• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.13-20
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• 1990

This paper describes an interframe image coding using motion compensated and classified vector quantizer (MC-CVQ). It is essential to carefully encode blocks with significant pels in motion compensated vector quantizers (MCVQ). In this respect, we propose a new CVQ algorithm which is appropriate to the coding of interframe prediction error after motion compensation. In order to encode an image efficiently at a low bit rate, we partition each block, which is the processing element in MC, into equally sized 4 vectors, and classify vectors into 15 classes according to the position of significant pels. Vectors in each class are then encoded by the vector quantizer with the codebook independently designed for the class. The computer simulation shows that the signal-to-noise ratio and the average bit rate of MC-CVQ are 35-37dB and 0.2-0.25bit/pel, respectively, for the videophone or video conference type image.

• The Journal of Korean Association of Computer Education
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• v.19 no.4
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• pp.45-58
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• 2016

This paper tried to analyze cases of one year team-based project of gifted students who spent two year programs in a math-IT integrated class as part of formative evaluation and extracted the factors associated with future enhancement for the program. The researcher as an advisory professor tried to guide the students as minimally as possible considering their levels of IT skills so that they could self-directedly perform the IT-fused project on a team basis. The data collection included documents, annual report, photos, video, artifacts and interview data with the students for the whole team project carried out between February and December, 2015. The overall pattern of the project activities has been stabilized in the middle of the course compared to the initial stages of brainstorming and design work even though the students revealed the differences of their programming skills and preferences toward the project theme. Their project outcomes were qualitatively analyzed according to the 9 steps of R&E model and has shown individual differences according to low, middle and high level. At the end, the analysis suggested several implications for further improvement of the mentorship program.

• Journal of Korean Elementary Science Education
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• v.29 no.3
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• pp.364-377
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• 2010

The purpose of this study was to analyze the within-group verbal interaction according to leader's personality in Thinking Science activities. For this study, 2 homogeneous small groups by cognitive level selected from one class of sixth grader. Each group was comprised of four students. Leaders of two groups selected from the results of NEO personality assessment and teacher's observation. One who got high scores in extraversion and agreeableness is named a sociable leader, the other who got low scores in extraversion and agreeableness is named a taciturn leader. Verbal interactions during small group activities were audio/video taped and students' interactions were classified into on-task and off-task. On-task included cognitive aspect and affective aspect. Interactions of cognitive aspect were divided into low and high level, also interactions of affective aspect were divided into positive and negative interaction. The results of this study showed that the verbal interactions in the sociable leader group were more activated than those in the taciturn leader group. Also, interaction level of the sociable leader group in cognitive aspect was higher than those of the taciturn leader group. In affective aspect, interaction pattern of the sociable leader group was similar to those of the taciturn leader group. The characteristics of leader's interaction are as follow. The rates of cognitive aspect in the sociable and the taciturn leaders' interactions were much higher than those of affective aspect. This tendency was especially remarkable in the taciturn leader's interactions. However, interaction level of the sociable leader in cognitive aspect was higher than those of the taciturn leader. In affective aspect, positive interaction rate of the sociable leader and the taciturn leader were higher than negative interaction rate.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.149-156
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• 2007

The purpose of this study was to compare the world class women's hurdlers with kinematic variables Lee Yeon-Kyoung's in the 100m hurdle. Among korea elite female hurdler, Lee Yeon-Kyoung was participated as a subject. Eight JVC video cameras(GR-HD1KR) were used to film the performance of Lee Yeon-Kyoung at a frame rate of 60fields/s. The real-life three-dimensional coordinate data of digitized body landmarks were smoothed using a fourth order Butterworth low pass recursive digital filter with an estimated optimum cutoff frequency of 7.4Hz. After analyzing and comparing Lee Yeon Kyung's kinematic variables with the world top class hurdlers in the woman's 100m hurdle run, the following conclusions were obtained. 1. Lee should be able to increase the speed with over 5.4m/s from start to first hurdle and then maintain the speed range from 8.33m/s to 8.67m/s until 10th hurdle. Lee should have to maintain the speed with 8.51m/s from 10th hurdle to finish line. 2. Lee has to reach her maximum running speed at 5th hurdle and then has to shorten running time with 0.5sec between hurdles. 3. Lee should be able to run around 2.5sec from start to frist hurdle and then maintain under 1.00sec following phases. Lee should be able to maintain under 1.10sec from 10th hurdle to finish line. 4. Lee needs to control a consistent takeoff and landing distance pattern, Lee needs to lower the height of the center of gravity of the body with 0.33m when she clears the hurdles.

• The KIPS Transactions:PartB
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• v.9B no.2
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• pp.173-180
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• 2002

The virtual cell loss rate was introduced for the training pattern of the neural network in the VOB(Virtual Output Buffer) model. The VOB model shows that the neural network can find the connection admission boundary without the real cell loss rate. But the VOB model tends to overestimate the cell loss rate, so the utilization of network is low. In this paper, we uses the reference curve of the cell loss rate, which contains the information about the cell loss rate at the connection admission boundary. We process the patterns of the virtual cell loss rate using the reference curve, We performed the simulation with two major ATM traffic classes. One is On-Off traffic class that has the traffic characteristic of LAN data and other is Auto-Regressive traffic class that has the traffic characteristic of a video image communication.

• Journal of Korean Elementary Science Education
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• v.24 no.2
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• pp.123-129
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• 2005

The purpose of this study was to investigate the interaction patterns between teachers and students appeared in sixth grade elementary science lessons. To this end, we set research questions as what are the types of SPS (Social Participation Structure) between teachers and students in the class. Eighteen elementary science lessons were observed. Data were collected by video recordings and observation method. The result showed that the types of SPS were classified into nine. 1) A teacher initiates the whole students into interaction with him. 2) The whole students keep silent or carry out specific activities under the teacher's direction. 3) A teacher initiates some students into interaction. 4) A teacher names specific students to read a text. 5) A teacher initiates the whole students into group interactions. 6) Students interact with each other irrespective of the teacher's intention. 7) Students initiate a teacher into interactions with them. 8) A teacher intervenes during the students' activities and this intervention, in turn, produces interactions between the teacher and the students. 9) A teacher directs the whole class to read a learning goal or a learning material. This study shows that SPS-1 and SPS-3 are the most frequently observed interaction patterns in the elementary science lessons.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8B
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• pp.707-715
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• 2003

In this paper, we propose a new MAC(Medium Access Control) protocol using Movable-boundary, which tries to guarantee Qos for multimedia traffic in the slotted CDMA system. In this scheme, the traffic scheduler assigns channel resource according to the packet priority per service class and adapts the Movable-boundary concept in which the minimum resource is assigned to each traffic class; the remaining resource if it is available can be assigned dynamically according to the temporal demand of other traffic classes. For performance analysis, we performed computer simulations to obtain throughput and packet loss rate and compared the results with Fixed-boundary system. We observed that the error rate of voice traffic could be maintained below a prescribed value while bursty traffic such as video source shares the same channel. In comparison with Fixed-boundary scheme, our protocol exhibits better throughput and packet loss rate performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.8
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• pp.1783-1791
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• 2010

Mobile WiMAX system provides broadband wireless access with a variety of services such as voice, video and data communications and providing QoS for each of these services become an important issue. In Mobile WiMAX system, it is important to allocate resources appropriately in order to support the efficient utilization of resources among various real-time and non real-time services. Although many packet scheduling schemes for real-time services in OFDMA system have been proposed, it need to be modified to apply to Mobile WiMAX system. Since Mobile WiMAX supports five types of service classes, QoS constraints of each class should be taken into consideration. In this paper, we propose an efficient packet scheduling scheme to support various services by considering the QoS constraints of each class.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.855-869
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• 1997

In this paper, we proposed two kids of dynamic priority control mechanisms controlling the cell service ratio in order to improve the QOS(Quality of Service). We also analyse theoretically the characteristics of cell loss probability and mean cell delay time by applying the proposed priority control mechanisms to ATM switch with output buffer. The proposed priority control mechanisms have the same principles of storing cells into buffer but the different principles of serving cells from buffer. The one is the control mechanism controlling the cell service ratio according to the relative cell occupancy ratio of buffer, the other is the control mechanism controlling the cell service ratio according to both the relative cell occupancy ratio of buffer and the average arrival rate. The two service classes of our concern are the delay sensitive class and the loss sensitive class. The analytical results show that the proposed control mechanisms are able to improve the QOS, the characteristics of cell loss probability and mean cell delay time, by selecting properly the relative cell occupancy ratio of buffer and the average arrival rate. conventional DLB algorithm does not support synchronous cells, but the proposed algorithm gives higher priority to synchronous cells. To reduce synchronous cell loss rate, the synchronous cell detector is used in the proposed algorithm. Synchronous cell detector detects synchronous cells, and passes them cells to the 2nd Leaky-Bucket. So it is similar to give higher priority to synchronous cells. In this paper, the proposed algorithm used audio/video traffic modeled by On/Off and Two-state MMPP, and simulated by SLAM II package. As simulation results, the proposed algorithm gets lower synchronous cell loss rate than the conventional DLB algorithms. The improved DLB algorithm for multimedia synchronization can be extended to any other cells which require higher priority.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.393-400
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• 2018

This study was to verify the effects of education in expression activity and various convergence education found in the class scene of one elementary school man teather to research of qualitative pattern and analyzes how it is expanded. This study were made through two class participation observation and six video analysis. In addition, we measured in-depth interviews of participants and students, a 10-week jump band training program, and applied a step-by-step physical activity program to enhance creative expressiveness. Based on the results of the study, the conclusions are as follows. First, It was found that the Jump-band training positively affects the students' speed, agility, and cardiopulmonary endurance. Second, It was found that the application of the step-by-step physical expression activity program had a positive effect on the students themselves. Third, It was found that it has an educational effect on the whole life of students beyond the curriculum and the field by attempting various fusion education. Based on this study, we propose the educational effects of the pre - curricular activities and the convergence lessons in elementary school during the follow - up research.