• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.437-442
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• 1998

Film boiling is the heat transfer mechanism that can occurs when large temperature differences exist between a cold liquid and hot material. In the nuclear reactor safety analysis, film boiling has become an important issue in recent years. During severe accident, hot molten corium fall into relatively cool water, and fragment into spheres or sphere-like particles. If the steam explosion is triggered, the thermal energy of corium is converted into the mechanical energy that can threaten the integrity of reactor vessel or reactor cavity. One of the important concerns in the heat transfer analysis during pre-mixing stage is the film boiling heat transfer between the corium and water/steam two-phase flow. Until now, considerable works on film boiling heat been performed. However, there is no available correlation adequate for severe accident analysis. In this study, boiling heat transfer correlations have been developed, and their applicable ranges heat been enlarged and their prediction accuracy has been enhanced.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.6
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• pp.560-567
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• 2007

The objective of this research is to optimize the designing parameters of the parallel manipulator with large orientation workspace at the boundary position of the constant orientation workspace (COW). The method uses a simple genetic algorithm(SGA) while considering three different kinematic performance indices: COW and the global conditioning index(GCI) to evaluate the mechanism's dexterity for translational motion of an end-effector, and orientation workspace of two angle of Euler angles to obtain the large rotation angle of an end-effector at the boundary position of COW. Total fifteen cases divided according to the combination of the sphere radius of COW and rotation angle of orientation workspace are studied, and to decide the best model in the total optimized cases, the fuzzy inference system is used for each case's results. An optimized model is selected as a best model, which shows better kinematic performances compared to the basis of the pre-existing model.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1395-1403
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• 2016

In recent years, researches of security threats reported that various types of social engineering attack were frequently observed. In this paper, we propose secure keypad scheme for mobile devices. In our scheme, every edge of keypad is linked each other, and it looks like a sphere. With this keypad, users input their password using pre-selected grid pointer. Because of circulation of the keypad layout, even though the attacker snatch the user password typing motion through the human eyes or motion capture devices, attacker do not estimate the original password. Moreover, without the information of grid pointer position, the attacker do not acquire original password. Therefore, our scheme is resistant to password guessing attack.

• The Journal of Korean Society for School & Community Health Education
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• v.1 no.1
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• pp.1-9
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• 2000

The purpose of this study were to assess the effect on health promotion behavior of health instruction in elementary school and to provide a basis of school health education. Subjects of this study were random sampled 80 students for control group in elementary 6th grade students. the treatment group systematically studied five sphere instruction: individual hygiene, disease prevention, first-aid & safety, oral health, health & nutrition in two hours a week, from April 20, till July 10. Each group was pre-tested and post-tested by health behavior promotion questionnaire. The conclusions as follows; 1. Compare analysis of control group and treatment group in the pre-test according to health condition of children were no significant difference physical health condition, health anxiety, disease-absent(P>.05). 2. Health promotion behaviors in the post-test according to concern quotient significantly correlated with individual hygiene(r=.249, P<.05), disease prevention(r=.477, P<.01), oral health(r=.228, P<.05), health & nutrition(r=.323, P<.01) in the treatment group, on the contrary the disease prevention, first-aid & safety, oral health, health & nutrition(P>.05). 3. The difference of health promotion behavior within & between group were as follow; 1) The difference of individual health hygiene with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(treatment group: $3.965{\pm}.568$, control group: $3.645{\pm}.573$). 2) The difference of disease prevention with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group : $3.475{\pm}.619$, c group: $3.964{\pm}.600$). 3) The difference of first-aid & safety with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group : $3.700{\pm}.466$, c group: $4.140{\pm}.545$). 4) The difference of oral health with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group: $3.163{\pm}.665$, c group: $3.753{\pm}.544$). 5) The difference of health & nutrition with in the treatment group was significant in pre-post test, the comparison of the two groups was significant difference in post-test(t group : $3.255{\pm}.515$, c group: $3.698{\pm}.558$).

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.4
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• pp.306-310
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• 2002

In this paper, we realized a system that converts the Korean alphabet (Hangul) images, which are in any domain that is formed by the finger movement on the Hangul document, to the editable characters and then outputs them to the word editor. The domain of hand is separated from the sphere of document in the pre-process step of image. The centroid point of hand is drawn by the maximum circular movement method. After the system recognizes the hand with the circular pattern vector algorithm, finds out the position of finger by the distance spectrum and then draws out the sphere of selected character image by the finger movement to divide the characters into character units by applying the histogram between the Hangul characters. We standardized the characters of various sizes. We used the circular pattern vector algorithm that grafts on the fuzzy inference to divert the character images of the domain, which user wants, to the editable characters by comparing the characteristic vectors between the standard pattern character and the inputted character and by recognizing the character.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.205-211
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• 2002

The purpose of this paper is 1) to extract managerial factor into each cell which is classified by the characteristic grill of new products 2) to construct a management model of new product development for korean companies. For this purpose, the characteristic grill of new products is classified by which is market/technology sphere. Moreover the focus of this analysis is on examination of success/failure factors, which have an important effect upon new product success or failure. The variables for this study were selected from literature survey and pre-interview was implemented specially. The subject of study was project leaders of electronics industry where have taken the leading part in product development activities in Korean manufacturing industries. Enquete survey was conducted in each firm and project managers were asked to respond. Conclusion of this study based on many significant results gained by the various multi-variate analysis are summarized as follows. First, it can he noted that success/failure factors are different by each classified model and characteristic grill of a new product. Second, it has been identified that the important factors of success products were technical & management support and market ability, the important factor of failure product were lacking in ability of technical development and R&D management system construction. This paper presents some useful guidelines in strategic and managerial aspects for development of new products. Concurrently, the model of this study should be a great practical approach for application of actual affairs.

• Journal of Information Science Theory and Practice
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• v.2 no.2
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• pp.6-15
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• 2014

Initial based disambiguation of author names is a common data pre-processing step in bibliometrics. It is widely accepted that this procedure can introduce errors into network data and any subsequent analytical results. What is not sufficiently understood is the precise impact of this step on the data and findings. We present an empirical answer to this question by comparing the impact of two commonly used initial based disambiguation methods against a reasonable proxy for ground truth data. We use DBLP, a database covering major journals and conferences in computer science and information science, as a source. We find that initial based disambiguation induces strong distortions in network metrics on the graph and node level: Authors become embedded in ties for which there is no empirical support, thus increasing their sphere of influence and diversity of involvement. Consequently, networks generated with initial-based disambiguation are more coherent and interconnected than the actual underlying networks, and individual authors appear to be more productive and more strongly embedded than they actually are.

• Medical Lasers
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• v.10 no.4
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• pp.229-237
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• 2021

Background and Objectives To assess the effectiveness of overnight orthokeratology (OK) in myopia using a new contact lens design over a one-month wearing period. Materials and Methods Participants were required to have myopia between -3.00 and -7.50D and astigmatism ≤ 2.00 D to participate in the study. The participants underwent OK with the White OK lens^® (Interojo, Pyungtek, Korea), which has a 6-curve lens design. Participants were assessed at weeks 1, 2, and 4 using slit-lamp bio-microscopy, and tested for refraction, uncorrected distance visual acuity, and corneal topography. Success was defined as achieving a Logarithm of the Minimum Angle of Resolution (logMAR) ≤ 0.1. Results A total of 46 eligible subjects with a mean age of 23.11 ± 7.89 years were recruited. Baseline logMAR was 1.18 ± 0.30 and a consistent decrease in logMAR was observed from week 1 to week 4. The success rate was 95.35% at week 4. The mean sphere significantly decreased from a mean pre-fitting value of -4.58 ± 1.28 D to a mean value of -0.65 ± 0.69 D at week 4 (p < 0.0001). Statistically significant corneal flattening was detected during keratometry at week 4. Conclusion Overnight OK with the White OK lens is effective for the correction of moderate and high myopia with astigmatism over a one-month wearing period.

• 한국항공우주법학회:학술대회논문집
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• 2008.05a
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• pp.219-231
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• 2008

" Analyzing on an object in the sphere of domestic law with the method of international law" has been already on the horizon in international law. For the lawyers of international law and space law, it is quite natural that they utilize the method of international law, whatever objects they may choice. The reason is that the characteristic of international law do not depend upon object in itself, but depend upon method in itself. The object of this paper is the idea of Peaceful Use(IPU or PU) in Japanese Space Policy. The method to be applied to this analysis is the international law's interpretation theory on legal principles, i.e., the method of international law. One of the aims of this paper is to explain critically the need of review on IPU in Japanese Space Policy; in particular with respect to the positive reconstruction of IPU through historical analyzing on the transfiguration and the mere shell of the Post-War Japanese Pacifism(PJP) as the starting point of IPU The historical process of the transfiguration and the mere shell is as followed .i.e.," from the ultranationalism in the pre-war Japan to PJP in the post-war Japan, from PJP to IPU, and from IPU to IPU's regression. In particular with respect to the interpretation theory, the meaning of the teleological, aims and objects school's approach on the interpretation of legal principles(P) has been emphasized. The reason is that the promising development of IPU will be realized by cooperating with the interpretation theory on P in international law. At the end of the beginning, I'd like to quote K. Marx's thesis in order to make the positions and missions the lawyers of international law and space clear. It is as follows, i.e.," THE PHILOSOPHERS HAVE ONLY INTERPRETED THE WORLD IN VARIOUS WAYS - THE POINT, HOWEVER IS TO CHANGE IT.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.1
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• pp.169-188
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• 2008

Analyzing on an object in the sphere of domestic law with the method of international law has been already on the horizon in international law. For the lawyers of international law and space law, it is quite natural that they utilize the method of international law, whatever objects they may choice. The reason is that the characteristic of international law do not depend upon object in itself, but depend upon method in itself. The object of this paper is the idea of Peaceful Use(IPU or PU) in Japanese Space Policy. The method to be applied to this analysis is the international law's interpretation theory on legal principles, i.e., the method of international law. One of the aims of this paper is to explain critically the need of review on IPU in Japanese Space Policy; in particular with respect to the positive reconstruction of IPU through historical analyzing on the transfiguration and the mere shell of the Post-War Japanese Pacifism(PJP) as the starting point of IPU. The historical process of the transfiguration and the mere shell is as followed, i.e., "from the ultra-nationalism in the pre-war Japan to PJP in the post-war Japan, from PJP to IPU, and from IPU to IPU's regression. In particular with respect to the interpretation theory, the meaning of the teleological, aims and objects school's approach on the interpretation of legal principles(P) has been emphasized. The reason is that the promising development of IPU will be realized by cooperating with the interpretation theory on P in international law. At the end of the beginning, I'd like to quote K. Marx's thesis in order to make the positions and missions the lawyers of international law and space clear. It is as follows, i.e., "THE PHILOSOPHERS HAVE ONLY INTERPRETED THE WORLD IN VARIOUS WAYS - THE POINT, HOWEVER IS TO CHANGE IT.