• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.433-442
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• 2021

This study analyzed the housing market before and after the New Stay movement which was introduced in 2015. In this study, the territories having a New Stay Project and non-involved territories were analyzed based on the apartment price changes according to supply for 12 months before and after the movement date. This study used the difference-in-differences statistical technique. A comparison was carried out in Michuhol-gu, Incheon between Dowha-dong where a New Stay Project was executed, and Sungeui-dong where no project was executed, based on the movement date. It was seen that the price level in the former territory was higher than the latter demonstrating that the introduction of the New Stay Project in Dowha-dong lowered the apartment prices nearby (Sungeui-dong). A comparison in Gwonseon-gu, Suwon between Omogcheon-dong where a New Stay Project was executed and Gosaek-dong where there was no such project, based on the movement date showed that the introduction of the New Stay Project in Omogcheon-dong seemed to lower or stabilize the apartment prices nearby (Gosaek-dong). These results imply that the apartment prices in nearby areas can be stabilized if the supply volume of company-type rental houses is increased.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.29-46
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• 2004

It is important to identify geometries of fracture that act as a conduit of fluid flow for characterization of ground water flow in fractured rock. Fracture geometries control hydraulic conductivity and stream lines in a rock mass. However, we have difficulties to acquire whole geometric data of fractures in a field scale because of discontinuous distribution of outcrops and impossibility of continuous collecting of subsurface data. Therefore, it is needed to develop a method to describe whole feature of a target fracture geometry. This study suggests a new approach to develop a method to characterize on the whole feature of a target fracture geometry based on the Fourier transform. After sampling of specimens along a target fracture from borehole cores, effective frequencies among roughness components were selected by the Fourier transform on each specimen. Then, the selected effective frequencies were averaged on each frequency. Because the averaged spectrum includes all the frequency profiles of each specimen, it shows the representative components of the fracture roughness of the target fracture. The inverse Fourier transform is conducted to reconstruct an averaged whole roughness feature after low pass filtering. The reconstructed roughness feature also shows the representative roughness of the target subsurface fracture including the geometrical characteristics of each specimen. It also means that overall roughness feature by scaling up of a fracture. In order to identify the characteristics of permeability coefficients along the target fracture, fracture models were constructed based on the reconstructed roughness feature. The computation of permeability coefficient was performed by the homogenization analysis that can calculate accurate permeability coefficients with full consideration of fracture geometry. The results show a range between $10^{-4}{\;}and{\;}10^{-3}{\;}cm/sec$, indicating reasonable values of permeability coefficient along a large fracture. This approach will be effectively applied to the analysis of permeability characteristics along a large fracture as well as identification of the whole feature of a fracture in a field scale.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.1-12
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• 2010

According to the capacity design concept which forms the basis of the current steel seismic codes, the braces in concentrically braced frames (CBFs) should dissipate seismic energy through cyclic tension yielding and cyclic compression buckling while the beams and the columns should remain elastic. Brace buckling in inverted V-braced frames induces unbalanced vertical forces which, in turn, impose the additional beam moments and column axial forces. However, due to difficulty in predicting the location of buckling stories, the most conservative approach implied in the design code is to estimate the column axial forces by adding all the unbalanced vertical forces in the upper stories. One alternative approach, less conservative and recommended by the current code, is to estimate the column axial forces based on the amplified seismic load expected at the mechanism-level response. Both are either too conservative or lacking technical foundation. In this paper, three combination rules for a rational estimation of the column axial forces were proposed. The idea central to the three methods is to detect the stories of high buckling potential based on pushover analysis and dynamic behavior. The unbalanced vertical forces in the stories detected as high buckling potential are summed in a linear manner while those in other stories are combined by following the SRSS(square root of sum of squares) rule. The accuracy and design advantage of the three methods were validated by comparing extensive inelastic dynamic analysis results. The mode-shape based method(MSBM), which is both simple and accurate, is recommended as the method of choice for practicing engineers among the three.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.556-566
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• 2014

In this study, we collected 29 Kenaf (Hibiscus cannabinus L.) genetic resources from 10 countries to confirm the possibility of the introduction into Korea. The Kenaf (Hibiscus cannabinus L.) has the broad industrial use like feed and the 5 times more strong $CO_2$ absorption capacity compared to general plant. So recently it is considered as a good industrial source. We analyzed ecotype, growth and development, yield and feed value of collected resources. They were divided into 3 groups depending on flowering time, early maturing type blooming in early July, mid-late maturing type blooming from end of August to early September and late maturing type blooming in end of October. Early maturing type could get fruitful seed but dropped yield (average 7,895 kg/10a) and late maturing type could get high yield (average 12,572 kg/10a) but deletion. The other side mid-late maturing type could get yield over a certain level (average 11,207 kg/10a) and fruitful seed was ensured. The yields analyzed by resources indicated that K12 (Hongma 300) collected in China, K25 from India, K22 from Russia and K21 (Khonkaen 60) variety from China were more than 13,500 kg per 10a. Feed value of early maturing type had inclined to more better than other types, but like dry digestible matter (DDM) and dry matter intake (DMI) of some late maturing types like K12, K21, K22 which had a high yielding ability were more better than that of early maturing types'. So relative feed value (RFV) which considered comprehensive item for feed value were indicated K21 was 102.5, K12 was 116.2 and K22 was 120.2. 'Jangdae' the variety developed in Korea which could complement of other types' had a good quality for yield 10,975 kg/10a and 12.5% crude protein content and 101.9 of the relative feed value. So we need to be taken power to collection of mid-late maturing types resources.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.399-403
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• 1997

Changes of nutrient material and natural supplies by sediment of irrigation water into 1.0ha of paddy field during the rice cultivation were investigated. TSS of the sediment contained irrigation water ranged 52.9${\sim}$125.6mg/L and content of organic matter showed 1.89${\sim}$2.33%. Content of T-N, $NH_4-N$ and $NO_3-N$ were 623.5${\sim}$1775.2, 22.9${\sim}$75.8 and 10.2${\sim}$72.1mg/kg respectively. Content of T-P and ortho-P were 186.7${\sim}$375.7 and 12.4${\sim}$38.9mg/kg respectively. The content of exchangeable canons, $Ca^{++},\;Mg^{++}\;Na^+\;and\;K^+$ were 435.3${\sim}$737.5, 127.3${\sim}$204.2, 36.6${\sim}$94.9 and 105.6${\sim}$232.9mg/kg respectively. Total content of heavy metals were 13.4 of Pb, 0.6 of Cd, 8.2 of Ni, 12.1 of Cu, 29.8 of Zn and 19.7mg/kg of Cr. During the period of rice cultivation, when supplied 4,250m^3 of an irrigation water into 1.0ha of paddy field, natural supplied 346.01kg of sediment, 7.11kg of organic matter, 0.50kg of T-N, 0.02㎏ of NH_4-N, 0.01kg of NO_3-N, 0.08kg of T-P and 0.01㎏ of Ortho-P. Also exchangeable $Ca^{++},\;Mg^{++}\;Na^+\;and\;K^+$ were supplied 0.21, 0.06, 0.02 and 0.06kg respectively. Loaded of the total heavy metal showed natural background level.

• Journal of Korea Port Economic Association
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• v.38 no.1
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• pp.1-14
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• 2022

The change in the management environment of the logistics industry in the era of global competition is becoming an era in which customers choose companies. Differentiation from competitors through the provision of products and services suitable for customers As customers' choices change depending on their superiority, companies are constantly striving to receive or retain customers' choices. Ultimately, this competitive structure can be seen as the importance of long-term relationship building. Therefore, in this study, we examined how factors related to transaction characteristics performed by logistics companies for customer satisfaction in the transaction relationship between cargo companies and shippers affect performance and long-term transaction intentions. First, we derived the factors of logistics service, cost, logistics infrastructure, and company competency, which are transaction characteristics factors of a logistics company that must be specifically realized for customer satisfaction in transactions between logistics companies. Second, we analyzed how the transaction characteristics factors of a logistics company affect the company's performance, and finally, how the company's performance factors affect long-term transaction intentions. As a result of empirical analysis, there were no statistically significant results on the relationship between transaction characteristics and performance of logistics companies, which can be attributed to the small size of the logistics companies that were the sample. In other words, logistics companies that do not have sufficient capacity to provide services at low prices have no choice but to engage in constant bleeding competition. It can be seen that it reflects the characteristics of the industry. On the other hand, the relationship between corporate performance factors and long-term transaction intention was found to have a positive relationship. The higher the level of partnership with logistics companies and visible financial performance is, the higher the transaction will be in the future, and the more the transaction volume will be gradually increased. And even if it costs a little more, it can be seen that the intention to continue trading is greatly expressed.