• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.227-234
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• 2005

In this paper, a smart wireless MEMS-based accelerometer(MA) system has been designed and experimented for smart monitoring system of civil structures. Various performance and experimental tests have been carried out to evaluate whether this system is suitable for monitoring system of civil structures. First, we examined its sensitivity, resolution, and noise, specifically to evaluate the performance of the smart wireless MA system. The results of experiments enabled us to estimate performance of the MA in SWMAS in comparison to the value of data sheet from MA. Second, characteristics of model structure were analyzed by the ambient vibration test based on the NExT combined with ERA. Finally, this analysis was compared to the one that was made by FE results, and the comparison proved that a smart wireless MA system was fitted in smart monitoring system effectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6A
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• pp.765-778
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• 2008

Performance Profiles are essential to predict the performance variation over time for the bridge management system (BMS) based on risk management. In general, condition profiles based on experts opinion and/or visual inspection records have been used widely because obtaining profiles based on real performance is not easy. However, those condition profiles usually don't give a good consistency to the safety of bridges, causing practical problems for the effective bridge management. The accuracy of performance evaluation is directly related to the accuracy of BMS. The reliability of the evaluation is important to produce the optimal solution for distributing maintenance budget reasonably. However, conventional methods of bridge assessment are not suitable for a more sophisticated decision making procedure. In this study, a method to compute quantitative performance profiles has been proposed to overcome the limitations of those conventional models. In Bridge Management Systems, the main role of performance profiles is to compute and predict the performance of bridges subject to lifetime activities with uncertainty. Therefore, the computation time for obtaining an optimal maintenance scenario is closely related to the efficiency of the performance profile. In this study, the Response Surface Method (RSM) based on independent and important design variables is developed for the rapid computation. Steel box bridges have been investigated because the number of independent design variables can be reduced significantly due to the high dependency between design variables.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.8
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• pp.39-46
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• 1998

One of the main techniques for diagnosing heart disease is by examining the electrocardiogram(ECG). Many studies on detecting the QRS complex, P, and T waves have been performed because meaningful information is contained in these parameters. However, the earlier detection techniques can not effectively extract those parameters from the ECG that is severely contaminated by noise source. In this paper, we performed the extracting parameters from and recovering the ECG signal using wavelets transform that has recently been applying to various fields.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.5
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• pp.231-239
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• 2014

This paper represents a method of existing building energy simulation using energy audit data. Energy audit must be carried out for reasonable analysis, because characteristics of existing buildings such as efficiency of fan, pump, flow rate, pressure, COP and operating schedule could be changed during the building operation. These building characteristics should be measured to estimate actual energy consumption of the existing building. In this study, we conducted energy audit and calculated energy savings for a 7-stories building as a case-study. The energy audit data were used to calibrate the building model of EnergyPlus simulation. Baseline model validated according to M&V guideline index. As a result, building characteristics are significant parameters making a big impact on energy savings in existing buildings.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.115-125
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• 2009

In these days, carbon fiber-reinforced polymers (CFRP) have been widely used for retrofitting and/or strengthening structural elements. However, there are not enough test data to predict the long-term performance of the retrofitted structures exposed to freeze-thawing cycles. This paper presents the results of experimental program undertaken to investigate the effects of freeze-thawing cycling (from-18 to $4^{\circ}C) on the behavior and failure characteristics of reinforced concrete (RC) beams strengthened in shear with CFRP sheet and plate using acoustic emission (AE) technique.

• Korean Journal of Cognitive Science
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• v.9 no.1
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• pp.31-39
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• 1998

This paper describes an electronic performance support system called HELPS(Handler Electronic Learning Performence Support) for semiconductor testing e equipment. The purpose of this system is to improve productivity of operators by providing just-in-time, on-the-job, mutimedia-based system information for operational support, training, and knowledge-based trouble shooting and repair. HELPS is composed of a operation module and a trouble shooting module. The operation module uses multimedia and hypermedia to provide the detailed and easily accessible information about equipment to users. Multimedia incorporate multiple. media forms including still and video images. animations 'texts' graphics. and audio. Hypermedia a are provided through a hierarchical information structure which offers not only specific information which is needed to perform a task to experienced operators. but detailed system guidance and information to novice operators. The trouble shooting module is composed of an integrated mutimedia-supported expert system which assists operators in trouble shooting and equipment repair. After diagnosis through the use of the expert system. multimedia advice is presented to the user in either still images with text or motion sequences with sound HELPS is evaluated in term of training time and trouble shooting and repair time. It improved productivity by saving more than 30% of the total time used without the system. This s system has the potential to improve productivity when it is used with ICAIOntellignet Computer Aided Instruction) and virtual reality.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.135-138
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• 2002

현대 사회는 정보시스템 및 정보통신망에 대한 의존도가 높아지고 있으며 이러한 기반시설들이 국가의 안보에 막대한 영향을 미친다. 그에 대비하여 사회 여러 분야에서 Hacking 및 사이버테러 등 주요 기반구조 침해위협을 방지하기 위해서 많은 노력이 이루어지고 있으며 본 논문에서는 시뮬레이션을 이용한 Network의 취약성 진단시스템 및 Real Network의 능동적인 구성설정의 변경을 통한 보안성 향상에 대한 연구를 통하여 기존의 보안도구 보다 한 차원 진보된 성능의 시스템을 제안한다. 본 시스템은 네트워크의 변화에 대해 수동적인 기존의 보안 도구에 비하여 시뮬레이션이라는 기법을 이용하여 Network의 변화에 맞추어 원하는 시기에 수시로 바뀌는 네트워크 취약성의 정도를 측정할 수 있고 취약성에 대한 대응정책을 토대로 Real Network를 구성하는 각 Component들의 구성설정을 적절하게 변화시켜 줄 수 있는 Agent 시스템으로 Network을 능동적으로 Control하여 보다 효율적인 방법으로 보안성을 강화시킬 수 있으며 네트워크/시스템의 보안성이 현저하게 향상될 수 있을 것이다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2046-2047
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• 2008

본 논문에서는 가공 배전선로에 사용되고 있는 피뢰기의 상태 진단을 위한 누설전류 분석기법에 대해 기술하였다. 현장에서 다양한 환경 스트레스를 받고 있는 피뢰기는 점차 열화가 진행되어 선로 고장의 원인이 되므로 이를 사전에 검출하여 고장을 예방하는 것이 중요하다. 피뢰기 이상을 효과적으로 검출하는 방법의 하나로 사용되고 있는 누설전류 측정방법에 대해 평가하였다. 피뢰기 누설전류는 측정 환경에 영향을 받을 수 있기 때문에 현장 측정한 결과와 실험실에서 측정한 결과를 비교하여 분석하여 환경영향을 보정하여 판단하는 방법을 고려하였다. 또한 온도에 따른 누설전류 값의 변화를 분석하여 누설전류에 의한 피뢰기 상태 판단 근거를 마련하였다. 이를 위해 현장에서 설치 운용되고 있는 피뢰기를 지역별로 고르게 발취하여 측정 분석하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.799-801
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• 2005

현재 마이크로어레이 기술은 대량의 유전자 발현 데이터 특히 종양과 관련한 데이터들을 쏟아내고 있다. 이 데이터를 기반으로 종양의 종류에 따른 유전자들의 차별적 발현 양상을 분석하고 발현량의 변화가 두드러지는 유전자들에 기반하여 종양을 분별할 수 있는 분류 모델을 구축한 후, 이것을 종양을 진단하거나 예측하는데 이용할 수 있다. 대부분의 종양은 생성 매커니즘에 따라 세부 부류로 나눌 수 있고 세부 부류에 따라 치료 방법이나 예후가 달라지므로, 정확하게 종양의 세부 부류를 진단하는 것이 매우 중요하다. 본 논문에서는 종양의 종류에 따라 발현량이 민감하게 변화하는 유전자들을 뽑아내기 위한 특징 추출 방법들과 추출된 특징들에 기반해서 종양의 종류를 분별할 수 있는 기계학습 알고리즘들의 조합들의 성능을 비교분석 하였다.

• The Journal of Bigdata
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• v.1 no.1
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• pp.19-22
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• 2016

Many Studies have been actively conducted on the early diagnosis of the crop pest utilizing IT technology. The purpose of the paper is to discuss on the image processing method capable of detecting the crop leaf pest prematurely by analyzing the image of the leaf received from the camera sensor. This paper proposes an algorithm of diagnosing leaf infection by utilizing an improved K means clustering method. Leaf infection grouping test showed that the proposed algorithm illustrated a better performance in the qualitative evaluation.