• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.629-642
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• 1996

ATM switch handles the traffic for a wide range of appliations with different QOS(Quality-of-Service) requirements. In ATM switch, the priority control mechanism is needed to improve effectively the required QOS requirements. In this paper, we propose a priority control mechanism using the cell transfer ratio type and discard threshold in order to archive the cell loss probability requirement and the delay requirement of each service class. The service classes of our concern are the service class with high time priority(class 1) and the service class with high loss priority control mechanism, cells for two kind of service classes are stored and processed within one buffer. In case cells are stored in the buffer, cells for class 2 are allocated in the stored and processed within one buffer. In case cells are stored in the buffer, cells for class 2 are allocated in the shole range of the buffer and cells for class 1 are allocated up to discard threshold of the buffer. In case cells in the buffer are transmitted, one cell for class 1 is transmitted whenever the maximum K cells for class 2 are transmitted consecutively. We analyze the time delay and the loss probability for each class of traffic using Markov chain. The results show that the characteristics of the mean cell delay about cells for class 1 becomes better and that of the cell loss probability about cells for class 2 becomes better by selecting properly discard threshold of the buffer and the cell transfer ratio according to the condition of input traffic.

• Journal of Arbitration Studies
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• v.27 no.1
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• pp.3-35
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• 2017

For recent years, several disputes between Korean consumers and multinational companies have arisen. Since the disputes were big and material that children's safety was at issue, a question started if Korean law properly has protected consumers' rights against multinational companies. While the Korean legal society tried to legislate punitive compensation with this concern, the U.S. Supreme Court reached an interesting case law regarding consumer contracts. A recent trend on consumer contracts in the United States shows that general terms have arbitration clause with class action waiver. As much as international arbitration has worked as the most effective resolution in international commercial disputes, the concept is still foreign and the experts are not approachable to lay individual consumers. However, class action in arbitration can hugely help for lay individual consumers to bring a case before arbitration tribunal. California courts consistently showed the analysis that the practical impact of prohibiting class action in arbitration clause is to ban lay individual consumers from fighting for their rights. However, the Supreme Court held that the arbitration clause shall be enforced as parties agree even if consumers practically cannot fight for their rights in the end. Even though consumer contracts are a typical example of lack of parity and of adhesive contract, the Supreme Court still applies liberalism that parties are equal in power and free to agree. This case law has a crucial implication since Korean consumers buy goods and services from the U.S. and other countries in everyday life. Accordingly, they are deemed to agree on the dispute resolution clauses, which might violate their constitutional right to bring their cases before the adjudication tribunal. This issue could be more important than adopting punitive compensation because consumers' rights are not necessarily governed by Korean law but by the governing law of the general terms and conditions chosen and written by the multinational companies. Thus this paper studies and analyzes the practical reality of international arbitration and influence of arbitration clause with class action waiver with the U.S. Supreme Court and California case laws.

• The Journal of Korean Medicine
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• v.22 no.4
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• pp.69-78
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• 2001

Objectives : It is known that cigarette smoking is associated with increased risk of both thrombotic and hemorrhagic stroke. However, in Korea, especially in the academic world of Korean Medicine, there is a lack of study about the relation between cigarette smoking and stroke. We carried out a case-control study to clarify the relation between cigarette smoking and stroke. Method : We interviewed 441 stroke patients (236 men, 205 women) as a case group and 432 non-stroke patients (208 men, 224 women) as a control group. We investigated the smoking pattern of all patients and stroke-subtype of the case group. Smoking pattern is classed into two (Class I), four (Class II) and five groups (Class III). Class I consists of current non-smokers and current smokers. Class II consists of non-smokers, former smokers, current light smokers and current heavy smokers. Class III consists of never smoked, secondhand smokers, former smokers, Current light smokers and current heavy smokers. Stroke-subtype consists of cerebral infarction and cerebral hemorrhage. Results : The percentage of current smokers of case group is higher significantly than that of control group. The number of cigarettes smoked per day is associated positively with the risk of stroke. According to our study, generally cigarette smoking is related with ischemic stroke. The percentage of secondhand smokers of the case group is lower than that of the control group. According to our study, characteristically secondhand smoking is associated with hemorrhagic stroke. Conclusions : From the above results we found that cigarette smoking is an important risk factor of stroke - especially cerebral infarction - and the number of cigarettes smoked per day is associated positively with the risk of stroke. Characteristically according to our study, secondhand smoking is associated with hemorrhagic stroke. Overall we conclude that cigarette smoking may be an important preventable factor for stroke.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.9
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• pp.563-571
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• 2018

The purpose of this study is to explore the direction of multicultural mentoring class activities in order to promote the professional growth and critical reflection of student mentors who are undergraduate students from a variety of major. For this purpose, the contents and phenomena of the multicultural mentoring of the mentor - mentee were reported as activity texts, and then seven directions of textuality were applied to explore the direction of multicultural mentoring class activities. As a result, coherence refers to the relationship between the mentor and the mentee for continuing the activities of multicultural mentoring, and cohesiveness refers to the relationship between the mentor and the mentee. It was called the achievement of identity. Intention means that the mentor has an intention or goal for the class before the mentoring activity, and tolerance means that the text produced by the mentor in the multicultural mentoring process is accepted by the mentee. Intentional means that the mentor has intention or goal for the class before the mentoring class activity, and tolerance means having the text as the class activity text when the mentor's text is accepted by the multicultural mentoring class activity process. In the case of informativeness, the information produced by the mentor is less informative when the mentee is predictable and less informative when the predictor is low. In the case of contextuality, contextuality of class activities can be changed according to the physical text situation and the mentee situation in class activity. In case of multicultural mentoring class activity, except for case where mentor creates new class activity text, it is related to the production of class activity texts through mentor learning experiences, peer friends' advice, and education.

• Journal of Engineering Education Research
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• v.16 no.4
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• pp.15-20
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• 2013

The result of the English test for freshmen showed wide difference in the ability of students, which means the graded class is strongly required. This paper describes the case study about the graded English class that was carried out for the freshman. Every freshman must take an English placement test from problems bank and were classified according to the result of the test. In order to resolve the dissatisfaction of the high level students, the statutes of my university for credit were modified. In order to analyze the effect of the graded class, evaluation test using similar problems was carried out at the end of the semester. The effect of the graded class was analyzed by using the paired samples t-test method and there was a meaningful performance improvement at the average score. Additional improvements in the method of classification and credit granted were made by analyzing the results of the evaluation test and survey.

• Honam Mathematical Journal
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• v.26 no.4
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• pp.509-532
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• 2004

Lower dimensional cases of Einstein's connection were already investigated by many authors for n = 2, 3, 4, 5, 6, 7. This paper is the first part of the following series of two papers, in which we obtain a surveyable tensorial representation of 8-dimensional Einstein's connection in terms of the unified field tensor, with main emphasis on the derivation of powerful and useful recurrence relations which hold in 8-dimensional Einstein's unified field theory(i.e., 8-g-UFT): I. The recurrence relations in 8-g-UFT II. The Einstein's connection in 8-g-UFT All considerations in these papers are restricted to the second class only, since the case of the first class are done in [1], [2] and the case of the third class, the simplest case, was already studied by many authors.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.76.1-76.1
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• 2014

We investigate the solar flare and CME occurrence rate and probability depending on sunspot class and its area change. These CMEs are front-side, partial and full halo CMEs associated with X-ray flares. For this we use the Solar Region Summary(SRS) from NOAA, NGDC flare catalog, and SOHO/LASCO CME catalog for 16 years (from January 1996 to December 2011). We classify each sunspot class into two sub-groups: "Large" and "Small". In addition, for each class, we classify it into three sub-groups according to sunspot class area change: "Decrease", "Steady", and "Increase". In terms of sunspot class area, the solar flare and CME occurrence probabilities noticeably increase at compact and large sunspot groups (e.g., 'Fkc'). In terms of sunspot area change, solar flare and CME occurrence probabilities for the "Increase" sub-groups are noticeably higher than those for the other sub-groups. For example, in case of the (M+X)-class flares of 'Dkc' class, the flare occurrence probability of the "Increase" sub-group is three times higher than that of the "Steady" sub-group. In case of the 'Eai' class, the CME occurrence probability of the "Increase" sub-groups is five time higher than that of the "Steady" sub-group. Our results demonstrate statistically that magnetic flux and its emergence enhance solar flare and CME occurrence, especially for compact and large sunspot groups.

• Journal of the Korean Professional Engineers Association
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• v.10 no.2
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• pp.27-34
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• 1977

The principle, performance and applications of the unique Class-D power amplifier, having power conversion efficiency of 100% in ideal case, have been described.

• Journal of the Korea Society of Computer and Information
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• v.21 no.7
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• pp.93-100
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• 2016

This paper shows what kind of influence the learning motivation factors have on the effectiveness of Flipped Learning Model through the case of operating a JAVA programming subject. The Flipped Learning Approach consisting of Before Class, Before or At Start of Class, and In Class provides the students with learning motivation as well as satisfies Keller's ARCS(Attention, Relevance, Confidence, Satisfaction) to keep them studying steadily. This research conducts the operation of Flipped Learning and gets Exploratory Factor Analysis and Reliability Analysis from the result of the course experience questionnaire at the end of the class. Given this survey result, Flipped Learning approach improves the learners' satisfaction in class and the effectiveness in the fields of understanding learning context more than does the previous lecture-based learning approach by pacing learning procedure and conducting self-directed learning.

• Journal of Engineering Education Research
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• v.23 no.5
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• pp.16-25
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• 2020

This article aims to analyze the experience of designing and operating a class model linking undergraduate and graduate students in engineering education and suggest its development direction. To achieve these objectives, the undergraduate-graduate linked class model was applied to community problem-solving education and a case was analyzed. It also specifically presented the process of how we design the class model and what the actual operational performances and improvements are. This study found that undergraduate and graduate students could build integrated and horizontal cooperative relationships in their classes through undergraduate-graduate linked education and, particularly, graduate students could gain meaningful educational experiences. However, it was difficult to obtain tangible performances through the team activities of these students within a semester. In order for engineering colleges to operate undergraduate-graduate linked education, it would be necessary to provide a longer and more systematic educational environment and better curriculum. The study tried to seek specific tasks and ways to improve them.