• 한국환경보건학회지
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• 제42권3호
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• pp.141-146
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• 2016

In South Korea, many cases of humidifier disinfectant-associated lung injury (HDLI) have been reported among people who used humidifier products containing humidifier disinfectant (HD). The objectives of this study are to estimate both airborne HD concentration in the room where HD was used and the amount of humidifier disinfectant absorbed into the respiratory system. Information and data on the HDs were collected using a structured questionnaire and home environmental investigations include the volume of HD (ml) and hours used per day, concentration of disinfectants contained in the HD brand (${\mu}g/ml$), volume of the room ($m^3$), assumed ventilation rate ($m^3/hr$) and breathing rate assumed ($m^3/hr$). We used children aged under five years old as a sample and estimated both airborne HD concentrations and amount of HD absorbed into the respiratory system. The estimated airborne concentration of HD in the room ranged from 68 to $369{\mu}g/m^3$ for PHMG (polyhexamethylene guanidine phosphate) and from 16 to $239{\mu}g/m^3$ for PGH (oligo (2-(2-ethoxy) ethoxyethyl guanidine). The amount of HD absorbed in the respiratory system per day was estimated to range from 227 to $1,225{\mu}g$ for PHMG and from 53 to $794{\mu}g$ for PGH. In conclusion, a great amount of HD was likely absorbed into respiratory system, likely beyond the level of the capacity of the immune system to remove the HD absorbed.

• 한국산업보건학회지
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• 제16권4호
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• pp.334-345
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• 2006

The objectives of this study were to analyze and compare 24 hrs personal exposure levels of MF at microenvironments such as home, school, educational institute, internet pc game room, transportation, and other places according to time activity patterns using various metrics for children attending the primary schools located near and away from the power lines, and to characterize the major microenvironments and impact factors attributed personal exposure level. The study was carried out for 44 children attending a primary school away from the lines(school A) and 125 children attending a school away from 154 kV power lines(school B), all who aged 12 years and were 6 grade, from July 2003 to December 2003. All participants filled in a questionnaire about characteristics, residence, use of electrical appliances and others. Children wore a small satchel in which EMDEX II and Lite (Enertech, Co. Ltd) and a diary of activity list for period of registration in 20 minutes blocks. All statistical calculations were made with the SAS System, Releas 6.12. The summary of results was presented below. First, about the characteristics of subjects, there no differences between two groups. The subject almost spent about 56 % of their time at home and about 20~25 % of their time at school. Fifty percent of children spent 2 hours at private educational institutes. Second, the personal exposure measurements of children in school B was statistically higher than those of children in school A by various metrics such as arithmetic mean, geometric mean, percentile(5, 25, 50, 75, 95), maximum, rate of change metric, constant field metric. The arithmetic and geometric mean magnetic fields during the time the children were at school B were 0.98 and $0.86{\mu}T$ and were about 23 times higher than those of children were at school A. In conclusion, the significant major determinants of personal exposure level is the distance from the power line to microenvironments.

• 보건교육건강증진학회지
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• 제16권1호
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• pp.101-126
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• 1999

As the WTO system launches through the agreement of Uruguay Round, the Government has to revise the office regulations or reform the system. Also, Integrating and Coordinating the like affair in health care (i. e., children's home, industry health, school health, health manpower, the administration of health center, the administration on food hygiene, health environmental education, and so on.) which is now scattered into some government departments like the Ministry of Labor, the Ministry of Education, the Ministry of Home Affairs, the Ministry of Agriculture, and the Ministry of Environment, the Government has to prevent unspecialty, inefficiency, inconsistency, and uneconomy. The Government has to review and adopt above suggested the Proposal 1),2),3),4) of the Health Centers on the basis of the local autonomy law and it will help the successive settlement of the local autonomy system in Korea. According to the suggested proposal, the Central Government mainly takes charge of the Macro affairs as hardware, and transfer the Micro affairs as software into the Local Governments to attempt the appropriate functional allocation. To achieve it successfully, the Central Government also has to do the financial support, manpower training and technical support, allocation of health care resources, direction and control, research and development and the health care plan on the macro level. Local Governments which divided into the wide local government and basic local government also have to do their best for health improvement of the community societies like plan of health care program, implementation of health care service program, taking charge of the affairs of health insurance, activation of community residents' participation and security of health care resources etc. To achieve this goal, the Government have to be more active and reformative, the related social and health agencies and educational agencies have to cooperate and support for the goals, and especially, the community residents have to participate actively and voluntarily, When all these conditions promote, local health care administration will be developed, and health level of community residents will be secured. And going one step forward, the country and people will be more healthy

• 한국환경복원기술학회지
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• 제2권1호
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• pp.10-19
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• 1999

In 1991, the ministry of Gov't. Administration and Home Affairs set up a minimum of one sewage disposal plant in each province. By 1995, 264 models of the capillary infiltration method were set up in 331(78%) villages and the contact oxidation method was set up in 52 places. Since the Gov't. sent a letter to each responsible officer across the country stating their disapproval of the capillary infiltration method, the environmentally friendly sewage disposal system has not been diffused. The current model(mechanical sewage disposal) being used, in agricultural and fishing villages, costs too much for maintenance and operation(\50,000 per capita per year). In particular, because of the difference in sewage characteristics of agricultural and fishing villages from urban sewage, the efficiency of the disposal system is very low. Also, because of the growing need for more disposal plants, the Gov't. is looking for cheaper alternatives. This study has analyzed 2 kinds of sewage disposal. The first is used widely in agricultural and fishing villages in Germany. The second is used widely in similar areas of Korea. It has intended to analyze the characteristics, merits and defects of the sewage disposal water plants and pebbles model which is used widely in Germany and developed compatibly for Korea.

• 한국환경보건학회지
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• 제40권5호
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• pp.397-406
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• 2014

Objectives: Perchloroethylene (PCE) is a volatile chemical widely used as a solvent in the dry-cleaning and textile processing industries. It was evaluated as Group 2 "probably carcinogenic to humans" by the Integrated Risk Information System (IRIS) of the United State Environmental Protection Agency (U.S. EPA) in 2012. In order to provide a scientific basis for establishing risk management measures for chemicals on the national priority substances list, aggregate risk assessment was conducted for PCE, included in the top-10 substances. Methods: We conducted the investigation and monitoring of PCE exposure (e.g., exposure scenario, detection levels, and exposure factors, etc.) and assessed its multi-media (e.g., outdoor air, indoor air, and ground water) exposure risk with a deterministic and probabilistic approach. Results: In human risk assessment (HRA), the level of human exposure was higher in the younger age group. The exposure level through inhalation at home was the highest among the exposure routes. Outdoor air or uptake of drinking water represented less than 1% of total contributions to PCE exposure. These findings suggested that the level of risk was negligible since the Hazard Index (HI) induced by HRA was below one among all age groups, with a maximum HI value of 0.17 when reasonable maximum exposure was applied. Conclusion: In conclusion, it was suggested that despite low exposure risk, further studies are needed considering main sources, including occupational exposure.

• 한국멀티미디어학회논문지
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• 제19권2호
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• pp.405-410
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• 2016

Elevator industry is a field that is mechanical, electrical and electronic technology and constantly requires inspection and maintenance considering various applications and various types. Recently, various elevator control and monitoring technologies with IT are developing for elevators on land. But technologies with IT have been hardly done in marine elevator that is consistently assured safety and reliability of life cycle for its parts in poor environment. In this paper, we implemented embedded main controller, floor controller and car controller that meet the requirements and use NMEA network protocol by analyzing home and abroad integrated elevator operation and management systems. Especially, we secured reliability of maintenance by real-time fault diagnosis and control that was implemented with limit switch, gyro sensor, temperature/humidity/barometric pressure sensor and fire detection sensor thinking over the environmental conditions of terrestrial and marine elevator.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.687-691
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• 2001

With today's global environmental and energy problems, high expectations exist for solar power generation to reduce carbon dioxide generated by the consumption of fossil fuels. On the other hand, power consumption in residential homes is increasing every year. Among the many household appliances, the power demand for air conditioners increases dramatically during the summer, particularly in the afternoons. As this pattern closely matches the output pattern of solar cells, it should be possible to combine a photovoltaic array with an air conditioner to decrease the energy consumption within the home. We have developed a residential solar-powered air conditioner that operates through a combination of photovoltaic array and commercial power. In this paper, the configuration and specification of the residential solar-powered system are described to a novel high efficiency inverter using a ZVCS boost converter. And the performance evaluations of the solar-powered air conditioner are examined by the analysis of a new tracking controller with a maximum power $P_{max}$ detection of solar cell.

• 경영과학
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• 제33권3호
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• pp.1-18
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• 2016

Recently, ordinary mail is decreasing continuously by the development of ICT (Information and Communications Technology) including E-mail, messenger service, and etc. On the contrary, parcel post is increasing by the increase of online shopping, home shopping, and etc. Aside from these changes, the demand for various mail acceptance and delivery means is increasing with the increase of single households and dual-income couples. To overcome these environmental changes, Korea Post installs unmanned post offices which are composed of various unmanned mail acceptance and delivery postal systems. In this paper, we propose the methodological approach for the site selection of unmanned post office among the existing post offices and the installation standard of unmanned postal system considering the operation cost by the mail volume.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.948-951
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• 2008

Ubiquitous sensor network (USN) based on ZigBee communication protocol has been used in various application fields, such as home-network, intelligent building and machine, logistics, environmental monitoring, military field, security field and etc. The ZigBee is targeted at radio-frequency application that require a low data rate, long battery life and secure network. Especially, the USN system can be applied efficiently to building-indoor where the complex geometry is adopted. In this study, all 90 points of railway cabin indoor were monitored for temperature and humidity using USN technology. All sensors were pre/post-calibrated and the temperature/humidity change were analyzed in a railway cabin in real-time. The results would be useful to develop the cabin heating, ventilating and air conditing (HVAC) system to meet all passengers' thermal comfort regardless of their seat position.

• 가정과삶의질연구
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• 제8권2호
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• pp.147-162
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• 1990

The purpose of this review is to establish a groundwork for building a more comprehensive conceptual framework within which various aspects of sibling relations and factor related to sibling behaviors con be explained and integrated. Descriptions of the trends and shifts in sibling studies are made in terms of their themes, variables, basic perceptions and general approaches, and analyzes of current state of sibling researches are made with relation to the conceptual aspects of the studies, namely, their standpoints on the issues of sibling variations, the sources of variations, and basic units of analysis, their reliance or emphasis on different methods, and their interests in the mediation processes. It is recognized that research variables have been successively differentiated and used in diversified manners and family ecology and systems theory viewpoints have been incorporated into the understanding of sibling relations. A triad in its full meaning, rather than a dyad or a partial trial, is proposed as a unit of analysis in order for the researchers to be able to examine and describe the true interactional aspects of family relations involving sibling relations. The concepts of coexistence and interaction are proposed as key concepts os that the inconsistencies in findings, differing viewpoints, contradicting conceptions , and contrasting approaches can be interpreted and integrated into a unified system of theories on siblings. The coexistence of similarities and differences in reality. the inevitability of interaction between individual variables and environmental variables and between within-family environmental factors and our-of-family environmental factors, and the need for the joint use of intrafamilial and extrafamilial approach are acknowledged. Attention is also drawn to the mechanism characteristics and the directionality of the mediating processes of mediating variables between a variable and its effects.