• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.6
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• pp.751-762
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• 2022

Welded head studs are mainly used as shear connectors to bond steel girders and concrete slabs in steel-concrete composite bridges. For welded shear connectors, environmental problems include noise and scattering dust which are generated during the removal of damaged or aged slabs. Therefore, it is necessary to develop demountable shear connectors that can easily replace aged concrete slabs for efficient maintenance and thus for better management of environmental problems and life cycle costs. The buried nut method is commonly studied in relation to bolted shear connectors, but this method is not used in civil structures such as bridges due to low rigidity, low shear resistance, and increased initial slip. In this study, in order to mitigate these problems, a demountable bolted shear connector is proposed in which the buried nut is integrated into the stud column and has a tapered shape at the bottom of an enlarged column shank. To verify the performance of the proposed demountable stud bolts in terms of static shear strength and slip displacement, a horizontal shear test was conducted, with the performance outcomes compared to those of conventional welded studs. It was confirmed that the proposed demountable bolted shear connector is capable of excellent shear performance and that it satisfies the slip displacement and ductility design criteria, meaning that it is feasible as a replacement for existing welding studs.

• The Journal of the Korea Contents Association
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• v.22 no.2
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• pp.58-70
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• 2022

The emergency preparedness exercise currently conducted by the government has been conducted as a message-based exercise for more than 50 years. Therefore, in this study, a simulation-based maintenance practice model was developed focusing on infectious disease situations, and the possibility of a training system applying scientific techniques was presented. As a result, First, a simulatioon logic assuming an infectious disease outbreak situation was developed. The situation of an infectious disease outbreak was made to occur when measures are not taken within 24 hours for the death due to disease, and when appropriate measures are not taken for contaminated food (24 hours), drinking water (12 hours), and drinking water shortage (24 hours). Second, in order to implement the simulation logic, simulation engine SW was developed for emergency medical team, epidemiological investigation team, dead burial team, quarantine and disinfection team, etc., and situation map SW was developed so that these contents could be expressed in the situation map. As suggested in this paper, if scientific techniques are applied to the simulation-based government practice model to expand the scope, training will be possible by creating practical situations that can occur in the real world, and the Chungmu plan and various emergency preparedness plans will be verified.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.653-659
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• 2022

In this study, the awareness of hazardous chemicals and the need for education of dental hygienists were investigated. The subject of this study was an online survey of 103 dental hygienists working in medical institutions from June to August 2021 and analyzed using the SPSS 21.0 program. As a result, work experience was positively correlated with perception (r=.280, p<0.01) and work (r=.303, p<0.01), and work experience with perception (r=.411, p<0.01).Hazardous chemical information showed a positive correlation with practice (r=.371, p<0.01). As a result of the education requirement survey, only 27.2% had experience in hazardous chemical education, and 96.1% of the awareness of the need for education was highly surveyed. As for the desired method of education, 49.5% of them were online education, and the desired time for education was 1 hour. Therefore, in order to create a safe working environment for dental hygienists and to secure the safety of hazardous chemicals, it was necessary to expand educational opportunities at universities, medical institutions, and maintenance education, and to increase accessibility through online education.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.79-88
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• 2022

Cable-supported bridges, as important large infrastructures, require a long-term and systematic maintenance strategy. In particular, various methods have been proposed to secure safety for the bridges, such as installing various types of sensor on members in the bridges, and setting management thresholds. It is evidently necessary to propose a strategic plan to efficiently manage increasing number of cable-supported bridges and data collected from a number of sensors. This study aims to develop an analysis tool that can automatically remove abnormal signals and calculate statistical results for the purpose of efficiently analyzing a wide range of data collected from a long span bridge measurement system. To develop the tool, basic information such as the types and quantity of sensors installed in long span bridges and signal characteristics of the collected data were analyzed. Thereafter, the Humpel filtering method was used to determine the presence or absence of an abnormality in the signal and then filtered. The statistical results with filtered data were shown. Finally, one cable-stayed bridge and one suspension bridge currently in use were chosen as the target bridges to verify the performance of the developed tool. Signal processing and statistical analysis with the tool were performed. The results are similar to the results reported in the existing work.

• Korean Journal of Culture and Social Issue
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• v.27 no.4
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• pp.529-559
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• 2021

This study examines how people perceive and experience busyness, which is a great social pressure in the Korean society, and The socio-psychological motives that drive people's different paces of life, such as busyness or slowness, despite being in the same busy reality, were examined. Furthermore, an in-depth study was conducted on the adaptation factors in the real society according to the speed of individual life. The analysis of this study was based on an in-depth interview data of 21 unmarried men and women in their 20s and 30s, and was conducted using a phenomenological qualitative analysis method. As a result, the perception and experience of being busy had both positive and negative parts. The components of socio-psychological motivation that affect the speed of an individual's life are 'internalization of positive values of (busy/rest)', '(future/present) centric', 'selection & concentration/Inertial busyness', 'personality characteristics' were derived. In addition, 'self-selection', 'successful time management', and 'maintenance of psychological health' were derived as common factors among adaptation factors in real society, 'a sense of achievement' and 'understanding and accepting self-characteristics' were derived as discriminatory factors. became Based on these results, the value and meaning of being busy in Korean society was discussed from a social psychology perspective, and a new perspective was presented to existing studies and discussions related to the speed of life. In addition, several follow-up studies were proposed.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.5
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• pp.1-12
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• 2022

COVID-19 led to an increased need for mountainous urban parks in the city that can be enjoyed while moving rather than staying put. However, studies on the economic value of mountainous urban parks have been insufficient. As a result, this study investigates the economic value of Gyeyangsan, a mountainous urban park located in the city, by quantifying the value of natural resources provided to residents and analyzing the factors affecting these values. The results are summarized below. First, according to the economic value assessment of Gyeyangsan, the use value was 2,210 won per person or 4.42 billion won per year, and the preservation value was 6,182 won per household, or 129.37 billion won. Gyeyangsan's total assets value was assessed as 3.68 trillion won. Second, according to the estimates of the willingness to pay and the determinants for the use-value, the frequency of visits, age, and use satisfaction significantly impacted the intention to pay for the use-value. Third, according to the estimates of the willingness to pay and the determinants for the preservation value, the intention to revisit, volunteer participation, educational level, gender, and residence significantly influenced the intention to pay for the preservation value. According to the findings of this study, it will be possible to make crucial policy implications when setting a direction for future park management by presenting a practical policy plan for the maintenance of mountain parks in downtown areas and will broaden the scope of research.

• The Korean Society of Law and Medicine
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• v.23 no.4
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• pp.3-28
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• 2022

Recently, the targets and clauses of negotiation between 'National Health Insurance Service (NHIS)' and Pharmaceutical companies has been expanded. Due to newly adopted 'Quality management clause', 'Compulsory supply maintenance clause' and 'Penalty for breach of contract clause', not only 'Ministry of Health and Wellfare (MOHW)'s 'drug listing' and 'Price cap' announcement, but also 'negotiation between NHIS and pharmaceutical companies' can be a legal sanction to the suppliers. Once secretary of MOHW order NHIS to negotiate with pharmaceutical company, NHIS notify this order to the company and enter into the negotiation. 'The order' exists in the public domain between the government (MOHW) and public institutions (NHIS) and does not constrain the legal rights of companies (Therefore companies cannot pile a lawsuit about the order). However, 'the notice' or 'negotiation' is an act which has a counterpart, can be a target of administrative litigation if the company get some disadvantages from the talks. Negotiations can be divided into four types according to "the target (whether it is listed on the insurance benefit list)" and "the purpose (whether the target is price or conditional)." In particular, negotiations on listed drugs, whose goal is to set unfavorable conditions for companies, can be illegal if there is no price. So we need to consider compensation for the company as an incentive to negotiate.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.5
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• pp.543-553
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• 2023

This study was conducted to propose a simple method to evaluate the load-carrying capacity of RC slab bridges, which have been most frequently constructed in Korea. A number of RC slab bridges have been considerably deteriorated associate with the long service year. However, since these bridges are not included in the 1st and 2nd class infrastructures due to their short span length, they have been relatively neglected compared to other bridge types in terms of safety management. In the previous theoretical study, a process (draft) was proposed for evaluating the damage of RC slab bridges using the relationship between the displacement response ratio and the stiffness reduction rate derived by the measured displacement and natural frequency. In this paper, to verify the validity of the proposed damage evaluation process (draft), the results to the actual bridges were compared with the safety grade and the Matsui's deterioration index. In addition, to enhance the practical applicability of the existing process (draft), an improved method approximately evaluating the load-carrying capacity using only the measured natural frequency was presented. If an error of 10% of the load-carrying capacity is allowed, it is judged that the proposed damage evaluation process can be appropriately used not only for evaluating the safety of RC slab bridges, but also for determining priorities for their maintenance.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.27-35
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• 2009

KICT (Korea Institute of Construction and Technology) and KISTEC (Korea Infrastructure Safety and Technology Corporation) have been carrying out inventory survey on cut slopes along national roads since 2006. Unlike precision safety check, cut slope inventory survey is a simple check about cut slope's characteristics with the naked eye to collect the data base of slope maintenance. Inventory survey is classified into general status, cut slope characteristics and inspector opinions. The inventory data are analyzed to identify dangerous slopes and decide a safety ranking. In this paper, we performed a correlation analysis using SPSS (ver.15) about the 10,461 cut slope inventory data which are collected in Kangwondo and Chungcheongdo from 2006 to 2008. We calculated the correlation coefficient between cut slope inventory data and the danger score derived from the data. And we evaluated cut slope inventory data which have the more influence on the danger degree of cut slope. According to results of correlation analysis, we found that inventory data influencing cut slope danger degree are stuck and fallen rock, orientation of discontinuity and angle of upper slope. And these data are slightly different by regionally. Later on, if inventory research is finished, we will understand regional characteristics of cut slopes.

• Journal of Appropriate Technology
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• v.5 no.2
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• pp.106-113
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• 2019

In order to respond to the global environmental issues, developed countries have been helped the developing countries as the Official Development Assistance (ODA). It is important to understand technology needs of the developing countries to provide the optimum solutions. In this study, the information of the environmental R&D dealing with appropriate technology were comprehensively collected based on the conducted R&D projects from the ministry of environment in Korea. The technology needs by UNFCCC (United Nations Framework Convention on Climate Change) and Korean government were analyzed named as TNA and CPS according to the target developing countries. In South-East Asia and Africa region, there were technology needs on water, biota, air, solid wastes, infrastructures and resources. And they were related to the issues such as environmental pollution, construction, climate change, biodiversity, energy and water management. The technology needs by UNFCCC and Korean government were also compared. Furthermore, the environmental R&D on appropriate technology should be focused on localization and maintenance to provide sustainable solutions to the developing countries.