• Journal of the Korean Operations Research and Management Science Society
• /
• v.28 no.3
• /
• pp.67-79
• /
• 2003

An efficient mobility management for mobile stations plays an important role in mobile communication networks. Even though many a mobility management schemes have been proposed, most of mobile communication networks adopt the mobility scheme based on zone-based registration. This paper studies the mobility management scheme that combines zone-based registration and 2-step selective paging. We assume cell by cell registration area, not ring by ring registration area of previous studies, and set up a new mobility model based on 2-dimensional random walk model considering the characteristic of zone-based registration to evaluate its performance exactly. We provide numerical results using proposed model to demonstrate the performance of zone-based registration and 2-step selective paging under various circumstances.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1991.10a
• /
• pp.51-65
• /
• 1991

This paper describes computer-integrated manufacturing (CIM) systems as strategic information systems for business which play an important role in accelerating the speed of business, and develops a measure showing a degree of business tendency to be CIM which enables the business to check on its present status as far as CIM is concerned. It is well known that the productivity of knowledge workers is lower than that of other workers. Nowadays, a great deal of effort goes into the productivity improvement of knowledge workers. In this respect, this paper also develops a quantitative model for the productivity of knowledge workers. Finally, this paper deals with following four steps which our small business should follow through its process of CIM: [Step 1] Using expert knowledge; [Step 2] Invention of technological information; [Step 3] Feedback of factory information to the management; and, [Step 4] Accelerating the speed of business.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2006.05a
• /
• pp.1342-1349
• /
• 2006

오늘날의 제품개발환경은 분산환경에 존재하는 다양한 역량을 가진 참여자들의 협업을 요구하고 있으며, 협업은 참여자들이 필요로 하는 제품개발관련 정보들의 실시간 교환을 지원할 수 있도록 제품정보 간 상호운용성 확보를 기반으로 한다. STEP으로 알려진 ISO 10303은 제품개발의 전체적인 라이프사이클에서 필요한 제품정보의 표현과 공유 및 교환을 위한 대표적인 표준이다. 하지만 STEP을 이용하기 위해서는 각 도메인이 표준인 STEP 모델에 기반하여 제품정보를 모델링 하여야 한다. 그러나 대부분의 도메인은 자신의 목적에 따라 특화된 모델을 정의하고 사용하기 때문에 도메인에 특화된 형태의 제품정보모델을 STEP 모델로 변환할 수 있는 추가적인 메커니즘이 필요하다. 즉, STEP은 참조모델보다는 모든 도메인에서 제품정보모델링을 위해 사용가능한 표준의 정의에 초점을 맞춘다. 그러므로 참조모델로서의 STEP을 기반으로 다양한 도메인 특화된 제품정보모델 간 상호운용성 확보를 지원하기 위하여 본 논문에서는 STEP 제품정보모델의 시맨틱스를 체계적으로 정의할 수 있도록 온톨로지 구축을 통한 컨셉추얼 모델링을 수행한다. 컨셉추얼 모델링은 STEP 모델에 정확하고 완전한 의미를 부여하여, 다양한 도메인 특화된 모델 사이의 상호운용성 확보를 지원하고 참조모델로서 STEP의 능력을 확장한다.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2001.10a
• /
• pp.286-289
• /
• 2001

This paper deals with the procedures of effective mid-term Operation Planning establishment for painting shop in shipbuilding. and develop prototype system. In general, the block painting process consists of two stages such as blasting operation for surface preparation and painting operation for paint application for blocks. Weather condition is a potent Influence on those operations. The procedures consists of four steps, Load analysis, Generate alternative simulation plan. Implementation of Allocation automation module and Compare result of each simulation plan. Explain of each step. as follows, 1.step, Load analysis measure amount of assigned workload and manhour. 2.step, simulation scheme include alterable control variable such as overtime, weather. Auto allocating module carry out feasibility of simulation plan. 3.step, Allocation automation module are composed of three algorithms, as followings: - the block allocation algorithm that determines the number of blocks to be processed each day, - the team allocation algorithm that allocates blocks to worker groups. - the block arrangement algorithm that arrange blocks in blasting and painting cells. Since the block arrangement algorithm is conducted simultaneously with the team allocation algorithm, the total structure of the operating algorithms is considered to have two phases: first, daily load balancing with capacity limit and second, team allocation considering arrangement each day 4 step, Comparing result of each simulation plan. and select best simulation plan.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.19 no.1
• /
• pp.113-122
• /
• 1994

This study proposes a new procedure to find an initial solution to reduce the number of iterations of goal programming. The process of computing an initial solution is divided into two steps in this study. Decision variables which satisfy feasibility using Gaussian eliminations construct an initial solution reducing the iterations in the first step. It uses LHS as a tool that decision variables construct an initial solution. The initial solution which is constructed by the first step computes the updated coefficient of the objective function in the second step. If the solution does not satisfy the optimality, the optimal solution using the Modified Simplex Method is sought. The developed method doesn't reduce the overall computing time of goal programming problems, because time is more required for the process of constructing an initial solution. But The result of this study shows that the proposed procedure can reduce the large number of iterations in the first step effectively.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2003.05a
• /
• pp.217-224
• /
• 2003

ISO 14649 is a new interface (or language) standard for the CAD-CAM -CNC chain, currently under establishment by ISO TC184 SCI and SC4 . Upon completion, it will replace ISO 6983, so called M amp; G codes used for CNC since 1950' s. As the new language is being established, a new CNC controller called STEP-CNC (STEP­compliant CNC), capable of carrying out various intelligent tasks using the new language as an input, receives worldwide attention. In this paper, we present a distributed architecture for STEP-NC system based on the generic paradigm of STEP-NC. The STEP-NC system is consisted of 3 sub-systems: 1) CGS (Code Generation System), 2) CES (Code Edit System), and 3) ACS (Autonomous Control System). Also presented in this paper is algorithm for delta volume decomposition, a crucial algorithm for developing CGS. First method is based on the cutting tool and the second method is based on the turning features commonly used in the shop floor. An illustrative example is given to compare the two methods, and to illustrate usage scenario of the delta volume in the turning STEP- NC system under development.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1996.04a
• /
• pp.310-313
• /
• 1996

Mathematical programming method for finding optimal solution of job shop scheduling is inadequate to real situation because fo too much computation time. In contrast, dispatching rule is helpful for reducing compuation time but is not guaranted to find optimal solution. The purpose of this paper is to develop a new dispatching rule and procedure to minimize mean flow time whose result is near the optimal solution for job shop scheduling. First step is to select machine which have shortest finishing operation time among the schedulable operations. Second step is to select operation with regard to estimated remaining operation time. The suggested rule is compared with nondelay and MWKR rule for three examples, and is confirmed to be most effective to minimize mean flow time.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1990.04a
• /
• pp.49-60
• /
• 1990

Structured modeling provides a formal mathematical framework, language, and computer-based environment for conceiving, representing, and manipulating a wide variety of models. It provides a natural framework for integrated modeling owing to its explicit representation power for computational dependencies among submodels. Nevertheless, it doesn't seem to offer a systematic way of composing a structured model from submodels. In order to develop a systematic way, this paper discusses three key issues; (1) Genus structure of validated submodel, (2) Storing method of genus structure, and (3) Integration of genus structures to generate a new genus structure. To visualize the approach, a programming module is developed to implement the step-by-step integration.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.05a
• /
• pp.405-408
• /
• 2004

This paper describes an architecture information management system using XML. The purpose of the system is to manage the information stored in standard format, XML, that has many valuable properties. The proposed architecture information consists of project information, drawing information, and material information. Each information is expressed using XML and for each information, XML schema is presented in this paper. In this system, detail information of materials that exists on the supplier's homepage can be displayed when the user of the system wants to check the detail information. Also, drawings stored in STEP data can be browsed in this system. The reports of each information are prepared using XSL. The proposed system shows that XML can be used for a format to store architecture information and various functions can be implemented based on XML related standards.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.05a
• /
• pp.658-663
• /
• 2005

This study presents the empirical results of comparing several demand forecasting methods for Supply Chain Management(SCM). Adaptive exponential smoothing using change detection statistics (Jun) is compared with Trigg and Leach's adaptive methods and SAS time series forecasting systems using weekly SCM demand data. The results show that Jun's method is superior to others in terms of one-step-ahead forecast error and eight-step-ahead forecast error. Based on the results, we conclude that the forecasting performance of SCM solution can be improved by the proposed adaptive forecasting method.