• Information and Communications Magazine
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• v.25 no.1
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• pp.69-73
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• 2008

본 논문은 차량간 통신을 활용한 ITS와 Telematics 서비스 구현 현황과 표준화 추진 현황에 대하여 기술한다. 차량간 통신의 개념과 일반적인 의미를 소개하고 유럽에서 진행중인 Car-to-Car Communication Consortium의 표준화 내용을 시스템 구조와 함께 소개한다. 또한 유럽에서 진행중인 차량 안전 기술 개발을 위한 PReVENT와 SAFESPOT 프로젝트 및 미국의 DIC 프로젝트와 일본의 ASV-3 프로젝트를 소개한다. 마지막으로 우리나라 TTA에서 추진하고 있는 차량간 통신 표준화현황을 기술하고 향후 우리의 표준화 방향을 제시한다.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2E
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• pp.61-66
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• 2005

Experimental work in underwater acoustic communications using passive phase conjugation has shown that the demodulation error depends on the relative drift rate between the source and receiver [Rouseff et al., IEEE J. Oceanic Eng. 26, 821-831 (2001)]. The observed effect involves the mismatch between the initial impulse response and the subsequent response after the source or receiver has changed locations. In the present work, the effect of drifting source is analyzed by numerical simulations and compared to the experimental results. The communications bit error rate is qualified as a function of drift rate, drifting direction, and source-receiver range.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.25 no.2 s.213
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• pp.49-53
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• 2007

• Journal of the Korean Society for Library and Information Science
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• v.24
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• pp.263-288
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• 1993

The use of telematics, or of data communications, for the information services is a much debated issue currently in the information science. The purpose' of this study is to gain a general overview of the use of data communications in specialized information centers in order to find out the direction of development in furture. In this study, the state of the specialized information services by data communications in Korea was analysed from the following points of view: (1) What kind of role play the liberalization of telecommunication to help develope the specialized information services? (2) Which problems have happend to the specialized information services using data communications? (3) How are technical, economical, and methodical problems handled for the new services? The background research stems from interview with managers and researchers in 5 specialized information centers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1843-1850
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• 2004

If the location information of a great number of cars kept for business with telematics terminals is acquired and managed efficiently, this information forms the foundation for controlling cars and traffic flows. The studies on the pure spatial indices have focused on the efficient retrievals. However, the acquisition and management of the terminal location of moving objects are more important than the efficiency of the query processing in the moving object databases. Therefore, it will be need to adopt parallel processing system for the moving object databases which should maintain the object's current location as precise as possible. This paper proposes a location management system using CDMA communications of telematics terminals. More precisely, we propose a architecture of spatial indexing mobile objects using multiple processors, and also newly propose a method of splitting buckets using the properties of moving objects in order to minimize the number of database updates. We also propose a acquisition method for gathering the location information of moving objects and passing the information of the bucket extents in order to reduce the amount of passed messages between processors.

• ETRI Journal
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• v.35 no.1
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• pp.7-17
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• 2013

The ongoing proliferation of new services, applications, and contents is leading the Internet to an architectural crisis owing to its inability to provide efficient solutions to new requirements. Clean-slate architectures for the future Internet offer a new approach to tackle current and future challenges. This proposal introduces a novel clean-slate architecture in which the TCP/IP protocol stack is decoupled in basic functionalities, that is, atomic services (ASs). A negotiation protocol, which enables context-aware service discovery for providing adapted communications, is also specified. Then, we present how ASs can be discovered and composed according to requesters' requirements. In addition, a media service provisioning use case shows the benefits of our framework. Finally, a proof-of-concept implementation of the framework is described and analyzed. This paper describes the first clean-slate architecture aligned with the work done within the ISO/IEC Future Network working group.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.7
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• pp.9-18
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• 1997

In this paper, we implemented the communication module in the Telephone Network Access Subsystem(TNAS) of the Advanced Communications Processing System(ACPS). We defined some kinds of communication tasks and related resources like several queues which are executed in real-time operating system, and implemented the procedures for processing the user information. Through traffic modeling and simulation, the performance of the Service Processing board Assembly(SPA) is evaluated in the aspets of system utilization and buffer size. The ACPS should accommodate various public networks such as public switch telephone network, packet switchen data network, frame realy netork, and ATM network. The communications module proposed in this paper could be used inthe interface beween the SPA and the High Speed Network Adaptor of other network interface subsystems.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.11-20
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• 1997

It is a recent trend that mobile communications and PCS are intergrated into the broadband network. Broadband mutlimedia traffic will be transported over the integrated network. In this paper, we propose a connection re-routing method for fast inter-switch hadoffs and dynamic resurce reservation scheme, which is based on the proposed re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing, the proposed re-routing method is to reserve VPI/VCIs for possible inter-swich handoff calls in advance. Our reservation scheme is to statistically reserve the fixed resources for possible inter-switch handoff calls, according to the QoS of the handoff calls. The simmulation reslts show that our proposed scheme satisfies the required QoS of handoff calls and keep the dropping probability of handoff calls lower than other schemes.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.93-99
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• 1998

The chirping characteristics of InGaAsP electroabsorption modulatiors have been analyzed. The effective .alpha. parameters for large signal modulation were estimated by comparing the pulse shape after fiber transmission with constant chirping assumption.We investigated the structure and the operating condition of the modulator to improve the chirping characteristics. The .alpha. parameters were calculated as the function of wavelength detuning and the bias voltage. To minimize the chirping performance, high bias voltage and a small wavelength detuning and the bias voltage. To minimize the chirping performance, high bias voltage and a small wavelength detuning were preferred. An negative .alpha. value is achieved at the wavelength detuning below 30meV with a proper bias voltage so that pulse compression effect was expected.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.1
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• pp.14-21
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• 1979

This paper deals with tIne interface error in the on-line computer systems by using the FSK radio communications. The wideband frequency shrift keying method is used for briary data transmission between the remote terminals and the main computer. To mintmize the error rate In the decoder systems of the main computer, a synchronizing pulse is added to the frame, so that the phase In both receiver and transmitter are synchronized. When the information signal with a constant error bit is received through FSK, It is designed to use the microprocessor for calculation of error bit. As results, most bit error are caused in FSK radio communications. and a few error bit Is me - asured to enter the mirroprocessor from the input buffer.