• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.374-380
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• 2017

Pine wilt disease (PWD) is one of the hazardous pine tree diseases in whole world. In Korea, PWD has been spreading since it was first observed in Busan in 1988. Dispersion of PWD is mainly mediated by its vectors such as Japanese pine sawyer. In this study, we characterized environmental condition including meteorological factors, geographical factors, and land use factors influencing on the occurrence of PWD. The occurrence data of PWD were collected at 153 sites where were the initial occurrence sites of PWD in local government regions such as city, Gun, or Gu scale. We used Akaike Information Criterion (AIC) to evaluate the relative importance of environmental variables on the discrimination of occurrence or absence of PWD. The results showed that altitude, slope, and distance to road were the most influential factors on the occurrence of PWD, followed by distance to building. Finally, our study presented that human activities highly influenced on the long term dispersal of PWD.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1652-1657
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• 2021

Nuclear materials can be utilized not only for peaceful uses, but also for military purposes; hence, the international community has devoted itself to the control, management and safeguarding of nuclear materials. Nuclear materials are of varying degrees of usability for development of nuclear weapons. Thus, several methods for assessing the attractiveness of nuclear materials for nuclear weapons purposes have been proposed. When these methods are applied to unirradiated depleted, natural, and low-enriched uranium (DU, NU, and LEU), they are certainly classified as non-attractive nuclear materials. However, when nuclear material attractiveness is to be evaluated for potential radiological dispersal device (RDD) uses, it is required to develop a different method for the different aspects and factors. In the present study, we derived a novel method for evaluating nuclear material attractiveness for use in RDD development. To this end, the specific activity and dose coefficient were identified as the two sub-factors, and, in consideration of those, the mass causing detrimental health effects was determined to be the main factor impacting on nuclear materials attractiveness. Based on this factor, the attractiveness of unirradiated DU, NU, and LEU for RDD use was qualitatively compared with that of ¹³⁷Cs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.4
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• pp.365-370
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• 2010

The pollen dispersal by wind can make an important to understanding the viability and evolution of plants in ecological and agricultural science. Modelling can be applied to evaluate concerns about the spread of engineered pollens from genetically modified (GM) crops. Here, we are using gamma model to estimate the level of dispersal distance of pollen in the cross-pollination between two different maize (Zea mays L.) cultivars in GMO field of Korea University during the year 2010. The result of estimation of model indicates maximum pollen dispersal distance of estimated proportion of cross-pollination of maize was reached to 0.1% in 525 meter northwest due to the wind. We identify further measurements necessary to improve the accuracy of the model predictions.

• Journal of the Korea Institute of Building Construction
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• v.16 no.1
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• pp.77-85
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• 2016

This study provides the numerical model to assess retrofit and strengthen levels in the dispersal and combat facilities. First of all, it is verified that direct-hitting projectiles are more destructive to the structures rather than close-falling bombs with explosion tests. The protective capacity of dispersal and combat facilities, which are modeled with soil uncertainty and structural field data, is analyzed through finite element method. With structural survivability and facility data, the logistic regression model is drawn. This model could be used to determine the level of the retrofit and strengthen in the dispersal and combat facilities of contact areas. For more reliable model, it could be better to identify more significant factors and adapt non-linear model. In addition, for adapting this model on the spot, appropriate strengthen levels should be determined by hands on staffs associated with military facilities.

• The Korean Journal of Quaternary Research
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• v.21 no.2
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• pp.49-53
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• 2007

• The Journal of the Korean dental association
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• v.26 no.1 s.224
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• pp.65-71
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• 1988

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.209-214
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• 2015

The Mesostigmata is an order of Subclass Acari either parasiting to diverse invertebrates or free-living predatory in terrestrial ecosystem. Phoresy is one of the unique behaviors of wingless arthropod dispersal by attaching winged arthropods. We collected mites attached on the dorsal part of abdomen adult sciarid fly, from mushroom culture. The mites were identified as Arctoseius cetratus Sellnick, 1940 in the family of Ascidae. Arctoseius cetratus has short J2, Z1, Z2, and S1, S2 setae, not reaching the bases of following setae. Posterior half of dorsal shield with longitudinal garland of puncta between J and Z setae, peritremes extending anteriorly to midlevel of coxaII. The genus Arctoseius and species Arctoseius cetratus are the first record in Korea. We provided the detail description of the species including the identification key in the family with some ecological notes.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.121.1-121
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• 2003

Dispersal of Xanthomonas axonopodis pv. citri, causing citrus bacterial canker disease on Unshiu orange was investigated at previously infested plots at Seogwipo in Jeju island of Korea. The bacterial pathogen overwintered in lesions started to multiply at tate May, and disease firstly observed one month after detection of phage from lesions. The disease gradually increased, however, it dispersed non-directionally to nearby plants from inoculum sources. Diseased plants were aggregated to form a cluster throughout the experiment. Population dynamics of phage on symtomless leaf surface and the disease severity were compared in the nursery, Increase of phage population on symptomless leaf surface preceded one month to that of the disease severity Population of phage increased constantly from late July to October, however, the disease severity decreased from late August to late October. It was assumed that the decrease of disease severity might be due to disease-induced defoliation.

• Journal of National Security and Military Science
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• s.7
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• pp.129-154
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• 2009

The principles of military operations(principles of war) are the fundamental principles ruling warfighting that made based on the experiences of wars from the time of ancient Greeks to the World War II. Recent wars such as Iraq War showed us the change of environment of war and the style of waging a war. It is believed that future war will be executed with the style of Rapid Deceive Operations, Effect Based Operations, Network Centric Operations. Therefor the principles of war which we use should be reconsidered whether it is useful or not in future warfare. By considering the present principles of operation which are using in many countries and analysing the style of waging future war, we suggest new principles of operations : principle of gravity, principle of mass and dispersal, principle of disturbance, principle of speed, principle of paralysis, principle of synchronization and integration, principle of leadership, and principle of information.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.181-188
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• 2003

In this study, soil seed and bud bank analysis were performed to abbess the mass of potential vegetation in soils less than 1 year old after covered and estimate the amount of seed bank transport through construction in urban area. The ratio of exotic species number to total species number in study sites and the landfill control site was 0.29 and 0.39, respectively. All plots pooled, mean species number and total mean seedling density per $\m^2$ in the top 10 cm of soil was 11$\pm$0 (average$\pm$S.E.) and 8037$\pm$221.Total plant seeds by artificial soil trasnsfer were estimated to be 53 thousand million $m^{-2}yr^{-1}$ in 10 cm soil depth. It reveals that soil transfer accelerates seeds and vegetation movement and makes urban vegetation mixed and common.