• 대한조선학회논문집
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• 제32권4호
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• pp.64-72
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• 1995

본 연구에서는 조화기진력이 작용하는 구조물에서 보조변수법을 사용하여 치수설계 민감도가 계산되었다. 제한함수는 구조물의 진동응력이고 설계변수는 막구조의 두께, 보구조의 굽힘관성모멘트, 봉구조의 응력이며 신뢰성있는 민감도값이 계산되었다. 민감도값의 크기와 방향이 plot되어 응력에 민감한 부분이 인지되고 정확도는 유한차분치와 비교되었으며, 또한 계산된 민감도가 사용되어 three-bar 구조물의 제한조건이 만족되고 중량이 최소화되는 최적설계가 수행되었다.

• 대한인간공학회지
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• 제13권1호
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• pp.59-74
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• 1994

The purposes of this paper were to suggest the procedures for a sizing sys- tem which can provide good fitting of apparel and minimize the loss due to excessive inventory, and to determine an adequate apparel sizing standard. An anthropometric database used for this study was the 1992 National Anthro- pometric Survey of Koreans. The database was limited to 1,336 women who were 18-51 years old. They study was conducted by classifying ages into two groups (18-33, 34-51) using Wilk's lamda. Three principal components : laterality( fullness), linearity(length) and characteristic of torso were selected to describe body types, and these three body type classification of each group were selected by cluster analysis. It was found that all intervals between standard sizes were not equal. They were narrow around the center with high frequencies of the customers but wide in both tail with low frequencies. It was also found that the optimal sizes suing the loss function can be applied well in practice.

• 한국생활과학회지
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• 제12권4호
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• pp.553-558
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• 2003

The purpose of this paper was to design the sizing system of the head gears which would be a guide of men for selecting their head gears of suitable size. This study was carried out on 214 men and was done by cluster analysis with two variables(head circumference and bitragus to vertex arc length). The results were as follows : First, most of measurements were larger in men than in women. Second, the suitable numbers of size were found that 5 sizes were proper by cluster analysis with two variables. After the design of sizing system, the cover ratio was investigated in order to decide whether it is proper or not. Third, in the cover ratio, the 5 sizes were the highest in all of them.

• 소성∙가공
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• 제17권8호
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• pp.619-626
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• 2008

In this study, design methodology to determine optimal shape of the anvil in sizing press process has been proposed to minimize crop length of the AISI 1010 slab in horizontal rolling after width reduction. Shape of anvil were selected to 12 cases by design of experiment, and the dog-bone shapes and the crop length were determined by FE-analysis. Also, the anvil shape, which has minimum crop length, were determined by artificial neural network(ANN). As a result of FE-analysis, it can be seen that the crop length was increased with increasing center thickness in the dog-bone shape after width reduction. The anvil shape which has minimum crop length, was estimated to ${\theta}_{1}=21^{\circ}{\theta}_{2}=14^{\circ}$ by FE-analysis and ANN.

• 대한가정학회지
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• 제40권7호
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• pp.157-172
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• 2002

The purpose of this study is to characterize body types of males in their twenties, and to provide information on body types of males by classifying them into groups. In addition, this study attempts to provide ways that can help improve the fit and coverage rate of ready-to-wear clothes by developing an apparel sizing system according to body types. 297 male subjects in their twenties participated in this study. 54 anthropometric and 35 photographic measurements were taken from each subject. After combining the body types of the front and the side into a whole body, we selected typical body types out of the combinations. It is shown that 84.64% of males in their twenties belong to the HI type, H/equation omitted/ type, X/equation omitted/ type, Xl type, Yl type, and HS type. To develop a new size system of clothes, the distribution of sizes was determined by using means and standard deviations for basic parts of each body type. Then, the most optimal sizes were selected separately for each body type to maximize the coverage rate.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2262-2275
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• 2022

The Korea Atomic Energy Research Institute (KAERI) studied the sodium-water reaction (SWR) minimized steam generator for the safety of the sodium-cooled fast reactor (SFR), and selected the copper bonded steam generator (CBSG) as the optimal concept. This paper introduces the conceptual design of the CBSG and the development of the CBSG sizing analyzer (CBSGSA). The CBSG consists of multiple heat transfer modules with a crossflow heat transfer configuration where sodium flows horizontally and water flows vertically. The heat transfer modules are stacked along a vertical direction to achieve the targeted large heat transfer capacity. The CBSGSA code was developed for the thermal-hydraulic analysis of the CBSG in a multi-pass crossflow heat transfer configuration. Finally, we conducted a preliminary sizing and rating analysis of the CBSG for the trans-uranium (TRU) core system using the CBSGSA code proposed by KAERI.

• 한국산학기술학회논문지
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• 제13권7호
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• pp.2955-2963
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• 2012

본 논문은 다품종 동적 로트사이징 문제를 풀기 위하여 열생성 기법에 기반한 알고리즘을 제안한다. 제안한 알고리즘의 기본 개념은 한정된 생산 용량을 주문제를 통하여 n개의 제품에 할당하고, 주문제에 의하여 할당된 생산용량을 기반으로 하여 각각의 제품에 대하여 최적화된 로트사이징 문제를 반복적으로 풀어나감으로써 해를 구해나가는 것이다. 부문제를 풀기 위해 본 논문은 로트사이즈, 재공재고 그리고 생산량 간에 존재하는 비선형관계를 기반으로 한 M/G/1모델 기반의 최적화 로트사이징 모델을 제안한다. 실험을 통하여 제안한 알고리즘이 비교적 짧은 시간안에 좋은 해를 생성함을 보여준다.

• 대한산업공학회지
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• 제33권2호
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• pp.246-253
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• 2007

All of the machines in a production line can be classified into bottleneck and non-bottleneck machines. A bottleneck is a resource whose capacity limits the throughput of the whole production facility. This paper addresses a batch sizing problem at the bottleneck machine. Traditionally, most batch sizing decisions have been made based on the EOQ (economic order quantity) model where setup and inventory costs are considered while throughput rate is assumed to be given. However, since batch size affects the capacity of the bottleneck machine, the throughput rate may not be constant. As the batch size increases, the frequency of the setup decreases. The saved setup time can be transferred to processing time, which results in higher throughput. But, the larger batch size may also result in longer lead time and larger WIP inventory level. This paper presents an alternative method to determine batch size at the bottleneck machine in a manufacturing line. A linear search algorithm is introduced to find optimal throughput rate and batch size at the same time. Numerical examples are provided to see how the proposed method works and to investigate the effects of some parameters.

• 대한기계학회논문집B
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• 제37권3호
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• pp.307-312
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• 2013

직렬형 하이브리드 자동차는 구조가 간단하고 단품들의 효율이 높기 때문에 연비성능이 우수하며, 병렬형과 비교하여 배터리, 엔진, 모터의 용량이 상대적으로 고용량인 특징을 가진다. 본 연구에서는 직렬형 하이브리드 자동차의 최적용량매칭을 통해 최적의 연비를 도출하고, 실시간 시뮬레이션 환경에서 사용될 알고리즘을 개발한다. 연구에서 진행된 용량매칭은 모터, 엔진/발전기 및 배터리를 대상으로 13개 주행 사이클에 대하여 순차적으로 이루어 졌으며, 이를 위해 Matlab 환경에서 최적화 기법인 DP(Dynamic Programming)을 사용하였다. 실시간 성능검증을 위한 차량모델은 Simulink 및 AMEsim을 기반으로 개발되었고 실시간 제어로직이 구현된 RCP(Rapid Control Proto-typing)와 연동하여 그 성능을 확인할 수 있었다.

• 제어로봇시스템학회논문지
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• 제7권10호
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• pp.867-873
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• 2001

The purpose of this study is to find analytic solution of determining the optimal capacity (lot-size) of multiproduct acyclic multistage production and inventory system to meet the finished product demand under the constraint of finite intermediate storage. Intermediate storage is a practical way to mitigate the material flow imbalance through the line of supply and demand chain. However, the cost of constructing and operating storage facilities is becoming substantial because of increasing land value, environmental and safety concern. Therefore, reasonable decision-making about the capacity of processes and storage units is an important subject for industries. The industrial solution for this subject is to use the classical economic lot sizing method, EOQ/EPQ(Economic Order Quantity/Economic Production Quantity) model, incorporated with practical experience. But EOQ/EPQ model is not suitable for the chemical plant design with highly interlinked processes and storage units because it is developed based on single product and single stage. This study overcomes the limitation of the classical lot sizing method. The superstructure of the plant consists of the network of serially and/or parallelly interlinked non-continuous processes and storage units. The processes transform a set of feedstock materials into another set of products with constant conversion factors. A novel production and inventory analysis method, PSW(Periodic Square Wave) model, is applied to describe the detail material flows among equipments. The objective function of this study is minimizing the total cost composed of setup and inventory holding cost. The advantage of PSW model comes from the fact that the model provides a set of simple analytic solutions in spite of realistic description of the material flows between processes and storage units. the resulting simple analytic solution can greatly enhance the proper and quick investment decision for the preliminary plant design problem confronted with economic situation.