• Journal of dental hygiene science
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• v.13 no.2
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• pp.151-157
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• 2013

The purpose of this study was to examine the toothbrush bristles' wear index and wear rate used by preschool children to provide information on the establishment of criteria for toothbrush replacement cycle for preschool children. One thousand twenty-two toothbrushes were collected from September 20 to November 16, 2012 was analyzed. The findings of the study were as follows: 1. As a result of analyzing the toothbrush wear index, 48.5% of the collected toothbrushes was above 0.400, and the average wear index was $0.421{\pm}0.239$. 2. As a result of analyzing the wear rate of the toothbrushes, score 2 and 3 accounted for 70.4%, and the average wear rate stood at $1.936{\pm}0.848$. 3. As a result of analyzing the state of toothbrush management, the most common average toothbrush replacement cycle was one or two months (63.9%). Concerning the method of toothbrush replacement, the largest group (52.7%) replied they changed toothbrushes based on the abrasivity of toothbrush bristles, and 16.7 percent did that at the request of parents. Given the above-mentioned findings of the study, preschool teachers and parents should be educated to ensure the successful management of preschool children toothbrushes. In addition, it's required to set evident criteria for the right toothbrush replacement cycle for preschool children, and how to provide oral health education in an efficient way should be considered as well.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.444-456
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• 2000

To test the shear bond strength of a new "one-bottle adhesive" system to primary dentin two commercially available one-bottle adhesives (Prime & Bond NT, Single bond) and conventional three step system(Scotchbond Multi-Purpose Plus) were included for comparison. And We observe the interfacial morphology by scanning electron microscope. 90 primary molar teeth were embedded in acrylic and buccal and lingual surface were polished to 320 grit to create standardized dentin surface for testing. After bonding of composite resin to sample surfaces according to the manufacturer s direction and 1000 times thermocycling in dwell time 30 second, Shear bond strengths of adhesives to dentin were determined using universal testing machine and analyzed by ANOVA test. Another groups of specimens were treated by hydrochloric acid to secure the resin only and those tags were evaluated under SEM for their length and forms and the morphology of the bonding sites were also observed. The result are as follows. 1. Group I(Prime & Bond NT) showed higher shear bond strength than group iI(Single Bond) and III(Scotchbond Multi Purpose Plus) but no statistically significant difference was founded between groups(p>.05). 2. Relating long resin tags of $70-120{\mu}m$ were observed in samples of all groups under SEM. We could observed hybrid layer, resin tag and many lateral branches in every group. But, we observed in group III rare lateral branched than other two group and discontinuous hybrid layer.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.260-266
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• 2010

Trauma to the primary teeth may have an effect on the successive permanent teeth. Thus, the treatment plans should be focused on safety of their permanent teeth. The degree of developmental disturbances in those permanent teeth depends upon many factors including the age of the children, developmental conditions of the affected teeth, types and severities of trauma and time interval from the moment of trauma to the initial treatment the patients received. The complications of the effected permanent teeth vary from the mild enamel hypoplasia to the premature finishing of teeth development. In this study, children whose ages were 33 months, 5 years, and 26 months presented the developmental disturbances to their permanent teeth, which resulted from the trauma to the primary teeth: the intrusion, the avulsion, and the subluxation. There showed a mild complication in the case of subluxation resulting in enamel hypoplasia, but, the more severe complication of the root dilacerations occurred in the case of intrusion. Furthermore, the 5-year-old patient whose primary dentition was near in transition period to the permanent one, the more complicated problem such as stop of root development of the permanent teeth was resulted from the avulsion. Thus, one should assume that the types of trauma and the age of the children at the moment of trauma have different effects on those successive permanent teeth. In conclusion, when the trauma that causes changes in the position of primary teeth happened, it is important to arrange an appropriate treatment procedure considering the types of trauma and the developmental conditions of the permanent teeth.

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.193-204
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• 2004

This study was conducted to evaluate both temporal and spatial dynamics of phytoplankton community and environmental parameters in a newly made reclaimed esturine lake (L. Hwaong). Monthly sampling was conducted at 4 sites covering the longest transect of longitudinal gradient of the lake from June to November, 2002. Total 5 classes 8 orders 26 families 83 genus 192 species were identified at all study sites during the study period. Phytoplankton total cell density ranged 24${\sim}$ 1,882 cells $mL^{-1}$ and highly varied both temporally and spatially. Total cell density was significantly related with salinity, pH, BOD, COD, SS, TN and TP concentration. Diatom density also was significantly correlated with salinity, SS, BOD, COD and TN concentration, Although there was spatial difference, a longtudinal gradient appeared in phytoplankton cell density, Chl-a, TN and TP concentration from the mouth of river in June and August. In conclusion, phytoplakton community structure was dominated by diatoms (Bacillariophyceae), and appeared to be largely influenced by salinity, precipitation, and nutrients during the summer and the fall.

• Applied Microscopy
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• v.32 no.2
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• pp.107-119
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• 2002

Early spermatocytes of U. unicinctus are found in cluster floating in the coelomic fluid. The spermatocytes in a cluster form a syncytium or cytoplasmic mass, but there are no indications that the cytoplasmic mass is a component of a somatic cell. This work suggested that this type of spermatogenesis can be subordinated to solitary spermatogenesis in the sense excluding structural and functional support of a somatic cell for sperm developments. The solitary spermatogenesis in U. unicinctus is different in appearances and developmental details of sperm organelles and stage distributions from that of localized spermatogenesis. The acrosomal rudiments and centrioles can be observed in the early single cells of spermatogonia and clearly disclosed in the primary spermatocyte. In the stage of secondary spermatocyte, the acrosomal precursor and the centrioles begin to move to each cytoplasmic poles. The polarities of the organelles are attained at stage of spermatids. The spermatocytes and spermatids are arranged circumferentially along the cytoplasmic mass in which some amorphological cytoplasmic components are included. The spermatids reveal to be detached from the cytoplasmic mass into coelomic fluid. It suggests that the spermatogenesis are progressed in support of coelomic fluid, and the fact take into consideration that the spermatogenic cells can be in vitro cultured without somatic cells and with supplements of coelomic fluid.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1102-1106
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• 2005

Purpose : The present study examined the etiology, management, and the difference of prognosis according to methodology of treatment in severe hyperbilirubinemia with total serum bilirubin levels of more than 25 mg/dL. Methods : Medical records of severe hyperbilirubiemia in newborns(serum level=25 mg/dL) admitted to the NICU of Samsung Medical Center between October 1994 and June 2004 were reviewed retrospectively. Infants were grouped according to methodology of treatment : Group I(phototherapy only, n=42), Group II(exchange transfusion, n=6). And In addition, we evaluated the etiology and the difference of prognosis. Results : A total of 48 documented cases of severe hyperbilirubinemia were identified. Birth weight was significantly lower in Group 2($2,852{\pm}1,085g$) compared to Group 1($3,137{\pm}437g$)(P<0.05). There were no significant differences in gestational age, sex, mode of delivery, inborn, age at presentation, and age at first examination and admission between the two study groups. Maximal bilirubin level was significantly higher in Group 2($45{\pm}16mg/dL$) compared to Group 1($29{\pm}6mg/dL$) (P<0.05). But there were no significant differences in neurologic outcome. Conclusion : Our study suggests that the present guidelines for managing hyperbilirubinemia in newborns should be effective but follow-up with the first postnatal week would be necessary for each detection and treatment in the newborn infants with high risk of severe hyperbilirubinemia.

• Cross-Cultural Studies
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• v.44
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• pp.87-121
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• 2016

Daehoon Ham's novel 'Cheongchunbo' features a studier as the main character who majored in Russian literature and admired the culture of the Soviet Union. From his viewpoint, the novel reproduces North Korean society before and after its independence from Japan. In this regard, it shows multilayered presence related to Russian culture and Soviet Russia. Such an aspect is based on the sense of sympathy that the main character has. The sense of sympathy is originated from the main character's admiration for the exoticism of Soviet culture which was forbidden during the late Japanese occupation. After Korea's independence from Japan, Russian was replaced by English. Such change also occurred in the main character's viewpoint. He underwent a change in his integrative viewpoint on Russian and Soviet under the name of Red Army. After defecting to South Korea, he began to put Russia down as a den possessed by the devil called 'communism.' In the meantime, Russia and Soviet have been separated from each other in ideological terms. The novel 'Cheongchunbo' stresses that the decisive cause of such changes is argued over trusteeship. The main character, fascinated by the presence of exotic Soviet, predicates that Soviet is a political symbol around the national division caused by the trusteeship. His change alluded to the life path of Korean authors who translated Russian literature after independence. During the Japanese occupation, Russian literature translated into Korea was a longing for forbiddance and admiration for Russia. However, the Russia presented in Daehoon Ham's novel before and after independence implies that the romantic translation has ended.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.3 no.2
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• pp.91-96
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• 2007

Cleidocranial dysplasia(CCD) is a congenital genetic disorder of skeletal and dental abnormality, which is mesodermal dysfunction influencing many tissues and organs, CCD was reported by Morand at first in 1766, And later, it was named cleidocranial dysostosis, cleidocranial dysplasia, Marie-sainton syndrome and mutational dysostosis. It is autosomal dominant disorder and there is no prevalence between man and woman. Until recent days, mutation of Runx2 in chromosome6p21 has known to be a main factor causing CCD. The specific clinical features of CCD are aplasia or hypoplasia of one or both clavicles and incomplete closing of fontanels and cranial sutures. Dental manifestations include retention of deciduous teeth, delayed eruption of permanent teeth, supernumerary teeth and cyst. Because there is no mental retardation and physical disability in CCD patients, they usually can not recognize their dental abnormality by the time of abolescence. So, after exfoliation of deciduous teeth, they usually live with edentulous status. It usually drives CCD patients to suffer from esthetic and functional problem. For this reason, CCD patients must be early diagnosed and improved in their appearance as well as masticatory function. So, surgical removal of supernumerary teeth and orthodontic eruption of the natural permanent teeth at adequate time is necessary.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.486-489
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• 2002

Construction management has been a target of the result and the index which were decided by whether the resourecs(time, cost and progress...etc) were used. but this has been serious problems in time and cost because of the shortage of storage space, the incident, lowering of efficiency for works, working impossible of between work categories and the demage of finished products. Therefore I noticed that more correct and more objective establish of data collecting system was necessary. it was through the diversification of information for exchange and communication between the construction site and participants. DVR(Digital Video Recorder) and internet technology were suggested for a solution to this problem. the collected information by DVR was divided to 3 steps as how long it used and how much it processed for improving efficiency of using and storage of information. and then it was verified through applying to cases at construction site.

• Archives of design research
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• v.20 no.1 s.69
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• pp.121-132
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• 2007

A change of social environment based on digital information technology has decreased the disparity of regional cultures by exchanging & consuming contemporary information & culture freely. After 1995, when local autonomous entity system was established, the local autonomous bodies competed with one another in developing the regional society with its' own resources, human powers & cultures, independently of the central government. In the competitive system, a local government is getting itself distinguished from each other in the cultural & regional properties, and brands the region with its unique events, public relations(PR) & development strategies. The environment for advertisement has changed rapidly under the spontaneous system of regional brand and competition, which means the changes of creative standard in the field of advertisement. An in-depth advertising creativity with induced impression & trust is one of the most important aspects of the advertisement to become persuasive to the public effectively. This demand has had public advertisements changed rapidly and the change of regional system's advertisements has started already. This study focuses on analyzing the status of Local Government's commercials on TV, and presenting an effective method for improving it.