• Journal of the Economic Geographical Society of Korea
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• v.14 no.2
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• pp.116-128
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• 2011

Some subway passengers may want to have their fresh vegetables purchased through internet at a service facility within the subway station of the Metropolitan Seoul subway system on the way to home, which raises further questions about which stations are chosen to locate service facilities and how many passengers can use the facilities. This problem is well known as the pickup problem, and it can be solved on a traffic network with traffic flows which should be identified from origin stations to destination stations. Since flows of the subway passengers can be found from the smart card transaction database of the Metropolitan Seoul smart card system, the pickup problem in the Metropolitan Seoul subway system is to select subway stations for the service facilities such that captured passenger flows are maximized. In this paper, we have formulated a model of the pickup problem on the Metropolitan Seoul subway system with subway passenger flows, and have proposed a fast heuristic algorithm to select pickup stations which can capture the most passenger flows in each step from an origin-destination matrix which represents the passenger flows. We have applied the heuristic algorithm to select the pickup stations from a large volume of traffic network, the Metropolitan Seoul subway system, with about 400 subway stations and five millions passenger transactions daily. We have obtained not only the experimental results in fast response time, but also displayed the top 10 pickup stations in a subway guide map. In addition, we have shown that the resulting solution is nearly optimal by a few more supplementary experiments.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.274-281
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• 2015

Thermal and nuclear power plants on shore commonly use the sea water for cooling facility. Discharged cooling water has the high kinematic energy potential due to amount of water flux. Numerical analysis was made to find the suitable combinations between the arrangement of tidal turbines and the overall dimensions of the discharged channel. Several parameters such as the turbine diameter to inlet size, and the axial distance to turbine size were investigated. Power coefficients for various test conditions were also compared to see the effect of inlet configurations such as single inlet and dual inlet. For the single inlet, the mean power coefficient appeared to be gradually decreased with increasing distance, and the maximum power was obtained when the turbine diameter was same as the inlet diameter. For the dual inlet, the tendency was similar so that the better result when the turbine diameter was same as the inlet diameter. It is expected that the present methodology can be extensively utilized to harness the high kinetic energy flow of the discharge channel of power plant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.333-344
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• 2017

This research analyzes Seoul station, a typical transfer station complex, focusing on the evaluation of its barrier free design suitable for vulnerable persons such as senior citizens. The analysis was conducted to assess its compliance with the "barrier-free" design standard for those with physical or other disabilities. This paper proposes a list of items to evaluate for transfer station complexes with a barrier-free design. The results showed that the overall connections and internal and sanitation facilities of (Seoul station/the design?)were excellent. However, because of the lack of transfer and guidance facilities, vulnerable persons felt uncomfortable when searching for information about transferring from one means of transport to another. Furthermore, there was an extremely high risk of accidents when they transferred to the bus station. Therefore, it is necessary to arrange the transfer information facilities, in order to improve their readability and visibility. Once this is done, vulnerable people will be able to use this station more safely and conveniently.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.3 s.30
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• pp.69-78
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• 2004

Since 1995, One of the NGIS(National Geographic Information System) projects, the underground utilities project, has been finished in 2003. The 19 cities in korea for this project will use underground utilities management system using underground utilities database focusing on water and sewage system. However, special expert, technical and experience problem in computer environment has not been had in working department for water and sewage management and maintenance for each local government. The management and maintenance by underground utilities database by manual method is getting lowered a data qualify of underground utilities database because of the data omitting, error in writing and securing of the lasted database. Therefore, in this study, Application test for field workers using a mobile tool and environment analysis of wireless communication in Korea and application test of GPS receiver for mobile tools had been processed and made a mobile working environment. The efficient management and maintenance method for underground utilities database has been developed an off-line method for modification and update of database about general work which has a high working frequency because of the limitation of wireless communication environment. Also, the emergency working has been applied for on-line method.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.11
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• pp.820-829
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• 2006

Wireless sensor networks consisting of hundreds to thousands of nodes are expected to be increasingly deployed in coming years, as they enable reliable monitoring and analysis of physical worlds. These networks have unique features that are very different from traditional networks, e.g., the numerous numbers of nodes, limitation in power, processing, and memory. Due to these unique features of wireless sensor networks, sensor data management including querying becomes a challenging problem. Furthermore, due to wide popularization of the Internet and its facility in use, it is generally accepted that an unattended network can be efficiently managed and monitored over the Internet. In particular, in order to more efficiently query and manage data in a sensor network. in this paper, the architecture of a sensor gateway including web-based query server is presented and its implementation detail is illustrated. The presented web-based gateway is largely divided into two important parts: Internet part and sensor network part. The sensor network part plays an important role of handling a variety of sensor networks, including flat or hierarchical network architecture, by using internally layered architecture for efficiently querying and managing data in a sensor network. In addition, the Internet part provides a modular gateway function for favorable exchange between the sensor network and Internet.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.768-774
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• 2010

A parametric study is conducted for the segmented arc plasma torch with the input power and current of 0.4 MW and 300 A, respectively. For this purpose, we use the analytical relationship equations between plasma temperature, inner diameter (R) and length (L) of the torch constrictor at the given input power and current conditions based on the arc channel model. The results reveal that arc plasma temperatures show non-linear behavior or absence corresponding to the variations of L and R when their values become larger than 1.25 m and 7.5 mm, respectively. For L < 1.25 m and R < 7.5 mm, however, they can increase monotonically as L increase or R decrease when one of both parameters is fixed. From these parametric study results, optimum ranges of R and L are suggested as $5.5mm{\leq}R{\leq}7.0mm$ and $0.5m{\leq}L{\leq}1.0m$ for 0.4 MW class segmented arc plasma torch, under which stable arc plasma with the temperatures of ~15,000 K can be achived at the input currents of ~300 A.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.103-113
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• 2019

License plate recognition camera is dedicated device designed for acquiring images of the target vehicle for recognizing letters and numbers in a license plate. Mostly, it is used as a part of the system combined with server and image analysis module rather than as a single use. However, building a system for vehicle license plate recognition is costly because it is required to construct a facility with a server providing the management and analysis of the captured images and an image analysis module providing the extraction of numbers and characters and recognition of the vehicle's plate. In this study, we would like to develop an embedded type convergent camera (Edge Base) which can expand the function of the camera to not only the license plate recognition but also the security CCTV function together and to perform two functions within the camera. This embedded type convergence camera equipped with a high resolution 4K IP camera for clear image acquisition and fast data transmission extracted license plate area by applying YOLO, a deep learning software for multi object recognition based on open source neural network algorithm and detected number and characters of the plate and verified the detection accuracy and recognition accuracy and confirmed that this camera can perform CCTV security function and vehicle number plate recognition function successfully.

• 한국노년학
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• v.37 no.3
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• pp.583-600
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• 2017

The purpose of this study is to explore qualitatively what kind of coping strategy the Korean older adults use when they are depressed and why. Participants were users, older than 60, of an elderly welfare center in Seoul, and answers of 34 respondents who experienced depression were included in the analysis. The collected data were analyzed through content analysis. The results of the analysis showed that strategies to cope with depression used by participants were composed of 6 domains and 11 sub-domains: health behavior (medical approach / exercise and diet), family and social contact (social interaction / going out and going on a trip / communication with family), Religious activities (Religious activities), lifelong education (hobbies / educational activities), productive activities (labor), health risk behaviors (drinking and gambling / resignation). The depression coping strategies of the older adults and their characteristics are as follows. First, older adults used diverse problem-focused coping strategies to cope with depression. Second, older adults considered various coping strategies together and used them simultaneously. Third, the facility space for older adults functions as a shelter. Fourth, although there were cases where medical approach was used, the intention to reuse was very low. Through this study, the following suggestions were made to help older adults cope with depression more successfully. First, access to various coping strategies should be promoted. Second, more places where older adults can spend their time comfortably need to be provided. Third, resistance to mental health care should be resolved.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.305-312
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• 2021

This study aims to analyze the changes (2011→2021) in social and environmental factors, such as actual construction activities, including building development and officially assessed individual land price, of the areas that have been released from the park during the second national park area adjustment period (2010~2011) and compare them with those of the areas that retained parks in the same period to analyze the development impact. In the released area, a building has been constructed per 16,431 square meters since 2011. Moreover, both the number of floors and height of the building has increased, and it was analyzed that the class 2 neighborhood living facilities occupied the highest proportion of the building use. Officially assessed individual land prices increased by 42.3% in the released area and 38.6% in the retained area. The analysis by region showed that the officially assessed land price increased by 55.2% on average in both released and retained areas in Seoul and 9.4% in Gyeonggi-do, indicating a much larger increase in the Seoul region. The issue of private property rights in national parks was mostly resolved as they were released through the second national park area adjustment. However, the Korea National Park needs to promote the benefits of landowners by suggesting rational alternatives such as adjustments to the park zoning and facility planning.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.35-53
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• 2021

Over the past 20 years, Korea's number of international passengers and freight transportation records has increased by 8.6% per year, respectively. However, despite the development of sea lanes and increased voyages, there have been constant calls for improving the inefficient management of international passenger ports. Hence, this paper presents improvements and further directions for international passenger port management. Focusing on the Incheon International passenger port as a representative case study, the main results show that the most important, urgent, possible measures for improving the port management include (i) the expansion of customs personnel and implementation of a 24-hours customs clearance system in operation, (ii) installation of buffer facilities between the ferry and ferry cargo and establishment of hinterland specialized in car ferry freight in a facility, and (iii) clear standards for cost-bearing subjects and limitation of high cost related to terminal use in institution. These results imply the need for government policy access and investment reflecting stakeholder opinions at various levels, such as operation, facilities, institution, and so forth, for efficient management of international passenger ports.