• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.180-182
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• 2002

전력 시장의 자율 경쟁체제가 본격화되면서 기존 공급자 중심의 시장은 급격하게 사용자 중심의 시장으로 재편되어 가고 있다. 기존의 최소한의 '데이터'라는 개념은 최대한의 '정보'라는 개념으로 변화되었다. 정보의 신속하고 효율적인 관리는 변전소 자동화 시스템의 핵심 전략이자 이를 기반으로 한 전력 시스템의 IT화를 가속화시키는 원동력이 되었다. 외국의 경우 1990년대 초에 등장한 UCA2(Utility Communication Architecture)를 기반으로 한 IEC 61850(Communication Networks and systems in substation)이라는 새로운 통신 아키텍처의 도입을 서두르고 있다. IEC 61850은 IEC에서 추진중인 표준화작업의 일환으로 기존의 포인트와 태그(address) 중심의 전력 SCADA 시스템과는 달리 디바이스 및 관련 정보를 데이터 클래스 모델링을 통해 객체화하고 이 표준 객체를 통해 공통의 언어로 통신을 하는 방식으로 wire 중심이 아닌 bus 중심의 통신 방식(Ethernet)을 채용하여 대용량 정보의 실시간 전송 및 이기종간 통신이 가능한 장점을 가지고 있다. 본 논문에서는 IEC 61850을 중심으로 변전소 자동화 시스템 및 전력 시스템의 IT화와 관련된 표준 통신 프로토콜들을 소개하고 전력시스템과 변전소 환경이라는 특수 상황을 고려하여 새롭게 등장한 아키텍처의 특징을 살펴본다.

• Journal of the Korean Society for information Management
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• v.20 no.1
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• pp.341-371
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• 2003

The purpose of the study is to design the ontology-based Prescription Knowledge Management System of Oriental Medicine. The study was done with the premise that the effectiveness of the system can be improved by using ontological abstractional structure based on definition of concept, attribution and relations of words related to the specific area. The system is developed with Protege-2000 by using newly developed KPML(Korean Medicine Prescription Markup Language). The results of the study provide the model of Prescription Knowledge Management System and the possibility of implementing XML-based ontology system to the semantic web environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.382-386
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• 2011

It has been required to develop a defect detection system to perform defect detection capabilities after the bonding process in the production of RFID tags. However, we are difficult to design a system with understanding the characteristics of RFID tags and design concepts. Also we are difficult to modify even minor changes in features. In this paper, we design the defect RFID detection system using UML and object-oriented design techniques. We suggest the method for apply the UML Diagram to LabVIEW OOP and the technique for redesign the effect detection system's changes.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.523-531
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• 2011

Many of the wells which were constructed to use ground water resource are abandoned and not managed efficiently after its use. And a variety of heavy metals and organic compounds are released from the abandoned wells and this can cause ground water pollution. Therefore in this paper implemented to monitor locational information drill holes and underground water sensing information on real time basis using u-GIS environment to combined ubiquitous sensor node and GIS technology to improve these problems. In addition, this system suggests using system by UML 2.0 by analyzing variety requirement of user and between system internal modules interaction and data flow. It provides graphical user interfaces (GUI) to system users to monitor water-well related property information and its managements for each water-well at remote site by variety platform by GIS map and web environment and mobile device based on smart phone.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.47-53
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• 2011

The detection process of defective tags in most of Korean domestic RFID manufacturing companies is treated by on-hand processing after the job of chip bonding, so it has been requested to reduce the time and cost for manufacturing of RFID tags. Therefore, in this paper, we implement the system to perform the detection of defective tags after the process of chip bonding, and so provide the basis of software to establish the foundation of automation system for the detection of defected RFID tags which is requested in the related Korean domestic industrial field. We have developed the system by using UML in modeling phase and JAVA in implementation phase to reduce the cost of development of program and make it easy to maintain. The developed system in this paper shows the very enhanced performance in processing speed and perfect detection rate of defective tags, comparing to the method of on-hand processing.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.1
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• pp.46-54
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• 2008

In this paper, a low-cost impedance spectroscopy system(LCISS) suitable for modeling the electrochemical power sources such as fuel cells, batteries and supercapacitors is designed and implemented. Since the developed LCISS is composed of simple sensor circuits, commercial data acquisition board and LabVIEW software, a graphic language with powerful HMI(Human-Machine Interface), it is expected ta be widely used in substitution of the expensive EIS instruments. In the proposed system, the digital lock-in amplifier is adopted to achieve the accurate measurements even in the presence of the high level of noises. The developed hardware and software is applied to measure the impedance spectrum of the Ballard Nexa 1.2kW proton exchange membrane fuel cell stack and an equivalent impedance model is proposed based on the measurement results. The validity of the proposed equivalent circuit and the developed system is proven by the measurement of the ac power losses of the PEM fuel celt stack by the ripple current.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.574-582
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• 2018

In systems such as railways, automobiles, and airplanes, system malfunctions may lead to accidents, which often cause serious personal injury and economic loss. In previous studies, failure analysis has been performed, and safety measures derived using the component level information to reduce damage when a failure occurs. However, in functional safety concept, a focus is placed on lowering the frequency of occurrence of failures by performing risks analysis, setting up safety goals, and designing safety functions. Therefore, it is necessary to study how to determine the required safety function that can reduce the failure frequency to the acceptable level. To achieve this, we first studied a failure modeling method using SysML. It was then presented how several alternatives can be assessed to determine the desired safety function by simulating the generated SysML failure models and calculating the ability to reduce the failure frequency. A case study of a railway signaling system was done, demonstrating the effectiveness of the approach. We assessed whether the safety objectives were met for the alternative design of the railway signaling system through M & S. The results can be useful in that it can be applied from the early design phase and allow to choose the appropriate safety function that satisfies safety objectives among various design alternatives.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.25-34
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• 2006

In this paper, a method of designing the pitch control algorithm for the wind turbine generator system (WTGS) and results of nonlinear simulation are presented. For this, the WTGS is treated as a multibody system and the blade element and momentum theory are adopted to model the aerodynamic force and torque acting the rotor blades. For the purpose of controller design, the WTGS is approximated to 1 DOF system using the fact that the WTGS is eventually a constrained multibody system. Then a classical PID controller is designed and used to regulate the rotational speed of the generator. FORTRAN based nonlinear simulation program is written and used to evaluate the performance of the proposed controller at the various wind scenario and operational modes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.63-70
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• 2013

In previous research, we suggested a business process structured query language(BPSQL) for information extraction and retrieval in the business process framework, and used an existing query language with the tablization for each layer within the framework, but still had a problem to manually build with the specification of each layer information of BFP. To solve this problem, we suggest automatically to build the schema based business process model with model-to-text conversion technique. This procedure consists of 1) defining each meta-model of the entire structure and of database schema, and 2) also defining model transformation rules for it. With this procedure, we can automatically transform from defining through meta-modeling of an integrated information system designed to the schema based model information table specification defined of the entire layer each layer specification with model-to-text conversion techniques. It is possible to develop the efficiently integrated information system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.8
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• pp.791-797
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• 2017

Today, we are using computer simulations in various engineering disciplines to reduce the time and cost of product development. The scope of simulations is increasingly complex and diverse for different fields such as mechanical, electrical, thermal, and fluid. Thus, it is necessary to use integrated simulations. In order to overcome these problems, a language has been developed to effectively describe and implement simulations is Modelica. To model and simulate a system, physical models can be broadly divided into causal and acausal models. The most important feature of Modelica is acausal programming. In this study, we will introduce simple concepts and explain about the usage of Modelica. Furthermore, we will explain the vibration analysis of a two degree-of-freedom system and the design of appropriate parameters by using Modelica.