• Korean Journal of Agricultural Science
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• v.17 no.2
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• pp.102-114
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• 1990

This study was carried out to analyze the operation of the sluice gates by taking Sabkyo Reservoir as the model, and to examine the formulae of the design criteria for the Agricultural Land Improvement Project by hydraulic model experiments. The results were summarized as follows ; 1. According to the records of gate operation for 9 years, the mean height of the opened gates was 4.13 m, the mean number of operated gates were 4.04, the average annual number of operation were 67 times, the average annual operating time were 192.5 hours, and the average operating time were 2.88 hours. 2. The water supplied through Sabkyo Reservoir was 88.15 megatons per year, which was about 1.4 times the effective storage capacity. And the annual volume of pumping in May, which is the most water demanding season, was 29.56 megatons in average. 3. As the submerged orifice was transformed into the surface orifice, the suggested formulae for the orifice flow on the design criteria for the Agricultural Land Improvement Project showed a discontinuous line on the transition zone. It should be improved, because it is different from the real hydraulic phenomena. 4. The formulae for the orifice flow which are divided into the submerged and surface orifices are being used. However, these formulae could be substituted for the formular, $q=C{\cdot}W\sqrt{2gH_1}$, if the discharge coefficient considering the reservoir water level, the sea water level, and the gate opening height is used.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.101-104
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• 2016

Curvularia leaf blight of creeping bentgrass (Agrostis stolonifera) putting green by caused Curvularia trifolii was observed in Hapcheon, Korea. In July to September 2014, curvularia leaf blight developed on leaf blades of creeping bentgrass as small water-soaked lesions that subsequently turned into dark-colored, necrotic spots. The spots were expanded and became gray, grayish-brown, or light brown, circular to oblong lesions with purple to dark brown borders that often were surrounded by a yellow halo. The necrotic lesions coalesced, became irregular in shape and caused tip or complete blighting of the leaves. Blighted leaf blades appeared grayish-white to tan. The fungus was identified by morphological characters and 16S rDNA sequencing as C. trifolii. Conidia of the pathogen were short, with predominantly 3-septa, straight or often curved, with end cells frequently paler than intermediate cells. Size of the 3-septate conidia in culture are $26{\sim}28{\times}11{\sim}12{\mu}m$. Pathogenicity of the fungus was proved by artificial inoculation on the host. This is the first report of C. trifolii causing leaf blight on creeping bentgrass in Korea.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.467-474
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• 2010

Cheonggukjang is one of the traditional fermented soy-based foods in Korean diets. Studies in cell cultures, humans have revealed anti-hypertension, anti-stress, anticancer, antioxidant, immune enhancing effects. Angelica gigas, Rehmanniae radix, and Red ginseng are popular medicinal plants and widely used for oriental medicine. In this study a strategy had been developed to mobilize beneficial phenolics from Angelica gigas, Rehmanniae radix, and Red ginseng combined with fermented soy by Cheonggukjang fermentation for antioxidant and Type II diabetes management. The quality and functional characteristics of Chenggukjang fermented with Angelica gigas, Rehmanniae radix and Red ginseng. Cheonggukjang (CKJ), Angelica gigas Cheonggukjang (CKJ-DD), Rehmanniae radix Cheonggukjang (CKJ-RG), Angelica gigas and Rehmanniae radix Cheonggukjang (CKJ-DD+RG) and Red ginseng Cheonggukjang (CKJ-RED) were evaluated. The mobilized phenolic profile was evaluated for antioxidant activity and the potential to inhibit ${\alpha}$-amylase linked to hyperglycaemia. This research has important implications for the development of functional soy-based-fermented foods enriched with Angelica gigas, Rehmanniae radix and Red ginseng phenolics for oxidative stress - induced diabetic complications. Furthermore, Hunter's color values of 5 types cheonggukjang, lightness (L-values), redness (a-values) and yellowness (b-values) were evaluated. Free amino acid content of CKJ-RED (0.993 mg/gd. w.) showed higher than that of CKJ (0.205 mg/g-d.w.).

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.552-561
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• 2019

In korea, debris-flow disasters are induced by typhoon and localized torrential rainfall annually. These disasters are particularly severe in the Korean national park due to its geomorphological characteristics. This study was conducted to analyze the landslide characteristics and forest environmental factors of landslide areas located in rugged mountain range in the Korean national park (Mt. Seorak, Mt. Jiri, and Mt. Sobaek). Overall, landslides occurred at 474 sites. The average area of the landslide scar among these sites was 1,212 ㎡. The average landslide sediment was 1,389 ㎥, average landslide length was 75 m, and the average width was 12.9 m. The landslides frequently occurred in regions with igneous rock and coniferous forest. In addition, slope gradient degree (31°-40°), slope gradient direction (N), vertical slope (concave), cross slope (concave), altitude (401-800 m), position (middle), stream order (first order), forest type (mixed), parent rock (igneous), and soil depth (<46 cm). The relationship between landslide soil volume and environmental factors showed positive correlation. The variables of vertical slope (complex), altitude (<1,201 m), and soil depth (<46 cm) correlated significantly at 1 % level.

• Journal of Climate Change Research
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• v.9 no.4
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• pp.303-312
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• 2018

In Ethiopia, climate change and deforestation are major issues hindering sustainable development. Local Ethiopian communities commonly perceive an increase in temperature and a decrease in rainfall. Meteorological data shows that rainfall has declined in southern Ethiopia, and spring droughts have occurred more frequently during the last 10-15 years. The frequently occurring droughts have seriously affected the agriculture-dominated Ethiopian economy. Forests can play an important role in coping with climate change. However, deforestation is alarmingly high in Ethiopia, and this is attributed mainly to agricultural expansion and fuel wood extraction. Deforestation has led to a decrease in various benefits from forest ecosystem services, and increased ecological and environmental problems including loss of biodiversity. To resolve the issues effectively, it is crucial to enhance climate change resilience through reforestation and various international collaborations are urgently needed. To continue collaboration activities for resolving these issues, it is first necessary to address fundamental questions on the nature of collaboration: does collaboration aim for a support-benefit or a mutual benefit situation; dividing the workload or sharing the workload; an advanced technology or an appropriate technology; and short-term and intensive or long-term and extensive?. Potential collaboration activities were identified by sectors: in the governmental sector, advancing governmental structure and policy, enhancing international collaborations and negotiations, and capacity building for forest restoration and management; in the research and education sector, identifying and filling gaps in forestry and climate change education, capacity building for reforestation and climate change resilience research, and developing bioenergy and feed stocks; and in the business and industry sector, supporting conservation based forestry businesses and industries, while promoting collaboration with the research and education sectors. It is envisaged that international collaboration for enhancing climate change resilience through reforestation will provide a strong platform for resolving climate change and deforestation issues, and achieving sustainable development in Ethiopia.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.399-403
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• 2012

The management of heavy metals in soil is important for environmental-friendly agriculture and keeping an ecosystem healthy. In this study, we examined the concentrations of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn, and As) in 260 paddy soils sampled from Gyeongnam Province. The concentrations of the heavy metals were 0.143 mg $kg^{-1}$ (ranged 0.003-0.537) for Cd, 0.322 (0.002-0.986) mg $kg^{-1}$ for Cr, 25.41 (6.03-76.19) mg $kg^{-1}$ for Cu, 16.36 (2.63-32.94) mg $kg^{-1}$ for Ni, 18.67 (4.16-87.02) mg $kg^{-1}$ for Pb, 71.76 (22.99-153.58) mg $kg^{-1}$ for Zn, and 3.516 (0.002-19.481) mg $kg^{-1}$ for As, respectively. In addition, the concentration of Cd was highest in mountain foot-slope, Ni and As were highest in diluvial terrace, and Zn was highest in marine plains. Higher concentrations of Cd, Cu, and Zn were found in silty clay loam soils compared to silt loam, sandy loam, and loam soils.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.333-340
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• 1985

In this paper, we discuss the role of allocative efficiency and X-efficiency in determining resource allocation under the share tenency. Economic efficiency of resource allocation is related to land reform. Classical and neoclassical schools insist that land reform must be achieved for agricultural development by more efficient use of inputs. According to them, there is no incentive for tenants to use inputs until $MVP{\ell}=wage$ under the share tenancy. But "equal efficiency" school's conclusions are different. They conclude that there is no productivity differences between owner cultivation and share tenancy, owing to monopoly power of landlords and/or landlords's transaction costs. Considering X-efficiency, the share tenancy is not as efficient as the owner cultivation. On the other hand, the productivity differences may be reverse, in which landlords cultivate their lands by wage contracts. Land reform--reduction of land rent or redistribution of land--will be benefitable not only for agricultural development, but also for resource allocation in farm management.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.67-74
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• 2006

Korean entomopathogenic nematodes were introduced into cultural management of turfgrasses to enhance white grub control in golf courses for saving labour and expenses and contribution to giving safe playing and working places for golfers and superintendents by environmentally friendly control strategy. The turfgrass height influenced efficacy of entomopathogenic nematodes. Efficacy was higher at short turfgrass both in pot using Galleria mellonella larvae and in golf courses using 2nd instar of Exomala orientalis and Ectinohoplia rufipes as baits. Aeration increased the efficacy of entomopathogenic nematodes which were lower virulent. Pre-aeration was more effective than post-aeration. Exomala orientalis larval population was reduced 80.4 and 66.0% in the pre-aeration and post-aeration with entomopathogenic nematode, Steinernema carpocapsae Pocheon strain compared to 35.4% in the no aeration treatment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.294-297
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• 2015

Recently, big data analysis which is based on machine learning has been gained a lot of attentions in various fields. Especially, agriculture is considered as one promising field that machine learning algorithm can be efficiently utilized and accordingly, lots of works have been done so far. However, most of the researches are focusing on the forecast of weather or analysis of genome, and machine learning algorithm for livestock management, especially which uses individual data of livestocks, e.g., temperature and movement, are not properly investigated yet. In this work, we propose fast abnormal livestock detection algorithm based on machine learning, more specifically expectation maximization, such that livestock which has problem can be efficiently and promptly found. In our proposed scheme, livestocks are divided into two clusters using expectation maximization based on their bionic data and the abnormal livestock can be detected by comparing the size of two clusters. Especially, we divide the case in which single livestock has problem and the case in which livestocks have epidemic such that fast response is enabled when epidemic case. Moreover, our algorithm does not need statistical information.

• Journal of Mushroom
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• v.10 no.1
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• pp.15-20
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• 2012

Ventilation effects of bottles($1,100m{\ell}$) for culturing Flammulina velutipes on its mycelial growth and mushroom production were investigated. The degree of ventilation were controlled with hole positions, upper and under, and hole sizes in the bottle lids. The ventilation effects were measured with the contents of carbon dioxide, free sugars, chitin, moisture in the bottles and with the amount of produced mushrooms from the bottles. Carbon dioxide concentrations within the culturing bottles at exponential mycelial growth period vertex were relatively high in the bottles with lids without both a sponge and an aeration hole, and in those with a smaller hole. Free sugar contents in the mycelia were the highest in those with a 47mm hole on both sides, and in those with 26~33mm holes only underside. Chitin content was the highest in those with a 26mm hole only underside. On the other hand, the lids with 42mm~47mm holes on the both sides greatly lost water and decreased the mushroom production. In conclusion, the most efficient ventilation hole sizes on the lids for bottle($1,100m{\ell}$) cultivation of Flammulina velutipes using $1,100m{\ell}$ polypropylene bottle were 19mm on both sides of the lid and 26mm on only underside. They produced more mushrooms than the control by 6~9 %.