• 한국인터넷방송통신학회논문지
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• 제8권6호
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• pp.77-88
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• 2008

본 논문은 G-PON 기술 기반 FITB/H 시스템 구현에 관한 것이다. 이 시스템은 TDM 및 데이터 경로가 10msec내에 절체할 수 있는 이중화 기능을 지원한다. 이 시스템은 OLT와 ONU/ONT로 구성되었다. OLT는 시스템 당 최대 32개의 2.5Gbps 라인 인터페이스를 지원하며, 향후 디지털 통신 방송 융합 서비스를 고려한 설계로 융통성과 확장성을 가지고 있다. OLT 시스템은 스위치 모듈, 가입자 모듈, 프로세서 모듈, 그리고 G-PON 링크 모듈로 이루어져 있으며, 리녹스 운영체제를 탑재하고 있다. ONT는 가입자 댁내에 실장되어 TPS 서비스를 제공할 수 있다. 또한 ONU는 IP-TV 신호 전달 특성을 개선하기 위하여 IP-TV 전용 인터페이스를 가지고 있다.

• 한국IT서비스학회지
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• 제12권1호
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• pp.323-340
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• 2013

As the importance of collaboration becomes critical in today's open and complex business environment network, the issues and solutions on compatibility and reusability between different kinds of applications are being increasingly important as well in systems analysis and design. And therefore, service-centered SOA is receiving attention in such business environment as a strategic approach that makes possible for prompt action according to the needs of users and business process. Various implementation methodologies have been proposed for SOA, however, in practical aspects most of them have some problems since they fail to propose specific policies in definition and identification of services for the exact user requirements and business situations. To solve or alleviate those problems, this paper suggests a new service identification model based on hierarchical ontology, where three different ontologies such as business ontology, context ontology and service ontology are proposed to define the relationship and design the link between user requirements, business process, applications and services. Through a suggested methodology in this paper, it would be possible to provide proactive services that meets a variety of business environments and demands of user. Also, since the information can be modified adaptively and dynamically by hierarchical ontology, this study is expected to play a positive role in increasing the flexibility of systems and business environments.

• 무역상무연구
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• 제24권
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• pp.51-72
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• 2004

Over the past fifty years, the share of the World's shipping fleet operating under open registry has grown from 4 % to almost half of the total tonnage. While there has been strong opposition based on the costs of maritime disasters and opposition both from the traditional maritime nations, which have suffered erosion of their fleets, and from labour unions, which point to worker exploitation, the shipping companies have found the greater operational and financial flexibility which accompanies open registry to be a considerable attraction The paper consists of seven sections. Section 1 explains the background and of the study. Section 2 reviews the characteristics and definition of FOC. Section 3 is to identify ship register categories and their competitive conditions. Section 4 tackles the emerging forces of globalisation-the advent of FOC. Section 5 deals with legal maritime framework. Section 6 tackles the current structure and characteristics of FOC vessels. Some concluding comments follow in the last section.

• Journal of Communications and Networks
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• 제2권1호
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• pp.35-45
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• 2000

this paper presents the concept of "mobile ATM', a proposal for third-generation (3G) mobile communication network infrastructure capable of supporting flexible evolution of radio technologies from today's cellular and data services towards future wireless multimedia services. Mobile ATM provides generic mobility management and QoS-based transport capabilities suitable for integration of multiple radio access technologies including cellular voice. wireless data, and future broadband wireless services. The architecture of a mobile ATM network is outlined in terms of the newly-defined "W-UNI" interface at the radio link and "M-UNI"and "M-UNI" interface which supports unified access for WATM and non-ATM mobile terminals through corresponding interworking functions (IWF) is explained. leading to an understanding of how different radio access technologies are supported by the same ATM-based core network infrastructure. Generic mechanisms for handoff and location management within the core mobile network are discussed. and related protocol extensions over the "W-UNI" and "M-UNI/NNI"interfaces are proposed. the issue of "crossover switch (COS)" selection in mobile ATM is considered, and a unified handoff signaling syntax which supports flexibility in COS selection is described. Typical signaling sequences for call connection and handoff using the proposed protocols are outlined. Experimental results form a proof-of-concept mobile ATM network prototype are presented in conclusion.

• 자원ㆍ환경경제연구
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• 제21권2호
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• pp.301-319
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• 2012

2012년부터 RPS 제도가 시행됨에 따라 신재생에너지 분야에서의 투자가 활발히 이루어질 것으로 예상된다. 신재생에너지를 통한 기업의 온실가스 감축투자는 장기적으로 기술진보와 국내 전력가격에도 영향을 미치는 중요한 요소이다. 한편, 국내에 온실가스 감축정책 수단으로 배출권거래제가 논의 중인 바, 유사한 성격의 두 제도가 기업의 환경투자 의사결정에 미치는 영향을 분석하도록 한다. 투자의 비가역성과 배출권 및 REC 가격의 불확실성을 고려하는 실물옵션 모형을 이용하여, 게이트웨이의 설정을 통한 배출권과 REC의 호환성이 보장될 때에 투자 인센티브를 분석하였다. 환경투자를 통해 온실가스 감축이 충분히 클 경우에는 투자에 대한 게이트웨이의 긍정적인 효과가 확인되는 것으로 나타났다. 신재생에너지 투자효과에 대한 보다 엄밀한 분석을 위하여 향후 발전사 데이터의 구축을 통해 실증분석이 추가로 이루어져야 할 것이다.

• The Journal of Asian Finance, Economics and Business
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• 제7권5호
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• pp.237-248
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• 2020

The purpose of this study is to investigate and reconfirm the research instruments and variables that have been developed by prior study and built new concepts from empirical research results. Besides analyzing the essential role of fundamental, rational, and psychology aspects to increase employee's intention to stay in a company, which is useful for the development of human resource development strategies for millennial workers in the future. A total of 438 non-student male respondents aged 23-36 years, with unmarried status and not working in the SOE sector or as a civil servant, were surveyed with questionnaires. The study was conducted in Makassar, Indonesia. Data collection uses a survey with the second-order model approach and regression with control variables. The findings of this study suggest the existence of an inter-relationship between fundamental, rational and psychological aspects. They are inseparable and have a positive and significant influence. Broadly speaking, the link between fundamental, psychology and rational aspects states that the decision for millennial male workers to stay in the company will depend on whether the company has a good image and reputation, the level of attention the organization pays to career development, is competent, and applies regulations and rules with flexibility.

• 방송과미디어
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• 제11권1호
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• pp.68-77
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• 2006

The Cognitive Radio (CR) technology is a promising solution for exploiting the limited spectrum resources and providing flexibility of spectrum usage. Future interactive broadcasting service can be realized by utilizing CR concept, since the up-link return channel can be found by the spectrum sensing method, which is core functional block of the CR system. In this paper, the spectrum sensing technologies of CR system is presented. First the system architecture of the CR with spectrum sensing block is presented. The suggested spectrum sensing technique consists of the coarse and the fine spectrum sensing. The coarse spectrum sensing technique adopted the wavelet transform to provide the multi-resolution sensing feature - Multi-Resolution Spectrum Sensing (MRSS). The fine spectrum sensing technique uses the beneficial properties of the autocorrelation function Analog Auto-Correlation (AAC). The simulation results for the proposed sensing technologies are presented for various incumbent signals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2231-2252
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• 2012

With the prevalence of diverse services-oriented applications, such as IPTV systems and on-line games, the current underlying communication networks face more and more challenges on the aspects of flexibility and adaptability. Therefore, an effective and efficient multicast routing mechanism, which can fulfill different requirements of different personalized services, is critical and significant. In this paper, we first define the neighbor gradient, which is calculated based on the weighted sum of attributes such as residual link capacity, normalized hop count, etc. Then two distributed multicast routing algorithms which are neighbor Gradient-based Multicast Routing for Static multicast membership (GMR-S) and neighbor Gradient-based Multicast Routing for Dynamic multicast membership (GMR-D), are proposed. GMR-S is suitable for static membership situation, while GMR-D can be used for the dynamic membership network environment. Experimental results demonstrate the effectiveness and efficiency of our proposed methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.349-352
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• 2001

FACTS technology is developed into the sophisticated system technology which combines conventional power system technology with power electronics, micro-process control, and information technology. Its objectives are achieving enhancement of the power system flexibility and maximum utilization of the power transfer capability through improvements of the system reliability, controllability, and efficiency [1]. As a series and shunt compensator, UPFC consists of two inverters with common dc link capacitor bank. It controls the magnitude of shunt bus voltage and real and reactive power flow of transmission line[2]. In this paper, we present the design, implementation and test results of developed 20kVA level prototype UPFC. It is applied to power system simulator and controls the real and reactive power flow and shunt bus voltage magnitude.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.374-376
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• 2001

FACTS technology is developed into the sophisticated system technology which combines conventional power system technology with power electronics, micro-process control, and information technology. Its objectives are achieving enhancement of the power system flexibility and maximum utilization of the power transfer capability through improvements of the system reliability, controllability, and efficiency[1]. As a series and shunt compensator, UPFC consists of two inverters with common dc link capacitor bank. It controls the magnitude of shunt bus voltage and real and reactive power flow of transmission line[2]. In this paper, we present the design and control algorithm of UPFC simulator for KERI simulator. As a control algorithm is implemented by digital controller, we consider sample-and-hold of signals In this simulation, we use EMTDC/PSCAD V3.0 software which can simulate instantaneous voltage and current.