• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.3
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• pp.190-200
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• 2022

In this study, the island's land-use and land-cover change (LULCC) is analyzed in South Korea using remotely sensed land cover data(Globeland 30) acquired from 2000 to 2020 to meet the requirement of providing practical information for forest management. Analysis of LULCC between the 2000 and 2020 images revealed that changes to agricultural land were the most common type of change (7.6% of pixels), followed by changes to the forest (5.7%). The islands forests maintain 157,246 ha (42.2% of the total island area). Land cover types that changed to the forest from grasslands were 262 islands, while reverse cases have occurred on 421 islands. These 683 islands have a possibility of transition and disturbance. The artificial land class was newly calculated in 22 islands. The forests, which account for 42.2% of the 22 island area, turned into grassland, and 27.8% of agricultural land and grassland turned into forests. The development of artificial land often affects developed areas and surrounding areas, resulting in deforestation, management of agriculture, and landscaping. This study can provide insights concerning the fundamental data for assessing ecological functions and constructing forest management plans in islands ecosystems.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.144-150
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• 2021

The purpose of this paper is to introduce representative appropriate technology research organizations operating in France. Among them, we would like to investigate and introduce five institutions that have acquired a lot of experience due to their long history. Institut de Recherche pour le Développement (IRD) is a government-funded institution that strengthens science and technology infrastructure in Africa and overseas territories with the aim of supporting and educating science communities in developing countries, and conducts collaborative research with more diverse developing countries. Antenna France is an NGO organization whose main activity is to improve malnutrition in Africa. Ingénieurs sans frontiers is an NGO organization that sets sustainable development as the main goal of the association's activities and leads various activities such as education. Terre & Humanism is an NGO organization that practices ecological agriculture and carries out a social change movement urging to respect life and land, and to constitute an alternative society. Humanitarian Design Bureau is a corporation concept company that mainly carries out R&D for environmentally friendly products necessary for NGO activities.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.130-136
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• 2021

This study investigated the general characteristics of mobility disadvantaged persons with disabilities, and to suggest implications to ensure personal mobility with the greatest possible independence for the physically disabled in community. The survey questionnaire included the categories as follows: the general characteristics of the participants, the status of outing and mobility, usage of low-floor buses & taxi for the disabled, service improvement, and mobile support center. Data collected from 219 with physical disabilities were analyzed for this purpose by using descriptive statistics. The study results showed that 54.6% of the total tended to go out everyday, and 17.0% rarely. 53.4% could go out without any assistance, and the major obstacles not to go out were stairs and inconvenience of public transportation. 26.9% used low-floor buses, and 71.1% preferred to use taxi for the disabled. The average waiting time for the usage of low-flow buses and taxi was 66.57 minute and 42.65 minute, separately. 78.7% insisted that the function of mobile support center in the community should be expanded, whereas only 49.8% recognized the role of mobile support center. Based on the study results, the researchers suggested to facilitate access by persons with disabilities to mobility aids, and to improve the actual state of pedestrian environment. In addition, the function of mobile support center should be expanded to help the mobility disadvantaged persons live independently in community, thereby contributing to the promotion of their quality of life.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.589-601
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• 2021

Artificial recharge technology is a method for solving problems such as groundwater level drop and ground subsidence caused by groundwater withdrawal. This study investigated the applicability of using the hydraulic conductivity of an aquifer to predict injection test results for aquifer restoration. Pumping and injection tests were performed under the same conditions as those for the artificial injection facility located in Icheon, Gyeonggi-do. The hydraulic conductivity of the aquifer, which plays a decisive role in restoring the groundwater level, was derived from the pumping test. A numerical model of a simplified on-site aquifer was constructed, and a transient analysis was applied with the same conditions as the pumping test. The correlation between the measured and the resulting model values is strong (R² = 0.78). The injection test was performed in a sedimentary layer composed of silt sand and clay sand. From the results of the injection test, an empirical formula was derived using Theim's formula, which is a common well analysis solution to determine the parameters of the aquifer from time-level data. The model values from the empirical formula have a high degree of correlation (R² = 0.99) with measured values. Under specific conditions, for areas where it is difficult to conduct an injection test, the formula from this study, which relies on the hydraulic conductivity of the aquifer determined through the pumping test, may be used to predict reliable injection rates for groundwater restoration.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.94-101
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• 2021

According to the Facility Management System (FMS) operated by the Korea Authority of Land & Infrastructure Safety, it is expected that the number of aging facilities that have been in use for more than 30 years will increase rapidly to 13.9% in 2019 and 34.5% in 2929, and end up with a social problem. In addition, with the revision of "Common Application of Seismic Design Criteria" by the Ministry of Public Administration and Security in 2017, it is mandatory to re-evaluate all existing road facilities and if necessary seismic reinforcement should be done to minimize the magnitude of earthquake damage and perform normal road functions. The seismic performance management-decision support technology currently used in seismic performance management practice in Korea only determines the earthquake-resistance reinforcement priority based on the qualitative index value for the seismic performance of individual facilities. However with this practice, normal traffic functions cannot be guaranteed. A new seismic performance management decision support technology that can provide various judgment data required for decision making is needed to overcome these shortcomings and better perform seismic performance management from a road network perspective.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.570-575
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• 2022

The MX-S2X, utilizing high-frequency broadband communication technology, provides a reliable connection between land, ship, and facilities. This technology is expected to be effectively utilized as a future maritime communication infrastructure in the upcoming mixed navigational situation among autonomous and manned and/or unmanned ships. Following the physical layer design and M&S-based performance analysis of the MX-S2X system to overcome maritime multipath fading, this paper confirms the optimized and detailed design of physical layer hardware and implemented it to verify the performance. The PER(Packet Error Rate) performance was then measured by configuring a test environment to verify the implemented hardware. The results showed that the performance degradation was 0.2 dB in the AWGN environment and 1.2 dB in the Multi-path Fading on Sea Environment, thus confirming the successful implementation of the physical layer.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.1
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• pp.31-40
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• 2023

Various policies and services are being implemented in Korea and other countries, such as the expansion of convenience facilities for mobility support, the provision of special means of transportation, and the establishment of public transportation route plans and fare policies based on data and AI-based movement pattern analysis to ensure the mobility rights of the weak in transportation. However, A research is still needed to improve service convenience in order to more conveniently use the desired means of transportation in a necessary situation from the viewpoint of the transportation vulnerable. This study examines the policies and services for the promotion of mobility for the transportation disadvantaged, and presents a MyData-based service model for mobility support for the transportation disadvantaged. In the proposed service model, the transportation-disabled person can freely choose and use the means of transportation according to individual circumstances, and receive the same transportation welfare voucher benefits provided by the state or government. The proposed service model defines the MyData platform that supports the safe collection and use of personal data, the authentication of traffic welfare recipients based on MyData, and the payment function for fee settlement after using the service as key components. In this research, the service satisfaction from the user's point of view was investigated by implementing the proposed service model and providing a demonstration service for the transportation vulnerable in Daejeon.

• Journal of Industrial Convergence
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• v.20 no.9
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• pp.131-139
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• 2022

The purpose of this study was to ensure that the elderly do not enter a facility even if their health deteriorates, but continue to live in the community and receive necessary care. According to the survey of the elderly, the cohabitation type of the elderly in Korea was that they lived with married adults and/or unmarried children in addition to single and married households. Therefore, in this study, using the SPSS 25 program, the effects of the elderly's socio-demographic characteristics and cohabitation type on the intention to continue living in the community was analyzed using the 2020 elderly welfare status survey data. The main research results are as follows. First, gender, age, and residence type of the demographic characteristics of the elderly were found to be statistically significant. Second, single households, married households, and households living with the eldest son revealed the statistical significance level of the elderly. Based on this, we were intending to provide basic data necessary for establishing welfare policies for the elderly, such as strengthening care and an age-friendly environment, in order to improve the continued residence of the elderly in the local community.

• Journal of Internet Computing and Services
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• v.23 no.6
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• pp.27-37
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• 2022

Virtual private network (VPN) services are used in various environments related to national security, such as defense companies and defense-related institutions where digital communication environment technologies are diversified and access to network use is increasing. However, the number of cyber attacks that target vulnerable points of the VPN has annually increased through technological advancement. Thus, this study identified security requirements by performing STRIDE threat modeling to prevent potential and new vulnerable points that can occur in the VPN. STRIDE threat modeling classifies threats into six categories to systematically identify threats. To apply the proposed security requirements, this study analyzed functions of the VPN and formed a data flow diagram in the VPN service process. Then, it collected threats that can take place in the VPN and analyzed the STRIDE threat model based on data of the collected threats. The data flow diagram in the VPN service process, which was established by this study, included 96 STRIDE threats. This study formed a threat scenario to analyze attack routes of the classified threats and derived 30 security requirements for each element of the VPN based on the formed scenario. This study has significance in that it presented a security guideline for enhancing security stability of the VPN used in facilities that require high-level security, such as the Ministry of National Defense (MND).

• Journal of the Korean GEO-environmental Society
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• v.22 no.12
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• pp.33-40
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• 2021

The deterioration of underground facilities, disturbance of the ground due to underground development activities, and changes in ground water can cause ground subsidence accidents in the urban areas. The investigation on the geotechnical and hydraulic factors affecting the ground subsidence accident is very significant to predict the ground subsidence risk in advance. In this study, an analysis DB was constructed through 3D ground modeling to utilize the currently operating geotechnical survey information DB and ground water behavior information for risk prediction. Additionally, using these results, the relationship between the actual ground subsidence occurrence history and ground conditions and ground water level changes was confirmed. Furthermore, the methodology used to visualize the risk of ground subsidence was presented by reconstructing the engineering characteristics of the soil presented according to the Unified Soil Classification System (USCS) in the existing geotechnical survey information into the internal erosion sensitivity of the soil, Based on the result, it was confirmed that the ground in the area where the ground subsidence occurred consists of more than 40% of sand (SM, SC, SP, SW) vulnerable to internal erosion. In addition, the effect of the occurrence frequency of ground subsidence due to the change in ground water level is also confirmed.