as a protruding type in upper buttocks which is large in protruding volume of upper buttocks, but the buttock's horizontal sizes are small including 'Hip circumference', and buttock's horizontal section form close to circle. Type 3 is referred to as a type which is contrary to Type 2. Type 3 is small in protruding volume of upper buttocks, but large in lower buttocks, and the protrusions in whole buttocks are small, so the side view of Type 3 made gentle fit shape. By these results, the study could classify lower body of 20's women, and it can be basic data for new sizing systems and pattern development of bottoms.

Sizing Optimization of CFRP Lower Control Arm Considering Strength and Stiffness Conditions (강도 및 강성 조건을 고려한 탄소섬유강화플라스틱(CFRP) 로어 컨트롤 아암의 치수 최적설계)

  • Lim, Juhee;Doh, Jaehyeok;Yoo, SangHyuk;Kang, Ohsung;Kang, Keonwook;Lee, Jongsoo
    • Korean Journal of Computational Design and Engineering
    • /
    • v.21 no.4
    • /
    • pp.389-396
    • /
    • 2016
  • The necessity for environment-friendly material development has emerged in the recent automotive field due to stricter regulations on fuel economy and environmental concerns. Accordingly, the automotive industry is paying attention to carbon fiber reinforced plastic (CFRP) material with high strength and stiffness properties while the lightweight. In this study, we determine a shape of lower control arm (LCA) for maximizing the strength and stiffness by optimizing the thickness of each layer when the stacking angle is fixed due to the CFRP manufacturing problems. Composite materials are laminated in the order of $0^{\circ}$, $90^{\circ}$, $45^{\circ}$, and $-45^{\circ}$ with a symmetrical structure. For the approximate optimal design, we apply a sequential two-point diagonal quadratic approximate optimization (STDQAO) and use a process integrated design optimization (PIDO) code for this purpose. Based on the physical properties calculated within a predetermined range of laminate thickness, we perform the FEM analysis and verify whether it satisfies the load and stiffness conditions or not. These processes are repeated for successive improved objective function. Optimized CFRP LCA has the equivalent stiffness and strength with light weight structure when compared to conventional aluminum design.

The Survey on Froth Floatation of Low Grade Copper Ore from the Australia (호주산 저품위 동광의 부유선별에 관한 특성조사)

  • Kim, Joon Soo;Kim, Woo Jin;Hwang, Ha;Kim, Myong Jun;Kim, Wantae
    • Journal of the Korean Institute of Resources Recycling
    • /
    • v.25 no.6
    • /
    • pp.98-104
    • /
    • 2016
  • The purpose of this study is to obtain an optimum condition of the concentrate by floatation using Australian low grade copper ore of suitable particle size by crushing, grinding and sizing. The effect of the dosage of collector, activator, depressant and change of acidity on the floatation was investigated. The floatation conditions comprising of pH 9.0 acidity, 500g/t $CuSO_4{\cdot}5H_2O$ activator, 500g/t K.E.X. collector, 1500g/t $Na_2SO_3$ depressant and 25wt.% plup density were optimized. Grade and recovery of copper in the concentrate obtained by froth floatation under optimum conditions were 4wt.% and 65wt.% respectively.

A Study on the Apparel Sizing System of SPA brands (SPA 브랜드의 의류치수 사용 실태에 관한 연구)

  • Yi, Kyonghwa;Cho, Mina
    • Journal of Fashion Business
    • /
    • v.19 no.5
    • /
    • pp.139-156
    • /
    • 2015
  • The purpose of this study is to investigate various information relating to research on the dimensions of clothing used in the sale of products via the internet that used to target global SPA((Specialty Store Retailer of Private Label Apparel) brands sold in Korea. A total of 12 SPA brands including seven global SPA brands and five national. SPA brands were surveyed in this study. Brands were chosen net sales and consumer preferences the last three years. In all SPA brands, literal size designation such as S, M, L and numeric size designation such as 0, 2, 4 or 32, 34, 36 etc. were mixed, but in case of Jean, the size codes mark waist circumference were dominant. European size codes were more common in case of European brands while literal codes were more dominantly used for American size codes with in the US brands. By reviewing the measurement information of the body and product size, the product measurement methods of UNIQLO, FOREVER 21 and TOPTEN were much more accountable and excellent than other brands. However, most of the others didn't offer proper information such as pictograms or figures about measurement methods relating body sizes and product sizes. In addition, most of global SPA brands offered size conversion chart which consumers could reference, however of none of the national SPA brands offered a conversion size chart on their website. Regardless of the type of clothing, the coverage of clothing size was higher than in global SPA brands such as H&M GAP compared to national SPA brands. In particular, 8seconds did not present apparel size ranges that fit consumers' individual clothes sizes.

A Study on the Scale Effort Estimation Model based on Industry Characteristics (산업별 특성에 따른 소요공수 규모 산정 모델 연구)

  • Kwoak, Song-Hae;Park, Koo-Rack;Kim, Dong-Hyun
    • Journal of Digital Convergence
    • /
    • v.14 no.11
    • /
    • pp.233-240
    • /
    • 2016
  • Information system development projects, have a mechanism for many of the costs generated by a variety of risk factors. In general, the probability that the software project of the information system is carried out successfully in the delivery time is very low. This prediction of a formal cost is needed as the most important factor since it can prevent the project from being failed. However, objectivity of most of the project scale calculation during the calculation criteria is insufficient. Further, it is the actual situation that the management of the base line is not properly made during the project. Therefore, in this paper, we propose a model to calculate the number of steps it takes to develop on the basis of a methodology in an attempt to overcome the limitation of being unpractical in the early stage of the information system development project. It is expected to be a tool to estimate the effort and cost required by the information system development business through these convergence proposals model.

Investigation of Production Condition of Ready-Made and MTM Men's Suits - Focusing on Brands of Department Store - (신사 정장 브랜드의 기성복 및 MTM 생산 실태 조사 - 백화점 입점 브랜드를 대상으로 -)

  • Choi, Jin Young;Song, Hwa Kyung
    • Fashion & Textile Research Journal
    • /
    • v.18 no.6
    • /
    • pp.746-754
    • /
    • 2016
  • This study aimed to investigate the status of ready-made suit and MTM (Made-to-measure) suit production with 10 men's suit brands turning over 200 billion won. Their target age group is late 30's to late 40's. Regarding production for the ready-made suit, eight out of 10 brands are using both KS and their own sizing. Classification of body shapes was done in 8 brands, mostly for upper body in simple ways (lean, normal, and obese). All brands are conducting fittings on only standard size. The number of sizes produced is varying depending on the brands; 9 to 17 for a jacket and 9 to 20 for a pair of pants. Regarding on the MTM production, four out of 10 brands have implemented MTM production. The rate of MTM production to their total production is about 15-20%. There were positive opinions on MTM production since it enables to reduce stocks through a small quantity of production for necessary sizes only. The reasons of orders of MTM production were answered as 'no size available', 'unique body shape', etc., and most orders were placed by consumers who are fat-bellied or have thick thighs. They have used MTM automated CAD software developed by Gerber Technology or Investronica. All the brands have utilized automated marker-making software and cutting facilities for MTM production.

A Heuristic Algorithm for a Ship Speed and Bunkering Decision Problem (선박속력 및 급유결정 문제에 대한 휴리스틱 알고리즘)

  • Kim, Hwa-Joong;Kim, Jae-Gon
    • Journal of the Society of Korea Industrial and Systems Engineering
    • /
    • v.39 no.2
    • /
    • pp.19-27
    • /
    • 2016
  • Maritime transport is now regarded as one of the main contributors to global climate change by virtue of its $CO_2$ emissions. Meanwhile, slow steaming, i.e., slower ship speed, has become a common practice in the maritime industry so as to lower $CO_2$ emissions and reduce bunker fuel consumption. The practice raised various operational decision issues in terms of shipping companies: how much ship speed is, how much to bunker the fuel, and at which port to bunker. In this context, this study addresses an operation problem in a shipping companies, which is the problem of determining the ship speed, bunkering ports, and bunkering amount at the ports over a given ship route to minimize the bunker fuel and ship time costs as well as the carbon tax which is a regulatory measure aiming at reducing $CO_2$ emissions. The ship time cost is included in the problem because slow steaming increases transit times, which implies increased in-transit inventory costs in terms of shippers. We formulate the problem as a nonlinear lot-sizing model and suggest a Lagrangian heuristic to solve the problem. The performance of the heuristic algorithm is evaluated using the data obtained from reliable sources. Although the problem is an operational problem, the heuristic algorithm is used to address various strategic issues facing shipping companies, including the effects of bunker prices, carbon taxes, and ship time costs on the ship speed, bunkering amount and number of bunkering ports. For this, we conduct sensitivity analyses of these factors and finally discuss study findings.

Comparative Study of Approximate Optimization Techniques in CAE-Based Structural Design (구조 최적설계를 위한 다양한 근사 최적화기법의 적용 및 비교에 관한 연구)

  • Song, Chang-Yong;Lee, Jong-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.34 no.11
    • /
    • pp.1603-1611
    • /
    • 2010
  • The comparative study of regression-model-based approximate optimization techniques used in the strength design of an automotive knuckle component that will be under bump and brake loading conditions is carried out. The design problem is formulated such that the cross-sectional sizing variables are determined by minimizing the weight of the knuckle component that is subjected to stresses, deformations, and vibration frequency constraints. The techniques used in the comparative study are sequential approximate optimization (SAO), sequential two-point diagonal quadratic approximate optimization (STDQAO), and approximate optimization based on enhanced moving least squares method (MLSM), such as CF (constraint feasible)-MLSM and Post-MLSM. Commercial process integration and design optimization (PIDO) tools are utilized for the application of SAO and STDQAO. The enhanced MLSM-based approximate optimization techniques are newly developed to ensure constraint feasibility. The results of the approximate optimization techniques are compared with those of actual non-approximate optimization to evaluate their numerical performances.

Heat Exchanger Ranking Program Using Genetic Algorithm and ε-NTU Method for Optimal Design (유전알고리즘과 ε-NTU 모델을 이용한 다양한 열교환기의 최적설계 및 성능해석)

  • Lee, Soon Ho;Kim, Minsung;Ha, Man Yeong;Park, Sang-Hu;Min, June Kee
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.38 no.11
    • /
    • pp.925-933
    • /
    • 2014
  • Today, computational fluid dynamics (CFD) is widely used in industry because of the availability of high-performance computers. However, full-scale analysis poses problems owing to the limited resources and time. In this study, the performance and optimal size of a heat exchanger were calculated using the effectiveness-number of transfer units (${\varepsilon}-NTU$) method and a database of characteristics heat exchanger. Information about the geometry and performance of various heat exchangers is collected, and the performance of the heat exchanger is calculated under the given operating conditions. To determine the optimal size of the heat exchanger, a Genetic Algorithm (GA) is used, and MATLAB and REFPROP are used for the calculation.