• Research in Plant Disease
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• v.27 no.2
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• pp.49-60
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• 2021

Cashew (Anacardium occidentale L.) is an important cash crop in Tanzania as a source of income to cashew growers and provides foreign exchange for the country. Despite its significance, the crop is threatened by fast spreading disease known as cashew Fusarium wilt caused by Fusarium oxysporum. Field assessment and laboratory tests were conducted to determine incidences of the disease, severity, ecological factors that influence them and explored the pathogen host specificity in six cashew growing districts. The results revealed significant (P<0.001) variation of disease incidences and severity among the studied districts. The results further revealed that there is both positive and negative correlation between the incidence and severity of the disease versus the evaluated ecological factors. The soil pH, soil temperature, air temperature, and relative humidity depicted positive correlation of disease incidence and severity versus ecological factors at ρ=0.50 and ρ=0.60, ρ=0.20 and ρ=0.94, ρ=0.11 and ρ=0.812, ρ=0.05 and ρ=0.771 respectively while nitrogen, phosphorus, and carbon depicted negative correlations at ρ=-0.22 and ρ=-0.58, ρ=-0.15 and ρ=-0.94, ρ=-0.19 and ρ=-0.12 respectively. In terms of host range, none of the weed species was found to be a carrier of Fusarium pathogen implying that it is host specific or semi selective. The results revealed that the tested ecological parameters favor the growth and development of Fusarium pathogen. Thus, management of the disease requires nutrients replenishment and soil shading as essential components in developing appropriate strategies for the control and prevention of further spread of the disease.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.121-124
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• 2002

King Oyster(Pleurotus eryngii) is one of the most promising mushrooms produced on the domestic farms. The quality as well as quantity of King oyster is sensitively affected by micro climate factors such as temperature, relative humidity, $CO_2$ concentration, and light intensity. To safely produce high-quality King oysters year round, it is required that the environmental factors be carefully controlled by well designed structures equipped with various facilities and control systems. In this study, we are focusing on carrying out growing experiment to find out reasonable range of each environmental factor together with economic and safe structures influencing on the optimal productivity of king oyster mushroom. The optimal productivity will be evaluated by considering the quality and quantity of mushroom production, energy requirements, facility construction and management cost, etc.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.130-139
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• 2016

The purpose of this paper is to analyze the problems and the sources of defective products and draw improvement plans in a small plastic boat manufacturing process using TOC (Theory Of Constraints) and statistical analysis. TOC is a methodology to present a scheme for optimization of production process by finding the CCR (Capacity Constraints Resource) in the organization or the all production process through the concentration improvement activity. In this paper, we found and reformed constraints and bottlenecks in plastic boat manufacturing process in the target company for less defect ratio and production cost by applying DBR (Drum, Buffer, Rope) scheduling. And we set the threshold values for the critical process variables using statistical analysis. The result can be summarized as follows. First, CCRs in inventory control, material mix, and oven setting were found and solutions were suggested by applying DBR method. Second, the logical thinking process was utilized to find core conflict factors and draw solutions. Third, to specify the solution plan, experiment data were statistically analyzed. Data were collected from the daily journal addressing the details of 96 products such as temperature, humidity, duration and temperature of heating process, rotation speed, duration time of cooling, and the temperature of removal process. Basic statistics and logistic regression analysis were conducted with the defection as the dependent variable. Finally, critical values for major processes were proposed based on the analysis. This paper has a practical importance in contribution to the quality level of the target company through theoretical approach, TOC, and statistical analysis. However, limited number of data might depreciate the significance of the analysis and therefore it will be interesting further research direction to specify the significant manufacturing conditions across different products and processes.

• Journal of Forest and Environmental Science
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• v.27 no.3
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• pp.169-181
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• 2011

The purpose of this study was to understand the geographical and environmental distribution of animals and plants in Baekdudaegan region using field survey and GIS data. Crucial factors were selected and analyzed to understand the distributional characteristics of wild animals (16 species in 5 orders) and rare endemic plants (20 species in 12 orders). These crucial factors include stand factor (forest type, DBH class, and crown density), soil factor (bed rock, soil texture, and organic matter), geographical factor (elevation, slope, aspect) and climatic factor (temperature, rain fall, humidity). Finally, ten crucial factors were selected by statistical analysis and categorized for analyzing geographical and environmental features. Three orders such as Rodentia, Carnivora, and Artiodactula in wild animal showed the similar habitat characteristics with the small diameter and the elevation range from 801 to 1,000m. The Hydropotes inermis of Artiodactyla and Rattus norvegicus of Rodentia were different in the type of orders, but they had the similar habitat characteristics with the coniferous forest and loam. On the other hand, four orders such as Tubiflorales, Liliales, Ericales, and Rhamnales in the rare and endemic plants were showed high occurrence rate in the organic matter between 4 and 6%. The Rodgersia podophylla of Rosales and Gastrodia elata Blume of Microspermae were different in the type of orders, but they had the similar habitat characteristics with the stand factor and soil factor.

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.622-629
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• 2019

Objectives: The occurrence of norovirus food poisoning in South Korea has been reported since 2003. This study was performed to investigate the characteristics of norovirus food poisoning outbreaks in Korea from 2006 to 2015 and to analyze the relationship between these outbreaks and climate factors. Methods: Data on norovirus food poisoning outbreaks were obtained from the Korea Ministry of Food and Drug Safety. Data on climate factors were obtained from the Korea Meteorological Administration. Frequency analysis and Pearson's correlation analysis were adopted for this study. Results: During the study period, norovirus was the greatest contributing factor of food poisoning outbreaks. Approximately half of the outbreaks of norovirus food poisoning occurred in winter. Average temperature, highest and lowest temperatures, precipitation, number of days with rainfall, and humidity all had a significant negative correlation with monthly number of outbreaks of norovirus food poisoning (p<0.05). Among these, the lowest and average temperature showed higher correlation coefficients. However, the sum of the outbreaks in spring and autumn was similar to that of winter, and more than one-third occurred in group meal-service settings, including school lunches. This was strongly assumed as the use of norovirus-contaminated groundwater for preparation of meals in some settings. Conclusion: The cold and dry of the winter season in Korea may assist the transmission of norovirus. Also, the use of groundwater in group meal service is suspected of inducing a larger scale of norovirus food poisoning. Both health authorities and community-based prevention and control measures are required to respond to these complex etiological outbreaks.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.361-370
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• 1982

The effects of climatic factors on organisms lire variable and complex, and it, however, can be interpreted in terms of those on the distribution and those on the population densities. The distribution of an organism may largely be determined by the temperatures, except some temporal organisms which are depended on the air mass movements. Population density of an organism is determined by various climatic factors, such as previous winter temperature, temperature of growing season and rainfall. The start of growing season of the rice plants has been shifted to earlier since last decade in Korea. This may mean that the overall climatic condition during the growing season might be considerably different from those in past years, and such a difference in climatic conditions might have close relation with the recent status of the diseases and insect pests through direct effects on the physiology and population dynamics of the organisms, as well as through on the biotic associations of the pest organisms. The white back planthopper and brown planthopper have become the key insect pests in Korea in recent years. They are migratory and have high reproductive pontentials and more generations than average residential insects. The synchronization of the migrants and physiological condition of the rice plants seems to be the important factors in relation to the recent outbreaks of these insects; the high reproductive rate can be obtained with the growth stage of rice being 30-50 days after transplanting. The modication of the microclimate associated with high plant density and some other introduced new cultural techniques also have some relation with the outbreak. The key diseases of the rice are the blast disease, sheath blight and the bacterial leaf blight. For the rice blast, the seedling blast and leaf blast during the early growing season and the neck blast, have become more serious, the former may be related to hotbed nursery and the later may be related to the high humidity in early August, and synchronization of the heading time which has been shifted to early part from middle or late part of August. In general, for the rice diseases, the development of the new races have been the most serious which are largely resulted from the introduction of the new varieties, but it also seems to be related with the prolonged periods of the favorable condition associated with the shifted growing seasons. In general, the diseases and insect pest problems have become much more variable and complex, and control measures should be based on the thorough knowledge of the ecology of the pest organisms, that is, effects of various environmental factors on the disease cycle; spore release, spore deposition, infection, colonization and sporulation of the disease organisms, and those on the development, reproductive potentials, dispersal, age specific responses of the insects. The well organized real-time pest management systems, such as alfalfa weevil management system developed at the Purdue University in U.S., is the prime importance for the implementation of the pest management principles.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.1
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• pp.11-17
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• 2023

In this study, the correlation analysis between total system error and environmental factor variables was performed to confirm the effect on the performance of the integrated navigation system by various environmental factors. To collect flight data of hybrid vertical take-off and landing UAVs, scenarios including various turning sections and straight sections such as left turn, right turn, turning rate, and path change angle were selected, and environmental data of wind direction, wind speed, temperature, air pressure, and humidity were collected in real time through weather station. As a result of the correlation analysis between the collected flight data and environmental data, it was concluded that the performance of the integrated navigation system by environmental factors within the collected data was not significant affected and was robust.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.177-182
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• 2024

A consumer's decisions are made by affection of product. Affection has types: evaluation, mood, emotion and sensibility that means unconscious changes. Previous researches have clarified weather factors affect to sensibility that means weather factors may have causal effects to consumer's decision making. This research utilize weather information from KMA(Korea Meteorological Administration) and SNS geographical information and text to make weather sensibility model, and clarify the model shows significant change to online shop customer's purchase behavior(purchase frequency) by merging customer's address information and geometric information of the model for apply weather model. As a result, a model utilize daily precipitation, sunshine hours, average ground temperature, and average relative humidity makes significant result to e-commerce purchase behavior frequency.

• Journal of Conservation Science
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• v.31 no.4
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• pp.387-393
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• 2015

Damages of wooden cultural heritages caused by various bio-species have been a trend that is increasing on climate change. The decay and bio-damage caused by microbial organisms or insect species are also known to factors of the shape changes and structural problems of wooden cultural heritages. There are so many phenomenons of damage and weathering in wooden cultural heritage for many years and particularly termite can threaten seriously wooden cultural heritage. We investigated with respect to internal and external environment and termite inhabitation around the wooden cultural heritage in Jeollanam-do, Jeollabuk-do, and Jeju-do. As this investigation results, we confirmed that there were the difference in between resident and non-resident about temperature, humidity, moisture contents of wooden building. Resident building is high temperature but humidity and moisture contents is low and these factors are sources of inhabitation condition change about insects as termites. Now we suggest to carry out in parallel to the target wooden cultural heritage and the surrounding habitat for wooden cultural heritage termite damage investigation. Also with the chemical control methods, we must consider necessary to present eco-friendly control management such as construction of heating facilities, residential status, periodic management.

• Journal of Korean Society for Quality Management
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• v.28 no.4
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• pp.16-28
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• 2000

Recently days, High Accelerated Life Test of electrical and electronic parts is increasing its importance. This study set the hypothesis to develop the method that was analysis and application of HALT for the automotive electrical and electronic parts, it used Arrhenius's Model and Eyring's Model, and ESS theory. Validity of application is proved by other test data. Especially, this study emphasis on utility of acceleration to temperature, humidity, voltage, mechanical stress and other stress. In this study set the pattem of practical application. Therefore, this study emphasis on the application of the HALT and the use of other parameter by acceleration reliability test data. The result of this study is as follows. 1) There is relationship between molar weight and material constant. 2) Characteristic of material is operating acceleration factor as well as parts failure factors. Of course, according to the characteristic of material, activation energy is often more important than molar weight. But it will be defined by more testing and improvements in practical application.