• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1537-1547
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• 2017

In this paper, a discrete-time robust current controller is proposed for PMSM drives. The structure of the proposed controller is quite simple and does not require high computational resource. The only difference of the proposed controller from the classical dead-beat controller is the integral term which can easily be implemented in a PMSM drive. The stability analysis of the proposed controller is performed accounting in parametric uncertainties, unmodelled dynamics and disturbances in the mathematical model. The boundedness of the dynamical system and asymptotic convergence of dq-axes currents to their reference values are provided under certain conditions. Various simulation and experimental studies are performed and the results taken at different operation conditions show the validity of the proposed controller.

• 대한기계학회논문집A
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• 제36권2호
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• pp.237-244
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• 2012

이 논문은 목표치 정형화 필터와 외란관측기를 활용하여 연속 냉간압연 시스템의 스트립 두께 및 장력에 대한 2-자유도 최적 제어기 설계에 관한 연구를 수행한다. 먼저 게이지 미터식과 후크 법칙을 이용하여 스트립 두께 및 장력에 관한 동적모델을 각각 구축한다. 다음에는 동적모델을 기반으로 2-자유도 제어기를 설계한다. 여기서 피드포워드 제어기는 목표치 정형화 필터와 외란 관측기를 활용한 제어기로 구성되며, 피드백 제어기는 역 최적 제어기로 설계된다. 끝으로 컴퓨터 시뮬레이션을 통하여 이 논문에서 제안한 2-자유도 최적 제어기가 연속 냉간압연 시스템의 기존 제어기보다 스트립 두께 및 장력에 대한 목표치 추종성능과 외란 제거성능이 매우 우수함을 보인다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.128-130
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• 2016

온라인 콘텐츠와 모바일 단말기의 대중화에 따라 국내 디지털 콘텐츠 산업은 높은 성장률을 보이면서 빠르게 발전하고 있다. 본 연구에서는 DEA 모형을 이용하여 온라인 디지털 콘텐츠 산업의 기술적 효율성을 측정하고 효율성 제고를 위한 시사점을 모색한다. 실증분석을 위한 투입요소로는 업종별 사업체수와 종사자수를 사용하였고, 산출요소로는 총매출액을 사용하였다. 실증분석 결과, 온라인 디지털 콘텐츠 산업의 기술적 효율성은 상당히 낮은 수준인 것으로 나타났으며 이는 주로 규모의 비효율성에 기인한 것으로 분석되었다. 이와 같은 결과는 기술혁신역량을 강화하기 위한 산업성장전략 추진이 필요함을 시사하는 것으로 향후 온라인 디지털 콘텐츠 산업의 경쟁력 제고에 도움이 되는 실질적인 참고자료로 활용될 것으로 기대된다.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.119-126
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• 2021

The study develops methodological aspects for modeling the determining impact of modernization on the enterprise's economic security in development competitive conditions using the model of speed, stability and spaciousness of modernization. Modeling the determining impact of modernization on the enterprise's economic security in a competitive conditions involves: firstly, the formation of estimated modeling indicators in accordance with the speed, stability and spaciousness of the enterprise's modernization; secondly, establishing the weight of indicators in the assessment system using the tools of cognitive judgment; thirdly, the establishment of reference values of sound evaluation indicators; fourthly, the calculations of the integrated impact assessment of the modernization's determining impact modeling on the enterprise's ensuring economic security in a competitive conditions; fifthly, conducting calculations and analytical summarization of the results. To determine a comprehensive integrated indicator of the modernization changes impact on the competitiveness and economic security of enterprises, we use the correlation method of the calculated value with the reference value, as well as use weights for groups of calculations. Approbation of modeling of determining influence of modernization on maintenance of economic safety of the enterprise in competitive conditions of development by authors was carried out concerning such enterprises, as: JSC "Ukrzaliznytsia", SE "Ukraerorukh", SE IA "Boryspil", SE "Ukrposhta", KP "Kyivpastrans".

• 대한인간공학회지
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• 제35권3호
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• pp.143-153
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• 2016

Objective: The purposes of this study are to survey needs for changing accident investigation from blaming to systems approach and to briefly summarize systems-based accident analysis techniques. Background: In modern complex socio-technical systems, accidents are caused by a variety of contributing factors including human, technical, organizational, social factors, not by just a single violation or error of a specific actor, but accidents investigation used to be focused on the incorrect action of individuals. A new approach investigating causes of accidents as a symptom of a deficient system is required. Method: This study was mainly based on survey of literatures related to accidents, accidents investigation, which included academic journals, newspapers, etc. Results: This study showed that accidents investigation of Korea focusing on blaming is problematic. This was confirmed by two concepts of migration and hindsight bias frequently found in accident causation studies, and an attribute of accidents having varying causes. This was illustrated with an example of Sewol ferry capsizing accident. Representative systems-based accident analysis models including Swiss cheese model, AcciMap, HFACS, FRAM and STAMP were briefly introduced, which can be used in systematic accidents investigations. Finally, this study proposed a procedure for establishing preventive measures of accidents, which was composed of two steps: public inquiry and devising preventive measures. Conclusion: A new approach considering how safety-critical components such as technical and social elements, and their interactions lead to accidents is needed for preventing reoccurrence of similar accidents in complex socio-technical systems. Application: The results would be used as a reference or guideline when the safety relevant governmental organizations investigate accidents.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.717-720
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• 1987

This paper presents a discrete-time model reference adaptive control technique for periodically time-varying plants. It is shown that the identification problem for periodic parameters can be reduced to that of constant unknown parameters case. The global stability of the resulting closed-loop system is established using the key technical lemma of Goodwin, Ramadge and Caines.

• 한국정보통신학회논문지
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• 제19권11호
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• pp.2703-2709
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• 2015

IT 와 농업분야의 융합은 생산, 유통, 소비 분야에서의 효율과 질적 향상을 기대하게 되었고 특히 IT 영역의 정보 분석 기술과 자동제어 기술은 농산물 생산에 많은 장점을 제공하게 되었다. 네트워크 기반에서의 농업 분야 ICT확대는 기술적, 환경적인 측면에서의 어려움들을 해결하게 되었다. 본 논문에서는 IT와 접목한 스마트 농업 환경에서의 표준 기능 모델을 제안 분석하고 이를 바탕으로 한 스마트 농업에서의 기술적 서비스 요구조건 을 제시한다.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2732-2739
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• 2024

This study developed internal dose coefficients for radioiodine, tailored to the Korean population, by incorporating the Korean biokinetic model along with the Korean S values. The observed differences in dose coefficients for Koreans compared to the International Commission on Radiological Protection (ICRP) reference values noticeably varied depending on physical half-lives of iodine isotopes. For longer-lived isotopes such as I-125 and I-129, significant differences in thyroid dose coefficients were observed, with ratios (Korean/ICRP) from 0.30 to 0.55, indicating that actual doses for Koreans can be considerably lower than those evaluated based on the ICRP data. However, for short-lived iodine isotopes, such as I-131, the thyroid dose coefficients were comparable to the ICRP reference values (ratio = 0.95-0.98). These comparable dose coefficients resulted from the lower thyroidal iodine uptake in the Korean model being almost entirely offset by the higher thyroid self-absorption S values in the Korean phantoms. Additionally, this study delves into the substantial differences in absorbed dose coefficients for non-thyroidal regions and effective dose coefficients, which arose not only from physiological/anatomical variability but also technical differences in phantom design. The use of Korean-specific dose coefficients is advisable particularly in scenarios predicting elevated doses, yielding a more precise and clinically relevant dose assessment.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 추계학술논문집 2부
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• pp.529-532
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• 2011

Recently research efforts for ubiquitous technology that includes RFID(Radio Frequency Deification and sensor networks are conducted very actively The architectural framework of the USN sensor network discovery service. The survey of the USN technology is conducted on four technological visions that contain USN system technology USN networking technology and USN middleware along with the service platform, With respect to each technological division domestic and worldwide leading research projects are primarily explored with their technical features and research projects are primarily explored with their technical features and research outputs. Boasted on the result of the survey we establish a USN software model that includes data sensing, sensor data storage sensor data storage sensor data naming and sensor feed name service. This main objective of this model is to provide a reference model for the facilitation of USN application developments.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.305-310
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• 2008

건설프로젝트가 점차 대형화, 고층화 되어감에 따라 프로젝트의 관리방식에 많은 변화가 요구되고 있다. 특히, RFID/USN과 같은 유비쿼터스 기술적용이 활발히 진행되고 있는 건설물류관리 분야를 중심으로 이를 효율화하기 위한 다양한 관점의 방안이 제시되고 있다. 이에 최근 건설현장을 지능화하기 위한 목적으로 개발되고 있는 지능형 장비의 도입은 건설현장에서의 건설물류관리에 새로운 프로세스 모델개발이 요구되고 있다. 따라서 본 연구에서는 바코드 및 RFID/USN 기반의 개별 자재 형태로 제안되고 있는 기존 건설물류프로세스의 한계를 극복하고, 지능형 장비와 같은 건설물류관리의 변화요인들을 반영하여 건설공사에 사용되는 수많은 자재들이 이러한 변화된 프로세스에 쉽게 적용될 수 있는 가이드를 제공하기 위하여 지능형 건설물류관리 프로세스 레퍼런스 모델을 개발하였다.