• KIEAE Journal
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• v.5 no.1
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• pp.43-49
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• 2005

People grow up and build up most of their character through living in dwelling space and have relax and refresh at home. Creating healthy dwelling space is being considered very important in architectural planning and design for providing comfortable living environment and improving quality of life. One of the properties of the earth is that the earth has a magnetic field associated with it- the Geomagnetic field. The geomagnetic field is produced by a combination of crustal rocks, external electric current systems that surround the earth that surround the earth and currents induced in the outer layers of the earth by magnetic field variations. Human beings have evolved with the background of magnetic field, they are accustomed to living in its presence. Geopathic stress occurs at geopathic zones where the geomagnetic field is disturbed. Geopathic zones exhibit magnetic charges. Geopathic zones are characterized by variations in geomagnetism, for the geomagnetic field is not uniform but exhibits many highly localized distortions, some random, some fairly regular. These occur in geological faults, caves and underground water channel. Many research papers and experiments of the western countries indicates that the geomagnetic field affects the people and living organism in dwellings. Therefore, it is necessary to investigate the geomagnetic field and people's response in living space. In this study the Health Hazard of geomagneic field in dwelling are studied through literature survey of related science field.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.646-651
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• 2002

The flow field around a symmetrical airfoil in a uniform flow under the generation of noise was studied by experiments and numerical simulation. The experiments are conducted by visualizing the surface flow over the airfoil with a shear-sensitive liquid-crystal coating and by measuring the instantaneous velocity field around the trailing edge of the airfoil. The results indicate that the discrete frequency noise is generated when the separated laminar flow reattaches near the trailing edge of the pressure side and the turbulent boundary layer is formed over the suction side of the airfoil near the trailing edge. The periodic behavior of vortex formation was observed around the trailing edge and it persists further downstream in the wake. The frequency of the vortex formation in the wake was consistent with that of the discrete frequency noise.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1053-1062
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• 1993

The effect of loading speed on soil failure was studied by using a high speed triaxial compression test. Tests were conducted at 0.35-6.2m/s loading speed to compress soil specimens of sandy loam at different moisture contents. The axial stress at fracture increased with increase in loading speed up to certain critical speeds, however they decreased as the speed up to certain critical speeds, however they decreased as the speed increased further. Experiments were also conducted in the field of sandy loam soil with the vibrating tillage tool. Tests were done at 0.33-0.85m/s tractor speed oscillating frequency 13.7hz and oscillating amplitude 59mm. The maximum oscillating velocity of tillage tool was 2.5m/s. It was observed that for the oscillating operation, initially draft slightly increased with increase in forward speed and then it decreased .For the non-oscillating operation, draft increased continuously with increase in forward speed. Approach of studying soil failure in the laboratory test can be related to the field experiments.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.1
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• pp.15-26
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• 2007

This study analyzes revenue-maximizing strategies of online auction sellers in terms of setting up starting bids and buy-it-now options. To this end, a series of field experiments is conducted where women's hair accessories of unique designs are listed in an established online auction site. The results of the experiments argue that high starting bids could increase sellers' revenue while buy-it-now options have no significant effects. Our findings suggest that online auction sellers listing items with uncertain demand - mainly individual sellers - should be cautious with auction tips which generally support low starting buds.

• Journal of Haehwa Medicine
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• v.20 no.1
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• pp.175-182
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• 2011

This study aims to summarize and make a reference of Sagunjatang and Samultang by investigating and comparing the effects of prescriptions. In this process, this review surveyed all papers used Sagunjatang and Samultang in PubMed database and finally 36 papers were included. The publication year, the nations of authors, the type of materials, the formation of experiments, the type of herbal medicine, and their action and mechanisms were analyzed. The number of studies on Sagjunjatang and Samultang has increased since 1990's. The main formation of experiments was in vivo study and the portion was 55%. The proportion of the research using prescriptions was 71%. Sagunjatang was investigated in the field of GI track function, anticancer effect, radioprotective effect and etc. Samultang was studied in the field of anticancer effect, brain cognitive function, anti-inflammatory effect, cell protective effect, and etc. Based on these results, Sagunjatang and Samultang showed the different bioactivities. This study will provide the useful information on differentiation and analysis of the effect of herbal prescriptions by the theory of Korean traditional medicine.

• Transactions of Materials Processing
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• v.6 no.3
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• pp.203-212
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• 1997

In this research, to obtain the optimal die width of CV die(conventional die), which replaces FM die in free forging of large scale rotor using the flat die, the model material experiments and theoretical analysis using three dimensional FEM are performed. The FM die, which was designed to remove Mannesmann's effect at the central part of the ingot, has very bad workabiltity in real field, therefore on the empirical base they use the CV die of wide width in actual working field. In this study, the excellency of CV die is proved quantitively, and the optimal die width of CV die is determined through the model material experiments and theoretical analysis using FEM in the point of effective strain, stresses, and load.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.65-68
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• 2003

A quantitative study of the amount of air transported between the boundary layer and the free atmosphere is important for understanding air quality and upper tropospheric ozone, which is a greenhouse gas. Frontal systems are known to be an effective mechanism for the vertical transport of pollutants. Numerical experiments have been performed with a simple two-dimensional front model to simulate vertical transport of trace gases within developing cold fronts. Three different trace gases experiments have been done numerically according to the different initial fields of trace gases such as aerosol, ozone and $H_2O_2$. Trace gas field tilts to the east while the front tilts to the west. Aerosol simulation shows that pollutants can be transported out of the boundary to altitudes of about 10 km. The stratospheric ozone is brought downwards in a tropopause fold behind of the frontal surface. The meridional gradient in trace gas ($H_2O_2$) can cause a complicate structure in the trace field by the meridional advection.

• Journal of the Korean Society of Industry Convergence
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• v.9 no.3
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• pp.199-206
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• 2006

Extraordinary displacement and vibration by heavy vehicle causes passengers to feel mental uncomfortableness and bridge to be damaged. To increase serviceability, the research on the human influence for vibration to happen at the bridge has been performed for a long time in oversea but it does not draw concern relatively in the domestic. The purpose of this research is to develop an evaluation method for vibration serviceability of continuous slab bridge. This research is focused on establishing theoretical method to assess vibration serviceability of bridge considering natural frequency, displacement, and acceleration since the criteria for the human responses to vibration is generally based on frequency band. By examining the characteristics of vibration serviceability which has been assessed with human response curve through field experiments as well as analytical study, the evaluation method of vibration serviceability for continuous slab bridges is proposed. Based on applications to the example of continuous slab bridge, the simple evaluation of vibration serviceability in the paper may be used in the initial step of design practice.

• Journal of The Korean Astronomical Society
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• v.37 no.4
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• pp.237-241
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• 2004

We perform numerical experiments on supernova-driven turbulent flows in order to see whether or not supernovae playa major role in driving turbulence in the interstellar medium. In a $(200pc)^3$ computational box, we set up, as initial conditions, uniformly magnetized gas distributions with different pairs of hydrogen number densities and magnetic field strengths, which cover the observed values in the Galactic midplane. We then explode supernovae at randomly chosen positions at a Galactic explosion rate and follow up the evolution of the supernova-driven turbulent flows by integrating numerically the ideal MHD equations with cooling and heating terms. From the numerical experiments we find that the density-weighted velocity dispersions of the flows are in the range of 5-10 km $s^{-l}$, which are consistent with the observed velocity dispersions of cold and warm neutral media. Additionally, we find that strong compressible flows driven by supernova explosions quickly change into solenoidal flows.

• The Korean Journal of Applied Statistics
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• v.1 no.1
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• pp.21-28
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• 1987

In agricultural research field experiments are usually conducted with the sam etreatments in the same experimental design over several locations for several years in order to draw widely adaptable results. For generalization of the results from the individual locations and the properties of the treatment responses may be evaluated by carrying out the combined analysis over agricultural climate zones or country level. A method of combined analysis of variance was presented and examined by applying to a set of data obtained from a series of rice variety adaptability trials conducted by Kyung Buk Provincial Office of Rural Developmention 1986.