• Journal of Information Technology Applications and Management
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• 제10권4호
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• pp.169-183
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• 2003

멀티미디어 시스템에서는 통상적으로 매우 큰 크기의 파일이 저장되고 재생된다. 이 파일들은 읽기 중심이며 재사용 가능성이 낮아 기존의 파일 시스템들이 가정하는 형태의 파일이 아니기 때문에 이런 파일이 자주 사용되는 멀티미디어 시스템의 경우 기존 파일 시스템의 성능은 그리 좋지 않다. 본 논문에서는 멀티미디어시스템을 위한 새로운 파일 시스템을 구현하였다. 성능 측정 결과 새 파일 시스템이 기존 파일 시스템인 Ext2, Ext3 보다 쓰기, 읽기, 쓰기/읽기 동시 수행에 있어서 각각 39.75% ∼ 40.67%, 36.48% ∼ 43.36%, 28.04% ∼ 32.60% 높은 성능을 나타내었다. 이 파일 시스템은 리눅스 상에서 구현되었으며 어렵지 않게 다른 운영 체제에도 적용이 가능하다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1213-1237
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• 2019

Vehicular Ad-hoc Network (VANET) facilities envision future Intelligent Transporting Systems (ITSs) by providing inter-vehicle communication for metrics such as road surveillance, traffic information, and road condition. In recent years, vehicle manufacturers, researchers and academicians have devoted significant attention to vehicular communication technology because of its highly dynamic connectivity and self-organized, decentralized networking characteristics. However, due to VANET's high mobility, dynamic network topology and low communication coverage, dissemination of large data packets (e.g. multimedia content) is challenging. Clustering enhances network performance by maintaining communication link stability, sharing network resources and efficiently using bandwidth among nodes. This paper proposes a mobility-based, multi-hop clustering algorithm, (MBCA) for multimedia content broadcasting over an IEEE 802.11p-LTE-enabled hybrid VANET architecture. The OMNeT++ network simulator and a SUMO traffic generator are used to simulate a network scenario. The simulation results indicate that the proposed clustering algorithm over a hybrid VANET architecture improves the overall network stability and performance, resulting in an overall 20% increased cluster head duration, 20% increased cluster member duration, lower cluster overhead, 15% improved data packet delivery ratio and lower network delay from the referenced schemes [46], [47] and [50] during multimedia content dissemination over VANET.

• 산업공학
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• 제17권4호
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• pp.466-471
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• 2004

In this paper, I develop a simple dynamic resource allocation algorithm that reduces the call blocking rate by improving the resource utilization of the WCDMA (Wideband Code Division Multiple Access) systems under multimedia service environment. Simulation results show that the proposed algorithm significantly reduces the blocking rate of high speed multimedia calls. The algorithm developed in this paper is currently working in the commercial WCDMA IMT-2000 system.

• ETRI Journal
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• 제24권3호
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• pp.247-250
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• 2002

In this paper, we propose three symbol syn-chronization schemes for Orthogonal Frequency Division Multiplex (OFDM) systems. The cyclic extension preceding OFDM symbols is of decisive importance for these schemes. The first scheme uses the phase-differential coding of the received OFDM signal. The second and the third schemes use the length of the received OFDM signal. All three schemes make symbol synchronization possible, even though there is a frequency off-set in the system. Simulation results show that these schemes can be used to synchronize an OFDM system over AWGN and multi-path fading channels.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1999년도 추계공동학술대회 논문집:21세기지식경영과 정보기술
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• pp.301-313
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• 1999

Recently, the rabid development of information technology has brought enormous changes in education. Consolidation of communications and multimedia technologies are enabling the new educational paradigm such as distance learning and virtual education. Furthermore, many studies in the education engineering field report that teaching using multimedia technologies more enhances students' performance than the traditional instructor-teaching method. However, little research regarding the education using multimedia has been done in the MIS filed. None of multimedia-related studies could be found in the top-ranked MIS journals published in Korea for the last five years, and only a few studies were found even worldwide. In this regard, the purpose of this study is to investigate which features of multimedia software are most important to enhance the teaching results of students. From the previous research, we found out the specific features of the educational multimedia software which are considered to affect the students'performance, and defined the research variables related to those educational software features. And, based on the constructivism and motivation theory of the education engineering field a theoretical research model and research hypotheses were developed. Perceived usefulness of the class and a student's perceived interests in the class were used as surrogate variables to measure teaching performance. Total 277 students participated separately in one of the two multimedia classes which have continued for three weeks. One was C programming language class and the other was multimedia CD-title development class. Each student listened for the multimedia session of the class using multimedia software and, at the end of the multimedia session, answered the survey questionnaire. The results of the study show that motivation to the class and the contents of education were statistically significant to the students'performance in the class. That implies, not only in the traditional instructor-teaching method but also in the multimedia class, that the contents of education itself and student's motivation to the class are most important to raise instructional results.

• Asia pacific journal of information systems
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• 제10권1호
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• pp.37-59
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• 2000

Recently, the rapid development of information technology has brought enormous changes in education. Consolidation of communications and multimedia technologies are enabling the new educational paradigm such as distance learning and virtual education. Furthermore, many studies in the education engineering field report that teaching using multimedia technologies more enhances students' performance than the traditional instructor-teaching method. However, little research regarding the education using multimedia has been done in the MIS filed. None of multimedia-related studies could be found in the top-ranked MIS journals published in Korea for the last five years, and only a few studies were found even worldwide. In this regard, the purpose of this study is to investigate which features of multimedia software are most important to enhance the teaching results of students, From the previous research, we found out the specific features of the educational multimedia software which are considered to affect the students' performance, and defined the research variables related to those educational software features, And, based on the constructivism and motivation theory of the education engineering field, a theoretical research model and research hypotheses were developed. Perceived usefulness of the class and a student's perceived interests in the class were used as surrogate variables to measure teaching performance. Total 277 students participated separately in one of the two multimedia classes which have continued for three weeks. One was C programming language class and the other was multimedia CD-title development class. Each student listened for the multimedia session of the class using multimedia software and, at the end of the multimedia session, answered the survey questionnaire, The results of the study show that motivation to the class and the contents of education were statistically significant to the students' performance in the class. That implies, not only in the traditional instructor-teaching method but also in the multimedia class, that the contents of education itself and student's motivation to the class are most important to raise instructional results.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.246-251
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• 1998

The basic requirement of a distributed multimedia system are intramedia synchronization which asks the strict delay and jitter for the check period of media buffer and the scaling duration with periodic continuous media such as audio and video media, and intermedia synchronization that needs the constraint for relative time relations among them when several media are presented in parallel. In this paper, a distributed multimedia synchronization algorithm based on the fuzzy logic is presented and the performance is evaluated through simulation. Intramedia synchronisation algorithm uses the media scaling techniques and intermedia synchronization algorithm uses variable service rates on the basis of fuzzy logic to solve the multimedia synchronization problem.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
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• pp.340-344
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• 2005

차세대 무선 망 시스템에서는 멀티미디어 서비스가 당연히 요구되며 그리고 경제적인 패킷 데이터 전송은 필수적이다. 이러한 점에서, OFDMA (WiBro) 시스템에서는 다양한 트래픽 클라스를 최적하게 제어할 수 있는 적응적 자원관리 방법이 요구된다. 본 논문은 과거의 서브 채널 상태정보를 기반으로 최근 서브 채널 상태를 예측하는 알고리즘을 개발하였고 이 방법을 이용하여 또한 다운링크의 멀티미디어 트래픽을 효과적으로 제어하는 스케줄링 알고리즘을 개발하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권6호
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• pp.1006-1022
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• 2010

In this paper, a cross-layer resource allocation mechanism is proposed for wireless multimedia service. In particular, a game theory based on quality of service (QoS) for multimedia users is introduced to deal with the fairness of network resource allocation in wireless networks. Moreover, the channel states of wireless users are additionally regarded under the cross-layer design in WiMAX environment. In details, the bargaining solution is adopted to discover the efficient and fair resource allocation strategy for multimedia service in considering QoS in the peak signal-to-noise ratio (PSNR) and the channel states in the carrier-to-interface ratio (CINR). The proposed mechanism is illustrated and evaluated by simulation results of transmitting video sequences in WiMAX environment.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.252-257
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• 1998

A method of multimedia information data acquisition based on fuzzy rules is proposed, where the multimedia means the five senses of a human being. Observed information is characterized by VAGOT(visual, acoustic, gustatory, olfactory and tactile) time series data and the goal is to extract an appropriate subset of the VAGOT data based on a given instruction. Fuzzy rules based on visual and acoustic information are used to identify the appropriate time interval on the fireworks multimedia information.