• Structural Engineering and Mechanics
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• 제83권3호
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• pp.341-351
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• 2022

During bolted flange assembly, the contact stiffness of some areas of the joint surface may be low due to the elastic interaction. In order to improve the contact stiffness at the lowest position of bolted flange, the correlation model between the initial bolt pre-tightening force and the contact stiffness of bolted flange is established in this paper. According to the stress distribution model of a single bolt, an assumption of uniform local contact stiffness of bolted flange is made. Moreover, the joint surface is divided into the compressive stress region and the elastic interaction region. Based on the fractal contact theory, the relationship model of contact stiffness and contact force of the joint surface is proposed. Considering the elastic interaction coefficient method, the correlation model of the initial bolt pre-tightening force and the contact stiffness of bolted flange is established. This model can be employed to reverse determine the tightening strategy of the bolt group according to working conditions. As a result, this provides a new idea for the digital design of tightening strategy of bolt group for contact stiffness of bolted flange. The tightening strategy of the bolted flange is optimized by using the correlation model of initial bolt pre-tightening force and the contact stiffness of bolted flange. After optimization, the average contact stiffness of the joint surface increased by 5%, and the minimum contact stiffness increased by 6%.

• 한국컴퓨터정보학회논문지
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• 제15권2호
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• pp.179-187
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• 2010

본 연구는 제품구조의 관점으로부터 접근하여 우리나라의 전자산업 및 자동차산업에 대한 경쟁력 제고 방안을 모색하고자 한다. 제품구조는 Modular(짜맞추기)형과 Integral(현장맞춤)형의 두 가지로 분류된다. 부품 간 특성으로서는 서브시스템 간의 독립성이 높은 것이 Modular형이고, 서브시스템 간에 높은 상호의존성이 있는 것이 Integral형이다. 제품구조의 차이에 의해서 그것에 적합한 상품개발의 조직능력이 다르다. 상품개발의 조직능력에는 크게 나누어서 '통합 현장맞춤 능력'과 '선택 짜맞추기 능력'이 있다. 자동차와 같은 Integral형 제품에는 부품 간이나 기업 간에서 현장맞춤 능력이 중요하며, PC와 같은 Modular형 제품에는 최적의 부품이나 기업을 선택하여 효과적으로 그것들을 짜맞추는 능력이 필요하다. 제품구조에 관한 '설계 제조전략'과 고객가치에 관한 '고객가치전략'을 통합함으로써 상품의 경쟁력 제고 전략을 추구한다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 춘계학술대회 논문집
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• pp.102-106
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• 1997

Grinding has difficulty in satisfying the qualitative knowledge based on the skilled expert as well as quantitative data for all user. Design of grinding database is based on the frame-based model for utilizing the empirical and qualitative knowledge. Inthis paper, basic strategy to develop the grinding database by frame-based model, which is strongly dependent upon experience and intuition, frame-base model, which is strongly dependent upon experience and intuition, is described. Design of grinding database is based on the frame-based model for utilizing the ambiguous knowledge and inference is accomplised by the object-oriented paradigm system.

• 한국정밀공학회지
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• 제17권6호
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• pp.127-134
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• 2000

The current three-stage cold farming process to produce a flange is investigated for the purpose of improvement of manufacturing process. The main goal of this study is to obtain an appropriate process sequence, which can produce the required part with less manufacturing cost. The current process sequence is simulated using finite element method and design criteria are examined. Based on the results of simulation of the current three-stage process. a design strategy for improving the process sequence is analyzed using the thick-walled pipes. Because it has a reduced process-sequence without buckling of the workpiece or overloading of tools, the new process has distinct advantages over the conventional process. Numerical results show that the newly proposed process with selected presses is the most economical way to produce the required part.

• 한국CDE학회논문집
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• 제18권2호
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• pp.120-128
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• 2013

Recently, the importance of the HVAC system (Heating, Ventilating and Air Conditioning System) is growing because comfortable working environment has emerged as important element for enhancing work efficiency. HVAC system is a general term of a system that collectively creates desired temperature and state through heating and air conditioning. HVAC system consists of many objects, so it requires a lot of constraints for its effective operation. Thus, specific strategy is needed for an optimal operation of HVAC System for plant. In this paper, manufacturing plants which have HVAC systems has been modeled and the objective function and constraints for an effective operation have been defined. And new strategy for an effective operation of HVAC system with energy simulations has been proposed.

• 산업경영시스템학회지
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• 제22권50호
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• pp.45-54
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• 1999

Cellular manufacturing(CM) is a manufacturing philosophy and strategy for improving both productivity and flexibility. Cell formation(CF), the first and key problem faced in designing an effective CM system, is a process whereby parts with similar design features or processing requirements are grouped into part families, and the corresponding machines into machine cells. In this paper, a sophisticated fuzzy mixed-integer programming model is proposed to simultaneously form manufacturing cells and minimize the total costs of dealing with exceptional elements. Also, we will proposed a new method to solve the cell formation problem in the fuzzy environment.

• 대한안전경영과학회지
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• 제4권1호
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• pp.105-114
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• 2002

Nowadays, most companies seek after the greatest profit by means of offering the goods which consumers want timely and efficiently and minimizing the cost of inventory and distribution channel which amounts to the great portion of total cost. And according as EC(Electronic Commerce) market has increased rapidly, SCM(Supply Chain Management) for EC become one of the most important facts for companies, therefore this paper suggest SCM scheme which EC, especially B to C, is added to the existing commerce system. This paper uses internet for information integration of distribution channel which is away from one another and applies TOC(Theory of Constraint)'s DBR(Drum-Buffer-Rope) Scheduling for synchronization through the whole supply chain. It is possible to synchronize the whole supply chain by means of making the speed of manufacturing and distribution to be controlled by consumer's order which is received in distribution center, and inventory and loss of sales opportunities are minimized by constant. Buffer Management. If inventories in distribution center is short, then it needs to search CCR(Capacity Constraint Resource) in supply chain and to control the speed of manufacturing and distribution according to the ability of CCR. This paper applies PT(Partial Transshipment) strategy for Delivery from distribution center to store or cyber consumer. the strategy this paper suggests chooses neighbour area from area which each distribution center takes charge, and then makes product ordered by cyber consumer which lives in the chosen area to be delivered according to inventory of distribution center.

• 유통과학연구
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• 제11권10호
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• pp.27-36
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• 2013

Purpose - This paper empirically studies the effects of advanced design innovation strategy on business performance, to investigate manufacturing industries that can develop design-driven-innovation strategies. Many researchers now recognize the importance of design in a CEO's decision-making process. To analyze these effects, this study deduces the definition of advanced design strategy by reviewing existing studies. The advanced design is a strategy that is applied to improve business performance instead of the appearance of a product for increasing its sales. In terms of business processes, the advanced design strategy is defined as the incorporation of business activities prior to the development of the product, to offer new experiences and values to users, from those designs. Research design/data/methodology - This paper establishes a model for empirical analysis. In this study, we derived factors of the characteristics of advanced design based on previous studies. We tried to investigate whether advanced design innovation strategy and entrepreneur's characteristics could have any impact on business performance. At the same time, we tried to find out the moderating effect of entrepreneurs' characteristics. The advanced design is made up of three elements: precedence, integration, and immersion of design activities. These three elements are independent variables for the model. The dependent variables are: increased rate of sales, R & D performance, and public image of the company. Specifically, this study establishes a CEO's characteristics as a moderating variable between the independent and dependent variables. Results - We proved that the level of entrepreneurs' characteristics has a moderating effect on the business performance. The findings of this study offer the following theoretical implications. The precedence of design activities positively affects the increased rate of sales by offering new experiences to users and creating new values. The integration of design activities also has a positive effect on the R&D performance. In addition, the immersion of design activities positively influences all the elements comprising business performance. The analysis of moderating variables elucidates that CEO's characteristics have a moderating role between precedence, integration, and immersion of design activities, and business performance. Conclusions - The practical implications of the study are as follows. This study contributes to the progression of advance design theories by conducting an empirical study on the advanced design concept. More importantly, the empirical study on the CEO group seeking exploratory innovation supports Verganti's "design-driven innovation" concept, according to which design can make innovation successful by offering useful values to users, as evident in the case of many innovative companies, such as Nintendo and Apple. Future studies need to investigate the reliability of practical examples, including the various activities of business. We suppose that there may be real differences between the results of this study and the applicative situation in the presence of a CEO group.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2987-2997
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• 2011

As a public transit playing an important role in the era of high gas prices, subway corresponds the national strategy 'Low carbon, Green growth'; accordingly, passengers who would use the transportation are steadily increasing. Subway operators are required to provide subway users with services based on higher-quality system, safety, convenience & high reliability level. Furthermore, as the legally allowed maximum life time of EMUs is extended, it is necessary to localize & standardize the parts of EMUs. This paper presents a modelling of systematic EMU(SR001) manufacturing technique which enables us to reflect passenger and subway operator's demands in the whole EMU manufacturing process from the initial design phase to its completion by making full use of the know-how based on subway operators' experiences. SR001 enabled SMRT's staffs to participate in the EMU design & its equipment manufacturing; consequently, it realized the innovative system which meets passengers' requirements. Moreover, the process lead time was reduced dramatically. The result of this research will be helpful in providing useful guidelines for railway industry policy and development making in Korea.

• 한국CDE학회논문집
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• 제14권4호
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• pp.242-253
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• 2009

Nowadays, manufacturing industry has been making its effort not only for productivity elevation but also for cost reduction in order to survive in the global market which is more and more challenging. In this paper, the method for planning of digital manufacturing system is proposed and door trim assembly system is determined as the subject of our research. First of all, the process sequence is generated based on the product analysis. And, the static and dynamic relationships between system components are represented using IDEF0 and UML model. The working time is estimated through the regression analysis based on MODAPTS method. According to the system configuration strategy, initial concept system layout is implemented 3D virtual environment. The problems caused by bad working motions are detected and modified through the ergonomic analysis using RULA method. According to proposed procedure, digital door trim assembly system is implemented in DLEMIA.