• International Journal of Reliability and Applications
• /
• v.18 no.1
• /
• pp.9-20
• /
• 2017

In this paper, we consider a renewable repair-replacement warranty strategy with age-dependent minimal repair service and propose an optimal maintenance model during post-warranty period. Such model implements the repair time limit under warranty and follows with a certain form of system maintenance strategy when the warranty expires. The expected cost rate is investigated per unit time during the life period of the system as for the standard for optimality. Based on the cost design defined for each failure of the system, the expected cost rate is derived during the life period of the system, considering that a renewable minimal repair-replacement warranty strategy with the repair time limit is provided to the customer under warranty. When the warranty is finished, the maintenance of the system is the customer's responsibility. The life period of the system is defined and the expected cost rate is developed from the viewpoint of the customer's perspective. We obtain the optimal maintenance strategy during the maintenance period by minimizing such a cost rate after a warranty expires. Numerical examples using field data are shown to exemplify the application of the methodologies proposed in this paper.

• Structural Engineering and Mechanics
• /
• v.15 no.5
• /
• pp.551-562
• /
• 2003

This paper presents a procedure for designing feedback controllers for defective systems with repeated eigenvalues, and also for a nearly defective system with close eigenvalues. For the nearly defective system, we first transform it into a defective one, and then apply the same method to deal with the nearly defective system. A method for computing the gain matrices is discussed here. The methodologies proposed are based on the modal coordinate equation to avoid the tedious mathematical manipulation. As an application of the present procedure, a numerical example is given.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.281-285
• /
• 2008

The railroad roadbed plays an important role in distributing and transferring the train loading to subgrade, preventing subgrade from bearing softened by providing appropriate stiffness for subgrade, and eventually supporting the track structures. Presently, the reinforced roadbed was widely constructed in high speed line and is proceeding a research about economical thickness and methodologies for the design of reinforced roadbed. Field test section is located at Kyungbu line which is from Suwon to Cheonan In this study, field test were measured a track irregularity with several types of reinforced roadbed materials by using Track Master. The field testing were conducted between March, 2006 and April, 2008.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2007.04a
• /
• pp.289-294
• /
• 2007

Virtual reality (VR) technology for construction project includes 3D CAD application and 4D CAD system for visualizing construction schedule data. 3D CAD application is more important in the design phase and 4D CAD system is effective tool in the construction phase. This study suggests a methodology to develop VR functions that can be used for project life cycle. The results of this study includes composition algorithms to make VR systems such as bird's eye view system, VR drawings system, VR telepresence system and VR risk management system. Those methodologies can be used for integrated VR system with nD CAD object.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.10a
• /
• pp.23-26
• /
• 2004

최근 정보통신서비스 시장은 다양한 요인에 의해 서비스 사업자간의 경쟁심화와 고객요구수준의 향상 등의 추세가 강화되고 있으며, 경쟁양상 측면과 고객이 사업자에게 요구하는 서비스 제공특성 등의 측면에서 많은 변화가 일어나고 있다. 특히, 정보통신서비스에 대한 서비스 제공 품질수준과 관련하여 SLA (서비스수준협약)의 중요도는 점차 증대하고 있으나, 대부분 해외의 선진사레나 고객의 요구내용 (VOC)을 여과 없이 반영해서 제공하는 추세여서, 사업자의 입장에서는 SLA를 제공하는 과정에서 다양한 유형의 문제점을 안고 있으며, 실질적인 효과를 거두고 있는 사례를 찾아보기 힘든 상황이다. 이와 같은 배경에서, 본 논문에서는 최근 다양한 분야에서 폭 넓게 활용되고 있는 6 시그마 방법론에서 제시하고 있는 다양한 도구들을 활용하여, 사업자가 SLA 제공체계를 수립하는 과정에서 필요한 서비스품질 보증항목의 도출 및 보증수준의 설정, 측정과 관련된 다양한 요소에 대한 설정 및 관리방법, 보상수준의 설정 등에 대한 체계적인 제공방법에 대해서 제시하고자 한다.

• International Journal of Control, Automation, and Systems
• /
• v.2 no.3
• /
• pp.398-405
• /
• 2004

A human-friendly interactive system that is based on the harmonious symbiotic coexistence of humans and robots is explored. Based on the interactive technology paradigm, a robotic cane is proposed for blind or visually impaired pedestrians to navigate safely and quickly through obstacles and other hazards. Robotic aids, such as robotic canes, require cooperation between humans and robots. Various methods for implementing the appropriate cooperative recognition, planning, and acting, have been investigated. The issues discussed include the interaction between humans and robots, design issues of an interactive robotic cane, and behavior arbitration methodologies for navigation planning.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.6
• /
• pp.1273-1283
• /
• 2004

On these days concrete knowledge more than simple information is required in order to do something. In this paper we researched the development methods and design of the Knowledge Management System(KMS) to effectively utilize the human resources and various kinds of intellectual resources of the universities, which is the mecca of the knowledge and technology. We gave our focus to the methodologies that makes it possible to implement the KMS with the least costs based on the available databases and infrastructures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.805-807
• /
• 2017

유전자 알고리즘을 이용하여 스스로 테트리스 게임을 플레이하는 AI 기법을 제안한다. 테트리스에 필요한 요소들을 고려하여 각 요소마다 가중치를 곱한 값을 통해 블록을 이동시킬 자리를 정한다. 해당 알고리즘은 8가지의 고려 요소를 가지며, 각 요소별 최적의 가중치를 구하기 위해 유전자 알고리즘을 적용하였다. 본 연구의 성능을 분석하기 위하여 직접 설계 제작한 테트리스로 게임을 정확하게 진행해 나가는가를 실험하였다. 실험 결과, 제안 기법에 따라 테트리스를 진행하는 것을 확인하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.1B
• /
• pp.55-63
• /
• 2003

Conventional command-based communication services are rapidly substituted by multimedia web-based communication services at most recent times As the result, many valuable database and services that were developed by investing lots of human and material resources become to be useless Therefore in this paper we researched the methodologies and techniques for designing and implementing a multimedia web-based database system that made users easily access to database and services by updating the conventional command-based database services.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1999.10a
• /
• pp.325-330
• /
• 1999

Web-based simulation is one of the most interesting field of simulation research today. Among many research area of web-based simulation, we concern about what a effective way of building simulation model is since creating comprehensive simulation models can be expensive and time consuming. So this paper discusses how to integrate distributed simulation sub-models as objects for constructing the required simulation model which is more large and complex. We introduce two web-oriented methodologies (such as JIDL, CORBA) and the concepts of agent for assisting modelers to integrate simulation models scattered over the web. SINDBAD, which we designed, is a simulation environment which makes it possible constructing a simulation model with distributed model objects on the web and performing the parallel simulation in a distributed way. It is organized according to design patterns in the object oriented concept. Actually we are on the premise that all the distributed objects are originally composed in a CORBA-compatible way to start with our prototype of SINDBAD.