• The Plant Pathology Journal
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• v.39 no.4
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• pp.319-334
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• 2023

Plant disease is an important factor affecting crop yield. With various types and complex conditions, plant diseases cause serious economic losses, as well as modern agriculture constraints. Hence, rapid, accurate, and early identification of crop diseases is of great significance. Recent developments in deep learning, especially convolutional neural network (CNN), have shown impressive performance in plant disease classification. However, most of the existing datasets for plant disease classification are a single background environment rather than a real field environment. In addition, the classification can only obtain the category of a single disease and fail to obtain the location of multiple different diseases, which limits the practical application. Therefore, the object detection method based on CNN can overcome these shortcomings and has broad application prospects. In this study, an annotated apple leaf disease dataset in a real field environment was first constructed to compensate for the lack of existing datasets. Moreover, the Faster R-CNN and YOLOv3 architectures were trained to detect apple leaf diseases in our dataset. Finally, comparative experiments were conducted and a variety of evaluation indicators were analyzed. The experimental results demonstrate that deep learning algorithms represented by YOLOv3 and Faster R-CNN are feasible for plant disease detection and have their own strong points and weaknesses.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.1
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• pp.9-15
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• 2020

The cooperation with other work types and designing procedure in plant industry and engineering showed clear differences from general construction industries. Current problems are that design's consistency is reduced because of the false system of interface and it ultimately causes frequency changes of design and delayed submission of final book. To solve the problems, the improvements of designing procedure were studied by focusing on the field of architectural designing and the range was limited from power plant construction industry to engineering designing field. If combining GA with the field of architectural designing and receiving data previously, it's possible to conduct expectable designing on small changes in the future, so it's expected to improve greatly cooperation with interface among the work types of power plant engineering received previously from the aspect of consistency. For the application of designing tool, a checklist, interim check will be conducted if progressed by list's division in the designing procedure, not book's completing period. In the interface among the designing work types, direct confirmation and revision must be conducted. In case of 3D modeling, the reflection of input data must be conducted from the basic designing so as to solve interferences intensively.

• Mycobiology
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• v.39 no.3
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• pp.194-199
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• 2011

Pepper anthracnose caused by Colletotrichum species is one of the most important limiting factors for pepper production in Korea, its management being strongly dependent on chemicals. The aim of this work was to evaluate the possibilities of using silver nanoparticles instead of commercial fungicides. In this study, we evaluated the effect of silver nanoparticles against pepper anthracnose under different culture conditions. Silver nanoparticles (WA-PR-WB13R) were applied at various concentrations to determine antifungal activities in vitro and in the field. The application of 100 ppm concentration of silver nanoparticles produced maximum inhibition of the growth of fungal hyphae as well as conidial germination in comparison to the control in vitro. In field trials, the inhibition of fungi was significantly high when silver nanoparticles were applied before disease outbreak on the plants. Scanning electron microscopy results indicated that the silver nanoparticles caused a detrimental effect on mycelial growth of Colletotrichum species.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.1
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• pp.149-158
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• 2002

The carbonation process is affected by both the concrete material properties such as W/C ratio, types of cement and aggregates, admixture characteristics and the environmental factors such as $CO_2$ concentration, temperature, humidity. Based on results of preliminary study on carbonation, this study is to develop a carbonation prediction model by taking account of $CO_2$ concentration, temperature, humidity ad W/C ratio among major factor affecting the carbonation process. And to constitute a model formula which correspond to the mix design of the nuclear power plant, test coefficient that correspond to the design of the nuclear power plant is obtained based on the results of accelerated carbonation test. Also a field coefficient which is obtained based on results of the field examination is included to improve the conformity of the actual structures of nuclear power plant.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.50-61
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• 1994

Biological control of important fungal diseases such as Phytophthora blight of red pepper, gary mold rot of vegetables, and powdery mildew of many crops was attempted using an antagonistic bacterium, Bacillus sp. AC-1 in greenhouses and fields. The antagonistic bacterium isolated from the rhizosphere soils of healthy red pepper plant was very effective in the inhibition of mycelial growth of plant pathogenic fungi in vitro including Phytophthora capsici, Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea, Valsa mali, Fusarium oxysporum, Pythium ultimum, Alternari mali, Helminthosporium oryzae, and Colletotrichum gloeosporioides. Culture filtrate of antagonistic Bacillus sp. AC-1 applied to pot soils infested with Phytophthora capsici suppressed the disease occurrence better than metalaxyl application did until 37 days after treatment in greenhouse tests. Treatments of the bacterial suspension on red pepper plants also reduced the incidence of Phytophthora blight in greenhouse tests. In farmers' commercial production fields, however, the controlling efficacy of the antagonistic bacteria was variable depending on field locations. Gray mold rot of chinese chives and lettuce caused by Botrytis cinerea was also controlled effectively in field tests by the application of Bacillus sp. AC-1 with control values of 79.7% and 72.8%, respectively. Spraying of the bacterial suspension inhibited development of powdery mildew of many crops such as cucumber, tobacco, melon, and rose effectively in greenhouse and field tests. The control efficacy of the bacterial suspension was almost same as that of Fenarimol used as a chemical standard. Further experiments for developing a commercial product from the antagonistic bacteria and for elucidating antagonistic mechanism against plant pathogenic fungi are in progress.

• Research in Plant Disease
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• v.23 no.1
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• pp.19-34
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• 2017

Recent worldwide demand for organic and sustainable agriculture products is driving the development of formulations of biopesticides effective in the field. Biopesticides have the benefit of environmentally-friendly qualities. However, biocontrol approaches largely have been ineffective in controlling plant pests in field conditions. Previously, we developed a cost-effective biocontrol formulation containing chitin and chitinase-producing biocontrol bacteria with field efficacy. This formulated product has successfully suppressed various plant diseases in the field conditions. In this review, we focus on ecological aspects and the potential mechanisms underpinning the success of chitinase-producing bacteria. In addition, we discuss the possibility on-site cultivation of the formulated products to further strengthen the approach as being farmer friendly and successful.

• Mycobiology
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• v.41 no.1
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• pp.47-55
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• 2013

Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination between biocontrol agents and chemical inducers recorded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in field.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.128-129
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• 2005

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.613-616
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• 2007

The main structures that comprise a tidal power plant are turbine structure, sluice structure, tide embankment and gate. Since these structures are founded on seabed ground, an extensive geotechnical site investigation to evaluate the engineering properties of field soils must be conducted prior to design and construction. According to the results of geotechnical site investigation conducted at the planned site for construction of Incheon bay tidal power plant, soft ground generally lie 7 meters below the seabed surface level. This research suggests the reliable and economical design of foundations and ground improvements required for construction of main structures in Incheon bay tidal power plant, with considerations on field conditions.

• 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.