• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.5
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• pp.20-27
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• 2001

The purpose of this study is to investigate and compare the validity and the reliability of the visual simulation method using the internet. For this. the evaluation of the artificial and natural landscape through the medium of color slides are compared with the internet survey. Data is analysed through the comparison of t-test between the two media by landscape type, and spatial image is analysed by factor analysis algorithm. Principle component analysis using Varimax Method is applied for extraction and factor rotation respectively. The results of this study can be summarized as follows; There are no statistical differences between the two methods with artificial and natural landscape in the total data that included second tests. Factors covering the spatial image are found to be \`aesthetic\`, \`spatial shape\`, and \`familiarity\`. Total variance is obtained as 66.4%. There are no statistical differences between the two methods in 2/3 of the cases. In the case of far view of artificial landscape, the results of the t-test show that the two methods are exactly the same. Especially in the case of the artificial far landscape shows no difference of all factors between two methods. There are no differences between first and second tests of the same media and the same landscape type. And it shows the reliability of this method. These results suggest that the probability that the internet can be used as a medium of landscape evaluation and gathering information on anyone\`s landscape image. Simulation techniques with the internet survey method should be further developed for practical application.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.740-748
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• 1998

The inertia friction properties of C/C composites manufactured by the processes of pressure and at-mospheric carbonizaton with a commerciallized and two kinds of modified coal-tar pitch as a matrix pre-cursor were investigated. The modifications of a pitch such as the introduction of mesophase and the ad-dition of sulphur into a raw pitch were not effective for a impregnation efficiency conducted in a vacuum and at the same time in a pressure of 5kg/cm2 due to the increase of the pitch viscosity. There was not a difference in the densification increment between the pitch modifications however it was revealed that a pressure carbonization was more advantageous than an atmospheric in the densification and the formation of anisotropic carbon matrix. The friction and wear propertis of C/C having higher degree of matrix cry-stallization higher density and hardness of friction surface showed superiority. As the braking energy was increased the friction coefficients were decreased and reached almost same level at the high kinetic energy of 99.6kJ. The wear trends at 99.6kJ were different from the behaviors of friction ceofficient under the same energy in which an oxidation wear is being considered along with a mechnical wear although the wear rates were almost similar to the friction coefficient at the low energy.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.167-176
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• 2006

In this paper we show that solutions of the nonlinear Nernst-Planck equation possesses the quadruple-layer structure near the interface when the electrolyte receives a high frequency forcing such as a high-frequency alternating current. Very near to the interface wall, the well-known, classical Stern layer exists. Near to the Stern layer we have the secondly thin layer (to be called inner layer in this paper) where the ion concentrations behave under the same frequency as the external forcing. However, in this layer, the positive and negative ion concentrations develop with the time phase 180-degree different from each other. Next to this second layer, we have the third layer (called middle layer) in which two ion concentrations change with the time period double the forcing, and both concentrations behave in the same time phase. In the outermost layer, i.e. the forth layer, (called outer layer) the ion concentrations show the same-phase development as the third one but decaying very slowly in time. Our assertion is mostly based on the 1-D numerical simulation for the Nernst-Planck equation under a high frequency AC field assuming that the quadruple layer is very thin compared with the length scale representative of the bulk region.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.339-343
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• 1997

To investigate the possibility of making noodle with Chestnuts flour(C.F), it was mixed with wheat flour by the ratio of 70%. Making characteristics of noodle was studied in terms of the viscosity property, cooking quality test, color measurement and sensory evaluation. The viscosity property of noodles with 10~20% C.F was almost same value as control. In the cooking quality test, noodles with 10~30% C.F was almost same value as control in weight, volume and absorbance of cooked noodle. Color difference($\Delta$E) between noodles with C.F was not significantly different from control in color, only noodle with 10% C.F was same as control in texture by sensory evaluation test. Based on the cooking and sensory evaluation test, addition of 30% C.F to wheat flour may be suitable for making noodle.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.113-118
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• 2009

Grounding systems set the reference voltage level of electric circuits and suppress the Ground Potential Rise (GPR) by flowing fault currents to the ground safely. There are several parameters which evaluate the performance of grounding systems as ground resistance, touch voltage and step voltage. The touch and step voltages, which is called "risk voltage", are especially important to ensure the safety of human body. This paper dealt with the influence of current sources with the different frequency components on the touch and the step voltages. Three types of current sources as commercial frequency, square wave, and surge with the fast risetime of $50\;ns{\sim}500\;ns$ were used to analyze the risk voltages in a grounding system. The risk voltages showed remarkable difference in the same current amplitude depending on the current sources, and increased linearly with the current amplitude in the same current source. From the experimental results, it was confirmed that the risk voltages can be evaluated by a small current application in large-scale grounding systems and the possible largest risk voltage can be calculated by a surge current with the risetime of 200 ns or a current source with the same frequency component as the surge current.

• Journal of the Korean Society of Costume
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• v.15
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• pp.21-45
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• 1990

The purpose of this thesis is to study the method of the reasonable pattern design. The studying method is based on the original principle of the trousers' cutting and I have a hypothesis about the trousers pattern which should be proved. When I selected the practical method, I made use of the international measuring rule, graph paper and tracing paper, in order to prove the new pattern design. The reasonable pattern design should be the one of the suitable original principles to be suited in the design through any measurement. Therefore, I have discussed the above mentioned design. I find out the conclusion to prove the hypothesis of pattern design with the experimental measure after showing the above mentiond design. The characteristics is as follows. First : To be convinient when walking, because of little degree as folding of the front part of trousers with the under-angle. Second : To be suitable in proportion to the length of trousers and the under-angle. Third ; When folding the center line of the Sapok (a name of one of the trousers parts), the length of the Sapoks is same and harmonized with the Sapoks because of the same angle of both Sapoks in any case of the measurement. Fourth : No correction of the lines when dressing, for the same points of the large Sapok and the small one. Fifth : To be easiness of the pattern design through the concrete measurement. I could find out a little extent errors of pattern showings, an easiness of dressing, scientification of formation in Korean trousers and standard of the practical measurement in the program to be presented as the result of studying.

• Computers and Concrete
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• v.21 no.5
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• pp.583-592
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• 2018

Today, buildings are exposed to the effects such as explosion and impact loads. Usually, explosion and impact loads that act on the buildings such as nuclear power plants, airports, defense industry and military facilities, can occur occasionally on the normal buildings because of some reasons like drop weight impacts, natural gas system explosions, and terrorist attacks. Therefore, it has become important to examine the behavior of reinforced concrete (RC) structures under impact loading. Development of computational mechanics has facilitated the modeling of such load conditions. In this study, three kinds of RC walls that have different geometric forms (square, ellipse, and circle) and used in guardhouses with same usage area were modeled with Abaqus finite element software. The three configurations were subjected to the same impact energy to determine the geometric form that gives the best behavior under the impact loading. As a result of the analyses, the transverse impact forces and failure modes of RC walls under impact loading were obtained. Circular formed (CF) reinforced concrete wall which has same impact resistance in each direction had more advantages. Nonetheless, in the case of the impact loading occurring in the major axis direction of the ellipse (EF-1), the elliptical formed reinforced concrete wall has higher impact resistance.

• Journal of Auto-vehicle Safety Association
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• v.9 no.3
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• pp.7-12
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• 2017

The whiplash is the most important issue of low speed rear-impact. So auto makers are committed to developing a seat to improve whiplash injury. Most NCAP tests have been used by same pulse (Mid Velocity 16kph). Only Euro NCAP uses different pulse that consists of Low, Mid, High velocity. But Euro NCAP also uses same pulse in Mid velocity as other NCAP test. That Mid velocity NCAP pulse was made by rear impact that has 90's vehicle structure properties. That pulse was used until now days. However these days, auto maker use more high tensile steel than 90's as customer and society demand more fuel efficiency and light vehicle with good safety structure. So modern vehicles have different pulse patterns of rear impact than NCAP pulse and 90's vehicle crash properties. In this paper, the test was conducted by following condition. Target car was impacted by the rigid barrier with certain velocity. Finally target vehicle gained delta V 16kph which was same velocity as NCAP Mid Velocity pulse. It is critical velocity which occur long period neck injury. It is very different pulse that was gained by real car impact from NCAP pulse. And it has higher peak G with high fluctuation and short duration than NCAP pulse.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.6
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• pp.784-789
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• 2004

The purpose of this research was to analyze how the evaluation method affects the subjective hand evaluation of fabrics and to suggest the efficient evaluation method. Three methods such as the sense of sight ＆ touch, the sense of touch, and the sense of sight were respectively used when judges estimated the hand of fabrics using questionnaire. The result obtained by the method of touch was same as that by the method of sight ＆ touch. The time required for the evaluation by these two methods was statistically same. Consequently, the method of touch has no attraction compared to that of touch ＆ sight. In case of using the method of sight, 8 properties among 10 showed the same results as in the method of sight ＆ touch. The properties of [moogupda/kabyupda] and [shinchuksung-e-itda/ shinchuksung-e-upda] evaluated with the sense of sight were different from the results obtained by the other methods. These properties seem to be difficult to evaluate only by seeing the fabric on the table. For the precise evaluation, it is necessary to show dynamic movement of the fabric. The time required for the evaluation by the sense of sight was shorter than that by the other two methods.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.555-561
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• 2008

In air stripping of ammonia from the aqueous solution, a new removal model was presented considering the equilibrium principles for the ammonia in aqueous solution and between the aqueous and air phase. The effects of pH, temperature and airflow rate on the ammonia removal were evaluated with the model. In addition, the saturation degree of ammonia in air was defined and used to evaluate the effect of each experimental factor on the removal rate. As pH (8.9 to 11.9) or temperature (20 to 50 oC) was increased, the overall removal rate constants in all cases were appeared to be increased. Our presented model shows that the degrees of saturation were about the same (0.45) in all cases when the airflow condition remains the same. This result indicates that the effect of pH and temperature were directly taken into consideration in the model equation. As the airflow increases, the overall removal rate constants were increased in all cases as expected. However, the saturation degree was exponentially decreased with increasing the airflow rate in the air phase (or above-surface) aeration. In the subsurface aeration the saturation degree remains a constant value of 0.65 even though the airflow rate was increased. These results indicate that the degree of saturation is affected mainly by the turbulence of the aqueous solution and remains the same above a certain airflow rate.