• 동력기계공학회지
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• 제9권4호
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• pp.187-193
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• 2005

In this paper, we proposes a man-machine interface design for fault diagnosis system with inter-node search method in a Petri net model. First, complicated fault cases are modeled as the Petri net graph expressions. Next, to find out causes of the faults on which we focus, a Petri net model is analyzed using the backward reasoning of transition-invariance in the Petri net. In this step, the inter-node search method algorithm is applied to the Petri net model for reducing the range of sources in faults. Finally, the proposed method is applied to a fault diagnosis of a refrigeration system to confirm the validity of the proposed method.

• 수산해양기술연구
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• 제51권4호
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• pp.583-591
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• 2015

The coastal stow net (stow net hereafter) in Korea is one of the major fishing methods for yellow croaker (Larimichthys polyactis), ribbon fish (Trichiurus lepturus), and anchovy (Engraulis japonicus). In terms of energy efficiency, the stow net fishery is more competitive than towing fishing gears such as trawl gears. The fishing vessels in stow net fishery have consumed less fossil fuel and also have had less carbon dioxide emission into the atmosphere. however, the stow net fishery is necessary to be regulated due to its increased output of the fleet. Therefore, it is required for fisheries authorities to manage the fishing capacity or fishing power for the assurance of fishery's sustainability. For fisheries management authorities, it is necessary to quantify data related to fishing capacity and fishing power to deploy fishery policy in a sustainable way. In terms of data for decision-making, Data envelopment analysis (DEA) method was conducted to estimate fishing capacity. Fishing power index (FPI) was also applied to calculate relative fishing power to approach the problem in a quantitative way.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2005년도 공동학술대회 논문집
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• pp.79-86
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• 2005

2004년까지 국내에 축적된 지진파 스펙트럼 D/B를 기반으로 비교적 상세하게 추정된 국내 지진특성으로부터, 190km${\omega}^2$ 지진원모델에 개략적으로 근사되었으나, 2-corner 지진원모델의 특성을 보다 뚜렷하게 보여주었다. 또한 지진원 인근 지역 (R<100km) 일본 지진관측망(F-net, KiK-net 지중, Hi-net, K-net)별로 개략적인 지진원 스펙트럼을 추정하였으며, 국내 지진관측자료부터 추정된 지진원스펙트럼과 비교하였다. 비교 결과 KiK-net 지중 및 Hi-net 등의 심부시추공 관측자료로부터 추정된 지진원스펙트럼이 국내 지진파기저면 지진원스펙트럼과 $1Hz^{\sim}30Hz$에서 유사한 수준을 나타내었다. 이러한 결과로부터 한반도 주변 해상 지진에 대해 국내 지진관측자료만으로 추정한 지진원스펙트럼의 적합성 및 추정에 사용된 국내 지진파전달, 관측소응답 특성 등의 신뢰성을 입증할 수 있었다. 또한 지진원 인근 지역의 KiK-net 지중 및 Hi-net 관측소의 응답특성과 국내 지진파기저면 관측소응답특성이 유사함을 확인하였다.

• 지구물리
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• 제8권1호
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• pp.15-21
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• 2005

2004년까지 국내에 축적된 지진파 스펙트럼 D/B를 기반으로 비교적 상세하게 추정된 국내 지진특성으로부터, 190 km

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2687-2696
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• 2023

The fuel operating ranges of fusion tokamak-based power plants are estimated using the improved engineering breakeven equation. The Lawson criterion equations are derived in the form of a triple product with a focus on engineering breakeven and the subbreakeven operating range. The relationship of fuel parameters to the power plant net efficiency is outlined. Analysis shows that the operating ranges of the suitable fuel parameters form a closed area, the size of which affects the net efficiency of the power plant. The obtained fuel operating ranges confirm the well-known fact that DT fuel is currently the only fusion fuel useable in tokamak-based fusion power plants. It is also shown that the energy utilization of pB fuel is possible in the subbreakeven operating range but is conditioned by the very high efficiency of the power plant equipment. For the utilization of DD, DHe3, and pB fuels, the required magnetic fields are indicatively estimated.

• 수산해양기술연구
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• 제59권3호
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• pp.206-214
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• 2023

Fish school monitoring technology is utilized for various purposes, such as boat fishing and resource surveys. With advancements in information and communication technology, this technology has expanded its application to remote areas. Its significance has grown in fishing sites, particularly for improving the efficiency and cost-effectiveness of set-net fishing. Set-net fishing gears are not limited to coastal areas, but are also installed in inland and remote sea regions. Consequently, fishermen require technology that allows them to quickly transmit information about approaching fish schools and enables them to perform long-term monitoring. The development of remote monitoring technology for set-net fish schools must consider crucial design factors such as communication range, transmission speed, power consumption of information modules, and operational expenses. In this study, we developed a low-power remote monitoring module for set-net fish school based on WCDMA. The module was specifically designed to minimize power consumption, allowing for communication over long distances and extended operation times in set-net fishing applications. Furthermore, we developed a web server software application that enables remote access to fish schools and provides real-time weather information. The performance of the developed module was evaluated through set-net fishing site application and experiments with moving ships on the sea. The experimental results demonstrated that the remote monitoring system, consisting of the developed low-power remote monitoring module for set-net fish school based on WCDMA and a fish finder, had an average power consumption of 4.6 W, a maximum communication range of 22.84 km, and a data transmission and reception rate of 98.79%. The maximum fish school information transmission and reception rate was 97.26%

• 전기학회논문지
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• 제60권7호
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• pp.1347-1353
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• 2011

While most of the existing protection schemes have been designed with local information around individual components, these local schemes are not considered capable of protecting the modern electric power gird with growing complexity. Recent blackouts in North America and Europe have renewed the emphasis on coordinated protection and control actions to avoid systemwide blackouts, utilizing all of the available grid information. Thus, this paper proposes a new methodology, Agent-based Colored Petri Net (ACPN) modeling for systematically representing, modeling and analyzing information flows and interactions among the entities of the electric power grid. The paper demonstrates its efficacy and accuracy by investigating an ACPN model of a wide area protection system for a typical power grid. The proposed modeling and analysis schemes may further provide a framework to help assure reliability and interoperability of diverse smart grid components.

• 한국운동역학회지
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• 제26권4호
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• pp.407-412
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• 2016

Objective: The aim of this study was to analyze the net joint moment and joint power of the lower extremity during squat in female patients with genu varum. Method: Eight female patients with genu varum were asked to do regular squats, and their net joint moment and joint power were compared to those of another eight female participants with straight legs. Their video recordings and ground reaction force data were analyzed to be used as a theoretical evidence of squatting effectively for female patients with genu varum. Results: Squats had a higher impact on internal knee joint rotation and ankle joint flexion moments in the genu varum group than in the straight leg group due to their weak and short hip joint muscles. Conclusion: There is a need to develop a squat movement that is appropriate for women with genu varum in order to distribute overload efficiently among the hip, knee, and ankle joints and to strengthen the muscles in a balanced way.

• 한국통신학회논문지
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• 제7권4호
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• pp.151-155
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• 1982

Petri net는 concurrent system을 model化하고 해석하기 위하여 사용되어져 왔으나 그 능력은 제한되어 있다. 따라서 본 논문에서는 model化능력을 향상시키기 위하여 禁止edge 및 容量을 부가해서 확장된 Petri net를 제안하였고 확장된 Petri net의 해석능력을 높이기 위하여 일반 petri net로 변환하는 알고리즘을 제안하였다. 또한 실례를 들어 설명함으로써 본 논문에서 제안한 알고리즘의 유용성을 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.657-659
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• 1997

발전설비를 안정적이고도 효율적으로 운용하기 위해서는 완벽한 감시기능을 갖추는 것이 필수적이다. 발전소에 설치된 Bailey사 제품의 Infi-90 시스템은 발전소 제어 및 데이터로깅까지 컴퓨터를 사용하지 않고도 할 수 있는 폭넓은 응용 범위를 가지며, 몇 개의 루프로 구성된 소규모 계장에서부터 대규모 계장에까지 적용할 수 있는 확장성이 큰 시스템이다. 본 논문에서는 Infi-90 시스템에서 제공하는 접속장치를 활용하여, PC를 이용한 데이터 모니터링시스템 개발에 관하여 논하고자 한다.