• Management & Information Systems Review
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• v.37 no.3
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• pp.27-47
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• 2018

In this study, we examine how land use zoning affects the land price controlling other variables such as road-facing condition of the land, land form, land age after its development and land size. We employ geographically weighted regression analysis which reflects spatial dependency as methodology with a data sample of land transaction price data of Jangyu, a new town, in Korea. The results of our empirical analysis show that the respective coefficients of traditional regression and geographically weighted regression are not significantly different. However, after calculating Moran's Index with residuals of both OLS and GWR models, we find that Moran's Index of GWR decreases around 26% compared to that of OLS model, thus improving the problem of spatial autoregression of residuals considerably. Unlike our expectation, though, in both traditional regression and geographically weighted regression where residential exclusive area is used as a reference variable, the dummy variable of the residential land for both housing and shops shows a negative sign. This may be because the residential land for both housing and shops is usually located in the level area while the residential exclusive area is located at the foot of a mountain or on a gentle hill where the residents can have good quality air and scenery. Although the utility of the residential land for both housing and shops is higher than its counterpart's since it has higher floor area ratio, amenity which can be explained as high quality of air and scenery in this study seems to have higher impact in purchase of land for housing. On the other hand, land for neighbourhood living facility seems to be valued higher than any other land zonings used in this research since it has much higher floor area ratio than the two land zonings above and can have a building with up to 5 stories constructed on it. With regard to road-facing condition, land buyers seem to prefer land which faces a medium-width road as expected. Land facing a wide-width road may have some disadvantage in that it can be exposed to noise and exhaust gas from cars and that entrance may not be easy due to the high speed traffic of the road. In contrast, land facing a narrow road can be free of noise or fume from cars and have privacy protected while it has some inconvenience in that entrance may be blocked by cars parked in both sides of the narrow road. Finally, land age variable shows a negative sign, which means that the price of land declines over time. This may be because decline of the land price of Jangyu was bigger than that of other regions in Gimhae where Jangyu, a new town, also belong, during the global financial crisis of 2008.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.449-460
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• 2013

This study analyzes the processes of change in oral health behaviors induced by oral health education for 23 university students. To this end, we analyzed the changing patterns of the stages of change and motivational components for each oral health behavior. Additionally, we performed an in-depth interview-based investigation of the factors influencing such motivational components. Oral health education was performed twice with a concrete purpose of changing the participants' behaviors in complying with the practice of proper brushing and flossing as the main oral health management, and checking the nutrient facts as a good dietary habit. Upon completion of these two sessions of oral health education, the level of change in oral health behavior was assessed by measuring the stages of change and motivational components for each oral health behavior. In order to gain an in-depth understanding of the reasons for the changes that were demonstrated more markedly during the second education session than during the first session, collective interview surveys were carried out after the second session. The contents of the recorded interviews were categorized into subscales of distinctive concepts on the basis of the items of a health behavior model. The study had the findings as below. First, after the first and second education sessions, some behaviors showed positive changes from lower to higher levels of practice. Second, self-efficacy about oral health behavior was high or perceived barriers were low when its necessity and benefits were clearly perceived. Third, educational features such as the practice and participation-centered education, and examining their own oral conditions influenced the participants' oral health awareness and behavioral changes. There is a need for oral health education capable of leading to practical behavioral changes by establishing concrete strategies of deriving various motivational components at each stage of the processes of change.

• Investigative Magnetic Resonance Imaging
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• v.7 no.2
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• pp.116-123
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• 2003

Purpose : The present study was undertaken to evaluate the usefulness of cerebral diffusion (DWI) and perfusion MR imaging (PWI) in rabbit models with hyperacute cerebral ischemic infarction. Materials and Methods : Experimental cerebral infarction were induced by direct injection of mixture of Histoacryl glue, lipiodol, and tungsten powder into the internal cerebral artery of 6 New-Zealand white rabbits, and they underwent conventional T1 and T2 weighted MR imaging, DWI, and PWI within 1 hour after the occlusion of internal cerebral artery. The PWI scan for each rabbit was obtained at the level of lateral ventricle and 1cm cranial to the basal ganglia. By postprocessing using special imaging software, perfusion images including cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps were obtained. The detection of infarcted lesion were evaluated on both perfusion maps and DWI. MTT difference time were measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. Results : In all rabbits, there was no abnormal signal intensity on T2WI. But on DWI, abnormal high signal intensity, suggesting cerebral infarction, were detected in all rabbits. PWI (rCBV, CBF and MTT map) also showed perfusion defect in all rabbits. In four rabbits, the calculated square of perfusion defect in MTT map is larger than that of CBF map and in two rabbits, the calculated size of perfusion defect in MTT map and CBF map is same. Any rabbits do not show larger perfusion defect on CBF map than MTT map. In comparison between CBF map and DWI, 3 rabbits show larger square of lesion on CBF map than on DWI. The others shows same square of lesion on both technique. The size of lesion shown in 6 MTT map were larger than DWI. In three cases, the size of lesion shown in CBF map is equal to DWI. But these were smaller than MTT map. The calculated square of lesion in CBF map, equal to that of DWI and smaller than MTT map was three. And in one case, the calculated square of perfusion defect in MTT map was largest, and that of DWI was smallest. Conclusion : DWI and PWI may be useful in diagnosing hyperacute cerebral ischemic infarction and in e-valuating the cerebral hemodynamics in the rabbits.

• The Korean Journal of Financial Management
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• v.21 no.2
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• pp.125-151
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• 2004

This study tests the price discovery from US Treasury bond markets to Korean bond markets using the daily returns of Korean bond data (CD, 3-year T-note, 5-year T-note, 5-year corporate note) and US treasury bond markets (3-month T-bill, 5-year T-note 10-year T-bond) from July 1, 1998 to December 31, 2003. For further research, we divide full data into two sub-samples on the basis of the start-up of bond valuation system in Korean bond market July 1, 2000, employing uni-variate AR(1)-GARCH(1,1)-M model. The main results are as follows. First the volatility spillover effects from US Treasury bond markets (3-month T-bill, 5-year T-note, 10-year T-bond) to Korean Treasury and Corporate bond markets (CD, 3-year T-note, 5-year T-note, 5-year corporate note) are significantly found at 1% confidence level. Second, the price discovery function from US bond markets to Korean bond markets in the sub-data of the pre-bond valuation system exists much stronger and more persistent than those of the post-bond valuation system. In particular, the role of 10-year T-bond compared with 3-month T-bill and 5-year T-note is outstanding. We imply these findings result from the international capital market integration which is accelerated by the broad opening of Korean capital market after 1997 Korean currency crisis and the development of telecommunication skill. In addition, these results are meaningful for bond investors who are in charge of capital asset pricing valuation, risk management, and international portfolio management.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.411-427
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• 2006

This study aimed to recognize characteristics of groundwater flow in fractured bedrocks based on zonal pump-ing tests, slug tests, water quality logs and borehole TV camera logs conducted on two boreholes (NJ-11 and SJ-8) in the city of Naju. Especially, the zonal pumping tests using sin91e Packer were executed to reveal groundwater flow characteristics in the fractured bedrocks with depth. On borehole NJ-11, the zonal pumping tests resulted in a flow dimension of 1.6 with a packer depth of 56.9 meters. It also resulted in lower flow dimensions as moving to shallower packer depths, reaching a flow dimension of 1 at a 24 meter packer depth. This fact indicates that uniform permissive fractures take place in deeper zones at the borehole. On borehole SJ-8, a flow dimension of 1.7 was determined at the deepest packer level (50 m). Next, a dimension of 1.8 was obtained at 32 meters of packer depth, and lastly a dimension of 1.4 at 19 meters of packer depth. The variation of flow dimension with different packer depths is interpreted by the variability of permissive fractures with depth. Zonal pumping tests led to the utilization of the Moench (1984) dual-porosity model because hydraulic characteristics in the test holes were most suitable to the fractured bedrocks. Water quality logs displayed a tendency to increase geothermal temperature, to increase pH and to decrease dissolved oxygen. In addition, there was an increasing tendency towards electrical conductance and a decreasing tendency towards dissolved oxygen at most fracture zones.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.4
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• pp.347-370
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• 2011

Slurry type shield would be very effective for the tunnelling in a sandy ground, when the slurry pressure would be properly adjusted. Low slurry pressure could cause a tunnel face failure or a ground settlement in front of the tunnel face. Thus, the stability of tunnel face could be maintained by applying an excess slurry pressure that is larger than the active earth pressure. However, the slurry pressure should increase properly because an excessively high slurry pressure could cause the slurry flow out or the passive failure of the frontal ground. It is possible to apply the high slurry pressure without passive failure if a horizontal impermeable layer is located in the ground in front of the tunnel face, but its location, size, and effects are not clearly known yet. In this research, two-dimensional model tests were carried out in order to find out the effect of a horizontal impermeable layer for the slurry shield tunnelling in a saturated sandy ground. In tests slurry pressure was increased until the slurry flowed out of the ground surface or the ground fails. Location and dimension of the impermeable layer were varied. As results, the maximum and the excess slurry pressure in sandy ground were linearly proportional to the cover depth. Larger slurry pressure could be applied to increase the stability of the tunnel face when the impermeable layer was located in the ground above the crown in front of the tunnel face. The most effective length of the impermeable grouting layer was 1.0 ~ 1.5D, and the location was 1.0D above the crown level. The safety factor could be suggested as the ratio of the maximum slurry pressure to the active earth pressure at the tunnel face. It could also be suggested that the slurry pressure in the magnitude of 3.5 ~4.0 times larger than the active earth pressure at the initial tunnel face could be applied if the impermeable layer was constructed at the optimal location.

• Journal of Korea Port Economic Association
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• v.32 no.3
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• pp.95-108
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• 2016

China has recently advocated a national strategy called "One Belt One Road" and transferred to execution to refine it into detailed action plans and has continued to fix the complement. However, the Korean Peninsula, including the North Korea remains could not be included at all in the Chinese development policy and framework in terms of the International Logistics. Currently it is raised between Korea-China rail ferry system again and that is when we need to make effective policy development on international multimodal transport system in Northeast Asia. This paper introduces the K-LB (Korea LandBridge) as its execution plan and conducted a feasibility study on this. K-LB consists of a Korea-Russian train ferry system based in Pohang Yeongil New Port(light-wing) and a Korea-China train ferry system based in Saemangeum New Port(left-wing). These two wings are linked to the existing rail system in Korea. This study is convinced that the K-LB is an effective international logistics system in the current terms and conditions and also demonstrated that it is feasible to introduce th K-LB on the peninsula. More strictly speaking, through a linear programming under objective function that minimize the transport cost quantified prior to demonstrate the feasibility, the available ranges and conditions for the transportation costs that are ensured the effectiveness of the K-LB are presented as results. According to the results, if the transport cost of K-LB is cheaper about 34.5% than that of sea transport such as container transport, the object goods may be transported by K-LB on this route. It means that the K-LB system has a competitive advantage due to more rapid customs clearance as well as omitted loading and unloading procedures over container transportation system. It also noted that the threshold level may not be large. Therefore, K-LB has competitive enough to prove its introduction in the Northeast Asian logistics system.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.4
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• pp.31-43
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• 2022

Startups are recognized as the vitality of the economy, and countries are competing to attract competitive overseas entrepreneurs and startups to their own startup ecosystem. In this global trend, entrepreneurs cross the border without hesitation, expecting abundant available resources and a startup friendly environment. Despite the increasing frequency of start-up migration between countries, studies related to this are very rare. Therefore, this study has chosen the cross-border migration of startups between countries as a research topic, and those who have been involved in the cross-border entrepreneurial migration to South Korea as a research sample. This study consists of two stages. The first research stage hires a Delphi method to collect expert opinions and find major factors related to the global startup migration. Drawing on the prior literature on the regional startup ecosystem at the national level, this stage is to conduct expert interviews in order to discover underlying factors and subfactors important for global migration of startups. The second stage measures the importance of the factors and subfactors using the AHP model. The priorities of factors and factors were identified hiring the overseas entrepreneurs who moved to Korea as the AHP survey samples. The results of this study suggest some interesting implications. First, a group of entrepreneurs with nomadic tendencies was found in the trend of global migration of entrepreneurs. They had already started their own businesses with the same business ideas in multiple countries before settling down in Korea. Second, important unique factors and subfactors in the context of global start-up migration were identified. A good example is the government's support package, including start-up visas. Third, it was possible to know the priority of the factors and subfactors that influence the global migration of startups This study is meaningful in that it preemptively conducted exploratory research focusing on a relatively new phenomenon of global startup migration, which recently catches attention in the global startup ecosystem. At the same time, it has a limitation in that it is difficult to generalize the meanings found in this study because the research was conducted based on the case of South Korea

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.3
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• pp.61-79
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• 2023

This study is a case study of overseas banana farms as a global agricultural startup that has hardly been attempted so far in terms of paradigm shift in the industry, beyond regional limitations. It was researched for the purpose of revealing the success factors of 'global agricultural startup' in terms of business process, entrepreneurship, and management dimensions learned through direct participation and observation at the local level. In order to study global agricultural startups, this study also conducted a comparative analysis of global startups (global startups) and global agricultural startups(global agricultural startups). In fact, the analysis consists of 'definition', 'components', and 'success factors', and we want to confirm the difference between the two concepts that can be distinguished. The case analysis tried to maximize the advantages of 'participatory action research' by directly observing and experiencing banana farms. In the case of banana farm cases, by dividing them into preparation process for farm development and farm development and management process, various variables considered in farm management were explained through the whole process of farm management. Through the process of overcoming and responding to specific failure cases, we tried to secure the reliability and validity of the research, and the case studies related to entrepreneurship, management, and organization analyzed by applying them by subdividing them into theoretical areas belonging to components and management that were theorized in existing preceding studies. This study is almost the first study on the process of creating a local entry business by directly moving the head office overseas rather than entering overseas agriculture as a subsidiary, joint venture or overseas corporation. In particular, it is a unique case that corresponds to agriculture in terms of region(Africa), scale(startup), and industry that have not been introduced so far as a global agricultural startup. In terms of entrepreneurship, it also concretely exemplified how entrepreneurship components such as innovativeness, risk-taking propensity, proactiveness, vision sharing, social contribution, leadership, etc., which have not been attempted so far in agricultural cases, are manifested and effective. The management and cultural aspects also went beyond the argument that only cultural aspects are important in overseas business, and also confirmed individual failure cases and their responses in recruitment, job, wage, retirement, development, organizational structure management, etc. As a result, there is significance and implications of this study in that it provides theoretical confirmation as well as practical and responsive basis for 'entrepreneurship', 'farming management', and 'management' aspects in overseas agricultural startup business operation.

• Clean Technology
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• v.30 no.1
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• pp.37-46
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• 2024

Environmental problems caused by plastic waste have been continuously growing around the world, and plastic waste is increasing even faster after COVID-19. In particular, PP and PE account for more than half of all plastic production, and the amount of waste from these two materials is at a serious level. As a result, researchers are searching for an alternative method to plastic recycling, and plastic pyrolysis is one such alternative. In this paper, a numerical study was conducted on the pyrolysis behavior of non-condensable gas to predict the chemical reaction behavior of the pyrolysis gas. Based on gas products estimated from preceding literature, the behavior of non-condensable gas was analyzed according to temperature and residence time. Numerical analysis showed that as the temperature and residence time increased, the production of H₂ and heavy hydrocarbons increased through the conversion of the non-condensable gas, and at the same time, the CH₄ and C₆H₆ species decreased by participating in the reaction. In addition, analysis of the production rate showed that the decomposition reaction of C₂H₄ was the dominant reaction for H₂ generation. Also, it was found that more H₂ was produced by PE with higher C₂H₄ contents. As a future work, an experiment is needed to confirm how to increase the conversion rate of H₂ and carbon in plastics through the various operating conditions derived from this study's numerical analysis results.