• Spatial Information Research
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• v.21 no.3
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• pp.11-19
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• 2013

Compared with traditional video monitoring systems that provide a video-recording function as a main service, an intelligent video monitoring system is capable of extracting/tracking objects and detecting events such as car accidents, traffic congestion, pedestrian detection, and so on. Thus, the object tracking is an essential function for various intelligent video monitoring and surveillance systems. In this paper, we propose a background and local histogram-based object tracking approach for intelligent video monitoring systems. For robust object tracking in a live situation, the result of optical flow and local histogram verification are combined with the result of background subtraction. In the proposed approach, local histogram verification allows the system to track target objects more reliably when the local histogram of LK position is not similar to the previous histogram. Experimental results are provided to show the proposed tracking algorithm is robust in object occlusion and scale change situation.

• The Journal of Society for e-Business Studies
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• v.14 no.4
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• pp.315-332
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• 2009

In logistic environments, a process, in that it manages the flow of materials among partners, involves more than one organization. In this regard, a logistic process, as a combined process consisting of multiple sub processes, needs to be managed with controling interaction among partners. In achieving systematic management of a logistic process, traditional Business Process Management (BPM) cannot be used for the entire flow, since it lacks the ability to manage interactions among partners. Particularly in logistic environments where RFID technologies are used, how to deal with the connection between RFID event and logistic flow has not been properly addressed. To overcome this limitation, this paper proposes a new method of managing multi-organizational logistic processes based on RFID events. We define inter-workflow pattern, and suggest ECA(Event-Condition-Action) rules for auto triggering of logistic processes. To adjust the rules to RFID events, we invent RFID-based ECA rules using complex event. A prototype system has been developed for the purpose of demonstrating the effectiveness of our approach.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.6
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• pp.58-64
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• 2009

For the success of the reconfigurable computing, the algorithm for mapping operations onto coarse-grained reconfigurable architecture is very important. This paper proposes a resource-aware mapping system for the coarse-grained reconfigurable architecture and its own underlying heuristic algorithm. The operation assignment and the routing path allocation are simultaneously performed with a cycle-accurate time-exclusive resource model. The proposed algorithm minimizes the communication resource usage and the global memory access with the list scheduling heuristic. The operation to be mapped are prioritized with general properties of data flow. The evaluations of the proposed algorithm show that the performance is significantly enhanced in several benchmark applications.

• Smart Media Journal
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• v.4 no.4
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• pp.24-32
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• 2015

Recently, SDN is actively used as datacenter networks and gradually increase its applied areas. Along with this change of networking environment, research of deploying network security systems on SDN becomes highlighted. Especially, systems for detecting network flooding attacks by monitoring every packets through ports of OpenFlow switches have been proposed. However, because of the centralized management of a SDN controller which manage multiple switches, it may be substantial overhead that the attack detection system continuously monitors all the flows. In this paper, a sampling based network flooding attack detection and prevention system is proposed to reduce the overhead of monitoring packets and to achieve reasonable functionality of attack detection and prevention. The proposed system periodically takes sample packets of network flows with the given sampling conditions, analyzes the sampled packets to detect network flooding attacks, and block the attack flows actively by managing the flow entries in OpenFlow switches. As network traffic sampler, sFlow agent is used, and snort, an opensource IDS, is used to detect network flooding attack from the sampled packets. For active prevention of the detected attacks, an OpenDaylight application is developed and applied. The proposed system is evaluated on the local testbed composed with multiple OVSes (Open Virtual Switch), and the performance and overhead of the proposed system under various sampling condition is analyzed.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.618-631
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• 2017

In this paper, we propose a modification of fuzzy logic based DASH adaptation algorithm(FDASH) for seamless media service in time-varying network conditions. The proposed algorithm selects more appropriate bit-rate for the next segment by the modification of the Fuzzy Logic Controller(FLC) and reduces the number of video bit-rate changes by applying Segment Bit-rate Filtering Module(SBFM). Also, we apply the Start Mechanism for clients not to watch the low quality videos in the very beginning stage of streaming service and add the Sleeping Mechanism to avoid any buffer overflow expected. Ultimately, we verified by using NS-3 Network Simulator that the proposed method shows better performance compared to FDASH. According to the experimental results, there is no buffer underflow/overflow within the limited buffer size, which is not guaranteed in FDASH on the other hand. Also, we confirmed that mFDASH has almost the same level of average video quality against FDASH and reduces about 50% of number of video bit-rate changes compared to FDASH in Point-to-Point network and Wi-Fi network.

• Journal of KIISE
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• v.43 no.12
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• pp.1404-1411
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• 2016

Network virtualization is a technique that abstracts the physical network to provide multiple virtual networks to users. Virtualized network has the advantage to offer flexible services and improve resource utilization. In SDN architecture, network hypervisor serves to virtualize the network through address virtualization, topology virtualization and policy virtualization. Among them, address virtualization refers to the technique that provides an independent address space for each virtual network. Previous work divided the physical address space, and assigned an individual division to each virtual network. Each virtual address is then mapped one-to-one to a physical address. However, this approach requires a lot of flow entries, thus making it disadvantageous. Since SDN switches use TCAM (Ternary Contents Addressable Memory) for the flow table, it is very important to reduce the number of flow entries in the aspect of cost and scalability. In this paper, we propose a LISP based address virtualization, which separates address spaces for the physical and virtual addresses and transmits packet through tunneling, in order to resolve the limitation of the previous studies. By implementing a prototype, we show that the proposed scheme provides better scalability.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.6
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• pp.535-541
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• 2008

As the concurrent engineering concept has emerged along with the support of optimization techniques, lots of endeavors have been made to apply optimization techniques to actual design problems for a holistic decision. Even if the range of design problems which the optimization is applicable to has been extended, most of ship designs still remain in an iterative approach due to the difficulties of seamless integration of all related design activities. In this approach, an entire design problem is divided into many sub-problems and carried out by many different disciplines through complicated internal interactions. This paper focuses on preliminary ship design process. This paper proposes a process centric integrated framework as the first step to establish a workflow based design process management system. The framework consists of two parts; a schedule management part to support a manager to monitor current progress status and adjust current schedule, and a process management part to assist a design to effectively perform a series of design activities by following a predefined procedure. Overall system are decomposed into modules according to the target to be managed in each module. Appropriate interactions between the decomposed modules are designed to achieve a consistency of the entire system. Design process model is also designed on a thorough analysis of actual ship design practice. The proposed framework will be embodied using a commercial workflow package.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1976-1985
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• 2015

The amount of packets in palyout buffer of video streaming receiver can be changed by network condition, and saturated and exhausted by the delay and jitter. Especially, if the amount of incoming video traffic exceeds the maximum allowed playout buffer, buffer overflow problem can be generated. It makes the deterioration of video image and the discontinuity of playout by skip phenomenon. Also, if the incoming packets are delayed by network confusion, the stop phenomenon of video image is made by buffering due to buffer underflow problem. To solve these problems, this paper proposes the video streaming receiver with token bucket scheme which automatically establishes the important parameters like token generation rate r and bucket maximum capacity c adapting to the pattern of video packets. The simulation results using network simulator-2 (NS-2) and joint scalable video model (JSVM) show that the proposed token bucket scheme with automatic establishment parameter provides better performance than the existing token bucket scheme with manual establishment parameter in terms of the generation number of overflow and underflow, packer loss rate, and peak signal to noise ratio (PSNR) in three test video sequences.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.6
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• pp.644-661
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• 1999

인터넷에서 통합서비스를 제공하기 위해서는 종단간 다양한 QoS를 지원해야 하는데 이를 위해서는 인터넷뿐 아니라 종단 사용자와 인터넷을 연결하는 랜에서의 QoS 지원이 필요하다. 이에, IETF는 특정 링크 계층으로 구성되는 서브넷에서 QoS 지원을 위한 기본 골격을 제안하였다. 그런데 , 매체 접근방식에 따라 서브넷이 제공할 수 있는 서비스의 정도가 크게 달라지기 때문에 실제로 IS802 모델을 특정서브넷에 구현하기 위해서는 이에 대한 고려가 필요하다. 본 논문에서는 통합서비스를 지원하기 위한 기반이 되는 서브넷 차원에서의 우선순위 지원을 목표로 IS802 모델을 전통적인 이더넷과 토큰링에 적용하여 보았다. 먼저, IS802 모델의 대역폭관리자를 적용한 이더넷 IS모델과 토큰링_IS 모델의 구현을 제안하고 특별히, 이더넷의 경우 매체 접근 방식의 특성상 IS802 모델의 적용만으로는 서브넷차원에서의 우선순위에 따른 전송을 지원할 수 없기 때문에 이를 보완하기 위한 페이즈 모델을 추가로 제안하였다. 시뮬레이션을 통해 기존의 전통적인 이더넷과 토큰링 및 새롭게 표준화된 IS802 모델을 적용한 이더넷 _IS와 토큰링 _IS, 그리고 페이즈 모델간의 성능을 비교하였다. 시뮬레이션결과 토큰링의 경우 단순한 입장 제어에 의해서도 QoS 지원 정도가 크게 향상될수 있음을 볼 수 있었다. 또한 , 페이즈 모델의 경우 이더넷의 매체 접근 방식을 상당히 보완함으로써 QoS 지원 정도가 크게 향상될 수 있음을 볼 수 있었다. 또한, 페이즈 모델의 경우 이더넷의 매체 접근 방식을 상당히 보완함으로써 QoS 지원을 요구하는 플로우에대해서는 전통적인 이더넷이나 이더넷_IS 비해 훨씬 안정적인 서브넷 차원의 우선순위지원 서비스를 제공할 수 있음을 확인할 수 있었다.제공하는 멀티미디어 동기화 편집기와 변환기 및 상영기를 ScriptX를 이용하여 Windows95 상에 구현하였다.기 위한 간단한 例를 들어 봄으로써 이 글을 쓰는 동기으 일면을 대신하고자 한다.置함으로 이것을 Multi-Drop(points) system으로 swiching System을 利用 Mini-Network을 構成할 수도 있다.크 구성 관리 서버 시스템 개발에 대한 비용을 줄일 수 있다. 기대된다.e 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아이에서 그 주산기사망률(周産基死亡率)이 각각 가장 낮았다. 2. 사산(死産)과 초생아사망(初生兒死亡)을 구분(區分)하여 고려해 볼때 사산(死産)은 모성(母性)의 임신력(姙娠歷)

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.99-108
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• 2014

WBAN(Wireless Body Area Network) is network to support medical and non-medical services. It is susceptible to loss and delay of data. WBAN is required to satisfy many kinds of demands such as a variety of data rate and a data priority for providing various service. In this paper scheduling algorithm, considering a data priority and transmission delay time, is proposed to improve service quality of WBAN. The proposed algorithm operates by allocating a channel to a flow with longer transmission delay. When a packet, in a queue of herb, is left within a certain period, the packet is assigned a channel and transmitted according to a data priority. Through the comparison with other existing scheduling algorithms, it is confirmed that QoS is improved due to higher arrival probability of medical data and less delay time in the proposed algorithm.