• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.167-176
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• 2006

An minimum path algorithm for integrated networks with departure time constraints require considering arrival time of arriving mode, transfer time. waiting time, and departure time of next mode. Integrated network with diverse modes commonly include departure time constraints. Because public mode suck as train and airplane have fixed service schedule which provide passengers. This study developed the k-path algorithm in integrated network with time varying conditions and departure time constraints. We proposed the extended method based on entire path deletion method, and examined the application of the proposed algorithm through case study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.87-94
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• 2003

When faults occur in a distribution network, blackout loads must be restored as fast as possible to minimize interruption of electric service. This paper presents an expert system to restore distribution networks. The system is designed to minimize switching operations in a heuristic sense by using heuristic rules. The restoration process is converted to the feasible path finding problem in the state space of expert system by application of general topological knowledge base. Multiple load transfer algorithm is proposed to deal with complex situations.

• Transactions of Materials Processing
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• v.31 no.3
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• pp.143-150
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• 2022

The purpose of this study was to investigate an innovative hydroforming process for the cost-effective manufacturing of double layered tube with circumferentially corrugated patterns. Conventional double pipe heat exchanger has relatively poor heat transfer efficiency because of the limited contact area resulting from the concentrically arranged simple cylindrical structure. As a promising alternative to enhance heat transfer efficiency, double layered tube with corrugated internal pattern was considered in this study. To fabricate corrugated inner tube, innovative tube hydroforming system was developed. The customized loading paths were established using the simulated forming pressure and contracting stroke at various bar diameters. Experimentally obtained cross-sectional profiles were analyzed to evaluate the reliability and applicability of the hydroformed tube with various patterns. The results demonstrate that the proposed hydroforming process can be a feasible alternative for manufacturing high-performance double-tube heat exchangers.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.28-37
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• 2017

Multipath TCP (MPTCP), which is a layer 4 protocol that can get the reliability and the efficiency of the transmission by using multipath transfer, was standardized by the IETF. MPTCP provides superior performance when compared to a single TCP when used in a homogeneous network with similar network characteristics. However, MPTCP degrades performance when used in heterogeneous networks with different network characteristics. In this paper, we propose 'Delay-alerted path-blocking scheduler'. It measures the delay of each path and blocks the path with a long delay to reduce the order of packets in the receive buffer. If the duplicated packet is sent to the blocked path to measure the delay and the congestion on the blocking path is reduced, the blocked path is unblocked. For performance analysis, the proposed scheduler was implemented in the Linux kernel and improved performance was obtained in the test bed. We also confirmed that the proposed scheduler reduces the degradation of MPTCP performance in real wireless networks with heterogeneous path characteristics.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.8
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• pp.949-956
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• 1999

이 논문에서는 ATM (Asynchronous Transfer Mode) 방식의 초고속망의 장애 발생 시 이용자 연결의 QoS (Quality of Service)를 고려하여 복구할 수 있게 하는 보호 망 설계 방안을 제시한다. 제시한 설계 방안에 기초한 비용과 복구 특성을 분석과 모의 실험을 통해 알아본다. 제안하는 망에서의 복구는 분리 VP 그룹 (Disjoint Virtual Path Group, DVPG) 을 사용하는 상태 독립적 (State- independent) 방식으로 복구된다. ATM 망의 운용 및 보호 VP 할당과 용량 배정 문제를 정의하고 이를 바탕으로 최소의 비용을 갖는 VP 망을 설계한다. 망의 고장 시 기존 노드간의 VP 연결은 미리 할당된 링크 또는 노드 분리 보호 VP 경로를 따라 간단한 복구 알고리즘에 의해 빠르게 복구된다. QoS의 고려는 추가 비용을 필요로 하지만 정확한 이용자 연결의 복구를 실현하며, 분리 VP 그룹의 적용은 비용을 상승시키지만, 빠른 복구와 복수의 고장에 대처할 수 있는 방안이 된다.Abstract A cost evaluation of protection scheme for VP-based ATM network is presented here and its related characteristics are evaluated. The proposed and evaluated scheme is a state-independent restoration scheme using a disjoint path group. For fast and simple restoration of failed connections, link disjoint or node disjoint VP groups (DVPG) were utilized in this paper. A VP assignment and capacity planning problem is formulated. When failure occurs, the failed working VPs are switched to the protection VPs of disjoint path groups with a simple restoration scheme. And, cost evaluation and restoration characteristics are presented. The consideration of multiple QoS (Quality of Service) levels and disjoint path group protection scheme require additional network cost but acquire fit and fast restoration.

• Convergence Security Journal
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• v.15 no.2
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• pp.63-68
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• 2015

Current ICT(Information & Communication Technology) infrastructures (Internet and server/client communication) are struggling for a wide variety of devices, services, and business and technology evolution. Cloud computing originated simply to request and execute the desired operation from the network of clouds. It means that an IT resource that provides a service using the Internet technology. It is getting the most attention in today's IT trends. In the distributed cloud environments, management costs for the network and computing resources are solved fundamentally through the integrated management system. It can increase the cost savings to solve the traffic explosion problem of core network via a distributed Micro DC. However, traditional flooding methods may cause a lot of traffic due to transfer to all the neighbor DCs. Restricted Path Flooding algorithms have been proposed for this purpose. In large networks, there is still the disadvantage that may occur traffic. In this paper, we developed Lightweight Path Flooding algorithm to improve existing flooding algorithm using hop count restriction.

• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.6-12
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• 2010

In this paper a cross layer protocol, referred to as an underwater ad-hoc communication (UAC) protocol, is proposed for underwater acoustic networks (UANets). An underwater node (UN), which tries to transfer data to another UN or a buoy in ad-hoc manner, can access channel as well as determine routing path by employing the UAC protocol. The channel access, route determination, and reliable data transfer are designed being adaptive to underwater environments. In addition, we propose both UN and packet architectures in order to efficiently implement the UAC protocol for UANets.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.14 no.1
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• pp.24-31
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• 2018

The mechanical design procedure is studied for the PCHE(printed circuit heat exchanger) with electrochemical etched flow channels. The effective heat transfer plates of PCHE are assembled by diffusion bonding to make a module. PCHE is widely used for industrial applications due to its compactness, cost efficiency, and serviceability at high pressure and/or temperature conditions. The limitations and technical barriers of PCHE are investigated for application to nuclear components. Rules for design and fabrication of PCHE are specified in ASME Section VIII but not in ASME Section III of nuclear components. Therefore, the calculation procedure of key dimensions of PCHE is defined based on ASME section VIII. The effective heat transfer region of PCHE is defined by several key dimensions such as the flow channel radius, edge width, wall thickness, and ridge width. The mechanical design procedure of key dimensions was incorporated into a program for easy use in the PCHE design. The effect of assumptions used in the key dimension calculation on stress values is numerically investigated. A comparative analysis is done by comparing finite element analysis results for the semi-circular flow channels with the formula based sizing calculation assuming rectangular cross sections.

• Convergence Security Journal
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• v.13 no.4
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• pp.109-115
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• 2013

Security threats through e-mail service, a representative tool to convey information on the internet, are on the sharp rise. The security threats are made in the path where malicious codes are inserted into documents files attached and infect users' systems by taking advantage of the weak points of relevant application programs. Therefore, to block infection of camouflaged malicious codes in the course of file transfer, this work proposed an integrity-checking and behavior-based detection system using File Transfer System (FTS), logical network partition, and conducted a comparison analysis with the conventional security techniques.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.7
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• pp.361-370
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• 2016

Effective acquisition technology is an important factor determining the competitiveness of companies(Roxas et al., 2011). Since the importance of technology transfer has been increased, there has been a growing interest in company, government, university and research institutes (Bozeman et al., 2015). Despite the national efforts for activating technology transfer, a lot of technology is still in universities and R&D center(Ockwell et al., 2009). The barriers of technology transfer are a main reason to inhibit the technology transfer. In order to be lower technology transfer barriers, it is necessary to derive the technology transfer broker based on social network analysis. However, most studies related to technology transfer broker had been focused on empirical study(Bozeman et al., 2015). Therefore, it is needed to suggest the method to grasp the opportunity that can lead to technology innovation based on analyzing and visualizing the network of technology transfer. The method in this study provides the company with the connectable path, technology transfer broker and strategy to classify the technology actor within the network. Finally, the method is applied to Global MVP for verifying the feasibility of method.