• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.199-206
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• 2015

A rising attention is paid to the railway system in many countries. KOREA is also of the opinion that the railway has to play a more important role in the near future to face up to the problems that increase gradually in the transport sector. To attract more traffic to the rail networks, it is important for rail modes to have running time competitiveness. Tilting trains, where it is possible to tilt the car-body towards the center of the curve, are a less expensive alternative to shorten travelling times on existing lines. Running time for tilting train is one of the most important factors, with which passenger demand forecasting or economic feasibility analysis will be done. This paper evaluates the speed limitation of tilting train around curves and also presents calculation process of its simulated possible running time. Then the adequacy of estimated time is verified with running time for Korean protype tilting train TTX (Tilting Train eXpress) by actual test run. As a case study, the estimated running time for the production version of tilting train and its time saving are presented compared with 2012's conventional Saemaul trains and non-tilting trains on the Gyeongbu line in the Korean rail network.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.326-334
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• 2016

In this paper for developing and implementing the realtime HD level video streaming transmitter which is operated on the multi-platform in all network and client environment compared to the exist video live streaming transmitter. We design the realtime HD level video streaming transmitter supporting the multi-platform using the TMS320DM386 video processor of T.I company and then porting the Linux kernel 2.6.29 and implementing the RTSP(Real Time Streaming Protocol)/RTP(Real Time Transport Protocol), HLS(Http Live Streaming), RTMP(Real Time Messaging Protocol) that can support the multi-platform of video stream protocol of the received equipments (smart phone, tablet PC, notebook etc.). For proving the performance of developed video streaming transmitter, we make the testing environment for testing the performance of streaming transmitter using the notebook, iPad, android Phone, and then analysis the received video in the client displayer. In this paper, we suggest the developed the Realtime HD(High Definition) level Video Streaming transmitter performance data values higher than the exist products.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.47-54
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• 2008

In order to realize Intelligent Transport System (ITS) without any road facilities support, Inter-vehicle Communication (IVC) is increased attention. IVC makes it possible to exchange real-time information among vehicles without centralized infrastructure. The IVC systems use multi-hop broadcast to disseminate information. In this paper, we propose the improved AODV routing protocol based on location information. The proposed AODV routing protocol transmits Hello packet with location information to calculate the distance between nodes. Then it achieves fast link recovery. We confirm the throughput performance of the proposed AODV routing protocol compared with the AODV routing protocol using Qualnet ver.3.8 simulator.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.59-65
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• 2010

This paper proposes an implementation of a hardware module for transmitting MPEG-2 TS data over the internet protocol (IP)-based network. This implementation consists of two modules; one is an encapsulation module which bridges between n TS packets, where $1\;{\leq}\;n\;{\leq}\;7$, and an IP packets, the other is a packet conversion module which extracts an DSM-CC PS packet from consecutive TS packets and then reconstructing an IP packet. So, these IP packets are carried over 150 megabits per second. Although overall work flow of the proposed DeMUX is based on the reference design of ALTERA, the DeMUX is enhanced by modifying it and performs more functions by adding a packet conversion module. The DeMUX is described by Verilog-HDL (hardware description language) and shows the faithful functionality and throughput through the simulation.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.2
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• pp.13-29
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• 1997

This paper considers a new routing problem, successive max-min connection ratio problem (SMCRP), arised in circuit telecommunication networks such as SONET and WDM optical transport network. An optimization model for SMCRP is established based on link-flow formulation. It's first optimization process is an integral version of maximum concurrent flow problem. Integer condition does not give the same connection-ratio of each node-pair at an optimal solution any more. It is also an integral multi-commodity flow problem with fairness restriction. In order to guarantee fairness to every node-pair the minimum of connection ratios to demand is maximized. NP- hardness of SMCRP is proved and a heuristic algorithm with polynomial-time bound is developed for the problem. Augmenting path and rerouting flow are used for the algorithm. The heuristic algorithm is implemented and tested for networks of different sizes. The results are compared with those given by GAMS/OSL, a popular commercial solver for integer programming problem.n among ferrite-pearlite matrix, the increase in spheroidal ratio with increasing fatigue limitation, 90% had the highest, 14.3% increasing more then 70%, distribution range of fatigue.
ife was small in same stress level. (2) $\sqrt{area}_{max}$ of graphite can be used to predict fatigue limit of Ductile Cast Iron. The Statistical distribution of extreme values of $\sqrt{area}_{max}$ may be used as a guideline for the control of inclusion size in the steelmaking.

• The Journal of the Korea Contents Association
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• v.9 no.2
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• pp.60-66
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• 2009

In this paper, implementation of an ensemble transport interface (ETI) adapter for multimedia services based on terrestrial-digital multimedia broadcasting (T-DMB) is introduced. In general, ETI adapter should manipulate three functions: receiving packets packing multimedia data from service providers, configuring an ETI frame (G.703) from these data, and transmitting these frames to T-DMB multiplexer. To achieve these roles, the proposed ETI adapter consists of the network management module for data transmission and flow control between service providers and this adapter, the ETI configuration module for gathering data and then making ETI frames, and the hardware board for pushing ETI frames in real-time. The proposed adapter yielded faithful results without data lose on transmitting ETI frames to T-DMB multiplexer in the range of $64{\sim}1,153kbps$ specified in ETSI EN 300 401 after packing multimedia data received via Internet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.800-808
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• 2007

With the development of wireless data communication technology, all IP-based network will become compositions of wired and wireless networks. TCP is a connection-oriented, reliable transport protocol and has been used as de facto standard in most wired networks. Because TCP's congestion control algorithm could not distinguish congestion from BER, link failure and frequent route changes, TCP shows a poor performance over mobile ad-hoc networks. In this paper, the theoretical feature of TCP was studied and the performance of TCP over mobile ad-hoc networks was analyzed with ns2.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.6092-6115
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• 2017

This paper demonstrates a case for an end-to-end pure Application Security Layer for reliable and confidential communications within an Internet of Things (IoT) constrained environment. To provide a secure key exchange and to setup a secure data connection, Transport Layer Security (TLS) is used, which provides native protection against replay attacks. TLS along with digital signature can be used to achieve non-repudiation within app-to-app communications. This paper studies the use of TLS over the JavaScript Object Notation (JSON) via a The Constrained Application Protocol (CoAP) RESTful service to verify the hypothesis that in this way one can provide end-to-end communication flexibility and potentially retain identity information for repudiation. As a proof of concept, a prototype has been developed to simulate an IoT software client with the capability of hosting a CoAP RESTful service. The prototype studies data requests via a network client establishing a TLS over JSON session using a hosted CoAP RESTful service. To prove reputability and integrity of TLS JSON messages, JSON messages was intercepted and verified against simulated MITM attacks. The experimental results confirm that TLS over JSON works as hypothesised.

• International journal of advanced smart convergence
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• v.5 no.3
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• pp.61-65
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• 2016

In the TV broadcasting, movie production and business the transportation of video between creators (programmers, studios) and distributors (broadcast and cable networks, cable and satellites companies) is still a mix of File Transfer Protocol (FTP), physical delivery, and expensive multicast satellite. Cloud-based file sync-and-share providers like Dropbox and box are playing an increasing role, but the industry's unique demands for speed and multicasting have fueled the growth of IP Video transport. This paper gives a solid grasp of the major elements of IP video technology, including content preparation, system architecture alternatives and network performance management.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.193-202
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• 2015

The development of the security solutions that can provide a variety of security services is needed urgently. For development of the security solutions, analysis of international standard security technology is the key. In this paper, international organizations' standardization(ISO/IEC JTC1 SC27, ITU-T SG-17, IETF Security Area, etc.) and the current trend of the standard security technology are mainly analyzed. The core of the latest security technology(Application Bridging, DNS-based Authentication, HTTP Authentication, IP Security, Javascript Security, Authentication Technology Next Generation, Managed Incident, Web Authorization Protocol, Security Automation, Transport Layer Security, etc.) is analyzed focusing on 18 working groups of the IETF.