• 한국응급구조학회지
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• 제21권3호
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• pp.35-48
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• 2017

Purpose: The purpose of the study was to investigate the core competency of disaster management of 119 paramedics. Methods: A self-reported questionnaire was completed by 242 paramedics in C area from April 28 to May 12, 2017. The study instrument included general characteristics of the subjects (4 items), disaster experience, recognition, and preparedness (20 items), and importance and performance of disaster management core competency (24 items) by Likert 5-point scale. Data were analyzed using t-test, ANOVA, Pearson's correlation coefficient using IBM SPSS 24.0. Results: The seriousness of personal disaster was 4.02 points and the importance of disaster-related education was 4.28 points. The importance to core competency of disaster management was 4.39 points and the ability to perform core competency was 3.58 points. The seriousness of personal disaster and the importance of disaster-related education were positively correlated (r=.600, p=.000). The importance and ability to perform core competency were positively correlated (r=.389, p=.000). Conclusion: It is necessary to strengthen core competency of disaster management in paramedics who are the first defense line of disaster.

• 융합경영연구
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• 제11권4호
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• pp.31-39
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• 2023

Purpose: This study attempted to systematize a support system that can enhance teaching core competencies by establishing a scale for diagnosing teaching core competencies at University A. Research design, data and methodology : To this end, the first Delphi was conducted With six experts related to university core competency modeling research by extracting factors and designing structured questionnaires through a literature review process that collects and analyzes prior research related to domestic and foreign university teaching competency. The derived questions were diagnosed on 27 professors, and independent sample t-verification and ANOVA were conducted using SPSS 24.0 for analysis by key teaching competency factors. Result: What is the standard suitability of KMO. It was shown as 929 (KMO standard conformity value is close to 1), and Barlett's sphericity verification showed χ2=5773.295, df=1081, p<.It appeared as 001 and confirmed that it was suitable for conducting factor analysis. Conclusions: The core competencies of A University teachers were set based on the educational goals of A University, such as basic teaching competency, creative teaching competency, practical teaching competency, and communication teaching competency. This means that the concept and factors of the core competency of professors are likely to change, and in the end, continuous efforts to upgrade and apply research on core competency of professors are essential to quickly and organically respond to changes in competency required to increase the competitiveness of universities.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3388-3400
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• 2023

Detailed analysis of the neutron pathway through matter inside the nuclear reactor core is exceedingly needed for safety and economic considerations. Due to the constant development of high-performance computing technologies, neutronics analysis using computer codes became more effective and efficient to perform sophisticated neutronics calculations. In this work, a commercial pressurized water reactor (PWR) presented by Virtual Environment for Reactor Applications (VERA) Core Physics Benchmark are modeled and simulated using a high-fidelity simulation of OpenMC code in terms of criticality and fuel pin power distribution. Various problems have been selected from VERA benchmark ranging from a simple two-dimension (2D) pin cell problem to a complex three dimension (3D) full core problem. The development of the code capabilities for reactor physics methods has been implemented to investigate the accuracy and performance of the OpenMC code against VERA SCALE codes. The results of OpenMC code exhibit excellent agreement with VERA results with maximum Root Mean Square Error (RMSE) values of less than 0.04% and 1.3% for the criticality eigenvalues and pin power distributions, respectively. This demonstrates the successful utilization of the OpenMC code as a simulation tool for a whole core analysis. Further works are undergoing on the accuracy of OpenMC simulations for the impact of different fuel types and burnup levels and the analysis of the transient behavior and coupled thermal hydraulic feedback.

• 마이크로전자및패키징학회지
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• 제13권2호
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• pp.1-7
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• 2006

본 논문에서는 솔더 레지스트(solder resist)의 두께와 코어의 물성에 따른 인쇄회로기판의 철의 크기와 형상에 대하여 연구하였다. 인쇄회로기판의 굽힘 변형은 적층되는 재료의 열팽창계수의 차이에 의해 발생한다. 따라서 굽힘 변형의 감소를 위해서는 열팽창계수의 차이가 작은 적층 재료를 사용하는 것이 필요하며, 구조 형상에서도 상면과 하면의 불균일성을 완화시킬 필요가 있다. 또한, 적층 재료에서 코어의 강성을 높여 점의 발생을 억제할 수 있다. 코어를 이루는 복합재료는 적층 순서와 섬유 각에 따른 물성 특성의 방향성에 따라 굽힘과 비틀림이 연성되는 현상을 보이며, 이와 같은 성질을 이용하면 휨을 제어할 수 있다. 본 연구에서는 2층으로 구성된 chip scale package (CSP) 기판의 휨에 대한 연구로, 실험 및 유한 요소해석 툴을 이용하여 개선 결과를 도출하였다.

• Steel and Composite Structures
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• 제26권4호
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• pp.421-437
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• 2018

Free vibration analysis of a three-layered microbeam including an elastic micro-core and two piezo-magnetic face-sheets resting on Pasternak's foundation are studied in this paper. Strain gradient theory is used for size-dependent modeling of microbeam. In addition, three-unknown shear and normal deformations theory is employed for description of displacement field. Hamilton's principle is used for derivation of the governing equations of motion in electro-magneto-mechanical loads. Three micro-length-scale parameters based on strain gradient theory are employed for prediction of vibrational characteristics of structure in micro-scale. The results show that increase of three micro-length-scale parameters leads to significant increase of three natural frequencies especially for increase of second micro-length-scale parameter. This result is according to this fact that stiffness of a micro-scale structure is increased with increase of micro-length-scale parameters.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.829-841
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• 2018

An experiment was conducted for the OECD/NEA ROSA-2 Project using the large-scale test facility (LSTF), which simulated a 17% hot leg intermediate-break loss-of-coolant accident in a pressurized water reactor (PWR). In the LSTF test, core uncovery started simultaneously with liquid level drop in crossover leg downflow-side before loop seal clearing, and water remaining occurred on the upper core plate in the upper plenum. Results of the uncertainty analysis with RELAP5/MOD3.3 code clarified the influences of the combination of multiple uncertain parameters on peak cladding temperature within the defined uncertain ranges. For studying the scaling problems to extrapolate thermal-hydraulic phenomena observed in scaled-down facilities, an experiment was performed for the OECD/NEA PKL-3 Project with the Primarkreislaufe Versuchsanlage (PKL), as a counterpart to a previous LSTF test. The LSTF test simulated a PWR 1% hot leg small-break loss-of-coolant accident with steam generator secondary-side depressurization as an accident management measure and nitrogen gas inflow. Some discrepancies appeared between the LSTF and PKL test results for the primary pressure, the core collapsed liquid level, and the cladding surface temperature probably due to effects of differences between the LSTF and the PKL in configuration, geometry, and volumetric size.

• Nuclear Engineering and Technology
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• 제49권5호
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• pp.928-940
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• 2017

An experiment using the $Prim{\ddot{a}}rkreisl{\ddot{a}}ufe$ Versuchsanlage (PKL) was performed for the OECD/NEA PKL-3 Project as a counterpart to a previous test with the large-scale test facility (LSTF) on a cold leg smallbreak loss-of-coolant accident with an accident management (AM) measure in a pressurized water reactor. Concerning the AM measure, the rate of steam generator (SG) secondary-side depressurization was controlled to achieve a primary depressurization rate of 200 K/h as a common test condition; however, the onset timings of the SG depressurization were different from each other. In both tests, rapid recovery started in the core collapsed liquid level after loop seal clearing, which caused whole core quench. Some discrepancies appeared between the LSTF and PKL test results for the core collapsed liquid level, the cladding surface temperature, and the primary pressure. The RELAP5/MOD3.3 code predicted the overall trends of the major thermal-hydraulic responses observed in the LSTF test well, and indicated a remaining problem in the prediction of primary coolant distribution. Results of uncertainty analysis for the LSTF test clarified the influences of the combination of multiple uncertain parameters on peak cladding temperature within the defined uncertain ranges.

• Structural Engineering and Mechanics
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• 제80권6호
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• pp.727-736
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• 2021

In this work, mathematical modeling of the passive vibration controls of a three-layered sandwich beam under hard excitation is developed. Kelvin-Voigt Viscoelastic model is considered in the core. The formulation is based on the higher-order zig-zag theories where the normal and shear deformations are taken into account only in the viscoelastic core. The dynamic behaviour of the beam is represented by a complex highly nonlinear ordinary differential equation. The method of multiple scales is adopted to solve the analytical frequency-amplitude relationships in the super-harmonic resonance case. Parametric studies are carried out by using HSDT and first-order deformation theory by considering different geometric and material parameters.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.330-338
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• 2023

In this study, impacts of an enhanced-moderation Fuel Assembly (FA) named Truly Optimized PWR (TOP) lattice, which is modified based on the standard 17 × 17 PWR FA, are investigated in a natural circulation Soluble-Boron-Free (SBF) Small Modular Reactor (SMR). Two different TOP lattice designs are considered for the analysis; one is with 1.26 cm pin pitch and 0.38 cm fuel pellet radius, and the other is with 1.40 cm pin pitch and 0.41 cm fuel pellet radius. The NuScale core design is utilized as the base model and assumed to be successfully converted to an SBF core. The analysis is performed following the primary coolant circulation loop, and the reactor is modelled as a single channel for thermal-hydraulic analyses. It is assumed that the ratio of the core pressure drop to the total system pressure drop is around 0.3. The results showed that the reactor power could be increased by 2.5% and 9.8% utilizing 1.26/0.38 cm and 1.40/0.41 cm TOP designs, respectively, under the identical coolant inlet and outlet temperatures as the constraints.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.63-65
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• 2021

보안 SoC (system-on-chip)를 이용한 타원곡선 디지털 서명 알고리듬 (elliptic curve digital signature algorithm; EC-DSA)의 H/W-S/W 통합 구현에 대해 기술한다. 보안 SoC는 Cortex-A53 APU를 CPU로 사용하며, 하드웨어 IP로 설계된 고성능 타원곡선 암호 (high-performance ellipitc curve cryptography; HP-ECC) 코어와 SHA3 (secure hash algorithm 3) 해시 함수 코어가 AXI4-Lite 버스 프로토콜로 연결된다. 고성능 ECC 코어는 12가지의 타원곡선을 지원하며, SHA3 코어는 4가지의 해시 함수를 지원한다. 보안 SoC를 Zynq UltraScale+ MPSoC 디바이스에 구현하여 EC-DSA에 의해 생성된 서명의 유효성을 검증하였다.