• Title/Summary/Keyword: comparative assessment

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Comparative Study of Coupling Factors for Assessment of Low-Frequency Magnetic Field Exposure

  • Shim, Jae-Hoon;Choi, Min-Soo;Jung, Kyu-Jin;Kwon, Jong-Hwa;Byun, Jin-Kyu
    • Journal of Magnetics
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    • v.21 no.4
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    • pp.516-523
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    • 2016
  • In this paper, coupling factors are calculated based on numerical analysis in order to assess various non-uniform low-frequency magnetic field exposure situations. Two types of non-uniform magnetic field sources are considered; circular coil and parallel wires with balanced currents. For each magnetic field source, source current values are determined so that reference magnetic field magnitude can be measured at the specified point on the human model. Various exposure situations are investigated by changing parameters such as the distance between source and human model, radius of circular coil, and the gap between parallel wires. For equivalent human models, prolate spheroid model and simplified human model from IEC 62311 standard are used. The calculated coupling factor values are compared with those obtained by 2D uniform disk human model, and the dependence of coupling factor on the choice of equivalent human model is analyzed.

Validity and Reliability of the Turkish Version of the COVID Stress Scale

  • Demirgoz Bal, Meltem;Dissiz, Melike;Bayri Bingol, Fadime
    • Journal of Korean Academy of Nursing
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    • v.51 no.5
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    • pp.525-536
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    • 2021
  • Purpose: The aim of this study was to assess the Turkish adaptation of the COVID Stress Scale (CSS) on the basis of determining the stress caused by the coronavirus disease (COVID-19) pandemic, and to test its validity and reliability. Methods: The English CSS was translated into Turkish using forward and backward translation. Data were collected online from 360 participants. Construct validity was evaluated using confirmatory factor analysis, exploratory factor analysis, and content validity. Pearson product-moment correlation, Cronbach's alpha reliability coefficient, and test-retest methods were used to evaluate reliability. Results: The Turkish version of the CSS has 36 items consistent with the original scale and has five factors: COVID danger and contamination, socioeconomic consequences of COVID, COVID xenophobia, traumatic stress due to COVID, and compulsive checking for COVID. The construct validity of the Turkish version of the CSS was verified by the adjusted goodness of fit index > .85, and comparative fit index > .95. The content validity index of each item was 91%. The corrected item-total correlations of the scale ranged from .51 to .89. Internal consistency was reliable, with a Cronbach's α of .93. Conclusion: The Turkish version of the CSS is valid and reliable. It can be used as a measurement tool for the assessment of COVID-related stress.

Evaluation of seismic collapse capacity of regular RC frames using nonlinear static procedure

  • Jalilkhani, Maysam;Manafpour, Ali Reza
    • Structural Engineering and Mechanics
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    • v.68 no.6
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    • pp.647-660
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    • 2018
  • The Incremental Dynamic Analysis (IDA) procedure is currently known as a robust tool for estimation of seismic collapse capacity. However, the procedure is time-consuming and requires significant computational efforts. Recently some simplified methods have been developed for rapid estimation of seismic collapse capacity using pushover analysis. However, a comparative review and assessment of these methods is necessary to point out their relative advantages and shortcomings, and to pave the way for their practical use. In this paper, four simplified pushover analysis-based methods are selected and applied on four regular RC intermediate moment-resisting frames with 3, 6, 9 and 12 stories. The accuracy and performance of the different simplified methods in estimating the median seismic collapse capacity are evaluated through comparisons with the results obtained from IDAs. The results show that reliable estimations of the summarized 50% fractile IDA curve are produced using SPO2IDA and MPA-based IDA methods; however, the accuracy of the results for 16% and 84% fractiles is relatively low. The method proposed by Shafei et al. appears to be the most simple and straightforward method which gives rise to good estimates of the median sidesway collapse capacity with minimum computational efforts.

Development of Internal Defect Detector of Automotive Transmission Parts Using Eddy Current (와전류를 이용한 자동차 변속기 부품의 내부결함 검출기 개발)

  • Chai, Yong-Yoong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.3
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    • pp.513-518
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    • 2019
  • The non-destructive testing equipment using an eddy current was developed to check for defect in the vehicle transmission component. A defect master sample was made to test all types of defects that occur in the component and also an eddy current detector was manufactured and used to test and detect all kinds of defects. In addition, testing was held against the actual defective items to investigate the cause and type of defects, and a comparative study was conducted based on results from the examination. The software system of the eddy current detector was developed so that even a non-specialist can make assessment of detect in the component from the test results displayed on the monitor.

Analysis of liberal arts education based on NCS and K-CESA in dental hygiene

  • Yoo, Jin-Ah;Jang, Jong-Hwa
    • Journal of Korean society of Dental Hygiene
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    • v.19 no.5
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    • pp.635-649
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    • 2019
  • Objectives: This literature review seeks to identify the current status of the liberal arts education of dental hygiene majors offered by universities in Korea and the U.S. and provide a comparative analysis of the data on liberal arts education in both countries. Methods: From April 3, 2017 to May 1, 2017, research data on curriculum topics were collected from 60 selected universities. The data were collected from university websites, which also provided the universities' emails and dental hygiene major descriptions. We calculated the descriptive statistics of the variables and performed independent t-tests on the data. Results: In all the domains of the NCS and K-CESA, the dental hygiene major currently offers courses on language and communication and general education, focusing on self-management and development. Few universities offer subjects from other disciplines. Conclusions: Pro-actively exploring strategies is a prerequisite to the systematic operation of standardized dental hygiene education. It is imperative to conduct research consistently on relevant topics, such as teaching methods, general education standards, and connectivity between major subjects and the goals and effects of exposure to a general education.

Shear strength prediction of PRC coupling beams with low span-to-depth ratio

  • Tian, Jianbo;Shen, Dandan;Li, Shen;Jian, Zheng;Liu, Yunhe;Ren, Wengeng
    • Earthquakes and Structures
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    • v.16 no.6
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    • pp.757-769
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    • 2019
  • The seismic performance of a coupled shear wall system is governed by the shear resistances of its coupling beams. The plate-reinforced composite (PRC) coupling beam is a newly developed form of coupling beam that exhibits high deformation and energy dissipation capacities. In this study, the shear capacity of plate-reinforced composite coupling beams was investigated. The shear strengths of PRC coupling beams with low span-to-depth ratios were calculated using a softened strut-and-tie model. In addition, a shear mechanical model and calculating method were established in combination with a multi-strip model. Furthermore, a simplified formula was proposed to calculate the shear strengths of PRC coupling beams with low span-to-depth ratios. An analytical model was proposed based on the force mechanism of the composite coupling beam and was proven to exhibit adequate accuracy when compared with the available test results. The comparative results indicated that the new shear model exhibited more reasonable assessment accuracy and higher reliability. This method included a definite mechanical model and reasonably reflected the failure mechanisms of PRC coupling beams with low span-to-depth ratios not exceeding 2.5.

Models for Internet Traffic Sharing in Computer Network

  • Alrusaini, Othman A.;Shafie, Emad A.;Elgabbani, Badreldin O.S.
    • International Journal of Computer Science & Network Security
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    • v.21 no.8
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    • pp.28-34
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    • 2021
  • Internet Service Providers (ISPs) constantly endeavor to resolve network congestion, in order to provide fast and cheap services to the customers. This study suggests two models based on Markov chain, using three and four access attempts to complete the call. It involves a comparative study of four models to check the relationship between Internet Access sharing traffic, and the possibility of network jamming. The first model is a Markov chain, based on call-by-call attempt, whereas the second is based on two attempts. Models III&IV suggested by the authors are based on the assumption of three and four attempts. The assessment reveals that sometimes by increasing the number of attempts for the same operator, the chances for the customers to complete the call, is also increased due to blocking probabilities. Three and four attempts express the actual relationship between traffic sharing and blocking probability based on Markov using MATLAB tools with initial probability values. The study reflects shouting results compared to I&II models using one and two attempts. The success ratio of the first model is 84.5%, and that of the second is 90.6% to complete the call, whereas models using three and four attempts have 94.95% and 95.12% respectively to complete the call.

Comparative Analysis on the Application of Biotic Indices for Environmental Assessment of a Polluted Stream (Jinwi Stream) (오염하천(진위천)의 환경평가를 위한 생물지수간 적용성 비교분석)

  • Oh, Min Woo;Lee, Ok-Min;Song, Ho-Bok;Park, Sun Jin;Song, Mee Young;Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.27 no.6
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    • pp.760-768
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    • 2011
  • Jinwi Stream is considerably polluted. The urban development in a Jinwi Stream basin can make state of aquatic ecosystem worse. However, researches for aquatic ecosystems in Jinwi Stream are insufficient. In this study, biotic indices of periphytic diatoms (DAIpo and TDI), benthic macroinvertebrates (EPT, KSI and ESB) and fish (IBI) were compared with the annual water quality data. Benthic macroinvertebrates indices showed highly significant correlations with concentrations of organic materials and nutrients, while DAIpo, TDI and IBI showed low correlations with them. In particular, ESB can be considered as an useful indicator that reflects the degree of diversity and abundance of biotic community as well as water quality. In polluted and disturbed streams as Jinwi Stream, DAIpo, TDI and IBI appeared to be not available for evaluating and discriminating the water quality, although they have been known as good indices in general streams.

Comparative assessment of ASCE 7-16 and KBC 2016 for determination of design wind loads for tall buildings

  • Alinejad, Hamidreza;Jeong, Seung Yong;Kang, Thomas H.K.
    • Wind and Structures
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    • v.31 no.6
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    • pp.575-591
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    • 2020
  • Wind load is typically considered as one of the governing design loads acting on a structure. Understanding its nature is essential in evaluation of its action on the structure. Many codes and standards are founded on state of the art knowledge and include step by step procedures to calculate wind loads for various types of structures. One of the most accepted means for calculating wind load is using Gust Load Factor or base bending Moment Gust Load Factor (MGLF), where codes are adjusted based on local data available. Although local data may differ, the general procedure is the same. In this paper, ASCE 7-16 (2017), which is used as the main reference in the U.S., and Korean Building Code (KBC 2016) are compared in evaluation of wind loads. The primary purpose of this paper is to provide insight on each code from a structural engineering perspective. Herein, discussion focuses on where the two codes are compatible and differ. In evaluating the action of wind loads on a building, knowledge of the dynamic properties of the structure is critical. For this study, the design of four figurative high-rise buildings with dual systems was analyzed.

Assessment of maturation stages and the accuracy of age estimation methods in a Turkish population: A comparative study

  • Magat, Guldane;Ozcan, Sevgi
    • Imaging Science in Dentistry
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    • v.52 no.1
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    • pp.83-91
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    • 2022
  • Purpose: This study assessed the associations between chronological age, dental maturation (DM), cervical vertebrae maturation (CVM), and hand-wrist maturation (HWM) in individuals aged 9-19 years. In addition, this study aimed to derive practical methods to evaluate the skeletal age using DM, CVM, or HWM for orthodontic, medical, and forensic purposes and to compare which of these 3 developmental parameters is more accurate for estimating the age of individuals in a Turkish population. Materials and Methods: Panoramic, lateral cephalometric, and hand-wrist radiographs of 284 patients aged 9-19 years were used in this study. The DM, CVM, and HWM stages were determined. The Kolmogorov-Smirnov, kappa, Wilcoxon, Kruskal-Wallis, chi-square, and Spearman correlation tests and simple linear regression analysis were used for statistical analysis. The significance level was 0.05. Results: Statistically significant differences were found between chronological age and DM, chronological age and CVM, and chronological age and HWM in both sexes (P<0.05). DM did not show statistically significant differences according to sex (P>0.05), but CVM and HWM were statistically different between males and females (P<0.05). The DM-estimated age yielded more accurate values than the other methods. Conclusion: All correlations between skeletal and dental stages were statistically significant. Our results showed that there was no statistically significant difference between chronological age and DM-estimated age. Therefore, it can be concluded that DM stages have the potential to be used for legal purposes.