• 한국의류산업학회지
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• 제19권5호
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• pp.595-601
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• 2017

Advances in 3D garment simulation technology contribute greatly to consumers becoming more immersed in movies and games by realistically expressing the garments the characters in the movie or game are wearing. The fashion industry has reached a point where it needs to maximize efficiency in production and distribution to go beyond time and space in order to compete on the global market. The processes of design and product development in the fashion industry require countless hours of work and consume vast resources in terms of materials and energy to repeat sample production and assessment. Therefore, the design and product development tools and techniques must aim to reduce the sample making process. Therefore, this study aims to study a case for comparing the real garment sample making process to the virtual garment sample making process. In this study, we have analysed the differences between the real and virtual garment making processes by choosing designated patterns. As we can see from the study results, the real and virtual garments generally are made through similar processes in manufacturing, while the time consumed for each shows great variation. In real garment making, scissoring and sewing require the greatest number of work hours, whereas in virtual garment making, most of the time was spent in the simulation process.

• 지능정보연구
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• 제6권2호
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• pp.29-40
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• 2000

Process planning (selection and ordering of processes) and material selection for product manufacturing are two key things determined before taking full-scale manufacturing. Knowledge on product design. material characteristics, processes, time and cost all-together are mutually related and should be considered concurrently. Due to the complexity of problem, human experts have got only one of the feasilbe solutions with their field knowledge and experiences. We propose a hierarchical expert system framework of knowledge representation and reasoning in order to overcome the complexity. Manufacturing processes have inherently hierarchical relationships, from top level processes to bottom level operation processes. Process plan of one level is posted in process blackboard and used for lower level process planning. Process information on blackboard is also used to adjust the process plan in order to resolve the dead-end or inconsistency situation during reasoning. Decision variables for process, material, tool, time and cost are represented as object frames, and their relationships are represented as constraints and rules. Constraints are for relationship among variables such as compatibility, numerical inequality etc. Rules are for causal relationships among variables to reflect human expert\`s knowledge such as process precedence. CRSP(Constraint and Rule Satisfaction Problem) approach is adopted in order to obtain solution to satisfy both constraints and rules. The trade-off procedure gives user chances to see the impact of change of important variables such as material, cost, time and helps to determine the preferred solution. We developed the prototype system using visual C++ MFC, UNIK, and UNlK-CRSP on PC.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.636-639
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• 2002

In the paper, a Visual factory model for a optical-components manufacturing process is built. The optical-components manufacturing process is composed of 3 operation processes; optical sub assembly process, package assembly process, and fiber assembly process. Each process is managed not a batch mode, which is one of most popular manufacturing styles to produce a great deal of industrial output, but though a modular cell. In the processes, a modular cell has to be processed independently of the other cells. Optimization for the composition of assembly cell in the optical-components system is made by the Visual factory model.

• 산업공학
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• 제23권3호
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• pp.205-212
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• 2010

The learning curve model is a mathematical form which represents the relationship between the manufacturing experience and its effectiveness. The semiconductor manufacturing is widely known as an appropriate example for the learning effect due to its complicated manufacturing processes. In this paper, I propose a new compound learning curve model for semiconductor products in which the general learning curve model and the growth curve are composed. The dependent variable and the effective independent variables of the model were abstracted from the existing learning curve models and selected according to multiple regression processes. The simulation results using the historical DRAM data show that the proposed compound learning curve model is one of adequate models for describing learning effect of semiconductor products.

• 대한안전경영과학회지
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• 제12권1호
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• pp.71-81
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• 2010

Today's fierce competition and global economic recession make most of manufacturing companies in the world difficult to gain a profit. In order to survive such a environment and increase competitiveness, manufacturing companies have to continuously eliminate their wasteful factors through an efficient process analysis, improve quality of products, increase the flexibility of manufacturing processes. In this paper, we consider a case study for the Shanghai New Auto which is a subcontractor of MOBIS in China, to improve productivity by using therblig method, one of the motion analysis, to minimize the work-in-process inventories and to shorten the manufacturing cycle times. We also try to relocate the facility layout to increase the efficiency and flexibility of manufacturing processes.

• 한국생산제조학회지
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• 제19권1호
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• pp.94-100
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• 2010

Nowadays, several nontraditional machining(NTM) processes are widely used to machine a complex and accurate shape part of hard materials, such as titanium, ceramics, high strength temperature resistant and refractory materials which are difficult to machine and having high strength, hardness, toughness. Machining of these complex shapes in such materials by traditional machining processes are very difficult. The NTM processes is important in the areas of micro- and nano scale machining, where high accuracy and superior surface characteristics are required, which can only be achieved using these NTM processes. So, for effective selection of different NTM processes, careful decision making for a given NTM application is often necessary. An appropriate NTM process for a given material and shape condition is very difficult for the novice engineers. In this paper, an expert system based on an analytic network process(ANP) is suggested for a best selection of NTM process in a NTM application considering an prior interdependency effect among various factors.

• 한국정밀공학회지
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• 제31권11호
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• pp.969-974
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• 2014

Previously fabricated electronic devices were used for vacuum manufacturing processes such as conventional semiconductor manufacturing. However, they are difficult to apply to continuous processes such as roll-to-roll printing, which results in very high device manufacturing and processing costs. Therefore, many developers have been interested in applying continuous processes to contact printing or noncontact printing technologies and they proposed various continuous printing techniques instead of conventional batch coating. In this paper, we proposed improved gravure offset printing process as one of the contact printing technique. We used etching pattern geometry with soft core blanket roll for printing of ultra fine line below the 10um.Using this technique we obtained flexible metal grid mesh film as transparent conductive film.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2000년도 춘계학술대회
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• pp.225-239
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• 2000

The objective of ECMS(Environmentally Conscious Manufacturing Systems) is to consider environmental effects through the entire product life cycle from product development stage to design, manufacturing, supplying, using and disposing stage. Recently, environment-oriented recycling, reusing and manufacturing technologies have been researched actively in every engineering fields. In the field of chemical engineering, HHS(Health Hazard Scores) which classifies and analyzes hazardous materials in production processes has been presented. Metal cutting processes also have a lot of harmful factors, and especially hazardous components in cutting fluids have been known to have a bad effect on workers and working area. However, research works such as HHS have been little accomplished in metal cutting processes. In this research, a environmentally conscious machining process is presented by classifying hazardous components in cutting fluids, by using LCA(Life Cycle Assessments) and HHS method, and by evaluating environmental effects from cutting fluids.

• 한국기계가공학회지
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• 제14권4호
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• pp.14-20
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• 2015

Molding technologies for plastic microstructures have been extensively investigated during the last two decades, and theoretical and numerical studies on the micro molding process have provided efficient tools for the development of such molding technologies. In this paper, we present a review of numerical simulation methods for the micro molding process. Basic models for a description of the material property, governing equations of the flow and heat transfer during the molding process, and numerical methods will be described. Particularly, numerical simulations for micro injection molding and hot embossing processes will be presented, and their main features noted and compared to those for conventional molding processes.

• 품질경영학회지
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• 제22권4호
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• pp.79-101
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• 1994

In modern manufacturing, a product consists of many components created by different processes. Variations in the individual component dimensions and in the processes may result in unacceptable final assemblies. Thus, engineers have increased pressure to properly set tolerance specifications for individual components and to control manufacturing processes. When a proper variation stack-up analysis is not performed for all of the components in a functional system, all component parts can be within specifications, but the final assembly may not be functional. Thus, in order to improve the performance of the final assembly, a proper variation stack-up analysis is essential for specifying dimensional tolerances and process control. This research provides a detailed case example of the use of variation stack-up analysis using a Monte Carlo simulation method to improve the defect rate of a complex process, which is the commutator brush track undercut process of an armature assembly of a small motor. Variations in individual component dimensions and process mean shifts cause high defect rate, Since some dimensional characteristics have non-normal distributions and the stack-up function is non-linear, the Monte Carlo simulation method is used.