Skin entrance dose for digital and film radiography in Korean dental schools

Cho, Eun-Sang,Choi, Kun-Ho,Kim, Min-Gyu,Lim, Hoi-Jeong,Yoon, Suk-Ja,,Kang, Byung-Cheol 대한구강악안면방사선학회 2005 Imaging Science in Dentistry Vol.35 No.4

Purpose : This study was aimed to compare skin entrance dose of digital radiography with that of film radiography and to show the dose reduction achievement with digital systems at 11 dental schools in Korea. Materials and Methods : Forty six intraoral radiographic systems in 11 dental schools were included in this study. Digital sensors were used in 33 systems and film was used in 13 systems. Researchers and the volunteer visited 11 dental schools in Korea. Researchers asked the radiologic technician (s) at each school to set the exposure parameters and aiming the x-ray tube for the periapical view of the mandibular molar of the volunteer. The skin entrance doses were measured at the same exposure parameters and distance by the technician for each system with a dosimeter (Multi-O-Meter : Unfors instruments, Billdal, Sweden). Results : The median dose was 491.2 μGy for digital radiography and 1,205.0 μGy for film radiography. The skin entrance dose digital radiography was significantly lower than that of film radiography (p<0.05). Conclusion : Fifty-nine percent skin entrance dose reduction with digital periapical radiography was achieved over the film radiography in Korean dental schools.

복강암세포(Sarcoma-180)를 이식한 마우스에서 상황버섯(Phellinus linteus) 추출물이 백혈구 화학주성(Chemotaxis)능에 미치는 영향

조홍식,윤정중,이연태 대한암예방학회 1999 Journal of cancer prevention Vol.4 No.4

재래종 콩 유전자원의 주요 형태적 특성과 변이

윤문섭,백형진,이정란,김행훈,조양희,안종웅,김창영 한국국제농업개발학회 2003 韓國國際農業開發學會誌 Vol.15 No.4

본 실험은 한국, 중국 및 일본 재래종 콩 유전자 자원의 주요형질 변이를 조사하고 이들 자원간의 지리적 유연관계를 비교하고자 수행하였으며, 그 결과를 요약하면 다음과 같다. 1. 경장은 한국(66㎝)이나 일본자원(54.9㎝)보다 중국자원(71㎝)에서 더 컸으며, 또한 변이도 중국자원에서 가장 큰 것으로 나타났다. 2. 개화일수 및 생육일수는 한국자원(65.5일, 151.4일)이 가장 길었으며 중국(57일, 120일)과 일본자원(59.9일, 122.4일)은 같은 경향을 나타냈다. 또한 한국과 중국자원은 지역에 따른 차이를 나타냈으나 일본자원에서는 확인할 수 없었다. 3. 백립중은 한국(18.8g), 일본(17.2g) 및 중국(14.7g) 순으로 무거웠다. 특히 한국자원은 9~11g과 23~25g에서 정점을 나타냈고, 변이폭도 가장 컸다. 반면 일본과 중국자원은 13~17g사이에서 정점을 나타냈다. 4. 협수는 중국(46.9개)이나 일본자원(36.5개)보다 한국자원(75.5개)에서 가장 많았으며, 변이폭도 한국자원에서 가장 컸다. 내도복성은 일본자원에서 가장 강하였다. 5. 정준판별분석결과 can 1을 경계로 하여 오른쪽 상하에 한국재래종이 주로 분포하였고 왼쪽에는 중국과 일본 재래종이 주로 분포하여 각 나라별로 고유한 영역을 가지고 분리되었다. 전체적 경향이 중국과 일본자원이 한국자원보다 가까운 경향을 나타냈다. This experiment was carried out to compare the characters of 944 Korean soybean landraces, 716 Chinese, and 170 Japanese soybean landraces introduced from USDA soybean germplasm collection. Cannonical discriminant and cluster analyses were conducted by their origins. The population from China was taller in plant height than those from Korea and Japan, also its variation was largest in Chinese population. The population from Korea was langer than those from China and Japan in terms of days to flowering and maturity. Also, Korean and Chinese accessions appeared the difference of those traits according to latitude. One hundred seeds weight was in the order of Korean(18.8g), Japanese(17.2g) and Chinese populations(14.7g), especially Korean population was distinguished into two groups; the group including accessions between 10 and 15g, and the other group including accessions between 20 and 25g. However, others showed the peak in range of 13~17g. The number of pod per plant was more in Korean accession(75.5) with the largest variation than Chinese(46.9) and Japanese accession(36.5). The distribution of Korean, Chinese and Japanese accessions reflected the origin of accessions analyzed by cannonical discriminant analysis. The relationship between their geographical origins showed the population of China and Japan are losely related.

교정용 미니 임플랜트 고정원과 SWA en masse sliding retraction 시 전치부 치축 조절 요인에 관한 유한요소해석

정혜심,성상진,문윤식,조영수,임승민 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.5

교정용 미니 임플랜트 고정원을 이용한 교정 치료가 보편화되며, SWA와 이를 이용한 en masse sliding retraction은 임상에서 흔히 사용하는 치료법이 되었다. 그러나 고정원을 성공적으로 보존하려는 노력에 비해, 발치 공간 폐쇄 시 전치부 치축 조절에 관여하는 요인에 대한 보고는 아직까지 부족한 실정이다. 본 연구에서는 제1소구치를 제거한 상악 치아와 치주 인대 그리고 치조골에 대한 3차원 유한요소 기준모델을 제작하였고, 제1대구치와 제2소구치 사이 주호선 10 mm 상방에 식립된 교정용 미니 임플랜트를 고정원으로 사용할 경우, 측절치-견치 사이의 견인 훅의 높이를 변화시키며 후상방 견인력을 가하거나, 주호선에 보상 만곡을 부여하는 것이 전치부 치축 조절에 어떤 영향을 미치는지 시뮬레이션 하였다. 또한 전치부 치축이 설측 경사된 모델을 같은 실험 조건으로 시뮬레이션 하여 발치 공간 폐쇄 시 설측 경사된 전치부 치축을 유지하거나 개선할 수 있는 요인을 검토하였고, 다음과 같은 연구 결과를 얻었다. 2 mm 높이의 견인 훅에 대하여 후상방으로 견인력을 가할 경우 발생하는 함입력으로 인하여 전치부 설측 경사가 더 감소되지는 않았다. 견인 훅의 높이가 5 mm인 경우 후상방 견인력을 가하면, 측절치의 치관 순측 및 치근 설측 이동이 일어나고, 견치의 비조절성 후방 경사 이동이 심화되었다. 4 mm의 보상 만곡은 측절치의 치관 순측 및 치근 설측 이동을 일으키고, 견치의 비조절성 후방 경사 이동을 감소시켰다. 또한 전치부가 설측 경사된 모델을 기준모델과 같은 실험 조건으로 시뮬레이션 한 경우 치근면의 응력 분포와 25000배 확대된 그래프 상에서의 치아 이동 양상은 매우 유사하였다. 이상의 결과는 미니 임플랜트-SWA sliding 생역학을 구사 시 견인 훅의 위치와 와이어 상의 보상 만곡의 유무에 의해 전치부의 치축 조절이 달라지며 실제 임상에서 가이드라인으로 활용될 수 있을 것이다. Objective: With development of the skeletal anchorage system, orthodontic mini-implant (OMI) assisted en masse sliding retraction has become part of general orthodontic treatment. But compared to the emphasis on successful anchorage preparation, the control of anterior teeth axis has not been emphasized enough. Methods: A 3-D finite element Base model of maxillary dental arch and a Lingual tipping model with lingually inclined anterior teeth were constructed. To evaluate factors influencing the axis of anterior teeth when OMI was used as anchorage, models were simulated with 2 mm or 5 mm retraction hooks and/or by the addition of 4 mm of compensating curve (CC) on the main archwire. The stress distribution on the roots and a 25000 times enlarged axis graph were evaluated. Results: Intrusive component of retraction force directed postero-superiorly from the 2 mm height hook did not reduce the lingual tipping of anterior teeth. When hook height was increased to 5 mm, lateral incisor showed crown-labial and root-lingual torque and uncontrolled tipping of the canine was increased. 4 mm of CC added to the main archwire also induced crown-labial and root-lingual torque of the lateral incisor but uncontrolled tipping of the canine was decreased. Lingual tipping model showed very similar results compared with the Base model. Conclusion: The results of this study showed that height of the hook and compensating curve on the main archwire can influence the axis of anterior teeth. These data can be used as guidelines for clinical application.

국제화시대에 부응하는 기술사 자격의 검정방법 개선 방안

조정윤 한국산업교육학회 2001 산업교육연구 Vol.8 No.-

이 연구는 현행 기술사 검정방법에 영향을 주고 있는 제반 문제점을 진단하고, 이를 개선할 수 있는 방법을 모색함으로써, 기술사 자격의 공신력 증대를 통해서 국가경쟁력 및 국제적 통용성 확보에 기여할 수 있는 방안을 마련하는데 목적이 있다. 연구의 수행을 위해서 국가기술자격 검정방법에 대한 현황 및 개선요구사항을 분석하기 위해 문헌조사, 전문가 협의회 그리고 기술사 자격소지자 500명을 대상으로 설문조사를 실시하였다. 현행 기술사 검정방법의 문제로 지적되는 사항은 첫째, 현장실무 중심의 필기 및 면접시험이 마련되어 있지 못하고 있으며 둘째, 자격 신청자의 현장 경험에 대한 적절한 확인과정이 없어 면접시험이 내실있게 운영되고 있지 못하고 있어 셋째, 현장 경력을 적절하게 관리할 컴퓨터화된 체제가 마련되어 있지 못하여 현장경력의 신뢰성이 떨어지고 있다는 것이다. 이러한 기술사 검정방법을 개선하기 위해서는 다음과 같은 조치의 강구가 필요하다. 첫째, 공학교육과 기술사 자격간의 관계, 응시자격, 현장경험 등과 관련하여 국제적인 표준에 부합되도록 현재의 기술사 제도를 개선하여야 한다. 둘째, 필기시험의 내용을 명확하게 제시하여 자격 신청자가 제대로 검정을 준비할 수 있도록 하여야 한다. 셋째, 면접시험 결과의 객관성을 제고하기 위해서 면접시험 질문 요목을 좀더 상세화하고 포트폴리오 작성 등과 같은 방법을 통해서 면접시험을 내실화한다. 넷째, 현장경력 인정에 대한 신뢰성을 높이기 위해서 컴퓨터화된 경력 관리방법을 도입한다. This study aimed to diagnose the problems directly and indirectly affecting the testing method in Professional Engineer Qualification. The ultimate purpose was to provide a blue-print for enhancing national competitiveness through increased authenticity and efficiency of Professional Engineer Qualification in the aspects of responding to globalization. Research methods applied in this study included: review of qualification-related literature, interview with vocational educator and researchers from qualification-related institutes, and a survey of national qualification holders from a variety of professions and industries. The survey samples of 500 persons were drawn from qualification holders nation-wide, and questionnaires were use to analyze the tendency of respondent. Present testing method have problems as follows; First, the Professional Engineer qualification did not have in place an experience-based written examination or an interview system. Second, interviews tended to be superficial because there was no proper confirmation or administration of the applicants' previous field experience. Third, credibility of field experience was not good because there was no computerized system which confirmed and managed field experience records adequately. In order to Improve for testing method of Professional Engineer, we are preparing the following points; First, There was required to be establishes a system to meet the demands of globalization, such as regarding field experiences in terms of an important eligibility, qualifying field experience and linkage between engineering education and professional engineer certification. Second, subject titles needed to be clear and precise so that applicants could prepare for their written examinations accurately informed. Third, interview questions needed to be itemized in a detailed manner for the interview results to be objectively determined, and in order to make the interview a critical stage in acquiring the qualification the qualification procedure needed to be made more intricate through the portfolio method. And then, there was needed to be established a system for educating and training the persons who made questions and participate in the interview as assessor so that they could become familiarized with all the testing method and procedures before they began participating tests. Fourth, in order to raise the credibility of field experience recognition, letters of confirmation of the company and of career, in addition to the existing requirement of the career registration form, should be handed in and computer-managed.

S. mutans의 固定化에 依한 Insoluble glucan의 製造方法 및 齒面 細菌膜 分解酵素인 α-1, 3 glucanase 生産菌珠 Streptomyces SW-522에 關한 硏究

尹廷洹,趙孝相,金成柱 수원대학교 산업기술연구소 1992 산업기술연구소논문집 Vol.7 No.-

In other to investigate α-1, 3 glucanase from microorganisms for hydrolysis of dental caries, S. muatns was immobilized by cubes of 28% polycrylamide and coated with same polyacrylamide. The insoluble glucan obtained 1.13g per one liter in TH medium with 5% sucrose by PA immobilization of S. muatns, which was very pure by IR and TLC analysis. α-1, 3 glucanase produced by of the Strptomyces SW-522, was developed by treatment with 5% EMS. The new Sw-522 M1 strain obtained, which improved activity of α-1, 3 glucanase.

소아청소년 복합만성질환자 수 및 진료비의 변화: 2011-2021년 건강보험청구자료 분석

오정윤,조수진,정진선,조진숙,박춘선 건강보험심사평가원 2023 HIRA RESEARCH Vol.3 No.2

Background: The number of children and adolescents has decreased by more than 3 million over the past 10 years. We analyzed changes in the number of children and adolescents with complex chronic conditions (CCCs) and their medical expenditures between 2011 and 2021. Methods: We used National Health Insurance claims data of patients under the age of 20 from 2011 to 2021. CCCs were classified as pediatric CCCs by Feudtner et al. Patients who repeatedly utilize medical services due to CCCs were defined as patients who sought medical care twice or more within the past 3 years. Their sex, age, CCC categories, and the number of CCC categories were presented using descriptive analyses. Results: The number of children and adolescents with CCCs increased from 345,320 (3.04%) in 2011 to 451,238 (5.33%) in 2021. Patients who repeatedly utilized medical services due to CCCs increased by 71,889 during the same period. The proportion of patients with two or more CCC categories increased from 35.80% in 2011 to 43.67% in 2021. In 2021, patients with other congenital or genetic defect were most common. Medical expenditures associated with CCCs increased from 475,654 million won (12.34%) in 2011 to 768,467 million won (19.11%) in 2021. Conclusion: The number of patients with CCCs and their medical expenditures increased in Korea between 2011 and 2021. The results indicate that consistent national efforts are required to maintain the specialized pediatric care. Further studies are needed to identify pediatric patients who require specialized medical services through various methods.

다중 탐색기반 고속 블록정합 움직임 추정 알고리듬

조영창,최병진,윤정오 경운대학교 산업기술연구소 2000 産業技術硏究論文誌 Vol.3 No.1(B)

Block based fast motion estimation algorithms are based on the assumption that the error in the mean absolute error space monotonically decreases to the global minimum. Therefore, in case of many local minima in a search range we are likely to find local minima instead of the global minimum. This situation is evident in the motion boundary. In this paper we propose the multiple search method. In the proposed method motions are estimated from the many candidate search regions. To reduce the additional search points we reduce the search points using the distance from the initial search point to the recently found vector points. In the simulation the proposed method shows more excellent results than that of other gradient based method especially in the search of motion boundary in PSNR.

反復荷重을 받는 鐵筋콘크리트 내부골조의 履歷특성실험

조용부,윤정배 慶尙大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.13 No.-

The experimental study from interior beam-column joint for RC frames is presented. Test parameters are concrete compressive strength, member flexural strength ratio and joint shear stress, which are the range of critical value for stable behavior. The results from cyclic loading tests show different behaviors with respect to parameters. Further investigations are need for higher concrete strength.

Homomorphic Encryptions at a Long Distance Through Quantum Key Distribution Protocols

JEONG*, Kabgyun,KIM, Yong Jin,YOON, Jong Beom,KIM, Geon Woo,CHO, Gueha,KIM, Suntaek Korean Physical Society 2019 새물리 Vol.69 No.2