• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.595-603
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• 2019

To alleviate the demand on private car that is constantly increasing, Busan Metropolitan City (BMC) has established Bus Rapid Transit (BRT) to revitalize public transportation. But there are no unified lane system between BRT and general bus stations, which makes off-lane turning general bus to contribute to congestion. And as the bottleneck phenomenon at entrance/exit accelerates the congestion, there has been huge dissatisfaction among commuting drivers. Therefore, this study identifies efficient methods to operate better through measuring civilian awareness. We evaluate both satisfaction and drawbacks on BRT service with Importance-Performance Analysis (IPA). We first distinguish the groups by the awareness on BRT and their main transit usage, and then clarify the difference between the groups. And as a result, the group who is positive to BRT and uses buses often demands improvement in bus indoor comfort and curbing jaywalking. On the other hand, group who is negative to BRT and uses private cars often demands improvement in lane changing and the moving speed of private cars. We next examines the groups with MDPREF, one method of Multidimensional Scaling (MDS). And we have clarified that the evaluating criteria and the individual attributes of the groups corresponds very well.

• Journal of vocational education research
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• v.29 no.3
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• pp.265-289
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• 2010

This study aims to identify effects of outplacement support program for discharged soldier to settle and adapt successfully in Ministry of Patriots and Veterans Affairs. The subject of this study are 323 discharged soldiers who completed the outplacement support program. A survey questionnaire is conducted to measure variables of this study. All data analysis is accomplished using the AMOS 7.0 version. The results of this study are as follows. First, learning motivation has direct effect on learning flow and program satisfaction positively. Second, organizational support has direct effect on program satisfaction, psychological stability positively and on learning flow negatively. Third, outplacement support program has direct effect on learning flow, program satisfaction, job-seeking efficacy and psychological stability positively. Fourth, learning flow has direct effect on program satisfaction positively but don't have direct effect on job-seeking efficacy and psychological stability significantly. Fifth, learning motivation, outplacement support program has direct effect on job-seeking efficacy and psychological stability with partial mediation effect of program satisfaction while without mediation effect of learning flow. Based on the results of the study, the following recommendations have been made. First, it is necessary to design the outplacement support program with contents in relation to discharged soldiers' successful settlement because discharged soldiers who completed the outplacement support program showed higher job-seeking efficacy and psychological stability. Second, it is needed to conduct a longitudinal study considering other variables such as employment, establishment success etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.142-149
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• 2019

In this study, the past erosion history and current status in the CHUNG-UI beach of Eulwang-dong, Jung-gu, Incheon-Si, South Korea were investigated and analyzed the wave with wave-induced current to investigate the causes of coastal erosion. As a result, the significant wave height ($H_{1/3}$) was in the range of 0.07~1.57 m and the mean value was 0.21 m. The maximum wave height ($H_{max}$) was in the range of 0.02-4.76m and the mean value was 0.27m. The vertical wave height and cycles were estimated through numerical model experiments of wave transformation. The 50-year frequency design wave height ranged from 0.82m to 3.75m. As a result of the experiment of wave-induced current, wave-induced current in the CHUNG-UI beach was decreased after the installation of the Detached breakwater and the Jetty. On the other hand, when the crest elevation was increased up to 5 m, there was no significant change, but when the crest elevation was increased to 8m, strong wave-induced current occurred around the submerged breakwaters due to lowered depth of water. In addition, the main erosion of the CHUNG-UI beach is due to the intensive invasion of the wave characteristics coming from the outer sea into the white sandy beach. The deformation of the wave centered on the front of the sandy beach caused additional longshore currents flowing parallel to the sandy beach and rip currents in the transverse direction, thus confirming that the longshore sediment was moved out of the front and out of the sea. The results of this study can be used as preliminary data for the recovery of the sand and the selection of efficient erosion prevention facilities.

• The Journal of Korean society of community based occupational therapy
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• v.8 no.3
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• pp.77-89
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• 2018

Objective : The purpose of this study was to analyze occupational therapy intervention on the community mobility for stroke patients, and to provide evidence of intervention in the clinical fields. Methods : A systematic review was executed according to the PRISMA checklist. The accessed database was PubMed, EMBASE, Cochrane Library (CENTRAL), ProQuest Dissertations & thesis (PQDT), RISS, and KoreaMed. We included the articles published from 2005 to September 2018. RoBANS checklist was used to evaluate the quality of the articles. Included articles, totally eight, were categorized according to the type of intervention. Results : The study design of the literature was varied from two-group randomized trial, quasi-experimental study, case-control trial, one group pre-post comparison study, and cross-sectional study. In the evidence level, 6 articles were included in level II (75%). The percentage of low risk of bias in each article ranged from 52.5%~87.5%. Four studies (50%) provided intervention based on virtual reality or virtual environment. The three (37.5%) provided intervention based on the protocol, and the other (12.5%) did wheelchair training. All studies reported significant effects of the intervention. Conclusion : This systematic review provided evidences to use proper intervention in the clinical fields. Various type of studies should be conducted to prove the effect of occupational therapy intervention for community mobility.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.178-188
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• 2019

When using a distributed system, it is very important to know the intention of a target ship in order to prevent collisions. The action taken by a certain ship for collision avoidance and the action of the target ship it intends to avoid influence each other. However, it is difficult to establish a collision avoidance plan in consideration of multiple-ship situations for this reason. To solve this problem, a Distributed Stochastic Search Algorithm (DSSA) has been proposed. A DSSA searches for a course that can most reduce cost through repeated information exchange with target ships, and then indicates whether the current course should be maintained or a new course should be chosen according to probability and constraints. However, it has not been proven how the parameters used in DSSA affect collision avoidance actions. Therefore, in this paper, I have investigated the effect of the parameters and weight factors of DSSA. Experiments were conducted by combining parameters (time window, safe domain, detection range) and weight factors for encounters of two ships in head-on, crossing, and overtaking situations. A total of 24,000 experiments were conducted: 8,000 iterations for each situation. As a result, no collision occurred in any experiment conducted using DSSA. Costs have been shown to increase if a ship gives a large weight to its destination, i.e., takes selfish behavior. The more lasting the expected position of the target ship, the smaller the sailing distance and the number of message exchanges. The larger the detection range, the safer the interaction.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.102-116
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• 2021

For the safe operation of autonomous vehicles, the representative technology of the 4^th industrial revolution era, a combination of various technologies such as sensor technology, software technology and car technology is required. An autonomous vehicle is a vehicle that recognizes current location and situation by using the various sensors, and makes its own decisions without depending on the driver. Perfect recognition technology is required for fully autonomous driving. Since the precise road maps provide various road information including lanes, stop lines, traffic lights and crosswalks, it is possible to minimize the cognitive errors that occur in autonomous vehicles by using the precise road maps with location information of the road facilities. In this study, the definition, necessity and technical trends of the precise road map have been analyzed, and the HD(High Definition) map prototype based on the web GIS has been built in the autonomous driving-specialized areas of Daegu Metropolitan City(Suseong Medical District, about 24km), the Happy City of Sejong Special Self-Governing City(about 33km), and the FMTC(Future Mobility Technical Center) PG(Proving Ground) of Seoul National University Siheung Campus using the MMS(Mobile Mapping System) surveying results given by the National Geographic Information Institute. In future research, the built-in precise road map service will be installed in the autonomous vehicles and control systems to verify the real-time locations and its location correction algorithm.

• Journal of Korean Society of Forest Science
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• v.110 no.1
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• pp.64-71
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• 2021

Recently, climate change has gradually accelerated the occurrence of landslides. Among the various effects caused by landslides,debris flow is recognized as particularly threatening because of its high speed and propagating distance. In this study, the impacts of various factors were analyzed using quantification theory(I) for the prediction of debris flow hazard soil volume in Seoraksan National Park, Korea. According to the range using the stepwise regression analysis, the order of impact factors was as follows: vertical slope (0.9676), cross slope (0.6876), altitude (0.2356), slope gradient (0.1590), and aspect (0.1364). The extent of the normalized score using the five-factor categories was 0 to 2.1864, with the median score being 1.0932. The prediction criteria for debris flow occurrence based on the normalized score were divided into four grades: class I, >1.6399; class II, 1.0932-1.6398; class III, 0.5466-1.0931; and class IV, <0.5465. Predictions of debris flow occurrence appeared to be relatively accurate (86.3%) for classes I and II. Therefore, the prediction criteria for debris flow will be useful for judging the dangerousness of slopes.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.6
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• pp.43-54
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• 2020

This paper investigates the causal impact of the increase in institutional distance between two geographic regions on the flow of cross-border Venture Capital (VC) between the regions. While cross-border VCs are believed to have competitive advantages at identifying and managing promising startups in a local market compared to local counterparts, the discrepancy in institutional characteristics between two markets exacerbates the difficulty of credible information exchange and negotiation, significantly increasing transaction cost related to a cross-border venture capital investment. This study conducts a difference-in-difference analysis to examine the relationship between institutional distance and the flow of cross-border VC investment using the fact that the official adoption of the Euro currency by member countries of the European Union except the UK created an institutional chasm between the UK and other EU member countries. The outcomes of the analysis suggests that UK-based VCs significantly decreased the VC investment into EU-based startups and that EU-based VCs reduced the investment into UK-based startups. The results have meaningful implications for understanding the impact of the change in institutional difference on cross-border VC investment, which seems to increasingly take place with the recent trend of de-globalization and the rise of protectionism.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.21-32
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• 2023

Interrill erosion dominates in forest areas, and the erosion rate in surface-disturbed areas is significantly increased by the development and expansion of rill. In this study, soil erosion experiments using simulated rainfall and inflow were performed to understand the development and the micromorphological changes of rill on steep slopes. The characteristic factors of the micromorphology, such as the rill cross section, rill volume, rill density, rill order, and rill sharpness, were analyzed according to steepness and location (upper or lower) of slope. The head-cut of the simultaneous incised rills by rainfall simulation moved rapidly upslope, and the randomly developed rills expanded deeply and widely with their connection. The rill cross section evolved to downslope gradually increased. The rill volume occupied about 78 % of the sediment volume, confirming that the contribution of the sediment from the rill erosion is greater than that of the interrill erosion. Although the rate of increase in rill order slowed as the slope increased, the total length and density of the rill generally increased. As the slope increased from 15° to 20°, the bed incision of rills became larger than the sidewall expansion, and the rill sharpness increased by 1.6 times. The runoff coefficient on the lower slope decreased by 12.3 % than that on the upper slope. It was evaluated that the subsoil exposures and formation changes by the rill expansion increased the infiltration rate. Although the sediment accompanying the rills generally increased with slope increase, it was directly influenced by the hydraulic velocity of enhanced rill with the local convergence and expansion in the process of the rill evolution.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.121-131
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• 2023

The Chinese three northeastern three provinces - Heilongjiang, Liaoning, and Jilin - hold significant geographical, geopolitical, and commercial importance due to their location allowing for cross-border trade and transportation with North Korea. These provinces are crucial for establishing a complex Eurasian logistics network in line with South Korea's new northern policy. The Chinese three northeastern three provinces, as this region is known, boasts excellent maritime transportation links between South Korea, China, and North Korea, making it an logistics hub for transporting goods to Eurasia and Europe through multimodal transport. This study highlights the importance of securing a logistics hub area by fostering cooperation and friendly relations with China's three northeastern three provinces, which are crucial to the success of the New Northern Policy. In particular, the study aims to analyze current status of trade with these region and freight volume transported by ships and recommend political advice for securing logistics hub and revitalizing maritime transport. As the policy suggestion, this study is to establish a logistics hub by implementing joint port operations, constructing port infrastructure jointly, and operating shipping companies together. Additionally, we propose ways to revitalize the maritime passenger transport business between Korea and China, which involves expanding cultural exchanges and developing content.