• Journal of the Korean GEO-environmental Society
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• v.13 no.4
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• pp.77-91
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• 2012

Recently, construction of housing sites, complexes, roads, ports and airports is increasing for high-intensity use of the country and balanced development between regions. Presently, constructions are being conducted at soft ground. Consequently, engineering problems as long-term settlement of the ground, differential settlement, local structural damage have been reported consistently at construction site. In particular, long-term subsidence of the ground as various constructions and loads by the load will necessarily occur in the soft ground of west-south coast and inland coast. Therefore, in this study, regional proper analysis methods of the Hyperbole method, Hosino method, $\sqrt{S}$ method, Asaoka method etc as existing long-term settlement prediction methods have been examined and a study on new prediction method was conducted through deduction of a generalized equation. Correlation coefficients of soil properties and construction conditions has been analyzed and a matching coefficient of long-term settlement characteristics has been deducted. Comparison and analysis of monitoring data and numerical analysis results of 16 local area have been conducted.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.36 no.5
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• pp.41-51
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• 2020

As there are the elderly who have difficulty in evacuating themselves, it is necessary to develop architectural and institutional planning for nursing homes that can minimize disaster damage. The purpose of this study was to suggest the improvement plan by grasping the current status of nursing homes on planning aspects such as floor plan type, spatial layout, and evacuation route through 14 case studies in Cheongju city in terms of disaster safety. The results of this study were as follows; the most common plan type was the grouped-corridor type difficulty in securing evacuation routes. The circulation corridor type is need to be considered because it is possible not only to secure evacuation and nursing routes, but also to create a hanging around corridor for the elderly with dementia. Second, if there is a risk of flooding due to the location, the living room should be placed on the 2nd floor or more. In particular, a kitchen should be placed not adjacent to the entrance and the vertical evacuation route. Third, the horizontal evacuation route should be arranged differently depending on the floor plan type. For vertical evacuation routes, it is necessary to install outdoor stairs or ramps considering the evacuation characteristics of the elderly. In addition, the institutional aspects should be considered to ensure the safety of disasters.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.6
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• pp.1-14
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• 2020

Under the 「National Land Planning and Utilization Act」, Development Restriction Zones(DRZ) is one of the designated use district where the Minister of Land, Infrastructure and Transport deems it necessary to control urban development in order to prevent urban sprawl and conurbation and ensure a healthy living environment for citizens by conserving the natural environment surrounding metropolitan cities. DRZ was first designated around the Seoul Metropolitan city in 1971, and had been expanded to the 14 metropolitan areas across the country since 1977. The designated areas were accounted for about 5.4% of the total national land and its importance was demonstrated by contributing to control urban sprawl, curbing real estate speculation, and providing green space to citizens. However, DRZ has been repeatedly relaxed its regulations and allowed development under government. As a result, much of the green areas was damaged and several cities were merged and extended(conurbation). In particular, deregulation implemented for the purpose of securing land as part of national projects and local outstanding business(i.g. constructions of national rental housing, industrial complex, and international stadium) have caused continuous environmental damage around the metropolitan cities. In addition, the habitat fragmentation is in serious situation. Thus, the systematic plans for managing DRZ are necessary, since it is concerned that urban environment become deteriorate in the mid- to long-term. This study aims to continuously protect the urban environment from lifting DRZ. Therefore, firstly, we examined the environmental status through analyzing DRZ Management Plan which shall be drawn up by the Special Metropolitan City Mayor, the Metropolitan City Mayor or the Mayer/Do governor having jurisdiction, every five years to collectively manage DRZ. Secondly, we investigated the actual condition in DRZ based on the case study of Management Plan in Metropolitan areas(i.e. Seoul Metropolis, Gyeonggi-do, and Incheon Metropolis). Finally, we suggested the seven feasible improved political plan for managing DRZ.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.282-300
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• 2021

The purpose of this study was to explore what social media posts tell us about family life during the COVID-19 pandemic by examining the keywords and topics underlying posts on blogs and online forums. Our criteria for web crawling were (a) blog and forum posts on Naver and Daum, the top portal sites in Korea, (b) posts between February 23 and April 19, 2020, the period of the first heightened social distancing orders, and (c) inclusion of "COVID" and "family" or "COVID" and "home." We analyzed 351,734 posts using TF-IDF values and topic modeling based on latent Dirichlet allocation. We identified and named 22 topics including COVID-19 prevention, family infection, family health, dietary life and changes, religious life, stuck at home, postponed school year, family events, travel and vacations, concerns about family and friends, anxiety and stress, disaster and damage, COVID-19 warning text messages, family support policies, Shin-cheon-ji and Daegu. The results show that COVID-19 impacted various domains of family life including health, food, housing, religion, child care, education, rituals, and leisure as well as relationships and emotions.

• Journal of the Korean Wood Science and Technology
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• v.49 no.2
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• pp.181-190
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• 2021

Screw-type fasteners are widely used to make connections between wood members or between wood and steel connectors because they can tolerate the applied loads by withdrawal or shearing. In this study, we evaluated the withdrawal resistances of the screw-type fasteners and analyzed the effects of the lead-hole size, relative grain direction (tangential, radial, and cross-sections) of the wood member, screw diameter, screw type, and species. Two wood species, including domestic larch and imported spruce, and three screw-type fasteners, including domestic lag screws (diameters of 9.46, 7.79, and 6.27 mm), domestic tapping screw (diameter, 6.3 mm), and imported Sherpa screw (diameter, 8.0 mm) were used. To assess the effect of lead-hole size, the lead holes with diameters corresponding to 68.7%, 70.8%, and 74.0% of the shank diameter of the lag screw were predrilled. The lead hole corresponding to 74% of the shank diameter was selected for this study because the smaller lead holes required higher rotational force for installation, which may cause damage in the screw neck, although there was no significant difference in the withdrawal resistance depending on the lead-hole sizes applied in this study. The lag screws installed on the tangential and radial surfaces showed similar withdrawal resistances to each other, which were greater than those installed on the cross-sectional surface. As the lag screw diameter increased from 6.27 mm to 9.46 mm, the withdrawal resistance also increased proportionally. The withdrawal resistance of the tapping screw having a diameter of 6.3 mm was almost 1.6 times higher than that of the lag screw having a similar diameter of 6.27 mm, while that of Sherpa screw having a diameter of 8.0 mm was around 1.4 times higher than that of the lag screw having a similar diameter of 7.79 mm.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.596-605
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• 2022

This study aimed to introduce research on coerced debt victimization and interventions in the context of domestic violence. To achieve the aim, this study reviewed existing studies on coerced debt conducted in the US. This study discussed the followings: First, coerced debt was theorized by coerced control theory of domestic violence and control mechanisms of economic abuse and conceptualized as fraud and force. Second, the effects of coerced debt included credit damage, economic dependence, and barriers to housing, employment, and safety. Third, to intervene the victimization, service providers should endure uncertainty and its time consuming process of recovering, provide an intense and personalized advocacy, and overcome the problems of absence of policies to support the victims. Finally, service providers should have educations and training programs on the assessment and intervention skills of coerced debt acknowledging empowerment and safety of the victims as the most important.

• Journal of the Korean Regional Science Association
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• v.39 no.2
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• pp.63-76
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• 2023

Recently, due to the location of residential complexes in commercial areas of large cities, the urban function is shifting from commercial to residential.In order to improve the use volume system in the commercial area of Daejeon Metropolitan City, the system of special and metropolitan cities was compared and analyzed, and problems were derived by analyzing 8 cases. First, use classification of mixed-residential buildings, Second, unbalance of urban planning for functional loss of commercial area, Thrid, damage on urban environment due to difference of development density. Accordingly, improvement measures include First, securing the ratio of residential function and mixed use at least 10%, Second, securing urban competitiveness by inducing facilities that combine various uses and functions. The overall floor area ratio of housing is applied, Third, the development density is presented through the establishment of the district unit plan and consultation.

• Structural Engineering and Mechanics
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• v.90 no.1
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• pp.19-26
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• 2024

In recent years, an increasing number of experimental studies have shown that the practical application of mature active control systems requires consideration of robustness criteria in the design process, including the reduction of tracking errors, operational resistance to external disturbances, and measurement noise, as well as robustness and stability. Good uncertainty prediction is thus proposed to solve problems caused by poor parameter selection and to remove the effects of dynamic coupling between degrees of freedom (DOF) in nonlinear systems. To overcome the stability problem, this study develops an advanced adaptive predictive fuzzy controller, which not only solves the programming problem of determining system stability but also uses the law of linear matrix inequality (LMI) to modify the fuzzy problem. The following parameters are used to manipulate the fuzzy controller of the robotic system to improve its control performance. The simulations for system uncertainty in the controller design emphasized the use of acceleration feedback for practical reasons. The simulation results also show that the proposed H∞ controller has excellent performance and reliability, and the effectiveness of the LMI-based method is also recognized. Therefore, this dynamic control method is suitable for seismic protection of civil buildings. The objectives of this document are access to adequate, safe, and affordable housing and basic services, promotion of inclusive and sustainable urbanization, implementation of sustainable disaster-resilient construction, sustainable planning, and sustainable management of human settlements. Simulation results of linear and non-linear structures demonstrate the ability of this method to identify structures and their changes due to damage. Therefore, with the continuous development of artificial intelligence and fuzzy theory, it seems that this goal will be achieved in the near future.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.63-70
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• 2024

Lithium-ion batteries (LIB) are widely used in various sectors, such as transportation (e.g., electric vehicles (EV)) and energy (e.g., energy storage facilities) due to their high energy density, broad operating temperature (-20 ℃ ~ 60 ℃), and high capacities. LIBs are powerful but fragile on external factors, including pressure, physical damage, overheating, and overcharging, that cause thermal runaway causing fires and explosions. During a LIB fire, a large amount of oxygen is generated from the decomposition of ionogenic materials. A water fire extinguisher that helps with cooling and suffocating must be essentially required at the same time. In fact, however, it is difficult to suppress LIB fires in the case of EVs because a LIB is installed with a battery pack housing that interrupts direct extinguishing by water. Thus, this study aims to investigate effective fire extinguishing measurements for LIB fires by using an EV. Relevant documents, including research articles and reports, were reviewed to identify effective ways of LIBs fire extinguishing. A real-scale fire experiment generating thermal runaway was carried out to figure out the combustion characteristics of EVs. This study revealed that the most effective fire extinguishing measurements for LIB fires are applying fire blankets and water tanks. However, there is still a lack of adequate regulation and guidelines for LIB fire extinguishment. Taking this into account, developing functional fire extinguishment measurements and available regulatory instruments is an urgent issue to secure the safety of firefighters and citizens.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.3
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• pp.58-69
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• 2018

This study investigated root damage characteristics and correlations between roadside trees and street furniture through the investigation of the root damage conditions and the current status of roadside trees and street furniture in Seo-gu, Daejeon City where the occurrence of pavement uplift is frequent. The study area was divided into six areas by species of trees as Metasequoia glyptostroboides and Platanus occidentalis focusing on the streets that were installed with trees chest height and 8cm round planted at the time of the development of the Dunsan-dong Housing Site Development in Seo-gu, Daejeon metropolitan city (1990~1994). The damage rate of roadside protection frames (95.3%) was higher than that of curbstones (19.7%) at the study site. Streets without a protective frame were more likely to have damaged pavement. In addition, the frequency of breakage of protective frames was lowered when a drinking water area was increased to more than a certain level. The frequency of the type of uplift in the sidewalk pavement surfaces is in the order of tail type > mounding type > irregular type, and the frequency of the uplift direction is the highest in Direction 1 ($0{\sim}44^{\circ}C$), Direction 2 ($45{\sim}89^{\circ}$), and Direction 3 ($95{\sim}134^{\circ}$) when $180^{\circ}$ of the street direction is based on $90^{\circ}$ parallel to the curbstone. The uplift length is about 31~60cm and it is most often at a height of 3~6cm. When comparing the results of uplift deformation, Metasequoia glyptostroboides was found to be higher than the deformation of Platanus occidentalis. In addition, it can be seen that the larger the length, width and height of the ridge, the larger the deformation becomes. The relationship between the diameter at breast height, the dimension of the pavement width, the frequency of the ridge phenomenon and the deformation amount is not necessarily proportional, and there seems to be a gap due to external factors such as soil humidity and planting base. Therefore there is a need for a multi-directional approach in reducing uplift.