• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.155-163
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• 2008

Experimental study has been performed in order to investigate the behavior of RC beams strengthened with externally bonded post-tensioned CFRP (Carbon Fiber Reinforced Polymer) strips. Specimens consist of 9 small-scaled specimens with the different post-tensioning level as a main test parameter. A control specimen and specimens with simply bonded CFRP strips have been manufactured to compare the structural performances of prestressed system. From the test results, it was observed that the specimens strengthened with simply bonded CFRP strips showed debonding failure below 50% of CFRP tensile strength due to premature debonding. On the other hand, all the specimens strengthened with post- tensioned CFRP strips reached the rupture strength of the CFRP strip. The cracking and yielding loads were also increased proportionally to the post-tensioning level, but the ultimate loads were nearly equal regardless of the post-tensioning level.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.147-154
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• 2008

Experimental study has been performed in order to investigate the behavior of RC beams strengthened with externally unbonded post-tensioned CFRP (Carbon Fiber Reinforced Polymer) strips using embedded or stud-type plate anchorages. Total 10 small-scaled specimens were manufactured with the different post-tensioning level and types of mechanical anchorage as a main test parameter. A control specimen and specimens with simply bonded CFRP strips were included to compare the structural performances of each system. From the test results, it was observed that the specimens strengthened with simply bonded CFRP strips showed debonding failure below 50% of CFRP tensile strength due to premature debonding. On the other hand, all the specimens strengthened with post- tensioned unbonded CFRP strips reached the rupture strength of the CFRP strip. Also, it was observed that the specimens with stud-type anchorage have equivalent strengthening performance compared with embedded-type anchorage.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.108-113
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• 2018

Researches on strengthening and rehabilitation methods are being widely conducted due to the deterioration of existing concrete structures. Use of externally bonded Carbon Fiber Reinforced Polymers (CFRP) strips for the rehabilitation is a cost-effective and time-saving method. Generally, the CFRP layout for the shear strengthening was a uni-directional layout. Many researches have focused on the variables of the uni-directional CFRP layout such as the amount of material, angle, and spacing. Pilot tests indicated that the effective confinement of the concrete member can be provided with the bi-directional CFRP layout than the uni-directional layout. Therefore, the test was carried out after the uni- and bi-directional strengthening work using the same amount of CFRP material. CFRP anchors were installed to prevent unexpected premature CFRP delamination failure before reaching CFRP fracture strain. The effectiveness of the CFRP anchor and bi-directional CFRP layout for shear strengthening was verified based on the principal tensile strain contours.

• Fire Science and Engineering
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• v.21 no.2 s.66
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• pp.87-97
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• 2007

This study is to investigate the problems of procurement circumstance of the current fire service funds and to suggest the alternatives for procuring the fire service funds for dealing with increasing demand on the fire service in the local autonomous era. The results are as the followings. First, most fire service officers see the procurement circumstances as premature stage and perceive the necessity of the improvement of this condition. In particular, the officers at the fire center recognize this problem as an urgent question than the officers at the front fire branches. In addition, as for the alternatives of the procurement of fire service funds, both groups prefer the long term plan to the short term plan, and show positive responses to the National Emergency Management Agency and central government as the entity to raise fire funds. As for the alternatives to improve financial system, both groups show the most positive responses on the way to increase the current common facilities tax. As for the specific procurement alternatives of fire funds, both groups agree the alternative to increase common facilities tax mostly, and to the next they agree the alternative to insecure fire funds by restructuring current financial system and by establishing fire service hospital and fire equipment maintenance center.

• Journal of Korea Game Society
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• v.17 no.2
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• pp.145-154
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• 2017

In the age of low fertility and aging society, youth suicide is not the problem of a certain class but it should be recognized as an urgent and important social problem to be solved by our society. We aim to support the training of youth gatekeeper who can acquire the right attitude and understanding of suicide for adolescents, detect premature suicide signs of peer friends and link them to specialized institutions. In this paper, we propose a scenario based learning program that is linked to the concrete situation that the young people can sympathize with and a serious educational game of visual novel type that encourages participation of youth. We expect that the proposed serious game will improve the accessibility of educational facilities and youths through smart devices.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.450-457
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• 1998

The $Papillon-Lef\`{e}vre$ Syndrome(PLS), a disease with autosomal recessive inheritance, is characterized by diffuse hyperkeratosis of the palms and soles, mostly prepubertal periodontitis and premature loss of primary and permanent dentition. The etiology of the destruction of periodontal tissues has not been completely clarified. In recent years, two main factors are suggested to be responsible for tooth loss ; firstly, the presence of gram negative microorganisms in the periodontal pockets of the patients. The other factor suggested is cellular deficiency in chemotaxic and phagocytic function of neutrophylic granulocytes. Resent data suggestes that mechanical debridement in conjunction with antibiotic therapy may be successful in periodontal management of $Papillon-Lef\`{e}vre$ Syndrome, particularly if administered early. In this study, a $Papillon-Lef\`{e}vre$ Syndrome patient was studied clinically, radiologically, histopathologically and microbiologically. 5 years female patient with gingival swelling and destruction of periodontal structure on the whole dentition were examined and palmar and plantar hyperkeratosis were can be seen. On microbiological analysis, Actinobacillus actino-mycetemcomitans was performed. Concurrently, the children recieved extraction of maxillary anterior teeth and construction of removable prosthetis. The combination of professional oral hygiene care and antibiotic therapy improved the dermatologic and periodontal condition.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.13-18
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• 2007

Eruption disturbance is an abnormal state of eruption that occurs over a broad chronologic age range. There are many factors that influence eruption such as premature loss of primary teeth, supernumerary tooth, local disease, tongue, lip, mastication muscle and trauma. The purpose of this study was to determine the prevalence, patterns and tooth position that have eruption disturbance in children in Seoul, Korea. The subjects were 8,010 new patients who visited the department of Pediatric dentistry of Seoul National University Dental Hospital in 2004-2005. Clinical and radiographic records of the patients were reviewed by the primary investigator who is a pediatric dentist. Notable eruption disturbances included delayed eruption, early eruption and ectopic eruption and the prevalence of eruption disturbance was 8.79%.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.129-137
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• 2012

The queen-bee genetic algorithm that we made by mimicking of the reproduction of queen-bee has considerably improved the performances of genetic algorithm. However, since we used only one queen-bee in the queen-bee genetic algorithm, a problem that individuals of genetic algorithm were driven to one place where the queen-bee existed occurred. This made the performances of the queen-bee genetic algorithm degrade. In order to solve this problem, we introduce a multiple queen-bee evolution method by employing another queen-bee whose fitness is the most significantly increased than its parents as well as the original queen-bee that is the best individual in a generation. This multiple queen-bee evolution makes the probability of falling into local optimum areas decrease and allows the individuals to easily get out of the local optimum areas even if the individuals fall into a local optimum area. This results in increasing the performances of the genetic algorithm. Experimental results with four function optimization problems showed that the performances of the proposed method were better than those of the existing method in the most cases.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.39-47
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• 2011

Ergezinger's method, one of the layer-by-layer algorithms used for multilyer perceptrons, consists of an output node and can make premature saturations in the output's weight because of using linear least squared method in the output layer. These saturations are obstacles to learning time and covergence. Therefore, this paper expands Ergezinger's method to be able to use an output vector instead of an output node and introduces a learning rate to improve learning time and convergence. The learning rate is a variable rate that reflects the correlation coefficient between new weight and previous weight while updating hidden's weight. To compare the proposed method with Ergezinger's method, we tested iris recognition and nonlinear approximation. It was found that the proposed method showed better results than Ergezinger's method in learning convergence. In the CPU time considering correlation coefficient computation, the proposed method saved about 35% time than the previous method.

• Journal of the Korea Society of Computer and Information
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• v.23 no.6
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• pp.51-58
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• 2018

This study was conducted to investigate the relationship between drinking, smoking, meat intake, and exercise. The participants were 1,060 males and females who voluntarily responded to the survey by visiting the health promotion booth at the H Festival held in C city in 2014. Research data were collected in interview form using questionnaires on alcohol use, smoking, exercise, and meat intake. The data were analyzed by descriptive analysis, cross tabulation analysis, multinominal logistic regression after stratification of gender using the SPSS 24 program. The results of the study are as follows: Smokers had a significantly higher frequency of drinking ($x^2=163.33$, p<.001) than non-smokers. Meat intake was high when alcohol use was high ($x^2=35.13$, p<.001). The risk rates for smoking, meat consumption, and exercise related to alcohol use are as follows. The smoking was higher as the frequency of drinking increased. For men, smoking OR(odd ratio) was 6.26 (p=.001) and for women, smoking risk OR was 16.82 (p=.002). Meats intake showed a higher OR as the alcohol use increased. The OR of almost daily ingestion of meat at frequent drinking days was 4.40 (p=.002) for males and 4.52(p=.009) for females. As the frequency of drinking increased, the OR of days of exercise tended to decrease. In men, the OR was 0.36 (p=.003), the lowest in the probability of exercising more than 5 days when drinking high. In the case of women drinking less than once a week, the OR was 0.43 (p=.027), which was the lowest for exercise for 5 days or more. In conclusion, the higher the frequency of drinking, the higher the smoking and meat intake, and the less exercise. If drinking, smoking, and meat intake are high but there is a lack of exercise, a chronic disease can occur and cause premature death unless there is a change in the new health behavior. The results of this study suggest researches to understand the motives related to alcohol abstinence, smoking cessation, dietary control and exercise, and to develop programs.