• 지식경영연구
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• 제9권4호
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• pp.17-33
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• 2008

This study proposes University 2.0 as a model case of open, flexible, and distributed learning environment for higher education based on theoretical foundations and perspectives. As web 2.0 technologies emerge into the field of education, ways of generating and disseminating information and knowledge have been drastically changed. Professors are no longer the only source of knowledge. Students using internet often become prosumers of knowledge who search and access information through the web as well as publish their own knowledge using the web. A concept and framework of University 2.0 is introduced for implementing the new interactive learning paradigm with an open, flexible and distributed learning environment for higher education. University 2.0 incorporates online and offline learning environments with various educational media. Furthermore, it employs various learning strategies and integrates formal and informal learning through learning communities. Both instructors and students in University 2.0 environment are expected to be active knowledge generators as well as creative designers of their own learning and teaching.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권1호
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• pp.117-135
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• 2016

Performance enhancement is one of the most important issues in high performance distributed computing systems. In such computing systems, online users submit their jobs anytime and anywhere to a set of dynamic resources. Jobs arrival and processes execution times are stochastic. The performance of a distributed computing system can be improved by using an effective load balancing strategy to redistribute the user tasks among computing resources for efficient utilization. This paper presents a multi-class load balancing strategy that balances different classes of user tasks on multiple heterogeneous computing nodes to minimize the per-class mean response time. For a wide range of system parameters, the performance of the proposed multi-class load balancing strategy is compared with that of the random distribution load balancing, and uniform distribution load balancing strategies using simulation. The results show that, the proposed strategy outperforms the other two studied strategies in terms of average task response time, and average computing nodes utilization.

• 한국시뮬레이션학회논문지
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• 제13권4호
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• pp.43-53
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• 2004

The distributed OCSP (Online Certificate Status Protocol), composed of multiple responders, is a model that enhances the utilization of each responder and reduces the response time. In a multi-user distributed environment, load balancing mechanism must be developed for the improvement of the performance of the whole system. Conservative load balancing algorithms often ignore the communication cost of gathering the information of responders. As the number of request is increased, however, fail to consider the communication cost may cause serious problems since the communication time is too large to disregard. We propose an adaptive load balancing algorithm and evaluate the effectiveness by performing modeling and simulation. The principal advantage of new algorithm is in their simplicity: there is no need to maintain and process system state information. We evaluated the quality of load balancing achieved by the new algorithm by comparing the queue size of responders and analyzing the utilization of these responders. The simulation results show how efficiently load balancing is done with the new algorithm.

• 대한치과기공학회지
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• 제43권4호
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• pp.186-193
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• 2021

Purpose: The purpose of the study was to determine the general characteristics of students in dental technology departments; the correlations among their immersion in learning, class satisfaction, and academic achievement; factors influencing online learning experience; ways to improve students' class satisfaction; and basic data for designing effective online courses. Methods: A total of 300 questionnaires were produced and distributed to dental technology students from September 29 through October 8, 2020. The outcome was analyzed using IBM SPSS Statistics ver. 25.0. A significance level of α=0.05 was used for reliable verification. Results: Immersion in learning, class satisfaction, and academic achievement were relatively high among students who studied on a regular basis, and class satisfaction and academic achievement were relatively high among students who studied with almost no interruption. Concerning the correlations between academic achievement, immersion in learning, and class satisfaction in online learning, the correlation between academic achievement and class satisfaction was the highest at r=0.862. Class satisfaction was the largest factor that influenced academic achievement, and the higher students' immersion in learning and class satisfaction were, the higher their academic achievement was. Conclusion: The research is a case study that investigated the general characteristics of dental technology department students and the correlations among their immersion in learning, class satisfaction, and academic achievement. The study outcome could be used in determining factors that influence online learning and designing effective online courses that improve learner satisfaction.

• Journal of Communications and Networks
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• 제13권3호
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• pp.277-285
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• 2011

Real-time multimedia streaming over the Internet is rapidly increasing with the popularity of user-created contents, Web 2.0 trends, and P2P (peer-to-peer) delivery support. While many homes today are broadband-enabled, the quality of experience (QoE) of a user is still limited due to frequent interruption of media playout. The vulnerability of TCP (transmission control protocol), the popular transport-layer protocol for streaming in practice, to the packet losses, retransmissions, and timeouts makes it hard to deliver a timely and persistent flow of packets for online multimedia contents. This paper presents TCP-real-time online multimedia environment (ROME), a novel transport-layer framework that allows the establishment and coordination of multiple many-to-one TCP connections. Between one client with multiple home addresses and multiple co-located or distributed servers, TCP-ROME increases the total throughput by aggregating the resources of multiple TCP connections. It also overcomes the bandwidth fluctuations of network bottlenecks by dynamically coordinating the streams of contents from multiple servers and by adapting the streaming rate of all connections to match the bandwidth requirement of the target video.

• ETRI Journal
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• 제33권2호
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• pp.219-229
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• 2011

In this paper, we propose a transformation scheme used to analyze online gaming traffic properties and develop a traffic model. We analyze the packet size and the inter departure time distributions of a popular first-person shooter game (Left 4 Dead) and a massively multiplayer online role-playing game (World of Warcraft) in order to compare them to the existing scheme. Recent online gaming traffic is erratically distributed, so it is very difficult to analyze. Therefore, our research focuses on a transformation scheme to obtain new smooth patterns from a messy dataset. It extracts relatively heavy-weighted density data and then transforms them into a corresponding dataset domain to obtain a simplified graph. We compare the analytical model histogram, the chi-square statistic, and the quantile-quantile plot of the proposed scheme to an existing scheme. The results show that the proposed scheme demonstrates a good fit in all parts. The chi-square statistic of our scheme for the Left 4 Dead packet size distribution is less than one ninth of the existing one when dealing with erratic traffic.

• International Journal of Advanced Culture Technology
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• 제9권4호
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• pp.9-17
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• 2021

This is a descriptive investigative study which attempts to confirm the mediating effect of learning motivation in the relationship between self-directed learning, learning commitment, and learning persistence intention of university students in an online learning environment. The questionnaires were randomly distributed online and the agreed questionnaires were retrieved, with a total of 338 copies used for analysis. The following is the summary of the findings. First, there were significant differences in learning persistence intention according to general characteristics depending on age, major, part-time job, and academic level. Second, the results showed a positive correlation between self-directed learning, learning commitment, learning motivation, and learning persistence intentions of the subjects were statistically significant. Third, after checking the mediating effect of learning motivation in relation to self-directed learning, learning commitment and learning motivation, the learning motivation has a partial mediating effect on learning and 23% explanatory power, and the learning commitment was found to have a complete mediating effect on the impact of learning motivation on learning intentions with 21% explanatory power. Based on these results, it is necessary to provide a more diverse educational environment, such as operating a motivation semester program that can improve learning motivations along with learning commitment, and the use of a variety of contents that can focus the learner's interest or attention.

• Journal of the Korean Data and Information Science Society
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• 제24권5호
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• pp.989-998
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• 2013

최근 산/학계에서 주목받고 있는 빅 데이터는 정의상 한꺼번에 자료를 메모리에 올려 분석할 수 없기 때문에 기존의 데이터마이닝 시대에 개발된 일괄처리 (batch processing) 방식의 알고리즘을 적용할 수 없게 된다. 따라서 가장 시급히 해결해야 하는 문제는 기존의 여러 가지 기계학습방법을 빅 데이터에 적용할 수 있도록 분산처리 (distributed processing)를 수행하는 적절한 알고리즘을 개발하는 것이라 볼 수 있다. 본 논문에서는 분류문제에서 각광받는 지지벡터기계 (support vector machines)의 여러 알고리즘을 살펴보고자 한다. 특히 빅 데이터 분류문제에 유용할 것으로 예상되는 온라인 타입 알고리즘과 병렬처리 알고리즘에 대하여 소개하고, 이러한 알고리즘들의 성능 및 장단점을 선형분류에 대한 모의실험을 통해서 살펴본다.

• 산경연구논집
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• 제11권2호
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• pp.17-23
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• 2020

Purpose: The purpose of this study is to understand the effect of the unique product recommendation system on customer satisfaction. Research design, data and methodology: The survey method used the self-recording way in which the respondents selected for the study and distributed 300 questionnaires, and with due personal care, researchers collected all the distributed questionnaires. Results: The result implies that the characteristics of the product recommendation system should be more secure and developed. Conclusions: The aspects of the product recommendation system were selected as factors of price fairness, accuracy, and quality through previous studies, and the empirical analysis of the effect of the characteristics of the product recommendation system on customer satisfaction was summarized as follows. Among the attributes of the product recommendation system, the attributes of price fairness, accuracy, and quality affect customer satisfaction. Among them, the beta value of quality was the highest, and the effect of quality was the largest among the three factors. Based on the results of the study, the implications for the characteristics of the product recommendation system are summarized as follows. The aspects of the product recommendation system have a positive effect on customer satisfaction, so it is necessary to fill the needs of consumers based on the survey focused on quality

• 정보보호학회논문지
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• 제28권4호
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• pp.879-888
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• 2018

최근 국내외 핀테크의 발전과 더불어 모바일 결제 시장에서 생체 인식 기술을 이용한 FIDO(Fast IDentity Online)가 기존의 패스워드 방식을 대체하며 빠르게 성장하고 있다. 이러한 FIDO 인증은 민감한 생체정보를 처리해야 하므로 반드시 높은 보안성이 요구되는 신뢰할 수 있는 환경에서 처리가 이루어져야 한다. 그러나 이러한 신뢰할 수 있는 환경은 스마트폰의 특정 하드웨어에서 지원하므로 제조사에 의존적일 수밖에 없다. 이에 본 논문에서는 모바일 환경에서 특정 하드웨어가 탑재되지 않아도 보편적으로 안전하게 사용할 수 있는 컴플라이언스 기반의 생체정보의 분산 관리를 이용한 서버 기반의 인증 모델을 제안하고자 한다.