• 대한전기학회논문지:전력기술부문A
• /
• 제48권9호
• /
• pp.1055-1063
• /
• 1999

This paper present a conceptual possibilistic approach using fuzzy set theory to manage the uncertainties in the given reliability input date of the practical power system. In this paper, an algorithm is introduced to calculate the possibilstic reliability indices according to the degree of uncertainty in the given data. The probability distribution function can be transformed into an appropriate possibilstic representation using the probability-Possibility Consistency principle(PPCP) algorithm. In this the algorithm, the transformation is performation by making a compromise between the transformation consistency and the human updating experience. Fuzzy classifcation theory is applied to reduced the number of load data. The fuzzy classification method determines the closeness of load data points by assigning them to various clusters and then determening the distance between the clusters. The IEEE-RTS with 32-generating units is used to demonstrate the capability of the proposed algorithm.

• 대한환경공학회지
• /
• 제31권9호
• /
• pp.783-792
• /
• 2009

서울 인근의 하수처리장에서 채취한 유입/유출수에 내포되어 있는 31개의 미량 EDC/PPCPs(내분비계장애물질/의 약 개인관리용품물질)의 발현 특성에 대한 조사 연구를 수행하였다. 유입수에서 검출된 EDC/PPCPs의 용도별 분류에 따른 총농도 관점의 발현 비율은 각성제(59.67%), X선 조영제(20.20%), 난연제(9.00%), 기타 등의 순으로 나타났으며, 유출수의 경우에는 베타 차단제(30.54%), 난연제(20.49%), X선 조영제(18.17%), 기타 등의 순으로 발현 빈도가 나타났다. 본 연구에서 검출된 대상 미량물질의 전반적인 농도 검출 범위는 다른 국내 선행연구에 비해 다소 낮은 것으로 나타났으며, 국외의 연구결과와 비교해서는 상당한 낮은 수준으로 검출되는 것으로 나타났다. 특히 유럽 지역의 연구결과와 비 교하면 일부 의약물질항목에 따라서는 수천 배의 농도차이를 보여주는 것으로 나타났다. 한편, 선택된 9개의 의약물질에 대해 유입수와 유출수의 예상환경농도(PEC)를 계산하고 실제 측정된 농도(MEC)와 비교한 결과 물질별 발현 농도 수치 관점에서는 큰 편차를 보였으나, 물질별 상대적 발현 빈도 순서 관점에서는 대체적으로 유사한 것으로 나타났다.

• 한국환경보건학회지
• /
• 제42권1호
• /
• pp.53-60
• /
• 2016

Objectives: Preservatives are commonly used in pharmaceuticals, cosmetics and other products to extend the expiration date and prevent the growth of microorganisms. Preservatives are generally effective in controlling mold and inhibiting yeast growth, and against a wide range of bacterial attacks as well. They also adversely affect the quality of sperm and cause precocious puberty in children. This study was performed to analyze seven preservatives used in pharmaceuticals and personal care products. Methods: Five kinds of pharmaceuticals and personal care products (PPCPs) were examined for analysis with a high performance liquid chromatography-diode array detector. Each sample was homogenized and the targeted compounds were extracted with methanol. The suspended particulate was removed by syringe filter. Next, the sample was injected into an HPLC system. The separation of the seven preservatives was achieved with a C18 column and gradient mode. The accuracies were between 73% and 120% and precision was lower than 11.58% (RSD). Results: All of the calibration curves showed good linearity with a coefficient of determination ($r^2$) over 0.999. Among the PPCP samples, the detection rate of preservatives was 32.5% for pharmaceuticals, 44.8% for toothpaste, 76.9% for mouthwash, 40.0% for body lotion and 56.0% for wet tissues. The average concentrations of the preservatives in PPCPs were BA 1141.0 mg/kg, MP 709.8 mg/kg, EP 624.9 mg/kg, PP 216.9 mg/kg, BP 167.8 mg/kg, and TCS 538.2 mg/kg. The most frequently detected preservatives in pharmaceuticals and personal care products were BA, MP and PP. The concentrations of preservatives exceeded Korean regulatory standards in 11 samples of medicines, three of mouthwash and two of body lotion. Conclusion: We found that most of the PPCP samples contained various preservatives. It is necessary to identify which preservatives were used and to determine the level of preservatives in PPCPs and to assess the health risk to susceptible populations such as children.

• 한국물환경학회지
• /
• 제35권6호
• /
• pp.574-579
• /
• 2019

As interest in health issues increases, it is imperative to ensure good water quality from wastewater treatment plant effluent to preserve environmental health. In particular, currently there is a lack of water ecosystem risk assessment on pharmaceutical substances remaining in effluent. In this study, antidepressant escitalopram (ESC), antiepileptic carbamazepine (CBZ) and lead, which impact the behavior of aquatic organisms, were used to test their impact on the potential behavior of zebrafish. Zebrafish have been widely used in toxicological assessment studies due to the ease of handlinggenerically and genetically. It was possible to observe changes in the growth of organisms through monitoring the embryos' cognitive and behavior assessment. In this study, the embryo lethal dose test showed that the lethal concentration of ESC and CBZ was at 10 ppb, which is below the water quality criterion (100 ppb), increased by 32.5 % and 40 %, respectively. In the cognitive test, it was found that the cognitive ability function decreased by 22 % and 17% for ESC(500 ppb) and CBZ(1,000 ppb) respectively relative to control. Based on these results, it is necessary to initiate efforts to remove these trace pollutants from sewage treatment facilities to protect the health of aquatic organisms.

• 대한환경공학회지
• /
• 제22권2호
• /
• pp.211-216
• /
• 2000

본 연구는 오염가스 제거시 발생되는 부산물인 에어로졸 입자가 방전전극에 부착되어 생기는 방전불안으로 제거율이 급격히 저하되는 문제점을 개선하고 제거장치의 운전비용을 감소시키기 위한 연구이다. 이를 위해 오염가스 제거에 필요한 라디칼과 이온을 발생시키기 위한 전기방전영역과 연소가스가 흐르는 관로를 분리시킨 플라즈마 반응기를 사용하여 방전불안에 의한 제거효율 저하와 방전선 산회 문제를 개선하여 장시간 운전 가능성을 확인하였고, 또한 운전비용을 감소시키기 위해서는 코로나 방전에 의한 비열플라즈마를 이용하여 연소가스를 산화 변화시키고, 첨가제로 수산화나트륨 수용액 증기와 소량의 암모니아를 사용하였다. 그 결과 암모니아 분자 몰비를 1.5로 하고, 유량이 $2.5{\ell}/min$인 질소가스로 농도가 20%인 수산화나트륨 수용액을 버블링하여 주입하였을 때 질소산화물, 황산화물 제거율이 각각 95, 100%인 우수한 제거특성을 얻었다.