• Journal of Environmental Science International
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• v.27 no.7
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• pp.499-507
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• 2018

Agricultural meteorological information is an important resource that affects farmers' income, food security, and agricultural conditions. Thus, such data are used in various fields that are responsible for planning, enforcing, and evaluating agricultural policies. The meteorological information obtained from automatic weather observation systems operated by rural development agencies contains missing values owing to temporary mechanical or communication deficiencies. It is known that missing values lead to reduction in the reliability and validity of the model. In this study, the hierarchical Bayesian spatio-temporal model suggests replacements for missing values because the meteorological information includes spatio-temporal correlation. The prior distribution is very important in the Bayesian approach. However, we found a problem where the spatial decay parameter was not converged through the trace plot. A suitable spatial decay parameter, estimated on the bias of root-mean-square error (RMSE), which was determined to be the difference between the predicted and observed values. The latitude, longitude, and altitude were considered as covariates. The estimated spatial decay parameters were 0.041 and 0.039, for the spatio-temporal model with latitude and longitude and for latitude, longitude, and altitude, respectively. The posterior distributions were stable after the spatial decay parameter was fixed. root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and bias were calculated for model validation. Finally, the missing values were generated using the independent Gaussian process model.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.347-356
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• 2018

Genetically modified (GM) crops have been increased continuously over the world and concerns about the potential risks of GM crops have also been increasing. Even though GM crops have not been cultivated commercially in Korea, it should be necessary to develop the safety assesment technology for GM crops. In this study, we investigated the influence of heading date difference on gene flow from GM to non-GM rice. In the experimental plot design, The PAC GM rice was placed in the center as a pollen donor and non-GM rice were placed in eight directions as pollen receivers. Five pollen receiver rice cultivars were Unkawng, Daebo, Saegyejinmi, Nakdong-byeo, and Ilmi which had different flowering times. A total of 266,436, 300,237, 305,223, 273,373, and 290,759 seeds were collected from Unkawng, Daebo, Saegyejinmi, Nakdong, and Ilmi, respectively, which were planted around PAC GM rice. The GM${\times}$non-GM hybrids were detected by repeated spraying of herbicide and PAT immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using PAC gene specific primer. The hybrids were found in Nakdong-byeo which had the same heading date with PAC GM rice. The hybridization rate was 0.0007% at Nakdong-byeo plot. All of GM${\times}$non-GM hybrids were located within 2 m distance from the PAC GM rice zone. The physiological elements including rice heading date were found to be important factors to determine GM?rice out crossing rate with GM rice. Consideration should be taken into for many factors like the physiological elements of field heading date of rice cultivars to set up the safety management guideline for prevention of GM rice gene flow.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.110-126
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• 1995

Korean economy has been developed successfully in the course of implementing the five year economic development plans since 1962. The gap of incomes and quality of life between rural and urban area has been widened and it made rural farm laborers drain to urban areas. Therefore the prevailing situation of labor shortage and wage hike in rural area has made farm management deteriorate in recent years. Under the internal and international unfavorable economic conditions, marginal farm land of 66.5 thousand ha has been idled as of end of 1993. The total area outside agricultural development zone with bad farming conditions including irrigation and drainage, and land consolidation for mechanization were estimated at 360.4thousand ha equivalent to 17.5% of the total farm land area in Korea. Considering the topographical conditions of marginal lands, the effective use of marginal lands should be studied from the view point of public interest rather than from the view point of individual economic conditions. Considering the present agricultural economic settings, such as price decrease, unfavourable benefits of farm products, labour shrotage, free trade of farm products and poor physical condition of marginal lands, the institutional and realistical measures for the effective utilization of idle and marginal land should be studied as soon as possible. Detail land use pattern should be surveyed in the areas outside agricultural development zone and have to be classified as orchard farms, grass land, fish culture farms, lawn and ornamental tree farm, sight seeing and leisure farms for urban peoples, special crops production farms and common farms to be developed for farm mechanization. According to the surveyed results, the expected utilization patterns of the idle and marginal lands could be considerd as village common use, farm land base development, leisure farm development, mutual complementary utilization between urban and rural areas, G't purchase and management, credit supply and new extension services, improvement of cropping patterns and sight seeing and leisure farm patterns. For the successful and reasonable management of the marginal lands, the actions such as institutional improvement, prohibition of idle marginal land, enforcement of activities of farm management committee members and land banking system of RDC including development and utilization systems should be included.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.238-238
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• 2015

There are demands for water environmental analysis of discharge processes in paddy fields, however, it is not fully understood in nutrients discharge process for watershed modeling. As hydrological processes both surface and ground water and agricultural water managements are so complex in paddy fields, the development of lowland paddy fields watershed model is more difficult than upland watershed model. In this research, the improvement of SWAT (Soil and Water Assessment Tool) model for a paddy watershed was conducted. First, modification of surface inundated process was developed in improved pot hole option. Those modification was evaluated by monitoring data. Second, the monitoring data in river and drainage channel in lowland paddy fields from 2012 to 2014 were analyzed to understand discharge characteristics. As a case study, Imbanuma basin, Japan, was chosen as typical land and water use in Asian countries. In this basin, lowland paddy fields are irrigated from river water using small pumps that were located in distribution within the watershed. Daily hydrological fluctuation was too complex to estimate. Then, to understand surface and ground water discharge characteristics in irrigation (Apr-Aug) and non-irrigation (Sep-Mar) period, the water and material balance analysis was conducted. The analysis was composed two parts, watershed and river channel blocks. As results of model simulation, output was satisfactory in NSE, but uncertainty was large. It would be coming from discharge process in return water. The river water and ground water in paddy fields were exchanged each other in 5.7% and 10.8% to river discharge in irrigation and non-irrigation periods, respectively. Through this exchange, nutrient loads were exchanged between river and paddy fields components. It suggested that discharge from paddy fields was not only responded to rainfall but dynamically related with river water table. In general, hydrological models is assumed that a discharge process is one way from watershed to river. However, in lowland paddy fields, discharge process is dynamically changed. This function of paddy fields showed that flood was mitigated and temporally held as storage in ground water. Then, it showed that water quality was changed in mitigated function in the water exchange process in lowland paddy fields. In future, it was expected that hydrological models for lowland paddy fields would be developed with this mitigation function.

• Korean Journal of Agricultural Science
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• v.44 no.2
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• pp.221-227
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• 2017

This study is the evaluation of the 'Tunak forest recreation and ecotourism development project' which will be completed in 2018 with sole source of funding from Korea. A survey was conducted to evaluate the status of the project being carried out in Lombok island, Indonesia, through the evaluation principles and criteria of the OECD Development Assistance Committee (DAC). Survey participants were stakeholders of the Official Development Assistance (ODA) project and local residents. Overall, the respondents had a good impression of this ODA project and expected they would contribute to the development of their community and region. However, respondents were not well aware of the ODA project being carried out in the Tunak region and thus more efforts should be made to help the local residents understand the positive outcome of the project and to promote the ongoing cooperation between Korea and Indonesia in the forestry sector. Results of this study showed that the projects have been effectively carried out and the impact of the project was well perceived by the recipient country. In addition, this positive perception of Korea is expected to help recreation and ecotourism business progress in the region. Therefore, we believe that the project should continue to be carried-out in the future and we expect that related companies will be able to operate on its own eventually. As it is difficult to evaluate the outcome of an ongoing project precisely, this study should be conducted again after the project completion and the results can be compared to the present results so that the effectiveness of ODA project can be more accurately determined.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.1
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• pp.14-21
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• 2017

Gastric ulcer is a clinical symptom characterized by inflammation of the gastric mucosa. Stress and alcohol consumption have been identified as the major cause of gastric ulcer. However, the effects of silkworms on ethanol-induced gastric ulcer have not been studied yet. The mature silkworms that are difficult to eat have become easier to ingest due to recent technological development to make steaming and freeze-drying mature silkworm larval powder (SMSP). In this study, we investigated whether three silkworm varieties, Baekokjam, Golden-silk and Yeonnokjam could alleviate ethanol-induced gastric mucosal damage in vivo. Sprague-Dawley rats pretreated with 3 SMSPs (0.1 or 1 g/kg BW) or normal diet (AIN-76A) were exposed to absolute ethanol (3 g/kg BW, 3 h) by oral gavage. Morphological examination included ulcer index as a measurement of hemorrhages and hematoxylin and eosin staining was performed to analyze the severity of gastric ulcer. Results of macroscopic examination suggested that all 3 SMSPs pretreatment significantly protected gastric mucosa against ethanol-induced damage. Microscopic observations demonstrated significant mucosal erosion and inflammation in ethanol-treated rats, which was abrogated in rats pretreated with 3 SMSPs. In addition, pretreatment with all 3 SMSPs showed significant decreases the expression of pro-inflammatory mediators, IL-6 and cyclooxygenase-2. Among SMSP from 3 varieties of silkworm, preadministration of 1 g/kg Baekokjam SMSP showed the most effective protective effect against ethanol-induced gastric ulcer. These results suggest that Baekokjam SMSP can be a potential gastroprotective agent against ethanol-induced gastric ulcer.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.1
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• pp.22-29
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• 2017

Increased alcohol consumption is a burden on the world because it is associated with various health problems. However, the effects of silkworms on alcohol metabolism have not been studied yet. The hard-to-eat mature silkworms have become easier to ingest recently due to the development of technology, steam-lyophilising mature silkworm larvae. In this study, we investigated and compared the effects of SMSPs from three silkworm varieties, Baekokjam, Golden-silk and Yeonnokjam weaving white, golden, and light green cocoons on alcohol metabolism in vivo. Sprague-Dawley rats pretreated with three SMSPs (0.1 g/kg or 1 g/kg body weight) or normal diet (AIN-76A) for 2 weeks were subjected to intragastric administration of absolute ethanol (3 g/kg body weight, 3 h). Three SMSPs did not affect the final body weight and liver weight. All 3 SMSPs were effective to reduce the enzymes in alcohol metabolism, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), and liver damage and enzymes involved in liver damage, aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Among SMSP from 3 varieties of silkworm, preadministration of 1 g/kg Baekokjam SMSP showed the most effective suppressive effect on the activities of ADH, ALDH, AST and ALT. The Baekokjam SMSP contained higher amounts of beneficial amino acids than Golden-silk or Yeonnokjam SMSP. These results suggest that Baekokjam SMSP might be used as a new and promising candidate for improving alcohol metabolism and liver injury through promoting rapid alcohol metabolism.

• Journal of Agricultural Extension & Community Development
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• v.21 no.3
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• pp.181-213
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• 2014

This study analyzes the approach method for the excavation of the outstanding projects in order to improve the ODA quality in the agricultural sector in a situation of the recent quantitative expansion of the Korea's ODA. This analysis is based on the ODA development paradigm of the international society, Korea's ODA development trends, the problems of system, procedure and contents. The analysis drew five approaches, such as an approach based on the strategies, an approach based on the comparative advantage, an approach based on the partnership, an approach based on the networking, an approach of modeling. If each approach method is applied to the excavation of project closely linked to other approach methods, it would be easier to excavate outstanding project. And it could lead to enhancement of project effectiveness. This study introduced the KAPEX program which excavate the customized ODA projects through the application of these approach methods.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.2
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• pp.51-57
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• 2014

Bumblebees are important pollinators of crops and wildflowers. The Korean native bumblebee, Bombus ignitus, undergoes one generation per year, and induction of artificial hibernation is essential for year-round rearing of the bumblebee. Keeping queens under cold treatment conditions for several mo is an effective method for terminating their diapause and promoting colony development. In the present study, we investigated how the timing and duration of chilling affect the artificial hibernation of B. ignitus queens. In the timing assessment, cold treatment was instituted at 12 d, 40 d, or 100 d after eclosion under a constant temperature of $5^{\circ}C$ and 80% humidity. The queens that entered cold treatment at 12 d after emergence evidenced the highest survival rates: 86.7% at two mo, 73.3% at three mo, and 46.4% at 4 mo. Survival rates were reduced under storage conditions at 12 d, 40 d, and 100 d after emergence. When queens were subjected to chilling at 8 d, 12 d, or 16 d after eclosion with constant 80% humidity, the queens stored at 12 d after eclosion exhibited the highest survival rates, which were 84.6 at one mo, 25.0% at two mo, and 7.9% at three mo. In regards to the duration of the cold period, the queens that hibernated for at least two mo evidenced optimal colony development rates. The rates of oviposition, colony foundation, and progeny-queen production of queens hibernated for two mo were 60.0%, 30.0%, and 13.3%, respectively. These values were 6.0 to 13.3 times higher than those in the queens that hibernated for 15 d. Therefore, a cold period of at least 2 mo applied 12 d after emergence were found to be the most favorable conditions for diapause break in B. ignitus queens.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.183-204
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• 2015

Papua New Guinea, birthplace of the South Pacific, is a natural nation which have potential of increasing crops output because it has optimum condition for crop growth as tropical rain forest climate under hot and humid climate. Farming village of Papua New Guinea want to produce crops for create income beyond the self-sufficiency. It needs the technological transfer such as irrigation facilities and understanding of agricultural weather condition for good crops production. In particular, it needs a improvement through pH, EC, ORP for make optimum soil condition and it need the standardization production and farm products what the consumer wants. Internationally technical cooperation is needed for agricultural development of Papua New Guinea and maintenance of international cooperation will help for economic development between the two countries. In particular, basic environment research for agricultural development of Papua New Guinea is expected to play a larger role of technical cooperation of agriculture.