• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.495-505
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• 2019

This study reported the treatment of a patient with excessive worn dentition and limited maxillo-mandibular space for restoration, utilizing the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. After the thorough examination of the patient's occlusal vertical dimension (OVD), full mouth rehabilitation was planned with increase of the OVD. The patient was satisfied with the provisional restorations establishing the increased OVD. The horizontal and vertical data of the patient's jaw relation that the provisional restorations contained were transferred to the definitive metal ceramic fixed prostheses by double scanning and three-dimensional printing. After the fixed restorations were cemented to the abutments, electronic surveying and three-dimensional printing were used to fabricate metal frameworks for the patient's removable partial dentures. The mandibular definitive removable prostheses were delivered to the patient's mouth and the full mouth rehabilitation procedures were completed. The digital technologies used for this case produced fixed and removable restorations satisfactory in masticatory, phonetic and aesthetic functions to both the patient and the dental clinician.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.819-828
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• 2021

In urban regeneration projects, the core projects define the characteristics of the project site and contribute to the highest project cost and drive the project forward. The purpose of this study was to identify the current status and characteristics of the project as a priming project for urban regeneration and to seek desirable alternatives in the future project process. For this purpose, the case of urban regeneration projects in the Chungcheong region was targeted. The results showed that the core projects for each case consisted mainly of projects to develop physical facilities on a relatively large scale. Securing large-scale complex base space and constructing public parking lots are planned as key projects. In addition, based on the cost composition of the priming project, the core project accounted for approximately 80 % of the total project, and the project cost between linked projects does not appear to be relatively well linked in both public and private investment sectors. These findings are expected to help promote substantial urban regeneration projects and enhance efficiency by using them as basic data for urban regeneration projects in the future.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.55-63
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• 2022

In recent years, with the rapid development of large and medium-sized urban rail transit in China, the total operating mileage of high-speed railway and the total number of EMUs(Electric Multiple Units) are rising. The system complexity of high-speed EMU is constantly increasing, which puts forward higher requirements for the safety of equipment and the efficiency of maintenance.At present, the maintenance mode of high-speed EMU in China still adopts the post maintenance method based on planned maintenance and fault maintenance, which leads to insufficient or excessive maintenance, reduces the efficiency of equipment fault handling, and increases the maintenance cost. Based on the intelligent operation and maintenance technology of PHM(prognostics and health management). This thesis builds an integrated PHM platform of "vehicle system-communication system-ground system" by integrating multi-source heterogeneous data of different scenarios of high-speed EMU, and combines the equipment fault mechanism with artificial intelligence algorithms to build a fault prediction model for traction motors of high-speed EMU.Reliable fault prediction and accurate maintenance shall be carried out in advance to ensure safe and efficient operation of high-speed EMU.

• Journal of The Korean Association For Science Education
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• v.41 no.1
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• pp.47-57
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• 2021

This study aims to explore the epistemic goals that pre-service elementary teachers can construct in their biology-related knowledge construction activities, how these goals are constructed, and how the shaping of the knowledge construction activities around the goals was afforded or constrained. The research participants were 26 pre-service teachers, divided into 11 groups of two or three to engage in the activity. Their discussions and products were collected and used as data for this study. The analysis revealed that the teachers constructed three types of epistemic goals: making sense of natural phenomena, proposing the most effective course of action, and proposing solutions to problems based on their causes. Construction of different types of goals depended on the conclusions the pre-service teachers expected to draw based on the explored natural phenomena. It was found that the elicitation of the pre-service teachers' epistemic goals could facilitate their shaping of the knowledge construction activity as an evidence-based justification. The participants planned the construction of mechanistic explanations of natural phenomena with the epistemic goals of 'making sense of natural phenomena' or 'proposing solutions to problems based on their causes.' However, enacting their knowledge construction plans with sophisticated epistemic features was constrained due to the limited resources available. This study can contribute to developing instructional strategies that facilitate learners' epistemic agency and addressing epistemic agency in the development of pre-service teacher education methods.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.2
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• pp.143-150
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• 2021

The recent spread of novel and highly variant pathogenic viruses, including the coronavirus (SARS-CoV-2), has increased the demand for diagnostic testing for rapid confirmation. This has resulted in investigating the functional capability of each space, and preparing facility guidelines to secure the safety of medical technologists. During viral evaluations, there is a requirement of negative pressure facilities along with thread separation, during pre-treatment of samples and before nucleic acid amplification. Space composition therefore needs to be planned by considering unidirectional air flow. This classification of safety management facilities is designated as biosafety level 2, and personal protective equipment is placed accordingly. In case of handling dangerous materials, they need to be carried out of the biosafety cabinet, and sterilizers are required for suitable disposal of infectious agents. A common feature of domestic laboratories is maintenance of the sample pre-treatment space at a negative pressure of -2.5 Pa or less, and arranging separate pre-treatment and reagent preparation spaces during the test process. We believe that the data generated in this study is meaningful, and offers an efficient direction and detailed flow for separation of the inspection process and space functions. Moreover, this study introduces construction of the laboratory by applying the safety management standards.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.344-364
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• 2021

The study explored how two elementary school teachers perceived computational thinking, reflected them into curriculum revision, and taught them in the classroom during longitudinal professional developed program (PDP) for nine months. Computational thinking is a new direction in educational policy-making including science education; therefore we planned to investigate participating teachers' perception of computational thinking to provide their fundamental understandings. Nine meetings, lasting about two hours each, were held with the participating teachers and they developed 11 lesson plans for one unit each, as they formed new understandings about computational thinking. Data were collected through PDP program while two teachers started perceiving computational thinking, revising their curriculum, and implementing it into their class for nine months. The results were as follows; first, elementary school teachers' perception of computational thinking was that the definition of scientific literacy as the purpose of science education was extended, i.e., it refers to scientific literacy to prepare students to be creative problem solvers. Second, STEAM (science, technology, engineering, arts, and mathematics) lessons were divided into two stages; concept formation stage where scientific thinking is emphasized, and concept application, where computational thinking is emphasized. Thirdly, computational thinking is a cognitive thinking process, and ICT (informational and communications technology) is a functional tool. Fourth, computational thinking components appear repeatedly and may not be sequential. Finally, STEAM education can be improved by utilizing computational thinking. Based on this study, we imply that STEAM education can be activated by computational thinking when teachers are equipped with competencies of understanding and implementing computational thinking within the systematic PDPs, which is very essential for newly policies.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.273-284
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• 2022

This study was conducted to examine the practical and educational implications of teachers' operation of the curriculum through science and online classes based on data collected for 4 months from 4 teachers who had experience in science subject online classes among homeroom teachers in the 3rd to 6th grades of elementary school in D city. This study was conducted through narrative inquiry. As a result of conducting interviews and in-depth interviews based on the online class experiences of the Earth Science Unit of the study subjects, and conducting field classes with related documents such as online class-related materials and teacher journals, teachers were more likely to take online classes compared to traditional face-to-face classes. They spent more time preparing and showed difficulties in the process of adapting to the new medium used in online classes. In addition, they demanded the provision of scientific materials produced in a pandemic situation and a teaching platform for smooth class operation. In particular, in the case of experimental classes, there is a burden of completing the planned curriculum, and in a pandemic situation, students felt the need for individual experimental tools for intensive science classes. As a result, it is necessary to introduce a blended learning learning system that combines the advantages of face-to-face and online classes as a new class form for the transition to future education in preparation for the pandemic. Continuous teacher research on the format and online class experience is required.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.469-475
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• 2022

As the recent structure construction is constructed as a large-scale and deep underground excavation in close proximity to the building, the installation of retaining wall and supporters (Struts) has become complicated, and the number of supporters to avoid interference of the structural slab has increased. This construction process becomes a factor that causes an increase in construction joints of a structure, leakage and an increase in wall cracks. In addition, this reduced the durability and workability of the structure and led to an increase in the construction period. This study planned to dismantle the two struts simultaneously as a plan to reduce the construction joints, and corrected the earth pressure by assuming the reaction force value by the initial earth pressure and the measured data as the response ratio. After recalculating the corrected earth pressure through the iterative trial method, it was verified by numerical analysis that simultaneous disassembly of the two struts was possible. As a result of numerical analysis applying the final corrected earth pressure, the measured value for the design reaction force was found to be up to 197%. It was analyzed that this was due to the effect of grouting on the ground and some underestimation of the ground characteristics during design. Based on the result of calculating the corrected earth pressure in consideration of the response ratio performed in this study, it was proved analytically that the improvement of the brace dismantling process is possible. In addition, it was considered that the overall construction period could be shortened by reducing cracks due to leakage and improving workability by reducing construction joints. However, to apply the proposed method of this study, it is judged that sufficient estimations are necessary as there are differences in ground conditions, temporary facilities, and reinforcement methods for each site.

• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.39-47
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• 2009

Recently, the threat of DDoS attacks is increasing and many companies are planned to deploy the DDoS defense solutions in their networks. The DDoS attack usually transmits heavy traffic data to networks or servers and they cannot handle the normal service requests because of running out of resources. Since it is very hard to prevent the DDoS attack beforehand, the strategic plan is very important. In this work, we have conducted modeling and simulation of the DDoS attack by changing the number of servers and estimated the duration that services are available. In this work, the modeling and simulation is conducted using OPNET Modeler. The simulation result can be used as a parameter of trade-off analysis of DDoS defense cost and the service's value. In addition, we have presented a way of estimating the cost effectiveness in deployment of the DDoS defense system.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.377-384
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• 2019

This study was intended to understand the status of dysphagia related knowledge, attitude and nursing performance of nursing staff's in geriatric hospitals, to confirm the correlation among these, and to provide basic resources for dysphagia nursing intervention programs. The 220 subjects were nursing staff's who worked in geriatric hospitals located in G city and N city. For data analysis, The descriptive statistic was used to analyze the subjects' general characteristics, and dysphagia related characteristics, knowledge, attitude and nursing performance degree. For the differences of dysphagia related knowledge, attitude and nursing performance according to the subjects' general characteristics, t-test and ANOVA were used. The correlation of the subjects' knowledge, attitude and nursing performance degree was analyzed with Pearson's correlation coefficient. The score of the subjects' dysphagia related knowledge was average 14.07±2.94, the subjects' dysphagia related attitude was average 3.59±0.39, the subjects' dysphagia nursing performance was 3.10±0.43. dysphagia nursing performance had a significantly positive correlation with dysphagia related knowledge(r=0.295, p=.000) and dysphagia related attitude(r=0.392, p=.000). The above result of the study indicated positive attitude based on accurate knowledge is needed for nursing staff's in geriatric hospitals to improve nursing performance for dysphagia. When education programs for dysphagia are planned in geriatric hospitals, it is necessary to consider knowledge level and attitude simultaneously.