• Annual Conference of KIPS
• /
• 2003.11c
• /
• pp.1579-1582
• /
• 2003

본 연구는 컴포넌트 검색을 위해서 컴포넌트를 컨덱스트에 의해 패싯 분류하고, 컨텍스트와 특성들간의 관련값에 대한 통계적 분석에 의해 시소러스를 구축하여 다중 패싯 분류된 컴포넌트를 효율적으로 검색할 수 있는 방법을 제안하였다. 소스 코드로부터 추출된 특성은 카이제곱 방법을 통하여 간소화가 이루어지며, E-SARM 방법을 사용하여 컨텍스트의 자동 검색이 이루어질 수 있도록 하였다. 쿼리에 대해 자동 검색된 컨덱스트에 의해 후보 컴포넌트가 선정되고, 쿼리와 컴포넌트 간의 유사도가 계산됨으로써 컴포넌트가 검색될 수 있도록 하였다. 본 연구는 다중 패싯 분류된 컴포넌트의 검색에 효율적이며, 컴포넌트의 재사용성을 높일 수 있도록 하였다.

• Journal of Elementary Mathematics Education in Korea
• /
• v.7 no.1
• /
• pp.95-101
• /
• 2003

Information-oriented society will be developed more rapidly with internet. In this trend, many foreign countries support research on mathematics education using information technology that is also needed in this country. This article shows a mathematical puzzle database related to mathematics education using Java script to be activated on internet service.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.33 no.9
• /
• pp.1495-1505
• /
• 2009

This study analyzes how well-being lifestyle and functional textile knowledge effect the perception of high functional sports/leisure wear importance. A survey was conducted among male and female sports/leisure wear consumers aged 15 and over in the Daegu and Gyeongbuk area from May $12^{th}$ to June $2^{nd}$ 2009. A total of 288 responses were analyzed using descriptive statistics, factor analysis, and regression. As a result, 9 factors were determined as sub-elements of a well-being lifestyle. Knowledge levels for functional textiles were high in elastic, UV blocking, air permeable, and antibacterial properties. The perception of high functional sports/leisure wear importance was positively influenced by functional textile knowledge and two well-being lifestyle constructing factors ('self-confidence/affirmative thinking' and 'health/environment oriented eating habits').

• Journal of Electrical Engineering and Technology
• /
• v.5 no.1
• /
• pp.61-69
• /
• 2010

This paper presents a study of a DFIG wind power generation system for real-time simulations. For real-time simulations, the Real-Time Digital Simulator (RTDS) and its user friendly interface simulation software RSCAD are used. A 2.2MW grid-connected variable speed DFIG wind power generation system is modeled and analyzed in this study. The stator-flux oriented vector control scheme is applied to the stator/rotor side converter control, and the back-to-back PWM converters are implemented for the decoupled control. The real-wind speed signal extracted by an anemometer is used for a realistic, reliable and accurate simulation analysis. Block diagrams, a mathematical presentation of the DFIG and a control scheme of the stator/rotor-side are introduced. Real-time simulation cases are carried out and analyzed for the validity of this work.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.3
• /
• pp.899-907
• /
• 2014

This paper deals with fault-tolerant control of five-phase induction motor (IM) drives under single-phase open. By exploiting a decoupled model for five-phase IM under fault, the indirect field-oriented control ensures that electromagnetic torque oscillations are reduced by particular magnitude ratio currents. The control techniques are developed by the third harmonic current injection, in order to improve electromagnetic torque density. Furthermore, Proportional Resonant (PR) regulator is adopted to realize excellent current tracking performance in the phase frame, compared with Proportional Integral (PI) and hysteresis regulators. The analysis and experimental results confirm the validity of fault-tolerant control under single-phase open.

• Industrial Engineering and Management Systems
• /
• v.11 no.1
• /
• pp.39-47
• /
• 2012

Requirements definition, which determines a project baseline, has a strong impact on the success of a project. However, since in-depth requirements are gradually revealed through the requirements definition process, the requirements definition is not a straight forward process and often falls into disorder. Thus project management standpoints are critical for the success of the requirements definition. In this paper, we present a framework and mechanisms of communication-centered project management, which controls the requirements definition process based on the situation of communication-oriented activities among stakeholders. In addition, we present a communication-centered project plan with a planning method. The project plan, which represents a time schedule of requirements definition activities, is made by a simulation-optimization algorithm using a stakeholder matrix showing the relations of requirements domains and relevant stakeholders. The effectiveness and the significance of communication-centered project management at the requirements definition phase are demonstrated by numerical examples.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.3
• /
• pp.1223-1231
• /
• 2018

The direct torque control (DTC) scheme features a simple structure thanks to stator flux-oriented control. It has the advantage of robustness against motor parameters variation since only the stator resistance is involved in the control scheme. On the other hand, the disadvantage of DTC is large torque ripple. To reduce the torque ripple, many studies on DTC-space vector modulation (DTC-SVM) schemes, which modulate the duty ratio with a fixed switching cycle, have been proposed. However, there is the difficulty in obtaining the duty ratio for DTC-SVM. Hence, this paper proposes a new duty ratio selection and stator flux calculation methods for reducing torque ripple. Simulations and experiments were carried out to determine the validity of the proposed method. The proposed scheme has simplified the duty ratio command and achieved the same control performance as the conventional duty ratio modulation method without using the information of motor parameters.

• Journal of Information Technology Services
• /
• v.5 no.3
• /
• pp.109-119
• /
• 2006

The company cannot optimize its computing environment just with individual solutions such as ERP(enterprise resource planning), SCM(supply chain management), CRM(customer relationship management), and KM(knowledge management). EAI(enterprise application integration) has emerged as an alternative that can optimize computing environment of the company through integrating such solutions and systems of distributed computing and mainframe environment. This paper reports the case study of Deakyo Co. in successfully implementing EAI. It describes project goal, project organization, project plan, the implemented EAI configuration and its features, the EAI effectiveness to the firm, and the critical success factors of the EAI project. This case study is thought to be useful as a practical guideline in carrying out EAI project of the company and to provide significant basis for constructing the theoretical framework of EAI project methodology.

• Journal of KIISE:Computing Practices and Letters
• /
• v.5 no.2
• /
• pp.263-272
• /
• 1999

본 논문은 비구조화된 이미지 저장소로부터 효과적인 이미지검색을 위한 객체 지향 검색 체계를 제시한다. 본 검색 체계에서는 이미지의 내용을 정량적 특성을 갖는 시각 정보, 비정량적 특성을 나타내는 의미 정보, 그리고 가장 추상적인 정보를 포함하는 키워드의 세 종류로 규정한다. 시각 정보와 키워드는 특별한 구조없이 집합의 형태로 저장하고, 의미 정보는 상속과 군집 관계를 갖는 계층구조로 저장하는 것이 자연스럽다. 본 논문에서는 객체지향 모델을 사용하여 비구조화된 이미지 저장소를 위한 통일된 검색 체게를 제시한다. 제안된 검색 체계의 효과를 검증하기 위해 많은 이미지 집합에 대한 실험을 수행하였다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.8
• /
• pp.1457-1465
• /
• 2016

A RCM approach to maintenance of the catenary system of electric railway is proposed. The proposed RCM approach provides a maintenance-oriented FMECA procedure to derive critical failure modes by analyzing failure effects and a RCM decision logic tree to suggest optimal maintenance works for the derived failure modes. By applying the proposed RCM procedures to the catenary system of high speed railway, it is suggested that strand breaks of dropper and voltage equalizing wire, and trolly wire wear-out are the critical failure modes for whom maintenance works based on condition monitoring should be applied instead of conventional time-based preventive maintenance. It is also proposed by reliability analysis that replacement time of dropper can be reduced from 18 years to 10 years. These results show that the proposed RCM approach can optimize the maintenance procedures of catenary system.