• The Transactions of the Korean Institute of Electrical Engineers
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• 제31권10호
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• pp.93-100
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• 1982

This paper presents the optimum computational algorithm for the real time control of system voltage and reactive power on the basis of a improved search method. In particular, special emphasis has been placed on the speed up computation at the first phase, and on the selection of initial state to reduce the transmission losses in the second phase. For the real time control, the new computation is improved and the computation time is very much reduced. And also, this paper discusses the integrated control scheme of system voltage and reactive power from the viewpoint of hierarchical control pattern, and studes the combination of the optimum system operations and controls.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.855-857
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• 2011

In this paper, we proposed EEAR(Efficient Energy Alternative Routing). This is a method of selecting a backup node for path routing management. When some node disconnection on the path routing, using pre-selected backup node provides immediately recover the path recovery. When selecting a Step-Parents node on the path management, the node' s energy level and distance information are cared in context-awareness. This not only increased the system' s capacity cost effectively, but also reduce transmission power entire nodes consume energy. As a result, each node could efficiently management and improves the life time for mobile host and extends system coverage.

• Proceedings of the Korean Information Science Society Conference
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• 한국정보과학회 2001년도 봄 학술발표논문집 Vol.28 No.1 (A)
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• pp.178-180
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• 2001

인터넷은 가변적인 지연, 손실, 제한된 대역폭과 같은 특성을 가진다. 따라서, 인터넷상에서 전송된 비디오는 품질을 보장받지 못한다. H.261, H.263과 같은 진보된 비디오 압축 표준은 제한된 대역폭의 인터넷에서 비디오 전송을 가능하게 한다. 이러한 압축 표준들은 움직임 예측.보상기법을 사용하여 압축된 프레임들은 시간적인 연관성을 가지게 된다. 따라서, 인터넷에서의 패킷 손실은 해당 프레임에 오류를 발생시킬 뿐만 아니라, 오류는 손실되지 않은 이후의 복원된 프레임으로 전파되어 비디오의 품질을 심각하게 떨어뜨린다. 기존에 연구된 오류 전파 방지 기법에는 NEWPRED, Error Tracking(ET), Intra-refreshment가 있고, 패킷 손실 복구 기법에는 재전송 기법과 FEC등이 있다. 그러나 비디오의 전체적인 품질을 향상시키기 위해서는 오류 전파 방지와 손실 복구가 병행되어야 한다. 따라서 본 논문에서는 인터넷을 통한 대화식 비디오를 전송하는 데 있어서 품질을 향상시키기 위해 손실 자체를 복구할 수 있는 FEC기법에 기반 하면서 참조 프레임 선택(Reference Picture Selection)을 이용하여 패킷 손실에 의한 오류 전파를 방지하는 기법을 제안한다. 실험은 제안된 비디오 오류 제어 기법이 FEC기법과 RPS기법의 장점을 살리면서 단점을 서로 보완하여 비디오의 높은 품질을 유지함을 보인다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.321-323
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• 2003

Maximum short circuit current of modern power system is becoming so large that the current should transmission capability. Although there are various kinds of method to solve this, approached from super conductivity Fault Current Limiter application viewpoint among them. High Temperature Superconductor-Fault Current Limiter(HTS-FCL) development is progressing according to HTS technology development, and system application is tried. For actual system application of such super conductivity FCL, an efficient method to find FCL locations suitable for reduction of short circuit currents of more than one fault location is developed.

• Proceedings of the KIEE Conference
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.240-242
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• 2004

Maximum short circuit current of modern power system is becoming so large that the current should transmission capability. Although there are various kinds of method to solve this, approached from super conductivity Fault Current Limiter application viewpoint among them. High Temperature Superconductor-Fault Current Limiter (HTS-FCL) development is progressing according to HTS technology development, and system application is tried. For actual system application of such super conductivity FCL, an more efficient method was developed to find suitable FCL application locations using sensitivity factor comparing previous paper.

• Annual Conference of KIPS
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• 한국정보처리학회 2012년도 춘계학술발표대회
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• pp.1021-1023
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• 2012

본 논문에서는 UWB 기술 기반 WiMedia Distributed Medium Access Control (D-MAC) 표준 프로토콜에 적용할 수 있는 Satisfaction of QoS (SoQ) 기반 협력 통신 프로토콜을 제안한다. 이를 위해 UWB 링크 전송 속도와 QoS 척도에 따른 릴레이 노드 선정 알고리즘을 제안한다. 본 논문에서 제안하는 SoQ 기반 협력 통신 프로토콜은 분산적인 D-MAC 표준 기술과 호환성을 갖고, 각 디바이스에서 독립적으로 실행되는 SoQ 기반 Relay Node Selection (RNS) 기준에 따라 실행된다.

• ETRI Journal
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• 제44권2호
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• pp.194-207
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• 2022

In the last decade, substantial progress has been achieved in intelligent traffic control technologies to overcome consistent difficulties of traffic congestion and its adverse effect on smart cities. Edge computing is one such advanced progress facilitating real-time data transmission among vehicles and roadside units to mitigate congestion. An edge computing-based deep reinforcement learning system is demonstrated in this study that appropriately designs a multiobjective reward function for optimizing different objectives. The system seeks to overcome the challenge of evaluating actions with a simple numerical reward. The selection of reward functions has a significant impact on agents' ability to acquire the ideal behavior for managing multiple traffic signals in a large-scale road network. To ascertain effective reward functions, the agent is trained withusing the proximal policy optimization method in several deep neural network models, including the state-of-the-art transformer network. The system is verified using both hypothetical scenarios and real-world traffic maps. The comprehensive simulation outcomes demonstrate the potency of the suggested reward functions.

• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.285-291
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• 2022

WSN is the major component for information transfer in IoT environments. Source Location Privacy (SLP) has attracted attention in WSN environments. Effective SLP can avoid adversaries to backtrack and capture source nodes. This work presents a Two-Level Randomized Sector-based Routing (TLRSR) model to ensure SLP in wireless environments. Sector creation is the initial process, where the nodes in the network are grouped into defined sectors. The first level routing process identifies sector-based route to the destination node, which is performed by Ant Colony Optimization (ACO). The second level performs route extraction, which identifies the actual nodes for transmission. The route extraction is randomized and is performed using Simulated Annealing. This process is distributed between the nodes, hence ensures even charge depletion across the network. Randomized node selection process ensures SLP and also avoids depletion of certain specific nodes, resulting in increased network lifetime. Experiments and comparisons indicate faster route detection and optimal paths by the TLRSR model.

• Mycobiology
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• 제51권6호
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• pp.463-467
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• 2023

Soybean is one of the world's most widely cultivated food crops, and soybean seeds are supplied from national seed resources in Korea. However, the transmission of seed-borne diseases through infected soybean seeds is problematic. Among these diseases, soybean seed decay is caused by Diaporthe spp. Infecting the pods, and the infected seeds show rotting symptoms. Most diseased seeds are removed during the selection process; however, it is difficult to distinguish infected seeds that do not display symptoms. Hence, a sequencebased method was devised to screen Diaporthe-infected seeds. Based on the nuclear ribosomal internal transcribe spacer (ITS) region of the pathogen, a primer was designed to distinguish the infection from other soybean seed pathogens. As a result of the comparison between healthy and Diaporthe-diseased seeds by using the primers, Diaporthe was detected only in the diseased seeds. Therefore, it is possible to distribute healthy soybean seeds by detecting Diaporthe-diseased seeds at the genetic level using the Diaporthe-specific primers.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제26권10호
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• pp.1517-1524
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• 2022

In this paper, we consider a heterogeneous network (HetNet) consisting of one macro base station and multiple small base stations, and assume the coordinated multi-point transmission between the base stations. In addition, we assume that the channel between the base station and the user consists of path loss and Rayleigh fading. Under these assumptions, we present the energy efficiency (EE) achievable by the user for a given base station and we formulate an optimization problem of dynamic cell selection and transmit power allocation to maximize the total EE of the HetNet. In this paper, we propose an unsupervised deep learning method to solve the optimization problem. The proposed deep learning-based scheme can provide high EE while having low complexity compared to the conventional iterative convergence methods. Through the simulation, we show that the proposed dynamic cell selection scheme provides higher EE performance than the maximum signal-to-interference-plus-noise ratio scheme and the Lagrangian dual decomposition scheme, and the proposed transmit power allocation scheme provides the similar performance to the trust region interior point method which can achieve the maximum EE.