• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.3
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• pp.1-17
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• 2022

Accurate analysis of the causes of metro rail traffic congestion provides a means of addressing issues arising from metro rail traffic congestion in metropolitan areas. Currently, congestion analysis based on counting, weight detection, CCTVs, and mobile Wi-Fi is limited by poor accuracies or because studies have been restricted to single routes and trains. In this study, a train congestion analysis model was used that includes the transfer and multi-path behavior of metro passengers and train operation plans for metropolitan urban railroads. Analysis accuracy was improved by considering traffic patterns in which passengers must wait for next trains due to overcrowding. The model updates train crowding levels every 10 minutes, provides information to potential passengers, and thus, is expected to increase the social benefits provided by the Seoul metropolitan subway

• The korean journal of orthodontics
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• v.18 no.2
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• pp.407-420
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• 1988

The primary objective of this study was to make the prediction percentile tabulation of the sum of mesiodistal widths of the unerupted permanent canines and premolars derived from the sum of mesiodistal widths of the erupted permanent incisors in normal and crowding groups. Crowding group consisted of 85 pairs of dental casts (42 males and 43 females) with more than 4mm of crowding in anteriors. Normal group consisted of 109 pairs of dental casts (65 males and 44 females) with less than 1mm of spacing or crowding in anteriors. The mesiodistal crown diameters of permanent teeth were measured from the dental casts using the sliding calipers (Mitutoyo Co., Japan). From the study, the obtained results were as follows: There were not significant differences between male and female in both groups on the basis of the ratios between the sum of mesiodistal widths of incisors and the sum of mesiodistal widths of canines and premolars. There was not significant difference between two groups on the basis of the ratio between the sum of mesiodistal widths of mandibular incisors and the sum of mesiodistal widths of mandibular canines and premolars and was significant differences between two groups on the basis of the ratio between the sum of mesiodistal widths of mandibular incisors and the sum of mesiodistal widths of maxillary canines and premolars. There was significant difference between two groups on the basis of the ratio between the sum of mesiodistal widths of maxillary incisors and the sum of mesiodistal widths of mandibular canines and premolars. There was significant difference between two groups on the basis of the ratio between the sum of mesiodistal widths of maxillary incisors and the sum of mesiodistal widths of maxillary canines and premolars. The percentile prediction tabulations were made in an attempt to predict the sum of mesiodistal widths of the unerupted permanent canines and premolars derived from the sum of mesiodistal widths of the erupted permanent mandibular incisors in each group. The percentile prediction tabulations were made in an attempt to predict the sum of mesiodistal widths of the unerupted permanent canines and premolars derived from the sum of mesiodistal widths of the erupted permanent maxillary incisors in each group.

• The korean journal of orthodontics
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• v.33 no.1 s.96
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• pp.21-29
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• 2003

Recent developments in software technology have made it possible to create a virtual three-dimensional model of the dental arches from digitally scanned casts of a patient's dentition. This modelmay then be manipulated with software to produce stages of tooth movement from the initial malocclusion to the final desired occlusion. A sterolithograghic model is made for each stage of tooth movement which is the basis for construction of a series of clear and thin overlay appliances. These appliances are worn full time by the patient to move the teeth according to the programmed stages of movement. Malocclusions involving mild to moderate crowding and space closure have been proven to be successfully treated with this appliance. Experience with this appliance has demonstrated excellent patient compliance with less discomfort, improved esthetics and oral hygiene control, when compared with fixed orthodontic appliances. Orthodontic treatment with this appliance is a potentially useful alternative approach to fixed appliances for treatment of a variety of malocclusions in patients with fully erupted permanent teeth.

• Journal of Technologic Dentistry
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• v.35 no.3
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• pp.231-242
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• 2013

Purpose: The study is to discover the relationship between malocclusion, which is known to cause temporomandibular disorder, and temporomandibular disorder and is aimed at college students who have retained their natural teeth. Methods: The study was aimed at 500 college students at two colleges located in Gyeongsangbuk-do and Daegu metropolitan city and survey research was conducted in order to discover any relationship between malocclusion and temporomandibular disorder. After excluding copies with insincere answers or errors out of the 500 copies of the questionnaire, the study used a total of 435 copies (87%) for research and analysis. Results: Females showed a prevalence of temporomandibular joint clicking and temporomandibular joint pain, and students who had crowding showed a high prevalence of temporomandibular joint pain, temporomandibular joint clicking, and trismus. Students whose occlusal condition was not good demonstrated a high prevalence of temporomandibular joint pain, temporomandibular joint clicking, and trismus. Students who had maxillary protrusion showed a prevalence of temporomandibular joint clicking and trimus, whereas students who had mandibular protrusion showed a high prevalence of temporomandibular joint clicking. Conclusion: Students whose dental condition was crowding and students whose occlusal condition was not good exhibited a high prevalence of three types of symptoms of temporomandibular disorder. Meanwhile student who had maxillary protrusion showed a high prevalence of temporomandibular joint clicking and trismus, while students who had mandibular protrusion showed a prevalence of temporomandibular joint clicking.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.1
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• pp.19-23
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• 2014

For the application of light-emitting diodes (LEDs) for general illumination, the development of high power LEDs chips became more essential. For these reasons, recently, modified vertical LEDs have been developed to meet various requirements such as better heat dissipation, higher light extraction and less cost of production. In this research, we investigate the effect of Size and Array of N-GaN contact on operation voltage with new structured padless vertical LED. We changed the size and array of N-electrodes and investigated how they affect the operation voltage of LEDs. We simulated the current crowding and expected operation voltage for different N-contact structures with commercial LED simulator. Also, we fabricated the padless vertical LED chips and measured the electrical property. From the simulation, we could know that the larger size and denser array of n-electrodes could make operation voltage decrease. These results are well in accordance with those measured values of real padless vertical LED chips.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.601-608
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• 1996

Robinow syndrome or fetal face syndrome is a rare inherited disorder characterized by short stature, mesomelic brachymelia, hypoplastic genitalia, and a typical facial appearence ("fetal face") with frontal bossing, hypertelorism, ear abnormalities, a short upturned nose, long philtrum, micrognathia, and macrocephaly. Intraoral features have included quite a few dental cavities, crowding, hypoplastic uvula, cleft lip or/and cleft palate, gingival hyperplasia, alveolar hyperplasia, enamel hypoplasia, delayed eruption, and congenital missing of the permanent teeth. We report on a 10 years old girl with Robinow syndrome. The patient had most of the typical anomalies of the syndrome and negative family history but, in addition, had mental retardation, hearing loss, and serous otitis media. Intraoral findings included dental cavities, crowding, hypoplastic uvula, repaired cleft palate, and mouth breathing. Dental treatment and V-tube insertion(by dept. of ENT) were performed under general anesthesia. In all cases of Robinow syndrome, thorough evaluation and united treatments with medical specialists should be performed.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.89-96
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• 2021

This study is aimed to establish the direction of orthodontic treatment by analyzing the differences in the dental arch development due to the cause of short stature. Dental diagnostic tests were conducted on patients who were diagnosed with short stature. Idiopathic short statured children were classified through the paired sampling based on the age and gender of a short statured children with growth hormone shortage. Control groups were classified using same method as above, after selecting candidates with an arch length of less than 3mm and malocclusion. In conclusion, short statured children with growth hormone shortage or idiopathic had the higher rate of crowding and the small value of overbite compared to normal children. Therefore orthodontic treatment for short statured children needs treatment plan included evaluation for Arch length discrepancy to treat a crowding early. This study will provide important data for successful orthodontic treatment according to the characteristics of dental occlusion of short statured children.

• Journal of dental hygiene science
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• v.6 no.1
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• pp.29-34
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• 2006

This study was undertaken to compare the tooth and arch size between crowding patient and normal subjects. Two group of dental casts were selected on the basis of crowding patients and normal subjects. One group, consisting of 40 pair of dental casts(20 male and 20 female), exhibited noncrowded dentitions. A second group, consisting of 40 pairs of dental cast(21 male and 21 female), exhibited remarkably crowding need for orthodontic treatment. Tooth width measurements were made with a sliding digital caliper with Vernier scale neared 0.01 mm. Mean, standard deviation, T-test of the following parameters were used to compare two group : individual mesiodistal crown widths, arch width and arch length. The following result were obtained. In the mesiodistal crown widths, normal subjects had generalized larger teeth than Wheeler's results(human tooth size index), except for maxillary central incisor, maxillary 2nd premolar, mandibular canine, and mandibular 1st molar. In the orthodontic patients with crowded dentitions, the mesiodistal tooth crown widths were generalized larger teeth than noncrowded normal subjects. In the arch width and arch length, the crowded dentition group had smaller arch width and arch length than the normal group.

• The Journal of the Korea Contents Association
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• v.7 no.10
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• pp.321-329
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• 2007

The form of travel has been changing to dynamic, experience and family. Festivals are popular, specially the historic culture festivals, whose themes are a history event, a time and the people, are preferred to families because they give visitors opportunities of education and experience. Evaluation of festivals is important that it diagnoses the problems and enhancement One of the evaluation methods, Importance-Performance Analysis is useful which it is easy to find priority with visual matrix without complex statistical technique and a technical terminology. This research used IPA to evaluate The Yeoncheon Jeongok Paleolithic Festival which is one of the popular historic culture festivals. From the result 'unique food', 'rest facility', 'other convenience facility', 'hygiene', 'crowding' were included in selected to 'concentrate' territory of the IPA matrix. Therefor the festival manager should put his efforts to develop unique food, build more rest and other convenience facilities, enhance hygiene, and lowered crowding.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.56-61
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• 2011

Cornelia de Lange syndrome(CdLS) is a well-described multiple malformation syndrome typically involving proportionate small stature, developmental delay, specific facial features, major malformations, and behavioral abnormalities. Dental issues include micrognathia, crowding of teeth, small teeth, absent teeth, poor oral hygiene, and periodontal disease. We present a case of CdLS in a 10-year-old girl. Micrognathia, crowding of teeth, and bifid uvula are the characteristic features of this case. Dental treatments for this child including preventive and restorative procedures were performed under outpatient general anesthesia.