• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.159-166
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• 2008

Recently, according to the rapid development of location positioning technology and wireless communications technology and increasement of usage of moving object data, many researches and developments on the real-time locating systems which provides real time service of moving object data stream are under proceeding. However, MO (Moving Object) DBMS used based system in the in these systems is the inefficient management of moving object data streams, and the existing DSMS (Data Stream Management System) has problems that spatio-temporal data are not handled efficiently. Therefore, in this thesis, we designed and implemented spatio-temporal DSMS for efficient real-time management of moving object data stream. This thesis implemented spatio-temporal DSMS based STREAM (STanford stREam dAta Manager) of Stanford University is supporting real-time management of moving object data stream and spatio-temproal query processing and filtering for reduce the input loading. Specifically, spatio-temporal operators of the spatio-temporal DSMS support standard interface of SQL form which extended "Simple Feature Specification for SQL" standard specifications presented by OGC for compatibility. Finally, implemented spatio-temporal DSMS in this thesis, proved the effectiveness of the system that as applied real-time monitoring areas that require real-time locating of object data stream DSMS.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.8-9
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• 2010

ATSC-M/H에서 main stream(좌영상)인 TS-M 패킷은 MPEG-2 전송 시스템을 기반이고, M/H stream(우영상)인 M/H 패킷은 RTP 기반의 전송방식을 사용한다. 이와 같이 dual-stream 시스템을 통해 좌우영상이 전송되는 경우에는 기존에 연구되었던 동종 스트림간의 동기화방안을 적용할 수 없다. 본 논문에서는 3차원 방송 서비스를 하기 위해 ATSC-M/H를 통해 전송되는 좌우영상간의 동기화 방안을 제안한다.

• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.15-22
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• 2016

This study aims to analyze the changes in the benthic macroinvertebrate community before and after a restoration project in a eutrophic stream. Species diversity and species richness increased at the points where the channel changed from standing water to running water. However, species diversity and richness decreased at the points where only riparian restoration was implemented, and the concentration of suspended solids increased, while biochemical oxygen demand and total phosphorus decreased and the concentration of dissolved oxygen increased. In such reaches, functional feeding groups went from collector-filterers to collector-gatherers, and habitat orientation groups changed from clingers to burrowers.

• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.487-492
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• 2003

To satisfy the requirements for QoS of Users using multimedia content stream service, it is required to control mechanism for QoS based on class priority, URFA classifies the user by two classes (super class, base class) and controls the admission ratio of user's requests by user's class information. URFA increases the admission ratio class and utilization ratio of stream server resources.

• ETRI Journal
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• v.31 no.6
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• pp.795-802
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• 2009

This paper presents the design of an advanced terrestrial digital multimedia broadcasting (AT-DMB) baseband receiver SoC. The AT-DMB baseband is incorporated into a hierarchical modulation scheme consisting of high priority (HP) and low priority (LP) stream decoders. The advantages of the hierarchical modulation scheme are backward compatibility and an enhanced data rate. The structure of the HP stream is the same as that of the conventional T-DMB system; therefore, a conventional T-DMB service is possible by decoding multimedia data in an HP stream. An enhanced data rate can be achieved by using both HP and LP streams. In this paper, we also discuss a time deinterleaver that can deinterleave data for a time duration of 384 ms or 768 ms. The interleaving time duration is chosen using the LP symbol mapping scheme. Furthermore, instead of a Viterbi decoder, a turbo decoder is adopted as an inner error correction system to mitigate the performance degradation due to a smaller symbol distance in a hierarchically modulated LP symbol. The AT-DMB baseband receiver SoC is fabricated using 0.13 ${\mu}m$ technology and shows successful operation with a 50 mW power dissipation.

• Journal of Environmental Science International
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• v.21 no.10
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• pp.1171-1179
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• 2012

Headwaters initiate material export to downstream environments. A nested headwater study examined the flux of dissolved constituents and water from a perennial stream and four ephemeral/intermittent streams in the Upper Gulf Coastal Plain of Mississippi. Water was collected during storm and baseflow conditions. Multiple linear regression was used to model constituent concentration and calculate flux. Event was the major source of water discharged from the ephemeral and intermittent streams however, baseflow was the major source for water discharged by the perennial stream during events. The perennial stream had an area weighted average yields of 10.1, 0.01, 1.03, 0.65 kg/ha/yr of DON (dissolved organic nitrogen), $NO_3^-$-N, $NH_4^+$-N and $PO_4^{-3}$, respectively while large variabilities existed between the ephemeral and intermittent streams. These findings highlight the importance of headwaters in protecting the low order drainage basins as a key to water quality within perennial streams.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.531-539
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• 2017

CAPTCHA is a verification scheme whether or not a human user has made a service request. Most CAPTCHAs that are based on text, image, or simple game suffer from vulnerability that can be compromised by automated attacks and stream relay attacks. To resist such attacks, CAPTCHA that utilizes human recognition as been suggested but it show poor usability for deploying in the Internet. We propose an Emerging Image Cue CAPTCHA that offers improved usability and resists stream relay attacks, as well. We also examine the usability of the proposed CAPTCHA and investigate the attack resistance by conducting user study and experiments on simulated network environment.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1379-1386
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• 2017

As the Internet of Things evolves, various IoT services are provided. IFTTT is an abbreviation for If This Then That and refers to a service that links different web-based services. This paper proposes a system that generates and manages rules that combine the possibility of IFTTT service and the real-time event processing according to the concept of IoT service. Conventional database-based data processing methods are burdened to process a lot of data of IoT devices coming in real-time. The IoT device's data can be classified into formal data such as the amount of power, temperature value and position information, and informal data such as video or image data. Thus, this system classifies the data stream of IoT devices coming in real-time using the CEP engine Esper into a file signature table, classifies the formal/informal data, and shows the condition of the device data defined by the user and the service to be provided by applying the service.

• Journal of the Korean Society of Earth Science Education
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• v.6 no.3
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• pp.235-241
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• 2013

The purpose of this study is to find out eco-friendly attitude and level of knowledge about environment of pre-service elementary teachers and find relationship between these. In this study, we investigate and analyse with surveys about eco-friendly attitudes and environmental knowledge questionnaire targeting the 2nd semester of 2013 32 people of fast stream class 2nd grade. Also, we analyzed correlation between environmental knowledge and the test results of eco-friendly attitudes. Results for the analysis are as follows. First, pre-service elementary teachers' average of eco-friendly attitudes test result is 'cognitive area(60.22)> definitional area(53.69)> behavioral area(52.72)'. These results are re-service elementary teachers are knowledgeable about the environment, but they are passive at the execution act about environment. Second, the average of pre-service elementary teachers' environmental knowledge result is the highest to the protect the environment, for the average(26.25). It is interpreted that they acquired the most the knowledge related to the conservation of the environment. Third, It is no significant correlation between pre-service elementary teachers' eco-friendly attitudes and environmental knowledge. It means that although they acquired a lot of knowledge related to the environment, it is not affected to environmental friendly attitude putting ideas into action about environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.107-118
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• 2011

This paper shows a u-Health management system in user's Life environment, which is different from previous ones by enterprises. It's designed for users(citizens) and service provider(especially providing medical service). This paper is discussing on the proof on the service model being operated near the Tancheon stream in the city of Sung-nam. To maximize users' satisfaction, this service has been designed on four disciplines(so easy, so simple, well-customized, funny feedback) in the viewpoint for users. Its algorithm has 4 levels which are measurement, prescription, monitoring and feedback. In the system. there are HCBs(health check boothes) checking out status and assessment of users, customized health prescription customized a health management service prescription engine, exercise programs customized on exercise equipments near the stream and monitoring system.