• 정보처리학회논문지C
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• 제14C권1호
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• pp.81-86
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• 2007

다양한 형태의 멀티미디어 서비스들은 서로 다른 QoS를 요구한다. 따라서, 서로 다른 멀티미디어 서비스를 효율적으로 지원하면서 동시에 우선순위가 높은 서비스의 QoS를 보장할 수 있는 효율적인 셀룰러/무선랜 오버레이 네트워크 관리기법에 대한 관심이 증가하고 있다. 본 논문에서는 효율적인 대역폭의 예약과 할당, 그리고 혼잡제어를 위한 통신 프로토콜을 통한 적응적 네트워크 관리기법을 제안하였다. 컴퓨터 시뮬레이션을 통하여 대역폭 관리를 위해 제안된 기존의 타 기법들과의 비곤 분석을 수행하여 제안된 방법이 다양한 네트워크 트래픽 상황에서 우수한 성능을 가지는 것을 확인할 수 있었다.

• 유통과학연구
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• 제18권8호
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• pp.103-112
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• 2020

Purpose: Business has been completely revolutionized by the Internet. This study seeks to determine the impact of e-business on activity extension and business performance. It aims to examine the actual stage of e-business, help others to apply the knowledge gained, and help in expanding new researches in this field. Research design, data and methodology: The data utilized in this study was obtained from survey. In total of 60 questionnaires accepted as valid out of 80 distributed, data was analyzed using the SPSS, and methods used were correlation and reliability analyses. Results: The study result shows that e-business has a significant positive impact on activity extension and the performance of business in Kosovo. The findings also revealed that there is a correlation between the various online marketing strategies and consumer satisfaction. The development of e-business for Kosovo is an important factor in participation in the world market, where there is a growing need for innovation and modernization of business. Conclusions: The study recommends that there should be raised awareness among business owners and managers as well as the general public. Moreover, there should be a proper application of marketing strategies to e-business.

• 한국문헌정보학회지
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• 제17권
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• pp.49-83
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• 1989

A Full text retrieval system is a natural language document retrieval system in which the full text of all documents in a collection is stored on a computer so that every word in every sentence of every document can be located by the machine. This kind of IR System is recently becoming rapidly available online in the field of legal, newspaper, journal and reference book indexing. Increased research interest has been in this field. In this paper, research on full text databases and retrieval systems are reviewed, directions for research in this field are speculated, questions in the field that need answering are considered, and variables affecting online full text retrieval and various role that variables play in a research study are described. Two obvious research questions in full text retrieval have been how full text retrieval performs and how to improve the retrieval performance of full text databases. Research to improve the retrieval performance has been incorporated with ranking or weighting algorithms based on word occurrences, combined menu-driven and query-driven systems, and improvement of computer architectures and record structure for databases. Recent increase in the number of full text databases with various sizes, forms and subject matters, and recent development in computer architecture artificial intelligence, and videodisc technology promise new direction of its research and scholarly growth. Studies on the interrelationship between every elements of the full text retrieval situation and the relationship between each elements and retrieval performance may give a professional view in theory and practice of full text retrieval.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.908-925
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• 2014

Induction Motor (IM) has several desirable features for high performance adjustablespeed operation. This paper presents the design of a robust controller for vector control induction motor drive performances improvement. Proposed predictive speed controller, which is aimed to guarantee the stability of the closed loop, is based on the Poisson-Laguerre (PL) models for the association vector control drive and the induction motor; without necessity of any mechanical parameter, and requires only two control parameters to ensure implicitly the integrator effect on the steady state error, load torque disturbances rejection and anti-windup effect. In order to improve robustness, insensitivity against external disturbances and preserve desired performance, adaptive control is added with the aim to ensure an online identification of controller parameters through an online PL models identification. The proposed control is compared with the conventional approach using PI controller. Simulation with MATLAB/SIMULINK software and experimental results for a 1kW induction motor using a dSPACE system with DS1104 controller board are carried out to show the improvement performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권6호
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• pp.2115-2130
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• 2022

With the development of over-the-top (OTT) services, the demand for content is increasing, and you can easily and conveniently acquire various content in the online environment. As a result, copyrighted content can be easily copied and distributed, resulting in serious copyright infringement. Some special forms of online service providers (OSP) use filtering-based technologies to protect copyrights, but illegal uploaders use methods that bypass traditional filters. Uploading with a title that bypasses the filter cannot use a similar search method to detect illegal content. In this paper, we propose a technique for profiling the Heavy Uploader by normalizing the bypassed content title and efficiently detecting illegal content. First, the word is extracted from the normalized title and converted into a bit-array to detect illegal works. This Bloom Filter method has a characteristic that there are false positives but no false negatives. The false positive rate has a trade-off relationship with processing performance. As the false positive rate increases, the processing performance increases, and when the false positive rate decreases, the processing performance increases. We increased the detection rate by directly comparing the word to the result of increasing the false positive rate of the Bloom Filter. The processing time was also as fast as when the false positive rate was increased. Afterwards, we create a function that includes information about overall piracy and identify clustering-based heavy uploaders. Analyze the behavior of heavy uploaders to find the first uploader and detect the source site.

• 한국경영과학회지
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• 제33권2호
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• pp.45-73
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• 2008

Quality has long been considered as an important factor in creating competitive advantage, and researches on quality have not been limited to off-line products but actively extended to e-services and information goods. However, given the nature of multi-dimensional aspect of quality, the systematic study on the quality of online service is still in its early stage. Especially, studies on the quality of ASP services have been rare in academic and professional journals despite the growth of ASP industry in its size and the rapid expansion in the range of application. In this paper we clarified the multi-dimensional quality aspects of the ASP service using a Garvin's framework (1984) which encompasses the service aspects of Products, and developed a measurement model for ASP service qualify. Then we empirically tested the effects of ASP service quality on user satisfaction and perceived firm performance using the data from 240 Korean small firms with less than 50 employees that had experienced the ASP service. Our results show that there are positive relationships among ASP service quality and personal performance, user satisfaction and perceived firm performance, and that product and service-related aspects of ASP service exert differential effects on performance measures so that the product-related aspects of the ASP service such as performance, features, reliability and conformance are considered to be more important in evaluating benefits from ASP services. Contrary to the approaches In literature where only the quality of online services is evaluated, our results emphasize the importance of differentiating Product and service-related aspects of ASP service and provide a basis for more comprehensive evaluation of ASP service quality.

• 한국IT서비스학회지
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• 제20권4호
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• pp.129-140
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• 2021

Recently, interest in AI tutors is rising as a way to bridge the educational gap in school settings. However, research confirming the effectiveness of AI tutors is lacking. The purpose of this study is to explore how effective learner characteristics and recommended item learning activities are in predicting learner's academic performance in an adaptive online learning environment. This study proposed the hypothesis that learner characteristics (prior knowledge, midterm evaluation) and recommended item learning activities (learning time, correct answer check, incorrect answer correction, satisfaction, correct answer rate) predict academic achievement. In order to verify the hypothesis, the data of 362 learners were analyzed by collecting data from the learning management system (LMS) from the perspective of learning analytics. For data analysis, regression analysis was performed using the regsubset function provided by the leaps package of the R program. The results of analyses showed that prior knowledge, midterm evaluation, correct answer confirmation, incorrect answer correction, and satisfaction had a positive effect on academic performance, but learning time had a negative effect on academic performance. On the other hand, the percentage of correct answers did not have a significant effect on academic performance. The results of this study suggest that recommended item learning activities, which mean behavioral indicators of interaction with AI tutors, are important in the learning process stage to increase academic performance in an adaptive online learning environment.

• 한국콘텐츠학회논문지
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• 제17권7호
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• pp.416-424
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• 2017

본 연구는 학습동기가 온라인 협력학습에서 상호작용에 미치는 영향을 분석하고자 한다. 이를 위해 수도권의 A대학에서 교직과목을 수강하는 79명의 대학생들을 대상으로 연구를 수행하였다. 학습동기는 MSLQ를 통해서 내적목적, 외적목적, 과제가치, 학습신념, 시험불안, 자기효능감, 성취목표지향성을 측정하였다. 다음으로 상호작용 수준을 측정하기 위해서 협력과제를 수행하였다. 협력과제를 위한 집단 편성은 4-5명으로 구성하였다. 전공과 관계없이 무선으로 편성하였다. 상호작용의 수준은 빈도와 양적 가치를 부여한 점수로 측정하였다. 수집된 자료는 다중회귀분석(단계적 선택방식)을 실시하여 학습동기가 상호작용의 수준에 미치는 영향을 검증하였다. 그 결과 자기효능감, 외적목표, 과제가치, 성취목표지향성의 수행접근성향과 숙달성향은 상호작용의 빈도와 점수에 정적인 영향이 있었다. 다음으로 시험불안과 성취목표지향성의 수행회피성향은 상호작용의 빈도와 점수에 부적인 영향이 있는 것으로 나타났다. 이와 같은 연구결과를 토대로 온라인 협력학습 상황에서 학습자의 지도에 대한 몇 가지 방안을 제안하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권11호
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• pp.2866-2879
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• 2012

Among the various security threats in online games, the use of game bots is the most serious problem. Previous studies on game bot detection have proposed many methods to find out discriminable behaviors of bots from humans based on the fact that a bot's playing pattern is different from that of a human. In this paper, we look at the chatting data that reflects gamers' communication patterns and propose a communication pattern analysis framework for online game bot detection. In massive multi-user online role playing games (MMORPGs), game bots use chatting message in a different way from normal users. We derive four features; a network feature, a descriptive feature, a diversity feature and a text feature. To measure the diversity of communication patterns, we propose lightly summarized indices, which are computationally inexpensive and intuitive. For text features, we derive lexical, syntactic and semantic features from chatting contents using text mining techniques. To build the learning model for game bot detection, we test and compare three classification models: the random forest, logistic regression and lazy learning. We apply the proposed framework to AION operated by NCsoft, a leading online game company in Korea. As a result of our experiments, we found that the random forest outperforms the logistic regression and lazy learning. The model that employs the entire feature sets gives the highest performance with a precision value of 0.893 and a recall value of 0.965.

• 디지털융복합연구
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• 제16권2호
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• pp.189-194
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• 2018

본 연구에서는 최근 정부주도로 학력이 아닌 직무능력 중심의 블라인드 채용문화를 확산시키고 있는 흐름을 반영하고, 기존 서류 중심의 온라인 채용 프로세스의 한계를 극복하기 위하여 원격 온라인 인력 채용을 위한 새로운 동영상 면접시스템 구조 설계안을 제안하고 이를 기반으로 시작품 개발 및 성능실험을 통해 효용성을 검증하고자 하였다. 제안하는 원격 동영상 면접시스템은 맞춤형 잡 매칭 및 원격 잡 코칭이 가능하도록 지능형 웹 기술을 융합하여 설계하였고, 이를 통해 구인기업의 채용비용 및 구직자의 기회비용이 절감될 수 있도록 구성하였다. 본 연구에서 도출된 설계 사양 및 시작품 개발 결과를 바탕으로 향후 공공 및 민간 채용시장에서 필요한 온라인 면접시스템 기술로서 상용화된다면 능력 중심 채용문화 정착을 위한 실용적인 온라인 채용 솔루션으로 활용이 기대될 수 있다.