• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2377-2398
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• 2023

In our daily lives, we engage in a variety of tasks that rely on our senses, such as seeing. Blindness is the absence of the sense of vision. According to the World Health Organization, 2.2 billion people worldwide suffer from various forms of vision impairment. Unfortunately, blind people face a variety of indoor and outdoor challenges on a daily basis, limiting their mobility and preventing them from engaging in other activities. Blind people are very vulnerable to a variety of hazards, including falls. Various barriers, such as stairs, can cause a fall. The Internet of Things (IoT) is used to track falls and send a warning message to the blind caretakers. One of the gaps in the previous works is that they were unable to differentiate between falls true and false. Treating false falls as true falls results in many false alarms being sent to the blind caretakers and thus, they may reject the IoT system. As a means of bridging this chasm, this paper proposes an intelligent shoe that is able to precisely distinguish between false and true falls based on three sensors, namely, the load scale sensor, the light sensor, and the Flex sensor. The proposed IoT system is tested in an indoor environment for various scenarios of falls using four models of machine learning. The results from our system showed an accuracy of 0.96%. Compared to the state-of-the-art, our system is simpler and more accurate since it avoids sending false alarms to the blind caretakers.

• Progress in Superconductivity and Cryogenics
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• v.25 no.4
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• pp.65-69
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• 2023

Hydrogen is an eco-friendly energy source and is being actively researched in various fields around the world, including mobility and aerospace. In order to effectively utilize hydrogen energy, it should be used in a liquid state with high energy storage density, but when hydrogen is stored in a liquid state, BOG (boil-off gas) is generated due to the temperature difference with the atmosphere. This should be re-condensed when considering storage efficiency and economy. In particular, large-capacity liquid hydrogen storage tank is required a gaseous helium circulation cooling system that cools by circulating cryogenic refrigerant due to the increase in heat intrusion from external air as the heat transfer area increases and the wide distribution of the gas layer inside the tank. In order to effectively apply the system, thermo-hydraulic analysis through process analysis is required. In this study, the condenser design and system characteristics of a gaseous helium circulation cooling system for BOG recondensation of a liquefied hydrogen storage tank were compared.

• Korea Trade Review
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• v.46 no.1
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• pp.59-81
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• 2021

This paper aims to analyze Korea's trade and investment performance in Spain and the business environment of Spain, and to find efficient strategies for entering into the Spanish market. This study is organized into five chapters. To begin with, it explains an overview of the Spanish economy and the current status of its major industries. Then, it analyzes Korea's trade and investment performance in Spain, the structure of comparative advantage and the trade trends of major import and export items, since 2011 when the Korea-EU FTA went into effect. Lastly, based on the results of this analysis, Korea's strategies for entering into the Spanish market are derived. The strategies derived from the analysis are as follows: (1) entering startups in the Spanish market through CVC cooperation and participation in large tech forums, (2) linking the Spanish interest in K-Culture to consumer goods exports, (3) promoting cooperation in the IT industry in response to the Spanish government's 'Connected Industry 4.0', (4) building a new Korean-Spanish value chain in response to the mobility revolution, (5) advancing jointly into a third country by combining the strengths of both Korea and Spain, (6) cooperating with the Spanish government to establish a sustainable energy policy, (7) promoting jointly with the Spanish government through smart city strategies and project exchanges, and (8) building a European logistics hub in Spain in preparation for post-Brexit.

• Smart Structures and Systems
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• v.32 no.4
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• pp.207-218
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• 2023

Real-time monitoring of the behavior of reinforced soil retaining wall (RSW) is required for safety checks. In this study, a targetless displacement measurement technology (TDMT) consisting of an image registration module and a displacement calculation module was proposed to monitor the behavior of RSW, in which facing displacement and settlement typically occur. Laboratory and field experiments were conducted to compare the measuring performance of natural target (NT) with the performance of artificial target (AT). Feature count- and location-based performance metrics and displacement calculation performance were analyzed to determine their correlations. The results of laboratory and field experiments showed that the feature location-based performance metric was more relevant to the displacement calculation performance than the feature count-based performance metric. The mean relative errors of the TDMT were less than 1.69 % and 5.50 % for the laboratory and field experiments, respectively. The proposed TDMT can accurately monitor the behavior of RSW for real-time safety checks.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.693-699
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• 2024

The main cause of scattering dust generated by transportation equipment such as automobiles was largely due to exhaust gas from internal combustion engines in the past, but it was generally recognized that non-exhaust causes such as abrasion of the tires or brake pads were low. Accordingly, scattering dust generated by exhaust gas has consistently existed in many studies, such as technological progress and related regulations, but research on non-exhaust is relatively insignificant, and the need for research on scattering dust generated by non-exhaust is emerging. In this study, a dust collector that can be easily mounted on a caliper to collect scattering dust generated by pad wear during the brake operation of an automobile was manufactured. In this study, we developed a dust collector that is easy to mount on calipers to collect scattering dust caused by pad wear during brake operation of automobiles. According to the installation of the manufactured dust collector, the performance of scattering dust by brake operation and the temperature change characteristics of calipers according to the structure of the dust collector were evaluated.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.2
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• pp.77-87
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• 2024

In the present study, seakeeping performance for an amphibious vehicle in regular head waves was analyzed and evaluated experimentally and numerically. First, seakeeping tests were performed to confirm the vehicle's motion response of heave, pitch motion and vertical acceleration in restricted wavelength ratio conditions for a simplified vehicle shape. Numerical analyses were also conducted for a simplified vehicle shape to validate the numerical solver. To simulate the vehicle's motions, multi-degrees of freedom were calculated by a dynamic fluid-body interaction solver in STAR-CCM+. Comparison between numerical and experimental results was carried out for a simplified vehicle shape. Numerical results are in good agreement with experimental results. Second, numerical analyses were performed for a detailed vehicle shape considering seaway wavelength conditions. The seakeeping performance for an amphibious vehicle was evaluated by comparing with the existing ship's seakeeping performance standards.

• International journal of advanced smart convergence
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• v.13 no.3
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• pp.345-357
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• 2024

High rise hotels are densely populated and have complex ignition sources. Once a fire occurs, it can cause serious casualties and property damage. The impact of a fire is greater on special groups such as the elderly and children who move slowly. At present, research mainly focuses on the impact of high-rise building structures on evacuation consequences, but there is little research on the safety evacuation consequences of elderly and children in high-rise hotels, as well as the behavior of people in groups during the safety evacuation process. Therefore, we propose to use Pathfinder software to simulate three scenarios for the elderly and children in high-rise hotels. Scenario 1 involves arranging the elderly and children on higher floors, Scenario 2 involves arranging them on middle floors, and Scenario 2 involves arranging them on lower floors. We further provide three types of personnel pairing schemes for each scenario, namely: no one pairing, two people pairing, and three people pairing. Through simulation analysis, we found that placing elderly and children with lower mobility on lower floors resulted in the shortest safe evacuation time; The evacuation time for solo actions without companionship is the shortest, followed by two people in groups, and the safety evacuation time for three people in groups is the longest. Our research findings have significant implications for improving the evacuation efficiency of personnel in fire scenarios.

• Spatial Information Research
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• v.21 no.5
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• pp.83-91
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• 2013

As ICTs are more advanced, in the current Smart Society that can be characterized by the terms of real-time, mobility and customization, the area of Geospatial Information is required to react to the needs of the society in more practical ways. Because Geospatial Information is getting more accepted as one of the very basic social infrastructure for everyday life activities in all sectors of life. In accordance, the legal basis of convergence Geospatial Information services are described on Geospatial Information Industry Support Law(Article 2, Item 7 & Article 4 Item 5). But it is required to come up with more detailed and practical definition of convergence GIS with more detailed supporting policies. In this context, this study aims at investigating what the needs of Geospatial Information services are in the Smart Society, and suggesting the policy directions and realization strategies of convergence GIS based on spatial hierarchy from global to local.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.157-172
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• 2024

Autonomous driving technology, when commercialized, has the potential to improve the safety, mobility, and environmental performance of transportation networks. However, safe autonomous driving may be hindered by poor sensor performance and limitations in long-distance detection. Therefore, cooperative autonomous driving that can supplement information collected from surrounding vehicles and infrastructure is essential. In addition, since HDVs, AVs, and CAVs have different ranges of perceivable information and different response protocols, countermeasures are needed for mixed traffic that occur during the transition period of autonomous driving technology. There is a lack of research on traffic flow optimization that considers the penetration rate of autonomous vehicles and the different characteristics of each road segment. The objective of this study is to develop weights based on safety, operational, and environmental factors for each infrastructure control use case and autonomous vehicle MPR. To develop an integrated evaluation index, infra-guidance AHP and hybrid AHP weights were combined. Based on the results of this study, it can be used to give right of way to each vehicle to optimize mixed traffic.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.202-217
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• 2022

Purpose: The recent increased use of Personal Mobility (PM) has been accompanied by a rise in the annual number of accidents. Accordingly, the safety requirements for PM use are being strengthened, but the laws/systems, infrastructure, and management systems remain insufficient for fostering a safe environment. Therefore, this study comprehensively searches the main problems and improvement methods through a review of previous studies that are related to PM. Then the priorities according to the importance of the improvement methods are presented through the Delphi survey. Method: The research method is mainly composed of a literature study and an expert survey (Delphi survey). Prior research and improvement cases (local governments, government departments, companies, etc.) are reviewed to derive problems and improvements, and a problem/improvement classification table is created based on keywords. Based on the classification contents, an expert survey is conducted to derive a priority improvement plan. Result: The PM-related problems were in 'non-compliance with traffic laws, lack of knowledge, inexperienced operation, and lack of safety awareness' in relation to human factors, and 'device characteristics, road-drivable space, road facilities, parking facilities' in relation to physical factors. 'Management/supervision, product management, user management, education/training' as administrative factors and legal factors are divided into 'absence/sufficiency of law, confusion/duplication, reduced effectiveness'. Improvement tasks related to this include 'PM education/public relations, parking/return, road improvement, PM registration/management, insurance, safety standards, traffic standards, PM device safety, PM supplementary facilities, enforcement/management, dedicated organization, service providers, management system, and related laws/institutional improvement', and 42 detailed tasks are derived for these 14 core tasks. The results for the importance evaluation of detailed tasks show that the tasks with a high overall average for the evaluation items of cost, time, effect, urgency, and feasibility were 'strengthening crackdown/instruction activities, education publicity/campaign, truancy PM management, and clarification of traffic rules'. Conclusion: The PM market is experiencing gradual growth based on shared services and a safe environment for PM use must be ensured along with industrial revitalization. In this respect, this study seeks out the major problems and improvement plans related to PM from a comprehensive point of view and prioritizes the necessary improvement measures. Therefore, it can serve as a basis of data for future policy establishment. In the future, in-depth data supplementation will be required for each key improvement area for practical policy application.