• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.149-153
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• 1998

This experiment was carried out to obtain a basic information for new variety development. The local soybean (Glycine max. L) lines used were endowed from Chungnam Agricultural Research and Extension Services. These lines were planted at upland farm of Chungnam Nat'l Univ., College of Agri. after treatment with mutagen $\gamma$-ray. All characteristics measured were decreased due to the $\gamma$-ray treatment than check except the branches of main stem of the Hannam and plant height of the Sobak. Especially the Sobak and the Eunha among these lines were shown very sensitivly than others treated with $\gamma$-ray of 15Krad. Of characteristics surveyed the nodes per plant was very sensitive to $\gamma$-ray, while the grain weight per plant, the pods per plant and the branches per plant were gradually decreased to further radioactivity about $\gamma$-ray treatment. In the Pungsan and the Sobak lines there were not shown significant between major characteristics at treatments including check. Other lines were also not shown positive correlation among characteristics except between stem diameter and branches(0.64*), grain weight and plant height(0.77**) at check of the Eunha, between stem nodes and stem diameter(0.65*) at check of the Kwangan and between number of pods and stem diameter(0.70*) at check of the Danyeop. From result this experiment, some of lines used were to be appeared characters of interest, for example, such as the short stem and the early flowering. Therefore these lines were needed more advanced generations for stability and performance.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.251-260
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• 2002

Geotextile tribes are made of sewn geotextile sheet and hydraulically or mechanically filled with dredged materials. They have been applied in hydraulic and coastal engineering in recent years(shore protection structure, detached breakwater, groins, and jetty). Therefore, it is composed of geotextile and confined fill material. Recently, new preliminary design criteria supported by model and prototype tests, and some stability analysis calculations have been studied. The stability analysis of geotextile tube is composed of geotechnical and hydrodynamic analysis. The stability check points are sliding failure, overturning, bearing capacity failure against the wave attack. In this paper are presented the stability analysis method by empirical equation and 2-D equilibrium analysis for geotextile tube. Also, the hydraulic model tests were performed to verify the theoretical stability analysis with geotextile tube shape, filling ratio, significant wave height, and so on. The results of this study show that the stability of geotextile tube depends on the tube shape, contact area, projection area. The theoretical analysis and hydraulic model test show almost the same results.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.79-85
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• 2015

Onboard fire extinguishing system is important to protect cargo and human lives and every oil tanker has foam type fire extinguishing system. Because of environmental problem, agent which contains materials such as Perfluorinated compounds are regulated and the development of the environmental friendly agent is required. The protein foam has less environmental pollution problem and has an excellent fire extinguish performance to oil fire. In the research, bivalency metal salts were added as stabilizer to increase fire resistance and stability of the foam. Ferrous sulfate, Iron chloride and Nickel chloride were used and to adjust to vessel, sea water was applied. As a stabilizer increased, the expansion ratio was raised. However 25% drainage time was decreased over 2.0 wt.% which is knowable that the foam brokes easily. The amount of generated foam was measured to check fluidity of foam and it appeared that when $FeSO_4$ 1.2 wt.% was added, the amount of generated foam reached large and also the 25% drainage time was high. To evaluate the fire extinguishing performance for oil fire, the small scale oil fire test was executed. When $FeSO_4$ 1.2 wt.% was added, fire extinguishing time was in its shortest which informs fluidity of foam and stability are important factors on fire extinguishing efficiency.

• The Korean Journal of Applied Statistics
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• v.11 no.1
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• pp.65-81
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• 1998

Simultaneous equation models, increasingly used in many detailed analyses, tend to get larger and more sophisticated to describe the structure of the study area to be close to the actual situations. In setting up such a system of equations, statistical results and simulation performance of the model as a whole may be meaningless and unrepresentative of the real world due to a structural instability that is built into the model when the equations are combined and solved simultaneously. Even though the use and subsequent analysis of an unstable system are likely to mislead us, most of the studies that take the simultaneous equation approaches neglect such a serious problem. Thus it is necessary to illustrate how to check the stability problem and apply to the actual model, then investigate how such as analysis is able to provide useful information about the structural characteristics of the model from the dynamic viewpoint.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.151-157
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• 1999

Vibrations in machine tools make many problems in precision, production efficiency, and machine performance. The relative vibration between a workpiece and a tool is very complicated due to many sources. In this study, the dynamic characteristics of a newly developed CNC lathe were analyzed and its chatter characteristics were predicted by a chatter analysis method using finite element analysis and 3 dimensional cutting dynamics. The simulated results showed very complex characteristics of chatter vibration and the borderline of limiting depth of cut was used as the stability limit. To check the validity of this method, cutting tests were done in the CNC lathe using a boring bar as a tool because boring process is very weak due to long overhang . The experimental results showed that the simplified borderline was to be considered as limiting depth of cut at which the chatter vibration starts and the stability limits depended on various cutting parameters such as cutting speed, feed and nose radius of tool.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.101-109
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• 2003

Yangdong village is located at Kangdong-myun, Kyungju, Kyungsangbuk-do, Korea. There are two major families, the Sons of Wallsung beginned from Son, So(1433∼1484) and the Lees of Yeohkang the descendant of Lee, Unjeok. They are lived together under check and help for 500 years. The village located on the hill of Ankang plain. There are Homyung mountain and Sonaiu peak in front of it and Solchang mountain on the back. 47 shaped ridges form Blue dragon to the east, and White tiger to the west. Ahnrockchon flows from north Joined Hyungsan river and flows into Youngilman. Therefore the village is located at mountain on it's back and along with stream. Buildings are deployed on the valley between hills, it is not easily detected, but it give it's atmosphere of mountain village. Village location and space composition combined with natural environment, folk belief, feng-shui, and social system of confucianism. Blended buildings affected between ruling and ruled classes or among different families shown environmental design accomplishing united cultural space. The prospect of Yangdong village, a mountain village, expressed two sides of visible scenery of open inside and invisible from outside. Observation point such as head family house, pavilion, and village school are deployed at the point taking bird's-eye view, which striving mental stability.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.207-216
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• 2004

IPsec protocol has been developed to provide security services to Internet. Recently IPsec is implemented on the various operating systems Hence, it is very important to evaluate the stability of the Ipsec protocol as well as other protocols that provide security services. However, there has been little effort to develop the tools that require to evaluate the stability of IPsec protocols. Therefore, in this paper, we develope the security requirements and suggest a security evaluation system for the Internet packet protection protocols that provide security services at the If level that can be used to check if the security protocols Provide the claimed services correctly This system can be used as debugging tool for developing IPsec based security system.

• Journal of Korean Society of Disaster and Security
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• v.10 no.1
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• pp.55-60
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• 2017

The dyeing sludge can be weakened by inflow of rainfall or absorption of moisture after it is buried in a waste landfill. This study tested the dyeing sludge and earth/sand mixture to check the problem when the dehydrated dyeing sludge is buried in a waste landfill. When the dyeing sludge was left idle with high water content inside a landfill with poor draining for a long period, the water permeability decreased to around 3/100 level and the compressibility increased by 1.4 times compared to the dyeing sludge at a dyeing factory. The study result indicated that it was important to reduce the water content inside the landfill for stability. Also, the facilities to secure the drainage path and eliminate leachate were needed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.527-528
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• 2016

In this paper, to provide a binaural beat in the method of treatment of sleep disorders. Let the sound of different frequencies, the waveform of the brain resonate at a specific frequency, to induce a stable state, is converted over to a high-frequency audio frequency, improves the listening experience. To target the three college students for the results performance evaluation of, conducted an experiment on the sense of stability at the time of sleep, in the process, the brain waves were measured as a means to check the degree of sense of stability.

• Journal of computational fluids engineering
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• v.7 no.1
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• pp.10-19
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• 2002

The non-staggered(collocated) grid approach in which all the solution variables are located at the centers of control volumes is very popular for incompressible flow analyses because of its numerical efficiency on the curvilinear or unstructured grids. Rhie and Chow's paper is the first in using non-staggered grid method for SIMPLE algorithm, where pressure weighted interpolation was used to prevent decoupling of pressure and velocity. But it has been known that this non-staggered grid method has stability problems when pressure fields are nonlinear like in natural convection flows. Also Rhie-Chow scheme generates large numerical diffusion near curved walls. The cause of these unwanted problems is too large pressure damping term compared to the magnitude of face velocity. In this study the magnitude of pressure damping term of Rhie-Chow's method is limited to 1∼10% of face velocity to prevent physically unreasonable solutions. The wall pressure extrapolation which is necessary for cell-centered FVM is another source of numerical errors. Some methods are applied in a unstructured FV solver and analyzed in view of numerical accuracy. Here, two natural convection problems are solved to check the effect of the Rhie-Chow's method on numerical stability. And numerical diffusion from Rhie-Chow's method is studied by solving the inviscid flow around a circular cylinder.