성견에서 Titanium Plasma Sprayed IMZ 임플란트에 가해진 조기 기능하중의 골유착 및 골형성에 미치는 영향

전영식,한동후,Jeon, Young-Sik,Han, Dong-Hoo 대한치과보철학회 1995 대한치과보철학회지 Vol.33 No.3

The purpose of this study was to observe the effects of early functional on bone formation around titanium plsama sprayed IMZ implants. 15 IMZ implants were inserted on the mandibular premolar areaa in 5 mondgrel dogs. The inplants were divided into 4 groups according to it’s loading schedule : Temporary abutments were connected for functional loading 6weeks, 9weeks, and 12weeks after implants installation in group I, II, and III, respectively. Abutments were not connected in the control group. After polyfluorochrome sequential labeling, all animals were sacrificed and bone sections includig implants and the 1st. molar were removed and processed for histologic evaluation. From light and fluorescence microscopic evaluation as well as histomorphometric and EPMA analysis, following results were obtained : 1. Light microscopically, the osteoid tissues were observed much in the compact bone of unloaded group, and cancellous bone formation observed more in early loaded group. 2. Calcification and remodeling of bone took place faster in loaded group, especially in 6 weeks group. 3. Moderate to severe marginal bone resorption was observed in 6 weeks group, mainly on buccal crest. 4. There was no difference in the percentages of bone-to-metal contact among the experimental groups. 5. In quantitative analysis using EPMA, there was no difference in the content of calcium and phosphorus among the experimental groups, regardless of distance.

MicroC/OS-2 실시간 운영체제에서의 우선순위 역전현상 해결을 위한 일시적 우선순위 교환 프로토콜 설계 및 구현

전영식 ( Young Sik Jeon ),김병곤 ( Byung Kon Kim ),허신 ( Heu Shin ) 한국정보처리학회 2009 정보처리학회논문지 A Vol.16 No.6

실시간 운영체제는 효율적인 스케줄링, 최소화된 인터럽트 지연, 우선순위 역전현상 해결 등의 다양한 조건을 만족시킴과 동시에, 응용프로그램이 정해진 기한 내에 수행되는 것을 보장하여야 한다. 따라서 실시간 운영체제는 상기 조건을 만족시킬 수 있도록 설계/개발되어야 한다. 대중적인 실시간 커널의 한 종류인 MicroC/OS-II에서는 우선순위 역전 현상에 대한 해결 기법으로 뮤텍스(Mutex)를 사용한 기본적인 우선순위 상속(Basic Priority Inheritance) 프로토콜을 사용한다. 뮤텍스를 구현하려면 우선순위가 같은 여러 태스크를 사용할 수 있도록 커널이 지원해야 하나 MicroC/OS-II 운영체제는 우선순위가 같은 여러 태스크의 동시 사용을 지원하지 않는다. 이를 해결하기 위해 추가적인 우선순위 예약을 사용할 수밖에 없게 되고, 결과적으로 제한된 우선순위 자원을 낭비하게 된다. 본 논문에서는 MicroC/OS-II의 불필요한 우선순위 자원을 낭비하는 문제점을 해결할 수 있는 일시적 우선순위 교환 프로토콜(Temporary Priority Swapping Protocol; TPSP)을 설계 및 구현하여, 한정된 자원 환경을 가진 임베디드 장비에 효율적으로 운용되도록 하는데 목적을 둔다. Real-time operating systems must have satisfying various conditions such as effective scheduling policies, minimized interrupt delay, resolved priority inversion problems, and its applications to be completed within desired deadline. The real-time operating systems, therefore, should be designed and developed to be optimal for these requirements. MicroC/OS-II, a kind of Real-time operating systems, uses the basic priority inheritance with a mutex to solve priority inversion problems. For the implementation of mutex, the kernel in an operating system should provide supports for numerous tasks with same priority. However, MicroC/OS-II does not provide this support for the numerous tasks of same priority. To solve this problem, MicroC/OS-II cannot but using priority reservation, which leads to the waste of unnecessary resources. In this study, we have dealt with new design a protocol, so called TPSP(Temporary Priority Swap Protocol), by an effective solution for above-mentioned problem, eventually enabling embedded systems with constrained resources environments to run applications.

유지부의 수직거리가 Clasp의 유지력에 미치는 영향에 관한 실험적 연구

전영식(Young Sik Jeon),이호용(Ho Yong Lee) 대한치과의사협회 1986 대한치과의사협회지 Vol.24 No.12

MicroC/OS-II에서의 효율적인 메모리 관리에 관한 연구

전영식 ( Young-sik Jeon ),허신 ( Shin Heu ) 한국정보처리학회 2008 한국정보처리학회 학술대회논문집 Vol.15 No.2

MicroC/OS-II에서는 연속된 메모리 공간으로 구성된 파티션에서 고정 크기의 메모리 블록을 할당할 수 있는 방법을 제공하며, 이 파티션은 사용 가능한 메모리 블록의 개수를 유지하고, 모두 같은 크기를 갖는 메모리 블록을 단일 연결 리스트의 형태로 관리 한다. 이런 형태의 메모리 관리 시스템은 메모리 단편화 현상이 잘 일어나지 않지만 이런 단순한 구조로 메모리 공간을 통합 관리, 블록을 할당하고 반환하는데 필요한 검사등을 효율적으로 수행할 수 없다. 본 논문에서는 MicroC/OS-II에서의 단편화문제를 해결하는 방법에 더 나아가 효율적으로 메모리를 통합하고 관리하는 방법에 대해 제안하고자 한다.

MicroC/OS-II 실시간 운영체제에서의 우선순위 역전현상 해결 방법에 관한 효율적인 연구

전영식 ( Young-sik Jeon ),허신 ( Shin Heu ) 한국정보처리학회 2009 한국정보처리학회 학술대회논문집 Vol.16 No.1

MicroC/OS-II에서는 우선순위 역전 현상에 대한 해결 기법으로 뮤텍스를 사용한 기본적인 우선순위 상속(Basic Priority Inheritance)을 사용한다. 뮤텍스를 구현하려면 리얼타임 커널이 우선순위가 같은 여러 태스크를 지원해야 한다. 하지만 MicroC/OS-II는 우선순위가 같은 여러 태스크를 지원하지 않는다. 이를 해결하기 위해 MicroC/OS-II는 우선순위 예약을 사용할 수밖에 없었으며 이로 인해 불필요한 메모리공간 및 우선순위 자원을 낭비하게 된다. 본 논문에서는 MicroC/OS-II에서의 불필요한 메모리 낭비와 우선순위 낭비를 줄여, 적은 용량의 메모리를 가지는 임베디드 장비에 효율적으로 운영되도록 제안 하고자 한다.

전극길이 변화에 따른 실린더 형태 ER밸브의 성능고찰

전영식(Young-Sik Jeon) 한국공작기계학회 1998 한국공작기계학회지 Vol.7 No.6

지상파방송과 종합편성채널 보도교양프로그램의 심의 사례 분석-4기 방송통신심의위원회의 심의내용을 중심으로

전영식(Young Sik, Jeon) 동국대학교 영상문화콘텐츠연구원 2019 영상문화콘텐츠연구 Vol.17 No.-

본 연구는 제4기 방송통신심의위원회가 출범한지 1년이 지난 현재, 지상파와 종합편성채널의 보도교양부문의 심의결과를 분석하여 심의 경향과 특징에 대하여 알아보고자하였다. 분석결과, 벌점이 없는 행정지도에 해당하는 ‘의견제시’ 및 ‘권고’는 평균적으로 88%를 차지하고 있었다. 4월과 6월, 10월에는 평균적으로 심의 1건당 2가지 조항을 근거로 제시한 것으로 나타났는데, 이 시기의 행정지도 비율을 보면, 각각 65%와 71%, 70%로 평균 88% 보다 낮으며, 그만큼 법정제재 비율이 높았다는 것을 보여준다. 이는 심의위원회가 위반한 방송내용을 치밀하게 파악하여, 심의 규정 조항들을 적극적으로 적용할 경우, 심의 기준이 강화될 여지가 있음을 보여주는 사례라고 할 것이다. 심의 대상 프로그램들이 가장 자주 위반했다고 판단된 법령은 제14조 ‘객관성’으로 나타났으며, 다음으로 제9조 ‘공정성’을 많이 위반한 것으로 조사되었다. 그러나 보도교양프로그램이 객관적이지 못했다고 판단된 경우, 대부분 행정지도 수준의 ‘의견제시’나 ‘권고’로 의결되었고, 공정성 위반의 경우에도 그 심의 경향은 비슷하게 나타났다. ‘객관성’과 ‘공정성’을 위반한 보도교양프로그램들을 중심으로 어떠한 근거로 행정지도(의견제시, 권고) 조치가 내려졌는지에 대해 알아본 결과, 대부분 정치적인 사안을 다루던 보도과정에서 객관성과 공정성에 문제가 발생하였으며, 심의위원회는 ‘정치적 중요사안을 다루며 명확한 사실 확인절차를 거치치 않은 내용을 방송하여 시청자를 혼동케 한 것’, ‘자료 영상의 출처를 명시하지 않은 채, 시청자가 오인할 수 있는 내용을 전달한 것’, ‘양측의 입장이 첨예하게 다름에도 양측의 입장을 균형 있게 반영하지 않은 것’, ‘취재원 선정의 투명성이 담보되지 않아 사실을 정확하고 객관적인 방법으로 다루지 않은 것’, ‘사회적 쟁점 사안에 대해 개인적 의견을 피력하거나 일방의 입장만을 대변하는 듯한 내용을 방송한 것’, ‘사실관계를 정확히 확인하지 않은 채 특정 사안에 대해 사실과 다른 내용을 방송한 것’ 등이 객관성과 공정성과 관련한 심의규정에 위반되는 것으로 판단하고 있었다. 그럼에도 불구하고 행정지도로 의결한 이유를 보면, ‘위반의 정도 및 유사 심의사례와의 형평성 등을 감안’했다는 것이 가장 큰 이유였으며, ‘방송사가 문제점을 인식하고 반론 내용을 보도하거나 기사를 수정하가나 다시보기 영상을 삭제하는 등 개선의지를 나타냈다는 점등을 감안’ 했다는 등의 근거가 제시되고 있었다. 그러나 이전의 유사 심의사례에 따라 판단한다는 것은 과거 심의위원들에게 그 책임을 돌림으로써 심의자로서의 책임을 회피하는 행위가 될 수 있으며, 이전의 심의결과가 잘못되었는지 여부를 치밀하게 따져보지 않은 채, 그대로 따른다는 것은 심의자로서의 지나치게 소극적인 역할을 하는 것으로 볼 수 있을 것이다. This study analyzed the results of deliberation of the news and cultural education program section of the terrestrial and general service program channel as of the first year after the launch of the 4th Korea Communications Standards Commission. As a result, "opinions" and "recommendations" corresponding to administrative guidance without penalty points accounted for 88% on average. In April, June, and October, on the average, two proposals per review were presented. In this period, the rate of administrative guidance was 65%, 71% and 70%, that is lower than 88% and the rate of statutory sanctions was high. This is an example that shows that there is room for strengthening the deliberation standards when Korea Communications Standards Commission closely grasps the contents of the broadcasting that are violated and actively applies the deliberation regulation provisions. The statutes that were judged to be the most frequent violations of the programs to be deliberated were found to be Article 14, "objectivity", and then to violate Article 9 "fairness". However, when it was judged that the news and cultural education program was not objective, most of them were voted "opinions" or "recommendation" of the level of administrative guidance and the tendency of deliberation was similar in case of fairness violation. Based on what kind of grounds on news and cultural education program that violate objectivity and fairness, about administrative guidance (opinions, recommendation), we found that most of the reports on political issues had objectivity and fairness. The committee decided that it would be necessary for the committee to "confuse viewers by broadcasting contents that did not involve a political confirmation process" and "did not carry out a clear fact-finding procedure that the viewer could be misidentified", "did not reflect the position of both sides in a balanced way, even if the positions of the two sides were sharply different", "did not handle the facts accurately and objectively because the transparency of selecting the sources was not guaranteed", "It is broadcasted contents that express personal opinions about issues or represent only one side"s position", and "the fact that broadcasts of facts and other information about a specific issue without accurately confirming the system" were found to be in violation of the deliberation rules related to objectivity and fairness. Nevertheless, the reason for the decision on administrative guidance was that "considering the degree of violation and equity with similar cases" was the most important reason. "Broadcasters recognized the problem, reported the objection, revised the reporting and the fact that it showed the will to improve such as deleting the video replay". However, judging according to the precedent similar case can be an act of avoiding the responsibility as the deliberative person by turning the responsibility to the past deliberative members, and without considering the precise whether the previous deliberation result is wrong, It can be seen that following the same way plays an overly passive role as a deliberative person.

표면 처리 방법에 따라 칫솔질이 IPS Empress 도재의 외부 stain에 미치는 영향에 대한 분광 측색 방법적 분석

신우진,전영식,한동후,Shin, Woo-Jin,Jeon, Young-Sik,Han, Dong-Hoo 대한치과보철학회 1997 대한치과보철학회지 Vol.35 No.2

The purpose of this study was to evaluate the long term tooth-brushing effect on the color change of specially treated IPS Empress porcelain surface. Staining techique with blue stain and liquid was used. The surfaces of the specimen were treated with 5% and 10% Hydrofluoric acid, 50mm and 250mm alumina sandblast, and then blue stain and liquid were used for external stain. After 29,200, 58,400, 87,600, 116,200 brushing strokes (equivalent to 2, 4, 6, 8 years each), color changes of the stained layer were measured with spectrophotometer(CM-3500d, MINOLTA, Tolkyo, Japan). The result of this study was obtained as follows : 1. The color changes were great after 29,200 tooth brushing strokes in every group, but from 29,200 strokes to 116,800 strokes, there were no significant color changes in each group. (p>0.05) 2. The greastest color changes were observed in 5% HF treated group and the least color changes were observed in $50{\mu}m$ aluminar sandblast treated group in every stroke (p<0.05), but no statistical difference between groups compared with control group (p>0.05). According to these results, pretreatment of I.P.S. Empress porcelain with alumina sandblast improved the color stability It is thought that about 8 year-tooth brushing strokes does not change the color of IPS Empress porcelain significantly on this condition, but long term follow-up will be needed.

국내 제작 Avana 임프란트와 $Br{\aa}nemark$ 임프란트 주위 골조직에 대한 광학 및 형광 현미경학적 연구

한동후,전영식,김진,김선재,Han, Dong-Hoo,Jeon, Young-Sik,Kim, Jin,Kim, Seon-Jae 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.4

The purpose of this study was to compare surface roughness and bone formation around two types of threaded commercially pure titanium implants manufactured by two different companies. The test implants were manufactured by Sumin synthesis dental materials Co. (Avana, Busan, Korea), while the controls were manufactured by Nobel Biocare (MK II, Goteborg, Sweden). To compare bone formation adjacent to newly product implant with $Br{\aa}nemark$ MK II implant, surface roughness was measured by Accurate 1500M and histomorphometric analysis was done. The results were as follows: 1. Measurement of surface roughness showed that Avana implant had a slightly more irregular surface compared with $Br{\aa}nemark$ implant. 2. In the light microscopic studies, no infiltration of inflammatory cells nor the giant cells were observed on both groups. 3. In the light and fluorescent microscopic studies, the amount of osseointegration and the extent and the timing of bone formation were similar. 4. There were no statistically difference between two groups in the average bone to implant con-tacts. Branemark implant; 67% (SD 23%), Avana implant; 70% (SD 16%). Comparing with $Br{\aa}nemark$ implant, Avana implant made of CP grade II titanium showed similar good bone healing, formation and osseointegration.

기능 노출 기간에 따른 골 유착성 임플란트의 촉각 감지도와 최대 교합력의 변화

정복영,전영식,한동후,Jung, Bock-Young,Jeon, Young-Sik,Han, Dong-Hoo 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.1

During the previous several decades the osseointegrated implants have been considered as the most ideal therapy for the fully edentulous or partially edentulous patients. Although the research on the biocompatibility of osseointegration, the oral tactile function, and the histo-neurologic study had been performed, the change of the oral tactile sensibility and maximal occlusal force according to the postinsertion time of implant prostheses has not been studied. The purpose of this study was to compare the oral tactile sensibility and maximal occlusal force of implant pros-theses to natural teeth according to the specific postinsertion time intervals. The fifty seven patients treated with $Br{\aa}nemark$ implants during the recent seven years were involved in this study. The oral tactile sensibility and maximal occlusal force were measured according to the postinsertion time (${\leqq}6\;months,\;{\leqq}12\;{\leqq}\;18\;months\;{\leqq}\;24\;months,\;and\;{\geqq}20\;months$) 1. The passive tactile threshold of implants was higher than 6-7 times when comparing to natural teeth(P<0.05) 2. The absolute pressure threshold in horizontal and vertical direction for the passive tactile sensibility had decreased significantly in the post insertion time 13-18 months group and had increased significantly in the post insertion time over 25 months group (P<0.05) 3. 50% limit thickness and 100% absolute thickness for the active tactile sensibility had decreased significantly in the postinsertion time 7-12 months group ($AT_{50}:P<0.005,\;AT_{100}:P<0.05$) 4. The maximal occlusal force of the implants prostheses had decreased when comparing with natural teeth in the postinsertion time 1-6 months group(P<0.05) and after that there was no significant difference between the implant prostheses and natural teeth(P<0.05) 5. Maximal occlusal force according to the postinsertion time had increased significantly in the 13-18 months group (P<0.05) after that there was no significant difference. 6. There was positive correlation between age and oral tactile sensibility tested in horizontal and vertical direction ($P_{H:r}=0.39,\;P_{v:r}=0.41$) and there was no correlation between age and maximal occlusal force, age and active tactile sensibility 7. According to the results or the questionnaire, 76.6% of the patients were satisfied with the function and 96.7% of the patients were satisfied with the sensibility. In conclusion oral tactile sensibility and maximal occlusal force of implants have changed with the postinsertion time. Oral tactile function of implants was lower than that of the natural teeth, but for the maximal occlusal force there was no difference between implants and natural teeth.