• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.8 s.350
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• pp.35-43
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• 2006

In the paper, we propose a new method for power optimization that uses path balancing based on stochastic estimation of glitch in Statistical Static Timing Analysis (SSTA). The proposed method estimates the probability of glitch occurrence using tightness probability of each node in timing graph. In addition, we propose efficient gate sizing technique for glitch reduction using accurate calculation of sizing effect in delay considering probability of glitch occurrence. The efficiency of proposed method has been verified on ISCAS85 benchmark circuits with $0.16{\mu}m$ model parameters. Experimental results show up to 8.6% of accuracy improvement in glitch estimation and 9.5% of optimization improvement.

• The korean journal of orthodontics
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• v.40 no.1
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• pp.50-60
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• 2010

The purpose of this article was to evaluate the effects of a new upper molar distalization system, the Frog Appliance, on dentofacial structures in a Class II, division 1 patient. An 11-year-old girl was referred to our clinic for orthodontic treatment. She had a mild skeletal Class II malocclusion with Class II molar and canine relationship on both sides. The treatment plan included distalization of the upper first molars bilaterally followed by full fixed appliance therapy. For the upper molar distalization, a new system, the Frog Appliance, was constructed and applied. Lateral cephalometric radiographs were used to evaluate the treatment results. Distalization of the upper first molars was achieved in four months successfully, and Class I molar relationship was obtained. Total treatment time was 16 months. According to the results of the cephalometric evaluation, a nearly bodily distal molar movement with a slight anchorage loss was attained. In conclusion, the Frog Appliance was found to be a simple, ef ective, non-invasive, and compliance-free intraoral distalization appliance for achieving bilateral molar distalization.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.119-125
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• 2005

In the primary dentitions, the majority of dental injuries involve the anterior teeth, especially the maxillary primary central incisors. When injuries affecting primary and permanent teeth are compared, it appears that trauma to the primary dentition is usually confined to the supporting structures, i.e. luxation and exarticulation, while the largest proportion of injuries affecting the permanent dentition is represented by crown fractures. But, cases reporting trauma affecting primary molars are unusual in the literature and several reports describe fractures of posterior teeth. The main goal of this report is to describe the repositioning treatment using removable appliances to an uncommon case of lingual displacement of primary molar that happened to a 4 year 5 month-old female child.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.523-531
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• 2008

Maxillary molar distalization is a treatment approach for patients with Class II malocclusions who do not require extractions and mesial movements of mandibular molars. The pendulum appliance is effective for distalization of the maxillary molars and independent of patient cooperation. This appliance can stabilize the maxillary premolars and use the palatal rugae area as an additional anchorage. However, caution is needed to control collateral effects, including increase of lower facial height, incisor protrusion and damage to the rugae area. This article reports the cases in which maxillary molar distalization achieved by pendulum appliance resolves the space problems and corrects the molar relationships.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.438-445
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• 2020

Taurodontism is an anomaly characterized by a long and broad pulpal cavity and consumed apical location of the furcation area. This study aimed to determine the prevalence of taurodontism in deciduous molars based on digital panoramic radiographs of children. The study was performed on a sample of panoramic radiographs taken from 2,473 Korean children who visited the department of pediatric dentistry, Yonsei University Dental Hospital between Nov. 2005 and Mar. 2018. Taurodontism was mainly categorized by Daito's method. Using panoramic radiographs, taurodontism was also categorized into mesotaurodontism, hypotaurodontism, and hypertaurodontism. Mesotaurodontism was the most prevalent type. A total of 2,473 panoramic radiographs were evaluated. The prevalence of taurodontism was 5.7% in general, 51.5% in the left quadrant, 48.5% in the right quadrant, 6.3% in the maxilla, and 93.7% in the mandible. The distribution of taurodontism stratified by gender showed a higher prevalence in males. This is a comprehensive study on the prevalence of taurodontism in children using the largest sample size to date.

• Korean journal of applied entomology
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• v.34 no.2
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• pp.120-126
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• 1995

This study investigated the soil oribatid mite community at planatations of the Korean white pine, planted in different years. The soil samples $(10\times10\times5cm)$ were taken monthly from Jun 1988 to July 1989, and soil microarthropods in th sample were extracted using the Tullgren funnel for 72 hors. The diversity indices decreased at the older plantation sites with the maximum point in January and the minimum in September. The richness indices showed the maximum point in June and the minimum in may. The dominance indices increased at the older plantation and showed the maximum point in April, May, the minimum in January. The indices of aggregation of Oribatid mites species showed concentrated distribution in the average 1.9. The older plantation, the more indices increase. The seasonal variation of th indices tended to be greatest in April, August and at lowest in January. The richness indices was positively correlated with shannon-wiener, evenness indices. The dominance, aggregation indices was negatively correlated with shannon, evenness, richness indices.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.3
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• pp.257-263
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• 2015

Impacted teeth occur at higher frequencies in permanent than primary dentition. The most frequently affected teeth are the maxillary and mandibular third molars, whereas it is quite uncommon for the mandibular first molar to be impacted. Treatment methods for impacted teeth include continuous examination for independent eruption, surgical exposure, subluxation after surgical exposure, orthodontic traction, and surgical repositioning. If all of these treatments fail, tooth extraction may be considered. In the first case study, an 8-year-old boy was treated with surgical exposure, after which he was fitted with an obturator. His mandibular first molar then erupted successfully. In the second case, we treated a 12 year-old boy using orthodontic traction. This study describes children with tooth eruption disorders of the mandibular first molar in mixed dentition, and reports acceptable results regarding treatment of the impacted teeth.

• Journal of the Korean Data and Information Science Society
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• v.27 no.1
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• pp.131-142
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• 2016

Outliers in surveys can have a large effect on estimates of totals. This is especially true in business surveys where the populations are drawn are typically skewed. In this paper, we discussed the practical development and implementation of methods to identify and deal with outliers. A detection method is based on quartile method and detected outlier is processed in various ways. The study examines two versions of winsorised estimators with three different cut-off thresholds for each one. For the simulation study, four types of weight transformation function have been considered.

• Journal of the Korean GEO-environmental Society
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• v.16 no.5
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• pp.43-53
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• 2015

In this study, detection methods of outlier in various monitoring data that fit into big data category were developed and outlier detections were conducted for both artificial data and real field monitoring data. Rule-based methods applied rate of change and probability of error for monitoring data are effective to detect a large-scale short faults and constant faults having no change within a certain period. There are however, problems with misjudgement that consider the normal data with a large scale variation as outlier caused by using independent single dataset. Rule-based methods for noise faults detection have a limit to application of real monitoring data due to the problem with a choice of proper window size of data and finding of threshold for outlier judgment. A correlation analysis among different two datasets were very effective to detect localized outlier and abnormal variation for short and long-term monitoring dataset if reasonable range of training data could be selected.

• Journal of dental hygiene science
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• v.4 no.2
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• pp.55-60
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• 2004

The study was intended to investigate the job values type of freshmen's in the dental hygiene department. A total of 280 freshmen in the dental hygiene departments of the 3 universities were surveyed, and of them, finally 242 volumes of questionnaire were analyzed. Their job values were categorized through twice factor analysis. The findings were as follows. 1. Freshmen's job values in the dental hygiene department were divided into 6 categories; (1) position (2) economic reward (3) social contribution (4) accomplishment (5) ability (6) job interest. 2. Social contribution, accomplishment, ability, and job interest were categorized into internal job values, and position and economic reward were externl ones. 3. Dental hygiene freshmen's external values index (4.24) were higher than internal ones (3.86). 4. Types of job values that dental hygiene freshmen thought important were economic reward (4.39), position (4.07), ability (3.98), and social contribution (3.46).