• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.54-60
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• 2015

The autoignition temperature (AIT) of a material is the lowest temperature at which the material will spontaneously ignite. The AIT is important index for the safe handling of flammable liquids which constitute the solvent mixtures. This study measured the AITs of n-decane+ethylbenzene system by using ASTM E659 apparatus. The AITs of n-decane and ethylbenzene which constituted binary system were $210^{\circ}C$ and $430^{\circ}C$, respectively. The experimental AITs of n-decane+ethylbenzene mixture were a good agreement with the calculated AITs by the proposed equations with about $11^{\circ}C$ A.A.D.(average absolute deviation).

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.3
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• pp.128-142
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• 2009

A lot of efforts have been made to resolve balancing problems between flux and source term and most finite volume models under development have been applied to simple channels such as imaginary and experimental channels. However, a number of numerical problems which can not be found in simple channels occur in the application to natural rivers and the problems should be resolved to apply finite volume models to natural rivers. In this study, 2D finite volume model which is applicable to natural rivers was developed and the accuracy of the developed model was validated through the application of partial dam break In addition, a simple and efficient 2D mesh generation method was suggested and the method can be accurately reflected to 2D mesh converted from surveyed cross sections in Han-river using GIS. The accuracy and applicability of the developed model on natural rivers were verified by performing simulation on Han-river using the generated mesh and comparing computed water elevation with measured water elevation.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.439-453
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• 2018

The purpose of this study is to evaluate water quality characteristics of main drinking waters in natural parks, for providing the basic information of water quality and to propose the appropriate management method. to maintain the water quality standards. As a result of the analysis, microorganisms were mostly detected in the nature of natural park. And some sites are currently using UV sterilizer and ozone treatment, and it is considered appropriate to extend the use to other main drinking water. It is also good to boil drinking water at home. Turbidity is expected to improve through environmental cleanup. Overall, the main drinking water in the natural park is suitable for water quality standards, and it is considered that maintenance such as cleaning is necessary.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.175-179
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• 2018

Study Design: Case report. Objectives: We report 3 cases of loss of disc height after spontaneous regression of a herniated lumbar disc. Summary of Literature Review: Reports of spontaneous regression of a herniated lumbar disc were identified. Materials and Methods: We conservatively treated 3 patients who were diagnosed with a herniated lumbar disc. During outpatient follow-up, radiating pain improved in all patients, but they complained of chronic lower back pain. Magnetic resonance imaging (MRI) was performed for diagnostic purposes. Results: On MRI, spontaneous regression of the herniated lumbar discs was observed, but loss of disc height was also found. Conclusions: A herniated lumbar disc may be a risk factor for loss of disc height. It is important to recognize that a patient with a herniated lumbar disc can struggle with chronic lower back pain even if spontaneous regression of the herniated lumbar disc occurs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.294-300
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• 1985

This experiment was carried out to study the root and the other major agronomic traits of barley cultivars at the greenhouse and natural conditions for the accelerating of breeding generation. The barley cultivars tested in this experiment were Kangbori, Olbori and Suwon 18. In early stages, total dry weight of barley was vigorously increased at the greenhouse condition, whereas it was less increased than that of natural condition after heading stages. In dry root weight, it was decreased at natural condition rather than greenhouse condition. The appearance of harvest dry root weight was at four weeks after heading at natural condition and seven weeks after heading at greenhouse condition, respectively. It showed different tendency in T/R ratio, indicating the continuous increased at natural and greenhouse condition, even if there is more or less decrease until tillering stage at greenhouse condition.

• Journal of Korea Technology Innovation Society
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• v.11 no.3
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• pp.335-351
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• 2008

The paper constructs the economic theory of sleeping patents in the knowledge-based economy. Starting with the definition of sleeping patents, we suggest the types of sleeping patents, intended and unintended ones. While intended sleeping patents are divided into 'for-defending technological position' and 'for-describing past technology', unintended sleeping patents include frictional, intrinsic, market-deficient, and institutional ones. We also introduce the concept of the natural rate of sleeping patent and measure the social loss due to sleeping patents. The study can contribute to solving policy problems for utilizing registered patents. For example, if we measure the natural rate of sleeping patent in Korea, we can estimate 'tolerable rate of sleeping patent' and control the extend of policy intervention for patents utilization. Since we invest the theory of sleeping patents firstly, the suggested concepts should be elaborated through further discussion in depth.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.1
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• pp.39-44
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• 2004

A Giant cell tumor of bone has unusual characteristics of pulmonary metastasis as well as local aggressiveness. Clinical courses of pulmonary metastasis of benign giant cell tumor vary including rapid growth, continuously slow growth or spontaneous regression. We report a case of extensive pulmonary metastasis of giant cell tumor of bone, which regressed spontaneouly.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.51-56
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• 2011

In this paper, we presents an algorithm which restores lost data or increases resolution of a DTM(Digital terrain model) using fractal theory. Terrain information(fractal dimension and standard deviation) around the patch to be restored is extracted and then with this information and original data, the elevations of cells are interpolated using the random midpoint displacement method. The results of the proposed algorithm are compared with those of the bilinear and bicubic methods on a fractal terrain map.

• Korean journal of applied entomology
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• v.26 no.1 s.70
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• pp.37-41
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• 1987

Sporulation potential and conidia release phase of Pyricularia oryzae on lesions under the natural conditions were measured in 1985 and 1986 leaf blast seasons. The amount of conidia produced in lesions on detached leaves and conidia released under the field condition were reached peak at $5{\sim}7$ days after lesion appearance. The maximum numbers of conidia produced and released were 16,200 and 15,900, respectively. Conidia release under the natural conditions lasted for 30 days.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.21-27
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• 2013

The lowest values of the AITs(Autoignition temperatures) in the literature were normally used fire and explosion protection. In this study, the AITs of n-Propanol+n-Octane system were measured from ignition delay time(time lag) by using ASTM E659 apparatus. The AITs of n-Propanol and n-Octane which constituted binary systems were $435^{\circ}C$ and $218^{\circ}C$, respectively. The experimental ignition delay time of n-Propanol+n-Octane system were a good agreement with the calculated ignition delay time by the proposed equations with a few A.A.D.(average absolute deviation).