• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.1045-1046
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• 2006

The IEEE 802.11e medium access control (MAC) is an emerging standard to support Quality of Service (QoS). A HCCA (HCF controlled channel access) scheduler of the standard IEEE 802.11e is only efficient for flows with strict constant bit rate (CBR) characteristics. In this paper, we propose a new HCCA scheduling scheme that aims to be efficient for both CBR and VBR flows. The proposed scheme uses fuzzy queue length predictions to tune its time allocation to stations. We present a set of simulations and provide performance comparisons with the reference HCCA scheduler.

• Journal of Information Technology Applications and Management
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• 제14권3호
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• pp.199-225
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• 2007

This study deals with the regulatory policy of government on the convergence of broadcasting and telecommunication by applying rent seeking theory to Internet Protocal TV (IPTV). Existing literature has mainly focused on the negative implications of rent seeking since Tullock [1967], Krueger [1974] and Buchanan [1980]. We have investigated the regulatory policy along with the progress of the convergence of broadcasting and telecommunication. Regulatory policy on broadcasting, despite its impartial intent. has created the entry barrier in the industry, resulting in high rents. Meanwhile, regulatory policy in telecommunication is more geared by the encouragement of more competitive environments, resulting in reasonably low rents in the market. Regulatory policy in the age of convergence needs to improve the efficacy of the industry and welfare, while maintaining the rent at a reasonably low level. This research has contributed to emphasizing the positive aspect of rent seeking in policy concerned with the convergence of broadcasting and telecommunication, notably IPTV.

• International Journal of Control, Automation, and Systems
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• 제5권3호
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• pp.317-323
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• 2007

Quality of Service (QoS) in the Internet depends on queuing and sophisticated scheduling in routers. In this paper, we address the issue of managing traffic flows with different priorities. In our reference model, incoming packets are first classified based on their priority, placed into different queues with different capacities, and then multiplexed onto one router link. The fuzzy nature of the information on Internet traffic makes this problem particularly suited to fuzzy methodologies. We propose a new solution that employs a fuzzy inference system to dynamically and efficiently schedule these priority queues. The fuzzy rules are derived to minimize the selected Lyapunov function. Simulation experiments show that the proposed fuzzy scheduling algorithm outperforms the popular Weighted Round Robin (WRR) queue scheduling mechanism.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.487-488
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• 2007

This Paper provides perceptual metrics for video quality based on properties of human visual system, and audio quality based on human audition. All metrics work without reference signals, allowing non-intrusive, in-service measurements. A simple and easy-to-learn user interface displays the metrics and saves them in popular file formats like CSV.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.327-327
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• 2000

In the 1990's several economically important marine fisheries collapsed or showed signs of extreme hardship owing to overcapitalization and excessive fishing pressure on the resources. Public concern was raised and demands voiced for more prudent fishery management practices. The United Nations responded and developed international guidelines, such as the FAO Code of Conduct for Responsible Fishing and the UN Straddling Fish Socks and Highly Migratory Fish Stocks Agreement These guidelines task fishery managers to take prudent steps to ensure the long-term viability of fisheries and fishery resources. Included in the guidelines are two particular demands that will challenge stock assessment scientists in the new millennium. They are application of the precautionary approach and the inclusion of ecological considerations in assessments and management advice. High-lighted in the presentation are examples from the central-western Pacifi skipjack tuna fishery and the eastern Pacific thresher shark fishery where insufficien information is affecting stock assessments. The shortcomings are further linked t the new challenges of applying the precautionary approach, such as reference points, and ecological considerations, such as predator-prey and oceanographic-regime shift.(omitted)

• 이베로아메리카
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• 제14권1호
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• pp.57-80
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• 2012

This year(2012) marks the 30th anniversary of the Malvinas (Falkland) war. A series of talks between the British and Argentina took place over 30 years until 1982, but failed to reach a conclusion on sovereignty. Argentina claims that sovereignty of the islands was transferred to Argentina from Spain upon independence, a principle known as uti possidetis juris. But UK claims that the principle of uti possidetis juris is not accepted as a general principal of international law, and UN General Assembly resolutions calling for negotiations are flawed because they make no reference to the islanders' right to choose their own future. In this situation, a huge amount of petroleum and natural gas has discovered near the Malvinas islands. To explore such situation, this article looks into history and present condition on dispute of Malvinas sovereignty, and also analyses de-colonialism and resource nationalism related to dispute of Malvinas sovereignty.

• Journal of Information Technology Applications and Management
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• 제29권5호
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• pp.1-12
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• 2022

This research is situated at the intersection between industry 4.0, circular economy and tourism, in an attempt to observe the fourth industrial revolution at the service of the application of circular economy principles in the tourism industry. This approach has gained importance due to the COVID-19 pandemic, which has accelerated fundamental dynamics of change linked to business digitization and environmental sustainability. Within the theoretical framework delimited by the aforementioned intersection, the 'goCircular Radar' project, launched by 'TheCircularLab', from Ecoembes (Spain), has been taken as an empirical reference. Among the 165 startups in the circular economy sector, special attention has been paid to those that are oriented, or have a potential application, to tourism. The activities they carry out are described, with particular attention to the technologies they use and their contribution to circularity.

• Journal of Positioning, Navigation, and Timing
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• 제3권4호
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• pp.131-141
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• 2014

Over the last decade, the Global Navigation Satellite System (GNSS) has been increasingly utilized as a meteorological research tool. The Korea Astronomy and Space Science Institute (KASI) has also been developing a near real-time GNSS precipitable water vapor (PWV) information management system that can produce a precise PWV for the Korean Peninsula region using GNSS data processing and meteorological measurements. The goal of this paper is to evaluate whether the precise point positioning (PPP) strategy will be used as the new data processing strategy of the GNSS-PWV information management system. For this purpose, quality assessment has been performed by means of a comparative analysis of the troposphere zenith total delay (ZTD) estimates from KASI PPP solutions (KPS), KASI network solutions (KNS), and International GNSS Service (IGS) final troposphere products (IFTP) for ten permanent GNSS stations in the Korean Peninsula. The assessment consists largely of two steps: First, the troposphere ZTD of the KNS are compared to those of the IFTP for only DAEJ and SUWN, in which the IFTP are used as the reference. Second, the KPS are compared to the KNS for all ten GNSS stations. In this step, the KNS are used as a new reference rather than the IFTP, because it was proved in the previous step that the KNS can be a suitable reference. As a result, it was found that the ZTD values from both the KPS and the KNS followed the same overall pattern, with an RMS of 5.36 mm. When the average RMS was converted into an error of GNSS-PWV by considering the typical ratio of zenith wet delay and PWV, the GNSS-PWV error met the requirement for PWV accuracy in this application. Therefore, the PPP strategy can be used as a new data processing strategy in the near real-time GNSS-PWV information management system.

• 인터넷정보학회논문지
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• 제17권4호
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• pp.145-159
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• 2016

본 연구는 최근 시장규모가 급격히 커지고 있는 주문형서비스(Video on Demand) 광고의 심의 규제를 위한 입법 공백의 문제점을 지적하고, 이를 위한 해결방안으로 통합방송법(안) 내 유사방송서비스 정의 및 규제를 위한 법적 근거를 마련하되 공동규제(Co-Regulation) 방식 채택을 제언하고 있다. 유료방송플랫폼 사업자들은 VoD 시청 규모 증가를 발판으로 VoD 광고를 수익모델로 삼아 제공 중에 있는데 실시간방송광고가 엄격한 심의 규제를 받는 반면, VoD 광고는 그렇지 못하다. 그 이유는 방송법을 비롯한 국내 법령에서는 VoD 및 VoD 광고 심의 규제를 위한 법적 근거가 부재하고, 광고 내용에 대한 규제는 사업자간 자율규제체계에 의존하고 있기 때문이다. 사업자 중심의 자율규제체계 하에서는 이용자(특히 어린이, 청소년과 같은 소수계층) 보호에 한계가 있고, 사업자가 광고주 영향력에 취약하며, 규제 실효성을 담보할 수 없다는 한계점을 가지고 있다. 이에 본 연구는 VoD 광고의 내용 규제 방향을 세 가지 측면에서 분석하였다. 첫째, 영국, 캐나다, 유럽연합(EU), 아일랜드와 같은 해외 주요국의 VoD 광고 규제 사례조사를 수행하였다. 각 국은 VoD 및 VoD 광고에 대한 법적 근거를 방송법 내지 그에 파생된 법령을 통해 확보하고 있었으며, 방송통신규제 기관 중심으로 심의규제를 하되 공동규제 방식을 채택하고 있었다. 둘째, VoD 광고 규제의 목적과 영역 측면에서 검토하였다. 본 연구가 제안하는 VoD 광고 규제의 목적은 이용자 보호이어야 하며, 그 영역은 내용심의로 제언하고 있다. 셋째, VoD 광고규제를 입법론 차원에서 검토하였다. 법적 근거는 일반법인 통합방송법(안)에 마련하되, 공동규제 방식 채택을 권고하였다. 개별법보다는 일반법을 권고한 이유는 VoD 서비스는 유사방송의 특성을 가지며 VoD를 제공하는 사업자가 유료방송사업자라는 지위 측면에서 통합방송법(안)에서 수용하는 것이 합리적이라는 점, 규제기관의 전문성 측면에서 실시간 방송광고를 심의하는 기관이 감독기능 및 지침제 개정 승인권을 보유하는 것이 일관성이 있다는 점에 근거한다. 본 연구가 제안한 VoD 광고에 대한 내용 심의 규제가 가능해진다면 광고 심의의 사각지대였던 VoD 광고 심의를 통해 이용자보호에 보다 충실할 수 있을 것이고, 자율규제체계가 가진 지속가능성 측면에서의 취약성을 어느 정도 극복할 수 있을 것으로 기대할 수 있다.

• 방송공학회논문지
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• 제14권5호
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• pp.573-588
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• 2009

본 논문에서는 네트워크 전송 중에 패킷손실에 의해 열화되는 IPTV 셋탑박스(STB: Set-Top Box) 재생영상의 화질을 모니터링하는 방법인 VR-VQMS(Visual Rhythm based Video Quality Monitoring Scheme)를 제안한다. 제안된 방법은 인코딩된 영상의 비쥬얼리듬(VR) 정보와 STB 재생영상의 비쥬얼리듬 정보를 특징정보로 사용하는 감소기준법 기반의 영상품질 측정 방법이며, 특히 영상품질관리 측면에서 패킷손실에 의한 화질열화를 정량화한 것이다. 화면열화 정도를 측정하기 위해 기존의 PSNR(peak-to-peak signal-to-noise ratio)을 수정한 NPSNR(Networked PSNR)이라는 새로운 품질척도를 정의하고 이를 기반으로 객관적 및 주관적 열화 척도를 정의하였으며, 온라인 VR-VQMS와 오프라인 VR-VQMS 두 가지의 화질열화 모니터링 방식을 제안하였다. 제안된 방법을 사용하면 화질열화가 발생된 시간과 지속시간, 발생횟수, 평균열화량 등에 대한 통계정보를 얻을 수 있을 뿐만 아니라 시청자의 주관적 체감화질까지 측정할 수 있으며, VR 정보를 사용하기 때문에 눈으로도 직접 이들을 확인할 수 있다는 장점이 있다. 모의실험 결과를 통하여 VR 정보로 추정한 NPSNR 을 이용하여 계산한 화질열화 척도값이 2D 재생영상에 대해 계산한 화질열화 척도값을 매우 근사적으로 추정하고, 시청자의 주관적 화질까지도 상당히 정확하게 추정함을 확인할 수 있었다. 제안된 방법은 IPTV 사업에서 개별 고객들의 시청품질을 평가하는 품질관리 솔루션의 일부로 적용가능하며, 복잡한 연산은 품질관리서버가 수행하고, STB는 작고 가벼운 에이전트 프로그램만 탑재하면 되기 때문에 실용성이 뛰어난 장점이 있다.