• Journal of The Korean Association For Science Education
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• v.32 no.3
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• pp.415-427
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• 2012

In this study, we conducted preliminary survey, diagnostic test and in-depth interview in order to study Korean pre-service chemistry teachers' understanding on entropy and investigate how Korean pre-service chemistry teachers deal with the natural phenomenon which is related to entropy conceptions. Firstly, as a result of the preliminary survey, it was found that pre-service chemistry teachers strongly recognized entropy as the degree of disorder. Secondly, the diagnostic test showed pre-service chemistry teachers were mostly confused about whether the entropy of the universe increases during a spontaneous change, and they had a tendency to interpret the natural phenomenon related to entropy change as the change of disorder. Finally, during in-depth interview, after we explained entropy change in all diagnostic test questions with the concept of microstate, pre-service chemistry teachers revealed a better understanding about entropy. Through this research, pre-service chemistry teachers had an opportunity to reflect on their deficiencies of entropy conceptions, which will ultimately help students to approach the concept of entropy more correctly.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.514-517
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• 2006

Nonseismic designed RC frame have a possibility of shear failure because of deficiencies of reinforcing details. To model the shear failure in numerical analysis, shear strength degradation models which include Moehle's and ATC 40 are compared and applied to push-over analysis. For numerical analysis, three storied building frame is selected and designed according to Korean Concrete Design Code(2003). From the numerical analysis, it is pointed out that there may be great difference in lateral drift capacity if a different shear strength model is used. And the capacity can be severely underestimated if the restraining model of plastic rotation of ATC 40 is used, compared to the use of shear spring for shear degradation.

• The Journal of the Korean dental association
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• v.22 no.12 s.187
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• pp.1067-1073
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• 1984

In the treatment of functional orthodontic problems, timing is not an issue. All orthodontists start as soon as the condition is recognized. However, there is an active dialogue concerning treatment timing for structure problems. The major points in contention center around the operator's ability is to control the growth of the facial bones and to maintain post-treatment tooth position through the maturation period (especially when this position was gained by techniques involving arch expansion or distal driving of posterior segments). Factors taken into account to determine the best time of orthodontic treatment include diagnosis, interception, growth rate, patient cooperation, eruptive state and treatment period. With those exceptions of all functional problems, mild dental discrepancies and skeletal deficiencies with a predictably excellent growth potential (early treatment), the period immediately following the eruption of the permanent second molars is the period during which most orthodontic treatment should be initiated. At this time the full volume of tooth substances is present, the individual growth pattern in well established, there are sufficient teeth to receive nearly any type of appliances and the patient can easily tolerate the wearing of appliances.

• The Journal of the Korean dental association
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• v.51 no.6
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• pp.313-321
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• 2013

The most common orthodontic methods of treating mandibular transverse deficiencies is extractions, interdental stripping, and other dento-alveolar compensation but it can not addressesd about skeletal problem This study assessed the treatment outcomes after surgically assisted rapid tooth orthodontics using the symphysis osteotomy and dentoalveolar distraction osteogenesis technique. The applications of distraction osteogenesis in mandibular widening, by symphysis osteotomy, has emerged as a definitive, predictable and better stability. The most important factors in mandibular widening is performed with simple surgical technique and devices. As a results, these techniques are very useful and effective in cases of difficult tooth movement in adult orthodontics transverse problems There were few intraoperative or postoperative complications and were not clinically significant.

• Journal of Information Technology Applications and Management
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• v.15 no.3
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• pp.61-77
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• 2008

Research results show (1) there are two dimensions characterizing Korean IS practitioners : 'project -operation' and 'product-orientation-strategic-orientation', (2) there are two distinctive and main career paths of Korean IS practitioners : generalists who support using information systems in the context of operation and specialists who are engaged in software development or improvement projects, and (3) Korean IS practitioners are experiencing serious and pervasive knowledge and skill deficiencies. Research results also provide clear evidence that Korean universities fail to provide eligible entry-level software developers and that the shortage of eligible entry-level software developers distorts both IS specialists' careers and knowledge and skill requirements for them.

• Research in Mathematical Education
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• v.17 no.3
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• pp.169-180
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• 2013

Communicating about mathematics is an essential component in learning mathematics and is a key standard for successful learning in a mathematics classroom using stories and storytelling as a catalyst to mathematics instruction. This, however, can make learning math for students with language deficiencies since they are working toward mastering both basic language proficiency as well as the specialized language needed for mathematics. This is a particular concern because the number of students of multicultural families is rapidly increasing. In this paper, we discuss the challenges and complexities of language-deficient students learning math in a classroom where communication is a key standard for successful learning, and suggest implications for teaching, by presenting an USA elementrny teacher's scaffolding to make reading and solving word problems less intimidating for her language learner students as well as native speaking students.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.265-270
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• 2003

When designing an engine part the designer has to choose the proper material and to define the dimensions of the part. in the most rudimentary case he has available as guidelines the collective experience from similar applications. The performance of the part is tested on occasion of the trial runs for the full system, and possibly occurring deficiencies are corrected until a satisfactory usable life and safety of operation is achieved. This procedure is time consuming and costly, and the learning effect is minimal. These requirements have to be condensed into characteristic values ameanable to computation. Since testing and computation are complementary we have to look at the currently existing mathematical models for engine bearing performance.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.sup1
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• pp.117-126
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• 2008

Trace elements compose a very small portion of the body, however they have a variety of essential functions. Various diseases are caused by trace element deficiencies, and sometimes they can be fatal. Long-term TPN is a risk factor of trace element deficiency, and trace elements need to be checked regularly while receiving TPN. It is important to provide sufficient requirements of trace elements regarding the clinical features and the problems of trace element excess or deficiency. Moreover extensive studies to establish the efficiency of examining human hair and nails, recent method to determine the trace elements, are required.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.442-445
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• 1997

A challenging activity in the manufacturing industry is to perform in real time the continuous monitoring of the process state, the situation assessment and identification of the problem on line and diagnosis of the cause and importance of the problem if he process does not work properly. This paper describes LAT(Ladder Analysis Tool) system for fault tree generation to improving the fault diagnosis of CNC machine tools. The system consists of 4 steps which can automatically ladder analysis from ladder diagram to two diagnosis function models. The two diagnostic models based on he ladder diagram is switching function model and step switching function model. This system tries to overcome diagnosis deficiencies present machine tool.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3411-3420
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• 2014

Deficiencies in wear and frost resistance as well as mechanical strength constitute the main causes of equipment failure under the harsh climatic conditions of the Earth's polar regions. To improve the properties of the materials used in this equipment, nanoparticle composites have been prepared from clays such as kaolinite, hectorite, and montmorillonite in combination with polytetrafluoroethylene (PTFE) or ultrahigh molecular weight polyethylene (UHMWPE). A number of techniques have been proposed to disperse silicate particles in PTFE or UHMWPE polymer matrices, and several successful processes have even been widely applied. Polymer nanocomposites that exhibit enhanced mechanical and thermal properties are promising materials for replacing metals and glass in the equipment intended for Arctic use. In this article, we will review PTFE- and UHMWPE-based layered silicate nanocomposites.