• IE interfaces
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• v.12 no.1
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• pp.56-67
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• 1999

This paper is about implementation issues for use of the Internet technology in education. An examination of the current status of virtual university provides guidance for subsequent prototype development. A virtual university is the Internet based process by which students increase their specific knowledge and skills via electronic interaction with content and people. Virtual university enables colleges and universities to provide students and faculty with network access to courseware and educational materials on multimedia servers free from time and geography constraints. In this paper, we present a prototype instruction support system (ISS). The ISS consists of the following components in architecture: Internet, software, hardware, database systems, users, and workflow. The ISS also assists several functions as follows: lecture notes, register processes, attendance checks, built-in boards, grading systems, questions and answers, electronic libraries, chats, and search engines. Our work will provide a guideline for the development of a virtual classroom for distance education and learning.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.551-555
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• 2014

In this paper, framework of weapon effects calculator for hardened targets is presented. Fast running time, validation and easy expandibility are required for weaponeering tools, and these requirements were met by using of physics-based fast-running models or semi-empirical equations for damage prediction and penetrations, and modular architecture. Key concepts and outputs, required functions and corresponding use cases were presented.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.3
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• pp.1-11
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• 1997

Since the radio spectrum is limited, future wireless system will have micro cellular architecture in order to provide multimedia traffic services on personal communicatons network. The small coverage area of micro cellular systems results in frequent hadnoffs and location updates. We focuse on network load and terminal power due to frequent location updates and propose a location tracking scheme using embedded-pager PCS terminals. The proposed scheme is expected to minimize theconsumption of PCS terminal powr and improve the receiving rate of callee because of the power saving mechanism and the embedded-pager PCS terminal. This paper proposes signaling flows among the network elements for the proposed location tracking scheme. The signaling flows are accomodated to not only the existed network architectures but alsothe ATM backbone network arcitecture. To verify the signaling flows, we used petri-Net model. The resutls show that the signaling flows are suitable to our proposed location tracking scheme.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.93-95
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• 2016

본 논문에서는 사물인터넷 서비스 모델인 OMA LWM2M 구조에서 IoT 게이트웨이가 포함된 확장 모델을 제안한다. 추가적으로 제안된 모델은 스마트폰 기반으로 구현된 IoT 게이트웨이를 가정하여 확장된 모델이다. 본 논문에서 제안하는 확장형 LWM2M 모델은 스마트폰을 이용하여 LWM2M 기반에서 스마트폰의 다양한 자원 및 None-LWM2M 클라이언트 자원을 LWM2M 자원 객체로 활용하여 다양한 IoT 서비스를 효율적이고 경제적으로 제공하는데 활용될 수 있다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.255-262
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• 1998

This paper presents a translation, rotation and scale invariant methodology for the recognition of closed planar shape images using the bispectrum of a contour sequence and the learning vector quantization(LVQ) neural classifier. The contour sequences obtained from the closed planar images represent the Euclidean distance between the centroid and all boundary pixels of the shape, and are related to the overall shape of the images. The higher order spectra based on third order cumulants is applied to tihs contour sample to extract fifteen bispectral feature vectors for each planar image. There feature vector, which are invariant to shape translation, rotation and scale transformation, can be used to represent two0dimensional planar images and are fed into a neural network classifier. The LVQ architecture is chosen as a neural classifier because the network is easy and fast to train, the structure is relatively simple. The experimental recognition processes with eight different hapes of aircraft images are presented to illustrate the high performance of this proposed method even the target images are significantly corrupted by noise.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.28-28
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• 2004

• Journal of Communications and Networks
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• v.6 no.2
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• pp.163-172
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• 2004

Ultra Wide Bandwidth (UWB) spread-spectrum techniques will playa key role in short range wireless connectivity supporting high bit rates availability and low power consumption. UWB can be used in the design of wireless local and personal area networks providing advanced integrated multimedia services to nomadic users within hot-spot areas. Thus the assessment of the possible interference caused by UWB devices on already existing narrowband and wideband systems is fundamental to ensure nonconflicting coexistence and, therefore, to guarantee acceptance of UWB technology worldwide. In this paper, we study the coexistence issues between an indoor UWB-based system (hot-spot) and outdoor point to point (PP) links and Fixed Wireless Access (FWA) systems operating in the 3.5 - 5.0 GHz frequency range. We consider a realistic UWB master/slave system architecture and we show through computer simulation, that in all practical cases UWB system can coexist with PP and FWA without causing any dangerous interference.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.1
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• pp.7-12
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• 2010

In this paper, we propose a new prioritized Optical Burst Switching (OBS) protocol based on a hop count, which can provide an efficient utilization in optical Wireless networks. Under several legacy schemes, a switch drops the burst with a shorter time among ones regardless of its traversed hop counts. As a result, the dropped burst that have been traversed more hops might cause to waste bandwidth than the one traversed a few hops. Noting that this problem, we propose the Just Enough Time (JET) with a hop count scheme which can reduce the wasted bandwidth by prioritizing the burst traversed more hops over others. From the simulation result, we show that the proposed scheme is advantageous over the legacy schemes in terms of the burst blocking probability and the link utilization.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.220-222
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• 2003

최근 무선 통신 기술의 발전으로 인해 무선 사용자를 대상으로 하는 멀티미디어 서비스가 보편화되고 있다. 그러나 무선 단말기의 제한된 능력으로 인해 유선 환경과 동일한 방식으로 무선 환경에서 서비스하는 경우, 이를 무선 단말기 상에서 유연하게 처리하기 어렵기 때문에 멀티미디어 데이터를 무선 단말기에 적합한 형태로 변환시킨 후 무선 사용자에게 전송해야 한다. 이에 따라 무선 사용자에게 효과적인 멀티미디어 서비스를 제공하기 위한 멀티미디어 오브젝트의 프레임 사이즈나 프레임 비율 등을 변환시키는 트랜스코딩 기법에 대한 연구가 현재 활발히 진행되고 있다. 본 논문에서는 트랜스코딩을 수행하는 프락시 간의 협동 구조를 바탕으로 사용자 이동성을 기반으로 한 멀티미디어 데이터 서비스의 구조적 효율성을 높이는 방식을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1401-1411
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• 1999

Due to the increase of multimedia services, multicasting is considered as important design factor for ATM switch. To resolve the traffic expansion problem that is occurred by multicast in multistage interconnection networks, this paper proposes the multicast switch using a high-speed bus and a shared memory switch. Since the proposed switch uses a high-speed time division bus as a connection medium and chooses a shared memory switch as a basic switch module, it provides good port scalability. The traffic arbitration scheme enables internal non-blocking. By simulation we proves a good performance in the data throughput and the cell delay.