• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.131-132
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• 2017

CSMA/CA 기반 무선 네트워크에서 장치들은 패킷 충돌을 회피하기 위해 무선 채널을 타 장치가 사용 중인 것을 감지하면 데이터를 전송하지 않고 대기 (Backoff) 한다. 이 Backoff는 Contention Window (CW) 의 크기를 변경하고 Backoff 시간은 이 CW의 크기에 따라 확률적으로 결정된다. 따라서 CW의 크기는 무선 네트워크의 상태를 나타내는 중요한 지표가 될 수 있다. 본 논문에서는 상대적으로 넓은 공간에서 IEEE 802.11a 무선네트워크의 Access Point와 사용자들이 Poisson point process (PPP)를 기반으로 분포되어 Hidden Terminal이 존재할 수 있는 상황에서 CW의 크기 변화를 시뮬레이션을 통해 분석한다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (1)
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• pp.286-288
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• 2004

무선 통신의 발달로 언제 어디서나 누구와도 통신이 자유롭게 되었다 하지만, 무선 통신을 사용하게 됨으로써 통신 사용자와 액세스 포인트, 액세스 포인트와 서버(Server)가 통신을 할 경우 유선 네트워크와는 다른 인증 방식이 요구되었다. 무선 네트워크에서 사용자 인증을 위해 801.x EAP, SSID, CHAP 및 WEP를 이용한 다양한 인증 방식이 사용되고 있다. 본 논문에서는 사용자를 안전하게 인증할 수 있는 효율적인 인증 방법을 제안한다. 절기서는 기존의 PPP CHAP을 수정하여 인증 서버와 사용자간의 상호 인증을 할 수 있도록 했다. 또한 강한 일-방향 해시 함수(Strength One-Way Hash Function)을 사용하여 생성된 결과 값을 일회용 패스워드(One Time Password:OTP)로 사용하여 재공격(Reply Attack)을 방지했다.

• KDI Journal of Economic Policy
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• 제41권3호
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• pp.39-75
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• 2019

An emphasis on public-private partnership (PPP) in the regulatory policy process can overcome the challenges hindering regulatory effectiveness with the emergence of fast developing technologies and new industries. This study attempts to evaluate quantitatively different aspects of institutional settings of South Korean regulatory policy in terms of stakeholder engagement as PPP, using evidence-based data released by the OECD. From the results of the principal component analysis, South Korea can be evaluated as being at a very good level overall in its institutional establishment. Nevertheless, the fact that the outcome of regulatory reforms in South Korea is still insufficient compared with this well-established system suggests that the country should concentrate on improving system operation. Consequently, this study makes policy suggestions to improve regulatory effectiveness through PPP by supplementing the facets that are well-equipped but not feasible with respect to regulatory policy cycle, regulatory governance, regulatory method, and conflict resolution.

• Journal of Positioning, Navigation, and Timing
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• 제10권1호
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• pp.29-34
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• 2021

Recently, many studies have considered the effect of atmospheric pressure loading (APL) on precise global navigation satellite system (GNSS) data processing. The APL deforms the Earth's crust. It can often exceed 10 mm in radial displacement. In this study, we analyze the APL effect on Multi-GNSS kinematic precise point positioning (PPP). In addition, observations received at two GNSS reference stations (DAEJ and SUWN) in South Korea were processed. The absolute position changes for the two stations were compared to before and after applying the APL effects from January 1 to February 29, 2020. The crust of South Korea was most affected by the APL in the up direction. With the APL model, the difference in daily position changes was mostly within 4 mm in the radial direction. On the other hand, the horizontal components (east-west and north-south) were relatively less affected than the radial component.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.694-703
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• 2007

This paper stems from information accumulated from extensive literature review, a pilot study and a formal interview for an ongoing research on housing privatization implemented by the government-linked companies in Malaysia. Through extensive literature review, issues pertaining to housing privatisation were identified. Expectations of public sector, outcome of housing privatisation and factors influencing such outcome have also been tentatively confirmed through pilot study and an ongoing postal survey. A formal interview with a project director of independent Public-private partnerships (PPP) organization in UK has also inspired some useful lessons for the local housing industry. Different modalities of PPP from various countries show that while housing privatization pose several problems, mitigating them is possible through appropriate strategies.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.729-738
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• 2007

The Public Private Partnership/Private Finance Initiative (PPP/PFI) schemes have made the private sector become a major participant involved in the development of infrastructure systems along with the government. Due to more integrated efforts among project participants and longer concession period, PPP/PFI projects are inherently more complex and risky. It is therefore very important to proactively manage the risks involved throughout the project life cycle. Conventional risk management strategies sometimes ignore managerial flexibility in the planning and execution process. This paper starts with a revised risk management framework which incorporates the real option concept. Following the presentation of the framework, a new risk classification is proposed which leads to different ways of structuring options in a project according to the stage of the project life cycle. Finally, the paper closes by discussing other issues concerning option modeling and negotiation.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.344-351
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• 2013

Private participation on public infrastructures projects is being promoted by governments of several developing countries, among them Colombia. As a result, several advantages such as service delivery efficiency, technology application and faster execution of the projects have been recognized. Hence, the Colombian Government is looking for schemes that allow the private investment in projects like hospitals, schools, prisons and public edification. In this paper, experiences in PPP from other countries were analyzed and adjusted to the Colombian environment. As a result, a model adapted to Colombia is presented, based on a well-developed case from Spain. The awarding process is defined by economic criteria, previous compliance of minimum technical exigencies. Once the infrastructure is operating, contractual periodical payments will be done, based on the performance of the facility.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.358-359
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• 2003

Organic light-emitting device have attracted much interest due to their potential application in large area, full color, flat panel displays. Poly(p-phenylene)(PPP), as a blue light-emitting materials, have studied in our previous report. Thus, we selected poly(p-phenylene) (PPP) to fabricate the organic light-emitting filaments(OLEF) [1-2]. In this paper, we fabricated an organic light-emitting filaments(OLEF), which can be woven into fabric. The key concept was flexibility in one-dimensional structures. (omitted)

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2001년도 봄 학술발표논문집 Vol.28 No.1 (A)
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• pp.154-156
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• 2001

본 논문에서는 현재 무선으로의 전환에서 중요한 기술인 BlueTooth를 사용한 LAN access point에 대하여 연구하여 다른 모든 무선으로의 대안들 보다 블루투스가 우월함을 소개한다. 이를 위하여 블루투스 프로토콜 전체 스택에 대해서 살펴보고 Axis의 Linux LAN Access Profile을 응용하여 Windows로의 이식을 고안하고 이에 필요한 함수들을 제안한다. 또한 Windows로의 이식에 있어서 필요한 기술인 NDIS를 살펴본다. 아울러 Profile을 응용한 LAN Access Profile을 구현한 LAN Access Point를 구현한 후, 결론에서 불루투스 차기버전으로의 이식 문제와 RTOS로의 이식을 고려해본다.

• 디지털콘텐츠
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• 5호통권48호
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• pp.71-71
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• 1997