• Journal of the Korean earth science society
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• 제23권4호
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• pp.324-333
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• 2002

Recent studies have indicated that boys show better scientific achievements compared to those of girls. It is also a general conception that boys would be better than girls in terms of scientific creative performances and potential, although there have been few studies to support the general opinion. As the gifted education in Korea is progressing very rapidly, the importance of understanding the creative characteristics of gifted boys and girls has been increased. In the present study, we have compared and analyzed three different measures of creativity utilizing 135 gifted students (77 boys and 58 girls) to provide an empirical evidence for the different degrees of creative performances between gifted boys and girls. The instruments used to measure diverse aspects of creativity include the Torrance Test of Creativity (TTCT), the Test of Creative Problem-solving and Finding in Science (CPFS), and the Creative Behavioral Checklist in Science(CBCS). The results of the study indicate that girls, rather than boys, showed better creative performances, demonstrating moderately higher average scores on the three creative measures used in the study. The results are in contrast to people's general conception that boys would be more creative than girls. Implications of the study in connection with identification and educational practices for gifted education program have been discussed.

• Journal of the Korean Society of Food Science and Nutrition
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• 제38권11호
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• pp.1625-1632
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• 2009

This study investigated consumer awareness on imported food safety management. The questionnaire explored status for confirmation as imported foods, consideration factors when imported foods were marketed, ways for finding imported food safety information, people responsible for problems in imported foods safety management, and imported food safety management items. Answers to 1065 questionnaires were analyzed using S-Plus 8.0. The principal results were as follows: 35.7% of respondents always confirmed whether it was imported food. The most important imported foods marketed is children food. 55.1% of respondents think inspectors have responsibility for problems of imported foods safety management. The most important factor for improvement of safety is reinforcement of quarantine. The providing of restricted information only after security problem occurs was the reason for non-satisfaction of safety information.

• Culinary science and hospitality research
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• 제15권1호
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• pp.209-224
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• 2009

The objective of this study is to find out how well-being influences consumer behavior of dining-out. Based on this objective, this study covers plans for improving marketing strategies, which contributes to menu development and purchase behavior of consumers. This study consists of two parts : a research based on the review of the literature and empirical study methods. The finding of the study would also be valuable for the development of management of advertising strategies to be implemented in the foodservice industry. Based on the survey statistics, Program SPSS 12.0 and Amos 5.0 were used in order to look into a casual relationship among group units. The findings of the demonstration analysis are as follows. Most of previous research regarding well-being in local study is psychological well-being dealt with individual health and psychological satisfaction. On the other hand, social well-being is likely to focus on public relation rather than private concerns. The fact that the term 'well-being' have not been definitely defined yet was a problem in research. Also, well-being should not be recognized as a temporary trend but as a general trend. Therefore, it is necessary to understand consumer behavior which is changeable as the circumstance of the foodservice industry changes.

• Survey Research
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• 제4권2호
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• pp.63-86
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• 2003

The objective of this study was to investigate the existence of starting point bias in the bidding game contingent valuation elicitation technique when determining willingness to pay (WTP) for improving the qualify of running water in Seoul and its vicinity. Of all existing contingent techniques, the bidding game most closely mimics the normal price taking behavior in local markets. Three different starting points (low, medium and high) were used to determine WTP and the existence of starting point bias in the meanwhile respectively. The respondents were randomly assigned to the three different starting point groups in order to ensure homogeneity, so that any variation seen in WTP could be attributed to the starting point effects. And a pretested interviewer-administered questionnaire used to elicit WTP. Non-parametric test and the logit model were used to analyze the data for evidence of starting point bias. In this instance, the high starting point group had a high WTP, and low starting point group had a low WTP. This means there exist starting point bias in estimating WTP by bidding game in this instance. This finding might signal that people may actually be making up their minds on the maximum amount they are willing to pay for running water service as a bidding iterating is going on and is influenced by the starting point used in the bidding game. The problem of slaking point bias can be avoided if the respondent is asked directly for the maximum WTP without payment cards or a bidding game. But such a question is perceived as being very difficult to answer and this leads to problems of non-response and being unrealistic.

• Tuberculosis and Respiratory Diseases
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• 제40권4호
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• pp.442-448
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• 1993

Foreign body aspiration, although not an uncommon problem in children, is unusual in adults and is overlooked as a cause of airway obstruction. Small foreign bodies that lodge in the peripheral airway are often asymptomatic initially and can result in respiratory symptoms several years later. Especially in the cases of otherwise healthy subjects, even though manifested overt respiratory symptoms, diagnosis can be delayed due to lack of history of aspiration or unnoticed aspiration. A 57-year-old male was admitted to Yonsei University College of Medicine Severance hospital due to left upper chest pain for five months. on the past history he had been diagnosed as bronchiectasis about 20 years ago. He showed radiologically bead-like bronchostenosis and a calcific density protruding into the lumen of left upper lobar bronchus. Bronchoscopically broncholith was revealed with the finding of endobronchial obstruction of each upper and lingular division of left upper lobar bronchus due to mucoid impaction and surrounding inflammed bronchial mucosa. The preoperative diagnosis was broncholithiasis due to chronic inflammatory process. Lung perfusion scan shows absence of perfusion in left upper lobe. So left upper lobectomy was performed. But from the pathologic specimen an incisor tooth was emerged. Later a history of tooth extraction thirty years ago at dental clinic was found. We report a case of bronchial obstruction due to occult aspiration of a tooth with a review of the literatures.

• Journal of the Korean Institute of Intelligent Systems
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• 제21권1호
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• pp.36-41
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• 2011

Configuration space(C-space) including configuration obstacle(C-obstacle) is one of the most important concepts in mobile robot path planning. Using C-space and C-obstacles, the robot with different shapes and moving mechanisms can be considered as a point in the C-space. And, as a result, the collision-free path for the robot can be easily achieved. To make C-space including C-obstacle, many researchers used circular approximation method for the efficient caluculation time. This method can help us to save our time by approximating the shape of a robot as the minimum sized circle which can cover all the area of robot. But, by using the circle larger than the robot, more space are considered as the part of robot and, as a result, some obstacles which are very near each other may be considered as a combined one obstacle. To solve this problem, multi-level configuration space is proposed by this paper. This multi-level method also use the circular approximation method as the initial step. But, after finding the initial path, it will check how many obstacles are combined. And then, for each combined obstacle, more accurate C-space generation will be continued. To check the efficiency of the proposed algorithm, time for c-space generation are compared with the well-known accurate C-space generation method using various types of robot shape.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제18권6호
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• pp.1283-1293
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• 2014

In ubiquitous environment, data are changing rapidly and new data is coming as times passes. And sometimes all of the past data will be lost if there is not sufficient space in memory. Therefore, there is a need to make rules and combine it with new data not to lose all the past data or to deal with large amounts of data. In making decision trees and extracting rules, the weight of each of rules is generally determined by the total number of the class at leaf. The computational problem of finding a minimum finite state acceptor compatible with given data is NP-hard. We assume that rules extracted are not correct and may have the loss of some information. Because of this precondition. this paper presents a new approach for refining rules. It controls their weight of rules of previous knowledge or data. In solving rule refinement, this paper tries to make a variety of rules with pruning method with majority and minority properties, control weight of each of rules and observe the change of performances. In this paper, the decision tree classifier with extended data expression having static weight is used for this proposed study. Experiments show that performances conducted with a new policy of refining rules may get better.

• Korean Chemical Engineering Research
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• 제46권4호
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• pp.739-746
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• 2008

The aim of this study is finding the optimal design parameters and the optimal operation variables of a reactive distillation column. Different from steady state optimization, dynamic optimization makes it possible considering operation ability as well as design problems at process design step. For performing dynamic optimization, dynamic simulation should be done first. If dynamic simulation is already finished, dynamic optimization can be performed with less effort than that of dynamic simulation.Reactive distillation systems involving reaction and separation in a single unit have the potential to reduce capital and operating costs, particularly when reaction have conversion constraint or when azeotropes exist making conventional separation difficult and expensive. This study here present work on the continuous distillation process, the homogeneous catalyzed esterification of methanol and acetic acid, the synthesis of methyl acetate. Based on an equilibrium stage model of a reactive distillation column a dynamic optimization problem was formulated and solved. And the results were verified by performing dynamic simulation and showing the variation of conversion and purity as the variation of the operation variables. As the results of dynamic optimization, this study found optimal feed ratio, reflux ratio and reboiler duty of this system. And as this study applied it to dynamic simulations the dynamic characteristics of a reactive distillation column are showed under optimal operating condition.

• Biomedical Science Letters
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• 제5권2호
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• pp.191-200
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• 1999

In recent years continuously increasing number of tuberculosis (TB) cases due to the emergence of strains with multidrug resistance and AIDS is a significant global health problem. Therefore, more rapid and reliable diagnosis of TB may be one of the most urgent needs in efforts to eradicate the disease. The present study was designed to compare and assess the diagnostic values and efficiencies between the conventional methods (X-ray, AFB stain and culture) and PCR for pulmonary TB on 171 cases. Chest X-ray finding and clinical features revealed that 39 (22.8%) of 171 sputum specimens were pulmonary TB cases. The statistical data were taken on the basis of the definitive diagnosis: In X-ray, overall sensitivity, specificity, efficiency and false positive and false negative incidence was respectively 69.2%, 87.1％, 83.0%, 12.9%, and 30.8％； 79.5%, 95.5%, 91.8%,4.6％ and 20.5％ in AFB-stain; 56.4%, 99.2%,89.5%, 0.8% and 43.6% in culture; 82.1%, 96.2%, 93.0%, 3.8% and 17.9% in PCR. PCR got a highest sensitivity and efficiency as well as a lowest false negative incidence. Culture had a highest specificity with a lowest false positive incidence. These results imply that PCR assay is fast, sensitive and efficient method for diagnosis of pulmonary TB. However, combined use of the conventional methods with thorough quality control may offer more opportunities for detecting Mycobacterium tuberculosis and diagnosting TB although they have some limits.

• The korean journal of orthodontics
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• 제30권4호
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• pp.453-465
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• 2000

The purpose of this study was to investigate the change of mechanical properties, surface topography and frictional force of various nickel titanium wires after recycling. Three types of nickel-titanium wires and one type of stainless steel wire were divided to three groups: as-received condition(T0:control group), treated in artificial saliva for four weeks(T1) and autoclaved after being treated in artificial saliva(T2). Some changes were observed for the selected mechanical properties in tensile test, surface topography by means of SEM and 3D profilogram, and frictional coefficient. The findings suggest that: 1. Nickel-titanium wires demonstrated no statistically significant differences in maximum tensile strength, elongation rate and modulus of elasticity, but stainless steel wire demonstrated statistically significant differences in maximum tensile strength, elongation rate and modulus of elasticity between the groups(p<0.05). 2. NiTi, Optimalloy, Stainless Steel wires demonstrated increased pitting and corrosion in SEM finding. 3. Recycled NiTi, Optimalloy and stainless steel wires demonstrated significantly greater surface roughness(Ra and Rq) through 3D profilogram when compared with the control wires(p<0.05), but Sentalloy didn't demonstrate significant difference. 4. Recycled NiTi, Optimalloy and stainless steel wires demonstrated significantly greater maximum frictional coefficient when compared with the control wires(p<0.05), but Sentalloy didn't demonstrate significant difference The changes of surface roughness and frictional coefficient in NiTi and Optimalloy had no clinical implication. Consequently recycled nickel titanium wires demonstrated no clinical problem in tensile properties, surface topography and frictional coefficient.