컨테이너 운송용 AGV의 운동궤적에 관한 연구

박정보,김민주,이승수,김중완,전언찬 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.5

In this study, we have developed the simulation tool in order to investigate driving trajectory of AGV for container transport. AGV for container transport is different from the indoor AGV in that it is a large size structure at being loaded the weight of 40 ton. And AGV for container transport is applied to front wheel steering, rear wheel steering, all wheel steering, and crap steering. Therefore, we have developed the simulation tool considering dynamic problems and a center of turning in accordance with fourth ways of steering mode. As the result of this study, we have confirmed that this tool is useful and cost-effective in the dynamic analysis or large size vehicles. Also, it is useful to calculate the minimum radius of turning for large size vehicles.

단결정 Si(111) 위에 형성된 Ti-실리사이드에 대한 RBS 및 XRD 분석

이중환,권오준,최치규,박동수,김건호,이상환,이의완,곽호원 濟州大學校 基礎科學硏究所 1991 基礎科學硏究 Vol.4 No.1

초고진공 상태에서 p형 Si(111)기판에 Ti을 증착한 후 고진공에서 열처리하여 Ti-실리사이드를 형성시켰으며, Ti-실리사이드의 상전이 및 형성운동학은 2 MeV⁴He? 이온 후방산란과 x-선 회절방법으로 규명하였다. 형성된 TiSi₂는 결정학적으로 C49(ZrSi₂)와 C54 구조의 두 종류로 확인되었다. C49 TiSi₂상은 열처리온도가 700℃이하의 저온에서 형성되었고, 700℃ 이상의 고온에서는 C54 TiSi₂상으로 나타났다. 본 연구에서 확인된 C54 TiSi₂전이온도(??)는 700℃ 였고, TiSi₂형성온도 영역내에서 TiSi₂ 층두께(χ)와 열처리시간(t)의 관계는 저온(700℃ 이하)일 경우 ??이고, 고온(750℃ 이상)에서는 χ=ct+d 의 관계식이 만족됨을 알 수 있었다. 이것은 700℃ 이하에서 TiSi₂ 형성기구가 Si 확산에 의해 제어되며, 750℃ 이상에서는 핵형성 제어에 의하여 계면반응하는 것으로 나타났다. Titanium silicides were prepared by depositing titanium film on p-type Si(111) followed by annealing in ultra high vacuum. The growth kinetics of Ti-silicide has been studied by using ion backscattering spectrometry and x-ray diffractometry. Two crystallographic structures of Ti-silicide were identified the (ZrSi₂)structure and C54. The C49 TiSi₂ phase was formed at low annealing temperature(<700℃),and it transformed to the C54 phase over 700℃. The relation between the thickness of TiSi₂ layer(χ) and the annealing time(t) was ?? when annealing temperature was under 700℃ and χ=ct+d when that was over 750℃. The former implied that the formation of TiSi₂ was controlled by diffusion and the latter by nucleation of at the Ti/Si(111) interface.

한국산 물푸레나무屬 주요 수종의 해부학적 특성

황원중,권구중,박완근,배영수,김남훈 한국목재공학회 2002 목재공학 Vol.30 No.2

물푸레나무속의 물푸레나무, 들메나무 및 쇠물푸레의 해부학적 특성을 광학현미경법과 화상분석법에 의해 조사하였다. 공시 수종간에 연륜 경계의 명확성을 비롯한 도관 요소의 직경, 축방향유조직의 배열상태, 구성세포의 비율에서 차이가 있었다. 구성요소의 방사방향 변이에 있어서, 목섬유 길이, 도관 요소 직경 및 길이는 수심 부위에서 작고 약 10∼15 연륜까지 증가한 후 안정되었다. 결론적으로 본 연구 결과는 물푸레나무속 세 수종의 식별자료 및 성숙재와 미성숙재를 구분하는 재질 지표치로 이용될 수 있을 것으로 생각된다. Anatomical characteristics of Mulpurenamu (Korean ash, Fraxinus rhynchophylla), Deulmaenamu (Manshurican ash, Fraxinus mandshurica) and Sheamulpure (Sieboldiana ash, Fraxinus sieboldiana) grown in Korea were examined by an optical microscopy and an image analysis. Some characteristics such as boundary of annual rings, shape and size of vessel elements, arrangement of axial parenchyma cells in cross section, and cell volumetric composition showed significant differences between the sample species. In radial variation of elements, fiber length and vessel size increased from the pith for about 10 to 15 years and then reached a more or less constant. The results of this study can be used for identification of wood and indices of wood quality in Fraxinus spp.

국내 의료기관의 항생제 사용 실태와 규제 시스템 조사

방지환,송경호,박완범,김성한,조재현,김홍빈,김남중,오명돈,최강원 대한감염학회 2006 감염과 화학요법 Vol.38 No.6

목적 : 이전 연구들에 따르면 아직까지 국내에서 불필요한 항생제 사용은 무시할 수 없는 수준이며, 특히, 수술환자들에 대한 예방적 항생제 투여가 문제로 지적되고 있다. 많은 병원에서 불필요한 항생제 처방을 제한하려는 노력을 하고 있지만 구체적인 현황에 대한 자료는 적은 실정이다. 이에 본 연구자 등은 국내 의료기관의 항생제 규제 시스템의 현황과 수술시 예방적 항생제 사용의 적정성을 알아보고자 한다. 재료 및 방법 : 전임 감염내과 전문의가 근무하는 의료기관 55곳에 대해 설문조사를 시행하였다. 설문의 내용은 적정한 항생제 사용을 유도하기 위한 정책 및 규제 프로그램, 실제 각 의료기관의 예방적 항생제 사용 현황 등으로 이루어져 있다. 결과 : 55개의 의료기관에 보낸 설문 중 44개가 회수되었다. 회신한 의료기관에서 항생제 처방 관리는 제한항생제 시스템을 가장 많이 이용하고 있었고(95.5%), 항생제에 대한 교육(79.5%), 전산시스템에서 관리(59.1%), 감염내과에 의뢰(54.5%), 항생제 사용 실적 검토(52.3%) 등의 순이었다. 대개의 병원에서 glycopeptides (100.0%), carbapenems (93.0%), quinupristin/dalfopristin 또는 linezolid(93.0%), 4세대 cephalosporin (74.4%), caspofungin 또는 voriconazole (62.8%), liposomal amphotericin B (60.5%) 등을 제한항생제로 분류하여 관리하고 있었다. 모든 의료기관에서 위절제술 및 유방절제술시에 불필요하게 예방적 항생제를 사용하고 있었다. 슬관절치환술의 경우 2세대 cephalosporin을 예방적으로 사용하는 경우가 가장 많았으며(30.2%), 관상동맥우회술의 경우 3세대 cephalosporin을 예방적으로 사용하는 경우가 가장 많았다(47.2%). 예방적 항생제의 투여 기간을 살펴보면 위절제술시 70.5%에서 4일을 초과하여 사용하고 있었고, 유방절제술시에는 63.6%에서, 슬관절치환술시에는 81.8%에서, 관동맥우회술시에는 81.1%에서 4일을 초과하여 장기간 예방적 항생제를 투여하고 있었다. 한편, 예방적 항생제 투여시 aminoglycoside계 항생제를 병용하는 경우도 많았다. 결론 : 아직까지 국내 의료기관에서 항생제 오남용을 막기 위한 노력이 더 필요할 것으로 생각되며, 특히 수술시 예방적 항생제의 올바른 투여에 많은 관심이 필요하다. Background : Previous studies in Korea showed that unnecessary antibiotic use could not be neglected, especially in prophylactic use. Currently many hospitals employ diverse antibiotic stewardship programs, but there are few studies on surveillance of such programs. So, we planned this study to evaluate current status of antimicrobial stewardship and adequacy of antimicrobial prophylaxis in surgery. Materials and Methods : We sent questionnaires about policy on antibiotic usage, control program for adequate antibiotic prescription, and actual status of prophylactic antibiotic usage to 55 infectious disease physicians in each hospital. Results : Of 55 contacted infectious diseases clinicians, 44 answered the questionnaire. Majority of hospitals employed restricted antimicrobial system (95.5%), education (79.5%), control by order communicating system (59.1%), consult to infectious disease physicians (59.1%), and review of cumulative antimicrobial usage (52.3%) to prevent inadequate antibiotic use. Glycopeptides were designated as a restricted antimicrobial agent in 100.0% of hospitals; carbapenems, 93.0%; quinupristin/ dalfopristin or linezolid, 93.0%; the 4th generation cephalosporins, 74.4%; caspofungin or voriconazole, 62.8%; liposomal amphotericin B, 60.5%, and so on. Unnecessary perioperative prophylactic antimicrobial agents were prescribed in gastrectomy and mastectomy in all the hospitals. The second generation cephalosporins and the third generation cephalosporins were the most commonly prescribed prophylactic antimicrobial agents in total knee replacement arthroplasty (TKRA) and coronary artery bypass graft surgery (CABG) respectively. In 70.5% of institutes they use prophylactic antimicrobial agents more than four days in gastrectomy; 63.6% in mastectomy; 81.8% in TKRA; 81.1% in CABG. Unnecessary combination of aminoglycosides with other antimicrobial agents for prophylactic use was another common problem. Conclusion : This study shows that more effort is required to diminish antimicrobial misuse or overuse, especially in prophylactic use for surgical patients.

하계 실내 및 실외환경의 공기 중 휘발성 유기화합물 농도 및 개인노출

양원호,손부순,박종안,장봉기,박완모,김윤신,어수미,윤중섭,류인철 한국환경과학회 2003 한국환경과학회지 Vol.12 No.9

Volatile organic compounds (VOCs) are present in essentially all natural and synthetic materials from petrol to flowers. In this study, indoor and outdoor VOCs concentrations of houses, offices and internet-cafes were measured and compared simultaneously with personal exposures of each 50 participants in Asan and Seoul, respectively. Also, factors that influence personal VOCs exposure were statistically analyzed using questionnaires in relation to house characteristics, time activities, and health effects. All VOCs concentrations were measured by OVM passive samplers (3M) and analyzed with GC/MS. Target pollutants among VOCs were Toluene, o-Xylene, m/p-Xylene, Ethylbenzene, MIBK, n-Octane, Styrene, Trichloroethylene, and 1,2-Dichlorobenzene. Indoor and outdoor VOCs concentrations measured in Seoul were significantly higher than those in Asan except Ethylbenzene. Residential indoor/outdoor (I/O) ratios for all target compounds ranged from 0.94 to 1.51 and I/O ratios of Asan were a little higher than those of Seoul. Relationship between personal VOCs exposure, and indoor and outdoor VOCs concentrations suggested that time-activity pattern could affect the high exposure to air pollutant. Factors that influence indoor VOCs level and personal exposure with regard to house characteristics in houses were building age, inside smoking and house type. In addition insecticide and cosmetics interestingly affected the VOCs personal exposure. Higher exposure to VOCs might be caused to be exciting increase and memory reduction, considering the relationship between measured VOCs concentrations and questionnaire (p<0.05).

STL 포맷의 오류수정을 위한 DB 구축과 형상복구에 의한 효율성 연구

손영지(Young-Ji Son),박정보(Jeong-Bo Park),김순경(Soon-Kyung Kim),김중완(Joong一Wan Kim),전언찬(Eon-Chan Jeon) Korean Society for Precision Engineering 1998 한국정밀공학회지 Vol.15 No.12

골수구성 백혈병 환자에게 발생한 결핵성 림프절염

이창섭,송진수,최평균,조재현,방지환,박경화,박완범,김홍빈,김남중,윤성수,박선양,김병국,오명돈,최강원 대한감염학회 2006 감염과 화학요법 Vol.38 No.5

혈액질환 가운데 결핵 발생이 증가한다고 알려진 것은 호지킨 림프종을 포함한 림프증식성질환 그리고 모양세포성 백혈병 등이 있다. 또한 동종 골수이식을 받은 환자에서도 결핵은 증가한다고 알려져있다. Kaplan 등은 골수구성 백혈병 환자에서 결핵 발생이 증가한다고 보고하였다. 그러나 골수구성 백혈병 환자에서 결핵의 발생이 증가하는 이유에 대해서는 아직까지 정확하게 밝혀지지 않았다. 저자들이 2년 동안 후향적으로 조사한 180명의 성인 골수구성 백혈병 환자들 가운데 결핵이 발생한 환자는 4명이었고, 발생 부위는 모두 림프절이었다. 결핵은 골수구성 백혈병의 특정 아형에만 국한되어 발생하지 않았지만, 50%에서 FAB 분류에 의한 M4였다. 림프절이 종대된 골수구성 백혈병 환자에서 특히, 결핵의 유병율이 높은 나라에서는 결핵성 림프절염도 감별진단에 포함시켜야 한다. During the neutropenic phase, leukemia patients receiving chemotherapy are prone to bacterial and, fungal infections; occasionally mycobacterial, viral and protozoal organisms may also cause infections. Mycobacterium tuberculosis infection was reported very rarely in these patients. This report describes four patients with M. tuberculosis infection identified from 185 adult patients who were diagnosed myelogenous leukemia between January 2003, and December 2004. There was no patient with M. tuberculosis infection from 44 lymphoid leukemia and 11 acute biphenotypic leukemia patients. Sites of infection were all lymph nodes. Three among four patients were presented with lymphadenopathy at initial diagnosis of leukemia, and the other one presented with lymphadenopathy after induction chemotherapy. There was no patient presented with lymphadenopathy during the neutropenic phase. Tuberculous lymphadenitis was presented in a patient with three acute myelogenous leukemia (FAB class 2 M4, 1 M2) and a chronic myelogenous leukemia, accelerated phase. An acute myelogenous leukemia patient had a leukemic cell and tubercle bacilli in the same lymph node. Tuberculosis should also be included as a differential diagnosis in myelogenous leukemia patient with lymphadenopathy, especially in the countries in which the disease is endemic.

Replicative virus shedding in the respiratory tract of patients with Middle East respiratory syndrome coronavirus infection

Park, Wan Beom,Poon, Leo L.M.,Choi, Su-Jin,Choe, Pyoeng Gyun,Song, Kyoung-Ho,Bang, Ji Hwan,Kim, Eu Suk,Kim, Hong Bin,Park, Sang Won,Kim, Nam Joong,Peiris, Malik,Oh, Myoung-don Elsevier 2018 INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES Vol.72 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Information on the duration of replicative Middle East respiratory syndrome coronavirus (MERS-CoV) shedding is important for infection control. The detection of MERS-CoV sub-genomic mRNAs indicates that the virus is replicative. This study examined the duration for detecting MERS-CoV sub-genomic mRNA compared with genomic RNA in diverse respiratory specimens.</P> <P><B>Methods</B></P> <P>Upper and lower respiratory samples were obtained from 17 MERS-CoV-infected patients. MERS-CoV sub-genomic mRNA was detected by reverse transcription PCR (RT-PCR) and MERS-CoV genomic RNA by real-time RT-PCR.</P> <P><B>Results</B></P> <P>In sputum and transtracheal aspirate, sub-genomic mRNA was detected for up to 4 weeks after symptoms developed, which correlated with the detection of genomic RNA. In oropharyngeal and nasopharyngeal swab specimens, the detection of sub-genomic mRNA and genomic RNA did not correlate.</P> <P><B>Conclusions</B></P> <P>These findings suggest that MERS-CoV does not replicate well in the upper respiratory tract.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Middle East respiratory syndrome coronavirus (MERS-CoV) sub-genomic mRNAs indicates that the virus is replicative. </LI> <LI> Sub-genomic mRNA was detected in lower respiratory tract specimens for up to 4 weeks after symptoms developed. </LI> <LI> In upper respiratory tract specimens, the detection of sub-genomic mRNA and genomic RNA did not correlate. </LI> </UL> </P>

The Correlation between Flexi-bar Exercise and Trunk Muscles Strength and Body Composition in Juvenile Soccer Players

Joong San Wang,Si Eun Park,Hee Joon Shin,Wan Suk Choi,Hong Rae Kim,Bo Kyoung Kim,Joo Hyun Park,Joon Hee Lee,Kyung Ok Min 국제물리치료학회 2015 Journal of International Academy of Physical Ther Vol.6 No.1

Juvenile soccer players, Flexi-bar, Trunk muscles strength, Body composition The purpose of this study is to verify a correlation between flexi-bar exercise and improvement of trunk strength and body composition in juvenile soccer players. The subjects were 11 teenager juvenile soccer players who conducted flexi-bar exercise half an hour daily three times a week for eight weeks. They were tested for trunk muscles strength, body composition and correlation. The result showed that trunk muscles strength improved significantly( p<.01) and weight, Rt. arm muscle mass, Rt. leg muscle mass, and Lt. leg muscle mass(p<.05), Lt. arm muscle mass, trunk muscle mass, and body muscle mass(p<.01) improved significantly as well while Lt. arm fat mass, Rt. leg fat mass, and Lt. leg fat mass decreased significantly(p<.05). In the correlation analysis, the more trunk muscle mass and trunk muscles strength increased, the more muscle mass of body regions increased, which was a positive correlation whereas fat mass of body regions decreased, which was a negative correlation. It was verified that there was a correlation between flexi-bar exercise and improvement of trunk muscles strength and body composition for juvenile soccer players.

Changes in Anxiety Level and Personal Protective Equipment Use Among Healthcare Workers Exposed to COVID-19

Park Do Hyeon,Lee Eunyoung,Jung Jongtak,Kang Chang Kyung,Song Kyoung-Ho,Choe Pyoeng Gyun,Park Wan Beom,Bang Ji Hwan,Kim Eu Suk,Kim Hong Bin,Park Sang-Won,Kim Nam Joong,Oh Myoung-don 대한의학회 2022 Journal of Korean medical science Vol.37 No.16

Background: The relationship between changes in anxiety levels and personal protective equipment (PPE) use is yet to be evaluated. The present study assessed this relationship among healthcare workers (HCWs) involved in the care of patients with coronavirus disease 2019 (COVID-19). Methods: An online survey was conducted in a municipal hospital with 195 nationally designated negative pressure isolation units in Korea. Anxiety level was measured using the self-rating anxiety scale (SAS), and changes in anxiety levels were assessed based on the time when COVID-19 vaccine was introduced in March 2021 in Korea. Monthly PPE usage between June 2020 and May 2021 was investigated. Results: The mean SAS score (33.25 ± 5.97) was within normal range and was lower than those reported in previous studies conducted before COVID-19 vaccination became available. Among the 93 HCWs who participated, 64 (68.8%) answered that their fear of contracting COVID-19 decreased after vaccination. The number of coveralls used per patient decreased from 33.6 to 0. However, a demand for more PPE than necessary was observed in situations where HCWs were exposed to body fluids and secretions (n = 38, 40.9%). Excessive demand for PPE was not related to age, working experience, or SAS score. Conclusion: Anxiety in HCWs exposed to COVID-19 was lower than it was during the early period of the pandemic, and the period before vaccination was introduced. The number of coveralls used per patient also decreased although an excessive demand for PPE was observed.