• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.57-68
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• 2018

A system to prevent disasters by collecting and analyzing environmental information such as road surface sedimentation, sinkholes, collapse risk of bridges, temperature and humidity around tram station is continuously monitored by monitoring the condition of road surface when constructing tram which is one of the urban railways. In this paper, we propose a wireless network security management system for tram roads based on LPWA that can recognize risk factors of road surface, bridge and tram station of tram in advance and prevent risk. The proposed system consists of a sensor node that detects the state of the tram road surface, a gateway that collects sensor information, and a safety management system that monitors the safety and environmental conditions of the tram road surface, and applies the low power long distance communication technology. As a result of comparing the proposed system with the LTE system in the field test, it was confirmed that there is no significant difference between the sensor information value and the critical alarm level in the monitoring system.

• Journal of Ecology and Environment
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• v.41 no.10
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• pp.290-301
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• 2017

Background: Forest edges create distinctive ecological space as adjacent constituents, which distinguish between different ecosystems or land use types. These edges are made by anthropogenic or natural disturbance and affects both abiotic and biotic factors gradually. This study was carried out to assess edge effects on disturbed landscape at the pine-dominated clear-cut area in a genetic resources reserve in Uljin-gun, eastern Korea. This study aims to estimate the distance of edge influence by analyzing changes of abiotic and biotic factors along the distance from forest edge. Further, we recommend forest management strategy for sustaining healthy forest landscapes by reducing effects of deforestation. Results: Distance of edge effect based on the abiotic factors varied from 8.2 to 33.0 m. The distances were the longest in $Mg^{2+}$ content and total nitrogen, $K^+$, $Ca^{2+}$ contents, canopy openness, light intensity, air humidity, $Na^+$ content, and soil temperature followed. The result based on biotic factors varied from 6.8 to 29.5 m, coverage of tree species in the herb layer showed the longest distance and coverage of shrub plant in the herb layer, evenness, species diversity, total coverage of herb layer, and species richness followed. As the result of calculation of edge effect by synthesizing 26 factors measured in this study, the effect was shown from 11.0 m of the forest interior to 22.4 m of the open space. In the result of stand ordination, Rhododendron mucronulatum, R. schlippenbachii, and Fraxinus sieboldiana dominated arrangement of forest interior sites and Quercus mongolica, Vitis amurensis, and Rubus crataegifolius dominated spatial distribution of the open area plots. Conclusions: Forest interior habitat lies within the influence of both abiotic and biotic edge effects. Therefore, we need a forest management strategy to sustain the stability of the plant and further animal communities that depend on its stable conditions. For protecting forest interior, we recommend selective logging as a harvesting method for minimizing edge effects by anthropogenic disturbance. In fact, it was known that selective logging contributes to control light availability and wind regime, which are key factors affecting microclimate. In addition, ecological restoration applying protective planting for the remaining forest in the clear-cut area could contribute to prevent continuous disturbance in forest interior.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.1-11
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• 2019

The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) predicted that recent extreme hydrological events would affect water quality and aggravate various forms of water pollution. To analyze changes in water quality due to future climate change, input data (precipitation, average temperature, relative humidity, average wind speed and sunlight) were established using the Representative Concentration Pathways (RCP) 8.5 climate change scenario suggested by the AR5 and calculated the future runoff for each target period (Reference:1989-2015; I: 2016-2040; II: 2041-2070; and III: 2071-2099) using the semi-distributed land use-based runoff processes (SLURP) model. Meteorological factors that affect water quality (precipitation, temperature and runoff) were inputted into the multiple linear regression analysis (MLRA) and artificial neural network (ANN) models to analyze water quality data, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (T-N) and total phosphorus (T-P). Future water quality prediction of the Anseongcheon River basin shows that DO at Gongdo station in the river will drop by 35% in autumn by the end of the $21^{st}$ century and that BOD, COD and SS will increase by 36%, 20% and 42%, respectively. Analysis revealed that the oxygen demand at Dongyeongyo station will decrease by 17% in summer and BOD, COD and SS will increase by 30%, 12% and 17%, respectively. This study suggests that there is a need to continuously monitor the water quality of the Anseongcheon River basin for long-term management. A more reliable prediction of future water quality will be achieved if various social scenarios and climate data are taken into consideration.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.595-603
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• 2017

Crop growth and production cost are greatly influenced by management of environmental factors such as ambient temperature, humidity, and $CO_2$, especially in protected horticulture. Opening and closing of greenhouses is the most important operation for control of these ambient environmental factors, and precise and stable operation requires high performance window motors. In this study, a 400 W precise window motor was constructed, and its performance was evaluated for plastic and glass greenhouses. First, the motor was designed and fabricated by benchmarking of an advanced foreign product. Then, the performance was evaluated through vibration, PCB (Process Control Block), and load tests. Vibration tests resulted in averaged vibration displacement and velocity of the developed motor of 0.002 mm and 0.2267m/s, which were statistically significantly different from those of the target motor. Average vibration acceleration ($0.26m/s^2$) of the developed motor was also significantly different from that ($0.51m/s^2$) of the target motor. PCB tests showed 2 - 4 mm deviation from the target values, and confirmed the operating status and precision of the control. Load tests with a 300 kg load also showed acceptable operating status and durability. Current values were $1.31{\pm}0.06A$ and RPMs were in the range of 2.9 - 3.0. Considering the above results, the developed window motor would be competitive to the target foreign product.

• Korean Journal of Human Ecology
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• v.17 no.6
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• pp.1215-1224
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• 2008

This research has measured the indoor environment of thirty hair salons, which are located on Gunsan-Si, Jeonlabbuk-Do, from April 1st to April 30th 2005, to examine the related factors on a work environment of hairdressers and a revelation of respiratory symptom, and has polled 260 hairdressers and 350 office workers. After measuring the physical environment of hair salons, the room temperature, the relative humidity and the illumination was in an agreeable range, and 60 percent of hair salons depended on the natural ventilation through the windows. The levels of acetone, toluene and xylene, which were measured at the hair salons, were all under the safety standards (p<0.05), but these are still harmful and volatile matters, so they can be bad for your health by the contact of skin and respiration. The harmful factors that affect a revelation of respiratory symptom were the group who has many exposures of permanent wave or bleaching/dyeing and not many experiences of hairdressing work, the group who smokes every day, and the group who never exercises at all (p<0.05). This result shows that there are possibilities of health problem for hairdressers from the constant and repeating hairdressing works with the exposure of chemicals such as the permanent, bleaching and dyeing. so that hairdressers recognize that they need appropriate ventilation facilities for their agreeable indoor-environments. And also, to prevent the direct exposure of chemicals as much as they can, they need to have an active management of an individual health care by wearing gloves, mask or something like that.

• Journal of Korean Society of Archives and Records Management
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• v.3 no.2
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• pp.143-155
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• 2003

As archives, photograph is the evident records of historical facts and experiences. Thus, it is worth preserving. Unlike other documents silver halide photographic films and prints are quite sensitive to environmental factors such as light, temperature and humidity, which demands careful treatment in preservation. This study was carried out to select popular photographic films and papers on the market, to examine their photographic speeds (or sensitivities) and to compare and analyze their preservative features after keeping them some time in a weather-o-meter. Consequently, B/W materials were superior to color ones in preservation. And films were better than papers in the same manner. But we were not able to observe remarkable differences among material's manufacturers.