• Journal of KIISE:Information Networking
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• v.36 no.4
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• pp.360-368
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• 2009

Recently, broadband access networks have been competitively deployed all over the world with the development of various multimedia services for such a network. ETRI(Electronics and Telecommunications Research Institute) built the FTTH(Fiber-To-the-Home) service center to develop a next-generation equipment and a high-quality service/platform as well as to promote domestic industry in the field of optical communication. The FTTH service center has a variety of test equipments such as FTTH standard testbed for a BMT(bench mark test), a network operation center, and IPTV service equipments. Also, ETRI deployed a new type of commercial optical access networks cooperating with ISP(Internet Service Provider). This paper presents the performance evaluation of FTTH E-PON(Ethernet Passive Optical Network) system as a platform for TPS(Triple Play Service) based on QoS(Quality of Service) and QoE(Quality of Expericence) issues. This FTTH E-PON system is successfully demonstrated as an optical access network system by commercial network service provider and the FTTH service center of ETRI.

• Journal of Software Engineering Society
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• v.26 no.2
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• pp.45-52
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• 2013

A cloud computing service provider must assure Service Level Agreement (SLA) to provide reliable and consistent quality of service to a user. The SLA is a contract between the user and the service provider that connects to assure constant level such as availability to target provided service. The cloud computing is classified into IaaS, PaaS, and SaaS according to IT resources of the various cloud service. The existing SLA is difficult to reflect quality factors of service because it only considers factors about the physical Network environment. In this paper, we suggest the UDDI-based interchange process with the architecture and the specification language having a XML schema for the SLA specification. The quality requirements of SaaS are defined by a proposed specification language in the cloud environment. It is stored in the repository of a quality specification and exchanged on during the service binding time based on the exchange architecture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.445-466
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• 2022

As everything linking to the internet, people can subscribe to various services from a service provider to facilitate their lives through the Internet of Things (IoT). An obligatory thing for the service provider is that they should push the service data safely and timely to multiple IoT terminal devices regularly after the IoT devices accomplishing the service subscription. In order to control the service message received by the legal devices as while as keep the confidentiality of the data, the public key encryption algorithm is utilized. While the existing public encryption algorithms for push service are too complicated for IoT devices, and almost of the current subscription schemes based on push mode are relying on centralized organization which may suffer from centralized entity corruption or single point of failure. To address these issues, we design a secure subscription-push service scheme based on blockchain and edge computing in this article, which is decentralized with secure architecture for the subscription and push of service. Furthermore, inspired by broadcast encryption and multicast encryption, a new encryption algorithm is designed to manage the permissions of IoT devices together with smart contract, and to protect the confidentiality of push messages, which is suitable for IoT devices. The edge computing nodes, in the new system architecture, maintain the blockchain to ensure the impartiality and traceability of service subscriptions and push messages, meanwhile undertake some calculations for IoT devices with limited computing power. The legalities of subscription services are guaranteed by verifying subscription tags on the smart contract. Lastly, the analysis indicates that the scheme is reliable, and the proposed encryption algorithm is safe and efficient.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.12
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• pp.51-60
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• 2004

DAB(Digital Audio Broadcasting) is a new media service that can provide CD quality audio, various data service, interactive and high quality mobile communications through popular media such as terrestrial broadcasting, satellite, cable TV, and internet. In this paper, a new EPG(Electronic Program Guide) application model is proposed. The model is based on DAB and combines a DAB receiver and PCs so that it can take advantages of using various multimedia services and plenty of internet contents. The developed EPSD(EPG Provider System on DAB) has Web-based Server/Client structure and povides EPG functionalities to client PCs over internet. Therefore, the DAB receiver can be smaller and cheaper, and can develop abundant data services on internet. It can also provide high quality video services and be expected to become an important component in future home network systems.

• The Korean Journal of Emergency Medical Services
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• v.12 no.3
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• pp.27-41
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• 2008

Purpose : The purpose of this study was to supply basic data for the impact on the accuracy of basic CPR according to position and foot-board height of basic CPR provider. Methods : Study design was within - group design. Subjects were 25 EMT-P Students in K city. Interventions was basic CPR performed on a resuscitation manikin placed on a hospital bed, kneeling on the bed adjacent to the manikin. Data was analyzed using descriptive statistics and Friedman test. Results : In case of the basic CPR performed on a resuscitation manikin placed on a hospital bed, ventilation accuracy was the highest in less than 160 cm height, foot-board height : $34.2{\pm}1.48cm$, 91.4% and in 161-165 cm height, foot-board height : $26.0{\pm}2.14cm$, 88.4% and in 171-175 cm height, foot-board height : $23.0{\pm}1.41cm$, 91.3% and in the above 176 cm, kneeling on the bed, 95%. Chest compression accuracy was the highest in less than 160 cm height, foot-board height : $30.2{\pm}1.48cm$, 95.6% and in 161-165 cm height, kneeling on the bed, 97.6% and in 171-175 cm height, kneeling on the bed, 98.5% and in the above 176 cm, kneeling on the bed, 98.7% and foot-board height : $20.5{\pm}1.91cm$, 98.7%. Chest compression error was due to too weak : 2.0-35.4 times. There were ststistically significant differences in 191-195 cm group according to chest compression mean depths($x^2=10.824$, p = .013) and chest compression error (p = .040). Conclusion : In contrast to current guidelines, the position and foot-board height of basic CPR provider are very important to the accuracy of the basic CPR. Furthermore, we recommend that a using real time audiovisual feedaback system significantly improve the quality of chest compression and ventilation during resuscitation.

• Proceedings of the Korea Association of Information Systems Conference
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• 2003.11a
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• pp.276-287
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• 2003

21세기에 접어들면서 기업의 경영환경은 급속한 속도로 변화하고 있다. 이러한 급격한 환경변화 속에서 기업이 핵심역량에 집중하고 기업의 경쟁력을 극대화하기 위해 기업의 정보관련 시스템 및 어플리케이션을 아웃소싱하기 위해 사용하는 개념이 ASP 서비스이다. ASP 서비스는 기업내부에 정보시스템 전담 조직을 갖추지 않고서도 각종 소프트웨어를 저렴한 값에 사용할 수 있고, 기업 자체의 전산시스템 및 운영 전담인력이 필요없으며, 하드웨어 및 소프트웨어를 구입할 필요성이 없는 등 여러 가지 이점을 가지고 있어 최근들어 기업들로 하여금 큰 논의와 함께 많은 투자가 이루어지고 있다. 하지만 ASP 서비스의 개념이 비교적 최근에 등장한 개념이기 때문에 관련 연구들이 개념정립이나 도입 의사결정 요인에 관한 연구에 머무르고 있는 실정이다. 이러한 배경하에서 본 연구는 첫째, ASP 서비스에 대한 체계적인 연구를 통해 ASP 서비스의 개념에 대한 명확한 이해를 제공하고, 기업의 정보화 추진 방법으로서 ASP 서비스가 가지는 가능성을 분석해 보고 둘째, 기업이 ASP 서비스를 도입하고 운영함에 있어서 성공적인 수행에 어떠한 요인들이 중요한 영향을 미치는지 살펴보기 위해 개념적인 모형을 도출해 보고자 한다.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.151-161
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• 2002

This paper presents the business model and system functionalities of a B2B e-marketplace solution that not only can overcome some problems of the public e- marketplace, but also can be applicable to both public and private types of e-marketplaces. This solution is different from the most of the public e-marketplace solutions that their main sources of revenue are transaction commissions or transaction fees through the third-party intermediation. Instead, this solution provides an ASP (Application Service Provider) functionality for direct, dis-intermediated purchasing and sales-related transactions between suppliers and buyers. With this functionality, suppliers and buyers electronically commerce with each other without the disclosure of their transactions as well as transaction commissions.

• The Korean Journal of Health Service Management
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• v.4 no.1
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• pp.1-10
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• 2010

The purpose of this study is to investigate the effects of provider and consumer characteristics, and patient trust on relational commitment among healthcare customers of an university hospital, and to suggest some implications for improving customer relation management of hospitals. Data were collected from 250 patients of an university hospital located in Ulsan using structured self-administered questionnaire. Major result of the analysis is as follows: First, study variables are significantly varied by age and income among socio-economic factors. Second, assurance, and empathy among provider characteristics and customer satisfaction and reputation among consumer characteristics are found to be significant affecting factors on patient trust. Third, trust affects significantly both on re-visit and recommendation among relationship commitment, while reputation affects on re-visit and customer satisfaction and reputation affect on recommendation. Above results imply that relationship management strategy for enhancing patient trust is crucial to improve competitiveness of hospitals in turbulent competition environment.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.3
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• pp.180-190
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• 2006

We evaluate the economic value and the optimal investment timing of IMT-2000 in Korea, in the perspective of a service provider who owns the business license for IMT-2000, by using the real options analysis. The result clearly shows the project value with options is positive and delaying the investment is more favorable to the provider. Binomial lattice approach, in which we try to describe American call option and sequential compound option, and sensitivity analysis present the optimal decisions according to future states and enable the management to make decision strategically and proactively.

• ETRI Journal
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• v.34 no.1
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• pp.66-75
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• 2012

This paper proposes a privacy-preserving database encryption scheme that provides access pattern hiding against a service provider. The proposed scheme uses a session key to permute indices of database records each time they are accessed. The proposed scheme can achieve access pattern hiding in situations in which an adversary cannot access the inside of the database directly, by separating the entity with an index table and data table and permuting both the index and position where the data are stored. Moreover, it is very efficient since only O(1) server computation and communication cost are required in terms of the number of the data stored. It can be applied to cloud computing, where the intermediate entities such as cloud computing service provider can violate the privacy of users or patients.