• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.27-33
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• 2010

One of the most critical success factor in introducing and operating an integrated information system is the performance management. In this study, we propose some SQL tuning techniques, applicable to optimize the performance of relational database systems. We showed effectiveness of the techniques by applying to a database system of a medium scale company.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.530-531
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• 2008

Recently, navigation system is widely accepted for many car users for its versatile facilities. In Korea, many navigation system include DMB (digial multimedia broadcasting) which is mobile TV broadcasting system standard in Korea. However, there is little works on the navigation systems for the European market where the DVB-T can be used for the multimedia broadcasting. Thus, in this work the navigation system with DVB-T is developed and tested for European market resulting increased profits for the navigation manufacturers.

• Journal of Information Processing Systems
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• v.6 no.4
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• pp.575-596
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• 2010

Video-on-Demand services are increasing rapidly nowadays. The load on servers can be very high, even exceeding their capacity. For popular contents, we can use a Periodic Broadcast (PB) strategy using multicast to serve all clients. Recent development of PB uses multiple channels broadcasting for segments of movies in certain patterns, so that users only need to wait for a small segment to start the service. However, users need higher download capacity to download multiple segments at a time. In order to compensate for this, a proxy server can help to reduce download bandwidth requirements by holding some segments for a certain time. This research will focus on more recent PB schemes that couldn't be covered by previous Proxy-Assisted Periodic Broadcast strategies.

• The Journal of Information Systems
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• v.9 no.1
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• pp.87-108
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• 2000

The tourist industry is expecially one of the successful areas for the application of electronic commerce because it is an information-intensive and consumer-oriented industry where information and services play a large part in transaction processes. A electronic tourism market which integrates tourist information systems, reservation systems, and real-time broadcasting systems based on the Internet Web was developed by a collaborative team of Dongguk University and Daou Tech. Inc. with sponsorship of Kyongbuk province and Minister of Information Communications of Korea. Based on the development case of the system, this paper proposes development and operations strategies of electronic market in the tourist industry. The paper reviews the development strategies in the perspective of potential travelers, technology, cooperation among players, and development methodology. The paper also discusses strategies which are able to be employed as the guideline in order to operate the system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.1
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• pp.19-24
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• 2009

In these days, security threat is ever increasing as computer systems and networking is everywhere. This paper is on the development of security scanner using search engine, with which site managers can easily check security vulnerability on their systems. Our security server automatically collects security-related information on the Internet, and indexes them in the database. To check the vulnerability of a customer server, the client system collects various system-specific information, and sends necessary queries to our security server for vulnerability checking. Up-to-date and site-specific vulnerability information is retrieved through the viewer, which allows the customer effectively to check and respond to security threat on client systems.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2007.02a
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• pp.64-67
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• 2007

본 논문은 EPG(Electronic Program Guide) 및 TV-Anytime 메타데이터를 이용하여 TV 시청자에게 개인형 편성 방송 프로그램 서비스를 제공 하기 위한 시스템의 설계 및 구현에 관한 것이다 기존의 사용자 맞춤형 방송 서비스는 TV 시청자가 시청하기 원하는 독립적인 프로그램 수준의 방송을 TV시청자가 원하는 시간에 선택하고 시청할 수 있는 서비스에 초점이 맞추어져 왔다. 본 논문에서는EPG메타데이터 및 세그먼트 메타데이터를 활용하여 TV시청자가 원하는 시간에 시청하기 원하는 프로그램 수준의 방송뿐만 아니라, 해당 프로그램의 시청하기 원하는 일부 방송들을 편성하고, 편성된 세그먼트 방송을 TV시청자의 시간 스케줄에 따라 시청할 수 있는 서비스 모델을 제시하고 구현 하였다.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.45-51
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• 2014

Luby transform (LT) codes are a class of ratelss codes, and they have capability of generating infinite length of parities with a given information length. These rateless codes can be effectively utilized to provide broadcasting and multicasting services where each user is in a different channel condition. For this reason, there have been a number of researches on the application of rateless codes for satellite systems. In this paper, by considering the current research status on rateless codes, we present VHLD implementation results of LT codes, for future hardware implementation for satellite systems. The results demonstrated in this paper can be utilized as a basic information on efficient utilization of rateless codes in the future satellite systems.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.261-269
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• 2023

We propose to design a Holochain-based security and privacy protection system for resource-constrained IoT healthcare systems. Through analysis and performance evaluation, the proposed system confirmed that these characteristics operate effectively in the IoT healthcare environment. The system proposed in this paper consists of four main layers aimed at secure collection, transmission, storage, and processing of important medical data in IoT healthcare environments. The first PERCEPTION layer consists of various IoT devices, such as wearable devices, sensors, and other medical devices. These devices collect patient health data and pass it on to the network layer. The second network connectivity layer assigns an IP address to the collected data and ensures that the data is transmitted reliably over the network. Transmission takes place via standardized protocols, which ensures data reliability and availability. The third distributed cloud layer is a distributed data storage based on Holochain that stores important medical information collected from resource-limited IoT devices. This layer manages data integrity and access control, and allows users to share data securely. Finally, the fourth application layer provides useful information and services to end users, patients and healthcare professionals. The structuring and presentation of data and interaction between applications are managed at this layer. This structure aims to provide security, privacy, and resource efficiency suitable for IoT healthcare systems, in contrast to traditional centralized or blockchain-based systems. We design and propose a Holochain-based security and privacy protection system through a better IoT healthcare system.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.193-194
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• 2008

In this paper, we compare the performance of the channel estimation methods with various interpolators for ISDB-T which is Japanese digital television terrestrial broadcasting systems. In this computer simulations, various interpolation methods are applied and the entire channel estimation performances according to the way of interpolation are compared.

• International Journal of Internet, Broadcasting and Communication
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• v.5 no.2
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• pp.1-4
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• 2013

With the recent development of the ubiquitous computing technology, there are increasing interest and research in technologies such as sensors and RFID related to information recognition and location positioning in various ubiquitous fields. Especially, RTLS (Real-Time Locating Services) dealing with spatio-temporal data is emerging as a promising technology. For these reasons, the ISO/IEC published RTLS standard specification for compatibility and interoperability in RTLS. Therefore, in this paper, we designed and implemented Spatio-temporal Query Processing Systems for efficiently managing and searching the incoming Spatio-temporal data stream of moving objects. Spatio-temporal Query Processing Systems's spatio-temporal middleware maintains interoperability among heterogeneous devices and guarantees data integrity in query processing through real time processing of unceasing spatio-temporal data streams and two way synchronization of spatio-temporal DBMSs. Web Server uses the SOAP(Simple Object Access Protocol) message between client and server for interoperability and translates client's SOAP message into CQL(Continuous Query Language) of the spatio-temporal middleware.