• 디지털콘텐츠학회 논문지
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• 제13권4호
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• pp.625-629
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• 2012

NGN 운용과정의 품질 보증을 위해 어떤 체계하에서 품질이 테스트 되어야 하는지 방법론을 도출하기 위해서 멀티미디어 트래픽을 중심으로 NGN 품질측정 프레임워크를 제시한다. 테스트베드는 NGN 운용과정에서 QoS 측정 메트릭스, 측정구간과 측정계위, 측정도구, 측정장비, 측정방법 및 측정결과 분석에 대한 일련의 프로세스와 방법론을 모델화한다. 이 모델은 향후 NGN 품질보증 활동에 활용토록 한다. 통신서비스 품질은 스스로 보장되지 않으며 끊임없이 측정되고 관리될 때에 만 품질 목표수준 확보가 가능하다. NGN 네트워크기술 패러다임 중요성을 감한할 때 NGN 운용상의 품질관리에 대한 연구는 앞으로 활발하게 추진되어야 할 핵심 소재이다.

• 한국환경과학회지
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• 제20권1호
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• pp.81-91
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• 2011

Air quality monitoring networks are very important facilities to manage urban air pollution control and to set up an environmental policy. Since air quality monitoring network of Daegu was allocated from 1980s to mid-90s, there is need to reevaluate it and relocated its site. This study was evaluated the position of Daegu air quality monitoring station by unit environmental sensitivity index, grid emission rate, CAI (Comprehensive Air-quality Index) point. The investigation domain covered an area of 16 $\times$ 24 km centered at the metropolitan area of Daegu with grid spacing of 2 km. The location of alternative air quality monitoring networks was selected through optimization and quintiles analysis of total score. The result showed that all things considered, new air quality monitoring network need to install grid numbers 10, 28, 36, 37, 46. We also recommand three scenarios of alternative air quality monitoring network when considering unit environmental sensitivity index, emission rate and CAI point.

• Journal of information and communication convergence engineering
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• 제13권1호
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• pp.7-14
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• 2015

In a multi-hop wireless network, connectivity is determined by the link that is established by the receiving signal strength computed by subtracting the path loss from the transmission power. Two path loss models are commonly used in research, namely two-ray ground and shadow fading, which determine the receiving signal strength and affect the link quality. Link quality is one of the key factors that affect network performance. In general, network performance improves with better link quality in a wireless network. In this study, we measure the network connectivity and performance in a shadow fading path loss model, and our observation shows that both are severely degraded in this path loss model. To improve network performance, we propose power control schemes utilizing link quality to identify the set of nodes required to adjust the transmission power in order to improve the network throughput in both homogeneous and heterogeneous multi-hop wireless networks. Numerical studies to evaluate the proposed schemes are presented and compared.

• 한국정보시스템학회지:정보시스템연구
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• 제24권1호
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• pp.67-94
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• 2015

Recently, the popularity of Social Network Service (SNS) along with the spread of smart phone, personal computer and tablet PC helps personal network to construct new forms of services in cyberspace. As such, SNS plays a significant role in constructing diverse online networks and there is a growing interest on SNS at societal level. In this vein, the purpose of the research was to find the factors affecting the continuance intention to use social network services. The major findings are summarized as follows. First, "System Quality", "Contents Quality", "Personal Innovativeness", "Self-Efficiency", "Honor Benefit" has significant effects on "Relationship Quality". Yet, "Economic Benefit" is not statistically significant on "Relationship Quality". Second, "Relationship Quality" has a significant effect on "Continuous Usage Intention". Last, our research discovered the relationship between exogenous variables which would serve as valuable inputs in the development of strategic guideline and plan for SNS companies and related services.

• 한국정보시스템학회지:정보시스템연구
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• 제21권4호
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• pp.133-153
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• 2012

This study explores the factors influencing user satisfaction of mobile IPTV and their relationship. We formulate the research model based on characteristics of mobile device and IPTV. Responsiveness, contents satisfaction, price satisfaction, aesthetic simplicity, network quality are proposed as essential antecedents of mobile IPTV satisfaction. We also suggest network quality and gender as moderators. Our data analysis with 297 mobile IPTV users shows contents and price have significant positive effect on mobile IPTV satisfaction. Network quality shows positive moderation effect on the relationship between responsiveness and satisfaction.

• 대한가정학회지
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• 제45권5호
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• pp.75-83
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• 2007

The purpose of this study was to investigate the relationships between peer victimization by peers, bullying, and friendships, with a focus on friendship network, friendship quality, and friends' characteristics. The subjects were 678 fifth and sixth grade primary school children recruited from a public school in Bucheon city. The peer nomination index was used to assess peer victimization, bullying, and friendship network. In addition, children themselves reported on the quality of their friendships using the Friendship Quality Scale. The results showed that victimization by peers was influenced by friendship network size, support, and victimization of friends, whereas bullying was explained by support and the bullying behaviors of friends.

• 한국정밀공학회지
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• 제14권1호
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• pp.101-107
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• 1997

Recently, as the raw water quality becomes to be polluted and the seasonal and local variation of water quality becomes to be severe, an exact control of coagulant dosing have been required in the water treat- ment plant. The amounts of coagulant is related to the raw water quality such as turbidity, alkalinity, water temperature, pH and edectrical conductivity. However the process of chemical reaction has not been clarified so far, so the dosing rate has been decided by jar-test, which is taken one or two hours. For the sake of this coagulant dosing control, fuzzy neural network to fuse fuzzy logic and neural network was proposed, and the scheme was applied to automatic determination of coagulant dosing rate. This controller can automatically identify the if-then rules and tune the membership functions by utilizing expert's cintrol data. It is shown that determination of coagulant dosing rate according to real time sensing of water quality is very effect.

• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.340-345
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• 2015

The Internet traffic is forecasted to grow at a compound annual rate of 21 % from 2013 to 2018, according to surveys carried out by Cisco [1]. Network resources are significantly over-provisioned in today's networks, and it is quite common to see link utilization in the 30-40% range [2]. Additionally, the multi-media services have widely divergent bandwidth and Quality of Experience (QoE) requirements. Unfortunately, the huge transmission capacity will increase the power consumption of network equipment [3]. Applications Coordinated with Transport, Internet Protocol and Optical Networks (ACTION) [4] has been proposed to realize a multi-QoE, application-centric, and highly energy-efficient network that leverages flexible elastic optical network technologies [5-7]. This paper provides key network technologies for realizing the ACTION, which are a virtual optical slice core network and a Time Division Multiplexing (TDM)-based deterministic active optical access network.

• 한국정보통신학회논문지
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• 제10권12호
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• pp.2166-2172
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• 2006

인터넷의 활성화와 인트라넷 구축을 통한 그룹웨어의 확산과 함께 LAM의 초고속화 기술이 급진적으로 발전되어 왔으며, 이러한 발전은 고품질의 실시간 서비스에 대한 사용자의 요구에 의해 새로운 형태의 통합네트워크 형태로 발전되어 가고 있다. 통합네트워크는 데이터, 음성 및 영상 응용 서비스가 함께 제공될 수 있는 통신망으로서 궁극적으로는 통합된 단일 네트워크 플랫폼으로 발전해 갈 것으로 보인다. 본 논문에서는 IP기반의 통합서비스를 제공하기 위하여 실질적인 GoS 제공 기술, 프로그래머블 스위치 네트워크 구조 기술과 통합 호 제어 처리 기술을 포함하는 차세대 통합 LAN에 관한 연구결과를 제시하고자 한다.

• 환경영향평가
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• 제30권2호
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• pp.75-88
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• 2021

본 연구에서는 금강 수계의 자동측정망 중 6개 지점을 선정하고, 이와 동일하거나 인근에 위치해 있는 수질측정망 지점을 대상으로 두 지점의 수질특성 파악하고 통계 분석을 통하여 상관성을 평가하였다. 또한, 수질 분석결과를 활용하여 수질 지수로 변환하고 등급으로 표현해 비교하였다. 연구에 필요한 자료는 최근 4년간(2016-2019)의 국가물환경측정망 데이터를 활용하였으며 수온, pH, EC, DO, TOC, TN, TP를 평가항목으로 선정하였다. 수질 분석 결과, 자동측정망과 수질측정망의 수질농도는 일부 측정값의 차이는 보였지만 대부분 지점에서 일정한 비로 변동하는 경향을 보였다. 항목 간 상관분석결과 수온, EC, DO 항목은 측정망간 상관성이 매우 높았고, TOC, TN, TP 항목은 기본항목에 비해 낮은 상관성을 보였으나 일부 측정망을 제외하고 0.7 이상(상관계수 r)의 높은 상관관계를 나타냈다. 수질 지수 분석결과 자동측정망 수질지수와 수질측정망 수질지수가 비슷한 경향을 보이는 것으로 평가되었으며, 두 결과 모두 하류로 갈수록 지수점수는 낮아져 오염도가 증가되고 있음을 쉽게 파악할 수 있었다.