• 제어로봇시스템학회논문지
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• 제18권5호
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• pp.433-438
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• 2012

In this paper, a operation network system equipped with onboard wireless communication systems and ground-based mission control systems is proposed for swarm flight of small UAVs. This operating system can be divided into two networks, UAV communication network and ground control system. The UAV communication network is intend to exchange the informations of navigation, mission and flight status with minimum time delay. The ground control system consisted of mission control systems and UDP network. Proposed operation network system can make a swarm flight of various UAVs, execute complex missions decentralizing mission to several UAVs and cooperte several missions. Finally, PILS environments are developed based on the total operating system.

• 대한안전경영과학회지
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• 제14권2호
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• pp.167-176
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• 2012

This research studies the present status of utilization of IT in SMB, Small & Medium Business, logistics companies, and analyzes the examples of utilizing Excel VBA for building and operating IT system in SMB logistics companies. Through the study, this research suggests main issues of building and operating logistic systems and the effective way of utilizing the systems in SMB logistics companies.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 추계학술대회
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• pp.181-189
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• 2011

This research studies the present status of utilization of IT in SMB, Small & Medium Business, logistics companies, and analyzes the examples of utilizing Excel VBA for building and operating IT system in SMB logistics companies. Through this study, this research suggests main issues of building and operating logistic systems and the effective way of utilizing the systems in SMB logistics companies.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.125-127
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• 2005

In this paper, the control algorithm of DC source device for inverter starting is proposed and the control method for compensating unbalance system source on operating time in the voltage type PWM converter with driving and regenerative faculty is suggested. The maintaining way of balancing condition for converter of AC source is used the compensating unbalanced status by current control loop. Because it is possible that the unbalanced System control is used to leakage transformer not equaled reactance by each phase in rectifier system, the proposed H/W and control algorithm of rectifier system is contributed to minimize of device and rising efficiency.

• 한국안전학회지
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• 제18권4호
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• pp.35-38
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• 2003

The wire rope, one of the component of the elevator, is extremely important for the sage operation of the elevator. That is why the wire rope is replaced at a specific interval regradless of the operating conditions or the degree of damage to prevent the breakage of the wire rope. This is the waste of resources, causing economic and environmental loss. This paper has surveyed and analyzed and analyzed the status of replacing wire-rope by buildings that use elevators, in order to compare the replacement cycles of the wire rope under each operating conditions.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.69-70
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• 2007

This paper presents experimental operation with utility interactive 50kw photovoltaic generation system. And that describe configuration of utility interactive photovoltaic system which power supply for dormitory. The status of photovoltaic generation system components and interconnection and safety equipment will be summarized. This paper try analyzing the operating characteristic according to secular variation of a 50kw photovoltaic system.

• Journal of Advanced Marine Engineering and Technology
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• 제36권5호
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• pp.662-673
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• 2012

This study introduces a condition diagnosis technique for a turbine governor system. The governor system is an important control system to handle turbine speed in a nuclear power plant. The turbine governor system includes turbine valves and stop valves which have their own functions in the system. Because a turbine governor system is operated by high oil pressure, it is very difficult to maintain under stable operating conditions. Turbine valves supply oil pressure to the governor system for proper operation. Using the pressure variation of turbine and governor valves, operating conditions of the turbine governor control system are detected and identified. To achieve automatic detection of valve status, time-based and frequency-based analysis is employed. In this study, a new approach, wavelet decomposition, was used to extract specific features from the pressure signals of the governor and stop valves. The extracted features, which represent the operating conditions of the turbine governor system, include important information to control and diagnose the valves. After extracting the specific features, decision rules were used to classify the valve conditions. The rules were generated by a decision tree algorithm (a typical simple method for data-based rule generation). The results given by the wavelet-based analysis were compared to detection results using time- and frequency-based approaches. Compared with the several related studies, the wavelet transform-based analysis, the proposed in this study has the advantage of easier application without auxiliary features.

• 보건의료산업학회지
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• 제8권4호
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• pp.131-140
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• 2014

This study analyzed and compared the oral health care knowledge, oral health behaviors and oral health status of elementary school students in schools with a dental clinic and those without. This study was carried out in November of 2012. The subjects were 188 elementary school students. Structured questionnaires were completed and the SPSS(Ver.17.0) Program was used for the collected data to perform frequency analysis, a t-test, and ANOVA. For oral health knowledge, the operating school dental clinic (OSD) group had a high score of 6.72 points, while the non-operating school dental clinic (NSD) group had 5.95 points. The results were statistically significant(p<0.01). For oral health behavior, the OSD group had a high score of 5.55 points, while the NSD group had 4.59 points, which was statistically significant(p<0.01). Students in schools with school dental clinics have much better knowledge and behavior about oral health than students without school dental clinics.

• 대한기계학회논문집A
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• 제36권7호
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• pp.813-822
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• 2012

LCD 생산라인의 공정 로봇에서 방사되는 비정상 작동 소음은 로봇의 결함 탐지에 사용된다. 이 신호의 장점은 상대적으로 낮은 민감도에 비해 단지 마이크로폰을 이용하여 다수의 결함을 확인할 수 있는 것이다. 결함요소 추출을 위한 웨이브렛 변환(WPT)과 불량의 분류를 위한 인공신경망 회로(ANN)이 본 논문에서 사용되었다. 결과적으로, 비정상 작동 소음이 기계요소의 결함 진단에 효율적으로 사용될 수 있다.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.860-868
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• 2018

This article presents a new design of earthquake instrumentation that is suitable for quick decision-making after the seismic event at the nuclear power plant (NPP). The main objective of this work is to ensure more availability of the NPP by expediting walk-down period when the seismic wave is incident. In general, the decision-making to restart the NPP after the seismic event requires more than 1 month if an earthquake exceeds operating basis earthquake level. It affects to the plant availability significantly. Unnecessary shutdown can be skipped through quick assessments of operating basis earthquake, safe shutdown earthquake events, and damage status to structure, system, and components. Multidecision parameters such as cumulative absolute velocity, peak ground acceleration, Modified Mercalli Intensity Scale, floor response spectrum, and cumulative fatigue are discussed. The implementation scope on the field-programmable gate array platform of this work is limited to cumulative absolute velocity, peak ground acceleration, and Modified Mercalli Intensity. It can ensure better availability of the plant through integrated decision-making process by automatic assessment of NPP structure, system, and components.