• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.1
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• pp.25-34
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• 2016

Treatment of missing mandibular 4 incisors is often thought to be easier then other place during surgical and prothetic procedure. But clinicians encounter unexpected difficulties such as restricted implant site due to mesio-distal width of mandibular incisors, limited space as a result of crowing and mesial drift, esthetic problem after severe alveolar bone resorption, and difficulties of provisionalization Through cases, possible treatment options for missing mandibular incisors would be discussed. Treatment options for missing mandibular 4 incisors Place narrow type implant or one body mini implant on exact tooth position when there is no bone resorption Regular size implant on interseptal bone area when there is severe bone resorption Consider using resin bonded bridge(resin retained bridge/resin bonded fixed partial denture) as a tentative prosthesis when patient resists extracting remaining incisors with poor prognosis.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.265-266
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• 2015

A search for luminous white dwarfs (WDs) in several nearby Galactic globular clusters (GCs) was carried out using the deep and homogeneous photometric catalog of Galactic GCs taken with the ACS/WFC aboard the Hubble Space Telescope (HST) by Sarajedini et al. and Anderson et al- It resulted in the identification of luminous WD candidates in the GCs M13 (NGC 6205) and M22 (NGC 6656). The purpose of the present study is to identify luminous WDs in the deep and homogeneous V versus V - I color-magnitude diagrams (CMDs) of several nearby Galactic GCs taken with the ACS/WFC aboard the HST. Using photometric data for the GCs M13 and M22 that are now in the public domain, the V versus V - I CMDs of the GCs M13 and M22 were constructed. Many spurious detections in the CMDs were removed using the photometric quality parameters qfit(V) and qfit(I), and a radial restriction was applied to the CMDs to remove the central stars with higher photometric errors due to central crowding. From each resultant V versus V - I CMD of the GCs M13 and M22, a dozen or so luminous WD candidates were identified. They were confirmed as stellar objects in the accompanying ACS/WFC images and their positions in the CMDs were in the bright part of the DA WD cooling curve. Therefore, the luminous WD candidates in the GCs M13 and M22 seem to be true luminous WDs, and spectroscopic observations are needed to confirm their true identity.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.630-635
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• 2004

The etiology of mesiodens is unknown but the most widely accepted theory is the hyperactivity of the dental lamina. Complications of mesiodens are delayed or prevented eruption of maxillary central incisors, displacement or rotation of permanent teeth, crowding of affected region, abnormal diastema or permanent space closure, dilaceration or abnormal root development of permanent teeth, primordial or follicular cyst formation, root resorption of adjacent teeth, eruption into nasal cavity. If mesiodens rotate the maxillary central incisors, space deficiency is not common and relapse is very common. So overcorrection is needed. To prevent the rotational relapse, early treatment, overcorrection, long retention period, properly formed proximal surface, use of coupled force, and surgical techniques have been suggested. The authors present two cases, whose chief complain were severely rotated maxillary incisors by mesiodens, treated by orthodontic and surgical technique and showed good results.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.93-104
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• 2000

Orthodontic treatment in conjunction with second-molar extraction has been a controversial issue among orthodontists over many decades. The aim of this study was to investigate the treatment effects of upper second molar extraction cases. The sample included 19 upper second molar extraction orthodontic cases(ten Angle's Class I's and nine Class II's, average age=13Y 6M) cared at Kyung-Hee University Department of Orthodontics. Lateral cephalometric radiographs were taken before and immediately after treatment. Seventy-nine points were digitized on each cephalogram and 38 cephalometric parameters were computed comprising 22 angular measurements, 13 linear measurements, and 3 facial proportions. The data obtained from each malocclusion group were analyzed by paired t-test. The statistical results disclosed that there was no significant change in skeletal pattern after treatment except for that accountable by growth while there was statistically significant change in dentoalveolar and soft tissue patterns. There were no significant changes in Bjork sum, posterior facial height /anterior facial height and lower anterior facial height /anterior facial height. No significant changes in anteroposterior position of maxilla and palatal plane were manifested. Although facial axis and lower facial height was slightly increased and the mandible was rotated backward and downward, there was no remarkable change in the mandibular plane. There were statistically significant changes in distal movement of upper first molar, molar key correction and overjet reduction while there was no change in the occlusal plane. The upper lip was slightly retracted simultaneously with slight increase in nasolabial angle. These results signify that distalization of upper dentition with the second molar extraction does change occlusal relationship without gross modifications in the craniofacial skeletal configurationson. Henceforth the second molar extracted would be recommended to treat severe anterior crowding and protrusion with minor skeletal discrepancy.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.508-516
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• 2010

Hallasan National Park is facing dramatic increase of visitors since no entrance fee charge effected in January of 2007 and it has created a concern about appropriate use levels. The overall objective of this study is development of the carrying capacity indicators management program using indicator and standard based on visitor experience and resource protection (VERP) model. The result of delphi survey identified eight potential indicators of resource and experiential conditions, including quality of valley water, visitor counts, trail impacts, crowding etc. Also, Data were also gathered to help provide an empirical foundation for setting standards for these indicator variables. The carrying capacity indicators management program based on VERP model estimates sustainability of national park and analyze scientifically change about resources and visitor's behavior. Also, it systematically manage and use united data, it supports operation accomplishment respected rational decision.

• Journal of the Korean Institute of Landscape Architecture
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• v.14 no.2
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• pp.43-68
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• 1986

It is necessary that children's actual activities in the playgrounds should be analyzed for the study on the children's playgrounds. The purpose of this study is to establish the design principles for the improvement of the children\`s playgrounds in apartment complex by means of the various methods ; behavior mapping, questionaires and photo simulations. For the purpose of data collection, children are divided into three groups-infants(0 to 4 years), young children(pre ; 5 to 8 years, post ; 9 to 11 years), teenagers(7.2 to 14 years). The study results are as follows; 1) Analysis of behavior mapping : (a) Approximately 70 percent of the children observed stayed in the playground less than 20 minutes. (b) Playing time for each play apparatus was less than 5 minutes. (c) As a result of the observation, the duration time in the attic was 1 hour or more (d) The swing was the most frequently used apparatus as children's first and last choice. (e) Most of the users were young children(46.5%). 2) Analysis of questionaires : (a) Children considered that the existing playgrounds were lack of shadows and the play apparatuses are not interesting. (b) They felt danger and crowding at the multi-used wooden apparatus. 3) Suggestions for the playground design : It is necessary that the playgrounds are divided into the infants, the young children's and the teenagers'playground. (a) The infants'playground needs about 50 square meters and needs to be located in the apartment court. (b) The young children's playground needs about 330 to 660 square meters and needs to be located adjacent to the pedestrian road. (c) The teenagers'playground needs about 660 to 1000 square meters, which is needed for various ball games.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.4
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• pp.15-27
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• 1994

주거환경에서 거주자의 '시각만족(residents' satisfaction with visual appearance)은 더 큰 추상적 개념인 '주거만족'(residents' housing satisfaction)과의 밀접한 인과적 관련(Francescato et. al., 1979) 때문뿐만 아니라 인간 기본 욕구 중의 하나인 미적 욕구의 충족과 관련되어 있다는 점(Chin, 1991)에서도 중요시 되어야 할 이론적 개념이다. 본 연구에서는 거주자의 시각만족을 종속지표로 보고, 다양한 영향 가설변수들과의 인과 적 관련도를 경로분석(path analysis)을 통해 검증하고 있으며, 어떤 변수 가 어떤 이유(경로)로 또는 얼마만한 크기로 거주자의 시각만족에 영향을 주는 가가 중점적으로 토의된다. 한국의 6개 대단위 주거단지로부터 다단 계표집 방법과 설문면담 방법을 통해 646명의 응답이 수거되었다. 분석의 첫 단계로써, 다수의 설문문항을 본 연구의 가설 변수로 집약하기 위한 요 인분석(factor analysis)이 사용되었고, 요인 분석으로부터 추출된 변수들간 의 인과적 관련도를 검증하기 위해 최종적으로 경로분석이 사용되었다. 본 연구의 결과를 요약해 볼 때, 본 연구의 가설 변수 대부분이 최종 종속변 수인 거주자의 '시각만족'에 유의한 인과 영향을 보이는 것으로 나타났으 며, 구체적으로 '시각적 무질서'(visual disorder), '시각적 단조로움'(visual monotony), '단지 과밀감'(development crowding) 등이 부정적 영향을, '시 각적 매력'(visual attractiveness)과 '인근 자연녹지의 존재'(presence of nearby natural environment)등이 긍정적 영향을 미치는 것으로 파악되었 다. 그 외에도 '옥외공간이용 편리'(outdoor or recreation convenience)와 ' 이웃만족'(satisfaction with neighbors), 그리고 '주거환경 유형'(building type, building arrangement type)등도 유의한 인과적 관련을 보이므로써, 기존 문헌들이 제시하고 있는 것보다 훨씬 다양한 변수들이 다양한 경로를 통해 거주자 시각만족의 영향인자가 될 수 있는 가능성을 제시하고 있다. 가설 변수의 하나인 '길찾기의 난이 정도'(difficulty of way-finding)와 종 속변수간에 유의한 관련도가 나타나지 않은 이유로 길찾기 변수가 '시각만 족'보다는 거주자의 '안전만족'(safety)과 관련된 변수일 가능성도 아울러 지적되었다. 본 연구의 결과로부터, 주거 계획 및 설계분야 그리고 추후 관 련 연구 분야를 위한 여러 제안들이 제시되었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6276-6281
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• 2014

Genetic Algorithms (GAs) are efficient methods for search and optimization problems. On the other hand, there are some problems associated with the premature convergence to local optima of the multimodal function, which has multi peaks. The problem is related to the lack of genetic diversity of the population to cover the search spaces sufficiently. A sharing and crowding method were introduced. This paper proposed strategies to improve the convergence speed and the convergence to the global optimum for solving the multimodal optimization function. These strategies included the random generated sub-population that were well-distributed and spread widely through search spaces. The results of the simulation verified the effects of the proposed method.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.543-553
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• 2015

This study analyzed that the impact of the bus use environment on users' stress in each step of bus use, from accessing to leaving to transfer, in the city of Daejeon. For this, we collected the stress data from 300 users using personal interviews at the bus stops and on-board bus. Also, we used factor analysis and structural equation model method for analysis of the impact of external and internal bus environments on stress of users. The results of this study showed that the highest stress impact factor was an onboard factor(${\beta}=.416$) including 'density and crowding', 'no seat to seat' and 'low ride comfort and safe'. The next stress impact factor was transfer factor including 'insufficient transfer information', 'lack of connectivity of bus and subway' and 'uncomfort transfer route'. From the above, we recommend that bus policies need to focus on not the supplier but users and also, this user based policy need to be more specified considering the characteristics of various users such as females, the elderly, irregular users, and so on.

• Journal of the Korean Arthroscopy Society
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• v.14 no.3
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• pp.192-195
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• 2010

Subcoracoid impingement resulting from abnormal contact between the anterosuperior humerus and the anterior coracoacromial arch represents an uncommon source of anterior shoulder pain. Certain operative procedures can also alter the relationship between the coracoid and the lesser tuberosity, leading to impingement of the interventing soft tissue, including the subscapularis and the bursa. We describe an unique case of subcoracoid impingement with the tear of subscapularis tendon after the internal fixation of the fractured coracoid process with cannulated screw due to crowding of the coracohumeral space. Arthroscopic removal of the screw and repair of the subscapularis in our patient resulted in successful resolution of his symptoms. Although subcoracoid impingement is a rare cause of shoulder pain, failure to diagnose and treat this condition may represent a significant cause of failed shoulder surgery.