• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.531-536
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• 2004

In fracture treatment with external fixators, the inter-fragmentary movements at the fracture site affect the fracture healing process, and these movements are highly related to the stiffness of external fixation systems. Therefore, in order to provide the optimal fracture healing at the fracture site, it is essential to understand the relationship between the stiffness and the system configurations in external fixation system. In this study we investigated the influences of system configuration parameters on the stiffness in the finite element analysis of an external fixation system of a long bone. The system alignment, the geometric and the material non-linearity of the pin, the joint stiffness and the callus formation were considered in the finite element model. In the first, the system stiffness of the developed finite element model was compared with the experiment data for model validation. The consideration of the joint stiffness and nonlinearity of the model improved the system stiffness results. The joint stiffness, the non-alignment of the system decreased the system stiffness while the callus formation increased the system stiffness. The present results provided the biomechanical basis of rational guidelines for design improvements of external fixators and pre-op. planning to maximize the system stiffness in fracture surgery.

• Archives of design research
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• v.15 no.3
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• pp.15-28
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• 2002

The purpose of this research is to identify the concrete imagery terms that characterize Korean cultural identity and to express Korean feelings and images through those words. We classified the selected imagery terms into the elements of design, the principles of design, abstraction, expression and function. As a result, new aspects of the Korean Image are as follows. 1, It recognized that the colors representing the Korean image are not only achromatic but also splendid. 2. Noble images with common images have taken up a large part of Korean traditional image. 3. Pleasant images as well as sad images should be presented as a new perspective to express Korean cultural identity. 4. Indirect image rather than direct image appears frequently, while positive/active image appears frequently. Since this image accounts for a large portion of Korean present image it cannot be overlooked as Korean traditional Image. 5. Korean traditional architecture is expressed as functional and rational. Up until now, representative imagery terms about Korean cultural identity appear to be positive and active and we know that Korean feelings and images are implying more variety to the image generally recognized at this time. Therefore, if today's various information technology, and values are compared and the continuity and changes of designs are appropriately combined above Korean cultural identity with these results, this will provide an essential direction for the development of global Korean designs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.936-944
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• 2019

Submarines, which have been called an invisible force, are strategic underwater weapon systems that perform missions such as anti-surface warfare, anti-submarine warfare, and high payoff target strikes with the advantage of underwater covertness. A submarine should be able to withstand the hydrostatic pressure of the deep sea. In this respect, the submarine pressure hull, as the main structural system to resist the external pressure corresponding to the submerged depth, should ensure the survivability from hazards and threats such as leakage, fires, shock, explosion, etc. To do this, the initial scantling of the submarine pressure hull must be calculated appropriately in the concept design phase. The shape of the aft transition ring varies according to its connection with the submarine aft end conical structure, pressure hull cylindrical part, and non-pressure hull of the submarine; the design of the aft transition ring should not only take into account stress flow and connectivity but also the cost increase due to the increased man-hours of its complex geometry. Therefore, trade-off studies based on the four different shapes of the aft transition ring are carried out considering both the review of the structural strength through nonlinear finite element analysis (FEA) and economic feasibility by reviewing the estimations of the manufacturing working days and material costs. Finally, the most rational structural aft transition ring shape for a submarine amongst four reviewed types was proposed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.4
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• pp.905-917
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• 2018

The sovereign state has the right to engage in self-defense or war with the approval of the Security Council when it receives an invasion of territory from a foreign country. War is conducted under the principle of the necessity and proportionality of self-defense. In case of cyber attack, proportional countermeasure must be made through attack means and effect analysis, and cyber weapons need to be classified for this purpose. Therefore, this study aims to provide a rational and legitimate response according to the necessity and proportionality of the self - defense right by suggesting definition and classification criteria of cyber weapons. In this study, cyber weapons were defined as "means of collecting, attacking, and protecting information using cyber technology in the cyber space according to military objectives. Based on existing weapon systems and public cyber weapons cases, cyber weapons were classified as (1) cyber weapons for information gathering, (2) cyber weapons for attack, and (3) cyber weapons for protection. We suggest the considerations for applying the proportional response according to this functional classification. In order to guarantee the principle of proportionality to cyber attacks in the future, the classification study based on the cyber weapon effect should be conducted. This study has conducted an exploratory study on the classification of cyber clusters which constitutes one axis of the proportionality principle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.653-664
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• 2011

In this study, I collected materials through the survey whose object is 573 students of technical high schools and 512 students of academic high schools in Seoul and Kyunggi areas, for examining dangerous factors and protective factors which influence on school resilience in technical high schools. The studying results are as followed. First, as the result of analyzing correlation between school resilience and dangerous factor, the higher dangerous factor was, the lower school resilience was. Second, as the result verifying the effects of dangerous factor on school resilience, discrimination of teacher, delinquency bond and anti-sociality made an effect on students in technical high schools and discrimination of teacher, delinquency bond and depression made an effect on students in academic high schools. Third, as the result analyzing correlation between school resilience and protective factor, the higher protective factor was, the higher school resilience was. Forth, as the result verifying the effects of protective factor on school resilience, support of teacher, democratic atmosphere of school, sense of responsibility, family cohesion, self-worth, rational supporting attitude made an effort on students in technical high schools and support of teacher, democratic atmosphere of school, sense of responsibility and family cohesion made an effect on students in academic high schools. Fifth, as the result analyzing the difference between dangerous factor and protective factor according to grade of school and standard of school resilience, there was an interaction in variables of anti-sociality, depression, delinquency bond and self-worth.

• Journal of Elementary Mathematics Education in Korea
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• v.13 no.2
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• pp.211-229
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• 2009

The purpose of this study is analysis of to investigate relation proportion problem of mathematics textbooks of 7th curriculum to proportional reasoning(relative thinking, unitizing, partitioning, ratio sense, quantitative and change, rational number) of Lamon's proposal at sixth grade students. For this study, I develop two test papers; one is for proportion problem of mathematics textbooks test paper and the other is for proportional reasoning test paper which is devided in 6 by Lamon. I test it with 2 group of sixth graders who lived in different region. After that I analysis their correlation. The result of this study is following. At proportion problem of mathematics textbooks test, the mean score is 68.7 point and the score of this test is lower than that of another regular tests. The percentage of correct answers is high if the problem can be solved by proportional expression and the expression is in constant proportion. But the percentage of correct answers is low, if it is hard to student to know that the problem can be expressed with proportional expression and the expression is not in constant proportion. At proportion reasoning test, the highest percentage of correct answers is 73.7% at ratio sense province and the lowest percentage of that is 16.2% at quantitative and change province between 6 province. The Pearson correlation analysis shows that proportion problem of mathematics textbooks test and proportion reasoning test has correlation in 5% significance level between them. It means that if a student can solve more proportion problem of mathematics textbooks then he can solve more proportional reasoning problem, and he have same ability in reverse order. In detail, the problem solving ability level difference between students are small if they met similar problem in mathematics text book, and if they didn't met similar problem before then the differences are getting bigger.

• Journal of Educational Research in Mathematics
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• v.14 no.4
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• pp.367-385
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• 2004

This study intends to compare the way of introducing fractions in elementary mathematics textbooks of south and those of north Korea. After thorough investigations of the seven differences were identified. First, the mathematics textbooks of south Korea use concrete materials like apples when they introduce equal partition context, while those of north Korea do not use that kind of concrete materials. Second, in the textbooks of south Korea, equal partition of discrete quantities are considered after continuous ones are introduced. This is different from the approach of the north Korean text-books in which both quantities are regarded at the same time. Third, the quantitative fraction which refers to the rational number with unit of measure at the end of it, is hardly used in the textbooks of south. However, the textbooks of north Korea use it as the main representations of fractions. Fourth, in the textbooks of south Korea, vanous activities related to fractions are more emphasized, while in the textbooks of north Korea, various meanings of fractions textbooks from south and north Korea focused on the ways of introducing partition approach and equivalence relation as operational schemes of fractions, the following play an important role before defining fraction. Fifth, the textbooks of south Korea introduce equivalent fractions with number one using number bar, and do not consider the reason why that sort of fractions are regarded. On the contrary, the textbooks of north Korea introduce structural equivalence relation by using various contexts including length measure and volume measure situations. Sixth, whereas real-life contexts are provided for introducing equivalent fractions in the textbooks of south Korea, visual explanations and mathematical representations play an important role in the textbooks of north Korea. Seventh, the means of finding equivalent fractions are provided directly in the textbooks of south Korea, whereas the nature of equivalent fractions and the methods of making equivalent fractions are considered in the textbooks of north Korea.

• Archives of design research
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• v.12 no.4
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• pp.89-98
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• 1999

The application of tool which has grown rapidly by the age was used for the product development, however as today the computer digitalization has been fixed to the necessary process in every factory-made mass production, making the sensitive desire of designer the digitalization through systematic, rational information database building from the planning level of product to the final mass production in such a environment change. It should satisfy a variety of needs of consumer. The enterprise that hopes to get a winner in the present age brought in computer with useful tool to process information efficiently. The computer has displayed much more excellent computation ability than human to come up to their expectation and the growth of electronic technology was possible to make the computer's high-efficiency, economy and integration. No matter what we have a good economy and integration. No matter what we have a good information there is no meaning unless we are able to use it' so we should take it out by the our need. Therefore, this paper observes a future-oriented possibility of computer & Telecommunication in information society, information-oriented design environment and the trends of minimal and integrated computer. We will improve the designer's ability to develop a novel product that have the diversification of them using application, aiming at computer utilization and image identification design strategy of product in the age of network telecommunication.

• Archives of design research
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• v.18 no.3 s.61
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• pp.45-54
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• 2005

Visual messages are fundamental elements for performing communication and indicate the signs which are delivered from the communicator to the communicatee via channels, Generally, we can classify visual messages into two groups; linguistic factors which are rational and deliver abstract concepts and unlinguistic factors which are mental and can be expressed concretely. Especially, web site with receivers' low attention and concentration need images which can attract their attention to visual messages. That is, web site is a medium which allows us to feel visual and emotional experiences. We can call it a standard of sign systems which are consisted of various styles of digital texts. The main purpose of this study lies in that we'll analyze how homepage introductory page as one of the forms of digital text conduces a meaning action to the receivers and that we'll apprehend the structures of images and different types of signs via a semiotic approach and analyze the underlying meaning of the messages. In order to survey the structures of images we'll look into the attitude toward perceiving messages by using semantic differential method which has been developed mostly by Osgood and analyze the visual images by adopting sign types of Fuss. As the signification is created by combining signs, it is significant that we'll analyze the meaning of sings between the transmitters and receivers from the semiotic viewpoint and study the signification systems.

• Archives of design research
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• v.19 no.2 s.64
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• pp.129-138
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• 2006

Design securing a dominant position currently in the global market has shown inherent culture of each country, i.d. national disposition. For instancess, there are Scandinavia emphasizing humanism, America adopting pragmatism, Germany reflecting the rational principle, Spain reflecting the daily an, Italian design being rationalism and impressionism. The members of society shall be under the control of the already formed social-cultural value and character. So culture shall restrict the internal manner of social behaviour and apply pressure to the action of main body. Also culture shall be under the control of social environment and each culture shall be materialized as per the disposition of the members of society. Now korean design has been attracted lots of interests and attention from global market because it is excellent in the aspect of application capability for new technology and also suggests the image of design produced through them. Now Korean design shall run side by side the application for formative element to be recognized by technical design as well as korean identity. So dear definition for national and cultural disposition shall be required to korean design education and design development. These prescribed efforts shall be a shortcut for globalization of korean design.