지혈제가 상아질과 레진 결합력에 미치는 영향

조정현,이은정,소경모,김원,오남식,한상현,송경화,Cho, Jeong-Hyun,Lee, Eun-Jeong,So, Kyung-Mo,Kim, Won,Oh, Nam-Sik,Han, Sang-Hyun,Song, Kyung-Hwa 대한치과보철학회 2008 대한치과보철학회지 Vol.46 No.4

목적: 산부식제 적용후 치은 자극으로 인하여 지혈제를 사용할 때 다양한 pH를 가진 지혈제를 적용후 pH에 따른 레진 결합력 차이와 산부식제 재적용 여부에 따른 결합력 회복 정도를 비교하는 것이다. 재료 및 방법: 본 실험에서 사용된 지혈제 중 보스민, 아스트리제덴트, 헤모덴트로 대부분의 지혈제는 산도가 낮다. 또한 바이진은 눈의 충혈제거제로써 성분은 중성이다. 실험방법은 먼저 치관이 건전한 90개의 대구치 10개씩 9그룹으로 나눠 교정용 레진에 식립 한 후 치축과 수직으로 섹션 후 연마한 뒤 대조군은 통상적인 방법으로 산부식과 접착제를 도포 하고, 실험군은 산부식한 뒤 각각의 지혈제를 30초간 오염시킨다. 그 뒤 린스만 한 N 그룹과, 린스 후 산부식제 재적용한 R 그룹으로 나누어서 처치하고 처치한 상아질에 셀룰로이드 캡슐을 이용해 레진 접착을 시행한다. 그리고 인스트론을 이용해 전단력을 측정한다. 통계 분석은 유의수준 0.05 이하로 비교했다. 결과: 대조군과 비교하였을 때, Visine을 제외한 모든 지혈제에서 평균 결합력이 낮아짐을 볼 수 있었으나 통계적으로는 유의할만한 차이는 없었다. 또한 린스만 한 N군과 산부식제 재적용한 R군을 비교했을 때 모든 군에서 결합력 증가가 있었으나 통계적으로는 유의할만한 차이는 없었다. 결론: 임상에서 적용하는 30초의 짧은 적용 시간에는 pH에 따른 지혈제의 영향은 결합력에 영향을 줄 만큼 크지 않고 산부식제 재적용 등 다른 처치를 하지 않아도 린스를 하는 것만으로도 충분히 결합력 회복이 가능하다는 결론을 도출하게 되어 임상과정을 간단하게 하는데 도움이 될 것으로 생각된다. Purpose: This study examined the recovery of the dentin-resin bonding strength, and the difference in the bonding strength after applying pH hemostatic agents at various pH. Materials and methods: Bosmin, Hemodent, Astregedent, and Visine were used as the hemostatic agents in this study. The Bosmin, Hemodent, and Astrigedent hemostatic agents are acidic, and the Visine hemostatic agent is neutral and is used as a decongestant. Ninety human molar teeth were used as the specimen. The teeth were sectioned using a diamond wheel until the dentin was exposed and wet ground by silica paper. The specimens were divided into two groups according to the hemostatic agent used. The specimens were then subdivided into 9 groups according to the application of re etching (R group) or rinsing only (N group). A commonly used resin bonding procedure was used in the control group. The resin bonding procedure was managed dentin using celluloid capsule. In addition, the shear bond strength was measured using an Instron. Results: In general, samples with the applied hemostatic agent, with the exception of Visine, had a slightly weak bond that was similar to the control group. In addition, the rinsing only (N) group had slightly weak bond that was similar to the re etching (R) group. Conclusion: The application of a hemostatic agent on the dentin surface does not affect the shear bond strength after application for a short time. In addition, rinsing only can recover the shear bond strength making other management procedures redundant, particularly re etching.

Evaluation of Performance for Shape Extraction using Modified Chain Code and Color Information with Spatial Relationship

조정현,Cho, Jeong-Hyun 한국정보과학회 2004 정보과학회논문지 : 기술교육 Vol.1 No.1

본 논문은 클립아트 이미지로부터 색상정보와 모양정보를 추출한 후에 다른 클립아트 이미지로부터 추출된 색상정보와 모양정렬 사이의 유사성을 측정하는 방법에 대해 제안한다. 클립아트 이미지의 모양정보를 표현하기 위해서, 제안된 방법은 사각형의 비율을 이용해서 외각선을 오목면과 볼록면의 비율로 표현한다. 모양의 외각선은 사각형으로 표현되고 체인 코드로 변환한다. 반면에, 색상은 HSV 색상 좌표계로 양자화된 간 색상 영역사이의 위치 정보 그리고 색상 영역사이의 크기로 표현된다. 이 색상정보는 자연 이미지보다 적은 칼라수를 가지는 클림아트를 표현하는 데 있어 보다 나은 정확성을 갖는다. 실험 결과는 모양과 색상을 표현하는 데 있어 이전에 연구되었던 방법보다 제안된 방법이 우위에 있음을 보여준다. This paper presents a method of extracting shape and color information from clipart images, then measuring the similarity between different clipart images using the extracted shape and color information. To represent the shape of clipart images, the proposed method expresses the convex and concave aspects of an outline using the ratio of a rectangle. The shape outline is then expressed using a rectangle representation and converted into a chain code. Meanwhile, the color is represented by color values quantized into HSV color coordinate, the location information between the color regions and the size of the color regions. These color information can more appropriate for representing clipart images, which have a smaller number of colors than nature images. Experimental results demonstrated that the proposed method is superior in expressing shape and color information than previous methods.

미국 코하우징의 특성 및 주민참여 현황

조정현,최정신,Cho, Jeong-Hyun,Choi, Jung-Shin 한국주거학회 2011 한국주거학회 논문집 Vol.22 No.2

Since the cohousing idea, originated in Northern Europe, was introduced in the U.S. by architects Kathryn McCamant and Charles Durrett in the early 1980s, there are recently the largest number of cohousing communities and rapidly expanded in the U.S. So, it is necessary to appreciate the cohousing communities developed in U.S. In this study, we investigated the physical characteristics of cohousing and the methods of its residents' participation by means of a case study on cohousing communities in U.S. and suggested the future direction of the cohousing community. Also, this work could be exploited when the cohousing is introduced to Korea. At first, the general status and characteristics of U.S cohousing was explored using diverse sources such as literature, paper and Web site. And then, the direct visit survey was used to obtain the more exact and specific data about physical aspects and residents' participation in each community. We found that cohousing communities were mostly located in the urban and Rural area, which was founded in the 1990s, and new communities continue to be created in the U.S. Typically, the number of households is from 20 to 30 in one community. The land is generally owned by the community itself and its size is within 10 acres. Communities usually serve optional group meals in the common house at least two or five times a week. Each member's income is separated and the community members should take care of their common properties. The leader of community does not exist and most communities don't have the organization of community members. All cohousing communities use consensus as the basis for group decision-making.

주거가치에 따른 코하우징 거주의사에 관한 연구

조정현,홍서정,곽유미,곽인숙,최정신,Cho, Jeong-Hyun,Hong, Seo-Jung,Kwak, Yu-Mi,Kwak, In-Sook,Choi, Jung-Shin 한국주거학회 2007 한국주거학회 논문집 Vol.18 No.5

This is a basic study to investigate possibility to application of cohousing model into Korea. Purpose of this study is to grasp respondents' housing value, and its influence on intention to live in cohousing. Research method used for this study was a social survey. Respondents were 214 married people residing in Seoul and its outskirts by accidential sampling. The collected data were analyzed by SPSS 12.0 program using frequency, mean, average, factor analysis, t-test, one-way ANOVA, Duncan's multiple range test, multiple regression and legit analysis. Result of this study was as follows. Housing values were classified into three categories named as individualism oriented housing value, tradition oriented housing value, and economy oriented housing value. Housing values were different by respondents groups. For example, individualism oriented housing value showed difference according to age and housing area. Tradition oriented housing value showed difference according to sex, occupation, and period of residence, while economy oriented housing value showed difference according to housing type, and home ownership. In detail, men than women, single-income family than double-income family, and detached house resident than flat resident had higher tradition oriented housing value. The younger than the elder, and Seoul resident than outskirts resident had higher economy oriented housing value. Also home owner than tenant, and the higher tradition oriented group had stronger intention to live in cohousing than others.

코하우징 계획을 위한 주민참여 워크숍 사례 - 30~40대 주부를 대상으로 -

조정현,최정신,Cho, Jeong-Hyun,Choi, Jung-Shin 한국가정관리학회 2009 가정과삶의질연구 Vol.27 No.6

Resident participation plays much of a rule to the cohousing, which is organized independently and has the characteristics of community life, especially in the initial state of cohousing process. However, it is hard to realize the resident participation in proper order due to lack of a personal time, individual effort and an insufficient knowledge related with cohousing. So, it is thought that the guidance of cohousing expert and coordinator is needed to enable the residents to perform in an active attitude. The development of educational program and workshop connected with resident participation is also accompanied. In this study, to make the positive and systematic participation of cohousing residents, we established the workshop program and performed workshop with our developed program, based on preceding researches and examples. We selected the object of workshop as five housewives in thirties and forties. Workshop was consisted of six process steps. (1) Introduction and question of workshop and cohousing (2) examining and arranging the opinion (3) Master plan of cohousing village (4) Planning of common living space (5) Planning of individual living space (6) Analysis of final results and evaluation of workshop. The workshop held six times and it took about five~six hours per each meeting. Workshop participants expressed their opinion actively and attended in a positive manner in order to the design of their desired village and cohousing. During workshop process, the players established the common target of their village by means of life card, target card game. Also, based on the common target, the layout of village was planned using a collage game and card arrangement game. By workshop activity, the members started to recognize the significance of participation on the drawing board and improve their technique of communication and decision-making. Furthermore, workshop process made it possible to approach the concrete forms of their cohousing village. Especially, in the closing phase, the participant satisfaction about workshop and cohousing is increased suddenly and expressed their intention to join the real workshop related with cohousing.

임베디드시스템 환경에서 하드웨어 기반 H.264 Encoder 최적화

조정현(Cho, Jung-Hyun),이명수(Lee, Myung-Soo),정한수(Jeong, Han-Soo),김창석(Kim, Chang-Suk),조대제(Cho, Dae-Jea) 한국산학기술학회 2010 한국산학기술학회논문지 Vol.11 No.8

영상 압축 코덱(Codec)을 활용하여 군 혹은 민간 분야에서 다양한 기술과 제품들이 출시되고 있다. 기존 고 성능 PC환경 하에서 영상 압축 코덱의 프로세스는 큰 문제가 되지 않았지만, 제한적인 시스템 자원을 가지는 임베 디드 시스템 환경에서는 고해상도의 영상을 고밀도 압축하면서 발생하는 시스템 부하로 인하여 성능 및 활용도가 제 한되는 문제가 부각되고 있는 상황이다. 본 논문에서는 임베디드 시스템 환경 상 기존 소프트웨어 알고리즘 형태의 영상 압축 방식에 대한 성능 및 주변 장치 연동 인터페이스 제약에 대한 해결책으로서 하드웨어 방식의 영상 압축 코덱성능 최적화, 외부 장치 연동의 편의성 및 확장성을 부각하기 위한 DirectShow 필터 인터페이스화를 제안하였고 검증을 위해 임베디드 시스템을 구현해서 시뮬레이션 하였다. The techniques and the products which use various video compression codec are come out from army or civil field. In existing high-end PC environment, process of the video compression codec does not become a problem, but in embedded system environments which limited system resources, because the system load due to the high-resolution images compressed by high-density, issues of performance and utilization are highlighted. This paper proposes the DirectShow Filter interfaces which are a hardware method in order to solve the problem existing software algorithms for image compression performance and peripheral interfaces.

방범 관제를 위한 실시간 원격 모니터링 엠비언트 시스템 개발

조정현(Cho, Jeong Hyun),권용진(Kwon, YongJin) 한국통신학회 2010 한국통신학회 학술대회논문집 Vol.2010 No.6

The approach for supporting synchronous Ethernet in 10G EPON

Jeong-hyun Cho(조정현),Cheol-woong Ahn(안철웅),Yong-suk Chang(장용석) 한국산업정보학회 2013 한국산업정보학회논문지 Vol.18 No.6

In recent, many countries and research institutes have been studying how to construct the high-speed subscriber access network. Task Force team of IEEE 802.3ah has accomplished the standardization of EPON which is the next generation subscriber access network. EPON doesn’t still have the bandwidth enough to support the new service(e.g various multimedia service) which demands the high bandwidth. For these new multimedia services,10G EPON is the next generation subscriber access network which expanded the up-down bandwidth range of 1G EPON 10 times in order to support demanding high bandwidth. We have proposed the model which can accommodate IEEE 802.1 AVB traffics smoothly in 10G EPON and suggesting the Intra-ONU scheduling model which makes this model operate effectively.

투명한 사출성형품에서 어닐링 조건에 따른 잔류응력 이완에 관한 연구

조정현(Jeong Hyun Cho),박서리(Seo Ri Park),김혁(Hyeok Kim),류민영(Min Young Lyu) 한국고분자학회 2012 폴리머 Vol.36 No.2

사출성형품은 성형 중 온도변화와 전단응력에 의해 잔류응력이 형성된다. 이 잔류응력으로 인해 짧게는 하루 이내에 길게는 수 년 이상 시간이 흐른 뒤 변형과 뒤틀림 등이 발생될 수 있다. 따라서 잔류응력 최소화를 위 한 사출성형조건 및 사출성형품의 열처리가 요구된다. 본 논문에서는 투명한 사출성형품을 어닐링 조건 즉, 상대 습도와 온도, 그리고 어닐링 시간을 변화시켜가며 각 어닐링 조건이 잔류응력 해소에 미치는 영향을 조사하였다. 상대습도가 작을 경우 잔류응력의 해소가 매우 적었으나 상대습도 50% 이상에서는 그 영향이 크게 작용하였다. 또한 유리전이온도 부근에서 어닐링 시 매우 빠른 잔류응력 해소를 보였으며 이는 광탄성 장치를 통하여 관찰할 수 있었다. 상대 습도보다는 어닐링 온도가 잔류응력 해소에 더 큰 영향을 미치고 있음을 확인할 수 있다. 시편에 서 잔류응력이 해소되면서 시편에서 수지의 흐름방향으로는 수축이, 흐름의 직각방향으로는 팽창이 발생하여 변형이 일어나는 것이 관찰되었다. 어닐링 시 제품의 변형을 최소화 하기 위해서는 지그나 고정구로 시편을 구속 한 환경에서 어닐링이 필요할 것으로 판단되었다. Residual stress is developed in the injection molded articles during the molding process due to temperature variation and shear stress. The residual stress causes the deformation and warpage in the injection molded parts shortly within several days or after several years. Therefore, the injection molding conditions should be optimized to reduce the residual stress. And residual stress in the part should be also relaxed after molding process to maintain its shape. According to the annealing conditions, such as relative humidity, temperature and time, this study investigates the relaxation of residual stress generated in the transparent injection molded specimens. Through the experimental results, it was realized that the residual stress was relaxed at a relative humidity higher than 50%. Utilizing photoelasticity equipment, it was found that the residual stress was rapidly relaxed near glass transition temperature. Additionally, we recognized that the specimen shrunk along the flow direction but expanded to the perpendicular direction of the flow during the annealing processes, which resulted in the warpage of the specimen.

반복적 캠버변형 기법을 이용한 조종면이 있는 날개의 비선형 공력특성 해석

조정현(Jeong-hyun Cho),정용인(Yong-in Joung),조진수(Jin-soo Cho) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.5

본 연구에서는 주파수 영역 패널법을 이용하여 조종면이 있는 날개의 비선형 공력특성을 해석하였다. 날개의 비선형 공력특성을 해석하기 위해 반복적 캠버변형 기법을 도입하였다. 캠버변형 기법은 기지의 에어포일 공력특성을 이용하여 날개의 비선형 공력특성을 해석한다. 날개의 한 단면에서의 에어포일 캠버변형이 날개의 다른 단면에 미치는 영향은 다차원 뉴턴 반복법을 사용하여 고려하였다. 해석결과를 실험값과 비교하여 본 방법의 유효함을 보였다. 본 방법은 많은 계산 자원을 요하지 않으면서 신속하게 날개의 비선형 공력특성을 예측할 수 있어 항공기 설계 초기 단계에서 유용할 것으로 생각된다. The nonlinear aerodynamic analysis of wing with control surface is performed using the frequency-domain panel method. To take into consideration the nonlinear aerodynamic characteristics of wing an iterative decambering approach is introduced. The iterative decambering approach uses the known aerodynamic characteristics of airfoil to calculate the aerodynamic characteristics of wing. The multi-dimensional Newton iteration is used to account for the coupling between the different sections of wing. The present method is verified by showing that it produces results that are in good agreement with experiments. The present method will be useful for the analysis of aircraft in the conceptual design because the present method can calculate promptly the nonlinear aerodynamic characteristics of wing with a few computing resources.