치과용 임플란트 적용 비귀금속 코어와 관련된 전조골세포의 변화

박정현,강신영,김종우,김장주,김웅철,김지환,Park, Jung-Hyun,Kang, Seen-Young,Kim, Jong-Woo,Kim, Jang-Ju,Kim, Woong-Chul,Kim, Ji-Hwan 대한치과기공학회 2018 대한치과기공학회지 Vol.40 No.2

Purpose: The purpose of this study is to investigate the non-precious metal core materials used in the dental laboratory to fabricate the implant superstructure by CAD / CAM method. And to observe and compare the morphology and distribution of the osteoblasts in relation to implant osseointegration. Methods: In this study, the mandibular right first molar tooth model was selected as an international standard to produce a single core. Using this model, the impression was made with the silicone rubber, the tooth model was scanned, and a single core was designed and 5-axis milling was performed. The materials used were Cobalt-Chromium and Nickel-Chromium, and the cores for dental implant top structures were fabricated according to the procedures of the dental labs. After the fabrication, the marginal area of the core was separated and cell culture experiment was performed. The osteoblast cells used MC3T3-E1, which is currently widely used. For morphological analysis of osteoblasts, cells were posttreated and observed using CLSM (Confocal Laser Scanning Microscope) and compared. Results: The cell adhesion behavior of the specimen surface measured by CLSM was uniformly distributed in specimen A (Cobalt-Chromium) than in specimen B (Nickel-Chromium). The distribution and changes of the cells were different in the two specimens. Conclusion : It is possible to confirm that specimen A (Cobalt-Chromium) is suitable for the living body through adhesion and proliferation of osteoblasts related to implant osseointegration in the non-precious metal superstructure used after implantation. It is considered that it is preferable to use Co-Cr when fabricating the superstructure.

LNG 연료탱크용 9%Ni강에서 Alloy 625에 의한 Super-TIG 용접 공정 개발

박정현(Jung-Hyun park),홍석한(Suk-Han Hong),홍지웅(Ji-Woong Hong),박철규(Chul-Kyu Park),김민우(Min-Woo Kim),장해주(Hae-joo Jang),이동문(Dong-mun Lee),김광수(Kwang-soo Kim),조상명(Sang-myung Cho) 대한용접·접합학회 2018 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2018 No.4

지능형 감시 시스템 구축을 위한 침입자의 음원 위치 파악 및 추적 시스템

박정현(Jung-Hyun Park),염홍기(Hong-Gi Yeom),정봉규(Bong-Gyu Jung),장인훈(In-Hun Jang),심귀보(Kwee-Bo Sim) 한국지능시스템학회 2007 한국지능시스템학회논문지 Vol.17 No.6

보안이 중요시되는 공간에서 임의의 사람을 추적하고 인식할 수 있는 시스템의 필요성이 점차 중요시되고 있다. 본 논문에서는 wide-area를 감시하기 위해 음원과 Pan-Tilt 카메라를 이용하여 침입자 추적 시스템을 구현하고자 한다. 먼저 음원 추적 센서를 이용하여 음원의 방위를 검출한 후 Pan-Tilt 카메라를 방위 방향으로 이동시키고 이동된 Pan-Tilt 카메라로부터 기준영상을 추출한 후 일정 기준 시간마다 영상을 다시 획득하여 차 영상과 검출결과를 얻어 침입자를 추적하여 감시 시스템을 구현한다. 본 논문에 의해서 구현된 시스템은 홈 네트워크 보안 시스템과 연동을 하여 가정이나 공공시설 보안에 대한 인터페이스 역할을 할 수 있다. In the place that its security is crucial, the necessity of system which can tract and recognize random person is getting more important. In this paper, we'd like to develop the invader tracking system which consists of the sound source tracking-sensor and the pan-tilt camera for wide-area guard. After detecting the direction of any sound with the sound source tracking-sensor at first, our system make move the pan-tilt camera to that direction and extract reference image from that camera. This reference image is compared and updated by the next captured image after some interval time. By keeping on it over again, we can realize the guard system which can tract an invader using the difference image and the result of another image processing. By linking home network security system, the suggested system can provide some interfacing functions for the security service of the public facilities as well as that of home.

삼각형 기법을 활용한 k-means MapReduce 응용

박정현(Jung-Hyun Park),장근석(Kun-Suk Jang),김준수(Jun-Su Kim),강윤희(Yun-Hee Kang),강경우(Kyoung-Woo Kang) 한국정보기술학회 2013 Proceedings of KIIT Conference Vol.2013 No.5

상피성 암세포주에 대한 녹차 Catechin의 효과

박정현(Jeong Hyun Park),김대중(Dae Joong Kim),한장희(Jang Hee Hahn),김홍태(Hong Tae Kim),정용욱(Yong Wook Jung),성훈기(Hoon Ki Sung),김주영(Joo Young Kim),송인환(In Hwan Song),성언기(Eon Gi Sung),이융창(Yung Chang Lee) 대한해부학회 2001 Anatomy & Cell Biology Vol.34 No.5

Catechin은 녹차에서 추출되는 폴리페놀의 주요성분으로 고혈압 및 동맥경화의 예방효과, 당뇨억제효과, 항산화작용, 항암작용 등에 직접 관여하는 물질이다. 본 연구에서는 태평양에서 제공받은 녹차 catechin을 이용하여 상피성 암세포주인 A549 (폐암)와 EATC (복수암)세포에 투여한 후 처리농도와 시간에 따른 변화를 비교, 관찰함으로써 녹차의 효과와 작용기전을 밝혀내는데 목적이 있었다. 본실험은 A549 세포와 EATC 세포를 배양한 후 녹차 catechin을 1, 10, 100, 500 μg/ml의 농도로 48시간 동안 처리하였고, 광학현미경, 공초점현미경, 전자현미경 등을 이용하여 세포의 구조적 변화를 확인하였으며 MTT분석, 전기영동, 유세포분석기 등을 사용하여 세포 손상정도를 파악하였다. A549 세포에서는 catechin 1 μg/ml와 10 μg/ml 농도에서는 대조군에 비하여 큰 변화를 관찰할 수 없었다. 100 μg/ml catechin을 처리하였을 때 세포내의 검은 과립들의 수가 증가하였고 층판소체의 손상이 나타났다. 세포주기의 장애가 나타나 DNA 합성전기에 있는 세포들의 수가 급격히 증가하였다. 500 μg/ml 농도에서는 층판소체와 사립체의 파괴가 심하게 나타났으며 세포생존율이 감소하였고 세포주기의 장애도 관찰되었다. EATC 세포에서는 catechin의 농도가 A549 세포의 경우보다 낮은 농도에서도 세포증식 억제 및 세포손상 효과가 나타났다. 10 μg/ml 농도에서도 세포의 위축과 생존율의 감소가 일어났으며 전기영동상에 괴사되는 세포들이 파악되었다. 100μg/ml catechin을 처리하였을 때 자연사의 형태학적 관찰, 전기영동, 유세포분석 등에서 자연사 과정에 있는 세포들이 많이 나타났다. 결과적으로 녹차 catechin을 배양한 상피성 암세포에 투여함으로서 세포의 생존율과 증식이 억제되었고 그 과정에서 괴사, 자연사, 세포주기의 장애 등이 관여하는 것으로 생각된다. 그러나 일련의 세포손상과정을 유도하는 데 있어 세포의 종류, 처리 시간, 농도에 따라 다소 차이가 있음을 확인하였다. Catechin is main component of polyphenol extracts from green tea, it is associated with prevention of hypertension and atherosclerosis, anti-diabetic effect, antioxidant, antitumor. The purpose of this research is to investigate the effect and its mechanism of green tea catechin on epithelial cancer cell lines in various concentrations and durations. For this study, epithelial cancer cell lines, A549 (lung cancer), EATC (Ehrlich-Lettre ascites tumor cell) were used. Inverted, light, confocal and electron microscopes were applied to find morphological changes. MTT assay, flowcytometric analysis, gel electrophoresis were used to compare severity of cellular damages to control after exposure to 1, 10, 100 and 500 μg/ml catechin for 48 hours. In the A549 cells, after 1 μg/ml and 10 μg/ml catechin treatments, there was no notable changes. However, exposure to 100 μg/ml catechin induced increase of cytoplasmic granules, destruction of lamellar body, inhibition of cell cycle, especially G0/G1. In the early phase of 500 μg/ml catechin administration, decrease of cell population, severe destruction of lamellar bodies and mitochondria, derangement of cell cycle were shown. In the EATC, such as those effects occurred after exposure to lower concentration of catechin than in that of A549 cells. After exposure of 10 μg/ml catechin, rounded-up cells and necrotic cells were found. Whereas, most of cells were under apoptotic changes-cytoplasmic condensation, nuclear fragmentation, cellular shrinkage, ladder pattern in the electrophoresis, when administrated 100 μg/ml catechin. These results suggested that exposure of catechin induced severe cellular damage and growth inhibition in dose- and time-dependent manner. And we confirmed that these effects of catechin were involved with apoptosis, necrosis and cell cycle arrest and were quite different according to cancer type. Therefore, much more research would be demanded before clinical application of catechin to human cancer therapy and this study would be the basic source for further study of green tea.

선박엔진부품 오버레이 용접의 생산성향상을 위한 Super-TIG 용접 공정개발

박정현(Jung-Hyun Park),김영식(Young-Sik Kim),장진호(Jin-Ho Chang),장희철(Hee-Chul Jang),조상명(Sang-Myung Cho) 대한용접·접합학회 2016 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2016 No.4

치위생(학)과 학생들의 현장 실습 후 현장실습 인식도와 진로의사결정과의 관련성

박정현(Jung-Hyun Park),장경애(Kyeung-Ae Jang) 한국구강보건과학회 2018 한국구강보건과학회지 Vol.6 No.2

This study aimed to investigate the association between an awareness of clinical dental field training and career decision making after field training in dental hygiene students. A survey was conducted among students who were enrolled in the department of dental hygiene at universities in the metropolitan cities of Busan and Ulsan and who had had field training experience. Career deci-sion making was positively correlated with the importance of field training (r=0.785, p<0.01) and sat-isfaction with field training (r=0.827, p<0.01). The importance of field training was positively correlated with satisfaction with field training (r=0.817, p<0.01). In the awareness of field training, the significant factors affecting career decision making included the importance of field training (p<0.05) and sat-isfaction with field training (p<0.01). Therefore, education at field training institutions should be system-atically performed through communication and collaboration with the school.

치과위생사의 감염예방 지식수준과 실천도 및 수행도

박정현 ( Jung Hyun Park ),장경애 ( Kyeung Ae Jang ) 한국치위생학회 2012 한국치위생학회지 Vol.12 No.5

Objectives: The purpose of this study is to examine the infection control practice and performance study on knowledge of dental hygienist between their knowledge and general characteristics. Methods: The subjects in this study are 305 dental hygienists who received local in-service education on December 10, 2011 and February 28, 2012. Results: The infection prevention knowledge and performance are higher as work experience is more (p<.05), as the education level is higher and when they have undergone in service education (p<.001). Also these are higher when they are working in the dentist at the present (p<.001). The infection prevention practice are different with respect to ages (p<.01), work experience (p<.001), and the highest level of education (p<.01). There are correlations between the infection control practices and knowledge, performance and knowledge. As the practice level is higher, it is shown that the performance is higher (r=.049, p=.01). Conclusions: It would be necessary to develop the systematic and continuous program in infection control education and to build system which makes in-service training for dental hygienists mandatory. These could improve the level of infection prevention knowledge, practice and performance of dental hygienists to prevent the exposure to infection of the people.

경부고속철도 대전/대구도심 선형개량의 표정속도 향상효과 분석

윤장호(Jang-ho Yun),박정현(Jung-hyun Park),엄기영(Ki-young Eum),류성찬(Seong-chan Ryu),고경남(Kyung-nam koh) 한국철도학회 2012 한국철도학회 학술발표대회논문집 Vol.2012 No.5

고속철도의 속도 특히, 표정속도는 경쟁력의 핵심요소이다. 그럼에도 불구하고 경부고속철도는 최고속도가 300km/h인데 반해, 서울-부산간 표정속도는 약 153km/h로 최고속도 대비 약 51%에 불과하다. 본 연구에서는 현재 진행중인 대전-대구도심 구간 선형개량이 표정속도에 어떠한 영향을 미치는지 TPS(Train Performance Simulation)를 통해 분석하였다. 구체적으로 ①서울-부산 직행, ②대전, 대구 정차, ③6개역 정차 노선을 대상으로, 선형개량 전과 후로 나누어 분석을 실시하였다. 이를 통해 최소 8.5km/h에서 최대 14km/h까지 표정속도가 향상되는 것으로 분석되었으며, 표정속도비로 환산할 경우 최소 2.9%에서 최대 4.6%가량 표정속도가 증가하는 것으로 분석되었다. These days, schedule-speed is one of the most important elements of railway industry competence. From the customers' point of view, high schedule speed means that they can arrive their destinations more rapidly. In Korea, Kyeong-bu HSR's highest speed is 300km/h, yet it's speed schedule is no more than about 153km/h from Seoul to Busan. In this study, we tried to estimate the effects of Daegu and Daejon track alignment improvement to Seoul-Busan speed schedule using Train Performance Simulation. We found that the two cities' track improvements can raise the speed schedule from 3% to 5% depending on the number of stop stations.

경부고속철도의 표정속도 향상 가능성에 대한 고찰

윤장호(Jang-ho Yun),엄기영(Ki-young Eum),박정현(Jung-hyun Park),류성찬(Seong-chan Ryu) 한국철도학회 2011 한국철도학회 학술발표대회논문집 Vol.2011 No.10

The domestic railway has high speed trains as good as those of countries outside Korea but the schedule speed in the domestic railway which is calculated by dividing distance to destination by time is lower than that of overseas trains. The object of this study is the necessity for the improvement of schedule speed in the Kyeongbu High speed railway. This study was conducted with analyzing foreign cases related to the improvement of schedule speed in order to satisfy the increasing traffic demand. The schedule speed against the high speed of railway advanced countries is over 65% while it is about 50% in the domestic railway. In conclusion This study confirmed that there are possibilities and plans about the improvement of schedule speed for using TPS analysis in the Kyeongbu High speed railway.