• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.523-530
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• 2014

Machine material and structural strain are critical factors for appraising mechanical properties and safety. Particularly in three and four-point bending tests, which appraise the deflection and flexural strain of an object due to external force, measurements are made by the crosshead movement or deflection meter of a universal testing machine. The Digital Image Correlation (DIC) method is one of the non-contact measurement methods. It uses the image analyzing method that compares the reference image with the deformed image for measuring the displacement and strain of the objects caused by external force. Accordingly, the advantage of this method is that the object's surface roughness, shape, and temperature have little influence. However, its disadvantage is that it requires extensive time to compare the reference image with the deformed image for measuring the displacement and strain. In this study, an algorithm is developed for DIC that can improve the speed of image analysis for measuring the deflection and strain of an object caused by a three-point bending load. To implement this algorithm for improving the speed of image analysis, LabVIEW 2010 was used. Furthermore, to evaluate the accuracy of the developed fast correlation algorithm, the deflection of an aluminum specimen under a three-point bending load was measured by using the universal test machine and DIC measurement system.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.73-83
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• 2022

The purpose of this paper was to identify a method to improve received noise in a specific frequency band, caused by RF radiation signals during aircraft operation. The communication equipment of the aircraft is critical to the performance and safety of the flight mission, as it is responsible for the function of internal and external communications. Noise-free, clean communication quality, as well as transmission and receiving functions have to be implemented. Thus, the cause analysis of the reception noise in a specific frequency band, was analyzed through trouble shooting. The receiving noise due to the RF radiation signal emitted from the subsystem unit inside the aircraft, was improved by shielding with a CAP with electroless nickel plating applied. Additionally, the measurement and verification results of the improvement method are also described.

• Health Policy and Management
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• v.32 no.3
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• pp.304-316
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• 2022

Background: As prevention of coronavirus disease 2019 (COVID-19) transmission in healthcare settings has become a critical component in its effective management, COVID-19 specific infection prevention and control (IPC) guidelines were developed and implemented by numerous countries. Although largely based on the current evidence-base, guidelines show much heterogeneity, as they are influenced by respective health system capacities, epidemiological risk, and socioeconomic status. This study aims to analyze the variations and concurrences of these guidelines to draw policy implications for COVID-19 response and future guidelines development. Methods: The contents of the COVID-19 IPC guidelines were analyzed using the categories and codes developed based on "World Health Organization guidelines on core components." Data analysis involved reviewing, appraising and synthesizing data from guidelines, which were then arranged into categories and codes. Selection of countries was based on the country income level, availability of COVID-19 specific IPC guideline developed at a national or district level. Results: The guidelines particularly agreed on IPC measures regarding application of standard precautions and providing information to patients and visitors, monitoring and audit of IPC activities and staff illnesses, and management of built environment/equipments. The guidelines showed considerable differences in certain components, such as workplace safety measures and criteria for discontinuation of precautions. Several guidelines also contained unique features which enabled a more systematic response to COVID-19. Conclusion: The guidelines generally complied with the current evidence-based COVID-19 management but also revealed variances stemming from differences in local health system capacity. Several unique features should be considered for benchmark in future guidelines development.

• Journal of Aerospace System Engineering
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• v.16 no.4
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• pp.35-44
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• 2022

The study on the wake vortex behavior during the aircraft's take-off and landing flight phase is critical to the flight safety of the aircraft, following close behind and the economy of the airport. The study on the wake vortex behavior should include the understanding of the ground effect on the behavior of the multiple wake vortices, generated from aircraft during the take-off and landing flight phase. In thia study, numerical schemes that can consider the ground effect were devised, by applying a vorticity boundary condition and an image method into the existing two-dimensional Fourier-spectral method. The present method was validated by comparing the present results, with the computed and measured data in the published literature. It was shown that the present method can predict the generation and behavior of the secondary vortex near the ground with reasonable accuracy. In future, the effect of the atmospheric conditions such as the stratification and the wind shear on the behavior of the vortex pair will be studied.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.5
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• pp.203-211
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• 2023

For fast-built and safe precast concrete (PC) construction, the dry mechanical splicing method is a critical technique that enables a self-sustaining system (SSS) during construction with no temporary support and minimizes onsite jobs. However, due to limited experimental evidence, traditional wet splicing methods are still dominantly adopted in the domestic precast industry. For PC beam-column connections, the current design code requires achieving emulative connection performances and corresponding structural integrity to be comparable with typical reinforced concrete (RC) systems with monolithic connections. To this end, this study conducted the standard material tests on mechanical splices to check their satisfactory performance as the Type 2 mechanical splice specified in the ACI 318 code. Two PC beam-column connection specimens with dry mechanical splices and an RC control specimen as the special moment frame were subsequently fabricated and tested under lateral reversed cyclic loadings. Test results showed that the seismic performances of all the PC specimens were fully comparable to the RC specimen in terms of strength, stiffness, energy dissipation, drift capacity, and failure mode, and their hysteresis responses showed a mitigated pinching effect compared to the control RC specimen. The seismic performances of the PC and RC specimens were evaluated quantitatively based on the ACI 374 report, and it appeared that all the test specimens fully satisfied the seismic performance criteria as a code-compliant special moment frame system.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.100-107
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• 2023

Open-phase fault in a Permanent Magnet Synchronous Motor (PMSM) occurs due to disconnection of phases of motor windings or inverter switch failures. When an open-phase occurs, it leads to the generation of torque ripples and vibrations in the motor, which can have a critical impact on the safety of the vehicle (including aircraft) using a PMSM as an actuator. Therefore, rapid fault detection and classification are essential. This paper proposes a classification method for detecting open-phase faults and locating fault positions in a PMSM used in aircraft applications. The proposed approach uses an Extended Kalman Filter for fault diagnosis, and it subsequently classifies faults using a Multiple Model filter.

• Women's Health Nursing
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• v.30 no.2
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• pp.101-106
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• 2024

This paper discusses the implications of the birth notification system and the Protected Birth Act in Korea. Aiming to prevent infanticide and abandonment of infants, the law will enter into force on July 19, 2024 in South Korea. The birth notification system mandates that both parents and the head of the medical institution where the birth occurred must report the event. In parallel, the Protected Birth Act will be implemented, allowing pregnant women in crisis who wish to remain anonymous, the option to give birth outside of a hospital setting in a way that safeguards the life and health of the child. However, many issues are being raised in Korean society in advance of the implementation of the Protected Birth Act. There is widespread concern that the Protected Birth Act fails to protect either women or children, especially as it raises issues regarding the need for legislation to protect children with disabilities and to address gaps for migrant women and children. This paper examines the gender and healthcare issues relating to the Protected Birth Act, focusing on women's health and human rights. The Act continues to perpetuate discrimination against out-of-wedlock pregnancies and upholds the ideology of the traditional family model. Furthermore, the legislative process did not address protective measures for the various reasons behind child abandonment. Critical issues such as women's autonomy, safe pregnancy termination, and paternal responsibility in childbirth are also notably absent. However, with the Act set to take effect soon, it is crucial for healthcare providers to comprehend the rationale and procedures associated with birth notification and the Protected Birth Act, and to prepare for its nationwide implementation. The law defines the socially vulnerable as its main beneficiaries, and it is necessary to strengthen social safety nets to improve their access to healthcare, eliminate prejudice and discrimination against out-of-wedlock pregnancies, and embrace the diversity of our society. We eagerly anticipate future discussions on gender and healthcare issues, as well as amendments to the law that reflect real-world circumstances to provide genuine protection for pregnant women in crisis and their infants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.626-631
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• 2018

An emergency evacuation support system is used to maintain evacuation routes by pressurizing a space inside screens. In cases of fire, it is important to understand the thermal distributions in the tunnel for preventing system failure. In this study, we numerically investigated the effect of fire on an emergency evacuation support system in a large fabric store with some fire scenarios with different combustibles. The critical temperature for system failures was assumed to be $200^{\circ}C$. As a result, the highest temperature was predicted in the ceiling part due to the effect of a ceiling jet, and the fire safety of the screen was secured at distances of 20 to 30 m according to the heat release rate. To prevent the inflow of smoke into the system, it is necessary to maintain more than 5 Pa if positive pressure inside the smoke screen. The results of this study could be useful for designing an emergency evacuation support system.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.31-39
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• 2016

Background: It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. Materials and methods: A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. Results and discussion: A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. Conclusion: The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.91-97
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• 2017

The purpose of the study was to investigate the fire fighter image through disaster movies in Korea and other countries. From September 1 to 7, 2016, the movie search methods were carried out using movie title and key words via Wikipedia and various internet web sites from 1903 to 2016. The results included that the fire fighters had been considered as the precious person of volunteer activity regarding fire suppression, investigators, and self-sacrifice. Through the convergence and integration review of the disaster movie, this research suggested that the national based establishment of the welfare and safety system for the posttraumatic stress disorder(PTSD) and critical incident stress management(CISM) education program. This study will provide the basic data for the development of welfare and safety management for the fire fighters and let the people know the sacrifice of the fire fighters including the motto, "First in and the last out".