• 한국안전학회지
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• 제16권4호
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• pp.103-108
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• 2001

Explosive limit is one of the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limits are used to classify flammable liquids according to their relative flammability. Such a classification is important for the safe handling of flammable liquids which constitute the solvent mixtures. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this paper, Raoult,s law and van Laar equation(activity coefficient model) are shown to be applicable for the prediction of the explosive limits in the flammable ethylacetate-toluene system. The values calculated by the proposed equations were a good agreement with literature data within a given percent. From a given results, by the use of the proposed equations, it is possible to predict explosive limits of the other flammable mixtures. It is hoped eventually that this method will permit the estimation of the explosive Properties of flammable mixtures with improved accuracy and the broader application for other flammable stances.

• 한국환경보건학회지
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• 제50권1호
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• pp.16-24
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• 2024

Background: Indoor PM_2.5 concentrations in residential houses can be affected by various factors depending on the season. This is because not only do the climate characteristics depend on the season, but the activity patterns of occupants are also different. Objectives: The purpose of this study is to compare factors affecting indoor PM_2.5 concentrations in apartments and detached houses in Daegu according to seasonal changes. Methods: This study included 20 households in Daegu, South Korea. The study was conducted during the summer (from July 10 to August 10, 2023) and the autumn (from September 11 to October 9, 2023). A sensor-based instrument for PM_2.5 levels was installed in the living room of each residence, and measurements were taken continuously for 24 hours at intervals of one minute during the measurement period. Based on the air quality monitoring system data in Daegu, outdoor PM_2.5 concentrations were estimated using ordinary kriging (OK) in Python. In addition, the indoor activities of the occupants were investigated using a time-activity pattern diary. The affecting factors of indoor PM_2.5 concentration were analyzed using multiple regression analysis. Results: Indoor and outdoor PM_2.5 concentrations of the residences during summer were 15.27±11.09 ㎍/m³ and 11.52±7.56 ㎍/m³, respectively. Indoor and outdoor PM_2.5 concentrations during autumn were 13.82±9.61 ㎍/m³ and 9.57±5.50 ㎍/m³, respectively. The PM_2.5 concentrations were higher in summer compared to autumn both indoors and outdoors. The primary factor affecting indoor PM_2.5 concentration in summer was occupant activity. On the other hand, during the autumn season, the primary affecting factor was outdoor PM_2.5 concentration. Conclusions: Indoor PM_2.5 concentration in residential houses is affected by occupant activity such as the inflow of outdoor PM_2.5 concentration, cooking, and cleaning, as found in previous studies. However, it was revealed that there were differences depending on the season.

• Advances in Traditional Medicine
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• 제8권2호
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• pp.103-110
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• 2008

Herbal medicine is the use of medicinal plants for prevention and treatment of diseases: it ranges from traditional and popular medicines of every country to the use of standardized and tritated herbal extracts. Generally cultural rootedness enduring and widespread use in a traditional medical system may indicate safety, but also efficacy of treatments, especially in herbal medicine where tradition is almost completely based on remedies containing active principles at very low and ultra low concentrations or relying on magical-energetic principles. The efficacy and safety assessments of medicines, whether modern or herbal, invariably encounter challenges or problems during the course of pre-clinical and clinical research. Some of the challenges in evidence-based herbal medicinal research are unique, and the researcher must be cognizant of them in order to safeguard the quality of the data obtained. Key challenges are: the quality of raw materials; appropriateness of biological/pharmacological activity assessment methodology, and data interpretation; standardization methodology; pharmacokinetics and bioavailability of active constituents and metabolites; clinical dosage formulation/production; and clinical study designs and outcome measures.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 춘계학술대회
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• pp.1-11
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• 2012

Risk Assessment, a basis of health and safety management system, is an calamity prevention activity which regularly measure the level of a risk to passively improve potential hazard. A problem, the assessment not being improved to be applied to the construction work site where requires diversity and complexity, causes the assessment to be inefficient to bring quality results. A study on the investigates and compares the surveyed degree of recognitions of workers who works in companies executing the risk assessment By the investigation and comparison, it is expected to bring the better solution for early and efficient application for those companies which are not taking the risk assessment.

• 한국식품위생안전성학회지
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• 제14권4호
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• pp.422-427
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• 1999

천연 항균활성 물질에 관한 대부분의 연구는 약품의 제조와 첨가물로서의 이용을 목적으로 하였으나, 물질의 효용면에서 연구결과를 실용화시키기에는 미흡한 실정이다. 이러한 사실은 천연물질의 항균성을 실제 식품에 이용하는 덴 필요한 가공적성의 연구가 따르지 못한 것이 주요한 이유라고 여겨진다. 본 연구는 우리나라 사람들이 즐겨먹는 부추의 항균활성을 연구하되, 식품에 이용할 수 있도록 항균물질의 특성규명과 더불어 가공적성을 평가하여 실제 적용하는데 목적을 두었다. 생부추즙을 agar diffusion method로 항균활성을 측정한 결과는 Bacillus cereus, Bacillus subtilis, Stayhlococcus aureus, Pseudomonas fluorescens. E. coli O157:H7 등의 세균류와 효모인 Pichia membranaefaciens등에 항균작용을 나타내었다. 생부추 착즙과 생부추 동결 후 착즙한 시료에서만 항균활성을 나타내었고 착즙한 후의 동결저장 시료나 데친 시료에서는 항균활성이 소실되었다 한편 여과와 원심분리 및 진공농축 그리고 pH변화 등에 의해서는 항균활성의 변화가 없었다. 항균활성 기초자료에 근거하여 가공식품의 모델로서 부추 마쇄시료를 첨가한 두유와 두부 및 냉면육수를 제조하여 식품응용 시험을 한 결과 부추를 첨가한 각각의 제품에서 미생물 성장 저해효과가 나타났으며, 특히 냉면육수의 경우 인위적으로 Bacillus cereus를 접종시켰음에도 불구하고 1$0^{\circ}C$, 20시간 저장시 부추를 첨가한 육수에서 미생물이 완전히 사멸되는 효과를 얻을 수 있었다.

• Molecules and Cells
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• 제42권3호
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• pp.262-269
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• 2019

The porcine myeloid antimicrobial peptide (PMAP), one of the cathelicidin family members, contains small cationic peptides with amphipathic properties. We used a putative lysozyme originated from the bacteriophage P22 (P22 lysozyme) as a fusion partner, which was connected to the N-terminus of the PMAP36 peptide, to markedly increase the expression levels of recombinant PMAP36. The PMAP36-P22 lysozyme fusion protein with high solubility was produced in Escherichia coli. The final purified yield was approximately 1.8 mg/L. The purified PMAP36-P22 lysozyme fusion protein exhibited antimicrobial activity against both Gram-negative and Grampositive bacteria (Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, and Bacillus subtilis). Furthermore, we estimated its hemolytic activity against pig erythrocytes as 6% at the high concentration ($128{\mu}M$) of the PMAP36-P22 lysozyme fusion protein. Compared with the PMAP36 peptide (12%), our fusion protein exhibited half of the hemolytic activity. Overall, our recombinant PMAP36-P22 lysozyme fusion protein sustained the antimicrobial activity with the lower hemolytic activity associated with the synthetic PMAP36 peptide. This study suggests that the PMAP36-P22 lysozyme fusion system could be a crucial addition to the plethora of novel antimicrobials.

• 항공우주정책ㆍ법학회지
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• 제25권2호
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• pp.113-137
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• 2010

국제 사회에서는 그 동안 항공안전의 향상을 위하여 많은 노력과 활동을 전개하여 왔다. 새로운 첨단기술과 시스템, 그리고 전 세계 어디서나 보다 정밀한 항행을 할 수 있도록 도와주는 항법장비의 발전은 항공안전의 수준을 상당히 향상시켜 왔다. 그러나 전 세계의 항공 사고율은 1980년대 이후부터 별다른 감소 추세 없이 계속해서 정체현상을 보이고 있다. 이는 기존의 항공안전 향상을 위한 노력만으로는 이제 더 이상 항공기의 안전 운항을 보장해 줄 충분한 수준의 안전 확보가 어렵다는 것을 의미하며, 결국 사고예방을 위한 새로운 방법이 필요하게 되었다. 이러한 점을 주목하여 전 세계 항공국들은 항공기 사고로 인명 또는 재산상의 손실이 발생하기 전에 전 항공시스템 내에서 초기 위험요소들을 사전에 인지하여 그에 대한 적절한 개선 대책을 개발할 수 있는 새로운 방식에 관심을 가지게 되었는데 그것은 항공안전정보시스템의 구축을 통한 안전정보의 수집 분석 공유를 하는 것이다. 세계적인 항공안전정보시스템을 구축하기 위해서는 각 나라의 정보들을 수집하고 분석할 수 있는 항공사고 준사고 보고시스템 구축을 기본으로 이용자간에 자유스럽게 교환이 이루어져야 한다. 또한 시스템을 구성하는 항공안전 데이터들의 분류체계가 표준화되어 이용자간의 정보가 원활히 소통될 수 있어야 하겠다. 이 연구에서는 항공안전 정보를 효과적으로 분석하고 필요한 예방활동을 결정할 수 있는 각 나라의 항공사고 준사고 데이터베이스 분류체계를 조사를 통하여 세계 항공안전 강화에 기여함은 물론 국가 항공 외교력 증진에도 도움이 되고자 한다.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.37-44
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• 2023

Using the Kalman filtering technique, we propose a novel method for estimating the missing video frames to monitor the activities inside the control room of a nuclear power plant (NPP). The purpose of this study is to reinforce the existing security and safety procedures in the control room of an NPP. The NPP control room serves as the nervous system of the plant, with instrumentation and control systems used to monitor and control critical plant parameters. Because the safety and security of the NPP control room are critical, it must be monitored closely by security cameras in order to assess and reduce the onset of any incidents and accidents that could adversely impact the safety of the NPP. However, for a variety of technical and administrative reasons, continuous monitoring may be interrupted. Because of the interruption, one or more frames of the video may be distorted or missing, making it difficult to identify the activity during this time period. This could endanger overall safety. The demonstrated Kalman filter model estimates the value of the missing frame pixel-by-pixel using information from the frame that occurred in the video sequence before it and the frame that will occur in the video sequence after it. The results of the experiment provide evidence of the effectiveness of the algorithm.

• 대한치과의사협회지
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• 제53권2호
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• pp.96-102
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• 2015

There is a need to comprehend dental accidents accurately, and construct patient-safety-system in order to prevent consistently increasing dental accident or dispute. This study is aimed to provide basic data for an efficient counterplain by looking through and classifying already occurred dental accidents from an angle of patient safety. Recently, the number of dispute on dental implant was the highest according to rapid growth of dental implant. As a result of classifying dental accidents by International Classification for Patient Safety (ICPS), it is confirmed that cause of accident is different by each type of dental treatment. It is expected to help preventing and managing dental disputes properly by studying actual state of dental disputes in perspective of patient safety. Effort to reduce dental accidents and activity to pursue patient safety have thread in connection. I believe that financial profits of dental clinic and improvement of quality in dental treatment can be achieved through these efforts.

• Safety and Health at Work
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• 제3권3호
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• pp.166-180
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• 2012

This review summarizes the epidemiology of cancer of the female reproductive system and associated lifestyle factors. It also assesses the available evidence for occupational factors associated with these cancers. Cervical, endometrial, and ovarian cancers are relatively common, and cause significant cancer morbidity and mortality worldwide, whereas vulvar, vaginal, fallopian tube cancers, and choriocarcinomas are very rare. As several lifestyle factors are known to play a major role in the etiology of these cancers, very few published studies have investigated possible relationships with occupational factors. Some occupational exposures have been associated with increased risks of these cancers, but apart from the available evidence on the relationships between asbestos fibers and ovarian cancer, and tetrachloroethylene and cervical cancer, the data is rather scarce. Given the multifactorial nature of cancers of the female reproductive system, it is of the utmost importance to conduct occupational studies that will gather detailed data on potential individual confounding factors, in particular reproductive history and other factors that influence the body's hormonal environment, together with information on socio-economic status and lifestyle factors, including physical activity from multiple sources. Studies on the mechanisms of carcinogenesis in the female reproductive organs are also needed in order to elucidate the possible role of chemical exposures in the development of these cancers.