• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1363-1366
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• 2002

The studies of multi-hop wireless networks are active as the new communication media, which does not require any fixed communication infrastructure. One of application of the networks is local information distribution service, which is useful far daily activities in certain geographically restricted region or community within a radius of several kilometers. In this paper, MID-Net, which is the network enabling such distribution service, and effective information distribution algorithm MCMS are proposed. The behavior of the MID-Net is characterized by the waiting time function, three types of the functions are proposed in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.243-245
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• 2005

This paper presents a wired and wireless linked remote control system. Ethernet based network communication is used for long distance management and 2.4GHz RF network is adopted for the local area communication between the main network and the ballast. For the effective remote control and management including dimming using wired and wireless linked digital communication networks, control circuit of the ballast is implemented with fully digital circuit using MCU and EPLD. In this paper, the proper frame structure is proposed for the digital-remote lighting-control system and the detailed system configurations including fully digital controlled ballast for the induction lamp are described.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2005년도 제4회 추계학술대회 및 정기총회
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• pp.83-88
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• 2005

A transportation problem in Korea is a serious issue that has to be solved urgently in the motor era of 15 million vehicles. Recently ITS has been introduced to improve efficiency of the current roads because an excessive budget and a long term construction are needed to build new roads. Therefore the government enacted the law as of ITS and the in architecture. However, these ITS information services were oriented to mainly vehicles and drivers, not public entities such as bus driver, passengers and so on. Nowadays lots of local autonomous city introduced a public transportation information system (PTIS), and providing useful information for the public. For this PTIS, important design issues are to be focused on detecting and tracking technology of moving bus, and a wireless communication link to transmit the location information. This paper presents design models using several wireless communication methods, and an implementation case using a Wireless packet Data communication Network (WDN) to transmit bus location information at Seoul, Korea.

• 한국해양공학회지
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• 제12권2호통권28호
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• pp.139-146
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• 1998

This paper introduces a network system for monitoring coastal oceanographic data. The network system consists of three parts such as the buoy to observe oceanographic data, the local site to collect data transferred from buoys, and the host site to construct the oceanographic data-base and to share the information for monitoring coastal oceanographic data. The buoy has a one-board microcomputer to manage and to acquire coastal environment data in real-time. A wireless and wire communication technique is employed in order to transfer data measured by buoys and to link local and host sites, respectively. In measuring coastal environment data, this system shows more cost-effective way than the presents conventional. In addition, the realtime monitoring system continuously from various sites with the network systems.

• 상하수도학회지
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• 제32권4호
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• pp.309-315
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• 2018

Currently, the commercialization of the $5^{th}$ Generation (5G) service is becoming more prevalent in domestic communication network technology. This has reduced communication delay time and enabled large-capacity data transmission and video streaming services in real-time. In order to keep pace with these developments, K-water has introduced a smart process control system in water purification plants to monitor the status of the water purification process. However, since wireless networks are based on the public Long Term Evolution (LTE) network, communication delay time remains high, and high-resolution video services are limited. This is because communication networks still have a closed structure due to expense and security issues. Therefore, with 5G in its current form, it is very difficult to accommodate future services without improving the infrastructure of its communication networks. In recognition of these problems, this study implemented the authentication and management function of wireless networks on a wired network management system in the K-water Bansong water purification plant. The results confirmed that wired Local Area Network (LAN) services give a higher security performance than an expensive commercial wireless LAN system. This was achieved by using an Internet Protocol (IP) address management system of wired networks and the packet filtering function of the Layer2 (L2) switch. This study also confirmed that it is possible to create a wireless LAN service that is 3.7 times faster than the existing LTE communication network.

• 대한디지털의료영상학회논문지
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• 제5권1호
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• pp.130-136
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• 2002

One of current trends of medical technology is analog to digital. Moreover, The Government put a premium on PACS(Picture Archiving and Communication System) for Medical Insurance in November, 1999. Therefore many hospitals are installing(or planning to install) PACS facilities on their buildings. However most of hospitals didn't consider PACS facilities in the beginning of construction. In particular, the Networking is one of the most difficult things for PACS installation. There is no space for network equipments, and no path for network lines, etc. To solve these problems, wireless network is proposed. The wireless network is divided to three parts mainly. One is the wireless communication for Local Area Network, another is the data transmission through a satellite for Tele-Radiology, and the last one is the technology using Bluetooth for each sub-system of PACS. But there are other problems in wireless systems, i.e., network bandwidth, system stability, interference with other devices. The purpose of this paper is to suggest the future and new trend of PACS including all the problems.

• 한국인터넷방송통신학회논문지
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• 제9권6호
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• pp.195-200
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• 2009

본 논문에서는 지방상수도에서 운영되고 있는 유선망을 무선랜방식의 Wi-Fi망으로 시범도입 하였고 현장 실증시험을 통해 신뢰성을 검증하였다. 도입된 무선통신망은 기존 유선통신망에 비해서 비용절감 및 고장점 감소를 통해 정성적 및 정량적으로 효과가 있음이 알 수 있었다. 이번 연구로 기존의 광역상수도와 현재 위 수탁 운영 중인 지방상수도 운영관리의 고도화를 위해 무선통신망이 도입 가능함을 입증할 수 있었다.

• 한국ITS학회 논문지
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• 제5권3호
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• pp.1-12
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• 2006

현재 각 지자체별로 ITS 시스템이 도입되고 있으며 대시민 서비스차원에서 버스정보시스템(BIS)이 우선적으로 도입, 운영되고 있다. 이러한 버스정보시스템의 대표적인 위치추적 및 무선통신방식으로 DSRC+DSRC방식, GPS+무선통신망, Beacon+Beacon이 각 지자체별 특성에 맞게 구축, 운영중에 있다. 지금까지 BIS 시스템에 대한 평가는 각 지자체별로 사전, 사후분석의 설문조사항목을 통해 정성적 평가만 수행되었으며 시스템의 성능에 대한 평가는 실시되지 않았다. 따라서 본, 논문은 현재까지의 시행하였던 BIS 시스템에 대한 평가방안을 기초로 성능평가를 포함한 새로운 평가방안을 수립하여 각 BIS 방식별 대표시스템을 선정, 도착정보 신뢰도와 무선통신성공율의 효과척도를 적용하여 해당 시스템의 신뢰도나 효율성에 대한 평가를 수행하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.549-551
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• 2002

A Wireless Local Area Network (WLAN) is a flexible data communication system implemented as an extension to, or as an alternative for, a wired LAN with in a building or campus. However, communications in an indoor environment present problems not encountered in outdoor wireless communication systems. Since cellular type systems are interference limited, the indoor environment is more hostile than the outdoor environment due to the lower propagation constant. In this paper, the equation for the signal to interference ratio in a multistory building will be derived. Knowing the S/I ratio, the floor frequency reuse can be determined. Finally, the simulation in this research is designed to study the performance (BER) of WLAN system in the multistory environment by applying the 8-PSK Trellis Coded modulation technique. The procedure allows a quick evaluation of BER in Wireless LAN system due to the co-channel interference.

• 한국해양공학회지
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• 제19권6호통권67호
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• pp.86-91
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• 2005

Regarding some of tire important works in tire shipyard, like tire production process, quality control, and material handling, there are many elements that disturb tire work-flaw. For example, there are mistakes in manufacturing, delay of production, and poor quality. These kinds of disturbances are from tire delay of communication time between tire production field and tire management. Therefore, it would be possible to strengthen tire competitiveness of shipbuilding industries by applying tire information technology based on Wireless Local Area Network (Wireless LAN), in order to establish tire multi-possession of real time production information in limited large shipbuilding yard. In this study, tire construction concept of tire information system, based on Wireless LAN, is proposed to build communication infrastructures in shipyards. The various information regarding shipbuilding inspection, process management, and material flaw are analyzed and constructed to databases in tire middle ware system, as tire platform for using Personal Display Agent (PDA). At last, tire middle ware system, which delivers tire information, is developed by tire C$\sharp$ and Microsoft.net; also, tire PDA application system is structured in WinCE O/S, and is tested and evaluated under tire server linked condition.