• Proceedings of the Korea Association of Information Systems Conference
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• 2001.12a
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• pp.83-97
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• 2001

국내의 항만물류산업에서는 서류 전송을 합리화하고 입력데이터의 오류를 없애기 위해 EDI를 도입·실행하여 왔다. 그러나, 기존의 항만물류산업에서 사용중인 전통적인 EDI는 사내 정보시스템과의 비연계성, 과중한 EDI 구축비용과 소프트웨어 구입비 및 EDI 통신료, 산업간 EDI 자료교환의 불가능, 업무프로세스의 개선 미약, 응답시간의 지연, 사용의 불편성, 표준문서 사용 등 제반 문제점들이 미해결 상태로 남아있다. 차세대 인터넷 언어로 각광받고 있는 XML은 기존의 데이터를 보다 쉽게 표현, 교환, 저장할 수 있어서 무역, 금융, 멀티미디어, 전자상거래 등 다양한 분야에 응용되고 있다. 특히 XML의 개방적이고, 유연한 특징으로 인해 상이한 데이터 및 문서포맷을 지닌 다수의 거래업체간에 뛰어난 상호운영성을 가져와 이를 이용하는 비율이 급속도로 증가하고 있으며, 이를 위해 다수의 XML기반 프레임워크가 개발되어 적용되고 있다. 본 논문에서는 XML/EDl, BizTalk 프레임워크, ebXML 프레임워크를 항만물류산업의 EDI시스템에 적용하여 이들의 구조를 밝혀내고 각 프레임워크의 유효성을 검증하고자 시도하였다.

• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.520-534
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• 2003

In this paper, a performance evaluation model of the Fat-tree Network with the multiple-buffered crossbar switches is proposed and examined. Buffered switch technique is well known to solve the data collision problem of the switch network. The proposed evaluation model is developed by investigating the transfer patterns of data packets in a switch with output-buffers. Two important parameters of the network performance, throughput and delay, are then evaluated. The proposed model takes simple and primitive switch networks, i.e., no flow control and drop packet, to demonstrate analysis procedures clearly. It, however, can not only be applied to any other complicate modern switch networks that have intelligent flow control but also estimate the performance of any size networks with multiple-buffered switches. To validate the proposed analysis model, the simulation is carried out on the various sizes of Fat-tree networks that uses the multiple buffered crossbar switches. Less than 2% differences between analysis and simulation results are observed.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.2
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• pp.53-58
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• 2021

In this paper, an alternative finite memory structure(FMS) smoothing filter is developed for discrete-time state-space model with a control input. To obtain the FMS smoothing filter, unbiasedness will be required beforehand in addition to a performance criteria of minimum variance. The FMS smoothing filter is obtained by directly solving an optimization problem with the unbiasedness constraint using only finite measurements and inputs on the most recent window. The proposed FMS smoothing filter is shown to have intrinsic good properties such as deadbeat and time-invariance. In addition, the proposed FMS smoothing filter is shown to be equivalent to existing FMS filters according to the delay length between the measurement and the availability of its estimate. Finally, to verify intrinsic robustness of the proposed FMS smoothing filter, computer simulations are performed for a temporary model uncertainty. Simulation results show that the proposed FMS smoothing filter can be better than the standard FMS filter and Kalman filter.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.111-118
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• 2008

RIA(Rich Internet Application) has the best User Interface and easy way to use. It is used in many Application System and Web Application. This Paper introduces a RIA technology for Implementation of u-Hospital Application. This System uses a history of customers in the hospital and question about diseases, so we can improve the satisfaction of service. This paper shows that the u-Hospital System using RIA is more fast and easy than HTML application. Because RIA has special features that data can be obtained from server without reloading entire page and every user interaction does not require web server response. The proposed technology can improve the efficient u-Hospital System because it can be extended to ubiquitous mobile application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.655-662
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• 2016

Accurate stopping control is important for trains, especially now that many train stations are equipped with platform screen doors. Various algorithms have been proposed for accurate stopping control. However, most metro trains in South Korea use classic control algorithms such as PID control because other algorithms are too complex to realize. PID control has merits of simple structure and operation. However, PID control sometimes fails, and much time is needed to find the proper coefficients due to the long control period and the brake delay. We propose a control algorithm that uses a Kalman filter. The Kalman filter estimates the states at the time when braking starts. Then, a suitable control input is derived for proper control. System modeling and a computer simulation were performed with consideration of the brake properties and the period of the control system. The superiority of the proposed control algorithm is shown by analyzing stop errors.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.2
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• pp.17-25
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• 2003

In this paper, a processor architecture is proposed based on the state space implementation technique for real time processing of 2-D discrete wavelet transform(DWT). It conducts 2-D DWT operations in consideration of row and column direction simultaneously, thus can reduce latency due to memory access for storing intermediate results. It is a VLSI architecture suitable for real time processing. The proposed architecture includes only four multipliers and four adders, and NK-N internal memory storage, where K denotes the length of filter. It has a small hardware complexity. Therefore it is very suitable architecture for real time, embedded applications such as web camera server. Since the processor is easily extended to array structure, it can be applied to various image processing applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5A
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• pp.370-375
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• 2005

While the international standards bodies recommend the dual leaky buckets for the traffic specification for VBR service, video traffic shows burstiness in multiple time-scales. In order to fill this gap between the current standards and real traffic characteristics, we present a standard-compatible traffic parameter selection method based on the notion of a critical time scale (CTS). Since the defined algorithm minimizes the required link capacity under a maximum delay constraint, it could be used as a benchmark even when it can not be implemented easily. Simulation results with compressed video traces demonstrate the efficiency of the defined traffic parameter selection algorithm in resource allocation.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.3
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• pp.255-263
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• 2000

A multistage interconnection network is a suitable class of interconnection architecture for constructing large-scale multicomputers. Broadcast and multicast communication are fundamental in supporting collective communication operations such as reduction and barrier synchronization. In this paper, we propose a new multicast technique in wormhole-switched bidirectional multistage banyan networks for constructing large-scale multicomputers. To efficiently support broadcast and multicast with simple additional hardware without deadlock, we propose a two-phase multicast algorithm which takes only two transmissions to perform a broadcast and a multicast to an arbitrary number of desired destinations. We encode a header as a cube and adopt the most upper input link first scheme with periodic priority rotation as arbitration mechanism on contented output links. We coalesce the desired destination addresses into multiple number of cubes. And then, we evaluate the performance of the proposed algorithm by simulation. The proposed two-phase multicast algorithm makes a significant improvement in terms of latency. It is noticeable that the two-phase algorithm keeps broadcast latency as efficient as the multicast latency of fanout 2^m where m is the minimum integer satisfying $2^m{\geq} {\sqrt{N}}$ ( N is a network size).

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.5
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• pp.16-20
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• 1973

The most important thing in locating disturbances in optimal rapid traffic singnal control is to collect information cocerning toraffit flow by means of a detection method. In order to set up an optimal traffic singnal period, the analysis of a delay time phenomena in the signal period must also be considered. In fact, each of the distributed traffic quantities on the road are not similar factors in view of speeds and distances of succeeding cars. The causing factors are analyzed by the method of control engineering analysis, and they are coincident with disturbance. Thus distubances cause errors. Distubances are fuctions of time, and are classified into three conditions: Natural road state and weather are the first. The second is structures and function of vehicles, and the third is inducedbydrivers. This thesis deals with the last two cases except the first one for maximum utilization of the existing road state and weather conditions. The first condition remains constant, and then there exist some relations between vehicles and drivers. In the long run, it can be shown that the scheme for minimizing whole errors in the optimal traffic signal time setting is definitely presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8A
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• pp.1160-1168
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• 2000

This paper presents a real-time integrated traffic management (RITM) scheme that can effectively manage variable bit rate (VBR) and available bit rate (ABR) traffics having unpredictable characteristics in asynchronous transfer mode (ATM) networks. An unique feature of this scheme is that it has a special ATM cell control block which makes it possible to monitor bursty traffics in real-time so that the delay incurred to measure cell arrival rate is minimized. Additionally, the proposed scheme intends to dynamically reassign the leftover network resources to VBR/ABR connections without any deterioration in quality of service (QoS) of the existing connections. The RITM scheme has been verified to reliably monitor incoming traffics and to efficiently manage network resources by computer simulations. The capability of managing the incoming ATM traffics in real-time helps determine an optimal acceptable number of user connections for a given network condition. We can use this value as a threshold to protect the network from being congested and to find out a cost-effective buffer design method.