구내 골신장술 후 식립된 전치부 임플란트보철 치험보고

김한석,김명래,이성근,강상원,김기환,김형섭 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.1

Objective : This is to report the effectiveness of intraoral distraction osteogenesis for alveolar augmentation in the extremely atrophied alveolar defects and to review the clinical results of the 2 cases. Subjects and Methods : Anterior segmental osteotomy was performed and the trans-oral alveolar distractors(Martin, Germany) were applied in 2 patients with the severe acquired anterior maxillary and mandibular defect. After latent period for 1 week, the osteomized alveolar segments were distracted by 1 ㎜ a day (0.5 ㎜/l turn) for 8 days in case Ⅰ and 0.6 ㎜ a day(0.3 ㎜/l turn) for 10 days in case Ⅱ. The consolidation period was about 8 weeks in each case. Thereafter, 6 titanium threaded implants(Branemark, Restore) were simultaneously installed with removal of distractor. The implants were tested clinically and radiographically. Results : Amounts of acquired alveolar bone were 8 ㎜ in case Ⅰ and 6 ㎜ in case Ⅱ respectively, with the increased width of the ridge crests and soft tissue expansion. Dental implants installated on the augmented alveolar ridges in 8 weeks after distrction were confirmed as in good osseointegration and in good function without any complications. Conclusion : Intraoral distraction osteogenesis can be a good option for alveolar ridge augmentation of the severely atrophied ridges and soft-tissue defects. However, for the better vector control of distracting segments and for anterior esthetics, customized distraction devices could be considered later.

고속 주차시스템 개발에 관한 연구

김순철,박선국,김한근 慶南專門大學 2001 論文集 Vol.29 No.1

벡터제어에 의한 선형 유도전동기의 운전특성

김순철,김한근,신동율,정귀상 東西大學校 1998 동서논문집 Vol.4 No.-

The control of PWM Inverter-Fed SLIM(Single-sided Linear Induction Motor) is achieved with Vector control and PI control. In the manufacture line. SLIM used to the conveyance machine has required to the quick response and the constant operating without trembling when the goods convey. So, the speed control and the thrust control must be achived, and the trembling of air gap length which is occured between the primary winding core and the secondary structure of the SLIM must be restricted. First, voltage equations of SLIM is calculated from the proposed equivalent in this paper and the exciting current and the thrust component is gotten from its. Its modeling and analysis are able to control robust transient thrust from the current regulation when SLIM drive. These results exemplified a capacity by the direct drive of SLIM used to the conveyance.

2종의 Ferrite가 혼합된 페라이트/ 고무 복합형 전파흡수체의 전파흡수특성

김한근,이수호,손무헌,박정학,사공 건 東亞大學校 1997 東亞論叢 Vol.34 No.-

In this study, the ferrite/rubber composite microwave absorbers mixed Ni-Zn ferrite and Ni₂Y ferroxplanna were prepared in order to control matching condition. The variation of the material constants(ε*, μ*) and microwave absorbing characteristics were investigated with various ferrite mixing ratio. The material constants of ferrite/rubber composite microwave absorber could be controlled by variation ferrite mixing ratio.

合成溫度에 따른 濕式 Ni-Zn Ferrite 입자의 크기

金漢根,司空鍵 東亞大學校 1991 東亞論叢 Vol.28 No.1

Formation of Ni-Zn ferrite powders by wet direct method and its change of particle size dependent on the calcined temperature of the coprecipitates were examined. The coprecipitates were prepared by adding alkaline solution into the constituent metal ions solution, and subsequent heat treatments. At 150(℃ ), the particles were ultrafine spherical shaped particles of about 500(Å) in diameter and the particle size of Ni-Zn ferrite obtained by the wet direct method could be arranged from 700(Å) to 1450(Å) by changing the calcined temperature(400, 600, 700 and 1,000(℃ )) of the coprecipitates.

광대역형 Ferrite/Rubber 복합형 전파흡수체의 제작 및 특성

김한근,김삼룡,사공건 東亞大學校 1996 東亞論叢 Vol.33 No.-

In this paper, the microwave absorption properties of two layered absorber were evaluated. The two layer absorber were composed of Ni-Zn ferrite/rubber and Ferroxplana/rubber absorber. The excellent absorption properties of the two layered absorber were shown that the transforming layer was Ferroxplana/rubber absorber and the absorbing layer was Ni-Zn ferrite/ rubber absorber and that the optimal thickness of transforming and absorbing layer were 4 and 1(mm), respectively.

Ni-Zn Ferrite/Rubber복합형 전파흡수체의 정합조건 설계

김한근,사공건,신광호 東亞大學校 1994 東亞論叢 Vol.31 No.1

The demands for microwave absorbing materials and designs are being increased. We have studied about a new design technique to seek for the matching conditions for composite absorbers. The ferrite/rubber composite microwave absorbers were fabricated with Ni-Zn ferrite prepared by coprzcipitation method and silicone rubber. We have figured out the matching conditions(frequency and thickness) through the material constants of the self-maded ferrite/rubber composite absorber by utilizing the matching map and the matching boundary map. We could make a prediction for the matching conditions of ferrite/rubber composite absorber with our developed design technique.

인산 칼슘을 사용한 수산화아파타이트 시멘트의 응결·경화 특성에 관한 연구

김한엽,박찬근,송태웅 경남대학교 신소재연구소 1996 論文集 Vol.6 No.-

습식법이나 수열법으로 합성한 hydroxyapatite(HAp)의 분말을 성형, 열처리한 소결체는 지금까지 알려진 바이오 세라믹스 중 생체친화성이 가장 우수한 것으로 입증되고 있으나 소결에 따르는 제조상의 몇가지 문제점을 안고 있다. 본 연구에서는 소결에 의하지 않고 tetracalcium phosphate(TTCP)분말과 dicalcium phosphate dihydrate(DCPD) 분말의 혼합물로 만든 paste를 용해·침전반응으로 응결·경화시켜 직접 HAp 경화체를 얻고, 이때 몇가지 변수가 HAp의 생성과 응결 및 경화특성에 미치는 영향을 검토하였다. TTCP와 DCPD로 조합한 시멘트의 수화반응생성물은 HAp 경화체였으며 이의 미소결정의 interlocking에 의해 응결·경화 하였다. 반응온도 및 HAp 종자의 첨가는 주로 초기단계의 반응속도에 영향을 주었다. 50℃에서의 HAp 생성 반응은 24시간 이내에 거의 완료되었다. Hydroxyapatite ceramics, one of the excellent biocompatible materials, are usually prepared by sintering of hydroxyapatite powders from wet chemical methods. But some problems caused by sintering process are still remained. In this study, instead of powder sintering methods. hardened bodies of hydroxyapatite were prepared by self-hardening reaction of cement paste composed of powdered tetracalcium phosphate(TTCP) and dicalcium phosphate dihydrate(DCPD). Some effects of seeding, reaction temperature on setting and hardening properties were investigated . The hydration products of the hardened paste were composed of finely-crystallized hydroxyapatite which causes setting and hardening by interlocking themselves. Self setting and hardening reaction are accelerated by elevating reaction temperature and addition of hydroxyapatite powders as a seeding materials. The hydration reaction of the paste. at 50C. was nearly finished within 24 hours after mixing with water.

방사선 조사에 의한 흰주 난포의 퇴축과 난포세포의 방사선 감수성

김수일,한승로,조근자,허대영,이영호,조문준,김무강,김원식 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

The aim of this study were to investigate radiation-induced atresia and radiation susceptibility in the rat ovary morphologically. Female rats (Sprague Dawley strain) of 4 weeks old were irradiated with dose of 4 Gy and 8 Gy, and sacrificed at hour 6, 12, and 24 after radiation. The H & E stain, the TUNEL method (ApopTag kit) and transmission electron microscopy (TEM) were used. In light microscopic observation, the number of atresia of ovarian follicles were increased significantly at 6h after irradiation (p<0.01). There was no significant difference between 4 Gy and 8 Gy irradiated groups. In TEM observation, granulosa cells in radio-sensitive follicles were characterized by several structural features including condensation of nuclear chromatin granules, nuclear fragmentation and apoptotic body formation. An apoptotic cell is observed to have been phagocytosed by a normal granulosa cell. Granulosa cells in radio-resistant follicles were characterized by several structural features including nuclear indentation, partial condensation of chromatin granules, mitochondrial swelling, dilatation of RER cisterns, accumulation of dense irregular masses, accumulation of lipid droplets, and increased lysosomal bodies. Number of gap junctions between granulosa cells were decreased, and intercellular space were widen than that of control animals. These findings were prominent at 6h after irradiation and were diminished at 12h and 24h after irradiation. With these results, it was concluded that radiation-induced follicular cell apoptosis and ovarian follicular atresia in rat ovary increased considerably at 6h after irradiation. Further studies are needed to reveal the more extensive differences between radiosensitive and radioresistant follicular granulosa cells.

웹페이지 체류시간을 활용한 성향분석 시스템의 설계 및 구현

김창근,탁한호,송태섭 진주산업대학교 농업기술연구소 2007 農業技術硏究所報 Vol.20 No.-

If web users visit highly attractive pages during the navigation pattern, they spend more time over viewing and visiting the pages. This can be important information for electric commerce as well as for website owners to analyze what web sufferer’s tastes are. This paper is designated to find out sufferer’s precise taste by estimating how much time sufferers’ spent in certain sites that they have visited.