Clean Room위험성 평가에 따른 안전성 확보에 관한 연구

송윤석,윤명오,윤여송,김성민 한국화재소방학회 2003 한국화재소방학회 학술대회 논문집 Vol.2003 No.추계

알칼리와 열처리에 의한 임플란트의 표면 특성 및 골유착 안정성에 관한 연구

송윤석,조인호,Song, Yun-Seok,Cho, In-Ho 대한치과보철학회 2008 대한치과보철학회지 Vol.46 No.5

생체 활성 재료는 생체 내에서 자가적으로 인회석 층 (apatite layer)을 형성하여, 골과의 생화학적 결합이 가능해야 한다. 알칼리와 열처리를 통하여 생체 활성 표면을 얻을 수 있는 것으로 보고되고 있다. 본 실험에서는 알칼리 및 열처리를 시행한 임플란트들의 안정성을 평가하고자 하였다. 실험군의 분류로 1군은 대조군인 선반 가공 임플란트군, 2, 3군은 $60^{\circ}C$, 5 M의 NaOH 용액에 24시간 처리한 후, 각각 대기 중 및 진공 상태 $600^{\circ}C$에서 1시간 동안 열처리하였다. 처리된 시편은 FESEM, XPS, TF-XRD 및 AFM을 이용하여 표면 특성을 관찰하고, 임플란트의 안정성을 위해 공진 주파수와 페리오테스트 및 역 토오크를 측정하고, 골유착 안정성에 관한 차이를 비교 분석하여 다음과 같은 결과를 얻었다. 1. 표면 특성: 알칼리 및 열처리를 시행한 2, 3군은 비슷한 양상의 거친 표면을 보여주었다. 알칼리 처리를 시행한 2군과 3군에서 1군과는 달리 높은 함량의 나트륨 이온이 검출되었으며, 결정구조 분석 결과 2군에서 예추석 (antase)과 금홍석 (rutile)이 혼재된 상태로 금홍석이 우세한 양상을 보여주었다. 2. 공진 주파수 분석: 군간 비교에서 12주에 2군이 1, 3군에 비해 통계적으로 유의하게 높은 측정치를 보였다. 주간 비교시, 1, 2군은 4주 이후에 유의한 증가를 보여주었고, 3군은 2주와 4주에서 각각 유의한 증가를 보여주었다 (P < .05). 3. 페리오테스트 분석: 주간 비교에서 1, 2군은 4주 이후에 유의하게 감소를, 3군은 2주와 4주에서 각각 유의한 감소를 보여주었다 (P< .05). 4. 역 토오크 분석: 군간 비교에서는 2, 4, 8주에서는 2군이 1, 3군에 비해 유의하게 높은 측정값을 보여주었다. 주간 비교에서는 1, 3군은 4주, 12주에서 유의한 증가를 보여주었고, 2군은 4주부터 유의한 증가를 보여주었다 (P < .05). 이상의 결과로 볼 때, 알칼리 및 대기 중 열처리를 통해서 적절한 결정 구조의 산화막을 가진 생체 활성화된 무정형의 나트륨 티탄산염 층을 얻을 수 있었고, 알칼리 및 진공 상태 열처리만으로도 나트륨이 함유된 생체 활성화된 표면을 얻을 수 있었다고 사료된다. 또한 이런 처리 과정으로 형성된 표면층들은 임플란트의 초기 골유착에 도움을 줄 수 있는 유용한 방법 중 하나라고 사료된다. Statement of problem: Bioactive materials must have the ability to spontaneously form a bone like apatite layer on their surface and induce direct biochemical bonding to bone. A simple chemical treatment via alkali and heat has been revealed to induce bioactivity in titanium. Purpose: The purpose of this study was to evaluate the surface characteristics and stability of alkali and heat treated implants. Material and methods: Specimens were divided into three groups; group 1 was the control group with machined surface implants, groups 2 and 3 were treated with alkali solutions and heat treated in the atmosphere and vacuum conditions respectively. The surface characteristics were observed with FESEM, XPS, TF-XRD and AFM. Stability was evaluated with the resonance frequency analysis, periotest and removal torque values. One-way ANOVA and Duncan test were used for statistical analysis. Results: 1. Groups treated with alkali and heat showed similar characteristics. Groups 2 and 3 showed high compositions of Na ions on the surface with sub-micron sized pores compared to group 1. Group 2 showed mixed compositions of anatase and rutile with superior contents of rutile. 2. Resonance frequency analysis : The ISQ of group 2 showed significantly higher values than that of groups 1 and 3 at 12 weeks. The ISQ of groups 1 and 2 showed significant increase after 4 weeks, and the ISQ of group 3 increased significantly after 2 and 4 weeks respectively (P < .05). 3. Periotest: The PTV of groups 1 and 2 showed significant decrease after 4 weeks, and the PTV of group 3 showed significant decrease after 2 and 4 weeks respectively (P < .05). 4. Removal torque analysis: The removal torque value of group 2 was significantly higher than those of groups 1 and 3 at 2, 4 and 8 weeks. The removal torque values of groups 1 and 3 showed increase at 4 and 12 weeks, but the removal torque value of group 2 showed increase after 4 weeks (P < .05). Conclusion: An oxide layer with appropriate crystal structure and amorphous sodium titanate layer can be obtained on titanium implants through alkali and heat treatment in the atmosphere, and even alkali and heat treatment in vacuum conditions, provided a bioactive surface containing sodium. These surface layers can be considered to be effective for enhancement of osseointegration and reduction of healing period for implant treatment.

肢體不自由學生들의 體育 活動에 대한 關心度 硏究 : Chiefly on students of special schools or rehabilitation centers

姜東洹,宋胤碩 慶熙大學校 體育科學大學 1991 體育科學論叢 Vol.- No.4

In the present study, with the 300 subjects of elementary, middle, and high school disabled students attending special schools or rehabilitation centers, the condition of their activities in the school hours of physical education, their degree of concern, and the realities of tools and facilities for their physical education were inspected. For data analysis, some questionaires were utilized, the collected data were inputted to the computer, and percentages for each item respectively in the questionnarire were conclulated. Conclusions from data analysis are as follows: 1. With regard to cause of the disabled, most students has suffered from postnatal diseasesm and unexpected accidents rather then the inborn disabled, and the most effected period of such an attack was babyhood before attending school. This suggests that since babyhood is a period when babies not prefect physically, parents at home should concern with their baby's health as well as the common sense of preventive medicine. 2. With regard to the sports events practiced in the school hours of physical education, male students had ball games mostly and female students team-sports events. However, the development of proper physical education programs and securement of physical education facilitntsies should be researched and achieved so that all the students can participate in such sports events positively. 3. With regard to their degree of satisfaction in learning physical education, it appeared that they seemed to be satisfied in general and wait with interest in receiving physical education school hours. 4. It seemed to me that they recognized the necessity of physical education and received it affirmatively. 5. It appeared that the activities of physical education had much helped their physical strength and health. 6. It appeared that most of them thought that the facilities of physical education were short. Therefore, based on such findngs from the present study, since the disabled students try to find a way of rehabilitation as cultivating their spiritual and physical ability by means of the improvment of their health and physical power through the activities of physical education, in order to activate the learning of physical education, it is considered that rearing of the leaders of physical education for the disabled and the development of physical education programs and its facilties, much investment and study are absolutely necessary.

한국 재난관리조직의 연구내용 분석

송윤석 국가위기관리학회 2011 국가위기관리학회 학술대회 Vol.2011 No.1

자외선 차단제가 악안면 실리콘의 색변화에 미치는 영향에 관한 연구

송윤석,임주환,조인호,Song, Yun-Seok,Lim, Ju-Hwan,Cho, In-Ho 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.3

The color change of maxillofacial silicone has been attributed to certain environmental factors such as exposure to the UV component of natural sunlight, wetting and drying of the elastomer and surface abrasion resulting from the application and removal of cosmetics. The purpose of this study was to evaluate the color change of maxillofacial silicone (Silastic MDX4-4210) according to type of pigment (cadmium yellow, titanium white, cosmetic red), and UV absorber application method after 200, 400, and 600 hours of 350nm UV light irradiation. The results were as follows. 1. According to type of pigments, after 200 hours cosmetic red showed significantly larger color change than cadmium yellow and titanium white, and after 400 and 600 hours color change significantly decreased in the order of cosmetic red, cadmium yellow, and titanium white (p<0.05). 2. In the cadmium yellow group, after 200 hours, the non-treatment group showed significantly larger color change, but after 400 and 600 hours, color change significantly decreased in the order of non-treatment, surface application and mixed group (p<0.05). 3. In the titanium white group, there was no significant color change difference between the three groups after 200 and 400 hours, but after 600 hours, the mixed group showed significantly smalt or color change than the non-treatment and surface application groups (p<0.05). 4. In the cosmetic red group, there was significant decrease in color change in the order of non-treatment, surface application and mixed group (p<0.05). From the results above, the effect of UV light absorber differed according to the type of pigment, but mixing UV light absorber with maxillofacial silicone is thought to give superior resistance against UV light irradiation in the long run.

다중이용업소의 제도개선 방안에 관한 연구

송윤석,현성호,윤명오 한국화재소방학회 2005 한국화재소방학회논문지 Vol.19 No.4

This study has investigated problem that fire damage and a loss of lives increased continuously in spite of improvement countermeasure enforced since fire accident of multiplex available premises, and has analyzed problem and weakness factor through question investigation in fire prevention administration by space of multiplex available premises and special quality business form. We have proposed institutional improvement of efficient multiplex available premises studying fire fighting safety education and training way about employer or employee with specification of fire prevention administration system, on the basis of such analysis. 본 논문에서는 다중이용업소의 화재사고 이후 시행된 개선대책에도 불구하고 화재발생과 인명피해가 지속적으로 증가하는 근원적인 문제점이 무엇인지를 조사하였고, 다중이용업소의 공간 및 영업형태적 특성에 따른 방화관리측면에서 문제점 및 취약요인을 설문조사를 통하여 분석하였다. 이와 같은 분석을 토대로 방화관리체제의 명확화, 업주 또는 직원 등 관계인에 대한 소방안전교육 및 훈련 방안 등을 연구하여 효율적인 다중이용업소의 제도개선 방안을 제안하였다.

HEVC-기반 3차원 비디오 부호화에서 깊이 모델링 간소화 방법

송윤석,호요성,Song, Yunseok,Ho, Yo-Sung 한국스마트미디어학회 2013 스마트미디어저널 Vol.2 No.2

본 논문에서는 최근 3D-HEVC 표준화 작업에서 평가 중인 깊이 모델링 모드(DMM: depth modeling modes) 기술의 복잡도를 줄이는 방법을 제안한다. DMM은 HEVC의 인트라 예측에 네 개 모드를 추가하여 깊이 영상에서 객체의 에지를 정확하게 표현하기 위한 기술이다. 특히, 모드 3은 이미 정의되어 있는 다수의 웨지렛(wedgelet) 후보들로부터 왜곡값을 계산해야 하기 때문에 복잡도가 높다. 제안하는 방법에서는 참조 블록의 각 변에서 인접 화소의 절대값 차를 이용해 화소값이 급격히 변화하는 위치를 찾는다. 이를 기반으로 웨지렛 후보의 수를 6개로 줄여 불필요한 웨지렛 왜곡강 계산은 생략했다. 모의실험을 통해 제안하는 방법이 부호화 성능은 유지하면서 평균 3.1%의 복잡도 줄임을 보였다. In this paper, we present a method to reduce complexity of depth modeling modes (DMM) that are used in the current 3D-HEVC standardization. DMM adds four modes to the existing HEVC intra prediction modes for accurate object edge representation in the depth map. Especially, Mode 3 requires distortion calculation of numerous pre-defined wedgelets, inducing high complexity. The proposed method employs absolute differences of neighboring pixels in the sides of the reference block to find high intensity changing positions. Based on such positions, the number of wedgelet candidates is reduced to six and distortion calculation is skipped for irrelevant wedgelets. Experimental results show complexity reduction by 3.1% on average, while maintaining similar coding performance.

대도시 재난관리체계의 유형별 효율화 비교분석

송윤석 국가위기관리학회 2010 국가위기관리학회 학술대회 Vol.2010 No.1

대도시 재난관리체계의 유형별 효율화 비교분석

송윤석 위기관리 이론과 실천 2010 위기관리 이론과 실천 세미나발표논문집 Vol.2010 No.-

Clean Room 위험성 평가에 따른 안전성 확보에 관한 연구

송윤석,윤명오,현성호,이창우,윤여송,김성민 한국화재소방학회 2004 한국화재소방학회논문지 Vol.18 No.4

This research analyzes Clean Room accidents, and presents research Clean Room, major fire prevention standards of Clean Room (FM, IRI, and NFPA Code), various results from Fire Simulation of analysis. The results are : the smoke diffusion is very quick coupled with the Heating, Ventilating, and Air Conditioning (HVAC) systems under fire ; the possibility of getting the result and the possibility the role of the Sprinkler systems to reduce the diffusion of the smoke. We learn about the importance to stop operating Heating, Ventilating, and Air Conditioning (HVAC) systems and to operate the Sprinkler system for securing safety with fire detection. Therefore, This research will be contributing to secure safety of Clean Room. 본 연구에서 Clean Room 재해사례를 분석하였고, Factory Mutual Property Loss Prevention Data Sheets(FM), Industrial Risk Insurers(IRI), NFPA Code 등의 Clean Room 설계 주요 방화기준에 대하 여 비교분석을 하였다. 그리고 화재시뮬레이션을 통한 위험성 평가를 통해서 화재 시 공조설비의 작동 으로 인한 연기산란 현상으로 Clean Room 내의 피해규모가 상상을 초월하는 결과를 얻을 수 있었으며, 또한 스프링클러설비의 작동으로 열온도가 더 낮아지고, 연기의 확산속도를 더 줄여줄 수 있는 것으로 분 석되었다. 따라서, Clean Room 내의 화재 시 화재감지기에 의해 공조설비를 정지시키고, 스프링클러설비 를 설치하는 것이 안전성을 확보하는데 중요한 요소임을 유추하였다. 그러므로 본 연구에서 Clean Room 에 대한 안전성을 확보하는데 기여하고자 한다.