• 치과방사선
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• 제7권1호
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• pp.5-8
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• 1977

The author has observed 906 full mouth roentgenograms in Korean young man who had the impacted and supernumerary teeth. Impacted and supernumerary teeth were analysed upon several items, such as incidences and positions in the dental arch. The result were as follows; 1. The incidences of impacted teeth were 59.05% and the ratio of upper jaw to lower one was 1:3. 2. The frequency of the supernumerary teeth were 5.52% and the ratio of maxilla to mandible was 49:1. 3. No significant differences between right and left side in both jaws, but incidence rate of the supernumerary teeth was 74% in the maxillary central incisor area. 4. The positions of impacted and supernumerary teeth were vertical and inverted shapes in maxilla, whereas horizontal and mesio-angular forms in mandible.

• 치과방사선
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• 제12권1호
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• pp.63-67
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• 1982

The author modified the Aquard 100 head holder device from Denar Co. to be adequate to the Koreans and to enhance the standardization and reproducibility of the temporomandibular joint radiographs. The results were obtained as follows; 1. The projected central ray was at an angle of 25 degrees. 2. Standardization of patients head position was obtained by means of vertical and horizontal bar which were attached to the head holder. 3. Arbitrary 3 points (A.B.C.) which were on the TMJ area of dry skull were measured for the identification of reproducibility. 4. Measured distances in dry skull were as follow; A-B, 28.0±0.25, B-C 11.9±0.25 and C-A 30.4±0.21, in closed position.

• Asian Journal of Atmospheric Environment
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• 제6권2호
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• pp.127-135
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• 2012

Urbanization has led to a reduction in green spaces and thus transformed the spatial pattern of urban land use. An increase in air temperature directly affects forest vegetation, phenology, and biodiversity in urban areas. In this paper, we analyze the changing land use patterns and urban heat distribution (UHD) in Seoul on the basis of a spatial assessment. It is necessary to monitor and assess the functions of green spaces in order to understand the changes in the green space. In addition, we estimated the influence of green space on urban temperature using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) imagery and climatic data. Results of the assessment showed that UHD differences cause differences in temperature variation and the spatial extent of temperature reducing effects due to urban green space. The ratio of urban heat area to green space cooling area increases rapidly with increasing distance from a green space boundary. This shows that urban green space plays an important role for mitigating urban heating in central areas. This study demonstrated the importance of green space by characterizing the spatiotemporal variations in temperature associated with urban green spaces.

• 대한토목학회논문집
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• 제32권1D호
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• pp.71-80
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• 2012

수도권의 기능 및 범위 확대로 인하여 광역교통수요가 급증하였고, 이러한 광역교통수요를 충족시키기 위해서는 다양한 광역대중교통 보급이 필요하다. 하지만 막대한 투자재원을 필요로 하는 광역교통시설의 설치 및 운영 관리에 대한 명확한 기준과 제도의 부족으로 중앙정부와 지방정부, 지방정부와 지방정부 사이에서 갈등이 일어나고 있는 실정이다. 본 연구에서는 수도권 광역 BRT, 광역 환승시설 등의 효율적인 설치 및 운영 관리를 위한 재원분담 모델을 개발하여 재원분담기준을 설정하고자 하였다. 이에 국내외 사례를 기반으로 광역 BRT 시설의 주요 구성요소인 광역 BRT 노선, 광역 환승시설 그리고 공영차고지의 재원분담 모형을 정립하고 정립된 재원분담모형을 적용하여 대안별 비교분석을 수행하였다.

• 한국IT서비스학회지
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• 제15권2호
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• pp.203-217
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• 2016

This paper explores the distribution of the retail coffee franchise stores in Seoul using geostatistical analyses. The fact that lots of coffee stores are concentrated in the central area-Jongno and Jung-gu and commercial area-Gangnam and Seocho shows that the size of the floating population and potential customers is one of main drivers for making decisions on the locations of new stores. Except these 4 districts, the number of stores and population exhibit a positive correlation. By extracting the information on the 6 large coffee franchises store locations, we calculate the both haversine distances between stores of the same franchise and between stores of different franchises. We then empirically test the sitting and marketing strategies of Starbucks, Ediya, and Paik-Dabang using distance distributions. Significant pairs of Starbucks stores located within 100m confirm the sitting strategy of Starbucks which opens additional stores at crossways, stations, near shopping malls or other business zones though there already exist Starbucks stores. Meanwhile considerable portion of Ediya stores are found near Starbucks stores, which coincides with the sitting strategy of Ediya. We also find that Paik-Dabang that uses the low cost strategy has its stores open relatively farther than other franchises from Starbucks stores.

• 한국농촌건축학회논문집
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• 제19권3호
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• pp.17-24
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• 2017

The aim of this study is how to understand of structural and elemental landscape image in suburban village. Nowadays, it is well known fact that suburban villages are most likely to be invaded by urbanization. Therefore, the research is focused on how the image of suburb has been changed, what patterns have been created in residential area, what are the different outcomes from different distance, and what are the changes in types of buildings, at particular village called Doojeong in Pyeongtaek city. When collecting supplemental information, elders in village have been participated in comparison of traditional and foreign. The village shows significant characteristics of such phenomenon. According to the research, there are three results. First, ironically, the structural patterns of the village is concentric as seen on urban garden, yet they do not have central function. Second, traditional homes are transformed into functional shape. The most popular roof design that takes 65 percent of whole is modernized flat roof shape. Hanok (Korean traditional house) style is disappearing. Third, due to the massive barn buildings and their monochrome, the beauty of community and architectural harmony are buried.

• 한국기록관리학회지
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• 제10권2호
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• pp.127-146
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• 2010

이제 중앙행정기관 뿐 아니라 기초자치단체에도 기록물관리 전문요원들이 다수 채용되어 체계적인 기록관리의 형태를 갖추어 가고 있다. 이 연구에서는 기초자치단체 기록관을 대상으로 한 기록관리현황을 알아보고자 하였다. 이를 위해 기록물관리 전문요원의 채용이 많이 이루어졌던 서울 경기 인천 등 수도권에 소재한 기초자치단체 기록관 중 11곳에서 2009년 9~10월 사이에 기록물관리 전문요원들과 심층면담을 시행하였다. 이를 통해 기초자치단체 기록관의 제도적 측면, 운영 관련 및 기록정보 서비스 관련 분야의 현황과 문제점을 분석해보고, 이들 각각의 분야에 대해 개선 방안을 찾아보고 제시하였다.

• 시스템엔지니어링학술지
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• 제17권2호
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• pp.122-128
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• 2021

Despite various economic crises, the domestic parcel delivery market handled 3.37 billion parcels in 2020 while maintaining annual growth due to the activation of e-commerce. In particular, in the case of the metropolitan area, which accounts for about 70% of the nation's parcel throughput, the increase in parcel delivery volume is directly related to the increase in freight vehicles in central area of Seoul,. And it leads to an increase of unnecessary social and environmental costs such as traffic congestion, road damage, and environmental pollution in the city. Therefore, in this paper we proposed the underground urban logistics system utilizing the existing urban rail infrastructure, and establish a conceptual design by operational scenario. In order to establish conceptual design of underground urban logistics system, we use order picking system process, which is use in warehouse, produce result combined ISO/IEC 26702. The results of this study can be usefully used before the underground urban logistics system is introduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.595-609
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• 2020

In this study, we propose a decentralized mathematical model for predictive control of a system of multi-autonomous unmanned aerial vehicles (UAVs), also known as drones. Being decentralized and autonomous implies that all members make their own decisions and fly depending on the dynamic information received from other unmanned aircraft in the area. We consider a variety of realistic characteristics, including time delay and communication locality. For this flocking flight, we do not possess control for central data processing or control over each UAV, as each UAV runs its collision avoidance algorithm by itself. The main contribution of this work is a mathematical model for stable group flight even in adverse weather conditions (e.g., heavy wind, rain, etc.) by adding Gaussian noise. Two of our proposed variance control algorithms are presented in this work. One is based on a simple biological imitation from statistical physical modeling, which mimics animal group behavior; the other is an algorithm for cooperatively tracking an object, which aligns the velocities of neighboring agents corresponding to each other. We demonstrate the stability of the control algorithm and its applicability in autonomous multi-drone systems using numerical simulations.

• 대한치과교정학회지
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• 제19권2호
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• pp.25-34
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• 1989

This experiment was performed to study the effect of prostaglandin $E_2$ on tooth movement and root resorption in orthodontically treated cats. Twenty five cats were divided into five groups and closed coil springs delivered 80gm were stretched between upper canine and 3rd premolar. $10{\mu}g$ of $PGE_2$ was injected locally in the submucosal area of the upper right canine, while the left side served as a control and was injected saline 0.1ml. The distance between canine tip and central cusp tip of the 3rd premolar was measured. Scanning electron photomicrographs were made of the coronal half of the distal root surface of canines and cemental craterings were observed and quantified using point-counting volumetry. Data were analyzed by 2-way ANOVA and paired t-test. The results were as follows: 1. The rate of tooth movement of the $PGE_2$ side was increased, particularly at 1 day, compared with the control side. 2. The rate of tooth movement was minimum from 7 days to 10 days. 3. The resorption of root surface of the $PGE_2$ side was decreased from 4 days to 10 days, compared with the control side.