• Journal of Environmental Science International
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• v.17 no.7
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• pp.817-826
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• 2008

Using high voltage electric fields induced by high voltage AC (10-12 kV/cm, 20 kHz) and pulsed (20-30 kV/cm, 40 Hz) electric field generator as a semipermanent and environment-friendly disinfecting apparatus, the disinfection effect of coliform group in the effluent of sewage plant was investigated. The effects of electric field strength, treatment time, discharge area of a discharge tube, water quality factors (electric conductivity, pH and SS) on its death rate were examined. The death rate of coliform group was increased with increasing electric field strength and treatment time. For AC and pulsed electric field generator, the critical electric field strength was 6 kV/cm and 2 kV/cm, respectively, and the critical treatment time was 5 min and 2 min, respectively, regardless of electric field strength. Comparing the death rate of coliform group by AC and pulsed electric fields used in this study, its death rate was higher for the latter than the former, but did not increase linearly with increasing electric field strength. The results obtained for the effects of discharge area, electric conductivity, pH and SS on the death rate of coliform group using AC electric field (12 kV/cm, 20 kHz) were as follows: its death rate showed the trend to increase linearly with increasing discharge area; for the effect of electric conductivity, its death rate was increased with increasing electric conductivity, regardless of ionic species, increased with increasing cationic valency, but was similar between the same cationic valency; the pH $5{\sim}9$ used in this study did not affect its death rate; its death rate was decreased with increasing SS concentration.

• Journal of Environmental Health Sciences
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• v.33 no.6
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• pp.502-505
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• 2007

To estimate the soil quality of Miryang area, soil analysis were conducted according to the city and out of city of soil expenses at according to analysis components and heavy metal pollution of irradiation sampling sites. The through soil components the principal element about the 71% $SiO_2\;and\;Al_2O_3$, the pH of field area near the city center was lower than that of the other field area, which indicated that this acidification was probably attributed to the acid rain caused by the traffic exhaust gas such as $SO_x\;and\;NO_x$. Acidification was more severe in the field area than in the farming land. The concentration of five heavy metals such as Cu, Cd, Pb, As and Cr were found to be lower than the standard of soil pollution. An assessment using the SPI(Soil Pollution Index), which was developed to estimate an overall soil quality, was performed. Each SPS(Soil Pollution Score) were evaluated with the results of the data from this study. The soil quality of most area of Miryang land was determined to Class 1, which indicated that the soil was healthy.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.277-284
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• 2023

Since the radiological risk is different depending on the working environment, protection measures and policies must be developed through analysis of the field area environment. Evaluating the characteristics of the field area that uses radiation should be conducted through comparative analysis with other industries, not just the numerical value of the field area. In this study, evaluation factors were derived from exposure records by the department to compare radiation occupational exposure records by sector. And then, we developed a polygonal model for comparative analysis and applied them to eight work fields through ten evaluation factors. Based on the occupational exposure record in 2020, a polygonal model was applied to compare and evaluate the characteristics of the radiation work area. Through this, the usefulness of the polygonal model was confirmed, and protection policy measures for the industry were proposed.

• Korean Journal of Remote Sensing
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• v.16 no.2
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• pp.109-116
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• 2000

This study was carried out to assess the use of RADARSAT data which is C-band with HH polarization for the rice growth monitoring in Korea. Nine time-series data were taken by shallow incidence angle (standard beam mode 5 or 6) during rice growing season. And then, backscattering coefficients ($\sigma$$^{\circ}$) were extracted by calibration process for comparing with rice growth parameters such as plant height, leaf area index(LAI), and fresh and dry biomass. Field experimental data concerned with rice growth were collected 8 times for the ground truth at the study area, Tangjin, Chungnam, Korea. At the beginning of rice growth, backscattering coefficients were ranged from -l6~-l3dB when rice fields were not covered with rice canopy and flooded. At the maximum vegetative stage of rice, backscattering coefficients of the rice field were the highest ranging from -4.4dB~-3.1dB. The temporal variation of backscattering coefficient($\sigma$$^{\circ}$) in rice field was significant in this study. Backscattering coefficient ($\sigma$$^{\circ}$) of rice field was a little bit lower again after heading stage than before. This results show RADARSAT data is promising for rice monitoring.

• Journal of Korean Society of Rural Planning
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• v.21 no.3
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• pp.131-144
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• 2015

With a view to creating beautiful farm villages, this study aims to exploit space syntax and thereby establish a systematic plan for refurbishing common farming facilities in farm villages by expanding a remodeling plan that has so far been focused on farm houses to cover different villages as well as in spatial scope. For this purpose, the study has extracted a system of categories for common ownership facilities in farm villages and applicable elements needed for collaboration in the space of joint production by performing a comprehensive analysis of related literature for the purpose of researching the distribution of common farming facilities. Based on such categorization of applicable elements, the study conducted a field survey of the four types of farm villages such as suburban area (Hwaseong), inland farming-centered area (Jeungpyeong), coastal & plain area (Goheung), and mid-mountain area (Gangneung), through group discussions by participating researchers and field pilot surveys. Also, space analysis has come up with measurements based on the five criteria of integration, local integration, control, connectivity, and spatial depth. And a plan for type-specific remodelling of common farming facilities has been drawn up through standardization based on the values in integration for different villages and spatial depth for common farming facilities. The significance of the current study consists in identifying how the location of common farming facilities influences the characteristics of different villages in terms of spatial structure and then drawing up guidelines for planning their placement.

• Journal of the Korean housing association
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• v.23 no.1
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• pp.89-96
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• 2012

The purpose of this study is to find out the characteristics of activity areas according to the age difference and provide the alternatives for space planning of activity areas in classroom of childcare centers. This study used the content analysis method for field survey data collected from 36 classrooms of 9 childcare centers in the Daejeon area. Floor plans were converted to Autocad drawings to analyze the characteristics of activity areas. The results of this study were as follows; 1) In case of 0 to 2-year-old classrooms, they had 6 activity areas such as gross-motor area, role play, block building, language, creative expression, exploration/manipulation area. The activity area with the most low frequency was gross-motor area. 2) In case of 0 to 2-year-old classrooms, the size of activity area was in order of gross-motor area > role play > block building > language > creative expression > exploration/manipulation area. In case of 3 to 5-year-old classrooms, the size of activity area was in order of language > art > role play > math > block building > science > tone and rhythmic area. 3) The central areas with easy access in 0 to 2-year-old classrooms were Large-motor and Imaginary Play Areas. Also, more isolated areas were Manupulatives and Block Areas. The central areas with easy access in 3 to 5-year-old classrooms were Arts, Numbers and Manupulatives. While more isolated areas were Music, Movement and Science Areas.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.520-529
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• 2017

In Korea, the largest agricultural lands are paddy fields which have poor infiltration and drainage properties. Recently, Korean government pursuits cultivating upland crops in paddy fields to reduce overproduced rice in Korea. In order to succeed this policy, it is critical to set criteria suitability classification for upland crops cultivating in paddy field soils. The objective of this study was developing guideline of suitability classification for sesame cultivation in paddy field soils. Yields of sesame cultivated in paddy field soils and soil properties were investigated at 40 locations at nationwide scale. Soil properties such as topography, soil texture, soil moisture contents, slope, and drainage level were investigated. The guideline of suitability classification for sesame was determined by multi-regression method. As a result, sesame yields had the greatest correlation with topography, soil moisture content, and slope. Since sesame is sensitive to excessive soil moisture content, paddy fields with well drained, slope of 7-15% and mountain foot or hill were best suit for cultivating sesame. Sesame yields were greater with less soil moisture contents. Based on these results, area of best suitable paddy field land for sesame was 161,400 ha, suitable land was 62,600 ha, possible land was 331,600 ha, and low productive land was 1,075,500 ha. Compared to existing suitability classification, the new guideline of classification recommended smaller area of best or suitable areas to cultivate sesame. This result may suggest that sesame cultivation in paddy field can be very susceptible to soil moisture contents.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.414-426
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• 2004

This study analysed inquiry process and activities of the inquiry area in the chemistry field of middle school science textbooks by the inquiry elements based on the 7th science curriculum. The purpose of this study is to grasp a degree of reflecting the 7th science curriculum in the 9th grade science textbooks, and to find out educational implications for the various inquiry learning. Overall, for the analysis of inquiry elements, basic inquiry elements except classification were well reflected on the middle school science textbooks in 9th grade. However, for the integrated inquiry elements, interpreting data occupies almost half of them. This phenomenon is shown in the analysis of inquiry process and inquiry activities, as well. Especially, project and field trip introduced in the 7th science curriculum are hardly found in the textbooks. 9th grade is classified as an upper grade in the 7th science curriculum in terms of inquiry level. Integrated inquiry elements and inquiry activity types, however, are not thoroughly reflected in the 9th grade science textbooks. It is desirable that a variety of inquiry learning of 9th grade be implemented by reconstructing inquiry area based on the results of this study. Hence the degree and ratio of utilizing the integrated inquiry elements and inquiry activity types to the inquiry area of science textbook in 9th grade should be studied.

• Ocean and Polar Research
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• v.24 no.3
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• pp.197-205
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• 2002

Total magnetic field and high-resolution bathymetric data were collected over nine seamounts to the northwest of the Marshall Islands in the western Pacific. Magnetic parameters including inclination and declination were calculated from the magnetic anomalies using inversion algorithm of Plouff (1976), and a corresponding paleomagnetic pole was determined with the magnetic parameters. The paleomagnetic poles determined in this study were compared with the previous apparent polar wander path (APWP) of Pacific plate. Most seamounts of the study area have normal polarity. The study reveals that all nine seamounts in the study area formed in the southern hemisphere during the Cretaceous based on their comparison with the APWP of Pacific plate. The ages estimated from paleomagnetic poles can be divided by age into three groups: the oldest (OSM1 and OSM3), middle age (OSM2, OSM4, and 6-2), and the youngest (OSM5-1, 5-2, 5-3, and 6-1). The fermer two groups and the latter seem to be coincident with two distinct pulses of Cretaceous volcanic activity (115-90 Ma and 83-65 Ma). As a whole the seamounts at southwest of the study area are older than at those northeast.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.5
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• pp.87-95
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• 2010

The optimum volume of sediment settling pond is determined by the maximum rainfall and surface peak rate runoff from crop field. Based on analysis of measured rainfall and runoff data, it was found that rainfall intensity of 2 mm/min would result in peak rate runoff from the agricultural field of study area. Optimum pond volume under various slope scenarios were determined using the WEPP model calibrated with measured flow and sediment data for the study watershed. For the agricultural field with the slope of 7 % and area of $2,600\;m^2$ at the study area, at least $6.4\;m^3$ of sediment settling pond is needed as shown in this study. The results presented in this study could be used as a guide in designing appropriate volume of sediment settling pond at highland agricultural areas because both very detailed field measurement and calibrated WEPP model results are used in the analysis.