• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.175-187
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• 2014

The subways play an important part in serious traffic problems. Almost seven million citizens a day are using subways as a means of traffic communication in the Seoul metropolitan city in 2012. However, the subway system is a semi-closed environment, so many serious problems occurred in subway stations and injured passengers' health. Platform screen doors (PSD) are expected to prevent negligent accident such as injury or death from falling and improve the air quality of the subway station. Installation of PSD at stations in Seoul metropolitan subway had been completed in December 2009. Consequently, the underground transportation system became a closed environment, so the air quality has improved the platforms, but it has deteriorated in the tunnels. Especially, the subway cabin has many doors, and the doors are frequently opened and closed. For this reason, the effect of door opening on subway cabin, dust flow inside the subway cabin. In this process, the maintenance work may influence the health of people who work underground, as well as that of subway users (passengers). In this study, we measured air quality inside and outside of the subway cabin line 2 in Seoul, Korea. This study focused on the investigation of Indoor Air Quality (IAQ) and measurement target pollutants are PM10, CO, $CO_2$, $NO_2$, $O_3$. It was found that levels of PM10, $CO_2$, and $NO_2$ inside subway cabin line 2 exceeded the Korea IAQ standard. Concentrations of PM10, $CO_2$, and $NO_2$ inside of the cabin are higher than outside of the cabin (Indoor Outdoor ratio is higher than 1.). Concentrations of CO, $O_3$ inside of the cabin are lower than outside of the cabin (Indoor Outdoor ratio is lower than 1.). There is a high correlation between $CO_2$ and passengers inside of the cabin and PM10 is only the weakest correlation with passengers. Therefore, it is important to find out the emission source of $NO_2$. The results of this study will be useful as fundamental data to study indoor air quality of a subway cabin.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.113-120
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• 2009

Through the automatic sensing of the environment, USN technology can give the best services. In this work, we have developed an active RFID system and examined its performance. By implementing it into water quality sensors, we constructed a system that can detect diverse indoor/outdoor environment and provide information about the pollution level obtained from the temperature and PH sensors. Our RF system had an internal Print-on-PCB antenna for the miniaturization of the tag. We used a RF transceiver CC2510 chipset of TI company to realize the active RFID function. By using RSSI constants obtained, we performed the evaluation of real time location accuracy with a software written in Labview. Among 10 arbitrary locations, we obtained average measurement errors of 1.69 m in x axis and 1.66 m in y axis. This technology can be applied to logistics, environmental monitoring, prevention of missing children and various applications.

• Journal of Internet Computing and Services
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• v.17 no.1
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• pp.35-45
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• 2016

Melatonin hormone involved in human's circadian rhythm adjustment sensitively responds to light's specific short wavelength ratio. A shift worker's circadian rhythm disturbance and sleep disorder are caused by the existing lighting conditions, whose short wavelength ratio is fixed. The life pattern of a shift worker changes irregularly because of irregular working hours and the same lighting environment; thus, his/her concentration is reduced. For such a reason, negative effects ensue to the detriment of healthy everyday life, including a high risk of accidents or having unsound sleep after leaving work. A smartphone-based wavelength control LED lighting system that targets shift workers and that can easily measure and control lighting suitable for wake-sleep cycle, according to working hours and closing hours, is proposed in this paper. First, after the light characteristics of LED lighting that changes depending on light control ratio are measured through the color sensor installed on the smartphone and the externally-linked Mini-Spectrometer, they are stored in the database. Based on the stored optical characteristics data, the measurement module and light control module are implemented. Lighting is offered using a control ratio having the maximum rate of short wavelength in consideration of the target illuminance, classified according to work type by identifying working hours as time when waking is required for shift workers. After a shift work leaves work, the amount of lighting is varied, using a control ratio having a minimum short wavelength rate so that a shift worker can enter the sleep state naturally.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.5
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• pp.354-365
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• 2015

This work presents an Internet of Things (IoT) system for home energy management based on a custom-designed Impulse Radio Ultra-Wideband (IR-UWB) transceiver that targets a generic and multi-standard control system. This control system enables the interoperability of heterogeneous devices: it integrates various sensor nodes based on ZigBee, EnOcean and UWB in the same middleware by utilizing an ad-hoc layer as an interface between the hardware and software. The paper presents as a first the design of the IR-UWB transceiver for a portable sensor node integrated with the middleware layer, and also describes the receiver connected to the control system. The custom-designed low-power transmitter on the sensor node is fabricated with 130 nm CMOS technology. It generates a signal with a 1.1 ns pulse width while consuming $39{\mu}W$ at 1 Mbps. The UWB sensor node with a temperature measurement capability consumes 5.31 mW, which is lower than the power level of state-of-the-art solutions for smart-home applications. The UWB hardware and software layers necessary to interface with the control system are verified in over-the-air measurements in an actual office environment. With the implementation of the presented sensor node and its integration in the energy management system, we demonstrate achievement of the broad flexibility demanded for IoT.

• Journal of People, Plants, and Environment
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• v.21 no.6
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• pp.461-471
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• 2018

The role of urban agriculture should not be limited as a small-scale crop cultivation activity as it was, but it has to be considered as an entire process of a agriculture activity for the restoration of the city community. This study is based on the assumption that there has been a significant change in urban lifestyle and urban farming preference, considering the overall improvement in standard of living after implementation of five day work week system. It was conducted for urban citizens who were interested in actual urban agriculture for ages 19 and over who visited the Korea Urban Agriculture Exhibition in 2018. Only 115 valid samples were used for the empirical analysis. To analyze the demographic characteristics and effects of urban agriculture, frequency analysis and descriptive statistics were conducted. In order to analyze the reliability and validity of the measurement variables of the effect, the variables that deteriorate the validity were removed and 15 variables of the urban agricultural effect were selected. According to the result of factor analysis, three factors were extracted as follows: socially sustainable effect, negative effect and economically sustainable effect. In order to examine the effects of urban agriculture depending on income level, the one-way ANOVA, which is a statistical technique for verifying differences in the sample means, was performed. The psychological stability of people, the recovery of humanity through communion with nature, and the vitalization of agriculture linked with local agriculture had significant correlations with income level. The negative effect showed no significant correlation with income level. The improvement of the local environment was found to have an impact in relation with income level. We expect that there will be more studies on policies for the new types and models of urban agriculture in order to make it easier for urban citizens to approach it.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.1
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• pp.11-19
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• 2013

Backgrounds: Occupations are grouped on the basis of similarity in tasks and duties performed. Standard occupational classification (SOC) is a tool for organizing all professions into a clearly defined set of groups according to the tasks and duties undertaken in the respective jobs. Objectives: The major objective of this study is to comprehensively review how a SOC system is used in occupational and safety fields such as surveillance, exposure monitoring, occupational epidemiological study, management of carcinogens and analysis of occupational accidents. Methods: We summarized the cases, policies and regulations used in SOC systems in advanced countries and as they appear in articles Results: We found that SOC systems have been widely used in various areas of occupational safety and health in the US, the UK, Finland, and the EU. In general, it is highly common to use SOC in the analysis of occupational accidents and diseases and to identify factors causing those accidents. The SOC system is also used not only for surveillance of exposure to hazardous agents and occupational health, but to manage carcinogens. In order to adjust the effects of a particular job, SOC is used in the general population health area. The Ministry of Employment and Labor (MOEL) has never used or introduced an SOC system. There have been no cases of the application of a SOC system to either the occupational safety and health field or to health surveillance for the general population in Korea. Conclusions: We suggested a need to introduce an SOC system in several occupational safety and health activities, such as work environment measurement, analysis of occupational accidents, specific physical examination and surveillance systems, etc.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.213-226
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• 1993

The purpose of this study is to computerize the design of single source for a duct work system which is essential for the improvement of working places. There are different types of hood, such as general hood, push pull hood and canopy hood. And out of these three types, general hood and canopy hood were used as subjects of this study. The software used here was Quattro Pro 123 programm, and the hardware was IBM PS/SX(type 5510-SK4 S/N 83-05164). And the results are tabulated in