• Restorative Dentistry and Endodontics
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• v.41 no.1
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• pp.1-5
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• 2016

Objectives: The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison. Materials and Methods: Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at ${\alpha}=5%$. Results: Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001). Conclusions: PTG system produced overall less canal transportation in the curved portion when compared to PTU system.

• Journal of Korean Home Economics Education Association
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• v.12 no.3
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• pp.1-17
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• 2000

The purpose of this research was to apply and conduct a class with Gordon’s Creative Problem Solving Method(Synectics) to the area of ’human development and family relations’among male students in a jr. high school. Subject matters which were appropriate for applying Gordon’s Creative Problem Solving method were selected from ’human development and family relations’area, with problem circumstances set to reflect to the highest degree the interests of individuals and families. An 8 hour teaching instructional guide was constructed with $\boxdr$strategy 1$\boxul$of Gordon’s Creative Problem Solving method in order to solve creatively the established problem. This was practically implied to 70 students(each class had 34 and 36 students respectively) in K middle school located in Seoul. The period of this application was for 3 months during March through May of 1999. The perception of this method was examined by the teachers and students through open-ended questions. The record of perception showed that 56 students out of 70(with no response from 5 students) through that the class done by the creativity problem solving method was good. The majority of reasons mentioned for the positive answers were ’being able to receive different thoughts which were unusual of daily life’. In addition the students who participated in the class were able to foster a joint experience which improved their understanding of relationships and sens of community. moreover students who did not do well n the class or were diffident were encouraged to participate which in result showed that there was even an internal effect.

• Journal of Biosystems Engineering
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• v.19 no.2
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• pp.124-137
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• 1994

Visual features of a mushroom(Lentinus Edodes, L.) are critical in grading and sorting as most agricultural products are. Because of its complex and various visual features, grading and sorting of mushrooms have been done manually by the human expert. To realize the automatic handling and grading of mushrooms in real time, the computer vision system should be utilized and the efficient and robust processing of the camera captured visual information be provided. Since visual features of a mushroom are distributed over the front and back sides, recognizing sides and states of the stalk including the stalk orientation from the captured image is a prime process in the automatic task processing. In this paper, the efficient and robust recognition process identifying the front and back side and the state of the stalk was developed and its performance was compared with other recognition trials. First, recognition was tried based on the rule set up with some experimental heuristics using the quantitative features such as geometry and texture extracted from the segmented mushroom image. And the neural net based learning recognition was done without extracting quantitative features. For network inputs the segmented binary image obtained from the combined type automatic thresholding was tested first. And then the gray valued raw camera image was directly utilized. The state of the stalk seriously affects the measured size of the mushroom cap. When its effect is serious, the stalk should be excluded in mushroom cap sizing. In this paper, the stalk removal process followed by the boundary regeneration of the cap image was also presented. The neural net based gray valued raw image processing showed the successful results for our recognition task. The developed technology through this research may open the new way of the quality inspection and sorting especially for the agricultural products whose visual features are fuzzy and not uniquely defined.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.239-244
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• 2006

최근 인터넷에서 많은 관심을 보이고 있는 개인 미디어(UCC;User Created, Contents, VC2;Viewer Created Contents, 이하 UCC-사용자가 직접 제작한 미디어 콘텐츠를 불특정 다수에게 제공하는 서비스) 중에 비디오/오디오 콘텐츠를 영상 콘텐츠의 기본적인 매체라 할 수 있는 TV상에서 직접 즐길 수 있다면 미디어의 대상과 그 미디어의 Entertainment적인 효과는 배가될 것이다. 디지털 케이블 방송에서 UCC와 같은 다양하고 많은 미디어 콘텐츠를 디지털 TV상에서 서비스를 하고자 한다면 현재의 OCAP(OpenCable Application Plat form)기반에서는 RVOD(Real Video on Demand)와 동일한 서비스 모델을 가져야 하는 부담과 UCC 제공을 위한 방송 플랫폼별 인터페이스가 필요할 것이다. 이러한 문제점을 Return Path를 통한 RTP(Real-time Transport Protocol;RFC1889)을 이용해서 기존의 VoD(Video on Demand)스트림의 대역에서 분리하고 별도의 VOD프로토콜을 구현함으로써 라이브 방송환경과 동일한 인프라의 지속적인 확장보다는 일반적인 네트워크 프로토콜을 이용하여 VoD서비스를 위한 인프라에 많은 영향을 받지 않는 서비스가 가능할 수 있을 것이다. 따라서 본 논문에서는 RTP를 위한 Set-Top-Box상의 다운로드 가능한 구조의 클래스 분석과 클라이언트 대응의 UCC Transcoding 및 전송을 위한 스트리밍 서버의 설계에 중점을 두고 경량화 된 VOD서비스 및 시스템을 설계함으로써 방송환경 하에 On-Demand서비스의 효율적인 확장성과 보다 많은 콘텐츠 등록 및 활용의 기회를 가져올 수 있을 것으로 기대한다.

• School Mathematics
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• v.7 no.4
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• pp.445-467
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• 2005

The purpose of this study was to investigate mathematics teaching of an elementary school teacher and to understand the meaning of it. This study was a qualitative case study using by analyzing metaphors. The notion of metaphors was newly set up. Traditionally, it had been regarded as a mere tool for better understanding, but it was recognized as the primary source of all of our concept(Sfard, 1998). The subject of this case study was a researcher 'I' and also an elementary school teacher. The three selves named Mee1, Mee2, Mee3, respectively. Mee1 was the 'I' who developed the 4th graders' activities on mathematical patterns in 1996 and wrote mathematics textbook for the 4th graders in 1998-1999. Mee2 was the 'I' who taught mathematical patterns to her students in 2002. Mee3 was the 'I' who criticized the teaching of Mee2 in 2005. [ADVENTURE], [HIDE-AND-SEEK], and [FIREWORKS DISPLAY] were deter-mined to be key metaphors of mathematics teaching. [ADVENTURE] of Mee] was focused on profound understanding of mathematics, [HIDE-AND-SEEK] of Mee2 on construction of mathematics, and [FIRE-WORKS DISPLAY] of Mee3 on making meaning and participating in communities. Studies of metaphors give us the power of understanding mathematics teaching and also generate it. And viewing mathematics teaching via metaphors makes teaching studies open to new ways.

• Lingua Humanitatis
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• v.5
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• pp.55-74
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• 2003

The issues concerning the nature of the attitude toward the study of national language may vary from country to country, depending on the national or racial characteristics. The problem domains and the methodologies dealing with them may vary accordingly. Ever since the Korean language was equipped with a writing system in the year of 1443 through King Sejong's long-cherished desire, investigations have been constantly made into the real nature of the language itself in pursuit of a better method for representing the spoken language in written form. This is how the study of the Korean language began to take shape. Among such investigations are Hunmin-jeong-eum(the Korean script: 1446) compiled by Jiphyon-jon, the royal office of schloarly researches, Doongguk-jeonghun-yokhun (the orthodox script of Korean: 1448), Hongmu-jeonghun-yeokhun(interlinear gloss for the Chinese script of the Ming Dynasty: 1455), An Orthodox Approach to Written Korean (1909) by the institute of the National Script, Re Standardized Spelling System (1933) by Chosun Language Society, An Authorized Dictionary of Standard Korean (1936), How to Write Borrowed Words(1940), and A Grand dictionary of Korea (1947-57). Chu Shi-Gyung's Phonetics of the Korean Script(1908), Korean Grammar(1910), and Sound Patterns of Korean(1914) were all written in this vein; so was Choi Hyun-Bae's Uri-mal-bon (the rudiments of Korean Grammar: 1929/1937). All these achievements in the study of the Korean language are the end-products of the constant endeavor to solve the issues related to the spoken and written farms of the Korean language. And this is how the uniqueness and autonomy of the language study in korea have been established. It should be borne in mind, however, that, in seeking solutions to the problems inherent in the Korean linguistic studies of foreign countries. On the contrary, they have been very active in accommodating such results. While they have set up their problem domains on the basis of the korean language, they been progressively open-minded in looking for the solutions to the problems at hand.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.91-99
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• 1999

Vapor-liquid equilibrium apparatus is designed and set up. The equilibrium data of two binary systems, HFC-32/143a and HFC-143a/134a, are measured. Fifteen equilibrium data for HFC-32/143a and HFC-143a/134a systems are measured over the temperature range 263.15~283.15K at 10K interval and the composition range 0.10~0.80, respectively. And vapor-liquid equilibrium data are calculated using equation of state and correlation of activity coefficient and compared with the present data. Equation of state is used CSD and RKS equations and correlation of activity coefficient is used Margules' and Van Ness and Abbott's correlations. Real behavior of HFC-32/143a system has very large deviation with Raoult's rule which is ideal behavior. But real behavior of HFC-143a/134a system is similar to ideal behavior. The calculated data from CSD equation are compared with the data in the open literatures and the calculated data from REFPROP. In the results for REFPROP, the relative deviations of bubble point pressure for HFC-32/143a system are within -2.16~0.84% for CSD equation and within -0.20~1.10% for RKS equation. And the relative deviations of bubble point pressure for HFC-143a/134a system are within -0.45~0.12% and -0.20~2.8% for CSD and RKS equations, respectively.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.5
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• pp.282-290
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• 2013

The effects of the combination of blade number for forward and after propeller on the propeller shaft forces of a contra-rotating propeller (CRP) system are presented in the paper. The research is performed through the numerical simulations based on the Reynolds-Averaged Navier-Stokes equations (RANS). The simulation results of the present method in open water condition are validated comparing with the experimental data as well as the other numerical simulation results based on the potential method for 4-0-4 CRP (3686+3687A) and 4-0-5 CRP (3686+3849) of DTNSRDC. Two sets of CRP are designed and simulated to study the effect of the combination of blade number in behind-hull condition. One set consists of 3-blade and 4-blade, while the other is 4-blade and 4-blade. A full hull body submerged under the free surface is modeled in the computational domain to simulate directly the wake field of the ship at the propeller plane. From the simulation results, the fluctuations of axial force and moment are dominant in the case of same blade numbers for forward and after propellers, whereas the fluctuations of horizontal and vertical forces and moments are very large in the case of different blade numbers.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.115-123
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• 2008

The purpose of this research is how to build the film industry cluster compare with the policies of metropolitan areas and local film industry. This research select four areas including Seoul and Kyunggi areas and Busan, Jeonju. And through the compare with the film industry infra & policies which results in as follows. This research suggest that film industry cluster devided into the two types. The one is the Film Industry Cluster Type and the other is Film Connected Tourism Business Cluster Type. Film Industry Cluster Type is devided into international competitive cities and domestic film industry cities. We suggest that Seoul, Kyunggi and Busan areas are designated to international competitive cities and Jeonju and Daejeon areas are designated to domestical cities. And the kwangwon, Chungcheng, Cheju Areas designated to Film Connected Tourism Business Cluster for location and open set business to improve the local development.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.4
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• pp.83-105
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• 2015

Taxi, one of the passenger services, is an essential transportation system in our society. In spite of the importance of taxi service, deterioration of the service quality is continuously reported. In particular, taxi service failures due to traffic accidents have emerged as the most serious social problem which may incur a considerable amount of social costs. In this study, we focus on analyzing the causes of service quality deterioration-traffic accidents of both corporately owned and privately owned taxies in Seoul. The research objective is to find out the determinants of service quality deterioration of Taxi industry and to suggest policies for improving the taxi service in Seoul. We collected the archival data from KTSA (Korea Transportation Safety Authority) and ODP (Open Data Portal), which span from 2005 to 2014. Hierarchical regression analyses and a set of mediation tests are conducted. The root factors inducing traffic accidents of taxies are divided into competitive, and profitability factors. The statistical results indicate that the accident ratio per taxi is not only affected by competitive/profitability factors such as number of active taxi drivers, number of bus passengers, and taxi fare, but also mediated by the traffic violation ratio. To alleviate the current problems with taxi service in Seoul, we conclude that the number of taxies be reduced and the taxi fare be increased. Finally, we suggest several policies to improve the endemic taxi industry problems, over-supply and the low profitability by enhancing the linkage between service quality and profitability.