• Journal of the Korean Society of Earth Science Education
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• v.3 no.2
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• pp.141-147
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• 2010

This study was carried out to analyze terms in primary science textbooks. The results of the research are as follows. 1. The higher-grade science textbooks use more types of categories and less definitions for terms. Only 14% of definitions for terms are showed in textbooks, and no more than 0.4~0.6 definitions shows the shortage of definitions for terms in one class content. 2. The definitions by contract, which forms 68%, was the highest in elementary science textbooks. And the dictionary definitions, which are 62%, was the highest in experiment-observation textbooks. 3. The most used type of definitions is the way which is used for a case or a indicating methods, and its rate is increasing steadily. And its rate was 76% of the whole of terms. 4. Terms used in energy field are few as compared with terms of other fields. Each field has completely different ways of defining terms and presenting content in textbooks to other fields.

• The Journal of Aerospace Industry
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• s.49
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• pp.3-40
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• 1999

In this paper, the types of airport operation are categorized four groups in context of ownership and operational management; full government ownership and operation; government ownership with privatization of selected service; government ownership and private management; private ownership and operation. The term,"Privatization" has a different definition when it is used in different contexts and cultures. In this paper, the definition of"Privatization" in the context of airport, is that the movement of an entity from the government sector to the private sector. To keep pace with the remarkable growth in the air traffic volume of passengers and cargo, more and more mega-international airports have been built or are under construction. As the air transport demand is expected to increase at an even greater rate in the 21st century, the need for new conception airport is merging to solve the current problems such as airport congestions and flight delays which will be essential factors to decide whether the competitive airports or not. Presently, we researched the type of the operational management to strengthen the competitiveness for Korea's airports. Specifically, It is focused on the government ownership with privatization of selected services. It seems to be evaluated as government ownership and private management when it is actively utilized within Korea Airport Authority's law or Inchon International Airport's public corporation law. To make more competitive airport in 21st Century, however, it is desirable to seek for the method to gradually evaluate to private ownership and operation.

• Journal of Mechanical Science and Technology
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• v.15 no.9
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• pp.1257-1267
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• 2001

For efficient mechanical system optimization, a new two-point approximation method is presented. Unlike the conventional two-point approximation methods such as TPEA, TANA, TANA-1, TANA-2 and TANA-3, this introduces the shifting level into each exponential intervening variable to avoid the lack of definition of the conventional exponential intervening variables due to zero-or negative-valued design variables. Then a new quadratic approximation whose Hessian matrix has only diagonal elements of different values is proposed in terms of these shifted exponential intervening variables. These diagonal elements are determined in a closed form that corrects the typical error in the approximate gradient of the TANA series due to the lack of definition of exponential type intervening variables and their incomplete second-order terms. Also, a correction coefficient is multiplied to the pre-determined quadratic term to match the value of approximate function with that of the previous point. Finally, in order to show the numerical performance of the proposed method, a sequential approximate optimizer is developed and applied to solve six typical design problems. These optimization results are compared with those of TANA-3. These comparisons show that the proposed method gives more efficient and reliable results than TANA-3.

• Journal of Elementary Mathematics Education in Korea
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• v.9 no.2
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• pp.137-159
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• 2005

As what exactly understands a meaning of mathematics terms, is a starting point of mathematical thinking, it plays a very important role in the mathematics learning. What understood mathematics terms which were defined here, includes not only the terms of comprising its definition, but also all of the understanding in context, situation, intention and purpose, which came to give its definition. Due to this reason, it needs to be examined how much students are correctly understanding about mathematics terms which appear in the texts, and to seek for its cause for the terms which are felt to be difficult. Accordingly, this study investigated into mathematics terms which are used for the field of geometry in the elementary school mathematics textbooks, and tried to analyze students' understanding level about each term.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.6
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• pp.429-436
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• 2019

Since the discovery of the first artificial synthetic plastic, bakelite, polymer materials have been recognized as one of the most innovative fields of research. The plastic debris that is being piled up on the earth (called abandoned plastic litters) is now being observed everywhere on Earth, becoming an increasingly serious environmental threat. The term 'microplastics', created in 2004, now refers to plastic particles that are smaller than 5 mm, including all nano-sized plastic particles. However, there is no legal regulation, and there is still a lack of comprehensive definitions that practically include microplastic size standards. In this study, we will refer to "microplastics" as the English name, and look at how to identify these microplastics and propose new definitions that focus on their size. This study is expected to contribute to the domestic consensus on scientific definitions of microplastics.

• Clinical and Experimental Pediatrics
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• v.65 no.1
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• pp.21-28
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• 2022

Crohn disease (CD) is a multifactorial inflammatory disorder that can affect all segments of the gastrointestinal (GI) tract but typically involves the ileum and/or colon. To assess patient prognosis and choose appropriate treatment, it is necessary to accurately evaluate the factors influencing poor outcomes, including disease phenotype. Pediatric CD involving the upper GI (UGI) tract has become increasingly recognized with the introduction of routine upper endoscopy with biopsies for all patients and the increased availability of accurate small bowel evaluations. Most clinical manifestations are mild and nonspecific; however, UGI involvement should not be overlooked since it can cause serious complications. Although controversy persists about the definition of upper GI involvement, aphthoid ulcers, longitudinal ulcers, a bamboo joint-like appearance, stenosis, and fistula are endoscopic findings suggestive of CD. In addition, the primary histological findings, such as focally enhanced gastritis and noncaseating granulomas, are highly suggestive of CD. The association between UGI involvement and poor prognosis of CD remains controversial. However, the unstandardized definition and absence of a validated tool for evaluating disease severity complicate the objective assessment of UGI involvement in CD. Therefore, more prospective studies are needed to provide further insight into the standardized assessment of UGI involvement and long-term prognosis of CD. Our review summarizes the findings to date in the literature as well as UGI involvement in CD and its clinical implications.

• Asia pacific journal of information systems
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• v.24 no.2
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• pp.141-189
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• 2014

As urbanization and its consequences become the issue of modern cities, the concept of Smart City comes as the solution. Though a lot of researches on the topic is done, still no clear definition is given for both: Smart City itself and the factors of a successful Smart City. While most of the literature centers the role of ICT it is not a sufficient condition for a city to become Smart; the role of intellectual capital is underestimated. Using a collection of Smart City definitions across the time and providing concrete cases, this research seeks to bridge definition gaps and creates a tool for understanding Smart Cities. Drawing on the findings of several case studies, this research derives several explanatory factors. The citizen's engagement and governance are identified as the two key success factors of Smart City Projects along with ICT and other factors as enablers. The research has purpose as follows: 1) To bridge definition gaps of the "Smart City" by defining the term "Smart City," based on existing concepts and characteristic mechanisms across times.; 2) To develop an analytical tool for Smart City success factors through Explanatory Variables.; and 3) To identify major challenges and barriers of Smart City Projects implementations and to provide recommendations and solutions, based on existing governmental initiatives and pilot projects. The research contributes to the knowledge of smart cities and ICT integration for urbanization issues solution. By applying the findings of this research at the managerial level stakeholders may benefit by getting higher efficiency of the Smart City Projects and by utilizing knowledge and values of a Smart City Projects in a prioritized way.

• Journal of Educational Research in Mathematics
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• v.19 no.3
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• pp.393-407
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• 2009

In this article the definition of similarity and its introduction in Korean middle school textbooks based on the 7th national curriculum are analysed critically. As a result four suggestions are presented. First, on the consideration that the contents related with similarity has been removed in the elementary school curriculum, the meaning of 'constant rate' needs to be understood through the rich experience of drawing enlarged/reduced figures when similarity is introduced in middle school, Second, there are two different ways in enlargement/reduction of figures and in the definition of similarity. Teachers have to keep the limitations of the two ways in mind. Third, the activity of drawing similar figures in enlarged/reduced squared paper needs to be practiced. Last, on 'the relation of similarity' which is in the definition of similarity, it has to be examined whether 'similarity' should be presented in the documents of the national curriculum as a term.

• Journal of Periodontal and Implant Science
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• v.44 no.1
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• pp.39-47
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• 2014

Purpose: Peri-implantitis, a clinical term describing the inflammatory process that affects the soft and hard tissues around an osseointegrated implant, may lead to peri-implant pocket formation and loss of supporting bone. However, this imprecise definition has resulted in a wide variation of the reported prevalence; ${\geq}10%$ of implants and 20% of patients over a 5- to 10-year period after implantation has been reported. The individual reporting of bone loss, bleeding on probing, pocket probing depth and inconsistent recording of results has led to this variation in the prevalence. Thus, a specific definition of peri-implantitis is needed. This paper describes the vast variation existing in the definition of peri-implantitis and suggests a logical way to record the degree and prevalence of the condition. The evaluation of bone loss must be made within the concept of natural physiological bony remodelling according to the initial peri-implant hard and soft tissue damage and actual definitive load of the implant. Therefore, the reason for bone loss must be determined as either a result of the individual osseous remodelling process or a response to infection. Methods: The most current Papers and Consensus of Opinion describing peri-implantitis are presented to illustrate the dilemma that periodontologists and implant surgeons are faced with when diagnosing the degree of the disease process and the necessary treatment regime that will be required. Results: The treatment of peri-implantitis should be determined by its severity. A case of advanced peri-implantitis is at risk of extreme implant exposure that results in a loss of soft tissue morphology and keratinized gingival tissue. Conclusions: Loss of bone at the implant surface may lead to loss of bone at any adjacent natural teeth or implants. Thus, if early detection of peri-implantitis has not occurred and the disease process progresses to advanced peri-implantitis, the compromised hard and soft tissues will require extensive, skill-sensitive regenerative procedures, including implantotomy, established periodontal regenerative techniques and alternative osteotomy sites.

• Journal of The Korean Association For Science Education
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• v.32 no.8
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• pp.1295-1317
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• 2012

There has been disagreement on the importance of definitions in science education. Yager (1983) believes that one crisis in science education was due to the considerable emphasis upon the learning of definitions. Hobson (2004) disagrees with physics textbooks that do not provide general definition on energy. Some textbooks explain that "there is no completely satisfactory definition of energy" or they can only "struggle to define it." In general, imprecise definitions in textbooks (Bauman, 1992) and inaccuracies in definition provided by teachers (Galili & Lehavi, 2006) may cause alternative conceptions. Besides, there are at least four challenges in defining physical concepts: precision, circularity, context and completeness in knowledge. These definitional problems that have been discussed in The Feynman Lectures, may impede the learning of physical concepts. A meta-study approach is employed to examine about five hundreds journal papers that may discuss definitions in physics, problems in defining physical concepts and how they may result in alternative conceptions. These journal papers are mainly selected from journals such as American Journal of Physics, International Journal of Science Education, Journal of Research in Science Teaching, Physics Education, The Physics Teachers, and so on. There are also comparisons of definitions with definitions from textbooks, Dictionaries of Physics, and English Dictionaries. To understand the nature of alternative conception, Lee et al. (2010) have suggested a theoretical framework to describe the learning issues by synthesizing cognitive psychology and science education approaches. Taking it a step further, this study incorporates the challenges in semantics and epistemology, proposes that there are at least four variants of alternative conceptions. We may coin the term, 'alternative definitions', to refer to the commonly available definitions, which have these four problems in defining physics concepts. Based on this study, alternative definitions may result in at least four variants of alternative conceptions. Note that these four definitional problems or challenges in definitions cannot be easily resolved. Educators should be cognizant of the four variants of alternative conceptions which can arise from alternative definitions. The concepts of alternative definitions can be useful and possibly generalized to science education and beyond.