• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.9
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• pp.739-745
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• 2014

Although medication is given to heart disease patients, conventional medication alone is not sufficient to treat heart disease. However, it has been reported that left ventricular assist device (LVAD) transplantation is an effective bridge to heart transplantation by assisting cardiac function. This study used long-term animal testing and emergency situations with a bovine model (Holstein) and canine model (Labrador-retriever) to evaluate the biocompatibility of LibraHeart-I (LH-1), which is a bent-tube type of LVAD that was developed in a previous study. In the long-term animal testing with the bovine model, the subjects survived for 49 days with no irregularities observed in their complete blood cell counts or the vital sign tests that were carried out during the test period. In short-term animal testing with the canine model, it was observed that blood did not remain inside the LH-I even without power support from an external drive source. In this study, the biocompatibility of the LH-I that was developed in a previous study was verified by the ejection performance during long-term animal testing and emergency situations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.7
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• pp.575-583
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• 2017

This paper describes the design and evaluation of a driving mode decision algorithm for automated driving for merge situations on highways. For the development of a highly automated driving control algorithm for merge situations, the driving mode decision is crucial for merging appropriately. There are two driving modes: lane keeping and lane changing (merging). The merge mode decision is determined based on the state of the surrounding vehicles and the remaining length of the merge lane. In the merge mode decision algorithm, merge possibility and the desired merge position are decided to change the lane safely and quickly. A safety driving envelope is defined based on the desired driving mode using the information on the surrounding vehicles' behaviors. To obtain the desired steering angle and longitudinal acceleration for maintaining the subject vehicle in the safe driving envelope, a motion planning controller is designed using model predictive control (MPC), with constraints that are decided considering the vehicle dynamics, safe driving envelope, and actuator limit. The proposed control algorithm has been evaluated via computer simulation studies.

• Journal of Animal Environmental Science
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• v.18 no.1
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• pp.35-44
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• 2012

This study was carried out to investigate the current status of management skill such as participation of consulting, vaccination program, financial projects, etc, and manures treatment system in pig farms. Data surveyed from a total of 100 farms including reproductive sow and fattening pig were collected and analyzed. The results obtained were as follows; 1. Farmers participated in consulting education of 4.56 times per a year. Evaluation of vaccination program was 3.86 of 5 points. The control of hygiene and disinfection was evaluated with the average of 3.27 points. Financial management showed the low level with 2.82 points. And then, the level of technical skill on raising was evaluated with average of 3.21 points. 2. The fields of competitive strength in farms, first of all, were the disease disinfection and therapy for pigs (43.4%). Secondly, farmers answered the productive skill for environmental-friendly animal products (37.4%). 3. Collection systems of manures were mainly used the slurry system (44.0%), and scraper method (43.0%) in pig farms, respectively. 4. Manures collected from farms have been treated and utilized with form of land-return after organic matters resolution (32.3%).

• Journal of Educational Research in Mathematics
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• v.20 no.4
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• pp.459-476
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• 2010

The purpose of this study is to suggest a new direction in using LOGO as a gifted education program and to seek an effective approach for LOGO teaching and learning, by analyzing the strategic thinking of mathematically gifted elementary students. This research is exploratory and inquisitive qualitative inquiry, involving observations and analyses of the LOGO Project learning process. Four elementary students were selected and over 12 periods utilizing LOGO programming, data were collected, including screen captures from real learning situations, audio recordings, observation data from lessons involving experiments, and interviews with students. The findings from this research are as follows: First, in LOGO Project Learning, the mathematically gifted elementary students were found to utilize such strategic ways of thinking as inferential thinking in use of prior knowledge and thinking procedures, generalization in use of variables, integrated thinking in use of the integration of various commands, critical thinking involving evaluation of prior commands for problem-solving, progressive thinking involving understanding, and applying the current situation with new viewpoints, and flexible thinking involving the devising of various problem solving skills. Second, the students' debugging in LOGO programming included comparing and constrasting grammatical information of commands, graphic and procedures according to programming types and students' abilities, analytical thinking by breaking down procedures, geometry-analysis reasoning involving analyzing diagrams with errors, visualizing diagrams drawn following procedures, and the empirical reasoning on the relationships between the whole and specifics. In conclusion, the LOGO Project Learning was found to be a program for gifted students set apart from other programs, and an effective way to promote gifted students' higher-level thinking abilities.

• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.1
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• pp.2503-2519
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• 1972

The studies were carried out to find the cause and the quantitative evaluation of sea dike materials loss which is occured during the period of construction works for the tideland reclamation projects on the west coast of Korea. Major subjects to studies were to establish the typical relationships between the tidal flow and the movement of dike materials, the tidal-flow and the erosion, the dike materials and the ratio of material movement(losses), construction methods and the ratio of materials movement (losses). Based on the above subjects, the studies were made for the purpose of obtain the following informations; (1) Collecting and evaluaing the data of dike material losses due to foundation settlement, from designed existing dikes on the west coast. (2) By the field investigation at A-San Sea Dike, Pyong Taek Project, the Comparison would be made by the relationships between the tide velocity and the movement of dike foundation under the natural conditions and the period of construction so that find out the relationship between the dike materials of foundation situation and settlements. With regard to the dike construction works, it is so difficult to calculate the exact quantity of material losses due to the foundation settlements. The major factors that affect the settlement losses of the dike materials are: (1) Topographical variation (2) Swepting the sectional area of dike by the tide velocity. (3) Dumping riprap to the outerside of dike during the period of construction works. (4) Sectional area losses by the cause of occurence of the new tide channels. (5) material losses by the heavy storms. (6) Consolidation settlement by the foundation weakness. (7) Material losses by the earth materials by tide flow. Most hi호 material losses were occured by the Consolidation settlement due to the foundation weakness, the maximum tide velocities due to decrease the cross sectional area of the gaps and erosion of foundation due to the range of tide, Inner and outerside of dike, or dike material loses due to the tide flow. Final conclusion would be obtained by the continuous measurement of consolidation settlement at the stage of final clusure of the dike. (It is scheduled to close on the end of 1972) However, intermediate conclusion can be introduced as follows: (1) The estimation of material(losses) during the period of construction works for the existing sea-dikes up to date were only empirical. The material losses at the general closure for design was estimated at 10% of the riprap, 20% of the earth materials, and 20% of the riprap, 40% of the earth materials at the final closure of the dike. The final closure estimated double quantity to the general closure, but it is still doubt. (2) The ratio of consolidation settlements was found smaller than the calculated quantity. It can be foreseen that settlement speeds is higher thom the calculated speeds. (3) The movement of dike foundation under the natural conditions were not so depends on the geological conditions of the foundation. (4) When the tide velocities was estimated 100 at the normal tide, it was estimated 125 at the high tide and 55 at the low tide. The tide velocities at the low tide shows apparently lower than the high tide and the higher velocities at the deep water depth.

• Korean Security Journal
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• no.32
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• pp.205-225
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• 2012

This study is to present an improvement of facility security through the evaluation of facility security operation level. To fulfill the purpose of the study, a survey of some facilities was conducted and the result was analyzed as follows; First, although security personnels were deployed in the facilities, the level of security personnel operation was relatively low. Second, job education training level was relatively proper, that is relevant to the result that show the level of service mind and the working mind of security personnel were proper, also relevant to the relatively good work shift system. Third, although situation room was operated well, the level of restricted area set-up and access control of visitor were low, and the level of article inspection and vehicle access control were very low. Forth, the level of security manual application that include detailed security method and procedure was proper. But accident prevention and response manual application was lower than security manual application, that show preparation for fire and negligent-accident is passive. For the improvement of facility security, the high level part and low level part in the survey result could be merged. For example, we could specify factors that show low level in the survey such as security personnel operation, access control of visitor and vehicle, article inspection, accident prevention and response in the security manual and promote education circumstance that show high level.

• Korean Security Journal
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• no.17
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• pp.91-107
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• 2008

This study aims to grasp the general conditions regarding university students in security related majors in Korea. Followings will be covered here: what motivated them to choose those majors, hw much are they git jobs through the education, what is their conscioucness on their majors, jobs, and courses like, and what effects their job preference. And ths study also aims at helping the student with their future plans such as admission to a school of higher grade and choosing their job. For this study, we distributed 340 copies to the students in security related majors at 4 four-year colleges and 1 two-year college, and collected 298 copies by means of quota sampling method. For collected questionnaires, we used individual T-test verification and one-way ANOVA analysis to grasp the situation. Significance stabdard for the test results was set as p<0.05. Followings are the test results. The results on analysis of satisfaction rate on their curriculums, classes, and majors show that students in security-related majors showed different satisfaction rate and different averages according to their sex and the year of the college. In the analysis on the relationship between major education and employment of students in security-related majors, the result of curriculum improvement and scholaril attainments analysis showed statistically significant relation. When students in security-related majors were surveyed on their consciousness of their future plans such as getting jibs, two-year college students had more certificates of qualification for employment than four-year college students.

• Journal of Korean Physical Therapy Science
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• v.27 no.2
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• pp.25-35
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• 2020

Background: There are many situations where walking in an actual community needs to change direction along with walking on a straight path, and this situation needs to be reflected in assessing walking ability of the community. Therefore, in this study, we tried to determine whether the assessments can distinguish the level of walking in the community. Design: Retrospective cohort study. Methods: Fifty-two survivors with chronic stroke have participated in the study. According to the evaluation result of 10mWT, the subjects of 0.8m/s and above were classified as the group who could walk in the community (n=22), and the subjects of 0.4m/s~0.8m/s were classified into the group who could not walk in the community (n=30). Modified Rivermead Mobility Index, Postural Assessment Scale for Stroke, Fugl-Meyer Assessment, Berg Balance Scale, 10-meter Walk Test (10mWT) were used to evaluate the motor skills. Furthermore, Activities-specific Balance Confidence Scale was used to evaluate psychological factors, and Timed Up & Go Test (TUG), Figure-of-Eight Walk Test (F8WT), Four Square Step Test (FSST), Step Test (ST) were applied to evaluate dynamic balance and mobility. Results: As a result for distinguishing walking levels in the community, TUG was 14.25 seconds, F8WT was 13.34 seconds, FST was 19.43 seconds, and ST of affected side and non-affected side were 6.5 points and 7.5 points, respectively. TUG (AUC=0.923), F8WT (AUC=0.905), and FST (AUC=0.941) were highly accurate, but the ST of affected side and non-affected side (AUC=0.806, 0.705) showed the accuracy of the median degree, respectively. Conclusion: To distinguish walking levels in the community of survivors with chronic stroke, TUG and FSST have been found to be the best assessment tool, and in particular, FSST could be very valuable in clinical use as the most important assessment tool to distinguish walking levels in the community.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.726-733
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• 2016

Recently, the flood frequency and magnitude have increased due to heavy rainfall. Considering the present condition, a flood risk map has been published in many countries to raise awareness about flood damage to people. A flood inundation analysis model, which is used to publish the flood risk map, can be classified as river and inland inundation models according to the inundation cause. Although a variety of flood inundation analysis models are utilized both domestically and overseas, their usability is limited by the expensive price, except for the HEC-RAS model developed by U.S. Army Corps of Engineers (USACE). In the situation, the USACE has developed a 2-D HEC-RAS model that can be linked to the existing 1-D model. This model has been released as a beta version under the name, HEC-RAS 5.0. In this study, the HEC-RAS 5.0 model's features, usability, applicability, and accuracy were evaluated by comparing the performances on Gokgyo-cheon with the FLUMEN model, which is used for domestic flood risk mapping. The results of this study will contribute to river inundation analysis in many different ways after the HEC-RAS 5.0 model is stabilized.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.95-120
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• 2011

Modern society is the age of the information. As new information is springing up every day and pace of change becomes faster, the importance of communication skills is growing. The recent mathematics education is recognized as not a fragmentary mathematical knowledge or results of the learning, but a procedure of mathematical thinking, and the effective expression skill of their mathematical ideas and the ability to forward it to others are regarded very serious. As the method of mathematics evaluation, mathematical essay is introduced to replace the existing multiple-choice written test. This method assess the ability which students have, that express the reorganized knowledge and information according to given situation by themselves. Ultimately, it is expected to help that students get the higher order thinking skills such as logical thinking and creativity. However, definition of elementary mathematical essay is unclear, and proper teaching methods is lacking for each stage of elementary school students. Thus, in this paper, I have defined the concept of elementary mathematical essay and made a foundation of elementary mathematical essay research, then researched about the effective utilization of elementary mathematical essay using school education. Also elementary mathematical essay teaching-learning materials is developed and applied to analyzed the students' responses. Using this program, in real elementary school education, the implications has deduced.