• 한국항공우주학회지
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• 제48권12호
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• pp.987-995
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• 2020

고성능 탑재체들과 자세제어 센서들 간의 정밀정렬은 인공위성의 정확한 자세지향 및 높은 지향 안정성을 위해 필수적이다. 위성 개발사들은 조립 및 시험기간 동안 위성 정렬을 위해 데오드라이트 측정 시스템을 주로 사용한다. 데오드라이트 측정 시 시선 방향 오차, 수평축의 오차, 수직방향 인덱스 오차 그리고 수직축 오차로 인해 측정오차가 발생할 수 있다. 이러한 오차들 뿐 아니라 다수의 데오드라이트를 사용한 측정 시 발생할 수 있는 오차들을 정렬큐브 측정실험을 통해 분석하였다. 정렬큐브 측정실험을 기반으로 정렬측정 정확도를 향상시킬 수 있는 방법이 제안되었고, 측정 결과 위성의 설계 요구조건도 만족시킬 수 있었다.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.233-243
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• 2020

This study aims to assess the impacts of COVID-19 on International Financial Reporting Standards (IFRS), because of the problems associated with changing and amending the financial reports according to the policies established based on the circumstances of the epidemic. The study sample targeted several international financial reports that were amended based on epidemic conditions. The revised financial reporting period provides standardized reporting procedures for financial transactions worldwide despite the pandemic. Therefore, IFRS has been used to reduce challenges in financial reporting by monitoring the duration of social distancing while reporting matters to eliminate confirmed uncertainty and judgment. After analyzing the data obtained through global search engines, the results conducted provided evidence that COVID-19 affects financial reporting in companies around the world. Therefore, companies face difficulty reporting finances based on the challenging environment that the pandemic represents. Besides, IFRS fair value measurements consider the prices that were predicted according to current market values. The contexts of the changing the standards by IFRS to curb the effects of the COVID19 financial reporting was attained through evaluation of the online files that were randomly selected and filtered to obtain valid data.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2002년도 High Temperature Superconductivity Vol.XII
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• pp.22-22
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• 2002

• 부모자녀건강학회지
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• 제17권1호
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• pp.37-45
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• 2014

Purpose: This study aimed to review measurements of environmental health behavior and assess the construct validity of Environmental Health Engagement Profile (EHEP) through confirmatory factor analysis. Methods: The literature review was performed for selection of measurements. Confirmatory factor analysis with AMOS 19.0 was used for validation of EHEP. Results: The model fitness was not appropriate in the one-factor model; $x^2=91.11$ (df=5, p<.001), Comparative Fit Index (CFI)=8.19, Non Normed Fit Index (NNFI)=6.39, and Root Mean Square Error of Approximation (RMSEA)=0.20. The model fitness was appropriate in the two-factor model; $x^2=3.19$ (df=1, p=.074), CFI=9.95, NNFI= 9.71, RMSEA=0.07. A modification of scale was found to be the most suitable for use in the investigation of environmental health behavior. Conclusion: This study confirms that a two-factor model underlies the concept of environmental health behavior. The review of measurements can help nurses and researchers to assess the environmental health behaviors.

• Journal of Welding and Joining
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• 제33권1호
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• pp.30-34
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• 2015

Residual stresses are inherently introduced into the engineering components during manufacturing including rolling, forging, bending and welding processes. Excessive residual stresses are known to be detrimental to the proper integrity and performance of components. Neutron diffraction has become a well-established technique for the determination of residual stresses in welds. The deep penetration capability of neutrons into most metallic materials makes neutron diffraction a powerful tool for the residual stress measurements through the thickness of the weld specimen. Furthermore, the unique volume-averaged bulk characteristic of the scattering beam and mapping capability in three dimensions is suitable for the engineering purpose. In this presentation, the neutron diffraction measurements of the residual stresses will be introduced and measurement results will highlighted in thick weld plates.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.77-84
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• 1997

Cone calorimeter measurements can be used for the calculation of effective material properties, which can be used as input parameters in modeling of fire. Main parameter measured in Cone calorimeter is heat release rate. Some other parameters as time to ignition, effective heat of combustion, mass loss rate or total heat released is also measured in Cone calorimeter. Total heat released is important from the point of view of total energy available in material in Fire situation. Cone calorimeter. measurements were done on several wood species (oak, beech, spruce, poplar). Measurements were provided at external irradiances 30, 50 and 65 ㎾/$m_2$ in horizontal orientation. Heat release rate data were evaluated and compared as a function of external irradiance for various species of wood. furthermore the influence of external irradiance on effective heat of combustion and total heat release was also evaluated for the period of flame combustion.

• 한국군사과학기술학회지
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• 제11권3호
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• pp.76-88
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• 2008

The purpose of the research is to propose an earned-value indicator for technical performance measurements of an ongoing defense R&D project and the associated measurement, analysis and the implementation process for data collection and usages. Furthermore, the study demonstrates the evidences of benefits and validity of the proposed approach through the enabling tool development and its application examples.

• Structural Monitoring and Maintenance
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• 제2권4호
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• pp.357-382
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• 2015

This paper provides an overview of the use of different Distributed Optical Fiber Sensor systems (DOFSs) to perform Structural Health Monitoring (SHM) in the specific case of civil engineering structures. Nowadays, there are several methods available for extracting distributed measurements from optical fiber, and their use have to be according with the aims of the SHM performance. The continuous-in-space data is the common advantage of the different DOFSs over other conventional health monitoring systems and, depending on the particular characteristics of each DOFS, a global and/or local health structural evaluation is possible with different accuracy. Firstly, the fundamentals of different DOFSs and their principal advantages and disadvantages are presented. Then, laboratory and field tests using different DOFSs systems to measure strain in structural elements and civil structures are presented and discussed. Finally, based on the current applications, conclusions and future trends of DOFSs in SHM in civil structures are proposed.

• Structural Engineering and Mechanics
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• 제41권1호
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• pp.83-94
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• 2012

Assessment of a monumental concrete arch bridge with a total length of 210 meters having three major spans of 30 meters and a height of 65 meters, which is located in an earthquake-prone region in southern part of the country is presented in this study. Three-dimensional finite element model of the bridge was generated using a commercially available general finite element analysis software and based on the outcomes of a series of in-depth acceleration measurements that were conducted on-site, the model was refined. By using the structural parameters obtained from the dynamic and the static tests, calibrated model of the bridge structure was obtained and this model was used for necessary calculations regarding structural assessment and evaluation.

• Advances in aircraft and spacecraft science
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• 제3권3호
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• pp.259-269
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• 2016

In this work results from an underwater experiment on flow-induced noise in the interior of a towed body generated from a surrounding turbulent boundary layer are presented. The measurements were performed with a towed body under open sea conditions at towing depths below 100 m and towing speeds ranging from 2.4 m/s to 6.2 m/s (4 kn to 12 kn). Focus is given in the experiments to the relation between (outer) wall pressure fluctuations and the (inner) hydroacoustic near-field on the reverse side of a flat plate. The plate configuration consists of a sandwich structure with an (thick) outer polyurethane layer supported by an inner thin layer from fibre-reinforced plastics. Parameters of the turbulent boundary layer are estimated in order to analyse scaling relations of wall-pressure fluctuations, interior hydroacoustic noise, and the reduction of pressure fluctuations through the plate.