• 전기학회논문지
• /
• 제67권12호
• /
• pp.1577-1586
• /
• 2018

The emergence of the Smart Grid is an integrated solution for the next generation power system that combines IT technology in the power system to create optimal energy utilization and various services. However, these convergence technologies (power systems and information communications) are not only improving the related technologies but also producing various problems especially exposure to cyber risk. In particular, the intelligent power grid has security vulnerabilities through real-time information sharing among various organically linked systems, and it is more complicated than the cyber risk problem in the existing IT field and is directly connected to national disaster accidents. Therefore, in order to construct and operate a more stable smart grid, this paper analyzes the system of power system control system in Korea, and proposes a cyber security element definition and a countermeasure establishment method of power monitoring & control systems based on security standards of smart grid (No. SPS-SGSF-121-1-1).

• 대한임상독성학회지
• /
• 제1권1호
• /
• pp.59-64
• /
• 2003

Objective: This study was conducted for the nationwide statistical survey of poison exposure to provide the rationale for establishing and developing the poison control center (PCC) in Korea. Design: Study group for Korea PCC in National Medical Center reviewed the medical literature on poison exposure of Korea from death reports of National Statistical Office (NSO), the toxic exposure statistics from the report of National Health Insurance Corporation (NHIC), and poison related data from 119 ambulance services (FD) for the purpose of obtaining the poison and its related data. We also conducted questionnaire from the expert who work in emergency medicine department at the designated 320 emergency medical centers in Korea for the preparedness and acknowledgement about necessity of PCC and their need for that. Results: We reviewed the reliable data from the death report of NSO, poison exposure data from NHIC, and running report from FD. Poisoning death occured at home ($36.7\%$) and hospital ($46.3\%$). Poisoning are more common in rural area than the city area. Patients were seen more frequently in the local clinics than in any hospital. The drugs ($45.7\%$) and pesticide ($18.1\%$) are common poison. Common place to poison exposure were residential area ($39.9\%$), industry ($9\%$). mass residential area ($7\%$). and farm ($6\%$). The education level were primary school ($33.2\%$), high school ($23.7\%$), and middle schol ($21.3\%$) in order. We have to provide the poison guideline for lay public to understand easily, and for medical experts. The medical facilities need to be invested and have more interest for toxicology. All medical staff who work in the designated emergency medical center want PCC to establish. They want to have poison information from hospital ($91.3\%$), regional poison information center ($45.0\%$), regional poison control center ($52.5\%$), nationwide poison information center ($48.8\%$), nationwide poison control center ($46.25\%$), as a role of poison control center. They also want that pcc have poison epidemiologic study and statstics, training program for the experts, registration of rare case of posion on website, reflection of policies to activities for antidote production etc., speedy consultation system for poison analysis, public education, establishment of both regional and national pee, etc. Conclusion: Poison center must be established to provide poison information for all the public and medical experitise, focusing rural area and private clinic, to detoxify, to reduce the cost, time, morbity, and mortality through the whole country.

• 한국안전학회지
• /
• 제22권3호
• /
• pp.13-21
• /
• 2007

Personal and static sampling for formaldehyde, wood dust and noise monitoring, in accordance to the equipment running on the day, were carried out throughout wood panel manufacturing process. Even though the exposure level of formaldehyde and wood dust were below than exposure criteria, but the personal protective equipment(PPE) for those should be worn to everyone in the process because of its potential characteristics like carcinogenicity. Also a few local air extraction system above the cutting, grinding sections and organic blending room should be required. Most of the exposures of noise exposure were exceeded permitted exposure criteria, in case of Hopper operators, exposed to maximally 94dB(A) as LAeq 8hr, therefore active controls like PPE, monitoring, isolation etc. are necessary. The main sources of noise were caused on compressed air of the machinery, radio sound and operation noise like running machines, conveying, cutting, sawing, moving vehicles, storing and so on. For the comparison of control criteria in each country, the permitted exposure standards for above hazardous materials and noise in Korea, ACGIH and Australia were discussed. We have recognized that the Korean criteria should be discussed urgently to give the right information to employee and modified, if it is necessary.

• 한국방사선학회논문지
• /
• 제14권5호
• /
• pp.635-642
• /
• 2020

본 연구에서는 자동노출제어장치(automatic exposure control, AEC)의 채광창 차폐정도와 농도, 감도가 관전류량과 영상품질에 미치는 영향을 분석하였다. 실험에 사용된 장비는 X선관과 간접방식의 디지털검출기가 일체형인 디지털방사선발생장치(Digital Diagnost, Philips, Netherlands)를 사용하였다. 채광창 차폐정도는 3 mm 두께의 납을 이용하여 0%부터 100%까지 12.5%씩 순차적으로 누적 차폐하여 9단계로 구분하였다. 농도는 제조사에서 제시한 3단계(+2.5, 0, -2.5)와 감도 3단계(S200, S400, S800)를 대상으로 하였다. 관전류량 평가는 관전압을 40 kVp로 고정하고 AEC 조절인자들이 교차한 81가지의 조합조건에서 자동 노출된 관전류량을 측정하였다. 영상품질평가는 자체 제작한 원뿔형 피라미드 팬텀의 방사선영상을 육안 평가하여 유효한 영상을 선발하였고 이들의 신호 대 잡음비(signal to noise ratio, SNR)을 측정하였다. 그 결과 관전류량은 채광창 차폐정도가 100%, 감도 S200, 농도 2.5일 때 60.0 mAs로 가장 많이 조사되었으며, 채광창 차폐정도가 0%, 감도 S800, 농도 -2.5일 때 0.9 mAs로 가장 적게 조사되었다. SNR은 채광창 차폐정도가 0%, 감도 S200, 농도 2.5일 때 25.2로 가장 우수하였고, 채광창 차폐정도가 25%, 감도 S800, 농도 -2.5일 때 SNR이 4.7로 가장 낮았다.

• 대한디지털의료영상학회논문지
• /
• 제12권2호
• /
• pp.133-138
• /
• 2010

The purpose of this study was to survey and test quality control of mammography system. The conclusion of this study is as follows ; First, The rate of pass for phantom image test shows that Film-Screen mammography system(F/S) and computed mammography system(CR) is 80%, Indirect digital mammography system(DR) is 100%. Second, The test of exposure dose shows that F/S is 921 mR. CR is 1,140 mR, DR is 474 mR. The grade of this testament is CR > F/S > DR. Third, The test of average glandular dose shows that F/S is 1,336 mGy, CR is 1,635 mGy, DR is 1,26 mGy. The grade of this testament is CR > F/S > DR. Fourth, The testament of resolution shows as follows F/S is 11~13 Lp/mm, CR is 4~5 Lp/mm, and DR is 5~7 Lp/mm(F/S > DR > CR) Fifth, The survey of projection, cassette, development and reading shows that user are indifference.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
• /
• pp.500-510
• /
• 1996

A Direct injection -mixing total -flow -control sprayer was developed and evaluated . The system provided precise application rates and minimized operator exposure to chemicals as well as providing a possibility for recycling container so f unused chemicals that can causes environmental contamination. Chemicals were metered and injected proportionally to the diluent flow rate to provide constant concentrations. The main diluent flow was varied in response to changes in travel speed. Experimental variables of the sprayer were the control interval, the sensitivity of flow regulating valve, the tolerance of control object and the sensitivity of the injection pump system. The optimal performance of the flow control system was with an average response time of 8.5 sec at an absolute steady state of error of 0.067 L/min (0.8% of flow rate). The average response time of the injection rate was -0.53 sec and the coefficient of variation (CV) of concentration was 3.2%.

• 반도체디스플레이기술학회지
• /
• 제5권4호
• /
• pp.11-15
• /
• 2006

Expose equipment system that is used for manufacturing process of Flat Panel Display, is most important equipment in whole process. Expose equipment that is for making pattern of mask on substrate, consists of optical part, stage part and transport part. The stage is an important part that aligns mask and substrate for delivering pattern of mask to substrate exactly. In this paper, control system of expose stage that is able to use mask and substrate of diverse size, with PC controller using GUI interface instead of PLC control system. The existing PLC control system does not have the suitable structure for using mask of diverse size. GUI interface integration control system is based on PC. So it has the advantage of convenient use and active operation. We embodied PLC control system in integration control system based on PC, and verified utility possibility through the standard test course.

• 한국발생생물학회지:발생과생식
• /
• 제23권3호
• /
• pp.255-262
• /
• 2019

Previously, we reported negative effects of low-dose nonylphenol (NP) exposure on the reproductive organs of F1 male mice. In the present study was further investigated the endocrine disrupting effect of NP exposure to F2 generation male mice. Mice were divided into 2 groups; (1) CON, control animals and (2) NP-50 ($50{\mu}g/L$), animals were treated with NP via drinking water. NP exposures were continuously conducted from parental pre-mating period until the postnatal day (PND) 55 of F2 offsprings. Mice were sacrificed on PND 55 and the reproductive tissue weights were measured. The initial (at PND 21) and terminal (PND 55) body weights of the NP-50 group animals were not significantly different from those of control group animals. NP exposure fail to induce a significant weight change of the testes, seminal vesicle and prostate except absolute epididymal weight (p<0.05). However, pathohistological studies revealed that NP-treated F2 animals showed evident decrease in seminiferous tubule diameters, reduced luminal area and number of germ cells. Also, sloughing morphologies in the tubules were notable. In the caudal epididymis, fewer mature sperms and swollen epithelial cells were found in the NP-treated group. The present study demonstrated that the subchronic low-dose NP exposure induced pathohistological abnormalities in testis and epididymis of F2 mice, and we assumed that these 'qualitative' changes in reproductive tissues could be derived from the epigenetic modifications such as DNA methylation, histone modification, altered DNA accessibility and chromatin structure. Further studies are needed to achieve a better understanding on the multi- or trans-generational effects of NP on the reproductive health and a human application.

• 한국산업보건학회지
• /
• 제25권3호
• /
• pp.346-354
• /
• 2015

Objectives: This study was conducted to evaluate the changes and regional differences of mortality and morbidity particularly respiratory system diseases in the area of exposure to coal dust(Ansim area, Dong-gu, Daegu). Methods: The authors analyzed secondary data(cancer registration data, mortality data, and health insurance data) for respiratory system diseases. We calculated age standardized incidence ratio(SIR), mortality ratio(SMR), and health care utilization ratio(SHR) using those data. Results: There were no significant differences between Ansim area(or Dong-gu, Daegu) and the control area for cancer registration data and mortality data. In the results for the health insurance data, significant increased SHR in asthma was observed compared to the control area. Conclusions: Although confounders such as selection bias were not clearly ruled out, our findings reveal increased asthma SHR in the area of exposure to coal dust. Further prospective studies are required to clarify the increasing respiratory disease due to exposure to coal dust.

• 한국산업보건학회지
• /
• 제19권3호
• /
• pp.280-287
• /
• 2009

High-tech microelectronics industry is known as one of the most chemical-intensive industries. In Korea, Microelectronics industry occupied 38% of export and 16% of working employees work in microelectronics industry. But, chemical information and health hazards of high-tech microelectronics manufacturing are poorly understood because of rapid development and its penchant for secrecy. We need to investigate on chemical use and exposure control. We Site-visits to 6 high-tech microelectronics manufacturing company which have cleanroom work using over 1,000kg organic solvents (5 semi-conductor chips and its related parts company, 1 liquid crystal display (LCD)). We reviewed their data on chemical use and ventilation system, and measured TVOCs (Total Volatile Organic Compounds) and carbon dioxide concentration. All cleanroom air passed through hepa filters to acheive low particle levels and only 1 cleanroom uses carbon filters to minimize the organic solvents exposures In TVOC screening test, Cleanroom for semi-conductor chips and its related parts company with laminar down flow system (e.g. class 1~100) showed nondetectable level of TVOCs concentration, but Cleanroom for liquid crystal display (LCD) with conventional flow system (e.g. class 1,000~10,000) showed 327 ppm as TVOCs. Acetone concentration in cleanroom for Jig cleaning, LC Injection, Sealing processes were 18.488ppm (n=14), 49.762 ppm (n=15), 8.656 ppm (n=14) as arithmetric mean. Acetone concentration in cleanroom for LCD inspection process was 40ppm (n=55) as geometric mean, where the range was 7.8~128.7ppm and weakly correlated with ventilation rate efficiency(r=0.44, p<0.05). To control organic solvents in cleanrooms, chemical and carbon filters should be installed with hepa filters. Even though their volatile organic compounds concentration was not exceed to occupational exposure limits, considering of entrance limited cleanroom environment, long-term period exposure effects and adverse health effects of cleanroom worker need further reseach.