• 전자통신동향분석
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• 제24권1호
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• pp.50-58
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• 2009

FTTH 망에 널리 적용되고 있는 PON 기술은 OPEX 비용을 최소화 하면서 가입자에게 많은 대역을 제공할 수 있는 매력적인 기술이다. 이러한 대표적인 PON 기술에는 가입자간 시분할 방법에 의하여 데이터를 전송하는 TDMA-PON이 있으며, 여기에는 IEEE802.3의 EPON과 ITU-T/FSAN의 GPON이 포함된다. 향후 IPTV 등을 포함한 신규 서비스 등장과 광대역을 요구하는 미래 가입자 서비스를 충족시키기 위해서 PON 기술은 지속적으로 발전할 것으로 예상된다. 본 고에서는 IEEE802.3과 ITU-T/FSAN에서 추진중인 차세대 광가입자망 표준화 활동 동향을 소개한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.187-188
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• 2006

In CDMA based mobile communication network, signaling messages are routed through Signaling Transfer Point(STP) which is responsible for MTP layer 3 switching. As WCDMA based UMTS network is considered as next generation technology allowing global roaming services, all nodes in networks have their own identity number called Global Title(GT). Therefore, it is essential to introduce Signaling Gateway(SG) responsible for SCCP layer switching to solve the problem each node has all GT tables including even all overseas nodes. In this paper, we propose the signaling network architecture in UMTS networks using SG and we show that we can reduce CAPEX and OPEX in each node. To show the validity of the proposed method some simulations are given in which the results can be expected by intuitive observation.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.73-73
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• 2020

GWI(2019)에 따르면, 2020년 기준 세계 물시장은 약 996조 원(8,034억 $) 규모로 추정되며, 2024년까지 연평균 3.4%대의 성장을 기록할 것으로 전망된다. 이에 선진 국가를 비롯 글로벌 기업들은 물시장의 선점을 위하여 경주한지 오래이며, 우리 정부는 2000년을 기점으로 물산업 육성관점에서 해외시장 진출을 강조하고 있다. 하지만 국내 기업의 해외시장 진출을 위해서는 무엇보다 중점 육성 분야 및 타겟시장 등의 선정이 필요한데, 이를 위한 분석적 정보는 찾아보기 어렵다. 이에 본 연구는 데이터 기반의 물시장 현황 및 전망을 분석·제공함으로써, 물기업의 중점 육성분야 및 타겟시장 선정에 도움을 제공하고자 하였다. 분석 결과는 ① 사업별 물시장 ② 제품별 물시장, ③ 지역별 물시장으로 구분하였으며, 시장 유형은 자본투자와 운영시장으로 구분하였다.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.276-290
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• 2020

연구목적: 국내 항만시설의 건설역사는 100년 이상 되었으며 최근 까지 현대적 시설이 지속적으로 건설되어 확장되고 있다. 그러나, 해양환경의 변화 및 물동량의 증가 등으로 초기 건설당시의 요구 성능조건을 유지하기는 쉽지 않다. 특히, 사용년수가 오래된 항만구조물의 경우, 선박의 대형화와 사용빈도 증가, 자연재해의 규모 증가등으로 안전성능과 기능관리가 매우 중요해져 가고 있다. 연구방법: 이에 본 연구는 항만시설의 구조형식별 상태변화를 조사하고 이를 기반으로 성능개선 및 수명연장활동에 기여하는 보수보강활동과 그 이력을 분석하였다. 연구결과: 항만시설 유지관리전략수립에 활용 가능한 성능개선비용(CAPEX)과 수선유지활동(OPEX)을 구별하고 이를 통한 유지관리전략수립에 활용 가능한 비용모델을 제시하였다. 결론: 이러한연구는 향후 시설물 중장기 투자의사결정에 큰 기여를 할 것으로 기대된다.

• 전기학회논문지
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• 제62권11호
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• pp.1520-1527
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• 2013

The purpose of this study is to derive COE reduction targets of offshore wind power in Korea. In addition, innovation factors for achieving the COE reduction targets were derived. Also the COE reduction targets of offshore wind power was to improve that national policy, technology, industry and improving regulations would like to help. The results of this study has been created based on the various assumptions, scenarios and experts' discussions. Currently, offshore wind power generation price is 229.72won/kWh in 2012. According to the study, COE of offshore wind power has been proposed 88.8won/kWh at third scenario by 2030. This result has shown competitiveness with fossil fuel power generation.

• ETRI Journal
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• 제40권3호
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• pp.355-365
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• 2018

The increase in data traffic calls for investment in mobile networks; however, the saturating revenue of mobile broadband and increasing capital expenditure are discouraging mobile operators from investing in next-generation mobile networks. Mobile network sharing is a viable solution for operators and regulators to resolve this dilemma. This research uses a difference-in-differences analysis of 33 operators (including 11 control operators) to empirically evaluate the cost reduction effect of mobile network sharing. The results indicate a reduction in overall operating expenditure and short-term capital expenditure by national roaming. This finding implies that future technology and standards development should focus on flexible network operation and maintenance, energy efficiency, and maximizing economies of scale in radio access networks. Furthermore, mobile network sharing will become more viable and relevant in a 5G network deployment as spectrum bands are likely to increase the total cost of ownership of mobile networks and technical enablers will facilitate network sharing.

• 한국통신학회논문지
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• 제42권2호
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• pp.358-365
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• 2017

개도국에서 비용 효율적인 LTE (Long Term Evolution)망을 구축하기 위해서는 선진국 위주의 설계 및 구축방식과는 차별화된 LTE 기술 분석과 적용이 필요하다. 본 연구에서는 이동 통신 네트워크 구성에서 대부분의 CAPEX (Capital Expenditure) 및 OPEX (Operating Expenditure)를 차지하는 RAN (Radio Access Network) 구성에 대해 개도국에 적합할 수 있는 설계 방안을 제안하고 사례를 통해 결과 검증을 하였다. 본 연구결과는 향후 개도국들이 도심지역 또는 외곽지역에 LTE 망을 위한 RAN을 비용 효율적 관점에서 설계 및 구축할 때 참고가 될 것으로 판단된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4618-4639
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• 2018

One of the most innovative paradigms for the next-generation of wireless cellular networks is the cloud-radio access networks (C-RANs). In C-RANs, base station functions are distributed between the remote radio heads (RHHs) and base band unit (BBU) pool, and a communication link is defined between them which is referred as the fronthaul. This leveraging link is expected to reduce the CAPEX (capital expenditure) and OPEX (operating expense) of envisioned cellular architectures as well as improves the spectral and energy efficiencies, provides the high scalability, and efficient mobility management capabilities. The fronthaul link carries the baseband signals between the RRHs and BBU pool using the digital radio over fiber (RoF) based common public radio interface (CPRI). CPRI based optical links imposed stringent synchronization, latency and throughput requirements on the fronthaul. As a result, fronthaul becomes a hinder in commercial deployments of C-RANs and is seen as one of a major bottleneck for backbone networks. The optimization of fronthaul is still a challenging issue and requires further exploration at industrial and academic levels. This paper comprehensively summarized the current challenges and requirements of fronthaul networks, and discusses the recently proposed system architectures, virtualization techniques, key transport technologies and compression schemes to carry the time-sensitive traffic in fronthaul networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권6호
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• pp.1979-1995
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• 2015

Network convergence is regarded as the development tendency of the future wireless networks, for which self-organization paradigms provide a promising solution to alleviate the upgrading capital expenditures (CAPEX) and operating expenditures (OPEX). Self-optimization, as a critical functionality of self-organization, employs a decentralized paradigm to dynamically adapt the varying environmental circumstances while without relying on centralized control or human intervention. In this paper, we present comprehensive surveys of heterogeneous networks (HetNets) and investigate the enhanced self-optimization models. Self-optimization approaches such as dynamic mobile access network selection, spectrum resource allocation and power control for HetNets, etc., are surveyed and compared, with possible methodologies to achieve self-optimization summarized. We hope this survey paper can provide the insight and the roadmap for future research efforts in the self-optimization of convergence networks.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.204-212
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• 2022

Recently, the Korean government has been actively promoting the smart city as their strategic agenda. However, to build smart cities that are greener, the authors believe it is essential to rapidly transit conventional energy sources such as fossil fuels to renewable energy. Although there is a big potential for Offshore wind in Korea, there has not been a full-scale commercial offshore wind farm until today. Since Korea is relatively a new market compared to the EU, it can be risky for developers. The authors will introduce risk management best practices in the offshore wind industry applicable to the Korean environment. This paper will mainly introduce an offshore wind project size of 99 MW. The project is expecting a Finance Close (FC) in Q3 2022, so the project team has prepared a risk register with over 150 risks and levers throughout the project lifecycle. Overall risks include risks with Development Expenditure (DEVEX) impact, a Capital Expenditure (CAPEX) impact, and an Operating Expenditure (OPEX) impact. Based on the identified risks, a more qualitative assessment of Cost and Schedule Impact was conducted. In conclusion, a Monte Carlo simulation was performed to propose a quantitative risk assessment to evaluate a benchmark contingency of the project cost.