http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Hun Ju Yun (검색결과 450 건)
- 무료
- 기관 내 무료
- 유료
-
조수헌,하미나,한상환,주영수,성주헌,강종원,윤덕로,송동빈,이명학,김선태 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.2
To determine the recovery time from noise-induced temporary threshold shift(TTS), a prospective field study was conducted at three worksites where workers are known to be exposed high level of noise. Subjects were selected according to answers on a questionnaire which inquired about otological history and previous noise exposure, including avocational, military and occupational exposures. After excluding employee with past otologic problems, recent exposure to high level noise, and under medications, total 92 employees participated in the study. Among 92 participants, complete consecutive audiometric examinations were carried out at 0∼2 hours, 5∼7 hours, 14∼16 hours after worktime noise exposure on 26 participants wearing hearing protectors and 22 participants wearing no protective devices. The difference between the hearing level 0∼2 hours after noise exposure and 5∼7 hours is statistically significant by paired t-test(p<0.01). The median recovery times calculated from the data of 22 participants wearing no protective hearing devices are 15.6 hours at 4000Hz, and 7.7 hours, 10.3 hours, 8.4 hours at 1000Hz, 2000Hz and 8000Hz respectively. These data suggest that when measuring the pure tone audiometry for noise exposed workers, at least 16 hours noise-free interval is required.
-
고정훈,조동우,윤원수,김주한 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-
In most of the existing mechanistic models, the cutting process simulation is often restricted to a single path machining operation under a fixed cutting condition. Complex cutting processes such as die or mold manufacturing, however, are performed under two- or three-dimensional multiple tool paths. Since the tool paths in CNC machining are composed of line and arc segments, transient cuts are frequently occured due to the multiple paths. Even in steady cuts, the width of cut is varied with each segment. In this regard, this paper deals with the development of process simulation system for transient cuts, where continuously changing cutting configuration is computed, and then the cutting forces are predicted.
-
김재환,김성홍,윤헌주 광운대학교 신기술연구소 1998 신기술연구소논문집 Vol.27 No.-
절연체 내부의 보이드로 인하여 부분방전이 발생하면 국부파괴와 완전절연파괴의 원인이 된다. 부분방전으로 생기는 트리잉은 절연재료를 열화 시키고 절연 수명을 단축시키는 중요한 원인이 되므로 절연파괴를 미연에 감지하여 절연재료 수명을 예측할 수 있는방법에 대한 연구는 매우 중요하다. 이러한 관점에서 본 연구는 부분방전 및 음향방출 감지 시스템을 이용한 컴퓨터 감지 시스템을 개발하여 각시스템의 장점을 이용함으로써 열화진단을 실시하였다. 부분방전 감지 시스템의 장점은 음향에 비하여 검출 신호가 양호하고. 고전압 절연 장치의 신뢰성을 평가하기에 적합하다. 또한 음향방출 감지 시스템의 장점은 전자기의영향을 받지 않고, 열화 과정을 실시간으로 관찰할수 있다는 것이다. 이 두 가지의 장점을 복합적으로 이용하면 절연재료 내부에서 발생하는 트리의 위치와 부분방전을 효과적으로 감지할 수 있다. 열화 분석 방법으로 먼저 부분방전 펄스와 음향방출 펄스를 회귀분석하여 T검정에 의한 상관계수와 결정계수를 구하여 비교해본 결과 부분방전과 음향방출 펄스는 대체적으로 비슷한 형태를 보였다. 이것은 Yoshimura와 Fuitta의 연구 결과와 일치하였다. The partial discharge that occurs due to internal voids. usually causes local breakdown or may lead to entire breakdown of insulation. Treeing due to PD is one of the main causes of breakdown of the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation has become important. From this viewpoint, our studies diagnose insulation degradation using the method of computer sensing system, which has the advantages of PD and acoustic emission(AE) sensing system To use advantages of these two methods can be used effectively to search for treeing location and PD in some materials. To evaluate the degree of degradation. we analysed the PD pulses and AE pulses by regression analysis. compared these obtained correlation coefficients with determination coefficients by T-distribution and found that PD and AE pulses show a similar pattern on the whole. This is in agreement with the results of the research by Yoshimura and Fujita.
-
하은희,조수헌,김선민,주영수,한상환,하미나,권호장,홍윤철,김창엽 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.1
Group occupational health service programme started in 1990 is one of the measures to cope with limited human and financial resources in occupational health. The programme has expanded rapidly to include 52 institutions, private as well as public, all over the country. In spite of its potential impact on health of employees and practice of occupational health in small and medium sized industries, comprehensive evaluation in terms of quality has not been tried. This study has aims to develop the criteria to assess the quality of newly developed group occupational health service programme, and to investigate the quality of institutions, and finally to develop policies for the quality improvement. 1) Criteria development : By defining occupational health services, in particular for small and medium sized industries, as one of the primary health care, followings are included as core elements of qualitative occupational health programme; accessibility, continuity, comprehensiveness, technical quality, intersectoral collaboration, emphasis on preventive services, community participation, and adequacy. Again each element is divided into five major components of national health system infrastructure developed by the World Health Organization; development of health resources, organized arrangement of resources, delivery of health care, economic support, and management. In turn, each component is categorized into three aspects of quality assessment, structure, process and outcome. Expert panel selected several criteria for each category to evaluate the programme. Criteria were modified according to each group of interviewees, to produce two sets of questionnaire, one for chief operating officer and another for nurses in the institutions, and the chief operating officer and workers in the workplace. 2) Subject : Of all 52 institutions, 25 voluntarily participated in the survey. At individual institution, chief operating officer and practicing nurses were interviewed in depth. After intensive education for interviewees, every interviewees, every interview was performed with standardized guideline and questionnaire. The quality of the 'Group occupational health service programme' was found to be lower than expected. Especially in continuity, comprehensiveness, technical quality, community participation and adequacy, lower quality in structural aspect was commonly identified throughout all the institutions,. Quality in terms of accessibility and continuity highly varied among institutions., To improve quality of the programme, more comprehensive and systematic programme such as accreditation has to be introduced. In addition, human resources, governmental fund and information systems for individual workers are to be developed. As a long range plan, integration of occupational health services into the national health systems and pooling of financial resources and planned allocation should be considered.
-
백서에서 Depulpin®과 Formocresol에 대한 치수와 치근단 조직의 반응
문형인,김선호,황윤찬,오병주,황인남,김선헌,정선와,윤창,오원만 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.4
One fifth dilution of formocresol is usually for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However, the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it may also alter the pulp tissue rendering it immumologically active, and have carcinogenic potential. Recently Depulpin®(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49% paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier. But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine. Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue, in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present. it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin® group The area of necrotic tissue which had no cells and fibers , was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nucleli. A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resorption and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall. was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.
-
Highly sensitive carbon nanotube-embedding gas sensors operating at atmospheric pressure
Yun, Ju-Hyung,Kim, Joondong,Park, Yun Chang,Song, Jin-Won,Shin, Dong-Hun,Han, Chang-Soo IOP Pub 2009 Nanotechnology Vol.20 No.5
<P>Highly sensitive palladium (Pd) decorated carbon nanotube (CNT) embedding gas sensors working at atmospheric pressure were fabricated. Two types of gas sensors of bare CNTs and Pd nanoparticle decorated CNTs were synthesized by dielectrophoresis. The CNT-containing solution was dropped onto the patterned-platinum electrodes with ac bias. The CNT-embedding sensors sensitively detected 100 ppb level of NO<SUB>2</SUB> in an atmospheric pressure condition. The Pd decoration on CNTs forming the depletion region was found to be an effective way to enhance the sensor response by the control of carrier mobility and density. Raman spectroscopy revealed a low defect ratio of <I>D</I>/<I>G</I><SUP>−</SUP> by heat treatment at 450 °C. Moreover, it was investigated that there exists an optimum temperature to enhance the sensor response. </P>
-
-
-
-
태아에서 발견된 음낭 및 후복강내 낭성 림프관종 1 예
노주영 ( No Ju Yeong ),정재윤 ( Jeong Jae Yun ),민지영 ( Min Ji Yeong ),이혜은 ( Lee Hye Eun ),정병훈 ( Jeong Byeong Hun ),주인숙 ( Ju In Sug ),심재식 ( Sim Jae Sig ),서경용 ( Seo Gyeong Yong ),한석주 ( Han Seog Ju ) 대한산부인과학회 2004 Obstetrics & Gynecology Science Vol.47 No.3
Cystic lymphangioma is a relatively rare congenital malformation of the lymphatic system. It is very rare that retroperitoneal cystic lymphangioma was detected by prenatal ultrasonography. There has been no case reported that scrotal cystic lymphangioma was detected by prenatal ultrasonography. We detected a cystic structure with multiseptation in the scrotum at 30 weeks gestation. In addition, we detected the same structure in the retroperitoneum at 35 weeks gestation by routine ultrasonography. Because of increasing size of the cyst, we performed induction delivery at 38 weeks gestation. Operation of the neonate was performed on the 13th day after birth by a pediatric surgeon and the mass was excised and confirmed as cystic lymphangioma. We experienced a case of huge cystic lymphangioma of the retroperitoneum and scrotum by prenatal sonography and report our case with a brief review of literature.
RISS
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
