• Korean Journal of Medicinal Crop Science
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• v.20 no.2
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• pp.85-88
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• 2012

This study evaluated the germination rate of $Rheum$ $palmatum$ L. in Korea as affected by storage temperature, germination temperature, and a soaking treatment. The germination rate of $R.$ $palmatum$ L. stored at various conditions for 8 weeks was > 60%. The highest germination rate occurred at $25^{\circ}C$. The germination point of $R.$ $palmatum$ L. with soaking was started 1 day after application, and non soaked seeds germinated in 2 days. When $R.$ $palmatum$ L. was soaked with water, the germination rate was lower, but mean germination velocity was the highest. These results may help our understanding of variations in germination characteristics for seeds treated under different germination conditions.

• Hwankyungkyoyuk
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• v.23 no.4
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• pp.44-55
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• 2010

The purpose of this study is to develop an environmental report for children and to examine the learning effects of the environmental report on elementary school students. This study is carried out by the survey. The results of this study are as follows. First, the Environmental Report for children, which consists of 8 subjects related to the environmental policy in Korea. 1) Green Growth and Sustainable Policy, 2) Climate Change, 3) Water Supply and Sewage Policy, 4) Sustainable Watershed Management, 5) Conservation of Biodiversity, 6) Resource Recirculation, 7) Environmental Health for Children, and 8) Environmental Dictionary, was systematically developed. Second, the Environmental report developed was examined the effects to third and fourth grade elementary school students in Incheon and Daegu. By dividing elementary school students into two groups: A Control group and an Experimental group, the lessons were respectively executed. In conclusion, the Environmental Report leads to good effects when it is applied to both Environmental Education and the public relation of the Environmental Policy in Korea. Finally, it would be expected to be efficient in learning Sustainable Development and the Environmental Policy.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.3
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• pp.267-275
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• 2007

Nowadays, it grows bigger the importance of water resource management, and so, hydrographic surveying technology in river is important because it serves basic data about river environment. And, also, the application field of GPS has been increased and expected to be more increased because of the change of the geodetic reference system to World Geodetic System. In this study, hydrographic surveying in Hwang river in Geochang is accomplished by RTK GPS and Total Station and they are compared and analyzed the both results. The section profile in river is made by Hec-Ras program and CAD. The results show it can be saved 15.3% in surveying times and the amount of surveying works can be enlarged 42.5%. And the standard error between RTK results with calibration and the results without calibration turned out as 2.1 cm. So we have a conclusion that RTK GPS is more efficient surveying method than total station in hydrographic surveying in river.

• Journal of Korean Society of Rural Planning
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• v.18 no.3
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• pp.103-110
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• 2012

This study aims to find out the geographical distribution, the physical structure and characteristic of Gudle-jang Paddy-field in Cheongsando. On the basis of this study, the potential value and the assignment for the preservation of Gudle-jang Paddy-field were suggested. Gudle-jang Paddy-field is centrally distributed to Cheongsando and has various features as follows. First, it has the Ondol structure which is used Gudle-jang. Second, it has an irrigation canal which has functions of the tank and the prevention of cold-weather damage as well as the irrigation and drainage canal. The values of Gudle-jang Paddy-field are as follows; 1) It is the peculiar and inherent agricultural structure which is only found in Cheongsando. 2) It is the structure that the agricultural civil engineering and the agricultural water management technique of traditional methode are applied. 3) It has the worths of the traditional culture of Korea. 4) It is the important resource creating superb rural landscape of the region. In spite of these values of Gudle-jang Paddy-field, there were little efforts to preserve it. From now on, it is needed to form of sympathy about the value of Gudle-jang Paddy-field and to make efforts for preservation of it. Also the institutional and political strategy should be provided to preserve and manage Gudle-jang Paddy-field.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.137-149
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• 2019

Accurate estimation of reference evapotranspiration (RET) is important to quantify crop evapotranspiration for sustainable water resource management in hydrological, agricultural, and environmental fields. It is estimated by different methods from direct measurements with lysimeters, or by many empirical equations suggested by numerous modeling using local climatic variables. The potential to use some such equations depends on the availability of the necessary meteorological parameters for calculating the RET in specific climatic conditions. The objective of this study was to determine the proper RET equations using limited climatic data and to analyze the temporal and spatial trends of the RET in South Korea. We evaluated the FAO-56 Penman-Monteith equation (FAO-56 PM) by comparing several simple RET equations and observed small fan evaporation. In this study, the modified Penman equation, Hargreaves equation, and FAO Penman-Monteith equation with missing solar radiation (PM-Rs) data were tested to estimate the RET. Nine weather stations were considered with limited climatic data across South Korea from 1973 - 2017, and the RET equations were calculated for each weather station as well as the analysis of the mean error (ME), mean absolute error (MAE), and root mean square error (RMSE). The FAO-56 PM recommended by the Food Agriculture Organization (FAO) showed good performance even though missing solar radiation, relative humidity, and wind speed data and could still be adapted to the limited data conditions. As a result, the RET was increased, and the evapotranspiration rate was increased more in coastal areas than inland.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.23-29
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• 2022

The frequency of localized heavy rain is increasing due to the influence of abnormal climate that is rapidly increasing in recent years. As a result, the difficulty of safe water resource management is increasing and human and material damage is increasing. Various countermeasures are being established to reduce the damage caused by localized heavy rain, but small-scale mountain catchments are experiencing many difficulties due to the lack of a basic plan. Therefore in this study the risk of flooding was evaluated using the rainfall-runoff model in the Yu-pyeong catchment national park among national parks in Korea. As a result of the analysis, it was simulated that flooding occurred in the Yu-pyeong catchment of Mt. Jirisan when rainfall with a recurrence frequency of 50 years or more occurred, and it was confirmed that there was a high risk of structures, safety facilities and trails.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.4
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• pp.51-56
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• 2022

Purpose: By applying an ultrasonic mechanical device to the liquid fertilizer storage in the pig dropping treatment plant, the initial odor of the odor source is reduced, and the air dilution drainage of the complex odor is fundamentally recognized to facilitate odor treatment on the mechanical and chemical biological treatment devices at the rear. Research design, data and methodology: The odor concentration on the site boundary was measured to confirm the state of reduction. In order to prevent the spread of odor from the collection of the pig dropping treatment plant, it was measured by installing an ultrasonic generator inside the installation wall after installing the sealing wall. Results: The average value of the March and April measurement data remained close to neutral at 8.2 after 8.6 treatment before pH treatment, decreased 97.3% from 462 mg/L before SS treatment to 10.5 mg/L after treatment, and the composite odor was reduced by 85% from 20 to 3 before treatment. It was confirmed that ammonia (NH3) was reduced by 99% from 5.8 ppm to 0.09 ppm, and general bacteria were also reduced by 99% from 3,200 CFU/mL to 57 CFU/mL Conclusion: Applying the ultrasonic air ejector hybrid system and zigzag air complex module development product to resource circulation centers or sewage treatment facilities is thought to reduce inconvenience to residents due to odors caused.

• Fisheries and Aquatic Sciences
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• v.27 no.7
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• pp.421-433
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• 2024

Among larger species of fish found in Punatsang chhu, Brown trout (Salmo trutta) and Snow trout (Schizothorax richardsonii) are notable species. Snow trout is a native species, whereas Brown trout is an introduced species. Brown trout is noted to have a negative impact on the population of native species worldwide. This study studied the population dynamics and structure of these species to detect if the introduced species affected the native species adversely. The study was conducted on a 30 km stretch of Punatsang chhu including its major and minor tributaries at about their confluences. In total, 56 sample plots of a 200 m sampling stretch were studied with a 200 m distance between each stretch. Length, weight, maturity, and sex data for both species were collected along with the habitat and water parameters. The two species were found to prefer different areas within a single stretch with a rare overlap. Snow trout were found to be distributed widely within the basin whereas Brown trout were only found in altitudes higher than 1,000 masl ($\overline{x}$ = 1,231.77) and in turbid waters (p = 0.009). Recruitment of Snow trout was not good whereas recruitment of Brown trout was good. Length-frequency graphs indicated good inverse J distribution for the Snow trout population and sporadic for Brown trout. There is an effect of Brown trout introduction to the Snow trout living in the study area. Places invaded by Brown trout have a lesser presence of Snow trout compared to places not invaded by these species.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.720-734
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• 2023

To understand the spatiotemporal distribution pattern of zooplankton and the environmental factors influencing zooplankton abundance in Gomso Bay, major harvesting area of Manila clam (Venerupis philippinarum) in South Korea, zooplankton sampling was conducted four times in autumn (October 2022), winter (January 2023), early spring (March 2023), and spring (May 2023). Among the environmental factors of Gomso Bay, water temperature, chlorophyll a concentration (Chl-a), dissolved oxygen (DO), and pH observed different patterns, while salinity and suspended particulate matter(SPM) showed no significant statistical differences between the survey periods. The zooplankton in Gomso Bay occurred 33, 29, 27, and 29 taxonomic groups during each respective survey period. In October 2022 and May 2023, arthropod plankton were dominated, while in January and March 2023, protozoa were primarily dominant. Among the Arthropods, copepods including Acartia hongi, Paracalanus parvus s. l., Corycaeus spp., and Oithona spp. commonly found along Korean coastal areas of the Yellow Sea, were dominated. Cluster analysis based on zooplankton abundance indicated a single community (stable condition) in each season, attributed to low dissimilarity distances, while three distinct clusters (autumn, winter-early spring, spring) between seasons indicated a highly seasonal environment in Gomso Bay.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.6
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• pp.422-429
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• 2013

It is generally known that the increase of the Earth surface temperature due to the global warming together with the land desertification by rapid urban development has caused severe climate and weather change. In desert or desertification land, it is observed that there are always severe flooding phenomena, even if desert sand has the high porosity, which could be believed as the favorable condition of rain water infiltration into ground water. The high runoff feature causes possibly another heavy rain by quick evaporation with the depletion of underground water due to the lack of infiltration. The basic physics of desert flooding is reasonably assumed due to the thermal buoyancy of the higher temperature of the soil temperature than that of the rain drop. Considering the importance of this topic associated with water resource management and climate disaster prevention, no systematic investigation has, however, been reported in literature. In this study, therefore, a laboratory scale experiment together with the effort of numerical calculation have been performed to evaluate quantitatively the basic hypothesis of run-off mechanism caused by the increase of soil temperature. To this end, first, of all, a series of experiment has been made repeatedly with the change of soil temperature with well-sorted coarse sand having porosity of 35% and particle diameter, 2.0 mm. In specific, in case 1, the ground surface temperature was kept at $15^{\circ}C$, while in case 2 that was high enough at $70^{\circ}C$. The temperature of $70^{\circ}C$ was tested as this try since the informal measured surface temperature of black sand in California's Coachella Valley up to at 191 deg. $^{\circ}F$ ($88^{\circ}C$). Based on the experimental study, it is observed that the amount of runoff at $70^{\circ}C$ was higher more than 5% compared to that at $15^{\circ}C$. Further, the relative amount of infiltration by the decrease of the surface temperature from 70 to $15^{\circ}C$ is about more than 30%. The result of numerical calculation performed was well agreed with the experimental data, that is, the increase of runoff in calculation as 4.6%. Doing this successfully, a basic but important research could be made in the near future for the more complex and advanced topic for this topic.