지중내 공동 탐지를 위한 비파괴 검사 기법에 대한 실험적 연구

유정동(Jund Dong?Yoo),양학모(Hak Mo?Yang),장기창(Ki Chang?Jang),강승민(Seung Min?Kang),조소현(So Hyun?Cho),김현기(Hyun-Ki?Kim),Seung Soo?Kim,Da Bin?Jin 대한토목학회 2018 대한토목학회 학술대회 Vol.2018 No.10

데이타흐름 시스템에서의 성능평가에 관한 연구

유관종,최종석,신지수,변승환 충남대학교 자연과학연구소 1989 忠南科學硏究誌 Vol.16 No.1

A concept of data flow computer is a radical departure from that of Von Neumann type computers since the central concept of sequential execution is discarded. Data flow model offers an entirely new way of view the execution of program. This paper describes the data flow graph partitioning algorithm for enhancing the efficiency of the data flow architecture which consists of Processing Elements, Distributor, Arbitrator and Global Memory, and evaluate the performance of the proposed data flow system.

모래다짐말뚝의 원심모델링

유남재,정길수,김상진,채승호 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

This paper is results of extensive centrifuge model experiments about design factors influencing the bearing capacity and the settlement behaviors of SCP (Sand Compaction Pile). Centrifuge model tests were carried out changing design factors for SCP method such as replacement area ratio (as= 20, 40, 70%), improvement ratio to footing width (W/B = 1, 2, 3), and amount of fines in sand pile (#200 = 5, 10, 15). Therefore, the effects of these design factors on the bearing capacity and the settlement behavior of SCP were investigated and changes of stress concentratio rato due to such an design factors were also investigated. Centrifuge model testing technique for preparing and installing centrifuge model of sand compaction pile, using freezing them, was also developed. As results of centrifuge model tests, more fines in sand compaction pile increases the bearing capacity of SCP. Optimum improvement ratio to footing width was found to be 2. Values of stress concentration ratio was in the ranges of 1.5 - 3.5. The depth of bulging in sand piles was found in the range of 2.0 - 2.5 times of pile diameter.

Self-etching priming/bonding agent를 이용한 수복에서 microleakage에 관한 연구

유승훈,김종수 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.1

Bonding Agent는 1세대에서 5세대에 거치기까지 많은 발전을 하였고, 최근에는 임상술식과정의 단축에 있어 비약적인 발전을 보였다. 최근에 개발되어 소개된 self-etching pyirning/bonding agent는 6세대 bonding agent로 분류되며, 이를 이용하여 법랑질 및 상아질에 대한 복합 레진의 충전시 발생하는 미세누출을 methylene blue를 이용하여 관찰한 결과, 상아질에서는 기존의 4세대 5세대 접착제와 유의한 차이가 없었으나, 법랑질에서는 6세대 bonding agent가 통계학적으로 높은 미세누출 양상을 보였다. Self-etching priming bonding system was recently developed in order to simplify the clinical skills & save chair time after continuous improvements on dentin bonding agents. To test the magnitude of microleakage of a new "self-etching priming bonding agent" using sound premolar, 4th, 5th, 6th generation dentin bonding agent was applied. Measure the magnitude of infiltration to the gap of enamel-restoration interface and dentin-restoration interface. After bonding of composite resin to sample surfaces according to the manufactures direction and 500 times thermocycling en dwell time 30 second, and microleakage was measured by the ratio of the depth to the axial wall and the magnitude of infiltration. Afterward analyzed by ANOVA test. The result were as follows : 1. Enamel groups showed lesser microleakage (Group Ⅰ, Ⅱ, Ⅲ, Ⅳ) than dentin groups (Group Ⅴ, Ⅵ, Ⅶ, Ⅷ). (p<0.05) 2. There are no statical differences among the dentin groups, in enamel groups, group Ⅳ showed more microleakage than group Ⅰ, Ⅱ, Ⅲ. (p<0.05) For a clinical acceptance, better enamel marginal adaptation is required.

심부정맥혈전에서 조영증강 FISP 기법을 이용한 자기공명술의 유용성

유정현,최수승 梨花女子大學校 醫科大學 醫科學硏究所 1999 EMJ (Ewha medical journal) Vol.22 No.3

Objectives: To demonstrate a number of advantages of Gd-enhanced MR-venography with FISP techinuque in diagnosis of extremity deep vein thrombosis. Method and Materials: Gd-enhanced MR venography with FISP technique was performed in patients had deep venous thrombosis of lower limb. Findngs of MR venography was retrogradely analyzed. Results : Gd-enhanced MR-venography clearly demonstrates venous anatomy of the lower extremities in all cases. And, deep vein thrombosis was well detected with signal void filling defect. MR-venography also shows additional combined findings in deep vein thrombosis. Conclusion : Gd-enhanced MR venography well demonstrates the anatomy of lower extremities and is a useful method for detection of deep vein thrombosis.

과재하중 재하에 따른 역 T형 옹벽의 활동거동에 관한 수치해석

유남재,이명욱,박병수,이승주 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

This paper is experimental and numerical research about the sliding behavior of cantilever retaining walls resisting surcharge loads. In experimental research, centrifuge model tests at the 1g and 40g-level were performed by changing the location of model footing and its width. Bearing capacity of model footing and characteristics of load-settlement and load-lateral displacement of retaining wall were investigated. Test results of bearing capacity were compared with modified jarquio method, based on the limit equilibrium method with elasticity theory. For the numerical analysis, the commericially available program of FLAC was used by implementing the hyperbolic constitutive relationships to compare with test result about load-settlement and load-displacement of retaining wall, bearing capacity of strip footing.

다종의 Pulse Oximeter에서 측정된 산소 분압도의 차이와 상호 비교 결과에 대한 보고

유승훈,김응학,권순원,김종수 대한소아치과학회 2000 大韓小兒齒科學會誌 Vol.27 No.4

진정요법하의 치과치료에서 환자의 상태를 지속적으로 감시하는 것은 매우 중요하다. 여러 방법 중 가장 널리 사용되는 것중 Pulse Oximeter가 있다. Pulse Oximeter는 비침습적 방법으로 계속해서 동맥혈액의 산소포화도를 측정할 수 있도록 고안된 장치로서 기기에 나타나는 산소포화도(SpO₂)는 실제로 측정한 동맥혈액의 산소포화도(SaO₂)와 거의 일치하는 것으로 알려져 있다. 본 진료실에 있는 세종류의 Pulse Oximeter를 이용하여 한 환자에게 동시에 두 개의 기기를 적용하였을 경우, 산출값을 상호 비교한 결과, 짧은(3회) 맥박수를 평균하는 기기가 낮은값이 나왔으며, 다른 두개의 Pulse Oximeter와 유의한 차이가 있는 것으로 밝혀졌다. 짧은 맥박수를 평균하는 기기는 반응이 빠르나, 산소포화도의 값이 작게 산출되고, 외부의 신호에 더욱 민감하여, 오류가 존재할 가능성 또한 높다. 기기의 특성을 알아, 술자는 적절한 기기를 선택하는 것이 중요하다. A major concern in pediatric dentistry is maximizing risk mangement through optimal monitoring of respiratory function during sedation techniques, and Pulse Oximeter is one of the most popular devices for these purpose. Pulse Oximeter is non-invasive device for detecting the sensitive fraction between the saturated & desaturated hemoglobin. Several Studies proved that there is no significant difference between the SpO2 and SaO2 . In this article, We examined three Pulse Oximeter (3300MXR, OX90R, BPM200R). The Pulse Oximeter using shorter pulse beat averaging showed more sensitive reaction to the statue of the patient and lower saturation data. We compared pair of Pulse Oximeter applied to one patient at one time. And BPM200R (using shorter pulse beat averaging) showed statistically low saturation

모 제약회사 근로자들의 직업성 천식 유병률과 약제 분말 노출수준

오성수,최용휴,김은아,이영목,장재길,유장진,박승현,김태균,정수영,김규상,강성규 大韓産業醫學會 2006 대한직업환경의학회지 Vol.18 No.2

목적: 제약회사에서 직업상 천식의 유병 규모를 파악하고 작업공정에 대한 작업환경 측정을 통해 제약회사의 약제 분말에 대한 노출수준을 평가하고자 하였다. 방법: 제약회사에서 약제 분말에 노출되는 근로자를 대상으로 천식을 선별하기 위하여 설문조사 및 진찰, 혈액검사, 폐기능 검사 그리고 피부단자시험을 실시하였고, 각 부서별 공정에 따라서 총분진과 항생제 또는 효소제 분말에 대한 작업환경 측정을 실시하였다. 직업상 천식이 의심되는 근로자에 대하여 기관지과민성에 대한 검사(메타콜린을 이용한 비특이 기관지유발시험)와 약제 분말 기관지유발시험을 실시하여 확진하였다. 결과: 설문조사 및 진찰에서 작업 관련 천식 증상이 있는 근로자는 11명(34.4%)이었고, 약제 분말을 이용한 피부단자시험에서 1+ 이상 반응을 보인 근로자 10명(31.2%)이었다. 비특이 기관지유발시험 결과 8명(25.0%)이 양성(PC20 ≤16 mg/ml)이었다. 약제 분말 기관지유발시험을 통해 직업상 천식으로 확진된 근로자는 5명(15.6%)이었다. 작업환경 측정에서 원료를 충진하거나 투입하는 작업 그리고 정립작업에서 약제 분말에 대한 노출이 많았다. 결론: 제약회사에서 직업상 천식은 주로 제조공정 중 약제 분말에 노출된 근로자에서 발생하여, 증상 및 직업성 천식의 유병률이 높았다. 따라서 원료를 충진 또는 투입하는 작업과 정립작업 등 제조과적에서 약제 분말 노출을 줄이기 위한 세심한 주의가 필요하여, 약제 분말을 취급하는 근로자에 대해서는 천식 증상 조사뿐 아니라 정기적으로 피부단자시험, 비특이 기관지유발시험 등을 실시하여야 할 것이다. Objectives: After the investigation of one worker with occupational asthma, we surveyed the preva- lence of occupational asthma and the exposure level of pharmaceutical dust of 32 workers in a pharmaceutical company. Methods: Thirty-two of the 90 employees participated in the survey which consisted of questionnaire, blood sampling, spirometry and skin prick tests with 8 common allergens as well as 9 antibiotics and 2 enzymes. Various indices of the working environment were also measured. Subjects who had a symptom suggestive of work-related asthma or positive skin prick test were further investigated by PC20 methacholine. Nine subjects who had a PC20 result of 16 mg/ml or less (n=7) or had work-related symptoms and positive skin prick test (n=2) were referred to undergo a specific bronchial provocation test to phar- maceutical dust in an academic allergic disease center. Results: Eleven of 32 workers (34.4%) had a work-related symptom suggestive of occupational asthma. Ten (31.2%) showed positive skin prick test. 8 (25.0%) had a PC20 result of 16 mg/ml or less (indicative of significant bronchial hyperresponsiveness), and 5 (15.6%) had a positive result on the specific bronchial provocation test. Exposure levels of stuffing, input of raw materials and screening process were relatively high. Conclusions: This survey showed that pharmaceutical workers have an increased risk of occupational asthma. Although pharmaceutical factories maintain a relatively good working environment, careful control of respiratory tract exposures, especially during stuffing, input or raw materials and screening process, is important to prevent occupational asthma. Pharmaceutical workers need to undergo regular skin prick and methacholine bronchial provocation tests, as well as asthmatic symptom survey, to ensure the early detection and prevention of occupational asthma.

근기능장치를 이용한 교정 전 치료

김민수,김종수,,유승훈 大韓小兒齒科學會 2005 大韓小兒齒科學會誌 Vol.32 No.4

조기 교정치료의 목적은 현재 존재하는 문제점들을 바로잡고 발생가능한 문제점들을 차단하며 상황이 점점 악화되는 것을 미리 방지하는 것이다. 근기능적인 영향이 치열과 안모성장에 미치는 영향은 정상 치열구조에 형태적 변이를 일으키고 이미 존재하는 부정교합을 가속화시키게 된다. 따라서 이런 근기능적인 영향이 부정교합에 미치는 영향을 조기에 차단하여 부정교합이 악화되는 것을 예방하고 부가적으로 일어날 수 있는 문제점들을 막고자 하였다. 근기능치료는 1960년대 구강 습관을 치료하는 것으로부터 촉진되어 현재까지 많은 장치를 이용한 치료가 시행되고 있다. 최근 기존의 기능적 교정 장치가 가지고 있는 아동에게 적절한 장치로 Pre-orthodontic TRAINER가 소개되었다. Pre-orthodontic TRAINER는 6~10세 영구 전치가 맹출한 혼합 치열기 어린이에서 특히 하악 전치부 밀집이나, 전치부 반대교합, 2급 부정교합, 과개 교합을 가졌을 경우 사용될 수 있다. 또 만성적인 구호흡이나 손가락 빨기 버릇, 잘못된 연하습관을 가진 어린이에게도 유용하게 사용 될 수 있다. 본 증례는 단국대학교 소아치과에 교정치료를 하기 위해 내원한 환자들 중에서 본격적인 교정치료 시작 전 습관조절을 위해 Pre-orthodontic TRAINER를 이용하여 만족할 만한 결과를 얻었기에 보고하는 바이다. The purposes of early orthodontic intervention are to correct obvious problems, to intercept developing problems and prevent them from becoming worse. Myofunctional influence on facial growth and the dentition change in muscle function and initiate morphologic variation in the normal configuration of the teeth and enhance an already existing malocclusion. Myofunctional therapy has been advocated since 1960's as the treatment for tongue thrust and other oral habits. Pre-orthodontic TRAINER is introduced as functional device usable in children of mixed dentition to correct functional problems concerning soft tissue, tooth and skeleton. The most common cases to treat with Pre-ortho-dontic TRAINER are lower anterior crowding, anterior open bite, Class Ⅱmalocclusion and deep bite. Also, it can be used as correction of oral habits. Patients in this cases visited Department of Pediatric Dentistry, School of dentistry, Dankook University for orthodontic treatment. Pre-orthodontic treatment with Pre-orthodontic TRAINER was carried out for correction of the oral habits.

Langmuir-Blodgett막 MIM소자의 전도 특성

권영수,유승엽 東亞大學校 附設 情報通信硏究所 1997 情報通信硏究所論文誌 Vol.5 No.1

Langmuir-Blodgett (LB) method have been used by many researcher because of its facility to control the thickness of film as molecular order and orientation of molecular. We fabricated MIM device using maleate copolymer LB films(2C??MA-VA-VE₂) and electrical conduction mechanism in ultra-thin LB film were investigated. In our experimental results, the maleate copolymer LB film have the property of insulator like organic ultra-thin film. Its dielectric constant were about 4.0∼6.0 by I-V measurement and frequency-capacitance measurement. Schottky current was appeared as electrical conduction current and Schottky barrier was about 0.9[eV]