• Proceedings of the KSR Conference
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• 2009.05a
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• pp.900-904
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• 2009

The measurement of contact wire uplift in electric railway is one of the most test method to accept the maximum permitted speed of new vehicles or pantographs. The contact wire uplift can be measured for shot periods when pantograph is running in monitoring station. This paper describes the development of two different methods for contact uplift measurement using vision-based system and wireless online monitoring system. Our vision-based system employs a high-speed CMOS (Complementary Metal Oxide Semiconductor) camera with gigabit ethernet LAN. The development of a real-time remote monitoring system that acquires data from any kind of sensor to be transmitted by wireless communication from overhead line and structure at 25 kV to a computer in catenary system. The proposed two kind of different measurement systems to evaluation for dynamic uplift of overhead contact wire shows promising on-field applications for high speed train such as Korea Tilting Train (TTX) and Korea Train eXpress (KTX).

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1253-1258
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• 2004

A general idea of implementing and managing real-time control on the VDN for rail transit vehicles is presented. In particular, the virtual device network considered in this paper is composed of Ethernet as the data network and LonWorks network as the device (control) network. A LonWorks/IP web server was used as a gateway to realize peer to peer data communication on the virtual device networks. Experimental results are given to validate the suggested architecture.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2778-2780
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• 2000

MMI system for strip caster 2 is described. It has been developed as a PC-based MMI system whose data is collected from the VME-based control system by ETHERNET. MMI elements that mimic the caster and its utilities are designed by using commercial program. In order to implement the UDP/IP communication in MMI, UDP/IP manager program with DDE that is a intercommunication protocol in MS-window is developed and connected with MMI mimics. Operator commands in MMI system are carried out immediately in VME system and the responses are displayed on MMI system. The developed MMI system has been proven to be convenient and stable through the operation of the past 5 years.

• Electronics and Telecommunications Trends
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• v.17 no.4 s.76
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• pp.16-28
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• 2002

전세계적인 경기 침체에도 불구하고 벤처 캐피탈로부터 수억 달러의 투자 자금을 끌어 모아 2001년 한해 큰 주목을 받았던 메트로 이더넷 서비스 사업자들이 최근 주춤하고 있다. 메트로 이더넷 서비스 시장의 선두 주자였던 Yipes Communications가 2002년 3월 추가적인 투자 자금 모집 실패 및 재무 유동성 악화로 인하여 미국 법원에 파산 보호를 신청한 것을 비롯해, 이보다 앞서 또 다른 메트로 이더넷 서비스 사업자인 Sigma Networks도 불과 창업 1년 만에 문을 닫고 말았기 때문이다. 이로 인해 일각에서는 이제 메트로 이더넷 서비스 비즈니스 모델을 다시 제고해야 할 시점이라면서, 메트로 이더넷 서비스 사업자들도 결국 과거 CLEC들과 같은 전철을 밟게 되지는 않을까 우려하는 목소리가 높다. 이에 본 고에서는 메트로 이더넷 서비스 비즈니스 모델을 현재 시점에서 재조명하고, 최근 시장 현황 그리고 앞으로의 발전 전망에 대하여 간략하게 살펴보았다.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.9
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• pp.912-917
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• 2006

A strain gauge weight measuring instrumentation system was designed with RF sensor network facilities. In the sensor module system data conversion and a series of signal processing were totally equipped. 16 strain gauges are incoming sensors and each output of the strain gauge was amplified and filtered for proper analog signal processing. Several measuring instrumentation OP amps and general purposed OP amps were used. 12 bits A/D converters converted analog signals to digital bits and a PIC microprocessor controlled the 16 channels of strain gauges. RF RS232 modules were used for wireless communication between the PIC microprocessor and an Ethernet host far a remote sensor monitoring system development.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.8
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• pp.734-741
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• 2004

This paper presents a network based fire detection system using CAN, in order to evaluate feasibility of home automation protocol for smart home. In general, because a traditional fire detection system has an analog transmission method with 4-20mA current, it has several shortcomings such as weakness to noise. Hence, as an alternative to the traditional system, this paper presents the architecture of CAN based fire detection system and the design method of CAN communication network. Also, the performance of the suggested system is evaluated through an experimental testbed. Especially, CAN has several advantages such as low cost and easiness of implementation compared to Ethernet or ARCNET, which are low layer of BACNet. Therefore, if CAN is adopted as low layer of BACNet, the home automation system is implemented more effectively.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.695-698
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• 2000

The services such as real-time audio and video applications have become increasingly popular, especially over the Internet. Furthermore, as being commercialized those contents on the Internet require quality of service (QoS) support to ensure their performance. PPP is the best solution to of for those kinds of services. The reason why we want to employ PPP is this satisfies most of the requirements associated with remote connectivity to an NSP, such as IP address assignment, security, and AAA (authentication, authorization and accounting). In addition, since ISPs and corporations are familiar with PPP based connectivity, easy migration from existing ISP infrastructure is expected, if QoS is guaranteed. But so for PPP has had no field to ensure the quality of service. This article presents the solution by using some tunneling protocols and the draft [1] that proposed additional LCP option fields to negotiate QoS. To communicate each other, after negotiating those option fields, over various protocols such as ATM, Ethernet, and etc. tunneling protocol is used. Following sections will mention those briefly. And the service provision to offer the end-to-end communication with negotiated QoS will also be proposed.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.3
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• pp.59-68
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• 1998

This paper propose a hardware architecure of multimediasysgem for integrated processing of the multimedia data such as audio and video, and describes on the design and implementation of multimedia integrated processing Unit. The unit comprises most commonly needed multimedia processing function for computer-based video conference: audio-visual datacapture, playback, compression, decompression as well as interleaving/disinterleaving of compressed audio-visual data. The proposed architecture minimizes the CPU overhead that might be caused by multimedia data processing and assures the fluent data flow among system components. Also, this unit is tested and analyzed under the computer-based video conference to confirm the multimedia unit of proposed architecture using communication protocol and application software through Ethernet and FDDI (Fiber Distributed Data Interface) networks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.186-191
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• 2005

To provide fairness among different ONUs in EPON, the upstream channel remains idle for some time after OLT receives the buffer status from all ONUs every cycle, which decreases the utilization and increases the delay. To solve this deficiency, we present a new grant scheduling method. The method consists of dividing ONUs into several sets where OLT can schedule ONUs in one set while others will be transmitting their traffic. This method will better utilize the bandwidth of EPON. The numerical results show that the larger the number of ONU sets is the smaller the minimum overhead becomes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.271-275
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• 2006

In STP, network performance differs depending on topology configuration. Therefore, we need to configure right topology for the optimal efficiency of networking. This paper suggest the optimal topology configuration for efficient networking between ethernet switchs. It finds out the best topology configuration by calculation mathematical model which uses transmission time between root switch and other switchs in the same domain. And it also analysed performance difference on locations of root switch. Through the performance analysis, we could conclude that placing the root switch in the center is the most efficient.