• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.881-892
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• 1999

In this paper we consider a polling system with two classes of stations; high priority and low priority. High priority stations are polled more frequently than low priority stations. We derive an exact and explicit formula for computing the mean waiting times for a message when the arrival processes are batch Poisson. In general the formula requires to solve two sets of simultaneous equations By specializing them to the case of two priority classes we greatly reduce the number equations and provide a simple formula for mean waiting times. We apply the results to a data communication processing system and show that the overall mean waiting time can be reduced by using priority polling.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.778-804
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• 2017

Software today has become an inseparable part of our life. In order to achieve the ever demanding needs of customers, it has to rapidly evolve and include a number of changes. In this paper, our aim is to study the relationship of object oriented metrics with change proneness attribute of a class. Prediction models based on this study can help us in identifying change prone classes of a software. We can then focus our efforts on these change prone classes during testing to yield a better quality software. Previously, researchers have used statistical methods for predicting change prone classes. But machine learning methods are rarely used for identification of change prone classes. In our study, we evaluate and compare the performances of ten machine learning methods with the statistical method. This evaluation is based on two open source software systems developed in Java language. We also validated the developed prediction models using other software data set in the same domain (3D modelling). The performance of the predicted models was evaluated using receiver operating characteristic analysis. The results indicate that the machine learning methods are at par with the statistical method for prediction of change prone classes. Another analysis showed that the models constructed for a software can also be used to predict change prone nature of classes of another software in the same domain. This study would help developers in performing effective regression testing at low cost and effort. It will also help the developers to design an effective model that results in less change prone classes, hence better maintenance.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.640-648
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• 2002

The purposes of this study is to examine the effects of cooperative teaming through student team-achievement division (STAD) model on high school students’ leaming achievements and scientific attitudes in the field of astronomy. It is another aim to compare effects of cooperative learning based on improvement scores with traditional teaching method done only by teachers in astronomy field. This study was conducted on two tenth grade classes in a boy’s high school in Incheon. Students had four classes a week in cooperative learning way for four weeks. During cooperative learning classes, formative evaluation was given to students every week oil Stars and Exploring the Solar System. The results show that these two approaches have great different effects on students’ astronomical knowledge and that students adopt more positive scientific attitude toward cooperative learning classes than traditional ones. In conclusion, the cooperative learning is more effective and positive than traditional one in learning astronomical knowledge and in students scientific attitude for science classes.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.267-270
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• 1999

Use of coherence data from operational satellite based SAR sensors has been experimented both on C and L band to identify landcover in tropics. While coherence data proved useful to improve accuracy in landcover identification, such data are not readily available. On the other hand, integrated use of backcatter data by multiple satellites is readily feasible. The very question to be asked is whether integration of backscatter data on multiple bands (e.g. C and L band) is either inferior or superior to use of coherence data. We therefore still do not have a solid clue to answer to the very question. The aim of this study is to evaluate the performance of "integrated use" of backscatter data on C and L band (by ERS and JERS respectively) to identify landcover, vis-a-vis the same by combination of backscatter and coherence data by single satellite. The study was carried out for an area in the southern part of the Sumatra Island, Indonesia. The area has been intensively converted from natural forest into plantation. Five categories of landcover exist in this study area. By ERS-1, only 2 or 3 classes may be identified with the backscatter data alone, while adding the coherence data could delineate 4 classes. By JERS-1, only 3 to 4 classes may be identified with the backscatter data alone, while 4 classes could be clearly delineated by adding the coherence data. By integrating backscatter data on two bands, 4 to 5 classes may be identified. It represents the best results among cases examined. The outcome of the study suggests that integrated use of backscatter data on two bands by ERS and JERS is as powerful as use of backscatter and coherence data on single band by one of these satellite.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.23 no.3
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• pp.292-299
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• 2016

Purpose: The purpose of this study was to provide a basis for improvement and enhancement of nursing education by investigating learning outcomes that apply to fundamentals of nursing and teaching methods used in classes. Methods: Data were collected from 111 professors of fundamentals of nursing who responded to the self-report questionnaire. Data were analyzed using chi-square test. Results: For learning outcomes in fundamentals of nursing the most frequent number of outcomes was two (35.2%), or three (32.4%). For learning outcomes in fundamentals of nursing practicum, the most frequent number of outcomes was two (32.4%), or three (31.6%). In fundamental nursing classes, teaching methods used most frequently were lectures (98.2%) and videos (60.4%), and in practice classes, demonstration (98.2) and open laboratory (90.9%). Constructivist teaching methods that were utilized in fundamental nursing were team-based learning (19.8%) and case-based learning (19.8%), and for practice classes, objective structured clinical examination (29.7%). In the cross analysis, 28.8% of the nursing professor used the constructivist teaching methods in fundamental nursing and in practice classes. Conclusion: There is a need to continue to improve teaching methods for new nurse-educators and professors and to discuss learning outcomes of fundamental nursing.

• Journal of Korean Elementary Science Education
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• v.17 no.2
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• pp.113-121
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• 1998

This study was performed to examine the effects of daily commodities on student's scientific knowledges, inquiring abilities and attitude toward science in elementary school science classes. Daily commodities were collected and sorted properly so as to be readily utilized as experimental instruments in science classes. 164 students of elementary school 5th grade in Taejon City were selected for the study and they were evenly divided into two different groups, one for experiment and the other for comparation respectively. In every science classes throughout the school semester, the experimental group was supplied with daily commodities in addition to conventional instruments while the controlled group for comparation was supplied only with conventional instruments. Student's responses to the questionnaire were treated by statistical analysis and for that purpose the computer programme of SPSS WIN(6.0) was employed. The results of the study are as follows; 1. There is no expressive disparity appeared in the increments of scientific knowledge between experimental and controlled (comparing) groups. 2. The disparity of increments in inquiring ability between experimental and controlled groups is fairly expressive (P<0.05). The experimental group with daily commodities in science classes attained 5% more in increment of inquiring ability than the controlled group. 3. The disparity of the changes in student's attitudes toward science between two groups is remarkable (P<0.001). Student's attitude toward science was much more improved in experimental group than controlled group. The difference in improvement rate between two groups is 8%. The facts mentioned above make it evident that in elementary school science course daily commodities are very effective to enhance student's positiveness as far as both inquiring ability and attitude toward science are concerned. In this respect, a lot of efforts are expected to be made in searching and supplying further the proper daily commodities for elementary science courses. In addition, it is also called for that the examples of replacing conventional instruments with daily commodities will be introduced in future editions of elementary school science book and its guide book if possible.

• The KIPS Transactions:PartB
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• v.13B no.5 s.108
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• pp.547-552
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• 2006

There have been various cohesion measurements studied considering reference relation among attributes and methods in a class. Generally, these cohesion measurement are camed out in one class. If the range of reference relation considered are extended from one class to two classes, we could find out the reference relation between two classes. Tn this paper, we proposed a neural network to determine the method location. Neural network is effective to predict output value from input data not to be included in training and generalize after training input and output pattern repeatedly. Learning vector is generated with 30-dimensional input vector and one target binary values of method location in a constraint that there are two classes which have less than or equal to 5 attributes and methods The result of the proposed neural network is about 95% in cross-validation and 88% in testing.

• Korean Journal of Childcare and Education
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• v.16 no.1
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• pp.51-74
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• 2020

Objective: This study tried to find out if a teacher education program that supports professionalism for beginning child care teachers in toddler classes is effective in professionalism, self-respect, and efficacy in teaching. Methods: The study subjects were 40 beginning child care teachers in toddler classes teaching in day care centers in Seoul, Incheon, and Gwangmyeong Gyeonggi-do. They were divided into an experimental group (20 teachers) and a comparative group (20 teachers). The collected data were applied to the SPSS 22.0 program. To find homogeneity of the two groups, a t-test was conducted. To analyze an intergroup difference, ANCOVA was conducted in the way of setting a pre-test score as a covariate. Results: The experimental group which participated in the program showed more positive effects than the comparative group in terms of professionalism, self-respect, and efficacy in teaching. Conclusion/Implications: Based on the results of this study, the program is expected to be meaningful in the field of early childhood education, and to lay the foundation for beginning child care teachers in toddler classes to become experts in their field.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.59-66
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• 2003

We propose the novel optical burst switching scheme to guarantee a minimum bandwidth for multiple classes. To date, QoS studies on OBS network are capable of differentiating two classes, but have difficulties in providing a minimum bandwidth lot several classes because of lower classes' collision with the highest class bursts in the networks. To solve that problem, in our proposed scheme we assign time zones in a data channel for each class periodically, making one burst have top priority at least its zone. Also, the new burst assembling algorithm, as well as the way of managing data channel, is necessarily proposed to coordinate with the proposed OBS scheme. Through the evaluation, we show that the worst-case end-to-end delay is small enough and the received bandwidth of the lower classes is still assured regardless of the traffic load of the highest class.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.277-284
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• 2012

The purpose of this study was to find out the changes in beginners' batting movements after taking undergraduate baseball lectures, by comparing and analyzing the speed of bat, the angle of body and its segments, the angular velocity and so on. For this purpose, the author picked up five undergraduates who had not taken baseball lectures, and conducted three-dimension computerized tomography twice on them, that is, before and after taking baseball classes, with eight infrared cameras and two force platforms. The conclusions are, first, the time required for swing was shortened after taking the classes. Second, the maximum velocity of the bat-end was increased. Third, at the time of impact, while the rotation angles of the pelvis and the tip of left foot were increased, the left elbow had more flexion after the classes. Fourth, the size of ground reaction force was increased at the point of swing where the ground reaction force of left foot became maximized. As we can infer from these conclusions, beginners' hitting movements before taking baseball classes tended to swing only with the arms, without waist rotation and weight shift of the lower body, but after the classes, their movements were proved to be corrected into the swing using the lower body. For the future studies, the author expects a research in a close to real environment by using pitching machine.