• Journal of Welding and Joining
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• v.12 no.3
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• pp.109-117
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• 1994

Spot welding has wide used with a high work efficiency in the automotive and aerospace industries. Up to the present, the technique mainly used to test spot welds on production lines has been entirely depended upon destructive chisel or peel testing. Therefore, it's being very important assignment to secure the NDE technique which can be evaluate spot weld quality with more efficiency and high reliability. This paper discusses the feasibility of UNDE techniques to evaluate spot weld quality. For the sake of the approach to the quantitative measurement of nugget diameter and the discrimination of a the corona bond from nugget, ultrasonic c-scan image and distribution of reflective echo amplitude was measured by immersion method with the mechanical and the electronic scanning of point-focussed ultrasonic beam(25 MHz). As the results of this study, corona bond which is the most dangerous types of interface defects can be successfully detected, as well as expulsion and voids. Ultrasonic testing results were confirmed and compared by optical microscope and SAM(Scanning Acoustic Microscope) observation of the spot-weld cross section. The results show that the nugget diameter can be successfully measured with the accuracy of 0.8 mm.

• Journal of the Korea Society of Computer and Information
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• v.22 no.10
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• pp.179-187
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• 2017

In spite of the rapid change of the technology, the university education cannot escape from the traditional form of classroom teaching. University education is assessed through listening the same content of lecture, completing the same assignment and test at the same time, same place. To prepare for the 4th industrial revolution, it is investigated to reorganize the curriculum(32.5%), strengthen the lifelong education(21.4%), expand the compulsory education(17.6%), expand the innovation school(13.7%), expand the educational finance(10.4%) as the field of education which need to be strengthen. The change of the education is essential to prepare for the 4th industrial revolution which creativity, collaboration, fusion, problem solving are the core ability. In this thesis, it is to be compared that the subjects opened in liberal arts of domestic and overseas university in this 4th industrial revolution and Basic Liberal Art Education Curriculum is promoted for the smooth management for preparing the future and taking the action to the change. Stereotyped and inflexible frame should be changed to 'Structure', 'Recognition', 'Attitude' for making the base of 'Diversity', 'Personalization', 'Flexibility' which are needed to uplift 'Imagination', 'Creativity' for education of the future and the new era.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.109-113
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• 2002

Steel industry is the most capital intensive and the largest energy consuming industry, which operate huge and complex facilities to supply various steel products as the primary materials to almost every manufacturing industry Major steel products are hot-rolled and cold-rolled coils, plates, and wires that are produced through molten iron making, molten steel making, casting, and rolling. Each process runs in batch between setups and the specifications or bach are different with each other High energy consuming and heavy material handling require careful synchronization or processes, as well. Considering the synchronization or processes, the lot planning and scheduling problem in the integrated steelmaking process rovers the roll grouping with given casts. the sequencing or rolls over time, and the machine assignment and time scheduling or charges and casts. The problem is investigated by dividing it into two cases whether single or parallel machines at the molten steel making and the continuous casting processes. Problem descriptions and solution approaches or each instance are introduced. To test their performance and conformity, implementation or the algorithms and numerical experiments are carried out with real world and constructed data sets.

• Spatial Information Research
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• v.5 no.2
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• pp.177-183
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• 1997

S1he concept of a class in the land-use classification system can be equally applied to a class in the land-use-change classification. The maximum likelihood method using linear discriminant function and Markov transition matrix method were integrated to a synthetic modeling effort in order to project spatial allocation of land-use-change and quantitative assignment of that prediction as a whole. The algorithm of both the multivariate discriminant function and the Markov chain matrix were discussed and the test of synthetic model on the study area was resulted in the projection of '90 year as well as '95 year land -use classification. The accuracy and the issue of modeling improvement were discussed eventually.

• PNF and Movement
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• v.6 no.3
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• pp.1-9
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• 2008

Purpose : The purpose of this study was to analyze the reaction of recovery for the fatigue by sports massage treatment after Taekwondo training and then to verify the effectiveness. Subject : The subjects of this study were all the 20 high school Taekwondo players divided into two groups (rest recovery group and sports massage group) selected by systematic random assignment sampling. Method : The variables were the level of hemoglobin, lactic acid and glucose, and measured at rest, immediately-after exercise and 30-minute recovery. The data from this study were analyzed by using one-way ANOVA, independent sample t-test. Results : The results are as follows ; 1. The measurement of the hemoglobin, there was not the significant differences between experiment group and control group. 2. The lactate showed lower in the experiment group than in the control group in 30-minute recovery (p<.001). 3. The glucose showed lower in the experiment group than in the control group in 30-minute recovery (p<.01). So I think the sports massage treatment is more effective in the relief of fatigue than static rest method during the recovery after sports. However the massage treatment influence on the activation of metabolism according to the intensity and the duration of sports, and vary the effect of treatment according to the method and execution time. Therefore the longitudinal investigation of the variation by the long time massage through the more detailed program must be requisite for us.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.1
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• pp.16-24
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• 2011

Automotive Radar Systems are currently under development for various applications to increase accuracy and reliability. The target tracking is most important in single or multiple target environments for accuracy. The tracking algorithm provides smoothed and predicted data for target position and velocity(Doppler). To this end, the fixed gain filter(${\alpha}{\beta}$ filter, ${\alpha}{\beta}{\gamma}$ filter) and dynamic filter(Kalman filter, Singer-Kalman filter, etc) are commonly used. Gating is used to decide whether an observation is assigned to an existing track or new track. Gating algorithms are normally based on computing a statistical error distance between an observation and prediction. The data association takes the observation-to-track pairings that satisfied gating and determines which observation-to-track assignment will actually be made. For data association, NNPDA(Nearest Neighbor Probabilistic Data Association) algorithm is proposed. In this paper, we designed a target tracking system developed for an Automotive Radar System. We show the experimental results of the 77GHz FMCW radar sensor on the roads. Four tracking algorithms(${\alpha}{\beta}$ filter, ${\alpha}{\beta}{\gamma}$ filter, 2nd order Kalman filter, Singer-Kalman filter) have been compared and analyzed to evaluate the performance in test scenario.

• Journal of Korean Elementary Science Education
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• v.20 no.1
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• pp.45-57
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• 2001

The purpose of this study is to guide and apply gettable and accessible materials around everyday life into classroom instruction, and to find out their effects on student academic achievement. In order to achieve it, this study was tried to develop and guide available materials around life in teaming activities, to provide a preliminary assignment that could apply the available materials, and to compare its academic achievement to one from field trip loaming. For the hypothesis testing, first, the experimental and comparing classes were selected based on the results of basic learning diagnostic evaluation, which conducted by the researcher being served as a full-time science teacher of the third and sixth grade of K elementary school in Kwangju for 2 years. Secondly, the instructional use of the available materials around life was applied to the experimental class. Also, the instructional use of the existing materials was applied to the comparing class. Finally, for the testing of the effects on academic achievement, the posterio test was implemented after conducting the experimental instruction in knowledge·understanding, inquiry process, and attitude domains classified by the unit characteristics. Using SPSS/WIN program the t-test was performed in order to compare the differences between the two groups. Major findings were as follows: 1) In the achievement test of knowledge·understanding domain, there were no significant differences at the 5％ level between the experimental and comparing classes. It could be difficult to say, therefore, that the instructional use of the available materials around life was more effective than the instructional use of the existing materials. However, it had some effects on differences between the third grade final achievement test and sixth grade experimental class. 2) In the achievement test of inquiry process domain, there were some significant differences in that the sixth grade experimental class was higher than the third grade out-of classroom experience unit. It was indicated that the instructional use of the available materials around life had some effects on improving the students' inquiry ability 3) In achievement test of attitude domain, there were some significant differences. It was shown that the self-evaluation test of the sixth grade experimental class unit was higher than that of the third grade out-of classroom experience unit; Especially, the learning activities in the experimental class were more active, and the experimental practice ability was improved. It was presented that the instructional use of the available materials around life had some effects on the students' academic achievement in attitude domain. It was concluded from this study that the instructional use of the available materials around life was less effective on Knowledge understanding domain, but was effective on improving their scientific inquiry ability and interest on science education.

• Journal of Korean Academy of Nursing
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• v.22 no.4
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• pp.526-551
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• 1992

The purpose of this study was to identify the commonalities of various nursing interventions and effective intervention methods in each intervention through analysis and synthesis of many accumulated research papers. The study analyzed the effects of various nursing interventions on anxiety and /or stress. For this purpose, 64 experimental studies with randomized or nonequivalent control group pre-test-posttest design were selected from journals of medical and nursing schools, the Korean Nurse, the Korean Nurses' Academic Society Journal, the Cetnral Journal of Medicine, the New Medical Journal, the Nurse Monthly, and from theses and dissertations conducted from 1970 to 1991. The selected studies nor classified according to three characteristics : 1) the research samuel, 2) types and methods of nursing interventions, and 3) statistical tests. The following analysis was done : 1) Confirmation of the accuracy of data drawn from each study by paired review, 2) Estimation of the homogenity of pre-test scores of the dependent variable between control and experimental groups warranted the effect size of post-scores, 3) If the homogenity of pre-test scores did not warrant, the change scores from pre-test to post-test were used to estimate the effect size, 4) Use of the effect size of each study among homogenious studies was tested for each intervention method, such as relaxation, information, and touch and /or support. Finally, for the studies not showing homogenity, an ANOVA test was used to identify patterns for each intervention. Some findings are summarized as follow : The effect sizes for relaxation and information were greater than those for touch and /or supportive technique. Studies using random assignment had greater effect sizes than nonrandomized sample studies using the same intervention. For healthy people, group education was more effective than individual teaching. However, for patients, relaxation and touch and /or supportive techniques given on individual basis were more effective than when given in a group situation. Measuring anxiety and stress by biological indicators was less effective than by self-report. Budzynski's relaxation method was the most effective. The more frequently the techniques applied, the larger the effect size. On the bases of these findings, the following recommendations were made : 1. A combination of information, relaxtion, and touch-supportive techniques should be used for greater effect in reducing the level of anxiety and /or stress. 2. Information is the first choice of intervention to reduce the level of anxiety and /or stress of healthy People : other interventions may be added depending on the conditions of the subjects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.89-97
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• 2016

This paper addresses the problem of the construction planning of artillery positions, for which we present an optimization model and propose a heuristic algorithm to solve problems of practical size. The artillery position construction plan includes the assignment of engineers to support the artillery and the schedule of the support team construction sequence. Currently, in the army, managers construct the plan based on their experience. We formulate the problem as a mixed integer program and present a heuristic that utilizes the decomposition of the mixed integer model. We tested the efficacy of the proposed algorithm by conducting computational experiments on both small-size test problems and large-size practical problems. The average optimality gap in the small-size test problem was 6.44% in our experiments. Also, the average computation time to solve the large-size practical problems consisting of more than 200 artillery positions was 79.8 seconds on a personal computer. The result of our computational experiments shows that the proposed approach is a viable option to consider for practical use.

• Journal of Korean Academy of Nursing
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• v.30 no.4
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• pp.1035-1044
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• 2000

The purpose of this study was to develop and evaluate an internet based program for nursing informatics. The course subject, Nursing Informatics, was made by a computerized instructional module using the internet. The program was developed after taking into consideration the level of competence and knowledge in the subjects. It was based on 10 steps of the CAI module developed by Alessi and Trollip. The subjects consisted of 76 junior nursing students taking a Nursing Informatics course. Two sets of questionnaires were used for this study. First, a questionnaire was administered to 76 students to collect general information on their experience while using computers and the internet. Secondly, another questionnaire was administrated to 76 students after they took the course. They were asked to evaluate the program in terms of easiness of use, precision of contents, freshness of contents, motivation in learning, effectiveness of learning, enhancement of communication, precision of screen, and interest in the contents. IDs and passwords were given to the students. The students were asked to write their IDs and passwords when they connected to Nursing Informatics (http://hallym.ac.kr/~yhyom/ inform.html). They were led the menu page which was categorized into 8 icons (i. e., syllabus, lecture notes, quick test, Q & A board, assignment, on-line test, related web sites and mailing lists) after confirming their IDs and passwords. The students' responses were very positive. This program was a very useful in increasing the effectiveness of learning and motivation in the students. Suggest to be use for other nursing courses.