• Title/Summary/Keyword: ad-hoc

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Calculation of Total Benefit by the Contingent Valuation Method for Cost-Benefit Analysis: Focusing on Income and Distance-Decay Effects (비용편익분석을 위한 조건부가치측정법에서의 총편익 산정: 소득효과 및 거리-소멸 효과를 중심으로)

  • Lee, Jongyearn
    • KDI Journal of Economic Policy
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    • v.36 no.1
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    • pp.43-80
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    • 2014
  • This study suggests a model for calculating total benefit rigorously to use the contingent valuation method (CVM) in cost-benefit analysis (CBA). Estimating households' willingness to pay through survey method, the study attempts to demonstrate if a respondent's income and the distance between a respondent's residence and the location of a target facility affect her willingness to pay. The estimation results from a structural model show that income and distance-decay effects exist and that the calculated total benefit varies largely when these effects are ignored. The study emphasizes the effects of income and distance-decay on the total benefit must be carefully considered in using CVM for CBA. Even though the total project cost is precisely estimated, the benefit/cost (B/C) ratio may differ largely when the total benefit is not correctly calculated. Also, an ad hoc model generates significantly different estimates from the utility difference model this study adopted. The difference in estimates suggests that the total benefit has to be estimated by a structural model. Finally, simulations are performed to check the validity of the model as well as to predict consequences when income and distance-decay effects are not properly treated. The results from simulations reveal it is not desirable to ignore those effects considering the perspectives of balanced regional development.

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System Throughput of Cognitive Radio Multi-hop Relay Networks (무선인지 멀티홉 릴레이 네트워크의 시스템 스루풋)

  • Hassan, I.;Rho, Chang-Bae;Song, Ju-Bin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.4
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    • pp.29-39
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    • 2009
  • The need for radio spectrum is recently considered as a huge hurdle towards the rapid development of wireless networks. Large parts of the spectrum are allocated to licensed radio services in proprietary way. However, enormous success of the wireless services and technologies in the unlicensed bands has brought new ideas and innovations. In recent years cognitive radio has gained much attention for solving the spectrum scarcity problem. It changes the way spectrum is regulated so that more efficient spectrum utilization is possible. Multi-hop relay technology on the other hand has intensively been studied in the area of ad hoc and peer-to-peer networks. But in cellular network, only recently the integration of multi-hop capability is considered to enhance the performance significantly. Multi-hop relaying can extend the coverage of the cell to provide high data rate service to a greater distance and in the shadowed regions. Very few papers still exist that combine these methods to maximize the spectrum utilization. Thus we propose a network architecture combining these two technologies in a way to maximize the system throughput. We present the throughput capacity equations for the proposed system model considering various system parameters like utilization factor by the primary users and primary users' transmission radius and through extensive numerical simulations we analyze the significance of work.

Hybrid Authentication Scheme for Mobile Multi-hop Relay in IEEE 802.16j (IEEE 802.16j기반의 모바일 멀티 홉 릴레이에서의 혼합형 인증 기법에 대한 연구)

  • Lee, Yong;Lee, Goo-Yeon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.10
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    • pp.127-136
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    • 2007
  • It is easy to install and maintain a mobile multi-hop wireless network due to its self-organizing characteristics. However it has security weakness of the authentication of mobile multi-hop relay stations. Specially, the mobile multi-hop relay network in the IEEE 802.16j has the additional security weakness caused by the requirement of backward compatibility for mobile stations of the conventional IEEE 802.16 system. In this paper, we propose a novel mutual authentication scheme applicable to IEEE 802.16j-based mobile multi-hop relay network architecture. The scheme is able to resolve the initial trust gain problem of a multi-hop node at its entry to the network, the problem of rogue mobile multi-hop node and the problem of hop-by-hop authentication between multi-hop nodes. Effectively, the scheme is a hybrid scheme of the distributed authentication method and the centralized authentication method which have been considered to be deployed in the wireless ad-hoc network and the wireless network connected to wired authentication servers, respectively. Also, we analyze the effectiveness of the proposed hybrid authentication method.

The Recent Practice of Evaluation of Government-sponsored Research Institutes(GRIs) in Korea : From Retrospective to Forward-looking perspective (이공계 정부출연(연) 기관평가모형개발 및 적용사례 연구)

  • 이철원;현재호
    • Proceedings of the Technology Innovation Conference
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    • 1998.06a
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    • pp.131-163
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    • 1998
  • The interest in the evaluation of government-sponsored research institutes (GRIs) has increased markedly in Korea in 1990s; this is mainly because of the increasing needs 1) to improve the quality of R&D at GRIs, and 2) to reorient the GRIs' strategic position in Korean national innovation systems due to the enhancement of R&D capabilities of private companies and universities during last decade. As a first attempt to diagnose the managerial and strategic issues of GRIs, a Multi-Ministerial Evaluation Committee was established as an ad hoc task force under the Prime Minister's Office in 1991. According to the recommendations of the committee, the Ministry of Science and Technology (MOST) to which most of GRIs were affiliated, made it a rule to evaluate the annual performance of GRIs since 1992. This paper examines the recent experience of MOST's evaluation of Government-sponsored Research Institute in Korea. After several years'efforts of Science & Technology Policy Institute(STEPI) to build prospective evaluation systenL MOST decided to apply two supplementary approaches for the evaluation of GRIs; one is summative annual evaluation and the other is formative 3-year evaluation. The annual evaluation system that is designed as a temporary measure is to monitor and to guide the self-evaluation activities of GRIs. In the process of annual evaluation, MOST tries to minimize its direct involvement, and allows each GRI to develop self-evaluation system that is most appropriate for the unique characteristics of the institute. If there exist urgent issues under scrutiny, however, it can be incorporated and examined by a group of external experts as special issues in the annual evaluation system. The aim of 3-year evaluation is both to examine the past performance of each GRI and to investigate whether the strategic role of each GRI is viable in the future. Its major focus, however, lies not on auditing past performance but on strengthening future strategic position of each GRI. The MOST designates a group of evaluation experts with appropriate knowledge and competence as members of the General Evaluation Committee for one year. With the help of STEPI, a specialized research institute for R&D evaluation, the General Evaluation Committee develops methodology and procedures for the actual evaluation of GRIs. Based on the evaluation reports and recommendations from the General Evaluation Committee, the MOST develops various policy measures for strengthening GRIs.

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A Proposal for the Invigoration of Maritime Arbitration (해사중재 활성화를 위한 전제조건에 관한 논의)

  • Lee, Jung-Won
    • Journal of Arbitration Studies
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    • v.22 no.3
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    • pp.141-163
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    • 2012
  • In Korea, although nearly all maritime arbitration cases are dealt with by the Korean Commercial Arbitration Board (KCAB), the total number of cases that are referred to the KCAB is relatively small compared with the total number of maritime cases that occur in Korea. There may be reasons why maritime arbitration is not utilized more in Korea. However, of the above reasons, the superseding one may be that there is still a lack of confidence in the credibility and foreseeability of maritime arbitration in Korea. To expand the use of maritime arbitration in Korea, it is essential that the base surrounding maritime arbitration be expanded. In addition, it is also necessary that specialists receivetraining in maritime law. In this context, it is strongly recommended that maritime and admiralty law be taught in law schools and be included as a regular subject on the Korean bar exam. Additionally, to promote maritime arbitration, a rule should be introduced allowing for shortened arbitration proceedings in Korea. Although Chapter 8 of the KCAB Arbitration Rules provide for "Expedited Procedure," this process alone is not because the rules for Expedited Procedure generally apply in arbitration cases where both parties have agreed in a separate agreement to follow the procedures provided or in any domestic arbitration valued atless than 100,000,000 Korean won. Therefore, the KCAB Arbitration Rules for Expedited Procedure must be reformed to encompass international arbitrations. Additionally, experts who are experienced in the maritime sector should be elected as arbitrators. Given the factthat a fair number of arbitration cases can be characterized as international, it is important that businesspersons who are very fluent in English be appointed as arbitrators in order to increase the reliability of maritime arbitration in Korea and save costs. Meanwhile, because lawyers and scholars constitute a considerable portion of KCAB arbitrators, commercial persons from relevant industries should be enlisted as arbitrators. Even though there are arguments for the establishment of an independent maritime arbitration board in Korea, establishment of a separate maritime arbitration board will not directly guarantee the prosperity of maritime arbitration in Korea. Instead of instituting a new maritime arbitration board, it is better that a reorganized KCAB modify existing arbitration proceedings to make them faster and more economical if maritime arbitration is to prosper. In this regard, ad-hoc arbitration would be an option for speedy and thrifty maritime arbitration. Finally, to gain the confidence of domestic and foreign parties, we cannot ignore the importance of advertising the specialties and qualifications of the KCAB and its personnel among business entities.

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Ubiquitous u-Health System using RFID & ZigBee (RFID와 ZigBee를 이용한 유비쿼터스 u-Health 시스템 구현)

  • Kim Jin-Tai;Kwon Youngmi
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.1 s.343
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    • pp.79-88
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    • 2006
  • In this paper, we designed and implemented ubiquitous u-Health system using RFE and ZigBee. We made a wireless protocol Kit which combines RFE Tag recognition and ZigBee data communication capability. The software is designed and developed on the TinyOS. Wireless communication technologies which hold multi-protocol stacks with RFID and result in the wireless ubiquitous world could be Bluetooth, ZigBee, 802.11x WLAN and so on. The environments that the suggested u-Health system may be used is un-manned nursing, which would be utilized in dense sensor networks such as a hospital. The the size of devices with RFID and ZigBee will be so smaller and smaller as a bracelet, a wrist watch and a ring. The combined wireless RFID-ZigBee system could be applied to applications which requires some actions corresponding to the collected (or sensed) information in WBAN(Wireless Body Area Network) and/or WPAN(Wireless Person Area Network). The proposed ubiquitous u-Health system displays some text-type alert message on LCD which is attached to the system or gives voice alert message to the adequate node users. RFE will be used as various combinations with other wireless technologies for some application-specific purposes.

Analysis of the Durban Climate Summit and Its Implications to Climate Policies of Korea (제17차 유엔 기후변화 더반 당사국 총회의 평가와 정책적 시사점)

  • Park, Siwon
    • Journal of Environmental Policy
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    • v.11 no.3
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    • pp.149-170
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    • 2012
  • The United Nations Climate Change Conference, Durban 2011, ended on December 12, 2011, 36 hours over its schedule, delivering the Durban Package, which consisted of, inter alia, the extension of the period for Kyoto Protocol term and the launch of Ad-hoc working Group on the Durban Platform for Enhanced Action. Despite the positive progress made in Durban, the future of post-2012 climate regime still seems cloudy. Before the Durban conference, some of Annex I countries with emissions reduction commitment under the Kyoto Protocol's first commitment period openly declared their intention not to participate in the second one, reducing the effectiveness of Durban agreement. Parties to the conference have a long list of difficult issues disturbing the materialization of the new legal agreement in 2020 such as level of mitigation targets of individual countries and legal nature of their commitment. Given this uncertainty, the Korean government should reinforce its domestic climate policies rather than settling in the fact that it remains as a non-Annex I county party under the Durban Agreement due to the extension of the Kyoto Protocol period. Domestically, it needs to continue to raise the public awareness for rigorous climate policies to transit its economy to low carbon pathway which reduces the country's dependency on fossil fuel in the long term. It is also important to implement cost effective climate policies to cope with domestic resistance and international competitiveness. Internationally, its priority would be working for trust-building in the on-going negotiation meetings to encourage meaningful participation of all parties.

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Model for the Connection-Time of Vehicle-to-Mobile RSU (V2MR) Communications Near a Bus Station (버스 정류소 주변에서 자동차-이동기지국 (V2MR) 통신의 연결시간에 대한 성능분석모형)

  • Jeong, Han-You;Purnaningtyas, Magdalena Trie;Nguyen, Hoa-Hung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.12
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    • pp.1969-1977
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    • 2016
  • We study the connection time of vehicle-to-mobile roadside unit (V2MR) communications which can reduce the significant cost of the fixed RSU by installing a gateway of mobile network into a transit bus called the mobile RSU. In the V2MR communications, the connectivity of a commute vehicle can be improved via ad-hoc connection to a nearby mobile RSU. In this paper, we present a new analysis model to estimate the connection time between a commute vehicle and a mobile RSU, when there is a bus station in the overlapping route. Since the connection time between two vehicles is highly dynamic and unpredictable, our analysis will provide a fundamental basis of connection-time estimation of V2MR communications. Numerical results obtained from VEINS simulation show that our analysis can estimate the connection time of V2MR communications with the average error below 1.0 percent. Moreover, we show that the average connection time of V2MR communications can be extended to approximately 3.85 times of that of V2R communications.

An Indirect Localization Scheme for Low- Density Sensor Nodes in Wireless Sensor Networks (무선 센서 네트워크에서 저밀도 센서 노드에 대한 간접 위치 추정 알고리즘)

  • Jung, Young-Seok;Wu, Mary;Kim, Chong-Gun
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.1
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    • pp.32-38
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    • 2012
  • Each sensor node can know its location in several ways, if the node process the information based on its geographical position in sensor networks. In the localization scheme using GPS, there could be nodes that don't know their locations because the scheme requires line of sight to radio wave. Moreover, this scheme is high costly and consumes a lot of power. The localization scheme without GPS uses a sophisticated mathematical algorithm estimating location of sensor nodes that may be inaccurate. AHLoS(Ad Hoc Localization System) is a hybrid scheme using both GPS and location estimation algorithm. In AHLoS, the GPS node, which can receive its location from GPS, broadcasts its location to adjacent normal nodes which are not GPS devices. Normal nodes can estimate their location by using iterative triangulation algorithms if they receive at least three beacons which contain the position informations of neighbor nodes. But, there are some cases that a normal node receives less than two beacons by geographical conditions, network density, movements of nodes in sensor networks. We propose an indirect localization scheme for low-density sensor nodes which are difficult to receive directly at least three beacons from GPS nodes in wireless network.

Design and Analysis of Ubiquitous Social Network Management Service Model: u-Recruiting Service Model (유비쿼터스 사회연결망관리 서비스 모델 설계 및 분석: u-구인 구직 서비스 모델을 중심으로)

  • Oh, Jae-Suhp;Lee, Kyoung-Jun;Kim, Jae-Kyeong
    • Information Systems Review
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    • v.13 no.1
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    • pp.33-59
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    • 2011
  • Although online social network services widely used in human networking and recruiting industries, it is showing off its limitations in followings-it's hard to reach the status of seamless connection between offline and online; the incompletion and low credibility of the information came from non-face-to-face profile exchange; and the restraint of user autonomy due to centralized control. This paper defines the ubiquitous social network management which enables the seamless real-time face-to-face social interactions of the users based on WPAN (Wireless Personal Area Network) who share the same interest in real word and deduces a ubiquitous social network management framework based on it. As an instance of ubiquitous social network management, u-Recruiting service model will be designed and analyzed. The Analysis using the business model will be followed by the possible scenario of service model. The role, value proposition and potential benefits of the each participants in this service model and will be given as well. In order to evaluate relative advantages of the model suggested by this study, 6 cases will be compared.