• Journal of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.64-72
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• 1995

Sizing design sensitivity analysis of structures subjected to the harmonic vibration is performed using adjoint variable method. Constraint is the stress and sizing design variables are thickness, bending moment of inertia, and cross-sectional area of structures. Accurate sensitivities are computed and plotted sensitivity can be used as a design guidance tool. The accuracy of sensitivities is verified by the finite difference values. Also, optimal design of three-bar structure is performed using the computed sensitivity and feasible direction method while satisfying constraints and obtaining the minimum weight.

• Journal of the Ergonomics Society of Korea
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• v.13 no.1
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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.

• Korean Journal of Human Ecology
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• v.12 no.4
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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.

• Transactions of Materials Processing
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• v.17 no.8
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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.

• Journal of the Korean Home Economics Association
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• v.40 no.7
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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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• v.54 no.6
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.2955-2963
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• 2012

This study presents a column generation approach for multiple product dynamic lot-sizing problem. The basic idea of this approach is to have a master problem which allocates limited capacity among n different products and a sub-problem that performs the optimal lot sizing for each product subject to capacity allocation given by the master problem. In the sub-problem, we develop M/G/1 queuing model based clearing function which captures nonlinear relationship between the lot size, the work in process level and the throughput. A large number of test problems are randomly generated to evaluate the performance. Computational results show that the proposed model can find better solutions within reasonable CPU times.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.3
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• pp.307-312
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• 2013

The interest in reducing the emissions and increasing the fuel economy of ICE vehicles has prompted research on hybrid vehicles, which come in the series, parallel, and power-split types. This study focuses on the series-type hybrid electric vehicle, which has a simple structure. Because each component of a series hybrid vehicle is larger than the corresponding component of the parallel type, the sizing of the vehicle is very important. This is because the performance may be greater or less than what is required. Thus, in this research, the optimal fuel economy was determined and simulated in a real-world system. The optimal sizing was achieved based on the motor, engine/generator, and battery for 13 cycles, where DP was used. The model was developed using ASCET or a Simulink-Amisim Co-simulation platform on the rapid controller prototype, ES-1000.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.10
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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.