• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.155-162
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• 2007

Recently, retail store automation appliance market is changed with traditional POS systems techniques and RFID, radio POS system, and self checkout system, etc. in the foreign advanced distribution industry. Retailers and consumers require convenient POS system which can provide more functions and fast service. These requests bring to rapid evolution of various H/W and S/W corresponding with POS system. In this study with the POS systems and the RFID technology we develop core technology of movable u-POS system based on RFID that can use in large store. So we propose u-Cart system that can alternate the current shopping cart and POS terminal and that provide value added services to customer. As the result we present the configuration of u-Cart terminal device(WMDT : Wireless Mobile Data Terminal) including RFID reader module that can provide various information to consumer and some convenient client applications that are running in WMDT and u-POS administration service module.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.89-94
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• 2015

FMS which has a concept that wireless terminal can replace wire terminal services is a technologies that is can provide service costs same as wire terminal in the special zone. Enterprise type of FMC that is developed making up for the weak point is must have to improve voice quality and FMC performance in the soft phone. This paper measure voice quality based on the one way of the total estimated delay time of FMC to carry out IMS services between IP-PBX and FMC soft-phone to operate it's controller optimally and put forward evidence to be in 120ms and 150ms in the VoIP FMC voice quality. To measure FMC performances in four categories evaluated trials and prove its performances.

• The KIPS Transactions:PartD
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• v.14D no.5
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• pp.565-572
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• 2007

In this paper, we developed a VoWLAN(Voice over WLAN) system based on an open source software. The system aims to provide VoIP service over wireless LAN with an IP-PBX server. The features of system presented in this paper are as follows. First, the initial cost for the development is reduced since the system is developed based on open source software. Second, the system provides various additional services such as Voice Mail, Conference Call, and Interactive Voice Response with a software IP-PBX server. Third, the VoWLAN terminal provides high-level user applications with minimal system resources using lightweight open software solutions. Finally, it is highly scalable since it is based on the open source software.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.117-130
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• 1999

In this paper, the performance of data communication function of military radio equipment P-999K is analyzed based on the standard CSMA/CA protocol which is DFWMAC standard protocol done by IEEE802.11 work group. Basic three standard protocols, i.e. Basic CSMA/CA, Stop & Wait ARQ and 4-Way Handshake CSMA/CA protocols are analyzed and compared with each other under the hidden terminal environment. The computer simulation is also done by using SIMSCRIPT II.5 which is popular software tool for an independent processing. The results show that p-persistent(with p=0.3) CSMA scheme is superior to non-persistent CSMA scheme with non-hidden terminal condition, but the performances of both schemes are almost same with hidden terminal situation. And the results of computer simulations are also showed that Basic CSMA/CA protocol is superior to the other protocols when the ratio of hidden terminals is below 10 % of total user population, however, with the above 20% hidden terminals environment and the higher offered traffic conditions the 4-Way Handshake CSMA/CA protocol shows the most superior performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.2
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• pp.238-246
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• 2024

Modern military operations rely heavily on broadband communication and data transmission. Recently, the rising use of intelligent unmanned technology necessitates more frequencies. Free-space optical(FSO) communication can offer high-data-rate communications with high security and no need for licensing. Therefore, the FSO communication holds significant interest and potential in the defense industry. In this paper, we present design of a FSO communication terminal taking Korean domestic weather conditions into account. The domestic atmospheric attenuation is analyzed using several models and two-year meteorological information for a city in Korea, and this analysis is utilized to design the FSO communication terminal. The design results were verified using an FSO communication test bed, and we achieved an Ethernet bandwidth of approximately 1.86 Gbps at a distance of 1.3 km with the optical amplifier output power of the test bed set to about 20 dBm.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.44-48
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• 2000

In this study was modify the PRMA for supporting various types of traffic classes such as CBR, VBR, ABR and UBR. For uplink, we use reservation slots and so the performance will not degrade in case of over load conditions. For downlink broadcasting slots for informing the status of slot reservations are used so the high priority priority terminal can preempt. And we use almost same size buffer as the frame size. So we can dynamically deal with, the traffic changes of VBR terminals. It makes easy for the terminals to reserve supplementary slots. Each terminal is reallocated by the priority of traffic classes and so we can easily select the dropping packets in case of overload conditions. As a result, using our scheme, we can get high channel efficiency and get low packet dropping ratio and delay.

• Annual Conference of KIPS
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• 2005.11a
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• pp.1263-1266
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• 2005

무선 인터넷 기술의 급성장에 따라 무선 인터넷의 이용 및 의존도가 높아지고 인터넷 사용자나 인터넷 서비스 제공자(ISP) 모두 안정된 서비스를 요구하고 있다. 이와 함께 전산 시스템 관리와 장애 예방 등의 데이터 보호도 중요한 요소가 되었다. 운용인력은 변동이 없는 반면 시스템 수는 크게 증가하면서 시스템을 체계적이고 효율적으로 관리하고 언제 어디서나 시스템 성능을 모니터링하고 운용되는 애플리케이션을 제어하고자 하는 사용자들이 증가하였다. 본 논문에서는 모바일 환경 하에서 원격지 터미널에 접속할 수 있는 MVTP(Mobile Virtual Terminal Protocol)을 구현하였다. 실험결과 시스템 관리자는 기존 메뉴기반 원격 관리 시스템에서 제공되지 않는 기능은 원격지 터미널에 접속 하여 관리할 수가 있고 무선 단말기를 통해 시간, 장소에 구애 받지 않고 시스템을 안전하게 관리할 수 있었다.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.95-96
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• 2006

A variety of systems have been attempted for effective urban management. In this paper, we introduce integrated urban management system (IUMS), which mainly consists of optical line terminal (OLT), optical network terminal (ONTs) and wireless access points (APs), by combining passive optical network (PON) and radio over fiber (RoF) technologies so as to take advantages of both two systems. Further, several IUMS services including disaster detection and prevention system (DDPS), bus information system (BIS) and real time location system (RTLS) are demonstrated in order to employ IUMS for the realization of future ubiquitous city (U-city).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.357-361
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• 1999

Currently, many research projects are focusing on automation of various equipment such as cranes and AGV's for automated container terminals. However, for more productivity of these terminals, integration of the required equipment is most crucial as proved in Computer Integrated Manufacturing (CIM). The integration requires information exchange via a type of network interconnecting various pisces of equipment. In order to better design such networks, this paper presents the requirements, available protocols, and basic network structure for an communication network in an automated crane terminal

• The Journal of Information Technology
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• v.8 no.1
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• pp.83-93
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• 2005

This paper again to present position of a bus that is running in bus government organization small grasp and Can instruct control about the vehicles progress speed in government organization small to bus driver. Therefore, Inform a bus that own wants to ordinary people who carry transfer communication terminal is situated to where present, ad Do by purpose that offer system that inform running information of a bus to ARS and FAX, internet and ordinary people through PC communication. Also, Intelligence style bus control system that see also includes function that do as can guide arrival expectation depot automatically without driver's manufacturing when run a bus.