• Journal of Korean Society for Atmospheric Environment
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• v.24 no.3
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• pp.300-309
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• 2008

Variations in PM10 concentration between 2000 and 2005 from 84 urban air monitoring stations operated by the government were analyzed. The K-means cluster analysis was attempted using annual average and the 99th percentile of daily averages as parameters. The results obtained by excluding Asian dust episode days were compared with those obtained by using all available data. In any cases, the cluster with the highest mean concentration was mostly composed of stations in Seoul and Gyeonggi. Annual average of the cluster with the highest mean concentration showed a distinct decreasing trend, but that excluding Asian dust episode days did not show such a trend. Without Asian dust episode days high concentrations of monthly averages in March and April were also not observed. The effect of Asian dust was more pronounced in the 99th percentile of daily averages. The 99th percentile of daily averages of the cluster with the highest mean concentration was the highest in June following downs in April and May.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.585-592
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• 2015

In this study, by applying mobile based GIS and image analysis of particulate matter ($PM_{10}$) concentration in Seoul and Ulsan in Korea, to identify the user's location and also implemented the application to information exchange. It strengthened citizens' access to air quality information through the application and derived the expanded environment information sharing through real-time user participation. Through atmospheric concentrations image analysis, it showed a new environmental information construction possibility. It had the effect of expanding the information collecting through the local user participation on the limited information collected area which place is not yet constructed atmospheric monitoring network. Location-based particulate matter information service application provides a user location's $PM_{10}$ information from the 25 urban air monitoring network real-time database of the Ministry of Environment. Furthermore, if the user sent a picture of the atmosphere to the server, should match the image density values of the database and express on Seoul's maps through the IDW interpolation. And then a $PM_{10}$ concentration result is transmitted to user in real time.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.83-88
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• 1998

Filter badge type sampler has not been widely used to evaluate air quality over large cities in Korea while it can be successfully used for multi-point sampling and analysis. We evaluated the passive sampler as a new tool to monitor air quality over large cities. We latticed Metropolitan Seoul into $2{\times}2Km$ to give 136 points. $NO_2$ concentrations were measured at all the points in the Spring and Summer of 1997. According to the passive sampler data, natural green zones generally recorded lower $NO_2$ concentrations than major streets and traffic congestion areas. Passive samplers with abundant 136 points gave more detailed picture of $NO_2$ distribution while auto-monitoring network did not clearly provide the characteristics of local land use. Also, passive samplers gave 15% higher values than auto-monitoring network. The correlation between the two values appears very high judging from the regression slope of 0.92 and correlation coefficient of 0.91. This study clearly demonstrates the effectiveness of the passive sampler as a tool to monitor air quality over large cities.

• Particle and aerosol research
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• v.16 no.2
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• pp.31-47
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• 2020

Although interest in air quality has increased due to the frequent occurrence of high-concentration fine particulate matter recently, the official fine particulate matter measuring network has failed to provide spatial detailed air quality information. This is because current measurement equipment has a high cost of installation and maintenance, which limits the composition of the measuring network at high resolution. To compensate for the limitations of the current official measuring network, this study constructed a spatial high density measuring network using the fine particulate matter simple measuring device developed by Observer, W-Station. W-Station installed 48 units on Jeju Island and measured PM_2.5 for six months. The data collected in W-Station were corrected by applying the first regression equation for each section, and these measurements were compared and analyzed based on the official measurements installed in Jeju Island. As a result, the time series of PM_2.5 concentrations measured in W-Station showed concentration characteristics similar to those of the environmental pollution measuring network. In particular, the results of comparing the measurements of W-Station within a 2 km radius of the reference station and the reference station showed that the coefficient of determination (R²) was 0.79, 0.81, 0.67, respectively. In addition, for W-Station within a 1 km radius, the coefficient of determination was 0.85, 0.82, 0.68, respectively, showing slightly higher correlation. In addition, the local concentration deviation of some regions could be confirmed through 48 high density measuring networks. These results show that if a network of measurements is constructed with adequate spatial distribution using a number of simple meters with a certain degree of proven performance, the measurements are effective in monitoring local air quality and can be fully utilized to supplement or replace formal measurements.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1205-1210
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• 2004

The 4-20mA analog signal used in the various industrial fields to interface sensor in distributed process control has been replaced with relatively simple digital networks, called "fieldbus, and recently by Ethernet. Significant advances in Internet and computer technology have made it possible to develop an Internet based control, monitoring, and operation scheduling system for heating, ventilation and air-conditioning (HVAC) systems. The seamless integration of data networks with control networks allows access to any control point from anywhere. Field compatible field devices become so-called "smart" devices, capable of executing simple control, diagnostic and maintenance functions and providing bidirectional serial communication to higher level controller. The most important HVAC of BAS has received nationwide attention because of higher portion of more than 40% in building sector energy use and limited resources. This paper presents the Internet-based monitoring and control architecture and development of LonWorks control modules for AHU (air handling units) of HVAC in viewpoint of configuring BAS network. This article addresses issues in architecture section, electronics, embedded processors and software, and internet technologies.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.399-400
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.187-188
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2010.04a
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• pp.489-490
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• 2010

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.1
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• pp.47-54
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• 1987

A new method for designing air pollution monitoring newtork is presented in this study. In this method, the magnitudes and the correlation coefficients of predicted concentrations in each grid points are examined and the monitoring stations are assigned to those stations which cover the damage cost the most. This method was applied to the Ulsan-Onsan Industrial Complex. This method turned out to be much more efficient than the method of TM coordinates and the method of concentric circles prescribed in the Standard Methods for Pollution Measurement as well as the existing monitoring system established in the area. The 21 stations selected by the method of TM coordinates could cover only 64.4% of the damage cost in the area, the 16 stations by the method of concentric circles 72.1%, and the existing 21 stations 67.8%, while 11 stations were enough to cover 90% of the damage cost in the area with this method. It also was found that this method required only 24 stations to cover the entire area.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.117-121
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• 2015

$O_2$-deficiency related accidents occur every year and the most effective way to prevent them is to measure $O_2$ concentration in air with a properly-calibrated $O_2$ monitoring device before entering low-$O_2$ areas. An electro-chemical sensor, Texas Instrument gas platform, and iPhone are used to construct a smartphone-based $O_2$ monitoring device. The smartphone based $O_2$ measuring approach offers advantages of small size, accessibility, internet-connectivity, and programmability in comparison to conventional $O_2$ measuring devices. Multiple gas sensors can be conveniently interfaced to single smartphone, allowing for creating a network of gas sensors distributed across workplaces and remote monitoring via existing mobile communication network. To check proper function of the $O_2$ monitoring device the sensor was exposed to shallow and deep human breaths. The readings decreased immediately after being exposed to exhalation and recovered during inhalation to a calibrated level of 20.9%. When readings decreased below a preset warning value of 19.5%, a low $O_2$ warning was successfully activated on the smartphone.