실내 스모그 챔버의 설계 및 성능평가

배귀남,김민철,이승복,송기범,진현철,문길주 한국대기환경학회 2003 한국대기환경학회지 Vol.19 No.4

A multi-functional indoor smog chamber was designed and evaluated lo investigate photochenical or water vapor reaction mechanisms of air pollutants. Various smog chamber experiments could be conducted using ambient air or purified air in this smog chamber. The smog chamber consisted of a housing, a Teflon bag, blacklights, injection ports, sampling ports, and utility facilities. The characteristics of light source, the wall losses of air pollutants, and the quality of purified air were experimentally investigated. The maximum NO₂ photolysis rate was 1.10min^(-1). In a 2.5-m³ Teflon bag, the wall losses of ambient O₃, NO, and NO₂were 1.2~2.4×10^(-3)min^(-1), 0.7~2.0×10^(-3)min^(-1), and 0.4-2.0×10^(-3)min^(-1), respectively. The wall loss of ambient particles ranging 0.05 to 0.2㎛ was 1.8~5.4×10^(-3)min^(-1), which was slightly higher than those of ambient gaseous species. The purified air supply system provided high quality of air with NO₂, < 1 ppb, and total hydrocarbons <5 ppb.

Cutting performance of tungsten carbide tools coated with diamond thin films after etching for various times

Kim, Jong Seok,Park, Yeong Min,Bae, Mun Ki,Kim, Chi Whan,Kim, Dae Weon,Shin, Dong Chul,Kim, Tae Gyu World Scientific Publishing Company 2018 Modern physics letters. B, Condensed matter physic Vol.32 No.20

<P>In this study, diamond thin films were deposited on tungsten carbide tools using surface-wave plasma-enhanced chemical vapor deposition (SWP-CVD). To eliminate the adverse effects of cobalt on the diamond deposition process, the cobalt was removed from the surface of the tools by etching with Murakami’s reagent for various times (30, 60, and 120 min). The cutting performance of the untreated and the diamond-coated WC tools was examined by performing cutting test on carbon fiber-reinforced plastic (CFRP). The results showed that all the diamond-coated tools exhibited great improvement on the durability and wear resistance compared to the uncoated one. In addition, the diamond-coated tool lift time is found to be proportional to the etching time. An increase more than twofold has been achieved when the etch time was increased from 30 min to 120 min.</P>

카올린으로부터 용융 Al의 SiO₂에 대한 선택적 침식을 이용한 Al₂O₃-Al 복합체의 제조

배원태,박민준,박외철 慶尙大學校生産技術硏究所 1994 生産技術硏究所論文集 Vol.10 No.-

½By the use of selective corrosion reaction of molten Al with the SiO₂, Al₂O₃-Al co-continuous ceramic-metal composite was prepared. The optimum conditions to provide maximum value of the mechanical properties such as flexual strength' and fracture toughness has been investigated. The preform was formed at 250㎏/㎝²pressure, fired at 1400℃, and subsequently soaked for 1 hour. The preform corroded with molten Al at 1000℃ for 24 hours had the highest value of mechanical properties. This material showed the bulk density of 3.25g/㎤, 4-point MOR of 280 Mpa, and ?? of 8 MPa. ??. The calculated relative density of the final product consisted of about 50 wt% of aluminum was approximately above 97,5%. If the content of alumina, which provides stiffness, was increased, flexural strength of this material will be greatly imporved. Then the practical applications for brake rotors, piston crowns, cylinder liners, etc. would be expected.

침습성 아스페르길루스증으로 치료받았던 급성 백혈병 환자에서 조혈모세포이식후 발생한 파급성 아스페르길루스증 1례

배기선,박지영,신수연,문영철,최희정,조민선,성주명 대한감염학회 2003 감염과 화학요법 Vol.35 No.4

본 증례는 침습성 아스페르길루스증의 과거력을 갖고 있는 백혈병환자에서 조혈모세포이식을 받은 후 치명적인 파급성 아스페르길루스증이 발병한 예이다. 환자는 항암요법 후 흉부 방사선 및 단층촬영에서 진균성 폐렴을 의심하여 항진균제를 투여하고 폐엽절제술을 시행하여 아스페르길루스에 의한 폐렴임을 확인하였다. Amphotericin B로 치료한 후 조혈모세포이식을 시행받은 뒤 치료에도 불구하고 파급성 아스페르길루스증으로 진행되어 사망하였다. 이 증례에서 보듯이 이전에 아스페르길루스증의 과거력이 있는 경우에 이식후 치명적인 결과를 유발할 수 있으므로, 고위험군을 선별하는 지침과 적절한 치료법에 대한 연구가 필요하겠다. Invasive aspergillosis has been increasing as the number of severe immunocompromised hosts rises. Particularly, in allogeneic hematopoietic stem cell transplantation (HSCT) recipients, incidence of invasive aspergillosis ranges from 4 to 10%. Even with appropriate treatment, the prognosis of invasive aspergillosis in allogeneic HSCT recipients remains poor, showing high mortality rate. Herein. we report a case where invasive aspergillosis in a patient with acute myelogeneous leukemia progressed to disseminated aspergillosis after allogeneic HSCT. A 31-year-old woman with acute myelogenous leukemia had invasive aspergillosis after third reinduction chemotherapy. After administering amphotericin B, the patient underwent the wedge resection of lung. and HLA-matched allogeneic HSCT was then conducted. On day 14 of transplantation, the patient died of disseminated aspergillosis, including possible cerebritis and endocarditis despite the amphotericin B therapy.

퍼지제어를 이용한 이족보행 로봇의 보행

배지훈,강민구,김종철,김갑일 明知大學校 産業技術硏究所 2000 産業技術硏究所論文集 Vol.19 No.-

In this paper, a biped robot is designed and implemented, and walking tests are performed using a stable walking model. In order to embody the human joint structure, designed biped robot has two degree of freedom attached to the pelvic area of each leg. Using two motors for each ankle makes it possible to have the same degree of freedom as human ankle. This paper show that fuzzy control algorithm is suitable for each joint control.

초음파 센서를 이용한 이동 로봇

배지훈,김종철,박경용,강민구,김갑일 明知大學校 産業技術硏究所 2000 産業技術硏究所論文集 Vol.19 No.-

In this paper, design and construction of mobile robot is conducted and the error reduction and obstacle avoidance techniques is introduced. Up to now, in the design of most mobile robots, there are emphasis on the compensation of tracking errors using the additional sensors and guidance method, rather than the reduction of the tracking errors of motor itself and wheel errors. In this purpose, high performance motor and encoder are used for the driving actuator, and the acceleration/deceleration technic is introduced to reduce the driving errors. Also ultrasonic sensor performs obstacle avoidance, which is proved using the driving test.

치수유래 구심성 신경섬유의 삼차신경 감각핵군에서의 연접특성

배용철,이은희,최민기,홍수형,김현정,남순현,김영진 대한소아치과학회 2001 大韓小兒齒科學會誌 Vol.28 No.2

일차연접부위에서 악안면 영역에서 유래하는 유해자극의 전달 및 처리기전을 이해하고자 horseradish pe개xidase를 치수지배 구심성 신경섬유를 표식한 후 연수후각에서 미세구조 및 연절 양상을 분석하여 다음과 같은 결과를 얻었다. 표식종말은 소수의 큰 치밀소포가 관찰되는 종말 (S형) 및 다수의 치밀소포를 함유하는 종말 (LDCV형)등 2종류로 분류할 수 있었다. S형 및 LDCV형 표식종말의 연접양식은 유사하였으며, 다수의 표식종말이 1개 혹은 2개의 neurofile과 연접을 이루어 대단히 단순한 연접양상을 보였다. 표식종말은 가지돌기체 보다는 다수의 가지돌기가시와 연접을 이루는 빈도가 높았다. 표식종말이 세포체 및 이에 인접한 근심부 가지돌기와 연접하는 경우는 드물었으며, 소수의 표식종말에서 p-ending과 연접하는 경우를 보였다. 표식종말의 체적, 표면적, 사립체의 체적, neurofile과 접하는 면적, 활성부위의 면적, 단위표식종말당 연접소포의 수 및 연접소포의 밀도등은 넓은 범위의 계측치를 나타내었으며, 이는 5명 및 LDCV형 표식종말 사이에 유의한 차이가 없었다. 이상의 결과로 미루어보아 연수후각에서 치수유래 구심성 신경섬유 종말의 연접양식은 고유의 특징을 보이며 이는 신경회로의 기능과 밀접한 상관관계를 가지는 것으로 판단되었다. Little is known about processing mechanism of pain sensation of the oral cavity at the 1st synapse of trigeminal sensory nuclei. Serial ultrathin sections of tooth pulp afferent terminals, identified by the transganglionic transport of 1% wheatgerm agglutinin conjugated horseradish peroxidase, were investigated wih electron microscope. Quantitative ultrastructural analysis was performed on digitizing tablet connected to Macintoshi personal computer (software: NIH Image 1.60, NIH, Bethesda, MD). Labeled boutons could be classified into two types by the shapes of containing vesicles : S bouton which contained mainly spherical vesicles (Dia. 45-55 nm) and few large dense cored vesicles (Dia. 80-120nm), and LDCV bouton, which contained spherical vesicles as well as large number of large dense coredd vesicles. Most of the parameters on the ultrastruotural characteristic and synaptic organization of labeled boutons were similar between S and LDCV boutons, except shapes of containing vesicles. Majority of the labeled boutons showed simple synaptic arrangement. The labeled bouton were frequency presynaptic to dendritic spine, and to a lesser extent, dendritic shaft. They rarely synapsed with soma and adjacent proximal dendrite. A small proportion of labeled boutons made synaptic contacts with presynaptic pleomorphic vesicless containing endings and synaptic triad. Morphometric parameters of labeled boutons including volume and surface area, total apposed area, mitochondrial volume, active zone area, vesicle number and density showed wide variation and theme were not significantly different between S and LDCV boutons. The present study revealed characteristic features on ultrastructure and synaptic connection of pulpal afferents which may involved in transmission of oral pain sensation.

물체의 표면 반사특성을 고려한 이치화 및 물체 복원

배철민,문영식 漢陽大學校 工學技術硏究所 1996 工學技術論文集 Vol.5 No.1

In many vision tasks one of the major obstacles is the specular highlight of smooth objects, which causes a misinterpretation of objects. The paper presents an efficient algorithm for highlight detection and object reconstruction, based on the theory of photometric stereo in which the location of highlight changes as the position of illumination source changes. Two images, referred to as base image and reference image, are sequentially taken with two different positions of the illumination source but from the same viewing direction. The reference image is normalized by the average of the two images. The difference image is thresholded to detect the specular spike of the highlight. Then the specular lobe around the specular spike is detected to reconstruct the object. The proposed algorithm can be applied to metals and dielectrics, regardless of the surface characteristics. This method can also be applied to the case when the background is brighter than the object.

12주간의 태권도 트레이닝이 남자 청소년의 골밀도 및 골 건강관련 호르몬에 미치는 영향

김민형 ( Min Hyung Kim ),정현철 ( Hyun Chul Jung ),강효정 ( Hyo Jung Kang ),김현배 ( Hyun Bae Kim ),송종국 ( Jong Kook Song ) 한국스포츠정책과학원(구 한국스포츠개발원) 2012 체육과학연구 Vol.23 No.4

The purpose of the study was to evaluate the effects of weeks taekwondo training on bone mineral density, and calcemic hormones in male adolescents. 19 male adolescents aged 13-14 years (12 for training group; 7 for control group) were participated in this study. Taekwondo group has been performed 50 minutes a days a week for 12 weeks, as exercise intensity of 60-70 % HRR (heart rate reserver). Control group have only performed the activities included in their physical education classes. Skeletal maturity was assessed by TW3. Bone mineral density at the sites of lumber spine, forearm, femur and whole body were assessed by DXA (Hologic. QDR-4500, USA). Blood samples were drown in the morning after 12-h fast and spun at 3000 rpm for 15 min. 25(OH)D and calcitonin were analyzed by Liaison (Diasorin, USA). Osteocalcin was analyzed by COBAR 5010 (Quantum Packard. USA). Parathyroid hormone was analyzed by E170 (Roche, Germany) and growth hormone was analyzed by Immulite 2000 (DPC, USA). Statical analyses were done with SAS version 9.2. All data were presented in terms of means and standard deviations. Two-wany ANOVA with repeated measure was used for interaction of time x group. Paired t-test was perfomed to change over time in each parameter. Multiple regression analysis was used to find factors that influence dependent variables. A statistically significant level was defined as 95%. The results of this study indicates that bone age for TG (14.9±0.62yr) was significantly advanced compared to chronological age (14.0±0.64yr). but CG had similar bone age (14.1±0.55yr) compared to chronological age (13.9±0.46yr). significant within subjects effects were found for whole body BMD(p<.001), lumbar BMD (p<.001) and forearm BMD (p<.0001). Significant increase could be obtained in TG for whole body BMD, lumbar BMD, and forearm BMD between pre and post-tests However, there was no difference for femoral BMD for both TG and CG. Although no difference was found for serum osteocalcin in CG, significant increase could be observed in TG between pre and post-tests. There was significant within subject effect for PTH in TG (p<.05). Significant interaction effect of group and time was found for GH (p<.0001). serum 25 (OH)D was significantly decreased in both groups throughout the study periods. Bone age, serum calcitonin and lean tissue were predictors for whole body BDM in explaining 51.0%, 64% and 74.0% respective in TG. Bone age was significant predictor for lumbar BMD in explaining 39.0% in TG. In conclusion, 12 weeks taekwondo training has positive effects on bone mineral density and calcemic hormones in male adolescents. Further study is needed to enhance femral BMD as taekwondo training over 12 weeks and higher intensity. 이 연구의 목적은 12주간의 태권도 트레이닝이 남자 청소년의 골밀도와 골 건강관련 호르몬에 미치는 영향을 규명하는 것이었다. 연구대상자는 13~14세 남자 청소년 19명이었으며, 이들을 훈련군(12명)과 통제군(7명)으로 분류하였다. 골격성숙도는 TW3 방법을 적용하여 RUS 점수와 뼈나이를 평가하였고, 골밀도는 DXA를 이용하여 측정하였다. 골 건강관련 호르몬은 osteocalcin(OC), calcitonin(CC), parathyroid hormone(PTH), growth hormone(GH)과 25-hydroxyvitamin D(25(OH)D)를 분석하였다. 그룹 간 태권도 트레이닝 전·후 종속변인의 차이를 규명하기 위해 반복 이원분산분석을 적용하였고, 그룹 내 차이는 대응 t-검정을 이용하여 분석하였다. 골밀도와 뼈나이, 체중, 신장, 골 건강관련 호르몬의 관계를 규명하기 위해 다중회귀분석을 적용하였다. 이 연구 결과 훈련군의 전신 골밀도(p<.001), 요추 골밀도(p<.001), 전완 골밀도(p<.01)는 12주 태권도 트레이닝 전·후 통계적으로 유의하게 증가하였으나 통제군은 유의한 변화가 없었다. 한편 대퇴 골밀도는 훈련군과 통제군 모두 12주 트레이닝 전·후 유의한 변화가 나타나지 않았다. OC는 훈련군(pre: 13.18ng/mL, post: 40.38ng/mL)과 통제군(pre: 13.04ng/mL, post: 40.89ng/mL) 모두 통계적으로 유의하게 증가한 반면, CC는 두 그룹 모두 유의한 변화가 없었다. PTH는 훈련군의 경우 통계적으로 유의하게 감소하였지만(p<.05), 통제군은 유의한 차이를 보이지 않았다. GH는 트레이닝 전·후 훈련군과 통제군에서 유의한 상호작용효과가 나타났으며(p<.05), 훈련군(pre: 0.70ng/mL, post: 4.22ng/mL)에서는 증가한 반면 통제군(pre: 5.40ng/mL, post: 2.04ng/mL)에서는 감소하였다. 25(OH)D는 훈련군과 통제군 모두 통계적으로 유의하게 감소하였다. 골밀도의 예측변인을 분석한 결과 훈련군에서 전신 골밀도의 경우 뼈나이, 제지방조직, 신장이 높은 설명력을 보였고, 요추 골밀도의 경우 뼈나이, 전완 골밀도의 뼈나이, PTH, 생활나이가 유의한 설명력을 나타냈다. 결론적으로 12주간의 태권도 트레이닝은 남자 청소년들의 골밀도와 골 건강관련 호르몬에 긍정적인 영향을 미친 것으로 나타났으며 태권도 트레이닝이 청소년들의 요추 골밀도에 영향을 미치기 위해서는 12주 이상의 장기간의 훈련을 통한 후속연구가 필요할 것으로 사료된다.

산전 초음파로 진단된 선천성 수신증 태아의 경험 1례

강민아,김도균,최석철,양회생,배철성,윤혜원,심재철,하달봉 동국대학교 경주대학 1997 東國論集 Vol.16 No.1

Prenatal ultarsound represents an accurate and reliable method for the detection of intrauterine anomalies, especially urinary tract anomalies. Hydronephrosis is the most common congenital condition detected by prenatal ultrasound. Prenatal ultrasonographic diagnosis allows a good condition and therapeutic assessment of the patients prior to serious impairment of renal function so that in most cases the urological surgeon can opt for a parenchymal conserving procedure. The authors have experienced a case of congenital ureteropelvic obstruction with hydronephrosis diagnosed at 32 weeks of pregnancy and report our experience with a brief review of literature.