• 인터넷정보학회논문지
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• 제6권5호
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• pp.167-175
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• 2005

마이크로/피코셀 환경에서 이동체의 빈번한 위치 및 셀간 이동으로 인하여 많은 부가 트래픽이 발생한다. 이동체 위치 추정을 이용함으로서 효율적인 채널 할당과 QoS를 보장하는 핸드오프가 가능하다. 기존의 이동체 위치 추정 방안들은 단지 LOS 환경을 기반으로 하여 제시되었고 다중 경로 환경 또는 shadowing 환경에서는 성능의 감소를 가져왔다. 본 연구에서는 NLOS 환경, 그리고 수신 신호 세기 이외에 부정확한 다수의 위치 결정 파라미터를 고려함으로서 추정의 정확성을 증가시키는 다기준 의사 결정 방안을 제시한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권7호
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• pp.2530-2547
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• 2015

In the recent years, femtocell technology has received a considerable attention due to the ability to provide an efficient indoor wireless coverage as well as enhanced capacity. However, under the spectrum sharing between femtocell user equipment (FUEs) and the owner of spectrum macrocell user equipment (MUEs), both may experience higher uplink interference to each other. This paper proposes a novel distributed power control algorithm for the interference management in two-tier femtocell networks. Due to the assignment of licensed radio frequency to the outdoor macrocell users, the access priority of MUEs should be higher than FUEs. In addition, the quality of service (QoS) of MUEs that is expressed in the target signal-to-interference-plus-noise ratio (SINR) must always be achieved. On the other hand, we consider an efficient QoS provisioning cost function for the low-tier FUEs. The proposed algorithm requires only local information and converges even in cases where the frontiers of available power serve the target SINRs impossible. The advantage of the algorithm is the ability to implement in a distributed manner. Simulation results show that the proposed algorithm based on our cost function provides effective resource allocation and substantial power saving as compared to the traditional algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.2016-2034
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• 2011

Ubiquitous Healthcare (u-Healthcare) is the intelligent delivery of healthcare services to users anytime and anywhere. To provide robust healthcare services, recognition of patient daily life activities is required. Context information in combination with user real-time daily life activities can help in the provision of more personalized services, service suggestions, and changes in system behavior based on user profile for better healthcare services. In this paper, we focus on the intelligent manipulation of activities using the Context-aware Activity Manipulation Engine (CAME) core of the Human Activity Recognition Engine (HARE). The activities are recognized using video-based, wearable sensor-based, and location-based activity recognition engines. An ontology-based activity fusion with subject profile information for personalized system response is achieved. CAME receives real-time low level activities and infers higher level activities, situation analysis, personalized service suggestions, and makes appropriate decisions. A two-phase filtering technique is applied for intelligent processing of information (represented in ontology) and making appropriate decisions based on rules (incorporating expert knowledge). The experimental results for intelligent processing of activity information showed relatively better accuracy. Moreover, CAME is extended with activity filters and T-Box inference that resulted in better accuracy and response time in comparison to initial results of CAME.

• Journal of Information Processing Systems
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• 제5권2호
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• pp.97-104
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• 2009

In this paper we propose a Differentiated Services Based Admission Control and Routing Algorithm for IPv6 (ACMRA). The basic DiffServ architecture lacks an admission control mechanism, the injection of more QoS sensitive traffic into the network can cause congestion at the core of the network. Our Differentiated Services Based Admission Control and Routing Algorithm for IPv6 combines the admission control phase with the route finding phase, and our routing protocol has been designed in a way to work alongside DiffServ based networks. The Differentiated Services Based Admission Control and Routing Algorithm for IPv6 constructs label switched paths in order to provide rigorous QoS provisioning. We have conducted extensive simulations to validate the effectiveness and efficiency of our proposed admission control and routing algorithm. Simulation Results show that the Differentiated Services Based Admission Control and Routing Algorithm for IPv6 provides an excellent packet delivery ratio, reduces the control packets' overhead, and makes use of the resources present on multiple paths to the destination network, while almost each admitted flow shows compliance with its Service Level Agreement.

• 전자공학회논문지B
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• 제32B권1호
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• pp.161-170
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• 1995

본 논문에서는 전문가 시스템의 사용자 인터페이스 모듈을 구현하기 위하여 사용자 인터페이스의 구조적 스키마(description schema)로서 수트(SUIT : Schematic User Interface Tasks)를 정의하였으며, 이를 관리하는 '수트관리기'(SUIMAN : SUIT Manager)를 구현하였다. 수트는 전문가 시스템의 사용자 인터페이스 설계 초기 단계에서, 수트를 사용하여 사용자 인터페이스 구현을 위해 이루어져야 할 행위를 개념적인 상위 수준에서 기술한다. 수트관리기는 수트에서 기술된 것이 언제 실행될지 결정한다. 그래픽 사용자 인터페이스의 실현은 X-윈도우의 MOTIF 라이브러리에 의해 제공되는 함수들을 실행함으로써 이루어진다. 즉, 수트관리기는 수트에 기술된 사용자 인터페이스 명세를 해석하여 실제 그래픽 사용자 인터페이스를 자동으로 실현시킨다. 수트와 수트관리기를 사용함으로써 전문가 시스템 개발에서 사용자 인터페이스 모듈의 보다 신속한 개발이 가능하다. 본 논문의 사용자 인터페이스 기술 방법은 `자동 회전 구성 전문가 시스템`의 사용자 인터페이스에 사용되었다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.68-71
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• 2009

All-IP network requires change of the existing IP network engineering methods as the convergence service market between communication and broadcasting industries using IP network is growing rapidly. Especially the video services like IPTV require more strict transmission quality and higher bandwidth than the existing data services. So it is difficult to design All-IP network by the over-provisioning method which used to be used for the existing IP network design. It also requires a heavy investment which becomes one of big obstacles to the IPTV service expansion. In order to reduce the investment costs, it is required to design an optimized network by maximizing the utilization of the network resources and at the same time maintaining the customer satisfaction in terms of service quality. In this paper, we first analyze the effects of IPTV traffic on the existing internet. Then we compare two traffic engineering technologies, which are dimensioning without admission control and dimensioning with admission control, on the All-IP network design by simulation. Finally, we suggest cost effectiveness of traffic engineering technologies for designing the All-IP network.

• 정보처리학회논문지C
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• 제11C권6호
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• pp.807-814
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• 2004

본 논문은 차등화 서비스를 지원하는 MPLS망 환경에서 효율적으로 QoS 차등화 서비스를 지원하기 위해 네트워크의 트래픽 정보를 갱신하여 대역폭을 재 할당해 주는 방법에 대하여 연구하고 평가하였다. MPLS 망에서의 차등화 서비스는 RSVP(Resource Reservation Protocol)의 자원 예약 매커니즘에 의해 제공되고 있지만 이 방법 또한 정적인 자원 선점 방법에 기초하고 있다. 네트워크 망에서의 대역폭 할당을 정적인 자원 선점 차원에서만 접근 한다면, 어느 특정 서비스 클래스에 대역폭 할당 요청이 집중되고, 그렇지 않은 서비스 클래스가 존재 할 경우 유휴 대역폭을 발생시킬 수 있는 문제가 있다. 본 논문에서는 현재 네트워크 트래픽 상태에 기초하여 동적으로 대역폭을 재 할당해서 대역폭 사용을 최대화 시켰다.

• Journal of Communications and Networks
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• 제3권4호
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• pp.317-323
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• 2001

Traditional configuration management involves complex labor-intensive processes performed by experts. The configuration tasks such as installing or reconfiguring a system, provisioning network services and allocating resources typically involve a large number of activities involving multiple network elements. The network elements may be associated with proprietary configuration management instrumentation and may also be spread across heterogeneous network domains thereby increasing the complexity of configuration management. This paper introduces an architecture for the self-configuration of networks (SELFCON). The proposed architecture involves a directory server, which is uses to maintain configuration information. The configuration information stared in the directory server is modeled using the standard DEN specification thereby allowing effective exchange of network, system and configuration management data among heterogeneous management domains. SELFCON associates configuration intelligence with the components of the network, rather than limit it to a centralized management station. The network elements are notified about related changes in configuration policies, based upon which, they perform self-configuration. SELFCON is able to provide automation of configuration management and also an effective unifying framework for enterprise management.

• Journal of Communications and Networks
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• 제3권4호
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• pp.297-306
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• 2001

In the last couple of years service management has gained more and more momentum in the research community. Nowadays, as complexity of IT-services is increasing, these services are usually composed of interdependent, layered services hosted by various providers. Therefore, a strong cooperation of providers involved in service provisioning is needed, especially regarding their management processes and systems. One important step is to establish a common understanding about service-related terms in order to be able to specify service functionality and the resulting management tasks. Additionally, means to analyze and identify the necessary actors and the corresponding inter- and intra-organizational relationships are needed. This paper presents an extended version of the MNM service model which provides a generic model defining commonly needed service-related terms, concepts and structuring rules in a general and unambiguous way. Furthermore, we demonstrate the application of the MNM service model by modeling a riser help desk service based on a concrete scenario. The experience gained from modeling is used to discuss the benefits of service modeling in general.

• 융합보안논문지
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• 제16권7호
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• pp.159-165
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• 2016

NFV (Network Function Virtualization)를 통해 네트워크 사업자, 캐리어 등과 같은 업계에서는 NFV가 추구하는 S/W 기반의 장치를 통하여 신규 서비스 제공의 신속성과 네트워크 구축의 유연성 (flexibility)를 향상 시켜 CAPEX/OPEX를 대폭 감소시키고자 하였다. NFV 네트워크를 구축하여 동적인 서비스를 제공하기 위한 가장 중요한 고려사항 중의 하나는 네트워크 서비스의 기본 구성 요소인 리소스 (VNF)들을 적재적소에 동적으로 할당하는 방식을 결정하는 것이다. 본 논문에서는 NFV에서 임의의 NS를 제공하기 위해 필요한 VNF의 노드, 링크 할당 및 노드에서의 스케줄링에 관한 최신 연구 동향을 분석하였다. 또한 본 논문에서는 이러한 연구결과를 기반으로 향후 RA (Resource Allocation)에서 추가적으로 연구해야 하는 스케줄링 문제 또한 제안하였다.