• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.130-130
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• 2003

Gummy stem blight pathogen is very difficult not only to monitor the inoculum levels prior to host infection, and also it is destructive and hard to control in field condition. We have applied RAPD technique to elucidate the genetic diversity of the genomic DNA of Didymella bryoniae and also to generate specific diagnostic DNA probe useful for identification and detection. The 40 primers produced clear bands consistently from the genomic DNA of twenty isolates of Didymella bryoniae, and two hundred seventy-three amplified fragments were produced with 40 primers. The combined data from 273 bands was analyzed by a cluster analysis using UPGMA method with an arithmetic average program of NTSYS-PC (Version 1.80) to generate a dendrogram. At the distance level of 0.7, two major RAPD groups were differentiated among 20 strains. RAPD group (RG) I included 8 isolates from watermelon except one isolate from melon. RAPD group (RG) IV included 12 isolates from squash, cucumber, watermelon and melon.. In amplification experiment with SCAR specific primer RG1F-RG1R resulted in a single band of 650bp fragment only for 8 isolates out of 20 isolates that should be designated as RAPD Group 1. However, same set of experiment done with RGIIF-RGIIR did not result in any amplified product.. Our attempts to detect intraspecific diversity of ITS region of rDNA by amplifying ITS region and 17s rDNA region for 20 isolates and restriction digestion of amplified fragment with 12 enzymes did not reveal polymorphic band. In order to develop RAPD markers for RGIV specific primer, a candidate PCR fragment( ≒1.4kb) was purified and Southern hybridized to the amplified fragment RGIV isolates. This promising candidate probe recognized only RGIV isolates

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.619-627
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• 2022

In Korea, apples and pears are among the most important agricultural products to farmers who seek to earn money as income. Generally, farmers make decisions at various stages to maximize their income but they do not always know exactly which option will be the best one. Many previous studies were conducted to solve this problem by predicting farmers' income structure, but researchers are still exploring better approaches. Currently, machine learning technology is gaining attention as one of the new approaches for farmers' income prediction. The machine learning technique is a methodology using an algorithm that can learn independently through data. As the level of computer science develops, the performance of machine learning techniques is also improving. The purpose of this study is to predict the income structure of apples and pears using the automatic machine learning solution H2O.AI and to present some implications for apple and pear farmers. The automatic machine learning solution H2O.AI can save time and effort compared to the conventional machine learning techniques such as scikit-learn, because it works automatically to find the best solution. As a result of this research, the following findings are obtained. First, apple farmers should increase their gross income to maximize their income, instead of reducing the cost of growing apples. In particular, apple farmers mainly have to increase production in order to obtain more gross income. As a second-best option, apple farmers should decrease labor and other costs. Second, pear farmers also should increase their gross income to maximize their income but they have to increase the price of pears rather than increasing the production of pears. As a second-best option, pear farmers can decrease labor and other costs.

• Journal of Mushroom
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• v.17 no.1
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• pp.1-6
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• 2019

Agrocybe cylindracea was cultured in a bag, in which sawdust culture medium (1 kg) is put in a plastic bag (PE), with poplar sawdust, rice bran, wheat bran, and dried bean curd refuse in the ratio of 70:10:10:10 (v/v). 2% of the culture medium was inoculated with the liquid starter of Agrocybe cylindracea, and this was incubated at $25^{\circ}C$. After incubation, the A. cylindracea was further cultured by cutting the top vinyl portion of the bag down to the level of the culture medium surface of the first inoculation part. The cut culture medium was placed in a growth room at $25^{\circ}C$, and pin-heading was induced under light irradiation at 99% humidity and 1,000 ppm $CO_$ level for 3days. When the grow the environment was controlled at 95% humidity and $21^{\circ}C$, the bending of the stem was less as compared to that when the cap of the bag had been removed. The number of effective fruiting bodies per bag increased by 140% (28.8), the quantity per bag increased by 29.5%, and 148.5 g A. cylindracea could be potentially harvested.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.5
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• pp.725-733
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• 2010

A simulator is proposed in this paper for predicting the RF signal level after propagating over sea and land surfaces. Various sea and land types and transmit/receive antenna patterns, as well as the locus of the transmit antenna, are considered for this simulator. At first, microwave reflection characteristics of various sea surfaces have been computed, based on an empirical formula which is developed in this study for the relation between the sea surface roughness and wind speed. Then, microwave reflections from land surfaces such as forests, agricultural areas, and bare surfaces, are computed using the first-order vector radiative transfer theory. Finally, the signal paths over sea and land surfaces are found using the ray tracing technique and the digital elevation model, and the signal level received by a receiving antenna is computed by the using the reflection coefficients of sea and land surfaces and the signal paths.

• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.224-230
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• 1996

Randomly amplified polymorphic DNA(RAPD) analysis was applied to detect the molecular polymorphisms in Gentiana scabra var. buergeri. A high level of molecular variability was found among wild plants and cultivars. In genetic analysis, eight of twenty primers were selected and 54 amplification products ranged 2. 2 to 0.2 kb were compared. Twenty - nine amplified products showed polymorphic, while five were monomorphic. Twenty of line specific bands were found. In genetic similarity and cluster analysis using PCR products, three wild plants collected from Naejangsan, Daedunsan and Keojedo and one cultivar Seochunjaerae were grouped into one cluster, while cultivar Jinbujaerae and Japanese line separated into another clusters, respectively. The identification of DNA polymorphisms by the RAPD technique will facilitate the selection of the lines from different origin.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.6
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• pp.101-115
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• 2021

The purpose of this study is to evaluate the compatibility of the vegetation index between the two satellites and the applicability of agricultural monitoring by comparing and verifying NDVI (Normalized Difference Vegetation Index) based on Sentinel-2 and Terra MODIS (Moderate Resolution Imaging Spectroradiometer). Terra MODIS NDVI utilized 16-day MOD13Q1 data with 250 m spatial resolution, and Sentinel-2 NDVI utilized 10-day Level-2A BOA (Bottom Of Atmosphere) data with 10 m spatial resolution. To compare both NDVI, Sentinel-2 NDVIs were reproduced at 16-day intervals using the MVC (Maximum Value Composite) technique. As a result of time series NDVIs based on two satellites for 2019 and compare by land cover, the average R² (Coefficient of determination) and RMSE (Root Mean Square Error) of the entire land cover were 0.86 and 0.11, which indicates that Sentinel-2 NDVI and MODIS NDVI had a high correlation. MODIS NDVI is overestimated than Sentinel-2 NDVI for all land cover due to coarse spatial resolution. The high-resolution Sentinel-2 NDVI was found to reflect the characteristics of each land cover better than the MODIS NDVI because it has a higher discrimination ability for subdivided land cover and land cover with a small area range.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.316-322
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• 2011

BACKGROUND: Pesticides concentration was monitored in 50 agricultural lakes, and ecological risk for aquatic organism was assessed using risk quotient (RQ) and probabilistic methods. METHODS AND RESULTS: Pesticides concentrations detected in 50 agricultural lakes during peak season (June and September) were in the range of $0.17{\sim}0.99{\mu}g/L$. The RQ for algae and the other species was estimated to be 0.25 and below 0.01, indicating medium risk and no risk. Oxadiazon predominantly contributed to RQ value of 99% for algae, fishes, and amphibians. In terms of hazardous concentration at 5% of species ($HC_5$), ecological risk quotients (ERQ) for oxadiazon ranged from 0.18~0.33, showing a medium risk level. Overall, the concentrations of pesticides were much lower than $HC_5$), value. Probability of combined ecological risk for pesticides ranged from 1.82% to 2.41%. CONCLUSION(s): Combined ecological risk probability did not exceed the acceptable level of 5%, indicating no ecological risk for selected aquatic species. This study suggests that regular ecological risk assessment (ERA) will be required to protect and manage an agricultural lake. Not only ERA at screening level by comparing exposure with toxic effects for aquatic species also advanced ERA technique considering species in indigenous to Korea, chronic toxicity, pulse dose, fate, and environmental factors should be required.

• Journal of Agricultural Extension & Community Development
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• v.22 no.2
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• pp.135-144
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• 2015

Competitiveness has been associated in the tourism literature as a crucial factor for the success of tourist destinations. This study is to develop indicators that measure destination competitiveness of rural tourism townships in Korea. It was conducted via a Delphi technique and the analytical hierarchy process method. After four rounds of discussions, the panel members reached consensus on a set of 27 indicators with three dimensions which are attractor (resource, infrastructure, and tourism products), assistance (tourism business assistance and value-added processing assistance), and planning and management (planning for development, capacity for management). This set of destination competitiveness indicators can serve as a starting point for devising a set of indicators at the local level in order to be useful rural tourism sector manager and administrators. The selected indicators are measurable, demand driven and practical to show the real performance in rural destination.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.2
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• pp.53-62
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• 1986

An Idea of Standard Rural Area(SRA), the rural areas which have higher ruralities of the rice cropping region and also higher urban characteristics, was conceptualized to develop the tentative basic indices necessary for rural settlement design in reclaimed land. The SRA's were determined by a technique of the principal component analysis with relevant data from 81 counties or cities located in the west side of Korea(Chon-Nam,Chon-Buk, Chung-Nam, Kyung-Ki Do).By the definition of the SRA, the principal component analysis is seperately carried out by two subworks, analyses of rurality and urban characteristics. From the analysis, rurality of the SRA is characterized by four components which appears to describe the scale of farm management, intensive farming, soundness of farming and farming basis on rice cropping, while urban characteristics of the SRA by three components to describe the accessibility, keeping ratio of infrastructures and level of medical services. Through grouping and synthesizing two characteristics of all counties by each component score, 24 counties were classified as urban-rural harmonized region which is the same result as that obtained from the extraction index being more than 50% of available area to total area except 1 county. Therefore, SRA is defined as the group of counties having more than 50% of available area to total area.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.2
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• pp.111-122
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• 1994

In this study, an algorithm which can be applied to the optimum design of simple steel plate girders was developed, and efficient optimization strategies for the solution of algorithm were found out. The optimum design algorithm consists of 3-levels of optimization. In the first and second levels of optimization, the absolute maximum bending moment and shearing force are extracted and in the third level of optimization, the optimum cross section of steel plate girder is determined. For the optimum design of cross section, the objective function is formulated as the total area of cross section and constraints are derived in consideration of the various stresses and the minimum dimension of flange and web based on the part of steel bridge in the Korea standard code of road bridge. Sequential unconstrained minimization technique using the exterior penalty function method(SUMT-EP), sequential linear programming(SLP) and sequential quadratic programming (SQP) are proved to be efficient and robust strategies for the optimum design of simple plate girder cross section. From the reliable point of view, SLP is the most efficient and robust strategy and SQP is the most efficient one from the viewpoint of converguency and computing time.