• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1775-1780
• /
• 2003

A hybrid finite element analysis was used to analyze the influence of ring gear rim thickness and spline number on the static properties of an epicyclic gear system with manufacturing errors. Both of these parameters affected the bearing force and critical stress. The effect of changes in the rim thickness on the load sharing between the gears depended on the type of manufacturing error. Ring flexibility improved the load sharing between planetary gears only in systems with planet tooth thickness or planet tangential errors; for other types of error, ring flexibility worsened the load sharing. To improve load sharing, rim thickness and spline number should be controlled within a specific range. The effect of the ring gear boundary condition was more apparent in a system with errors than in a normal system.

• Industrial Engineering and Management Systems
• /
• v.11 no.2
• /
• pp.155-164
• /
• 2012

As the global market becomes more competitive, manufacturing industries face relentless pressure caused by a growing tendency of greater varieties of products, shorter manufacturing cycles and more sophisticated customer requirements. Efficient and effective supplier selection and order allocation decisions are, therefore, important decisions for a manufacturer to ensure stable material flows in a highly competitive supply chain, in particular, when customers are willing to accept products with less desirable product attributes (e.g., color, delivery date) for economic reasons. This paper attempts to solve optimally the challenging problem of supplier selection and order allocation, taking into consideration the customer flexibility for a manufacturer producing multi-products to satisfy the customers' demands in a multi period planning horizon. A new mixed integer programming model is developed to describe the behavior of the supply chain. The objective is to maximize the manufacturer's total profit subject to various operating constraints of the supply chain. Due to the complexity and non-deterministic polynomial-time (NP)-hard nature of the problem, an improved genetic approach is proposed to solve the problem optimally. This approach differs from a canonical genetic algorithm in three aspects: a new selection method to reduce the chance of premature convergence and two problem-specific repair heuristics to guarantee feasibility of the solutions. The results of applying the proposed approach to solve a set of randomly generated test problems clearly demonstrate its excellent performance. When compared with applying the canonical genetic algorithm to locate optimal solutions, the average improvement in the solution quality amounts to as high as ten percent.

• Journal of Korean Institute of Industrial Engineers
• /
• v.15 no.1
• /
• pp.23-30
• /
• 1989

The routing flexibility in FMSs can be achieved through two levels : the parallel operations and the alternative stations. To accommodate this pertaining flexibility for part routing in FMSs, a hierarchical routing principle is developed which considers both the routing flexibility and the performance effectiveness, which can also be easily implemented. For the proper implementation of this routing algorithm, the required information flow is identified which turns out to be very simple.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.10a
• /
• pp.229-244
• /
• 2004

This study addresses the problem of flexible technology acquisition in multi-product market when demands are uncertain. We confine the concept of flexibility to the ability of manufacturing system to produce a number of different types of products, called product-mix flexibility type. And an analytical model in which economies of scope is incorporated explicitly as a feature of flexible technology is presented to find the optimal investment decision to acquire flexible technology and optimal production planning. The characteristics of optimal investment strategy related to capacity and production planning are discussed.

• Journal of Korean Institute of Industrial Engineers
• /
• v.31 no.2
• /
• pp.135-142
• /
• 2005

This study addresses the problem of flexible technology acquisition in a multi-product market when demands are uncertain. We confine the concept of flexibility to the ability of manufacturing system to produce a number of different types of products, called a product-mix flexibility type. And an analytical model in which the economies of scope are incorporated explicitly as a feature of flexible technology is presented to find the optimal investment decision to acquire flexible technology and optimal production planning. The characteristics of optimal investment strategy related to capacity and production planning are discussed.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.18 no.35
• /
• pp.157-164
• /
• 1995

FMS(Flexible Manufacturing System) is an automatic manufacturing system coincided with pursue of flexibility, productivity, and reliability. It is effective means to prove tje needs of market changes in view of production, This study is carried out to provide a economical evaluation methods of introduction for FMS in domestic corporations using PB, ARR, NPV and IRR.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.11
• /
• pp.1949-1957
• /
• 2003

A hybrid finite element analysis was used to analyze the influence of ring gear rim thickness and spline number on the static properties of a planetary gear system with manufacturing errors. Both of these parameters affected the bearing force and critical stress. The effect of changes in the rim thickness on the load sharing between the gears depended on the type of manufacturing error. Ring flexibility improved the load sharing between planetary gears only in systems with planet tooth thickness or planet tangential errors; for other types of error, ring flexibility worsened the load sharing. To improve load sharing, rim thickness and spline number should be controlled within a specific range. The minimum rim thickness limit should be determined considering not only the critical stress but also the load sharing. The effect of the ring gear boundary condition was more apparent in a system with errors than in a normal system.

• Journal of Technology Innovation
• /
• v.3 no.1
• /
• pp.213-236
• /
• 1995

Advanced Manufacturing Technology(AMT), a comprehensive collection of new technologies for the efficiency and flexibility of manufacturing systems has received a growing attention recently, AMT consists of various industrial and technological components, homogeneous in some aspects while heterogeneous in others. Thus, it is difficult but necessary task to construct a classification framework in which the relationship among individual technologies are depicted in a meaningful fashion. In this, paper, we propose a hierarchical framework in which the objective and criteria of classification are decomposed into three level: industrialization, development and application of AMT. At the first and highest level, the main interest is to "industrialize" AMT. The major actors at this level are policy makers(public sector) and top management(private sector) and the primary classification criterion is the interrelationship between industry and technology. At the middle level exist system engineers whose main objective is to "develop" new technologies and/or systematize individual technologies. At the final and bottom level, shop floor managers need to "apply" AMT in order to enhance the efficiency and flexibility of manufacturing process. It should be stressed that, as a whole, the above three levels should be interactively linked to that each level contributes to the balanced development of AMT.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.6
• /
• pp.724-733
• /
• 1999

An effective method of system modeling and dynamic scheduling for the back-end line of semiconductor manufacturing is proposed. The virtual factory, describing semiconductor manufacturing line, is designed in detail, and then a Petri net model simulator is developed for operation and control of the modular cells of the virtual factory. The petri net model is a colored timed Petri nets (CTPNs). The simulator will be utilized to analyze and evaluate various dynamic status and operatons of manufacturing environments. The dynamic schedulaer has a hierarchical structure with the higher for planning level and the lower for dynamic scheduling level. The genetic algorithm is applied to extract optimal conditions of the scheduling algorithm. The proposed dynamic scheduling is able to realize the semiconductor manufacturing environments for the diversity of products, the variety of orders by many customers, the flexibility of order change by changing market conditions, the complexity of manufacturing processes, and the uncertainty of manufacturing resources. The proposed method of dynamic scheduling is more effective and useful in dealing with such recent pressing requirements including on-time delivery, quick response, and flexibility.

• Management & Information Systems Review
• /
• v.4
• /
• pp.225-255
• /
• 2000

The basic purpose of this research is to analyse a relationship between the integration level of AMT(ILAMT) and manufacturing performance (cost, quality, flexibility, delivery) and to identify the moderating effects of organizational structure in the relationship. First research question(hypothesis 1) was to examine the relationship between ILAMT and manufacturing performance. We tested this question using simple regression analysis. All of the correlation were positive and significant at the level of 1%(two-tail test). Therefore, hypothesis 1 was supported by the results. It means that firms that have high ILAMT are to exhibit high level of all manufacturing performance(cost, flexibility, quality, delivery). Namely, It is that the integration of AMT can solve the trade-off among manufacturing performance. Second research question (hypothesis 2) was to identify the moderating effects of organizational structure on the relationship between ILAMT and manufacturing performance. we tested this question using moderated regression analysis. According to the results, hypothesis 2 was partially supported. In other words, formalization and decentralization were accepted, but complexity was rejected. It means that firms with high ILAMT and an organic organizational structure are more likely to exhibit high level of manufacturing performance. To the practitioners, this research provided the answer to what they ought to do make AMT work in their organizations. To increase the effectiveness of AMT, first of all, they should take notice of the importance of integrated use of AMT, and the implementation of AMT should take into consideration the characteristics of organizational structure manufacturing strategy so that the effect of AMT may be multiplied by using AMT.