• 한국식품위생안전성학회지
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• 제12권3호
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• pp.240-253
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• 1997

The main problems contributing to food poisoning outbreaks in institutional settings and a home were reviewed and analyzed through the epidemiological investigations of food poisoning. The major documented factors included improper holding temperatures, inadequate cooking, poor personal hygiene, cross-contamination and contaminated equipment, food from unsafe sources, failure to follow food hygiene policies, and lack of education, training, monitoring and superivision. Usually more than one factor contributed to the development of an outbreak. (1) Use of improper holding temperatures was the single most important factor contributing to food poisoning. They included improper cooling, allowing a laps of time (12 hours or more) between preparing food and eating it, improper hot holding, and inadequate or improper thawing. Food thermometers were not used in most of the instances. (2) In inadequate cooking, the core temperature of food during and after cooking had not been measured, and routine monitoring was limited to recording the temperature of plated meals. Compared with conventional methods of cooking, microwave ovens did not protect against food poisoning as effectively. Centralized food preparation potentially increased the risk of food poisoning outbreaks. (3) Poor personal hygiene both at the individual level (improper handwashing and lack of proper hygienic practices) and at the institutional level (poor general sanitization) increased the risk of transmission. Person to person transmission of enteric pathogens through direct contact and via fomites has been noted in several instances. (4) Obtaining food from unsafe sources was a risk factor in outbreaks of food poisoning. Food risks were high when food was grown or harvested from contaminated areas. Possibilities included contamination in the field, in transport, at the retail site, or at the time it was prepared for serving. (5) Cross-contamination and inadequate cleaning/handling of equipment became potential vehicles of food poisoning. Failure to separate cooked food from raw food was also a risk factor. (6) Failure to follow food hygiene policies also provided opportunities for outbreaks of food poisoning. It included improper hygienic practices during food preparation, neglect of personnel policies (involvement of symptomatic workers in food preparation), poor results on routine inspections, and disregarding the results and recommendations of an inspection. (7) Lack of formal and in-service education, training, monitoring, and supervision of food handlers or supervisors were critical and perhaps neglected elements in occurrences of food poisoning.

• 대한치과보철학회지
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• 제37권4호
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• pp.506-515
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• 1999

Dental practice can produce and spread some infectious diseases from patients to dentist, dental assistant, and dental labors. One possible method for preventing these cross-contamination is to immerse dental impression in chemical disinfectants. So for many investigators studied on the dimensional changes of dental impressions and on the surface qualities of stone casts made from impression following immersion in disinfectants. This study was proposed to evaluate some popular impression disinfectant combination from the point of dimensional stability. Impression was taken from dental arch-shaped metal model. Irreversible hydrocolloid and 3 elastomers(polyvinyl siloxane, polysulfide, polyether) were immersed in 3 disinfectants (2% glutaraldehyde, 1% povidone-iodine, 0.5% sodium hypochlorite) for 10 minutes and measured both cross-arch and anterior-posterior distance under stereo microscope to evaluate dimensional change. The results obtained were as follows: 1. Dimensional changes of irreversible hydrocolloid impression was statistically different in cross-arch and anterior-posterior distance when immersed in 2% glutaraldehyde solution and in anterior-posterior distance when immersed in 0.5% sodium hypochlorite solution from control group (p<0.05). 2. Dimensional changes of polyvinyl siloxane and polysulfide impression were not statistically different from control group (p>0.05). 3. Dimensional changes of polyether impression was statistically different in cross-arch distance when immersed in 0.5% sodium hypochlorite solution and in anterior-posterior distance when immersed in 1% povidone-iodine solution from control group (p<0.05). 4. In all cases, dimensional changes were less than 0.1% from the original dimension and concluded clinically acceptable.

• 상하수도학회지
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• 제26권3호
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• pp.361-372
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• 2012

In order to establish the methodology for estimating an emergency drinking water supply in Korea, overseas cases and accidents history of cutting off water supply were investigated, and questionnaire was conducted. Investigating accidents history of cutting off water supply in Korea, actual cutting off times of most cases were less than 13hours. Also, cases related with water quality and facility failure have been not enough to derive useful information for estimating an emergency water. From the results of questionnaire and cross-tabulation analysis, about 1,066 lpcd(liter per capita${\cdot}$day) as an emergency water and 14 days as tolerable outages time could be estimated. The results of water quality simulation could tell us that it might take 5-16 days for pollutant matter to travel from 15 contamination points to source water intake point in the selected reservoir(D-dam). This travel time was in good accordance with the estimated tolerable outage time, 14days.

• 전기화학회지
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• 제16권3호
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• pp.99-110
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• 2013

레독스 플로우 전지(RFB)는 대형에너지 장치로서 신재생 에너지와 같은 전력발생이 일정하지 못한 상황이나 전력수요가 급증감하여 효율적인 에너지의 운용이 요구될 때 효과적으로 사용할 수 있는 전지모델이다. 일부 상용화된 종류도 있지만 다양한 레독스 쌍과 소재가 연구됨에 따라 개선의 여지가 많은 전지이다. 본 총설에서는 전지의 레독스 쌍(redox pair)의 종류들에 대한 설명을 통하여 레독스 플로우 전지의 전반적인 이해를 돕고자 한다. 레독스 쌍의 혼합오염, crossover, 이온 선택성, 용해도 등의 개선을 통해서 새로운 레독스 플로우 전지의 탄생을 기대할 수 있다. 용량의 개선을 위해서 다양한 수계 및 비수계 레독스 쌍의 연구가 되고 있는데 crossover에 의해 다소의 용량손실이 있다고 하더라도 혼합오염이 없는 전지라면 레독스 플로우 전지의 내구성의 장점을 살릴 수 있을 것이라 기대한다. 혼합오염이 없는 레독스 플로우 전지 중에는 멤브레인이 필요 없는 전지도 새로운 연구방향으로 모색되고 있다.

• 한국식품위생안전성학회지
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• 제27권4호
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• pp.427-431
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• 2012

본 연구는 고춧가루 제조 가공업체를 대상으로 고춧가루의 원료 및 공정별, 제조시설 및 작업자 손, 제조환경에 대한 일반세균, 진균, 대장균군 및 병원성 미생물에 대한 미생물학적 위해도를 조사하였다. 제조공정별 시료에서는 분쇄 공정 후에 높은 오염도가 나타났으며 자외선 살균후에도 미생물 감소에 큰 효과가 나타나지는 않았다. 제조시설 및 작업자 손의 오염은 즉각적인 조치를 강구해야 할 정도의 오염도를 보여 제조시설 소독과 개인위생교육을 실시함으로써 교차오염에 주의할 필요가 있다. 제조환경 조사 결과, 모든 구역에서 오염도가 나타났으며, 특히 청결구역으로 지정되어 있는 내포장실에서 비교적 높은 수준의 오염도가 나타났다. 이에 따라 공기 순환을 통해 공중낙하균을 억제하는 등 청결한 위생관리를 위한 방법이 수립되어야 할 것으로 사료된다.

• 대한소아치과학회지
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• 제35권4호
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• pp.628-634
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• 2008

최근 치과계에는 교차감염의 문제가 점차 대두되고 있으며, 그 감염경로에는 혈액이나 구강 분비물을 통한 직접접촉과 진료실 장비 등에 의한 간접접촉이 있다. 또한 병원 등 한정된 공간 내에 많은 인원이 수용된 환경에서는 공기 중을 떠다니는 오염물질에 의한 공기 감염에 보다 많은 관심이 모아지고 있으며, 치과 진료실에서는 고속회전 핸드피스에서 발생하는 분무에 의한 감염이 가장 우려되고 있는 상황이다.따라서 본 실험에서는 치과 진료실 내 핸드피스 분무에 의한 공기 중 세균 감염 위험성을 파악하고 실제 진료 시, 감염 방지에 도움을 주는데 그 목적을 두었으며, 다음과 같은 결론을 얻었다. 1. 핸드피스를 사용해 진료한 군 97.4 cfu, 핸드피스를 사용하지 않고 진료한 군 5.6 cfu로 핸드피스를 사용해서 진료한 군에서 박테리아 군집의 수가 높게 나타났으며 통계학적으로 유의한 차이를 보였다(P<0.01). 2. 핸드피스 사용 시 러버댐을 같이 사용한 진료는 22.4 cfu로 러버댐을 사용하지 않고 진료하는 경우보다 박테리아 군집의 수가 낮게 나타났으며,통계학적으로 유의한 차이를 보였다(P<0.01).3. 핸드피스 물 공급원으로 관주용액을 사용한 경우와 증류수를 사용한 경우를 비교 시 관주용액을 사용한 경우 cfu는 22.4 cfu, 증류수의 경우 17.0 cfu로 측정되었으나, 통계학적으로 유의한 차이를 보이지 않았다. (P>0.05). 4. 핸드피스를 사용해 진료하는 경우, 0.5m와 1.5m 거리에서 측정 시 97.4cfu와 22.0 cfu로 0.5m 거리에서 박테리아 군집의 수가 높게 나타났으며 통계학적으로 유의한 차이를 보였다(P<0.01). 또한 원거리에서도 핸드피스 분무에 의해 박테리아가 검출되었다. 5. 박테리아균을 분류한 결과 그램양성 구균의 수가 73.9%로 가장 많은 비중을 보였고, 그램음성 구균, 그램음성 간균, 그램양성 간균의 순이었다.

• Food Science and Biotechnology
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• 제16권3호
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• pp.361-366
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• 2007

As the application of quantitative risk assessment (QRA) to food safety becomes widespread, it is now being questioned whether experimental results and simulated results coincide. Therefore, this paper comparatively analyzed experimental data and simulated data of the cross contamination, which needs summation of the simplest calculations in QRA, of chicken by Monte Carlo simulation and fuzzy math computation. In order to verify summation, the following basic operation was performed. For the experiment, thigh, breast, and a mixture of both parts were preserved for 24 hr at $20^{\circ}C$, and then the cell number of Salmonella spp. was measured. In order to examine the differences between experimental results and simulated results, we applied the descriptive statistics. The result was that mean value by fuzzy math computation was more similar to the experimental than that by Monte Carlo simulation, whereas other statistical descriptors by Monte Carlo simulation were more similar.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제1권1호
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• pp.53-60
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• 1995

Several kinds of medical materials are supplied and returned or disposed everyday in hospitals. And so, the transportation system has to be planned according to their circulation. This study aimed at clarifying the relation between the stock area in ward and the departments in which the contaminated materials are disposed or recleaned and the utilization of vertical transportation system with regard to contaminated materials. The results are as follows : 1)The stock area/rooms for contaminated materials are dipersed according to their kinds. Several department have relation with the area/rooms in ward. 2)The vertical transportation system for contaminated materials are not reserved and utilized independently in hospitals surveyed. And so, cross contamination can easily occur. Therefore, independent transportation system is required and utilized only for them.

• Earthquakes and Structures
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• 제15권3호
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• pp.263-273
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• 2018

Operational modal analysis is being widely used in aerospace, mechanical and civil engineering. Common research fields include optimal design and rehabilitation under dynamic loads, structural health monitoring, modification and control of dynamic response and analytical model updating. In many practical cases, influence of noise contamination in the recorded data makes it difficult to identify the modal parameters accurately. In this paper, an improved frequency domain method called Enhanced Least Square Complex Frequency (eLSCF) is developed to extract modal parameters from noisy recorded data. The proposed method makes the use of pre-defined approximate mode shape vectors to refine the cross-power spectral density matrix and extract fundamental frequency for the mode of interest. The efficiency of the proposed method is illustrated using an example five story shear frame loaded by random excitation and different noise signals.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.367-370
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• 2005

The risk from genetically modified (GM) plants results from the possibility of gene contamination producing adverse effects on biological diversity by introducing herbicide or insect resistance into related plants or weeds (NAS 2002). The concern about the leakage of genes from GM plants into the environment has primarily focused on pollen that could be wind-borne for long distances. During the period of fisk assessment in Japan, physical containment is applied as a measure of reducing gene flow via the dispersal of pollen from GM plants into the surrounding environment In this study, we tried to estimate the effect of physically contained greenhouse covered by 1-mm fine mesh to reduce pollen dispersal by researching cross pollination rate between non-GM yellow maize in a greenhouse and silver maize outside the greenhouse.