• Journal of Soil and Groundwater Environment
• /
• v.19 no.3
• /
• pp.39-46
• /
• 2014

Hydraulic conductivity is an important parameter, representing permeable property of the groundwater in aquifers, in the issues of groundwater development, groundwater contamination, and groundwater flow, etc. We estimated a relationship between hydraulic conductivity and electrical properties (formation factor, chargeability, and time constant) of silty sand in the laboratory. For this study, we conducted grain size analysis, constant head permeameter test, and measured electrical resistivity and spectral induced polarization of silty sand samples collected from the riverside alluvium of the Nakdong River in Nogok-ri area, Dasan-myeon, Goryeong-gun in Gyeongbook Province, Korea. In the laboratory test, we used soil samples of approximately uniform porosity with 0.5% error range, and kept the electrical resistivity of pore water with 100 ohm-m. As a result, the relationship between effective particle size and hydraulic conductivity agrees fairly well with the existing empirical formulas. Hydraulic conductivity was correlated with formation factor, chargeability, and time constant: hydraulic conductivity increased with increasing formation factor and time constant as well as with decreasing chargeability.

• Geomechanics and Engineering
• /
• v.28 no.1
• /
• pp.77-87
• /
• 2022

Many geotechnical analyses require the investigation of water flow within partially saturated soil zone to incorporate the effect of climatic conditions. It is widely understood that the hydraulic properties of the partially saturated soil should be included in the transient seepage analyses. However, the characteristics of dual porosity soils with dual-mode water retention curve are normally modelled using single-mode mathematical equation for simplification of the analysis. In reality, the rainwater flow can be affected significantly by the dual-mode hydraulic properties of the soil. This paper presents the variations of safety factor for dual porosity soil slope with dual-mode water retention curve and dual-mode unsaturated permeability. This paper includes the development of the new dual-mode unsaturated permeability to represent the characteristics of soil with the dual-mode water retention curve. The finite element analyses were conducted to examine the role of dual-mode water retention curve and dual-mode unsaturated permeability on the variations of safety factor under rainfall loading. The results indicate that the safety factor variations of dual porosity soil slope modelled using the dual-mode water retention curve and the unsaturated permeability equation are lower than those of dual porosity slope modelled using single-mode water retention curve and unsaturated permeability equations.

• Journal of Climate Change Research
• /
• v.7 no.2
• /
• pp.193-203
• /
• 2016

The importance of forecasting agricultural production is receiving attention while climate change is accelerating. This study suggested three types of crop yield forecasting model for major vegetable crops by using downscaled meteorological information of main production area on farmland level, which identified as limitation from previous studies. First, this study conducted correlation analysis with seven types of farm level downscaled meteorological informations and reported crop yield of main production area. After, we selected three types of meteorological factors which showed the highest relation with each crop species and regions. Parameters were deducted from meterological factor with high correlation but crop species number was neglected. After, crop yield of each crops was estimated by using the three suggested types of models. Chinese cabbage showed high accuracy in overall, while the accuracy of daikon and onion was quiet revised by neglecting the outlier. Chili and garlic showed differences by region, but Kyungbuk chili and Chungnam, Kyungsang garlic appeared significant accuracy. We also selected key meteorological factor of each crops which has the highest relation with crop yield. If the factor had significant relation with the quantity, it explains better about the variations of key meteorological factor. This study will contribute to establishing the methodology of future studies by estimating the crop yield of different species by using farmland meterological information and relatively simplify multiple linear regression models.

• Journal of Environmental Science International
• /
• v.13 no.3
• /
• pp.233-244
• /
• 2004

This study was conducted to evaluate water quality in the Mankyung River using multivariate analysis. The analysis data which was surveyed from January 1996 to December 2002 in Mankyung river was aquired by the ministry of environment. Twelve water quality parameters were determined on each survey. The results were summarized as follow; Water quality in the Mankyung River could be explained up to 74.90% by four factors which were included in loading of organic matter and nutrients by the tributaries(43.28%), seasonal variation(10.40%), loading of pathogenic bacteria by domestic sewage of Gapcheon (12.41%) and internal metabolism in river(8.81%). The result of cluster analysis by station was classified into three group that has different water quality characteristics. Especially, Iksan river was appeared to considerable water quality characteristics against other station. In monthly cluster analysis, three group was classified by seasonal characteristics. Also, in yearly cluster analysis, three group was classified. It is necessary to control the pollutant loadings by domestic sewage and livestock waste for water quality management of Mankyung river.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.5
• /
• pp.131-144
• /
• 2020

The study investigates the impact of factors on environmental accounting implementation in mining enterprises in Binh Dinh province, Vietnam. The survey was carried out in three phases: 1) a draft survey form; 2) in-depth interviews with experts; 3) design questionnaire. The survey respondents were people who had knowledge of environmental information in mining enterprises in Binh Dinh province, including: accountant, chief accountant, financial deputy director or director. The questionnaire was is sent directly or through Google Form tool. The author received 162 responses votes from the survey respondent, out of which 13 were unusable due to missing data. Thus, 149 valid responses votes were used. This study employs Cronbach's alpha analysis, exploratory factor analysis and multivariate regression analysis. The results showed the influence of five different factors on environmental accounting implementation in mining enterprises in Binh Dinh province: stakeholders pressure, corporate characteristics, coercive pressure of government agencies, environmental awareness of senior managers and accountant qualifications of environmental accounting. While the pressure of stakeholders has a negligible influence, the remaining four factors (coercive pressure of government agencies, environmental awareness of senior executives, business characteristics, accountant qualifications of environmental accounting) have significant effect on environmental accounting implementation in mining enterprises in Binh Dinh province, Vietnam.

• Journal of Technologic Dentistry
• /
• v.39 no.4
• /
• pp.263-273
• /
• 2017

Purpose: This study aimed to explore the relations between class distracting factors and class satisfaction of the dental technology students and then provide a primary data to help further related studies and develop educational programs with which instructors can efficiently manage their classroom. Methods: For this study we have conducted a survey started from the beginning of May 2017 to the end of June. The subjects of the survey were Dental Technology students of D-city, K-city, W-city, selected by random sampling method. The questionnaire was self-administrated and 437 valid results were chosen for our analysis among 450 distributed questionnaires. Results: The results of the research was as follows. Firstly, The overall average point of class distracting factors was 2.5 point. The environmental factors were the highest point as 2.59 and as for the subcategories tiredness and drowsiness was the highest point as 2.76. Secondly, The overall average point of class satisfaction turned out 3,88 point and compliance with class and attitude factors gained the highest point as 4.06. Of the subcategories strict roll checking was the highest point as 4.17. Thirdly, As for class distracting factors from general characteristics a statistical significance was shown as follows; 'instructor factor'(p<.01), 'learner factor'(p<.05), 'total class distracting factor'(p<.05) in the area of gender, 'environmental factor'(p<.001), 'total class distracting factor'(p<.01), 'learner factor'(p<.05), 'instructor factor'(p<.05) in the area of gender 'learner factor'(p<.001), 'instructor factor'(p<.001), 'environmental factor'(p<.001), 'total class distracting factor'(p<.01) in the area of class grade, 'environmental factor'(p<.05) in GPA. Fourthly, A statistical significance, a negative correlation (p<.01) were shown between class distracting factors and class satisfaction. Class distracting factor that especially affects the class satisfaction was instructor factor(p<.001) and the explanatory power of the model turned out 14.7%, which was statistically meaningful (p<.001). Conclusion : Results of this study reveal that instructor factor is the key to class satisfaction of the students. So it is crucial that the instructor faithfully prepare for the class to reinforce the students' learning. Additionally further studies should be followed with more subjects and newer perspectives to develop innovative teaching methodology.

• Journal of the Korean housing association
• /
• v.10 no.1
• /
• pp.1-9
• /
• 1999

The subject of this study is housing environmental design of single family housing in urban, which intends to study the way of enhancing the quality of our housing environment through comparative research and analysis in Cheong-ju & Tama. The elements of the environmental design were reviewed for forming of street, open space and park, housing utilities, and environmental facilities. The results are as follows: 1. The plans require informally related influential factor. 2. To make street in housing area as not traffic facilities but a space residents life. 3. In order to improve housing environment, We have to design the elements efficiently for comfort of life.

• Journal of Korean Society on Water Environment
• /
• v.25 no.3
• /
• pp.411-418
• /
• 2009

The analysis of characteristics of water use evaluation and nighttime domestic flow evaluation was performed by using result from flow monitoring and surveying water supply records and nighttime domestic flow for a year. The analysis of correlations showed that, for both sites, the infiltration ratio and wastewater flow have shown a good relationship with high correlation factor and that the calculation of wastewater flow was highly affected by monthly rainfall depth as well as number of rain days. From this result, it was concluded that the measurement of infiltration should be performed when the rainfall does not significantly affect the sewer flow. Also, it is notable that each value of calculated using method for infiltration evaluation are not comparable to each other, but independent methods. In selecting of evaluation method for infiltration, therefore, a great emphasis should be imposed to the character of area and the seasonal factor in order to select optimal one. It is desirable way for evaluating infiltration and reduction ratio using result from an optimal method.

• Journal of Environmental Health Sciences
• /
• v.44 no.6
• /
• pp.563-571
• /
• 2018

Objectives: The purpose of this study was to investigate the environmental pollution caused by exposure to air pollution in Korea. Therefore, it is necessary to investigate environmental and health factors through big data. Methods: Among the environmental diseases, the data centered on "percentage per day in 2015 to 2018". Data of environmental diseases and concentrations of air pollution monitoring network were analyzed. Results: Lung cancer and bronchiolitis obliterans were correlated with 0.027 and 0.0158, respectively, in the contamination concentration of fine dust ($PM_{10}$). Ozone, COPD, allergic rhinitis, and bronchiolitis obliterans were correlated with 0.0022, 0.0028 and 0.0093, respectively. At the concentration of $SO_2$ and the diseases of asthma, atopic dermatitis, lung cancer and bronchiolitis obliterans were 0.0008, 0.0523, 0.0016 and 0.0126, respectively. Conclusions: We surveyed the trends of air pollution according to the characteristics of Seoul area in Korea and evaluated the perception of Korea and the world. As a result, respiratory lung disease is thought to be a major factor in exposure to environmental pollution.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.11a
• /
• pp.182-190
• /
• 2005

This paper proposes central monitoring system(PVCMS) based on a TCP/IP network for effective integrating management about photovoltaic systems. We don't gain confidence the result of production simulation, because the output of PV system have many various environmental change factor. So if we can obtain real operated data about each sites and system types to use PVCMS, we can define the environment change factor to compare with simulation data. And this paper try to access about total management and data analysis methods of renewable energy through results analysis to synthesize of the operation.