• Journal of the Korean Society of Safety
• /
• v.34 no.5
• /
• pp.159-166
• /
• 2019

The seismic PSA is to probabilistically estimate the potential damage that a large earthquake will cause to a nuclear power plant. It integrates the probabilistic seismic hazard analysis, seismic fragility analysis, and system analysis and is utilized to identify seismic vulnerability and improve seismic capacity of nuclear power plants. Recently, the seismic risk of domestic multi-unit nuclear power plant sites has been evaluated after the Great East Japan Earthquake and Gyeongju Earthquake in Korea. However, while the currently available methods for system analysis can derive basic required results of seismic PSA, they do not provide the detailed results required for the efficient improvement of seismic capacity. Therefore, for in-depth seismic risk evaluation, improved system analysis method for seismic PSA has become necessary. This study develops a system analysis method that is not only suitable for multi-unit seismic PSA but also provides risk information for the seismic capacity improvements. It will also contribute to the enhancement of the safety of nuclear power plants by identifying the seismic vulnerability using the detailed results of seismic PSA. In addition, this system analysis method can be applied to other external event PSAs, such as fire PSA and tsunami PSA, which require similar analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.336-341
• /
• 2003

In this paper, resonance durability analysis technique is presented for the fatigue life assessment considering dynamic effect of a vehicle system. In the resonance durability analysis, the frequency response and the dynamic load on frequency domain are used. Multi-body dynamic analysis, finite element analysis, and fatigue life prediction method are applied for the virtual durability assessment. To obtain the frequency response and the dynamic load, the computer simulations running over typical pothole and Belgian road are carried out by utilizing vehicle dynamic model. The durability estimations on the rear suspension system of the passenger car are performed by using the presented technique and compared with the quasi-static durability analysis. The study shows that the fatigue life considering resonant frequency of vehicle system can be effectively estimated in early design stage.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.520-522
• /
• 2005

This paper presents the design and analysis of the electromagnetic system such as jumping ring system. Also, we study the characteristics of dynamics for system with initial parameter. For the propose of system control,, first, we simulate the MATLAB tool solving coupled differential equations with electric parameter, inductance and mutual inductances. Therefore, we design a jumping ring system using design results, implement, and analyze the jumping ring system real situation. For the near time, we present a control process, and compare of real system and software technique.

• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.381-383
• /
• 2001

A system engineering play a key role in new signalling system development. The signalling system development process consists several phases which are requirement analysis, functional analysis, system synthesis and system analysis. Each phase of the development are decomposed according to system engineering process. The key topics to be considered are shown in the each phase such as safety. This paper shows the application of system engineering process to a signalling system development.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.265-271
• /
• 2003

System engineering is one of the most important research topics in railway system for developing new railway system or improving existed system. The system engineering methods have been applied to innovate railway system. The system engineering activities, which are requirement analysis, functional analysis, system synthesis and analysis, sometimes requires longtime and tiresome works to fix some ideas level into some concrete forms. The system engineering using objected oriented method relieves the hard works of system engineering and clarifies the system engineering objects from its ambiguities. In this paper, we presented requirement model, analysis model and design model using objected oriented approach and showed the consistency of the system engineering work with an example of Automatic Train Control System.

• The Journal of Information Technology and Database
• /
• v.6 no.2
• /
• pp.115-130
• /
• 1999

The price structure of housing market varies depending upon market price policy rather than low or high price policy because of IMF. The object of this study is to develop an analysis system for analyzing housing market and its demand. The analysis system consists of four major categories: macro index analysis, market decision analysis, housing market analysis, and consumer analysis. We model each category by using a variety of techniques such as generalized linear model, categorical analysis, bubble analysis, drill-down analysis, price sensitivity meter analysis, optimum price index analysis, profit index measurement analysis, correspondence analysis, conjoint analysis, and multidimensional scaling analysis. Seoul apartment data is analyzed to demonstrate the practical usefulness of the system.

• Journal of the Korean Society of Systems Engineering
• /
• v.11 no.1
• /
• pp.73-79
• /
• 2015

This paper describes boundary analysis for modeling Aircraft Carrier Sortie Generation System(CVSGS). An aircraft carrier, as a super system, is a warship going into battle by operating a number of aircraft on deck and it should be lay down a definition about aviation operations interacting between aircraft carrier and carrier air wing in small deck area. For this reason this paper models common aviation support system for generating sortie basic unit of carrier aviation operations unlike to general warship and defines boundaries between this system and aircraft carrier and carrier air wing. This paper analysis activities of aircraft carrier and embarked carrier air wing in carrier aviation operations, and analysis and defines boundaries Aircraft Carrier Sortie Generation System(CVSGS) to perform core functions in interacting between aircraft carrier and embarked carrier air wing.

• Journal of the Korean Society of Systems Engineering
• /
• v.12 no.1
• /
• pp.105-112
• /
• 2016

An aircraft must be designed to minimize system failure rate for obtaining the aircraft safety, because the aircraft system failure causes a fatal accident. The safety of the aircraft system can be predicted by analyzing availability, reliability, and maintainability of the system. In this study, the reliability and the maintainability of the hydraulic system are analysed except the availability, and therefore the reliability and the maintainability analysis process and the results are presented for a helicopter hydraulic system. For prediction of the system reliability, the failure rate model presented in MIL-HDBK-217F is used, and MTBF is calculated by using the Part Stress Analysis Prediction and quality/temperature/environmental factors described in NPRD-95 and MIL-HDBK-338B. The maintainability is predicted by FMECA(Failure Mode, Effect & Criticality Analysis) based on MIL-STD-1629A.

• Journal of IKEEE
• /
• v.22 no.3
• /
• pp.754-758
• /
• 2018

Analysis methods in the power system are static analysis, dynamic analysis and online analysis, offline analysis. The static analysis is used for the existing power system analysis method and the static analysis is mainly used for PSS / E. However, in the real system where the value changes in real time which we are using, dynamic analysis is required which can be analyzed in real time for accurate analysis. Therefore, attention is focused on EMS (Energy Management System) and importance is increasing. Among the various EMS systems, we will cover state estimation, which is a static on-line analysis that can receive and interpret data from the acquisition point in real time. DC systems are spreading in various fields such as DC load, DC distribution, renewable energy. As such, much attention and attention are focused on the DC system. In this paper, we have studied the feasibility through the case study and the interpretation of the state estimation that can be applied to the DC system.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.55 no.5
• /
• pp.185-190
• /
• 2006

The security analysis relates to the ability of the electric systems to survive sudden disturbances such as electric short circuits or unanticipated loss of system elements. It is composed of both steady state and dynamic security analyses, which are not two separate issues but should be considered together. In steady state security analysis including voltage security analysis, the analysis checks that the system is operated within security limits by OPF (optimal power flow) after the transition of a new operating point. On the other hand, dynamic security analysis deals that the transition will lead to an acceptable operating condition. Transient stability, which is the ability of power systems to maintain synchronism when subjected to a large disturbance, is a principal component in dynamic security analysis. Usually any loss of synchronism will cause additional outages. They make the present steady state analysis of the post-contingency condition inadequate for unstable cases. This is the reason of the need for dynamics of systems. Probabilistic criterion can be used to recognize the probabilistic nature of system components and shows the possibility of system security. A comprehensive conceptual framework for probabilistic static and dynamic assessment is presented in this paper. The simulation results of the Western System Coordinating Council (WSCC) system compare an analytical method with Monte-Carlo simulation (MCS). Also, a case study of the extended IEEE Reliability Test System (RTS) shows the efficiency of this approach.