• Title/Summary/Keyword: bias reference

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Does minimally invasive canal preparation provide higher fracture resistance of endodontically treated teeth? A systematic review of in vitro studies

  • Sila Nur Usta;Emmanuel Joao Nogueira Leal Silva;Seda Falakaloglu;Mustafa Gundogar
    • Restorative Dentistry and Endodontics
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    • v.48 no.4
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    • pp.34.1-34.12
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    • 2023
  • This systematic review aimed to investigate whether minimally invasive root canal preparation ensures higher fracture resistance compared to conventional root canal preparation in endodontically treated teeth (ETT). A comprehensive search strategy was conducted on the "PubMed, Web of Science, and Scopus" databases, alongside reference and hand searches, with language restrictions applied. Two independent reviews selected pertinent laboratory studies that explored the effect of minimally invasive root canal preparation on fracture resistance, in comparison to larger preparation counterparts. The quality of the studies was assessed, and the risk of bias was categorized as low, moderate, or high. The electronic search yielded a total of 1,767 articles. After applying eligibility criteria, 8 studies were included. Given the low methodological quality of these studies and the large variability of fracture resistance values, the impact of reduced apical size and/or taper on the fracture resistance of the ETT can be considered uncertain. This systematic review could not reveal sufficient evidence regarding the effect of minimally invasive preparation on increasing fracture resistance of ETT, primarily due to the inherent limitations of the studies and the moderate risk of bias.

The applicability study and validation of TULIP code for full energy range spectrum

  • Wenjie Chen;Xianan Du;Rong Wang;Youqi Zheng;Yongping Wang;Hongchun Wu
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4518-4526
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    • 2023
  • NECP-SARAX is a neutronics analysis code system for advanced reactor developed by Nuclear Engineering Computational Physics Laboratory of Xi'an Jiaotong University. In past few years, improvements have been implemented in TULIP code which is the cross-section generation module of NECP-SARAX, including the treatment of resonance interface, considering the self-shielding effect in non-resonance energy range, hyperfine group method and nuclear library with thermal scattering law. Previous studies show that NECP-SARAX has high performance in both fast and thermal spectrum system analysis. The accuracy of TULIP code in fast and thermal spectrum system analysis is demonstrated preliminarily. However, a systematic verification and validation is still necessary. In order to validate the applicability of TULIP code for full energy range, 147 fast spectrum critical experiment benchmarks and 170 thermal spectrum critical experiment benchmarks were selected from ICSBEP and used for analysis. The keff bias between TULIP code and reference value is less than 300 pcm for all fast spectrum benchmarks. And that bias keeps within 200 pcm for thermal spectrum benchmarks with neutron-moderating materials such as polyethylene, beryllium oxide, etc. The numerical results indicate that TULIP code has good performance for the analysis of fast and thermal spectrum system.

The development of statistical methods for retrieving MODIS missing data: Mean bias, regressions analysis and local variation method (MODIS 손실 자료 복원을 위한 통계적 방법 개발: 평균 편차 방법, 회귀 분석 방법과 지역 변동 방법)

  • Kim, Min Wook;Yi, Jonghyuk;Park, Yeon Gu;Song, Junghyun
    • Journal of Satellite, Information and Communications
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    • v.11 no.4
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    • pp.94-101
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    • 2016
  • Satellite data for remote sensing technology has limitations, especially with visible range sensor, cloud and/or other environmental factors cause missing data. In this study, using land surface temperature data from the MODerate resolution Imaging Spectro-radiometer(MODIS), we developed retrieving methods for satellite missing data and developed three methods; mean bias, regression analysis and local variation method. These methods used the previous day data as reference data. In order to validate these methods, we selected a specific measurement ratio using artificial missing data from 2014 to 2015. The local variation method showed low accuracy with root mean square error(RMSE) more than 2 K in some cases, and the regression analysis method showed reliable results in most cases with small RMSE values, 1.13 K, approximately. RMSE with the mean bias method was similar to RMSE with the regression analysis method, 1.32 K, approximately.

Antimicrobial efficacy of QMix on Enterococcus faecalis infected root canals: a systematic review of in vitro studies

  • Lim, Benjamin Syek Hur;Parolia, Abhishek;Chia, Margaret Soo Yee;Jayaraman, Jayakumar;Nagendrababu, Venkateshbabu
    • Restorative Dentistry and Endodontics
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    • v.45 no.2
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    • pp.23.1-23.12
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    • 2020
  • Objectives: This study aimed to summarize the outcome of in vitro studies comparing the antibacterial effectiveness of QMix with other irrigants against Enterococcus faecalis. Materials and Methods: The research question was developed by using population, intervention, comparison, outcome, and study design framework. The literature search was performed using 3 electronic databases: PubMed, Scopus, and EBSCOhost until October 2019. The additional hand search was performed from the reference list of the eligible studies. The risk of bias of the studies was independently appraised using the revised Cochrane Risk of Bias tool (RoB 2.0). Results: Fourteen studies were included in this systematic review. The overall risk of bias for the selected studies was moderate. QMix was found to have a higher antimicrobial activity compared to 2% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA), 2% chlorhexidine (CHX), mixture of tetracycline isonomer, an acid and a detergent (MTAD), 0.2% Cetrimide, SilverSol/H2O2, HYBENX, and grape seed extract (GSE). QMix had higher antibacterial efficacy compared to NaOCl, only when used for a longer time (10 minutes) and with higher volume (above 3 mL). Conclusions: QMix has higher antibacterial activity than 17% EDTA, 2% CHX, MTAD, 0.2% Cetrimide, SilverSol/H2O2, HYBENX, GSE and NaOCl with lower concentration. To improve the effectiveness, QMix is to use for a longer time and at a higher volume.

Correlation between gray values of cone-beam computed tomograms and Hounsfield units of computed tomograms: A systematic review and meta-analysis

  • Selvaraj, Abirami;Jain, Ravindra Kumar;Nagi, Ravleen;Balasubramaniam, Arthi
    • Imaging Science in Dentistry
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    • v.52 no.2
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    • pp.133-140
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    • 2022
  • Purpose: The aim of this review was to systematically analyze the available literature on the correlation between the gray values (GVs) of cone-beam computed tomography (CBCT) and the Hounsfield units (HUs) of computed tomography (CT) for assessing bone mineral density. Materials and Methods: A literature search was carried out in PubMed, Cochrane Library, Google Scholar, Scopus, and LILACS for studies published through September 2021. In vitro, in vivo, and animal studies that analyzed the correlations GVs of CBCT and HUs of CT were included in this review. The review was prepared according to the PRISMA checklist for systematic reviews, and the risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. A quantitative analysis was performed using a fixed-effects model. Results: The literature search identified a total of 5,955 studies, of which 14 studies were included for the qualitative analysis and 2 studies for the quantitative analysis. A positive correlation was observed between the GVs of CBCT and HUs of CT. Out of the 14 studies, 100% had low risks of bias for the domains of patient selection, index test, and reference standards, while 95% of studies had a low risk of bias for the domain of flow and timing. The fixed-effects meta-analysis performed for Pearson correlation coefficients between CBCT and CT showed a moderate positive correlation (r=0.669; 95% CI, 0.388 to 0.836; P<0.05). Conclusion: The available evidence showed a positive correlation between the GVs of CBCT and HUs of CT.

Design and Amplitude Modulation Characteristics with Bias of Class J Power Amplifier for CSB (CSB용 J급 전력증폭기 설계 및 바이어스에 따른 진폭 변조 특성)

  • Su-kyung Kim;Kyung-Heon Koo
    • Journal of Advanced Navigation Technology
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    • v.27 no.6
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    • pp.849-854
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    • 2023
  • In this paper, a high-efficiency power amplifier was designed by applying the operating point Class J using LDMOS(laterally diffused metal oxide semiconductor) and optimizing the output matching circuit so that the second harmonic impedance becomes the reactance impedance. The designed power amplifier has a frequency of 108 ~ 110 MHz, Characteristics of PAE(power added efficiency) is 71.5% at PSAT output (54.5 dBm), 55.5% at P1dB output (51.5 dBm), and 24.38% at 45 dBm. The CSB(carrier with sideband) amplifier, which is the reference signal in the spatial modulation method, has an operating output of 45 dBm ~ 35 dBm, and linear SDM(sum in the depth of modulation) characteristics(40% ± 0.3%) were obtained. We measure the characteristics in amplitude modulation according to the bias operating point of the power amplifier for CSB and propose the optimal operating point to obtain linear modulation characteristics.

The Contextual Effects on Pronoun Reaolution (대명사의 참조관계 처리시의 맥락의 역할)

  • 방희정
    • Korean Journal of Cognitive Science
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    • v.2 no.2
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    • pp.279-307
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    • 1990
  • The present research inverstigates the nature of contextual effects on pronoun reference resolution during text comprehesion.Through three experiments,this research examines how various contextuall informations influence on reference resolution and interact with syntactic variables.In experiment 1,the local context was controlled by biasing the pronoun-sentence context towards a certain preceding referent.The lexical decision time and the forced choice time for the correct referent were measured.The results showed that the local contexts have clear effect on reference resolution.The effects of syntactic ambiguity were also observed though the local context was biased towards a certain referent noun.In experiment 2,the global context effect was examined by introducing the text-thematic context in a preceding sentence while keeping the following pronoun-sentence context neutral.The results showed that the global thematic context bias towards a subject or object in a preceding sentence entails a faster response time than the thematically neutral context.In experiment 3,another aspects of context effects were inverstigated by manipulating the consistency of the preceding thematic context with the following pronoun-sentence context.The results showed that the lexical decision responses and forced referent choice responses were faster when the prethematic context and the post-anaphoric context match than when they mismatch.In sum,the overall results of three experiments of this research indicates that context has a clear effect on pronoun reference resolution during text comprehension.

Developing GPS Code Multipath Grid Map (CMGM) of Domestic Reference Station (국내 기준국의 GPS 코드 다중경로오차 격자지도 생성)

  • Gyu Min Kim;Gimin Kim;Chandeok Park
    • Journal of Positioning, Navigation, and Timing
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    • v.13 no.1
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    • pp.85-92
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    • 2024
  • This study develops a Global Positioning System (GPS) Code Multipath Grid Map (CMGM) of each individual domestic reference station from the extracted code multipath of measurement data. Multipath corresponds to signal reflection/refraction caused by obstacles around the receiver antenna, and it is a major source of error that cannot be eliminated by differencing. From the receiver-independent exchange format (RINEX) data for two days, the associated code multipath of a satellite tracking arc is extracted. These code multipath data go through bias correction and interpolation to yield the CMGM with respect to the azimuth and elevation angles. The effect of the CMGM on multipath mitigation is then quantitatively analyzed to improve the Root Mean Square (RMS) of averaged pseudo multipath. Furthermore, the single point positioning (SPP) accuracy is analyzed in terms of the RMS of the horizontal and vertical errors. During two weeks in February 2023, the RMSs of the averaged pseudo multipath for five reference stations decreased by about 40% on average after CMGM application. Also, the SPP accuracies increased by about 7% for horizontal errors and about 10% for vertical errors on average after CMGM application. The overall quantitative analysis indicates that the proposed approach will reduce the convergence time of Differential Global Navigation Satellite System (DGNSS), Real-Time Kinematic (RTK), and Precise Point Positioning (PPP)-RTK correction information in real-time to use measurement data whose code multipath is corrected and mitigated by the CMGM.

Determination of $^{226}Ra$ Isotope in the Leachate around Phosphogypsum Stack Using Ethylenediaminetetraacetic Acid (EDTA) (Ethylenediaminetetraacetic acid (EDTA)를 이용한 인산석고 야적장 침출수 중의 $^{226}Ra$ 분석법 개발)

  • Kim, Geun-Ho;Kim, Yong-Jae;Chang, Byung-Uck
    • Journal of Radiation Protection and Research
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    • v.36 no.4
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    • pp.223-229
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    • 2011
  • Ba is the most useful element to get the $Ba(Ra)SO_4$ precipitate. However, when the high concentrations of ions such as sulfate, calcium are existed in the leachate of phosphogypsum stack, it is difficult to get the $Ba(Ra)SO_4$ precipitate. Since this reason, the developed method for the Ba coprecipitate using EDTA was performed to determine the $^{226}Ra$ concentration in the high sulfate sample. The average concentration of $^{226}Ra$ in a leachate of phosphogypsum using this method was 0.102 $Bq{\cdot}kg^{-1}$ and the minimal detectable activity is 3.4 $mBq{\cdot}kg^{-1}$. The $mBq{\cdot}kg^{-1}$ method was 0.102 $Bq{\cdot}kg^{-1}$ and the minimal detectable activity is 3.4 $mBq{\cdot}kg^{-1}$. The $^{226}Ra$ stock solution and the CRM (Certified Reference Material) were analyzed to verify this method. In analyzed $^{226}Ra$ stock solution, bias with added concentration was approximately 1% and the correlation curve between $^{226}Ra$ concentration in simulated standard sample and measured $^{226}Ra$ concentration showed good agreement with a correlation coefficient ($R^2$) of 0.99. In analyzed CRM, maximum bias with reference value was 5.8% (k=1) and the analytical results were in good agreement with the reference value.

Automated Measurement of Native T1 and Extracellular Volume Fraction in Cardiac Magnetic Resonance Imaging Using a Commercially Available Deep Learning Algorithm

  • Suyon Chang;Kyunghwa Han;Suji Lee;Young Joong Yang;Pan Ki Kim;Byoung Wook Choi;Young Joo Suh
    • Korean Journal of Radiology
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    • v.23 no.12
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    • pp.1251-1259
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    • 2022
  • Objective: T1 mapping provides valuable information regarding cardiomyopathies. Manual drawing is time consuming and prone to subjective errors. Therefore, this study aimed to test a DL algorithm for the automated measurement of native T1 and extracellular volume (ECV) fractions in cardiac magnetic resonance (CMR) imaging with a temporally separated dataset. Materials and Methods: CMR images obtained for 95 participants (mean age ± standard deviation, 54.5 ± 15.2 years), including 36 left ventricular hypertrophy (12 hypertrophic cardiomyopathy, 12 Fabry disease, and 12 amyloidosis), 32 dilated cardiomyopathy, and 27 healthy volunteers, were included. A commercial deep learning (DL) algorithm based on 2D U-net (Myomics-T1 software, version 1.0.0) was used for the automated analysis of T1 maps. Four radiologists, as study readers, performed manual analysis. The reference standard was the consensus result of the manual analysis by two additional expert readers. The segmentation performance of the DL algorithm and the correlation and agreement between the automated measurement and the reference standard were assessed. Interobserver agreement among the four radiologists was analyzed. Results: DL successfully segmented the myocardium in 99.3% of slices in the native T1 map and 89.8% of slices in the post-T1 map with Dice similarity coefficients of 0.86 ± 0.05 and 0.74 ± 0.17, respectively. Native T1 and ECV showed strong correlation and agreement between DL and the reference: for T1, r = 0.967 (95% confidence interval [CI], 0.951-0.978) and bias of 9.5 msec (95% limits of agreement [LOA], -23.6-42.6 msec); for ECV, r = 0.987 (95% CI, 0.980-0.991) and bias of 0.7% (95% LOA, -2.8%-4.2%) on per-subject basis. Agreements between DL and each of the four radiologists were excellent (intraclass correlation coefficient [ICC] of 0.98-0.99 for both native T1 and ECV), comparable to the pairwise agreement between the radiologists (ICC of 0.97-1.00 and 0.99-1.00 for native T1 and ECV, respectively). Conclusion: The DL algorithm allowed automated T1 and ECV measurements comparable to those of radiologists.