• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.683-693
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• 2012

In this study we investigated the factors determining people's decision on whether to subscribe to private health insurance, on how many private health insurances they subscribe to and the average amount of monthly payment from subscribers of private health insurances. For analysis, logistic regression analysis and multiple linear regression analysis were conducted on the sample of 8,167 people using 2008 Korean Longitudinal Study of Ageing(KLoSA) data. From the analysis, whether to enroll in private health insurance is found to be greatly influenced by population and socioeconomic factors as well as regular exercise, smoking, cognitive function scores, subjective health status, hospitalization, the number of outpatient services, free primary health screenings benefits. We also found that number of private health insurances purchased is affected by age, household income, subjective health status, drinking, free primary health screenings benefits and that the average amount of monthly payment for private health insurances purchased is influenced by age, marriage status, economic activities status, subjective sense of hierarchy, household income, drinking, hospitalization. This study is expected to contribute to show the healthy role of private health insurance so that the desirable direction in expansion of health security policy in Korea can be explored further.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.187-193
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• 2015

The ICT healing platform sets a couple of goals including preventing chronic diseases and sending out early disease warnings based on personal information such as bio-signals and life habits. The 2-step open system(TOS) had a relay designed between the healing platform and the storage of personal health data. It also took into account a publish/subscribe(pub/sub) service based on large-scale connections to transmit(monitor) the data processing process in real time. In the early design of TOS pub/sub, however, the same buffers were allocated regardless of connection idling and type of message in order to encode connection messages into a deflate algorithm. Proposed in this study, the dynamic buffer allocation was performed as follows: the message transmission type of each connection was first put to queuing; each queue was extracted for its feature, computed, and converted into vector through tf-idf, then being entered into a k-means cluster and forming a cluster; connections categorized under a certain cluster would re-allocate the resources according to the resource table of the cluster; the centroid of each cluster would select a queuing pattern to represent the cluster in advance and present it as a resource reference table(encoding efficiency by the buffer sizes); and the proposed design would perform trade-off between the calculation resources and the network bandwidth for cluster and feature calculations to efficiently allocate the encoding buffer resources of TOS to the network connections, thus contributing to the increased tps(number of real-time data processing and monitoring connections per unit hour) of TOS.

• 전자공학회논문지 IE
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• v.45 no.1
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• pp.24-30
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• 2008

In this paper, Digital MultiTone(DMT) is an emerging multi-carrier modulation scheme, which has been adopted for VDSL(Very high speed Digital Subscribe Line). A problem of DMT is its sensitivity to frequency offset between the transmitted and received carrier frequencies. This frequency offset introduces inter-carrier interference(ICI) in the DMT symbol. This paper is proposed an ICI cancelation scheme using Kalman Filtering. The performance of the proposed method is compared with conventional methods in terms of bit error rate performance, bandwidth efficiency, and computational complexity. Through simulations, it is shown that for high values of the frequency offset and for higher order modulation schemes, the EKF(Enhanced Kalman Filtering) method perform better than the others.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1179-1185
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• 2013

Trend of next generation satellite communication network is distribution and enlargement of network structure with increased network terminals, and traffic which use satellite communication is increasing and frequently occurring. Under specific satellite communication environment that various communication device dynamically forms a network domain and frequently exchanges the data, data-centric publish/subscribe data exchange is more suitable than server/client data exchange. So, this paper analyze DDS performance for application of DDS standard to distribution network management system which aims to efficiently manage limited satellite resource, and also this paper covers comparative study on DDS and SNMP(server/client data exchange). Study compares DDS and SNMP using OPNET, and result of study is analyzed from a network layer performance perspective.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.1-6
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• 2014

This paper proposes a mobile content curation service to collect various online/offline publications. The company publishes one-time topic information to a broker server in advance and customer curates topic information on a mobile device by requesting it. The main characteristics of the proposed service are: it is based on request/response model rather than existing publish/subscribe model, can easily specify topic information by input string without QR code or audio recognition, and retrieves all of topic information anywhere anytime by storing it on mobile device. This service can be used for second screen campaign for TV and various online/offline events.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1369-1378
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• 2017

Pub/Sub (Publish/Subscribe) paradigm is a simple and easy to use model for interconnecting applications in a distributed environment. In general, subscribers register their interests in a topic or a pattern of events and then asynchronously receive events matching their interest, regardless of the events' publisher. In order to build a low latency lightweight pub/sub system for Internet of Things (IoT) services, we propose a GQSFPS (Group Quorum System-based Fog Pub/Sub) system that is a core component in the event-driven service oriented architecture framework for IoT services. The GQSFPS organizes multiple installed pub/sub brokers in the fog servers into a group quorum based P2P (peer-to-peer) topology for the efficient searching and the low latency accessing of events. Therefore, the events of IoT are cached on the basis of group quorum, and the delay-sensitive IoT applications of edge devices can effectively access the cached events from group quorum fog servers in low latency. The performance of the proposed GQSFPS is evaluated through an analytical model, and is compared to the GQPS (grid quorum-based pud/sub system).

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.100-105
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• 2008

EPCglobal은 기업 간의 물류 활동 촉진과 글로벌 유통물류 시스템 구축을 위하여 EPCglobal Architecture Framework을 제시 하였다. EPCglobal Architecture Framework의 한 구성 요소인 EPCIS(Electronic Product Code Information Services)는 EPC, 시간, 위치와 같은 물류 관련 정보에 대해 저장 및 검색 서비스를 제공한다. EPCIS는 단발성 질의(poll)와 연속 질의(subscribe) 검색 서비스를 제공한다. EPCIS의 연속 질의는 시스템 자동화 및 재고 관리, 공급망 관리를 위해 다양한 응용에서 활용이 가능하다. 일반적으로 연속 질의 처리를 위해서는 등록된 연속 질의와 입력된 데이터를 순차적으로 비교하는 Sequential Matching 기법을 사용한다. Sequential Matching기법은 등록된 연속 질의 수가 증가 할 경우 많은 부하를 발생 시키고, 이로 인해 시스템 처리 지연이 발생한다. 본 논문에서는 EPCIS의 시공간 EPC 데이터의 연속질의 처리 성능 향상을 위해 선택률 기반 효율적인 연속질의 처리 기법을 제안한다. 13차원의 도메인을 여러 개의 질의 색인으로 구성하고, 등록된 질의 정보를 기반으로 선택률을 계산한다. 선택률에 의해 변경되는 동적 질의 실행 계획을 제안함으로써, EPCIS에서 시공간 EPC 데이터의 연속질의 처리에 대해 평균 60%의 성능이 향상이 가능하도록 하였다.

• The Journal of Society for e-Business Studies
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• v.12 no.4
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• pp.29-36
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• 2007

Recently, Jaiswal et al. proposed a protocol to improve the multi-agent negotiation test-bed which was proposed by Collins et al. Using publish/subscribe system, time-release cryptography and anonymous communication, their protocol gives an improvement on the old one. However, it is shown that the protocol also has some security weaknesses: such as replay data attack and DOS (denial-of-service) attack, anonymity disclosure, collusion between customers and a certain supplier. So proposed protocol reduces DOS attack and avoids replay data attack by providing ticket token and deal sequence number to the supplier. And it is proved that the way that market generates random number to the supplier is better than the supplier do by himself in guaranteeing anonymity. Market publishes interpolating polynomial for sharing the determination process data. It avoids collusion between customer and a certain supplie

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.65-70
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• 2004

The method of broadcast encryption has been applied to the transmission of digital information such as multimedia, software, and paid TV on the open network. In this broadcast encryption method, only previously authorized users can gain access to digital information. When broadcast message is transmitted, authorized users can first decode the session key using the previously given private key and get digital information using this session key. This way, users retrieve a message or a session key using the key transmitted by broadcasters. For their part, broadcasters need to generate and distribute keys. Broadcasters should also carry out efficient key renewal when users subscribe or un-subscriber. In this paper use a broadcast, and present the DRM model, using that look into the requirement about the contents and apply also the concept of a broadcast encryption. We offer the authority to copy as the number of reproduction to want to the user, and the low so that we were convenient because we used.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.230-232
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• 2011

Owing to the advent of digital devices which equipped with GPS, such as smartphone and tablet pc, a number of LBSNS applications have been released and even SNS applications serve various Location-Based Services. In twitter's case, the news of interesting area is provided to user not by being subscribed them automatically, but by being searched on web-site. This paper describes the system designed for users want to subscribe the local news without procedure like searching using operators. This system uses PBSM(Partition Based Spatial-Merge Join) which has no index for batch processing and against a massive query. The results from Spatial Join are stored in Materialized View then provided to user.