감염 조절용 차단막의 두께가 광중합기의 중합광에 미치는 영향

장훈상,이석련,홍성옥,류현욱,송창규,민경산 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.5

연구목적: 본 연구는 감염 조절용 차단막을 여러 겹으로 사용했을 때 광중합기의 광강도와 파장, light diffusion 등에 미치는 영향에 대해 조사하였다. 연구 재료 및 방법: 감염 조절용 차단막은 투명 랩 (크린랩)을 사용하였고 광중합기는 할로겐 광중합기 (Optilux 360)와 LED 광중합기 (Elipar FreeLight 2)를 사용하였다. 차단막을 1겹, 2겹, 4겹, 8겹으로 광중합기의 광섬유말단을 감싸고 휴대용 광강도 측정기 (Cure Rite)로 광중합기의 광강도를 측정하였다. 광중합기를 주문제작한 optical breadboard에 고정시킨 후 휴대용 spectroradiometer (CS-1000)를 이용하여 광중합기의 파장을 측정하였고, DSLR (Nikon D70s)을 이용하여 광중합기의 light diffusion을 사진 촬영하였다. 결과: 광강도 측정 결과는 차단막의 두께가 증가할수록 광강도가 유의하게 감소하였으나 할로겐 광중합기에서 1겹과 2겹 사이에는 유의차가 없었으며, 4겹 이상의 차단막을 투과할 때 광강도가 더 많이 감소하였다. 여러 겹의 차단막을 투과한 광중합기의 전체적인 파장 형태와 peak wavelength의 변화는 관찰되지 않았다. Light diffusion 사진 촬영 시, LED 광중합기에서는 차단막의 두께가 미치는 영향이 없었으나 할로겐 광중합기에서는 차단막을 4겹 사용했을 때부터 중합광이 조사되는 각도가 감소하기 시작하여 8겹 사용했을 때 통계적으로 유의하게 감소하는 것을 볼 수 있었다 (p < 0.05). 결론: 광중합형 복합레진을 광중합할 경우 감염 조절용 차단막이 찢어지는 경우를 대비하여 1겹으로 사용하기 보다는 2겹으로 사용하는 것이 환자간의 교차감염을 예방하는데 유리할 것으로 사료된다. Objectives: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. Materials and Methods: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eightfold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. Results: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). Conclusions: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

고압 커패시터의 고장 분석을 통한 신뢰도 예측

양석준,김진우,신승우,이희진,신승훈,유동수,장석원 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.6

본 논문은 고압 커패시터의 고장분석과 신뢰성 예측 결과를 다루고 있다. 부품의 수명과 고장률을 예측하기 위해서 두 가지 방법으로 고장 모드와 고장 메커니즘을 연구하였다. 에폭시 수지로 성형된 고압 커패시터가 절연내압 시험 하에서 저항이 제로로 되는 고장에 대하여, 근본원인 고장분석 체계를 효과적으로 수립함으로써 고장 메커니즘의 원인을 분석하였다. 특히 세라믹-에폭시 계면에서의 절연파괴 고장 현상이 강조되었으며, 본 연구에서 얻어진 결과의 타당성은 마그네트론에 장착된 고압 커패시터의 열사이클 시험 수행에 의한 가속시험 결과로부터 입증되었다. 시험 결과들은 결함이 있는 로트를 신속히 규명하고 B10수명을 결정하는데 유용하게 사용할 수 있다. 또한, 유전체의 절연파괴에 대해서 부하-강도 간섭모델을 이용하여 고장률을 예측하였다. This paper presents a result of failure analysis and reliability evaluation for high voltage ceramic capacitors. The failure modes and failure mechanisms were studied in two ways in order to estimate component life and failure rate. The causes of failure mechanisms for zero resistance phenomena under withstanding voltage test in high voltage ceramic capacitors molded by epoxy resin were studied y establishing an effective root cause failure analysis. Particular emphasis was placed on breakdown phenomena at the ceramic-epoxy interface. The validity of the results in this study was confirmed by the results of accelerated testing. Thermal cycling test for high voltage ceramic capacitor mounted on a magnetron were implemented. Delamination between ceramic and epoxy, which might cause electrical short in underlying circuitry, can occur during curing or thermal cycle. The results can be conveniently used to quickly identify defective lots, determine B10 life estimation each lot at the level of inspection, and detect major changes in the vendors processes. Also, thd condition for dielectric breakdown was investigated for the estimation of failure rate with load-strength interference model.

2,3-Disubstituted-4-Oxo-1,2,3,4-Tetrahydroquinazoline 유도체의 합성

이기창,류정욱,이석우,서상균 明知大學校 産業技術硏究所 1987 産業技術硏究所論文集 Vol.6 No.2

2, 3-Disubstituted-4-oxo-1, 2, 3, 4-tetrahydroquinazolines were synthesized by using the isatoic anhydrides and N-substituted-2-aminobenzamides as starting materials. Intermediates were formed by the reaction of isatoic anhydride with primary amines at various conditions. Final products, 2, 3-Disubstituted-4-oxo-1, 2, 3, 4-tetrahydroquinazolines were synthesized by the fusion of pyridine-3-aldehyde with intermediates for 5hrs at various conditions. By using IR, NMR, MS and elementary analysis, each product was identified and yield of 2, 2-disubstituted-4-oxo-1,2,3,4-tetrahydroquinazolines was nearly 80-90%.

CITIS 지원 문서관리 시스템 설계에 대한 연구

정석찬,조장혁,김상균,류병우,오원식,김정훈,최익성 한국경영과학회 1998 한국경영과학회 학술대회논문집 Vol.- No.1

본 연구에서는 일반 기업간에 전자상거래를 지원하기 위한 CITIS(Contractor Integrated Technical Information Service)를 지원하는 문서관리 시스템을 개발하기 위하여, MIL-STD-974의 요구사항과 일반적으로 상용화되어 있는 문서관리 시스템의 기능적 요구 사항을 검토하였다. 이것을 바탕으로 기업간 기술정보 교환의 근간이 될 수 있는 CITIS를 지원하는 문서관리 시스템의 기능을 도출하였다. 조달자인 정부와 공급자인 기업간의 계약에 의한 기술정보 서비스로서의 CITIS 요구사항을 기본으로 하되, 이를 CALS 환경에서 기술정보 서비스에 적용할 수 있도록 개발 요구 사항을 재정립하였다. 일반적인 문서관리 시스템의 기능은 현재 시장에서 상용화되어 있는 PDM 제품의 기능을 분석하여 참조하였다. 한편 CITIS 지원을 위한 부품 구조 관리 기능과 연계를 위하여 문서와 부품 간의 관계가 고려되었으며, 작업흐름관리와의 연동을 위해서는 전자 결재판 개념의 패킷 객체가 고안되었다. 소프트웨어 설계 방법론으로는 객체지향형 소프트웨어 개발 방법론을 채택하여 CITIS 구현을 위한 객체 모델, 동적 모델, 기능 모델을 작성하였다. 소프트웨어 개발 언어는 인터넷 웹 브라우저를 근간으로 활용될 수 있도록 Java를 이용하며, 다른 응용분야와의 손쉬운 통합을 위하여 CORBA 개념을 도입하였다.

마이너리티 차별과 인정 갈등 : 서울시 자치구 비교를 중심으로

김남옥(Kim, Nam-Og),유승호(Ryu, Seoung-Ho),김문조(Kim, Mun-Cho),장안식(Chang, An-Sik),석승혜(Seok, Seung-Hye) 동양사회사상학회 2017 사회사상과 문화 Vol.20 No.2

사회 양극화의 심화에 따라 주요한 갈등의 형태는 분배의 차원에서 인정의 차원으로 확대 재생산되고 있다. 본 연구는 이 같은 한국사회의 갈등 지형의 변화 속에서 무시와 배제의 대상이 되는 마이너리티의 생산동학을 알아보고, 특히 서울시 25개 자치구를 대상으로 이들에 대한 차별 수준을 비교하고자 하였다. 우선 한국사회에서 마이너리티는 결핍, 열등, 취향, 중독의 영역에서 생산되고 있는 것으로 나타나, 마이너리티의 생산이 경제적 영역을 넘어서 문화적 영역으로 확산되고 있음을 확인하였다. 또한 서울시 25개 자치구에서 마이너리티 차별 수준은 알콜중 독자, 트랜스젠더, 게이머가 가장 높았으며, 이는 한국사회의 주요 갈등이 중독이나 취향을 중심으로 형성될 것으로 예측할 수 있다. 좀 더 구체적으로 서울시 자치구의 마이너리티 차별 특성을 분석한 결과, 주로 외국인 노동자의 밀집도가 높은 하층 지역은 상층 지역에 비해 빈곤노인, 새터민, 기초생활 수급자와 같은 결핍집단에 대한 차별이 높은 것으로 나타났다. 이는 과거 빈부간 갈등의 표출로써 결핍집단에 대한 차별은 최근 들어 하층 계급 내부에서 더욱 활발히 이루어지는 것으로 해석된다. 한편, 문화자본이 높은 지역(강남 3구)은 낮은 지역(강북 3구)에 비해 비혼자, 비만인, 키 작은 남자 등과 같은 열등집단과 트랜스 젠더, 오타쿠, 게이머와 같은 취향집단에 대한 차별 수준이 높은 것으로 나타났다. 이는 상층계급 내에서는 인접집단과 경계가 외모나 신체, 취향을 기준으로 형성되고 있음을 의미한다. 이상의 결과는 갑을관계, 루저 등으로 대표되는 한국사회의 갈등이 계급 내부에서 서로 다른 양상으로 전개되며 마이너리티가 생산하고 있음을 보여준다. 이 같은 상황적 계층화가 일반 대중들 다수에게 타당한 것으로 수용될 때 이들에 대한 차별과 배제는 구조적으로 고착화되고 만다. 양극화 사회에서 마이너리티는 일상생활의 모든 국면에서 생산될 수있다는 점에서 갈등관리의 차원을 넘어 근본적인 인정 정의의 차원에서그 해법을 모색할 필요가 있다. As the polarization of society becomes more intense, the types of conflicts are expanded from the dimension of distribution to the dimension of recognition. The minority is the most obvious example of this change. The purpose of this study is to examine the dynamics of minority production in the area of conflicts in Korean society and to compare the discrimination levels of 25 regions(Gu) in Seoul. First of all, minority is produced in the domain of lack, inferiority, taste, and addiction in Korean society. It is confirmed that the production of minority is spreading beyond the economic dimension to the cultural dimension. In addition, among the 25 regions(Gu) in Seoul, the level of minority discrimination was the highest against alcoholics, transgenders and gamers. And, it is revealed that major conflicts in Korean society will be centered on addiction or taste. In more details, discrimination against people such as poor elderly, defectors, and welfare recipients appears to be higher in the poorer regions where foreign workers are concentrated. It is interpreted that the discrimination against the deficient group which was considered as the conflict between the rich and the poor is more prevalent in the lower class recently. On the other hand, regions with high cultural capital (Gangnam 3 gus) show higher levels of discrimination against the groups of inferior such as unmarried, obese, short guy. And also, the discrimination is higher against the groups based on tastes such as transgender, Otaku and gamer. This means that in the upper class, the boundaries between the adjacent groups are formed based on their appearance, body, and taste. The above results show that conflicts in Korean society represented by ‘Gab-eul’ relationship or the politics of loser are spreading in various directions within the class. It also shows that discrimination against ethnic minorities is created in this process. When such situational stratification is properly accommodated by the general public, discrimination and exclusion against them are structured. In a polarized society, in terms of minority peoples can be produced in all aspects of everyday life, the problem of discrimination against minorities needs to be transformed into a more fundamental level of recognitional justice beyond the management of conflicts.

Administration of Radioactive Iodine Therapy Within 1 Year After Total Thyroidectomy Does Not Affect Vocal Function

Ryu, Chang Hwan,Ryu, Junsun,Ryu, Youn Mi,Lee, You Jin,Lee, Eun-Kyung,Kim, Seok-Ki,Kim, Tae-Sung,Kim, Tae Hyun,Lee, Chang Yoon,Park, Seog Yun,Chung, Ki Wook,Jung, Yuh-S. Society of Nuclear Medicine 2015 The Journal of nuclear medicine Vol.56 No.10

<P>The purpose of this study was to evaluate the impact of radioactive iodine therapy (RIT) on vocal function during the early follow-up period after total thyroidectomy (TT) using perceptive and objective measurements, questionnaires regarding subjective symptoms, and data on vocal function in a prospectively enrolled and serially followed thyroid cancer cohort. <B>Methods:</B> Of 212 patients who underwent TT and were screened between January and December 2010 at our hospital, 160 were included in the final analysis. Patients with the following histories were excluded: lateral neck dissection, organic vocal fold disease, external radiotherapy, and voice evaluation during thyroxine withdrawal. Patients were stratified into 3 groups: TT, TT with low-dose RIT (1.1–2.2 GBq), and TT with high-dose RIT (≥3.7 GBq). Voice evaluations were performed before surgery and at 1, 6, and 12 mo after TT. <B>Results:</B> Vocal characteristics were altered after TT, including changes on the grade, roughness, and strain scale; increased amplitude perturbation; decreased fundamental frequency; narrowed pitch range; and global disturbances in subjective functional parameters on the voice handicap index. However, the degree of vocal changes among the 3 groups did not significantly differ within the 1-y postoperative follow-up period. According to the results of subgroup analyses of patients who demonstrated good voice outcomes after TT, there were no significant functional differences among the 3 groups. <B>Conclusion:</B> RIT at any dose does not affect vocal function within 1 y of TT.</P>

Poster Session : PS 1243 ; Pulmonology : Progressive Pulmonary Fibrocystic Changes on Both Upper Lobes in a Patient with Ankylosing Spondylitis

( Do Youn Kim ),( Seok Jeong Lee ),( Yon Ju Ryu ),( Jin Hwa Lee ),( Jung Hyun Chang ),( Yoo Kyung Kim ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Ankylosing spondylitis (AS) is a chronic in. ammatory multisystem disease that primarily affects the axial joints. Pleuropulmonary involvement is an uncommon extraarticular manifestation. There is a wide spectrum in pulmonary parenchyma changes in AS and these changes begin in early stages of the disease and increase with disease duration. These lesions are usually asymptomatic, and in their early stages they are not visible on chest radiographs. We recently experienced a case of advanced AS with progressive pulmonary bullous fibrocystic changes on both upper lobes. The 56-yearold man complained of dyspnea and back pain at the first visit to our hospital eight years ago. He had been diagnosed with AS since he was 27, and he was diagnosed clinically with pulmonary tuberculosis without bacteriological con. rmation 2 years ago before the first visit. He had smoked half a pack of cigarettes daily for 15 years. He was taking nonsteroidal anti-infiammatory agents and he underwent internal fixation of thoracic and lumbar spine due to AS associated spine deformity twelve years ago at other hospital. The initial chest radiograph showed both apical linear fibrotic opacity with cystic changes similar to sequelae of pulmonary tuberculosis. However, over the last 8 years his serial chest radiography and high-resolution computed tomography showed bullous fibrocystic changes on both upper lobes and the findings of progressive increase of bullous cystic sizes correlated with disease duration. During follow-up period, he had suffered from frequent associated pneumonia, exacerbation episode of chronic obstructive airway disorder, and massive hemoptysis due to mycetoma on both upper lungs. Acid-fast staining and all subsequent mycobacterial cultures were negative. To our knowledge, this case is the first in Korea with progressive bullous fi-brocystic changes on both upper lungs as AS associated pleuropulmonary involvement.

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets

Jun, Sang Ho,Park, Chang-Joo,Hwang, Suk-Hyun,Lee, Youn Ki,Zhou, Cong,Jang, Hyon-Seok,Ryu, Jae-Jun Korean Association of Maxillofacial Plastic and Re 2018 Maxillofacial Plastic Reconstructive Surgery Vol.40 No.-

Background: This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically. Methods: Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients. Results: The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg (R = 0.606, P = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery. Conclusions: Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

Design of an Optically Controlled MR-Compatible Active Needle

Seok Chang Ryu,Zhan Fan Quek,Je-Sung Koh,Renaud, Pierre,Black, Richard J.,Moslehi, Behzad,Daniel, Bruce L.,Kyu-Jin Cho,Cutkosky, Mark R. IEEE 2015 IEEE TRANSACTIONS ON ROBOTICS Vol. No.

<P>An active needle is proposed for the development of magnetic resonance imaging (MRI)-guided percutaneous procedures. The needle uses a low-transition-temperature shape memory alloy (LT SMA) wire actuator to produce bending in the distal section of the needle. Actuation is achieved with internal optical heating using laser light transported via optical fibers and side coupled to the LT SMA. A prototype, with a size equivalent to a standard 16-gauge biopsy needle, exhibits significant bending, with a tip deflection of more than 14° in air and 5° in hard tissue. A single-ended optical sensor with a gold-coated tip is developed to measure the curvature independently of temperature. The experimental results in tissue phantoms show that human tissue causes fast heat dissipation from the wire actuator; however, the active needle can compensate for typical targeting errors during prostate biopsy.</P>

Changes of Motor Deactivation Regions in Patients with Intracranial Lesions

Lee, Seung Hwan,Koh, Jun Seok,Ryu, Chang-Woo,Jahng, Geon Ho The Korean Neurosurgical Society 2013 Journal of Korean neurosurgical society Vol.54 No.6

Objective : There is a rich literature confirming the default mode network found compatible with task-induced deactivation regions in normal subjects, but few investigations of alterations of the motor deactivation in patients with intracranial lesions. Therefore, we hypothesized that an intracranial lesion results in abnormal changes in a task-induced deactivation region compared with default mode network, and these changes are associated with specific attributes of allocated regions. Methods : Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) during a motor task were obtained from 27 intracranial lesion patients (mean age, 57.3 years; range 15-78 years) who had various kinds of brain tumors. The BOLD fMRI data for each patient were evaluated to obtain activation or deactivation regions. The distinctive deactivation regions from intracranial lesion patients were evaluated by comparing to the literature reports. Results : There were additive deactivated regions according to intracranial lesions : fusiform gyrus in cavernous hemangioma; lateral occipital gyrus in meningioma; crus cerebri in hemangiopericytoma; globus pallidus, lateral occipital gyrus, caudate nucleus, fusiform gyrus, lingual gyrus, claustrum, substantia nigra, subthalamic nucleus in GBM; fusiform gyrus in metastatic brain tumors. Conclusion : There is increasing interest in human brain function using fMRI. The authors report the brain function migrations and changes that occur in patients with intracranial lesions.