• The Mathematical Education
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• v.46 no.1 s.116
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• pp.53-67
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• 2007

During the recent years at a middle level Engineering School located at the local areas in Korea, more than 20 percent of freshmen had failed at their first College Mathematics. In consequence, many of them had hard time to survive at their major curriculums. The purpose of this study is to look for the main reasons of their failure and suggest an alternation of the present curriculum. Using the responses to the questionnaires and placement test scores, we studied the characteristics of the students' Mathematical abilities and analyzed how they were related to their grades of the First College Mathematics at the end of the first semester. The mathematical ability of the students at the middle level Engineering School turned out to range from bottom to top even though most of them revealed their interests towards Mathematics. The students with low scores at the placement test were more likely to fail at their first College Mathematics. Thus we suggest that the school should open a new preparation course ahead of the First College Mathematics for those who achieve low scores at the placement test and also professors should write proper books and develop ways of teaching.

• Physical Therapy Rehabilitation Science
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• v.4 no.1
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• pp.49-54
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• 2015

Objective: Cervical stabilization exercises are frequently to improve strength and endurance of cervical muscles. The purpose of this study was to identify changes in head repositioning accuracy (HRA) and neck proprioception through cervical stabilization exercises in healthy adults. Design: One group pretest-posttest design. Methods: Thirteen participants with no previous history of neck pain or injury to the cervical spine were recruited. HRA was measured by equipment including laser pointer, helmet, eye patch and marking pens. The distance between the spot where the beam had stopped and the center of the graph paper was measured three times with the averaged value used as the head repositioning accuracy. Neck proprioception was measured by a cervical range of motion device (CROM). Subjects wore the CROM tester and were to look straight ahead while bending his/her neck. Subjects were instructed to perform extension, lateral flexion and rotation, and the values were then measured and recorded. The measurements were performed pre-intervention, and after cervical stabilization exercise. Results: There was no significant difference on HRA after intervention. In addition, there was no significant difference on neck proprioception compared with pre-intervention. Conclusions: The present study did not identify any effect on HRA and neck proprioception of cervical stabilization exercise. Further investigations are required to elucidate this in old aged participants and patients with neck pain.

• Journal of the Korean Home Economics Association
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• v.46 no.8
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• pp.37-54
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• 2008

We developed an education program for parents of adolescents titled Parents from Mars getting through to children from Venus. The program consists of five two-hour sessions each with a different theme; (1) parent-child communication, (2) study activities, (3) computer use, (4) children's daily expenses, and (5) children's daily-life plan. The program was test-run with seventeen participants, which included mothers of 4th grade(elementary school) to 9th grade (middle school) children. Based on data analysis, we found that average satisfaction level was 3.80 out of 5.00 and average goal accomplishment level was 3.91 out of 5.00. Most of the participants agreed that the program helped them to understand their children's problems, to look back on themselves as parents, to plan ahead, and eventually to improve their relationship with their children. However, it was also pointed out that the program needed to put more emphasis on practical lessons rather than theoretical lectures. For example, the need for more audiovisual materials, and more practical training during each session was highlighted by participants.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.869-877
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• 2007

This paper proposes a realtime scheduling method using local search algorithm for non-crossable yard cranes in automated container terminal. To take into consideration the dynamic property of yard crane operation and satisfy the real time constraint, the proposed method repeatedly builds crane schedule for the jobs in a fixed length look-ahead horizon whenever a new job is requested In addition, the proposed method enables the co-operation between yard cranes through prior re-handling and re-positioning in order to resolve the workload imbalance problem between the two cranes, which is one of the primary causes that lower the performance of yard cranes. Simulation-based experiments have shown that the proposed method outperforms the heuristic based methods, and the cooperation scheme contributes a lot to the performance improvement.

• The Southeast Asian review
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• v.24 no.2
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• pp.35-79
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• 2014

This study examines the measures for the activation and the growth of intra-regional trade in Southeast Asia taking a look at the four dimensions of tariff rates, non-tariff barriers, trade facilitations, and trade infrastructures. Utilizing a gravity model, we performed empirical analysis and discussed the policy implications with the priorities to implement. To expand the intra-regional trade in Southeast Asia it would be necessary to enhance the level of trade facilitations and provide trade infrastructures, such as ports and airports as well as cutting the tariff rates and eliminating the non-trade barriers. In particular, in the case of exports of ASEAN6 to ASEAN6 the infrastructure is the important factor. Also, in the case of the exports of ASEAN6 to CLMV(Cambodia, Laos, Myanmar, and Vietnam), it is expected that eliminating non-tariff barriers and enhancing trade facilitations may play important roles in the progress of intra-regional trade. These results may provide the important implications for Southeast Asian countries, which are trying to promote intra-regional trade ahead of the constitution of ASEAN Economic Community by 2015. Southeast Asian countries could be evaluated to achieve a certain level of trade liberalization and economic integration through the formation of AFTA. But in order for Southeast Asia to develop to advanced economic integrated region it requires mutual cooperations and policy harmonizations among regional countries. Also, for the elimination of non-tariff barriers, promoting trade facilitations, and providing infrastructures, the administrative, legal, and institutional measures would have to be fulfilled in advance. In addition, capital investment for constructing infrastructures would be necessary to realize the intra-regional trade expansion. However, to achieve the goal, it would require a large capital investment and highly mandated policy considerations and harmonizations among Southeast Asian countries in terms of further trade liberalization and economic integration.

• Cross-Cultural Studies
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• v.33
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• pp.33-52
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• 2013

Haizi, who ended his life with suicide on the railroad at the age of 25, is a poet who implemented his unique poetic world alone without belonging to any of the existing Chinese poetry schools in the 1980s. The process that Haizi reveals self-inside through a poetic work is rather to hide self-inside paradoxically, too. Accordingly, even a work of figuring out the real intention, which is hidden in poetic dictions that he selected, will be meaningful. In this sense, this study tried to inquire into the poetic imagination and self-image that were revealed in poetry focusing on "Spring, Haizi of 10 People", which is a work of having his name as topic, with having been written at the time of suicide, among Haizi's many poetic works. In addition, it figured out Haizi's private conscious world through analyzing the poem titled "Facing the sea with spring blossoms", which was created ahead of death same as "Spring, Haizi of 10 People". Thus, the aim was to look back on significance of his death and to broaden the width of understanding about Haizi's poetry. As for Haizi, the death can be regarded as the completion of 'performance,' which is a kind of Haizi's own final art form. Hence, Haizi's suicide needs to be seen from the perspective dubbed the continuity of creation through this performance, not the discontinuance of creation caused by 'intended death' that the poet himself selected. In the wake of pursuing the poetic world of a gifted poet Haizi, who died early, that this study examined, there will be any poet of Korea who is recalled naturally. One poet will be first recalled Yi Sang, who is a poet and a novelist of having been broadly known. Another poet is overlapped Gi Hyeong-do, who had been active as a poet and a journalist of having been dead after living in the similar period to Haizi. A comparative analysis among works by these Korean and Chinese poets has similarity beyond the temporal space. A research on this is thought to have value of being considered a little more deeply and generally hereafter. Still, this study mentioned only possibility of a comparative research on this.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.273-284
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• 2018

Purpose: Conventional headland turning typically requires repeated forward and backward movements to move the farming equipment to the next row. This research focuses on developing an upland agricultural robot with an optimized headland turning mechanism that enables a $180^{\circ}$ turning positioning to the next row in one steering motion designed for a two-wheel steering, four-wheel drive agricultural robot named the HADA-bot. The proposed steering mechanism allows for faster turnings at each headland compared to those of the conventional steering system. Methods: The HADA-bot was designed with 1.7-m wide wheel tracks to travel along the furrows of a garlic bed, and a look-ahead path following algorithm was applied using a real-time kinematic global positioning system signal. Pivot turning tests focused primarily on accuracy regarding the turning radius for the next path matching, saving headland turning time, area, and effort. Results: Several test cases were performed by evaluating right and left turns on two different surfaces: concrete and soil, at three speeds: 1, 2, and 3 km/h. From the left and right side pivot turning results, the percentage of lateral deviation is within the acceptable range of 10% even on the soil surface. This U-turn scheme reduces 67% and 54% of the headland turning time, and 36% and 32% of the required headland area compared to a 50 hp tractor (ISEKI, TA5240, Ehime, Japan) and a riding-type cultivator (CFM-1200, Asia Technology, Deagu, Rep. Korea), respectively. Conclusion: The pivot turning trajectory on both soil and concrete surfaces achieved similar results within the typical operating speed range. Overall, these results prove that the pivot turning mechanism is suitable for improving conventional headland turning by reducing both turning radius and turning time.

• Journal of Convergence for Information Technology
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• v.9 no.9
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• pp.33-37
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• 2019

According to the enforcement of the Cloud Computing Development and User Protection Act, a new paradigm called as Cloud Computing is coming to the fore among public and private domestic enterprises. Therefore, domestic companies should develop SaaS products specialized for the domestic market and try to preempt the IaaS market ahead of global companies. Now we are facing a necessity to combine all the cloud systems in Korean government to operate seamlessly in a harmony. In this paper, we will look at the prospect of future development of related industry through cloud computing concept and G-cloud's cloud management system (G-CMS). G-CMS can be seen as the first system to comprehensively manage heterogeneous Unix virtualization systems. G-CMS can also save costs by managing heterogeneous virtualization systems in data centers.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.121-128
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• 2021

In this paper, we propose a path generation and tracking algorithm of an unmanned air vehicle in a two-dimensional plane given the initial and final points. The path generation algorithm using the Dubins curve proposed in this work has the advantage that it can be applied in real time to an unmanned air vehicle. The path tracking algorithm is an algorithm similar to the line-of-sight induction algorithm. In order to efficiently control the direction angle, a gain related to the look ahead distance concept is introduced. Most of UAVs have the limited maximum curvature due to the structural constraints. A numerical simulation is conducted to follow the path generated by the sliding mode controller considering the angular velocity limit. The path generation and tracking performance is verified by comparing the suggested controller with conventional control techniques.

• The Journal of Korea Robotics Society
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• v.17 no.2
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• pp.142-151
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• 2022

With the advent of the 4th industrial revolution, autonomous driving technology is being commercialized in various industries. However, research on autonomous driving so far has focused on platforms with wheel-type platform. Research on a tracked platform is at a relatively inadequate step. Since the tracked platform has a different driving and steering method from the wheel-type platform, the existing research cannot be applied as it is. Therefore, a path-tracking algorithm suitable for a tracked platform is required. In this paper, we studied a path-tracking algorithm for a tracked platform based on a GPS sensor. The existing Pure Pursuit algorithm was applied in consideration of the characteristics of the tracked platform. And to compensate for "Cutting Corner", which is a disadvantage of the existing Pure Pursuit algorithm, an algorithm that changes the LAD according to the curvature of the path was developed. In the existing pure pursuit algorithm that used a tracked platform to drive a path including a right-angle turn, the RMS path error in the straight section was 0.1034 m and the RMS error in the turning section was measured to be 0.2787 m. On the other hand, in the variable LAD algorithm, the RMS path error in the straight section was 0.0987 m, and the RMS path error in the turning section was measured to be 0.1396 m. In the turning section, the RMS path error was reduced by 48.8971%. The validity of the algorithm was verified by measuring the path error by tracking the path using a tracked robot platform.