• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.637-639
• /
• 1995

Since power systems tend to be more large and complex, expert system substituted for the decision-making achieved by the power system operation expert is required. So far, expert system has been used for fault diagonosis and voltage-reactive power control and so on. In the expert system developed using 'C' language, the faulted element is estimated using the AND operation of lists which are acquired from the information on operated relays. It is also considered to identify the misoperation of protective devices using CF(Certainty Factor), and operation failure of those using the data base of parameter group list. The developed expert system is applied to a 6-bus sample system and through the case studies. It is shown that the expert system is very useful.

• Journal of the Korea Institute of Building Construction
• /
• v.6 no.2 s.20
• /
• pp.65-72
• /
• 2006

The amount of water demand at large buildings is increasing with the concentration of population to city and a rise in the standard of living in the city area. In this reason the Water Shortage is expected and a problem of water pollution by the city sewerage is increasing. One of method of saving city water demand and city sewer is applying recycling water system witch make used water reuse by purification of water. The application of recycling water system witch make used performed since the application of Lotte World Complex. But the popularization of this system is not activated because of cost problem and feeling of people to the water recycled. So in this study, provide application method for recycling water system by propose the estimation method of optimal sizing of recycling water system.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.2005-2013
• /
• 2008

Urban transit is a large scaled complex system which combines rolling stocks, power supply, signal communications, tracks & stations etc. KRRI develops nine key devices since July, 2007 as a part of the second phase of project on the standardization of urban rail transit system, which include information-communication system, station facilities, AC-DC current electric power system in urban transit. We promote the project under two directions, i.e. user-customer oriented standardization and strategic standardization for leading technologies in urban transit. In this paper, we present development plan of these key systems in view of system life cycle based on system engineering standards KSX ISO/IEC 15288 which supplies the common fundamental frame to describe the life cycle of artificial systems. System engineering process of KSX ISO/IEC 15288 are helpful to efficiently develop those key devices, although it is difficult to apply the standard identically to the key devices with the varieties and characteristics.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.24 no.66
• /
• pp.1-10
• /
• 2001

Simulation-Based Expert System(SIMBES) is a very effective tool to solve complex antral hard problems. The SIMBES model includes a simulator, a feature extractor, a machine learning system, a performance evaluator, and a Knowledge-Based Expert System(KBES). Since SIMBES depends on Problem domains, a schedule-based material requirements planning problem, which is NP-hard, was selected to exemplify the SIMBES model. To implement the SIMBES application in Smalltalk paradigm, a system class hierarchy was constructed. The hierarchy consists of five large classes such as Job Generator, Job Scheduler, Job Evaluator, Inference Engine, and Executive System. Several classes inside these classes were identified. Additionally, instance protocols about all classes have been described in terms of messages and pseudo methods. These protocols can be implemented easily by any other object-oriented languages. Furthermore, these results may be used as a skeletal system to develop a new SIMBES efficiently, especially when the application is related to other scheduling problems.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.16 no.3
• /
• pp.260-267
• /
• 2013

A combat system for navy's battleship is a system of systems who supports naval indigenous operations by integrating and inter-operating many different kind of weapon and non-weapon systems, which has characteristics of large-scale complex computing system. This paper considers a characteristics of naval combat system which has been developed by domestic technology and suggests a way to improve future naval combat system in terms of computing architecture by applying commercial real-time operating system technologies. This paper also provides an evaluation criteria for combat system adaptability of real-time operating systems.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10a
• /
• pp.389-394
• /
• 1991

The surface-to-air missile system using Command to Line-Of-Sight (CLOS) guidance law is represented by complex nonlinear differential equations with 6 degree-of-freedom. This paper presents the characterictics of missile system and the effect of various error sources by Monte-Carlo simulation method. By simulation the part of playing a main role in the surface-to-air missile system is radar. Therefore for the performance of missile system the development of the technique reducing the error of radar is required. And the effect of accelerometer error is a few large, too. But, because accelerometer costs cheap this problem is solved easily. And the main error source of missile system data is the thrust, which affects directly to acceleration. The result is the important information about designing and fabricating missile system. And this makes the missile system best because of sharing elaborate and expense effectively.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.435-435
• /
• 2000

Light Rail Transit (LRT) system is a complex and large system in which there are many subsystems, interfaces, functions and demanding performance requirements. Because many contractors participate in the development, it is necessary to apply methods of sharing common objectives and communicating effectively among all of the stakeholders. This paper shows not only the methodology and the results of computer-aided systems engineering including requirement management, functional analysis and architecting LRT system, but also propose a tool to help manage a project by linking WBS (Work Breakdown Structure), work organization and PBS (Product Breakdown Structure). The application of computer-aided tool RDD-100 provides the capability to model product design knowledge and decisions about important issues such as architecting the top-level system. The product design knowledge will be essential in integrating the following life-cycle phase activities over the life of the LRT system. Additionally, when a new generation train system is required, the reuse of the database can increase the system design productivity and effectiveness significantly.

• Nuclear Engineering and Technology
• /
• v.41 no.7
• /
• pp.953-968
• /
• 2009

It is important to accurately predict the temperature and density distributions in large stratified enclosures both for design optimization and accident analysis. Current reactor system analysis codes only provide lumped-volume based models that can give very approximate results. Previous scaling analysis has shown that stratified mixing processes in large stably stratified enclosures can be described using one-dimensional differential equations, with the vertical transport by jets modeled using integral techniques. This allows very large reductions in computational effort compared to three-dimensional CFD simulation. The BMIX++ (Berkeley mechanistic MIXing code in C++) code was developed to implement such ideas. This paper summarizes major models for the BMIX++ code, presents the two-plume mixing experiment simulation as one validation example, and describes the codes' application to the liquid salt buffer pool system in the AHTR (Advanced High Temperature Reactor) design. Three design options have been simulated and they exhibit significantly different stratification patterns. One of design options shows the mildest thermal stratification and is identified as the best design option. This application shows that the BMIX++ code has capability to provide the reactor designers with insights to understand complex mixing behavior with mechanistic methods. Similar analysis is possible for liquid-metal cooled reactors.

• Geomechanics and Engineering
• /
• v.21 no.6
• /
• pp.551-564
• /
• 2020

High-stress and complex geological conditions impose great challenges to maintain excavation stability during deep underground mining. In this research, large anisotropic deformation and its management by support system at a deep underground mine in Western Australia were simulated through three-dimensional finite-difference model. The ubiquitous-joint model was used and calibrated in FLAC3D to reproduce the deformation and failure characteristics of the excavation based on the field monitoring results. After modeling verification, the roles of mining depth also the intercept angle between excavation axis and foliation orientation on the deformation and damage were studied. Based on the results, quantitative relationships between key factors and damage classifications were presented, which can be used as an engineering tool. Subsequently, the performance of support system installation sequences was simulated and compared at four different scenarios. The results show that, first surface support and then reinforcement installation can obtain a better controlling effect. Finally, the influence of bolt spacing and ring spacing were also discussed. The outcomes obtained in this research may play a meaningful reference for facing the challenges in thin-bedded or foliated ground conditions.

• The KIPS Transactions:PartD
• /
• v.17D no.6
• /
• pp.405-414
• /
• 2010

A rule is defined as a case to determine the target values according to combination of various Business factors. The information system is used to represent enterprise's business, which includes and implements the amount of these rules to Rule-Based System. A Rule-Based System can be constructed by using the rules engine method or Relational Database technology. Because the rules engine method has some disadvantages, the Rule-Based System is mostly developed with Relational Database technology. When business scales become larger and more complex, a large number of various rule cases must be operated in system, and processing these rule cases requires additional time, overhead and storage space, and the speed of execution slows down. To solve these problems, we propose a simplification algorithm that converts a large amount of rule cases to simplification rule cases with same effects. The proposed algorithm is applied to hypothetical business rule data and a large number of simplification experiments and tests are conducted. The final results proved that the number of rows can be reduced to some extent. The proposed algorithm can be used to simplify business rule data for improving performance of the Rule-Based System implemented with the Relational Database.