• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.2
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• pp.101-111
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• 2021

Two different types of shear-friction tests were classified by external loadings and referred to as a push-off and a pull-off test. In a pull-off test, a tension force is applied in the transverse direction of the test specimen to produce a shear stress at the shear plane. This paper presents a method to evaluate shear transfer strengths of uncracked pull-off specimens. The method is based on the compression field theory and different constitutive laws are applied in some ways to gain accurate shear strengths considering softening effects of concrete struts based on Modified Compression Field Theory (MCFT) and Softened Truss Model (STM). The validity of the proposed method is examined by applying to some selected test specimens in literatures and results are compared with the predicted values. A general agreement is observed between predicted and measured values at ultimate loading stages in initially uncracked pull-off test specimens. A shear strength evaluation formula considering the effective compressive strength of a concrete strut was proposed, and the applicability of the proposed formula was verified by comparing with the experimental results in the literature.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.2
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• pp.82-89
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• 2021

This study proposes a DAB two-stage series structure with insulated bidirectional DC-DC converter for two-way power transfer between the renewable energy of high voltages (1 kV and above). The proposed circuit transforms the existing DAB converter into a two-stage series structure to reduce the pressure in the switch. The problem of power imbalance occurring in the design of the DAB converter second-stage series is improved by applying the cell balancing method circuit and the common mode coupled inductor using an external flying capacitor instead of reflecting the existing improvement measures, voltage balance control, and inductor current control. In addition, a no-load supercharging sequence is proposed in high voltages and high-speed switching by using the fixed duty output method. This study presents the analysis results through the structure of the proposed circuit, the principle of improving the power imbalance problem, and simulations. Prototypes were manufactured to meet the specifications of input/output voltage of 1700 V, maximum load of 65 kW, and switching frequency of 51kHz, and the validity of the topology was verified using the experimental results and efficiency data.

• Journal of Engineering Education Research
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• v.21 no.6
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• pp.99-107
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• 2018

The purpose of this study is to establish and propose educational vision of chemical engineering field in order to search for academic identity and future education direction in chemical engineering field. In order to achieve this research purpose, we investigate the literature and data on the vision, educational goals, and curriculum of the department of chemical engineering in domestic and foreign universities. We also analyze the SWOT of internal and external environmental factors respectively. The validity of the proposal was verified through delphi survey with delphi panels and the vision was developed by revising and improving upon the opinions of professionals. The vision is comprised of the value and mission of learning, the educational purpose, and the educational goal. The first stage is value and mission of chemical engineering. The educational purposes and the educational goals are divided into 'Department of Chemical Engineering' and 'Department of Chemical and Biological Engineering'. The application of the educational vision of chemical engineering field is as follows. First, we expect that the vision to be a valuable, philosophical, and theoretical basis for establishing educational objectives and goals in the field of chemical engineering. Hopefully, it will be used as a general education goal for the top-level education. Second, we hope that the vision will be used to develop customized vision, customized educational purpose, and educational goals that reflect the characteristics of region, departments, graduates, and educational needs in the field of chemical engineering. Finally, we hope that these results will be the starting point to discuss the educational vision in the department of chemical engineering.

• Journal of Home Health Care Nursing
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• v.27 no.3
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• pp.294-305
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• 2020

Purpose: The aim of this study was to examine the preliminary effects of applying a developed web-based video education program in patients with cancer receiving chemotherapy. Methods: A one-group pre-post test design was used. The web-based video education program to prevent infection consisted of 5 subjects. The program was confirmed to be valid by an expert group of doctors and nurses. Convenience sampling of 23 subjects was performed to evaluate the effectiveness of the web-based video education program. Data were analyzed based on nonparametric statistics using SPSS 25.0 software. Results: Per the results of the study, knowledge and self-management behavior of infection prevention significantly improved after application of the program; however, there was no significant difference in self-efficacy. Conclusion: It was confirmed that the web-based video education program is effective to improve the knowledge and self-management behavior of infection prevention. However, as a preliminary study, this study did not have external validity. Therefore, it is necessary to verify the effectiveness of the program through randomized controlled trials and confirm the true infection prevention effect that was not considered in this research design.

• Archives of Plastic Surgery
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• v.49 no.3
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• pp.397-404
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• 2022

Background Excessive use of corticosteroids therapy along with gross immunocompromised conditions in the novel coronavirus disease 2019 (COVID-19) pandemic has raised the risks of contracting opportunistic fungal infections. Here, we describe our experience with the implementation of a surgical protocol to treat and reconstruct rhino-orbital-cerebral mucormycosis. Methods A retrospective review of our prospectively maintained database was conducted on consecutive patients diagnosed with mucormycosis undergoing immediate reconstruction utilizing our "Mucormycosis Management Protocol." All patients included in this study underwent reconstruction after recovering from COVID-19. Wide local excision was performed in all cases removing all suspected and edematous tissue. Reconstruction was done primarily after clear margins were achieved on clinical assessment under a cover of injectable liposomal amphotericin B. Results Fourteen patients were included. The average age was 43.6 years and follow-up was 24.3 days. Thirteen patients had been admitted for inpatient care of COVID-19. Steroid therapy was implemented for 2 weeks in 11 patients and for 3 weeks in 3 patients. Eight patients (57.1%) had a maxillectomy and mucosal lining resection with/without skin excision, and six patients (42.8%) underwent maxillectomy and wide tissue excision (maxillectomy and partial zygomatic resection, orbital exenteration, orbital floor resection, nose debridement, or skull base debridement). Anterolateral thigh (ALT) flaps were used to cover defects in all patients. All flaps survived. No major or minor complications occurred. No recurrence of mucormycosis was noted. Conclusion The approach presented in this study indicates that immediate reconstruction is safe and reliable in cases when appropriate tissue resection is accomplished. Further studies are required to verify the external validity of these findings.

• Korean Journal of Clinical Pharmacy
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• v.32 no.3
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• pp.260-269
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• 2022

Background: Comprehensive medication management is essential to achieve safe and optimal drug use for the elderly in long-term care facilities (LTCF). This study aimed to develop eligibility criteria for "Comprehensive medication management program in LTCF" using the RAND/UCLA Appropriateness Method (RAM). Furthermore, we attempted to estimate the number of beneficiaries who met the criteria by analyzing the National Health Insurance claims data. Methods: Twelve criteria were selected initially. We composed a panel of 14 experts with expertise in long-term care. We conducted two survey rounds to reach a consensus. Rating for appropriateness and decision regarding agreement were applied per RAM. We analyzed the National Health Insurance data to estimate the number of LTCF residents who met each eligibility criterion. Results: Of the 11 items agreed upon, ten items were determined to be appropriate. In 2018, 83.6% of 165,994 residents of LTCF met one or more eligibility criteria. The largest number of subjects met the "New residents of LTCF" criterion, followed by "Take high-alert drugs" and "Chronic excessive polypharmacy." Since the items evaluated as most appropriate by the expert panel and those with a large number of subjects were similar, we confirmed the external validity of our criteria. Conclusion: It is worth noting that this is the first attempt to establish the eligibility criteria for medication management in LTCF. Further preliminary research is needed to identify the selected subjects' drug-related problems and revise the criteria according to the results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.2
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• pp.626-643
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• 2023

As mobile forensics has emerged as an essential technique, the demand for technology development, education and training is increasing, wherein images are used. Academic societies in South Korea and national institutions in the US and the UK are leading the Mobile Forensic Image development. However, compared with disks, images developed in a mobile environment are few cases and have less active research, causing a waste of time, money, and manpower. Mobile Forensic Images are also difficult to trust owing to insufficient verification processes. Additionally, in South Korea, there are legal issues involving the Telecommunications Business Act and the Act on the Protection and Use of Location Information. Therefore, in this study, we requested a review of a standard model for the development of Mobile Forensic Image from experts and designed an 11-step development model. The steps of the model are as follows: a. setting of design directions, b. scenario design, c. selection of analysis techniques, d. review of legal issues, e. creation of virtual information, f. configuring system settings, g. performing imaging as per scenarios, h. Developing a checklist, i. internal verification, j. external verification, and k. confirmation of validity. Finally, we identified the differences between the mobile and disk environments and discussed the institutional efforts of South Korea. This study will also provide a guideline for the development of professional quality verification and proficiency tests as well as technology and talent-nurturing tools. We propose a method that can be used as a guide to secure pan-national trust in forensic examiners and tools. We expect this study to strengthen the mobile forensics capabilities of forensic examiners and researchers. This research will be used for the verification and evaluation of individuals and institutions, contributing to national security, eventually.

• Journal of the Korea Society of Computer and Information
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• v.28 no.9
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• pp.167-176
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• 2023

In this paper, we designed and implemented a graph assessment module that can evaluate graphs in an programming assessment system based on text and numbers. The assessment method of the graph assessment module is self-evaluation that outputs two graphs generated by codes submitted by learners and by answers, automatic-evaluation that converts each graph image into an array, and gives feedback if it is wrong. The data used to generate the graph can be inputted directly or used from external data, and the method of generatng graph that can be evaluated is MATLAB style in matplotlib, and the graph shape that can be evaluated is presented in mathematics and curriculum. Through expert review, it was confirmed that the content elements of the assessment module, the possibility of learning, and the validity of the learner's needs were met. The graph assessment module developed in this study has expanded the evaluation area of the programming automatic asssessment system and is expected to help students learn data visualization.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.269-276
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• 2022

The robustness of a supply chain (i.e., the ability to cope with external and internal disruptions and disturbances) becomes more critical in ensuring the success of a construction project because the supply chain of today's construction project includes more and diverse suppliers. Previous studies indicate that topological features of the supply chain critically affect its robustness, but there is still a great challenge in characterizing and quantifying the impact of network topological features on its robustness. In this context, this study aims to identify network measures that characterize topological features of the supply chain and evaluate their impact on the robustness of the supply chain. Network centrality measures that are commonly used in assessing topological features in social network analysis are identified. Their validity in capturing the impact on the robustness of the supply chain was evaluated through an experiment using randomly generated networks and their simulations. Among those network centrality measures, the PageRank centrality and its standard deviation are found to have the strongest association with the robustness of the network, with a positive correlation coefficient of 0.6 at the node level and 0.74 at the network level. The findings in this study allows for the evaluation of the supply chain network's robustness based only on its topological design, thereby enabling practitioners to better design a robust supply chain and easily identify vulnerable links in their supply chains.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.717-724
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• 2023

An essential step in evaluating and comparing the performance of two passive radiation dosimeter types, thermosluminescent (TLD) and optically stimulated luminescence (OSL), used by workers in environments with ionizing radiation for individual radiological monitoring and control of external exposure at various times (cumulative dose for 1 month), is to compare the measured dose accuracy, energy response, and coefficient of variation. In fact this performance study consists in determining the accuracy of both R(10) and R(0.07) which are considered as the ratios of the measured dose (Hp(10) or Hp(0.07)) to the delivered dose (Hp(10) or Hp(0.07)) for each photon energy. The validity of the results of this test is based on the acceptance limits of the ICRP and the international standard IEC-62387. The relative energy response used is normalized to the ¹³⁷Cs 662 keV energy to find which energy response is closest to the ideal case, and the coefficient of variation that allows to determine the statistical fluctuation of the Hp(10) and Hp(0.07) doses. The results of the accuracy test for the OSL and TLD dosimeters are acceptable because they fall within the ICRP limits. For the energy response, the OSL performs better than the TLD for Hp(10) and Hp(0.07), and for the coefficient of variation, the OSL satisfies the requirements of ISO 62387 for both Hp(10) and Hp(0.07), while the TLD satisfies these requirements only for the measurement of Hp (0.07).