• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.56-56
• /
• 2017

점적 호스 중 PC 드립은 경질 호스의 내부에 Micro-path가 부착된 유로장치와 압력을 보상하는 연질의 실리콘으로 구성되어 있다. 이때 일정압력에서 적정 길이까지 동시에 내부 압력을 유지하며 균등하게 유출구를 통하여 유량을 공급하는 압력보상 기능이 매우 중요하다. 그러나 이 부분에 대한 기술은 선진국에 비해 아직 부족하여 수입에 의존하는 경향이 매우 높다. 뿐만 아니라 선진국 제품에 비해 유로장치 및 연질 실리콘의 탄성이 균일하지 못해 압력에 따른 유량의 편차가 큰 편이다. 본 연구에서는 우리나라 제품의 PC 드립 압력 균등성 기술을 향상시키기 위해 PC 드립의 핵심기술인 연질 실리콘의 성능에 대한 평가와 유량의 편차를 분석하여 문제점을 통한 개선방안을 제시하고자 하였다. 연질 실리콘의 규격은 $17{\times}8{\times}0.85mm$ (가로${\times}$세로${\times}$두께)로서 Water line의 내부에 결합되어 구성된다. PC 드립용 실리콘은 국내 A사 제품을 중심으로 하여 성능을 측정하였다. 측정을 정밀하게 하기 위해 Microtester를 사용하여 일정하게 하중이 부과되도록 하였다. 연질의 실리콘의 경도는 압력 보상에 중요한 기능을 하고 있으며 또한 PC 드립의 경질 미로와 같이 압력을 제어하는 역할을 하고 있다. 국내 A사의 실리콘 경도는 이상적인 실리콘 경도에 비하면 매우 불균일하였다. 세부적으로는 40 이하의 낮은 경도에서는 비교적 일치하였으나 경도 45 이상에서는 큰 차이를 보여주고 있었다. 국내 A사의 실리콘 경도에 따른 공급유량의 특성에서는 실리콘의 경도가 낮을수록 실리콘은 무르며 탄성이 줄어든다. 반면에 경도가 높을수록 탄성이 커지고 딱딱한 특성을 가진다. 동일한 PC 드립에 실리콘의 경도별 특성은 경도에 따른 유량이 반드시 일정하지 않으며 대체로 경도가 높을수록 동일 압력에 대해 유량이 많아지는 것을 알 수 있었다. 압력의 변화에 대해 유량이 일정하게 유지하는 특성을 가질수록 사용범위가 넓어지고 안정성이 높은 것으로 판단되며 실리콘 경도 35~55 범위에서 1~2bar의 공급압력에서 사용하는 것이 적합할 것으로 보여진다. 경도 45의 실리콘을 사용하여 수입 드립, 국내 A사의 드립 및 수입과 국내 혼용시 압력에 따른 공급유량의 특성을 분석하였다. 최대 유량과 최소 유량에서 발생되는 오차는 수입 실리콘이 비교적 작았으나 3.6 bar 이상에서는 유량이 급격히 떨어지는 양상을 보였다. 국내 A사의 제품은 0.8~2.0 bar 까지 성능이 비슷했으나 0.8 bar 이하에서는 오차가 있었으나 높은 압력에서는 오히려 성능이 우수하였다. 수입 드립과 다소 유사한 성능을 나타낸 것이 A사 드립과 수입 실리콘을 혼용하여 사용한 것은 전체적으로 비슷한 양상을 나타내었다. 따라서 실리콘 경도 오차를 고려하면 압력별 유량의 변화는 실리콘의 경도와 밀접한 관계가 있는 것으로 판단되었다.

• Journal of the Korean Regional Science Association
• /
• v.9 no.1
• /
• pp.45-63
• /
• 1993

University enrollment has long been regarded as one of the major factors inducing population concentration in Seoul and the Capital Region of Korea. Consequently, since early 1980's increases in enrollment and new establishments of extention universities beyond the boundary of Seoul, has been promoted, while university enrollment quota in Seoul has been strictly controlled. The degree of actual population dispersal, however, resulting from such a university enrollment policy has not been empirically tested. This paper aims at: First, identifying the trend of population growth and evolution process of the university enrollment policy in the Capital Region; Second, comparing the degree of influence of university enrollment on population concetration factors; Third, measuring actual effect of the enrollment control on population dispersal out of Seoul and the Capital Region. Major findings are as follows: First, only a week correlation between population and university enrollment growth trends was found; Second, the relative degree of influence on population concentration in the Capital Region, were order, in the order of magnitude, the physical amenity factor, the socio-cultural amenity factor, the employment climate factor and the educational factor. Third, and most improtant, based on the comparison of spatial distribution of graduated high schools and current residence of the selected university students, the gap between the two distributions was revealed and the inter-regional student population movement was estimated. The result shows that in Seoul's case about one-half of and in Kyunggi Province's case about one-fifth of university enrollment size, contributes to population concentration into Seoul. Fourth, as to the universities outside of the Capital Region, little effect in the case of universities located within the commuting distance, and a little effect on population dispersal in the case of universities located beyond commuting distance, were found. In sum, it seems clear that university enrollment policy in the Capital Region, especially in Inchon/Kyunggi Province has not been effective on student population dispersal out of Seoul and the Capital Region. Therefore, it is strongly recommended that university enrollment policy be throughly re-examined from its goal to the implementation means.

• Journal of Engineering Education Research
• /
• v.9 no.2
• /
• pp.82-97
• /
• 2006

University entrance for technical high school students in Japan is politically promoted from a viewpoint of lifelong learning. Therefore, the Japanese universities (faculty of engineering) are pressed on the necessity of making the reform for educational methods which are based on the premise of systematic study from high school to university. In Nagasaki University, the special entrance of students who were graduated from technical high school was started from 1995. Now, we are strengthening basic academic ability for them by developmental (remedial) education under a new educational-learning model called "engineering power" cultivation. We are promoting the examination of the instructional method and the development of teaching-materials, which become adequate to the student's actual condition, with technical high school teachers and the professors of our university through the observing of student's learning process and their lesson.

• Asian Journal for Public Opinion Research
• /
• v.5 no.4
• /
• pp.319-345
• /
• 2018

Effective higher educational management in undergraduate nursing programs is an important issue from the viewpoint of stakeholders. This qualitative research aimed to examine the characteristics of nursing students and curriculum development of undergraduate nursing education from the opinions of Boromarajonani College of Nursing Saraburi, Thailand stakeholders. The population included 4 groups: 1) the alumni who have graduated within the past 5 years and currently work in primary, secondary, and tertiary care units, 2) the supervisors and colleagues of the alumni, 3) nursing lecturers, and 4) the current nursing students. The respondents who are the alumni, nursing lecturers, and current nursing student were selected using a purposive sampling, for the supervisors and colleagues were selected using snowball techniques. Semi-structured interview questions were used for data collection. Group discussions were conducted until saturation on 55 key informants. The qualitative data was analyzed using content analysis. Results showed the viewpoints of stakeholders on the characteristics of future nurse graduates were comprised of four elements: knowledge that meets standards; essential skills for self-development and lifelong learning process; good morals and professional ethics in providing nursing care; and nurse competencies in teamwork, communication, language, research, management, IT, life skills, and global literacy. The viewpoints on the development of the nursing curriculum focus on four elements: the learner, teaching and learning, course content, and instructor tasks. For learners, the admission criteria should include a minimum not only of knowledge, but also positive attitude, science, and art skills, since the nursing profession is both a science and the art of caring. Teaching and learning elements should be authentic, including exposure to real situations, an integrated network, and activities that improve nursing care. Course content was comprised of an updated curriculum, humanized nursing care, student center, theory and practice with moral integration, case-based study, critical thinking, multidisciplinary work, and love for the nursing profession. Instructor tasks are to elicit student ideas, provide opportunities to learn, support infrastructure, support technology use, and extra-curricular activities to develop the competencies of nursing students. Recommendations were that the curriculum administration should review the selection process of student candidates and instructional management to achieve expected outcomes of nursing characteristics in the future. The nurse lecturer should provide authentic and integrated instruction, decrease lecturing, cultivate a lifelong learning process, and sustain the nursing characteristics.

• Journal of Korea Society of Industrial Information Systems
• /
• v.23 no.6
• /
• pp.67-77
• /
• 2018

Currently, there are many problems due to the decline in school-age population. Moreover, Korea has the largest number of universities compared to the population, and the university enrollment rate is also the highest in the world. As a result, the minimum student retention rate required for the survival of each university is becoming increasingly important. The purpose of this study was to examine the effects of reducing the number of graduates of education and the social climate that prioritizes employment. And to determine what the basic direction is for students to manage the student retention rate, which can be maintained from admission to graduation, to determine the optimal input variables, Based on the input parameters, we will make associative analysis using apriori algorithm to collect training data that is most suitable for maintenance rate management and make base data for development of the most efficient Deep Learning module based on it. The accuracy of Deep Learning was 75%, which is a measure of graduation using decision trees. In decision tree, factors that determine whether to graduate are graduated from general high school and students who are female and high in residence in urban area have high probability of graduation. As a result, the Deep Learning module developed rather than the decision tree was identified as a model for evaluating the graduation of students more efficiently.

• Journal of The Korean Association For Science Education
• /
• v.17 no.2
• /
• pp.127-137
• /
• 1997

The purpose of this study was to assess elementary student's ability of measuring length, area, and volume and reading metric scales. The findings of this study were as follows. All students were successful in measuring without scale, regardless of grades. But they were less successful in measuring the task using standard and nonstandard scales. Especially, in measuring area, lower grade students were not able to perform the task using nonstandard instruments, but higher grade students were able to perform the task. Measuring area using grade paper was least successful for sixth graders. In measuring volume, students under fifth grade read the upper scale when using graduated cylinder. In measuring by direct comparison, students were more successful in measuring length than in measuring area and volume using given material. The use of given nonstandard material was successful for 4th, 5th, and 6th grade students. In measuring using metric scale, lower grade students did not pay attention to the zero of the scale, but just read the end point. Higher grade students considered both zero and end points.

• Journal of Korean Home Economics Education Association
• /
• v.7 no.2
• /
• pp.113-123
• /
• 1995

The purpose of this study is to investigate teachers’ recognition in Food/Nutrition, Textile/Clothing part in Home Economics Text Book of Middle School and to provide the basic data for the improvement of its curriculum. 147 Home Economics teachers in Taegu city and Kyungsangbukdo area responded to the questionnaire. The results are summarized as follows: 1. Most of Home Economics teachers have graduated Dept. of Home Economics Education and have ever taken teacher training. And even those who ever taken teacher training are not satisfied with training curriculum contents. Therefore, the result of this study shows that teacher training curriculum contents should be improved so as to be helpful for the actual teaching and learning. 2. In terms of the suitability of contents of food & nutrition and contents of textiles & clothing to the student’s learning development levels, the degree of suitability is in the order of nutrition & health, nutrition in adolescence, food selection, kinds and functions of nutrients in food & nutrition curriculum, and in the order of suitable clothing, mixture rate of fabrics, purchase of clothing, clothing in adolescence, clothing selection. The contents of making processed foods and usage of sewing machine of the existing text book have turned out not to be appropriate. 3. Most teachers suggest that dietary guideline for health, misconception about food & nutrition selection of ready-made suit suitable clothing for situation & character as well as the contents of the existing text book should be included in the new text book.

• Journal of Mechanical Science and Technology
• /
• v.15 no.8
• /
• pp.1097-1107
• /
• 2001

In this paper, the wall following navigation algorithm of the mobile robot using a mono vision system is described. The key points of the mobile robot navigation system are effective acquisition of the environmental information and fast recognition of the robot position. Also, from this information, the mobile robot should be appropriately controlled to follow a desired path. For the recognition of the relative position and orientation of the robot to the wall, the features of the corridor structure are extracted using the mono vision system, then the relative position, the offset distance and steering angle of the robot from the wall, is derived for a simple corridor geometry. For the alleviation of the computation burden of the image processing, the Kalman filter is used to reduce search region in the image space for line detection. Next, the robot is controlled by this information to follow the desired path. The wall following control scheme by the PD control scheme is composed of two control parts, the approaching control and the orientation control, and each control is performed by steering and forward-driving motion of the robot. To verify the effectiveness of the proposed algorithm, the real time navigation experiments are performed. Through the result of the experiments, the effectiveness and flexibility of the suggested algorithm are verified in comparison with a pure encoder-guided mobile robot navigation system.

• Journal of the Society of Disaster Information
• /
• v.5 no.2
• /
• pp.88-106
• /
• 2009

The potential risks of Korean public security has been increasing by economic stagnation. As a result of this, a feeling of unrest about our society causes expansion of private security industry as well as necessity of professional education. It has been 15years to produce security expert in colleges which is professional education institute, and academic efforts and contributions to society are shown remarkable results for the period. A private security industry had got public interest as a potential favorable job, because of increasing dependence of public to take care of unrest facts. Many colleges have introduced courses about public security because of facing necessity of professional education system. Then total 59 institutes including 22 universities and 37 colleges introduce courses of public security. Although name of courses are diverse depends on institution, purpose of course or members of course, the ultimate purpose of these courses is preventing public from crimes and managing public security. A fixed and out of date education system of universities in Korea can not produce talent person who people, companies and government want. The institutions have been recruiting many student so far, and it shows growth of the industry in quantity aspects. However quality aspect of the industry has been failed because it is hard to get a job for graduated students. Consequently, to improve quality of the industry people need cooperation of institution, professors and students.

• Journal of Ocean Engineering and Technology
• /
• v.34 no.4
• /
• pp.237-244
• /
• 2020

In this study, we investigate surge force, heave force, and pitch moment, which are vertical plane hydrodynamics acting on Manta-type unmanned underwater vehicles (UUVs), using a model test and computational fluid dynamics (CFD) simulation. Assessing the maneuvering hydrodynamic characteristic of an underwater glider in the initial design stage is crucial. Although a model test is the best approach for obtaining the maneuvering hydrodynamic derivatives for underwater vehicles, numerical methods, such as Reynolds averaged Navier-Stokes (RANS) equations, have been used owing to their efficiency in terms of time and cost. Therefore, we conducted an RANS-based CFD calculation and a model test for Manta-type UUVs. In addition, we conducted a validation study through a comparison with a model test conducted at a circular water channel (CWC) in Korea Maritime & Ocean University Furthermore, two RANS solvers (Star-CCM+ and OpenFOAM) were used and compared. Finally, the maneuvering hydrodynamic forces obtained from the static drift and resistance tests for a Manta-type UUV were presented.