병원획득 Klebsiella pneumoniae 균혈증 분석을 통해 본 Ciprofloxacin 내성과 Extended-Spectrum β-Lactamase생성 간의 연관성

김미영,추은주,곽이경,송문희,나성수,송태준,김성혜,전재범,최상호,정진용,김남중,김양수,우준희,류지소 대한감염학회 2004 감염과 화학요법 Vol.36 No.5

목적 : K. pneumoniae는 ciprofloxacin내성 증가가 전세계적으로 문제가 되고있는 extended-spectrum beta-lactamase (ESBL)를 생성하는 대표적인 세균으로 최근 외국에서 ciprofloxacin 내성과 ESBL 생성사이에 관련이 있다는 2-3편의 보고들이 있었다. 본 연구에서는 병원획득 K. pneumoniae 패혈증이 있었던 환자들을 대상으로 ciprofloxacin 내성과 관련된 인자를 알아보고자 하였다. 재료 및 방법 : 2001년 1월 부터 2002년 12월 사이에 2200병상의 3차 의료기관인 한 대학병원에서 입원 후 72시간 이후에 나간 혈액배양에서 K. pneumoniae가 배양된 입원환자를 대상으로 의무기록과 전산기록을 분석하여 환자의 성별, 나이, 병동, 기저질환, 이전의 항생제 사용력, 패혈증 발생당시까지의 재원기간, 이전 입원력, 원인균의ESBL 생성유무 등을 파악하였고 이들 변수가 ciprofloxacin 내성과 관련이 있는지를 분석하였다. 재발성 패혈증의 경우는 첫 번째 경우만을 분석에 포함하였다. 결과 : 연구대상 환자는 총154명이었고 K. pneumoniae의 ciprofloxacin에 대한 내성률은 28.6% (44/154)였다. Ciprofloxacin 내성균주 중 ESBL 생성균주의 비율은 95.5% (42/44)였고 ciprofloxacin 감수성균주에서 ESBL 생성균주의 비율은 24.5% (27/110)였다(P<0.001). ESBL생성외에 단변량 분석에서 유의한 관련을 보인 변수로는 남자, 나이가 많은 경우, 패혈증 당시 중환자실 재원, 기저질환이 고형암, 혈액암, 담도계 질환인 경우, 패혈증 발생이전 1달 이내의 항생제 사용력, 3세대 cephalosporin, metronidazole, fluroquinolone, carbapenem 투여력이 있었다. 다변량 로지스틱 분석을 시행 하였을 때는 나이가 많은 경우(Adjusted odds ratio[A0R]; 1.04, 95%confidence interval[CI]; 1.01-1.06)와 ESBL 생성(AOR; 81.35, 95% CI; 17.76-372.53)이 유의하게 ciprofloxacin 내성과 관련이 있었다. 결론 : 패혈증을 일으킨 병원획득 K. pneumonias에서의 ciprofloxacin 내성은 ESBL 생성과 유의한 관련을 보였고 향후 이에 관련된 원인이나 기전을 분석하기위한 분자역학적·분자생물학적 연구가 필요하겠다. Background : Strains of ciprofloxacin-resistant Klebsiella pneumoniae have emerged worldwide. We investigated the epidemiology of ciprofloxacin resistance and its relationship to ESBL production in nosocomial K. pneumoniae bacteremia. Materials and Methods : Using the computerized database of clinical microbiology, we identified all patients whose blood culture had yielded K. pneumoniae between January 2001 and December 2002 at a 2200-bed university-affiliated tertiary-care hospital. During the study period, total of 392 episodes of K. pneumoniae bacteremia were documented of which 163 episodes were acquired nosocomially. 9 cases of recurrent episodes were excluded. Results : The resistance rates to ciprofloxacin was 28.6% (44/154). ESBL-production was significantly more common in ciprofloxacin-resistant isolates than in ciprofloxacin-susceptible isolates (95.9% [42/44] vs. 24.5% [27/110], P<0.001). In univariate analysis, following factors were significantly associated with resistance to ciprofloxacin: older age, male sex, ICU admission at the time of bacteremia, prior use of antibiotics within 1 month before bacteremia, solid tumor, hematological malignancy, or biliary disease as underlying disease, and ESBL-production. The prior use of 3^(rd)-generation cephalosprins, metronidazole, fluroquinolone, or carbapenem were also risk factors. Independent risk factors for ciprofloxacin resistance were older age (adjusted odds ratio [AOR]; 1.04, 95% confidence interval [CI]; 1.01-1.06) and ESBL production (AOR; 81.35, 95% CI; 17.76-372.53). Conclusion : The close relationship between ciprofloxacin resistance and ESBL production was documented in nosocomial K. pneumoniae bacteremia. Further epidemiological and molecular studies to determine factors and mechanisms involved in the relationship are needed.

당뇨병 환자에서 혈장 Thrombin-Antithrombin Ⅲ 및 Plasmin-α_2-Plasmin Inhibitor 복합체의 임상적 의의

김경욱,김은숙,정상수,윤수지,박우일,이준희,남수연,안철우,문병수,김경래,차봉수,송영득,임승길,이현철,허갑범 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.25 No.5

연구배경:당뇨병 환자에서 혈액응고 및 섬유소용해 체계의 이상경향이 있어 그 결과로 여러 혈관합병증의 발생위험이 높다는 사실은 널리 알려져 있다. 그 기전은 아직 확실히 밝혀지지 않았으나, 고혈당으로 인한 혈장 단백질들의 비효소성 당화작용이나 산화성 스트레스로 인한 유리 라티칼 작용으로 응고항진이나 섬유소용해 활성의 저하를 유발하는 것으로 생각되고 있다. 최근 응고 및 용해인자와 그 억제자의 복합체들의 증가가 이 상태를 비교적 예민하게 반영한다고 알려져 있다. 방법:본 연구에서는 당뇨병 환자 101명과 정상 대조군 20명에서 혈장내 thrombin­antithrombin complex(TAT)와 plasmin­α₂­plasmin inhibitor complex(PIC)를 측정하여 비교하고, 당뇨병 환자에서 미세혈관 합병증과 대혈관합병증의 유무에 따른 차이와, 이미 혈관 질환의 위험인자로 알려져 있는 인자들간의 상관성을 알아보고자 하였다. 결과:1. 환자의 분포를 살펴보면 혈관합병증이 있는 군은 85명, 혈관합병증이 없는 군은 16명이었고, 평균연령은 각각 57.9±14.1세, 49.9±16.6세로 혈관 합병증이 있는 군에서 더 나이가 많았고, 체질량지수는 23.2±3.4㎏/㎡, 24.1±3.4㎏/㎡로 두 군간 유의한 차이는 없었다. 또 두 군간의 혈압 및 HbA1c, 공복혈당 및 인슐린과 C­peptide, 총 콜레스테롤, 중성지방, HDL­콜레스테롤, Lp⒜는 유의한 차이가 없었고, 미세혈관합병증이 있는 군에서 당뇨병의 유병기간이 길었다. 2. TAT 및 PIC의 농도는 정상 대조군에서는 2.8±1.2 ng/mL, 240.4±69.7 ng/mL이었고, 당뇨병 환자군에서는 9.5±22.6 ng/mL, 472.2±258.7 ng/mL이었다. TAT와 PIC 모두 당뇨병 환자군에서 정상 대조군에 비해 유의하게 증가되어 있었고(p<0.001), TAT/PIC ratio는 두 군간 차이가 없었다. 3. 당뇨병 환자의 혈관합병증에 따른 TAT 및 PIC, fibrinogen 농도는 합병증이 없는 군은 각각 4.1±2.4ng/mL, 362.2±272.0ng/mL, 322.7±102.4mg/mL으로 PIC와 fibrinogen의 증가를 보였으나, 연령을 보정한 후에는 통계학적 유의성은 없었다. 또 대혈관 합병증군에서는 각각 6.0±4.9 ng/mL, 507.4±321.6 ng/mL, 427.1±194.7 mg/dL이었으며 미세·대혈관 합병증군에서는 10.4±6.4 ng/mL, 484.8±269.7 ng/mL, 388.4±132.4 mg/dL으로 TAT의 증가를 보였으나 역시 연령을 보정한 후에는 통계학적 유의성은 없었다. 4. 미세혈관합병증군에서 HbA1c(>8%)가 높은 군의 PIC 농도가 유의하게 높았고(p=0.049), 대혈관합병증군에서 HbA1c(>8%)가 높은 군의 총 콜레스테롤 농도가 유의하게 높았다(p=0.042). 5. 총 당뇨병 환자군에서 PIC는 fibrinogen과 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며(r=0.47, 0.31,-0.25), 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다(r=0.67). 결론:이상의 결과에서 혈장 TAT 및 PIC 농도는 당뇨병 환자에서 정상 대조군에 비해 의미있게 증가되어 있었고, 당뇨병 환자군에서는 연령의 증가와 유병기간이 혈액응고항진 및 용해의 장애에 큰 역할을 함을 알 수 있었으며, 총 당뇨병 환자군에 PIC와 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다. 따라서 당뇨병 환자에서 혈액응고 및 용해의 장애가 동반되어 있다고 볼 수 있으며, 혈장 TAT 및 PIC는 혈관합병증으로의 진행을 예측하는 지표로서 유용하리라 생각된다. 또 혈당조절정도와 상관성이 있으므로 혈당조절후에 추적검사를 시행하여 합병증의 예방이 가능한지 추후 연구가 필요하리라 생각된다. Background : Abnormality of coagulation and fibrinolystic system is known as a predisposing factor of vascular complication in diabetes. Although the pathogenesis is not well known, non-enzymatic glycation reaction and the increase in production of free radicals due to an increased oxidative stress may be linked to the hypercoagulibility and hypofibrinolytic activity. As indices of abnormality in coagulation and firinolysis in peripheral blood, plasma thrombin-antithrombin Ⅲ complex (TAT) and plasmin-α_2-plasmin inhibitor complex (PIC) were measured. The purpose of this study was to clarify whether hypercoagulability exists in diabetic patients with or without vascular complication. Methods : In our study, we measured plasma thrombin-antithrombin Ⅲ compelx (TAT) and plasmin-α_2-plasmin inhibit or complex (PIC) in 101 diabetic subjects and 20 controls. Comparing TAT and PIC levels in diabetic microvascular complication group, diabetic macrovascular complication group and controls, we examined correlation between risk factors associated with diabetic vascular complication. Results : 1. The group with diabetic vascular complication was older than group without complication. There was no significant difference in BMI, blood pressure, HbA_ic, blood sugar level, insulin, C-peptide, serum creatinine, total cholesterol, triglyceride, HDL-cholesterol, Lp (a) between two groups. The group with diabetic microvascular complication had longer duration of diabetes. 2. Concentration of TAT and PIC were 2.8±1.2 ng/ mL, 240.4±69.7 ng/ mL in controls and 9.5±22.6 ng/ mL, 472.2±258.7 ng/ mL in diabetic patients, respectively. TAT and PIC were significantly higher in diabetic patients than in control (p<0.001). But TAT/PIC ratio was no significant difference between two groups. 3. In diabetic patients, concentration of TAT and PIC and fibrinogen were respectively 4.1±2.4 ng/ mL, 362.2±272.0 ng/ mL, 322.7±102.4 mg/ dL in group without vascular complication and 5.3±4.1 ng/ mL, 529.5±258.7 ng/ mL, 374.9±106.2 mg/ dL in group with microvascular complication, which group had increase in PIC and Fibrinogen but no significance after correction of age. Concentration of TAT and PIC and Fibrinogen were 60.±4.9 ng/ mL, 507.4±321.6 ng/ mL, 427.1±194.7 mg/ dL in macrovascular complication, and 10.4±6.7 mg/ mL, 484.8±269.7 ng/ mL, 388.4±132.4 mg/ dL in combined vascular complication which group showed increase of TAT but also had no significant increase after correction of age. 4. In diabetic microvascular complication patients, group of high HbA_1c (>8%) (p=0.049) had significant high PIC concentration. In diabetic macrovascular complication patients, group of high HbA_1c (>8%) (p=0.042) had significant high total cholesterol concentration. 5. In all diabetic patients, PIC was positively correlated with fibrinogen and HbA_1c and negatively correlated BMI (r=0.47, 0.31, -0.25). Only in daibetic patients without angiopathy, TAT was positively correlated with HbA_1c (r=0.67). Conclusion : In this study, plasma TAT and PIC concentration significantly increased in diabetic patients compared with controls, and PIC was increased in group with microvascular complication, TAT were increased in group with combined micro macrovascular complication. However, there was no significance relationship existed when correctinf for age. PIC was correlated with HbA_1c. TAT was correlated with HbA_1c only in the group without angiopathy. Abnormality of coagulation and fibrinolysis were combined in diabetes, plasma TAT and PIC can be used as an index of vascular complication. Also we found the correlation with the degree of the blood glucose control. Therefore we need follow up study for the possibility of prevention of vascular complication after controlling the blood glucose to age-matched patients (J Kor Diaabetes Asso 25:354~363, 2001).

151종 생약제 추출물이 B형 간염 바이러스 표면 항원(HBsAg)과 항체(HBsAb)의 결합반응 그리고 HBV DNA polymerase 활성에 미치는 효과 : 한국산 각종 생약제를 이용한 B형 간염치료제의 개발

정태호,김정철,김문규,이인선,채성철,김승래,정준모,이인수,김승호,함경수 慶北大學校 醫科大學 1992 慶北醫大誌 Vol.33 No.3

세계인구 43억명 중 B형 간염 바이러스 보균자는 2억 1천 5백만명이며 이중 78%인 1억 6천만명 이상이 아시아 대륙에 집중되어 있다. 한국도 B형 바이러스 간염의 침윤지대이다. 본 연구는 B형 바이러스 보균자 혹은 만성간염을 치료할 수 있는 생약제를 탐색할 목적의 일환으로 한국에서 시판하는 생약제 151종을 구입하여 증류수로 추출하고 여과한 후 냉동건조하여 HBs 항원에 대한 결합능, HBV DNA polymerase억제능, tumor necrosis factor(TNF) 유리에 미치는 영향, 그리고 galactosamine 유발 간염에 대한간장보호 작용을 조사하였다. 151종의 생약제중 0.16㎍/㎖ 농도에서 간염 vaccine 내에 함유된 HBs 항원과 결합하는 생약제는 지유, 가자, 복분자, 대황, 정향, 빈량, 산수유, 소목, 마황, 쇄양, 후박, 목과, 양강, 오약, 산사, 목단피 등 16종이었다. 이들 생약제중 대황(Rheum palmatum L. 大黃), 가자(Terminalia chebula R. 訶子), 지유(Sanguisorba officinalis L. 地楡), 복분자(Rubus coreanus M. 覆盆子)는 HBV DNA polymerase 활성도를 비교적 강하게 억제하였으며 빈량(Areca catechu L. 빈랑), 정향(Eugenia caryophyllata T. 丁香), 목과(Chaenomeles japonica L. 木瓜), 산수유(Cornus officinalis S. 山茱萸)는 약하게나마 HBV DNA polymerase 활성을 억제하였다. 또한 HBV DNA polymerase를 억제한 대황, 가자, 지유, 복분자, 빈량, 정향, 마황, 소목, 산수유를 대상으로 TNF 유리에 미치는 영향을 조사한 결과 소목을 제외한 8종의 생약제 모두가 대식세포를 자극하여 TNF를 유리시켰다. 그리고 장차 임상에 사용함을 전제로 HBV DNA polymerase를 억제한 대황, 가자, 지유, 복분자, 빈량, 정향, 마황, 소목, 산수유를 galactosamine 유발 간염(백서)에 투여하여 간기능 검사에 미치는 효과를 조사하였으나 간기능 검사상으로는 특별한 보호작용을 나타내지 못하였으며 생약제 단독 투여로서는 간기능에 대하여 나쁜 영향을 주지 않았다. Hepatitis B virus infection is major cause of acute and chrome hepatitis, cirrhosis of liver, and hepatocellular carcinoma. There are over 200 million carriers of hepatitis B virus in the world, nearly 80 % of whom live in the South East Asia, Korea is also highly endemic area of hepatitis B virus infection. This study was performed to evaluate the effect of extracts of traditional Korean herbal medicines on hepatitis B virus. 151 traditional herbs were extracted, filtered and lyophilized. Using 151 herbal extracts we tested binding capability to the HBs Ag, inhibition of HBV DNA polymerase, release of tumor necrosis factor (TNF), and protection against galactosamine induced liver damage. Among 151 herbs, 16 herbs (Sanguisorba officinalis L., Terminalia chebula R., rubus coreanus M., Rheum palmatum L., Eugenia caryophyllata T., Areca catechu L., Cornus officinalis S., Caesalpinia sappan L, Ephedra sinica S., Cynomorium songaricum R., Machilus thunbergii S., Chaenomeles japonica L., Alpinia officinarum H., Lindera strychnifolia V., Crataegus pinnatifida B., Paeonia suffruticasa A. ) had binding capability to HBs Ag which contained in the commercial hepatitis vaccine, at 16 ug/㎖ of concentratioa Among the above 16 herbs, Rheum palmatum L., Terminalia chebula R., Sanguisorba officinalis L., Rubus coreanus M. significantly inhibited the HBV DNA polymerase activity, and Areca catechu L., Eugenia caryophyllata T., Ephedra sinica S., Caesalpinia sappan L., Chaenomeles Japonica L., Cornus officinalis S. also inibited the HBV DNA polymerase activity but less effective. All of the herbs, except Caesalpinia sappan L., which inhibited the HBV DNA polymerase activity, actively stimulated the mononuclear cells to release tumor necrosis factor(TNF) in whole blood culture system. The herbs which inhibited the HBV DNA polymerase activity, did not show any protective effect in galactosamine-induced hepatitis in rats, but there was no direct toxic effect when herbs were administered alone.

달 탐사선의 발사 요구조건 및 임무궤도 사례연구

석병석(Suk, Byong-suk),민승용(Min, Seung-yong),권재욱(Kwon, Jae-wook),김창균(Kim, Chang-kyoon),문상만(Moon, Sang-man),최수진(Choi, Su-jin),구철회(Koo, Cheol-hea),김인규(Kim, In-kyu),류동영(Ryu, Dong-young) 한국항공우주연구원 2015 항공우주산업기술동향 Vol.13 No.2

시험용 달 궤도선의 발사 요구조건 사전 분석 단계로 최근 외국에서 발사한 달 탐사선의 발사 요구조건을 분석하였다. 일반적으로 달 탐사선의 발사 요구조건은 달 임무 궤도를 결정하는 중요한 요소이며, 또한 지구, 달, 태양의 상대적인 운동으로 인해 임무궤도 요구조건을 만족하는 발사 가능 시간이 주기적으로 반복되는 경향이 있다. 분석 결과 설정된 발사 요구조건들로부터 달 궤도선의 주 임무가 달의 남/북극 지역의 광학 관측 임을 간접적으로 알 수 있었다. 향후 우리나라 달 궤도선 발사 요구 조건 설정에 본 논문이 도움이 되길 기대한다. In the preliminary study on launch window requirement for Korea Path-finder Lunar Orbiter(KPLO), the recent foreign lunar orbiter’s lauch window requirement was analyzed. Normally, the launch requirements depends on the mission orbit. Based on the relationship between Moon, Earth, and Sun, the launch time will be available periodically to meet requirements. In this paper, it is understood that the launch window requirements come from payload mission requirements to take picture each poles of Moon. This paper might be a practical example to derive KPLO launch requirements in the future.

병원급식 위탁관리의 운영 실태조사

김진수,양일선,김현아,박문경,박수연 대한영양사협회 2003 대한영양사협회 학술지 Vol.9 No.2

The purposes of this study were to investigate the current status of contracted hospital food services and to find out the difference in accordance with the number of beds in hospitals. Thirty six hospitals having more than 100 beds in Seoul, Inchon and Kyungkido were the subjects of this study. Data was collected through surveys. The survey was conducted during March and April in 2002. The Questionnaires were mailed to the 36 directors of dietetic departments of the hospitals and 36 managers of contracting patient food services. Statistical analysis was completed using SPSS Win(11.0) for descriptive analysis and t-test. The results of the study are summerized as follows; Ⅰ. Hospital perspective : The range covered by contract food service was 63.3% and 36.7% in hospital food services, and medical nutrition services. The patient and employee food services were in 83.3% and patient food services were in 6.7%. The methods selecting contractors were general, limited, selected and competitive biddings, and private contracts. The responsibility for supervision of contract food services was the dietetic department(51.7%) in most cases. Hospitals having personnel responsible for contracting affairs were in 75.9% of the cases and 24.1% did not have personnel. The biggest reason for contracting was facilitation of personnel management. The most important criteria on selecting food services contractors was the professionality of the contractor. Ⅱ. Contractor's perspective : The cost per meal in the year 2001 was composed of 1,905 won for food cost, 1,081 won for labor cost, 222 won for expenses, 114 won for VAT, 14 won for rent and 146 won for miscellaneous or controllable expense, representing 109 won loss per meal. The profit-and-loss contract cost was higher than the fee-contract cost. The ratios of food cost, labor cost and expenses were higher and the ratios of miscellaneous or controllable expense, VAT, rent and profit were lower in hospitals with more than 400 beds compared with those less than 400 beds. However, no significant differences are present between these two groups of hospitals. The actual contract period was 2.2 years upon initial contract and 1.2 years upon renewal. The initial investment cost was 53 million won and the cost of renovation and repair was 8.5 million won. Significant differences were present between two groups of hospitals. The conditions of employment and number of personnel hired by contractors for contract patient food services were significantly different according to the number of beds.

수분산성 과불소아크릴/폴리우레탄 복합체의 합성

김정두,유수용,문명준,이민규 한국공업화학회 2005 응용화학 Vol.9 No.1

Waterborne fluoroacylic/polyurethane composite dispersions were prepared by emulsion polymerization. Polyurethane containing hydrophilic groups previously prepared by step growth polymerization and this was dispersed with fluoroalylic monomer and other monomers in water. The structure of the composite were confirmed by using ATR-FTIR. The surface and film properties of the composites were investigated by the measurement of contact angle, surface free energy, DSC, and TGA and these properties were compared with those of physical polymer blends. As the amounts of Perfluoralkyl ethyl acrylate(FA) emulsion was increased from 0 wt% to 20 wt%, the surface energy was dramatically decreased from 37.54 dyne/cm to 14.22 dyne/cm. But little change of the contact angle observed in the amount of the FA emulsion up to 20 wt%. The results showed the advantages of the composite dispersions over the physical polymer blends.

水稻의 播種樣式과 播種量이 移秧機用 苗素質에 미치는 影響

金文圭,金聲來,安壽奉 충남대학교 농업과학연구소 1978 農業技術硏究報告 Vol.5 No.2

In order to get healthy seedling of rice suitable for rice transplanter, the growing characteristics of the seedling grown under different growing days and sowing densities were invesigated and the results obtained were summarized as follows; In the 20 days old seedling, the difference of growing state of seedling and its characteristics between the two types of nursery bed was not found, but for the 30 days old seedling, both of the crop growth rate and the relative growth rate on the band-type nursery bed appeared higher than those on the mat-type nursery bed. And also, the dry weight, the content of cardohydrate and the ratio of dry weight to plant height of the seedling grown on the band-type nursery bed were much higher than those on the mat-type nursery bed, however the amount of difference of seedling characteristics between two types of nursery bed was decreased for 40 days old seedling and leaf number was not increased. The amount of the seedling growth was increased with less density of sowing and for the difference between the higher and the less density, the difference getting bigger with the longer nursery days. The maximum density of sowing was approximately 200cc per nursery case on the band-type nursery bed and 250cc per nursery case on the mat-type nursery bed. It was seemed that the growing uniformity of the seedling grown on the mat-type nursery bed was better than that on the band-type nursery bed, As the coefficient of variation of the plant height and leaf numbers of the seedling grown on the band-type nursery bed was higher than that on the mat-type nursery bed.

기계시각을 이용한 강구 자동 검사장치

김윤수,박수우,임병훈,김태균,최병재,박철영,이문락,도용태 대구대학교 정보통신연구소 2008 情報通信硏究 Vol.5 No.1

Metal balls are commonly used in mechanical elements and systems including bearings. If there is a defect in a metal ball, it can cause a serious machine failure. By this reason every balls produced are required to be inspected, and the inspection is usually done by human eyes. However, the inspection by human eyes is always with the risk of mistakes, and a need to automate the inspection process is arisen. This paper describes a design of an automatic inspection system for detecting defects on ball surface. A machine vision system is used, and design process and techniques are described in detail. 강구는 베어링을 비롯한 기계 요소 및 장치에서 널리 사용되는 부품이다. 만약 강구에 결함이 있을 시, 이를 사용하는 기계에서 치명적인 결함이 초래될 수 있다. 따라서 제조된 강구에 대해서는 전량검사가 요구되고 있고, 검사과정은 사람의 육안에 의한 검사가 주를 이루고 있다. 그런데 사람에 의한 검사에는 항상 실수의 가능성이 있으므로, 이를 자동화하는 것이 필요하다. 본 논문에서는 강구의 표면 결함을 자동적으로 검사할 수 있는 장치를 설계한다. 기계시각 장치가 사용되었고, 설계에 따른 구체적 절차와 기술들이 서술된다.

Benzoyl peroxide의 환경에서의 초기 위해성 평가

김미경,배희경,김수현,송상환,구현주,박광식,이문순,전성환,나진균 한국환경독성학회 2004 환경독성보건학회지 Vol.19 No.1

Benzoyl peroxide is a High Production Volume Chemical, which is produced about 1,375 tons/year in Korea as of 2001 survey. The substance is mainly used as initiators in polymerization, catalysts in hte plastics industry, bleaching agents for flour nad medication for acne vulgaris. In this study, quantitative Structure-Activity Relationships(QSAR) are used for getting adequate information on the physical-chemical properties of this chemical. And hydrolysis in water, acute toxicity to aquatic and terrestrial organisms for benzoyl peroxide were studied. The physical-chemical properties of benzoyl peroxide were estimated as followed; vapor pressure=0.00929 pa, Log K_(ow)=3.43, Henry's Law constant=3.54×10^(-6) atm-m³/mole at 25℃, the half-life of photodegradation=3days and bioconcentration factor(BCF)=92. Hydrolysis half-life of benzoyl peroxide in water was 5.2hr at pH 7 at 25℃ and according to the structure of this substance hydrolysis product was expected to benzoic acid. Benzoyl peroxide has toxic effects on the aquatic organisms. 72 hr-ErC_(50)(growth rate) for algae was 0.44mg/L, 48hr-EC_(50) for daphnia was 0.07mg/L and the 96hr-LC_(50) of acute toxicity to fish was 0.24mg/L. Acute toxicity to terrestrial organisms(earth worm) of benzoyl peroxide was low(14 day-LC_(50)=>1,000mg/kg). Although benzoyl peroxide is high toxic to aquatic organisms, the substance is not bioaccumulated because of the rapid removal by hydrolysis (half life=5.2hr at pH 7 at 25℃) and biodegradation(8.% by BOD after 21days). The toxicity observed is assumed to be due to benzoyl peroxide rather than benzoic acid, which shows much lower toxicity to aquatic organisms. One can assume that effects occur before hydrolysis takes place. From the acute toxicity value of algae, daphnia and fish, an assessment factor of 100 was used to determine the predicted no effect concentration(PNEC). The PNEC was calculated to be 0.7㎍/L based on the 48hr-EC_(50) daphnia(0.07mg/L). The substance shows high acute toxicity to aquatic organisms and some information indicates wide-dispersive use of this substance. So this substance is a candidate for further work, even if it hydrolysis rapidly and has a low bioaccumulation potential. This could lead to local concern for the aquatic environment and therefore environmental exposure assessment is recommended.

아동의 문제행동 발견과 프로그램 개발

문선화,김영호,이경남,장수한 부산대학교 사회복지연구소 2000 社會福祉硏究 Vol.10 No.-