• Journal of Information Processing Systems
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• 제13권5호
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• pp.1168-1182
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• 2017

In the past decades, various image regularization methods have been introduced. Among them, total variation model has drawn much attention for the reason of its low computational complexity and well-understood mathematical behavior. However, regularization parameter estimation of total variation model is still an open problem. To deal with this problem, a novel adaptive regularization parameter selection scheme is proposed in this paper, by means of using the local spectral response, which has the capability of locally selecting the regularization parameters in a content-aware way and therefore adaptively adjusting the weights between the two terms of the total variation model. Experiment results on simulated and real noisy image show the good performance of our proposed method, in visual improvement and peak signal to noise ratio value.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.206-214
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• 2013

This paper proposes a new method for monitoring local voltage stability using the saddle node bifurcation set or loadability boundary in two dimensional power parameter space. The method includes three main steps. First step is to determine the critical buses and the second step is building the static voltage stability boundary or the saddle node bifurcation set. Final step is monitoring the voltage stability through the distance from current operating point to the boundary. Critical buses are defined through the right eigenvector by direct method. The boundary of the static voltage stability region is a quadratic curve that can be obtained by the proposed method that is combining a variation of standard direct method and Thevenin equivalent model of electric power system. And finally the distance is computed through the Euclid norm of normal vector of the boundary at the closest saddle node bifurcation point. The advantage of the proposed method is that it gets the advantages of both methods, the accuracy of the direct method and simple of Thevenin Equivalent model. Thus, the proposed method holds some promises in terms of performing the real-time voltage stability monitoring of power system. Test results of New England 39 bus system are presented to show the effectiveness of the proposed method.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2001년도 추계학술발표논문집 (하)
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• pp.1597-1600
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• 2001

In-Service-Monitoring을 통하여 네트웍 계층에서 성능저하와 전달되어지는 QOS의 영향을 감시하여 Pro-Active 매니지먼트가 가능하다. 그 결과로서 SLA 보증을 위반하기 전에 성능저하를 조기 발견하여 행동을 취한 수 있게 한다. 본 논문에서는 사용자의 요구조건을 만족하기 위한 네트웍의 구성과 SLA 측정의 제약조건들을 고려하고 Policy Based Routing이 적용되는 네트웍에서 Technology-Specific Parameter인 IP Packet Loss Ratio, IP 패킷전송지연, 패킷지터, 가용도등의 SLA Parameter를 측정하였다.

• 대한기계학회논문집A
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• 제35권12호
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• pp.1593-1598
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• 2011

본 연구의 목적은 LCD 공정에서 사용되는 반송로봇의 상태감시 파라미터를 선정하고 이를 이용하여 상태감시 방법을 제안하는데 있다. LCD 반송로봇의 주행부 진동특성을 파악하기 위하여 주행부 감속기의 기어물림주파수(GMF)를 구하고, 주파수분석을 통해 이를 확인하였다. 취득데이터의 재연성을 확보하기 위하여 데이터 취득 운행 패턴을 선정하고 실험을 통해 재연성을 확인하였다. 무선데이터 취득 시스템을 구축하고 이를 이용하여 반송로봇의 상태를 감시하기 위한 기어물림 주파수를 중심으로 파라미터로 선정하였다. 취득된 데이터의 표준편차를 이용하는 상태감시 방법과 진폭의 배수를 이용하는 상태감시 방법을 제안하였다.

• 융합신호처리학회논문지
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• 제11권3호
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• pp.197-202
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• 2010

본 논문에서는 가정 내에서 보다 편리하게 건강모니터링을 수행하기위한 홈헬스케어용 다중생체 계측시스템을 구현하였다. 측정대상 신호는 가정 내에서 일반인들이 쉽게 측정할 수 있으며 많은 건강정보를 포함하고 있는 심전도, 맥파 그리고 체온을 대상으로 하였다. 구현된 생체계측 시스템은 신호검출을 위한 센서부, 각각의 생체신호를 증폭 및 필터링하기 위한 아날로그 신호처리부, 아날로그신호를 디지털로 변환하여 처리하고 시스템 주변장치를 제어하기위한 시스템제어부 및 모니터링 프로그램으로 구성되었다. 구현된 시스템은 시스템자체에서의 디스플레이뿐만 아니라 블루투스무선통신을 통해 홈서버용 PC 또는 웹을 통해 원격모니터링이 가능하여 원격건강정보 모니터링에 활용이 가능하다. 구현된 생체신호 계측시스템의 성능평가 결과 실제 홈 헬스케어에 적용 가능성을 확인하였다.

• 대한전기학회논문지:전력기술부문A
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• 제50권11호
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• pp.506-513
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• 2001

The islanding detection for distributed resources (DR) becomes an important and emerging issue in power system protection since the distributed generator installations are rapidly increasing and most of the installed systems are interconnected with distribution network. In order to avoid the negative impacts from islanding operations of DR on protection, operation and management of distribution system, it is necessary to effectively detect the islanding operations of DR and rapidly disconnect it from distribution network. Generally, it is difficult to detect islanding operation by monitoring only one system parameter This paper presents a new logic based islanding detection method for distributed resources(DR) which are interconnected with distribution network. The proposed method detects the islanding operation by monitoring four system parameter: voltage variation, phase displacement, frequency variation, and the variation of total harmonic distortion(THD) of current; therefore, it effectively detects island operation of DR unit operating in parallel with the distribution network. We also verified the efficiency of the proposed algorithm using the radial distribution network of IEEE 34 bus model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.588-590
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• 2006

Recently, many on-line approaches to instrument channel surveillance (drift monitoring and fault detection) have been reported worldwide. On-line monitoring (OLM) method evaluates instrument channel performance by assessing its consistency with other plant indications through parametric or non-parametric models. The heart of an OLM system is the model giving an estimate of the true process parameter value against individual measurements. This model gives process parameter estimate calculated as a function of other plant measurements which can be used to identify small sensor drifts that would require the sensor to be manually calibrated or replaced. This paper describes an improvement of auto-associative kernel regression by introducing a correlation coefficient weighting on kernel distances. The prediction performance of the developed method is compared with conventional auto-associative kernel regression.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.67-71
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• 2003

A hot press method was used to create the optimal fabrication condition for a Shape Memory Alloy(SMA) composite. The bonding strength between the matrix and the reinforcement within the SMA composite by the hot press method was more increased by cold rolling. In this study, the objective was to develop an on-line monitoring system in order to prevent the crack initiation and propagation by shape memory effect in SMA composite. Shape memory effect was used to prevent the SMA composite from crack propagation. For this system an optimal AE parameter should be determined according to the degree of damage and crack initiation. When the SMA composite was heated by the plate heater attached at the composite, the propagating cracks could be controlled by the compressive force of SMA.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.90-95
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• 2008

This article presents practical advice regarding the implementation and management of an impeccable Building Management System. The BMS was introduced to the series of computerized systems including manufacturing, storage, distribution, and quality control. Recently revised GMP regulation is requesting an improvement in drug product quality regulatory system by computer system validation. Quality is critical to guarantee the efficacy and the safety of drugs and is approved in the evaluation process after the audit trail application. HVAC parameter monitoring system will record the identity of operators entering or confirming critical data. Authority to amend entered data should be restricted to nominated persons. Any alteration to an entry of critical data should be authorized in advance and recorded with the reason for the change.

• 한국정밀공학회지
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• 제13권10호
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• pp.112-122
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• 1996

In order to monitior machine tool condition and diagnose alarm states due to electrical and mechanical faults, and expert system using diagnostic parameters of NC machine tools was developed. A model-based knowledge base was constructed via searching and comparing procedures of diagnostic parameters and state parameters of the machine tool. Diagnostic monitoring results generate through a successive type inference engine were graphically displayed on the screen of the console. The validity and reliability of the expert system was rcrified on a vertical machining center equipped with FANUC OMC through a series of experiments.