• Title/Summary/Keyword: absolute values

Search Result 787, Processing Time 0.027 seconds

Comparison of absolute and relative thermal QST thresholds In the orofacial region of the young Korean women (젊은 한국 여성의 구강안면영역에서 절대적 온도역치와 상대적 온도역치간의 비교)

  • Kim, Ki-Suk
    • Journal of Oral Medicine and Pain
    • /
    • v.38 no.4
    • /
    • pp.367-372
    • /
    • 2013
  • To diagnose sensory nerve damage, patient values for thermal stimuli as quantitative sensory test (QST) can be compared with the values of the general population (absolute reference data) or to values measured at contralateral unaffected side (relative reference data). It is well know that relative reference data are more sensitive for detecting sensory abnormality than absolute reference data. However it is still lack of the studies for comparisons between relative and absolute data. This study aimed to evaluate the validity of relative reference data and compare the sensitivities of the two approaches in the orofacial region. In 19 young Korean women as normal subjects, quantitative somatosensory thermotest were done in the forehead, cheek, mentum, lower lip and tongue tip bilaterally. After we get the standard deviations (SD) of average reference data and relative reference data, the ratios SD absolute data/SD relative data were calculated. Our study showed that relative reference data for side to side comparisons in the same patient have the high ratios than the absolute reference data, i.e. the side to side comparisons with relative reference data exhibit gain in sensitivity in assessment of sensory abnormality.

Feasibility study of using triple-energy CT images for improving stopping power estimation

  • Yejin Kim;Jin Sung Kim ;Seungryong Cho
    • Nuclear Engineering and Technology
    • /
    • v.55 no.4
    • /
    • pp.1342-1349
    • /
    • 2023
  • The planning accuracy of charged particle therapy (CPT) is subject to the accuracy of stopping power (SP) estimation. In this study, we propose a method of deriving a pseudo-triple-energy CT (pTECT) that can be achievable in the existing dual-energy CT (DECT) systems for better SP estimation. In order to remove the direct effect of errors in CT values, relative CT values according to three scanning voltage settings were used. CT values of each tissue substitute phantom were measured to show the non-linearity of the values thereby suggesting the absolute difference and ratio of CT values as parameters for SP estimation. Electron density, effective atomic number (EAN), mean excitation energy and SP were calculated based on these parameters. Two of conventional methods were implemented and compared to the proposed pTECT method in terms of residuals, absolute error and root-mean-square-error (RMSE). The proposed method outperformed the comparison methods in every evaluation metrics. Especially, the estimation error for EAN and mean excitation using pTECT were converging to zero. In this proof-of-concept study, we showed the feasibility of using three CT values for accurate SP estimation. Our suggested pTECT method indicates potential clinical utility of spectral CT imaging for CPT planning.

Auditory Perception Experiment on Attribute of Road Traffic Noise Causing Annoyance with Identical Linear Sound Pressure Level (동일한 선형 음압 레벨의 도로교통소음의 성가심 유발 인자에 관한 연구)

  • An, Jang-Ho;Schang, Seo-Il;Ko, J.H.;Chun, Hyung-Jun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2006.11a
    • /
    • pp.641-648
    • /
    • 2006
  • This study investigates which sound quality indices except SPL raise annoyance response. For investigation, auditory perception experiments for road traffic noise with identical linear SPL were performed by Paired Comparison Method. The numerical results of a Paired Comparison experiment express relative preference about annoyance. So that these relative preference scores are to be correlated to sound quality indices, which are absolute, a transformation is required to go from the relative domain to an absolute and linear scale of preference. The results of the transformation will be the 'merit values,' which quantifies the annoyance(in this case) of the road traffic noise on a linear scale. Using multiple regression, a formula is established that can calculate predicted merit values. Furthermore, This investigation offers a method selecting sound samples that represent various sound quality indices values to use experiment.

  • PDF

Differences in Vowel Duration Due to the Underlying Voicing of the Following Coda Stop in Russian and English: Native and Non-native Values

  • Oh, Eun-Jin
    • Speech Sciences
    • /
    • v.13 no.3
    • /
    • pp.19-33
    • /
    • 2006
  • This study explores whether Russian, known to have a process of syllable-final devoicing, reveals differences in vowel duration as a function of the underlying voicing of the coda stop. This paper also examines whether non-native speakers of Russian and English learn typical L2 values in vowel duration. The results indicate that vowels in Russian have a slightly longer mean duration before a voiced stop than before a voiceless stop (a mean difference of 9.52 ms), but in most cases the differences did not exhibit statistical significance. In English the mean difference was 60.05 ms, and the differences were in most cases statistically significant. All native Russian speakers of English produced larger absolute differences in vowel duration for English than for Russian, and all native English speakers of Russian produced smaller absolute differences for Russian than for English. More experienced learners seemed to achieve more native-like values of vowel duration than less experienced learners did, suggesting that learning occurs gradually as the learners gain more experience with the L2.

  • PDF

Can We Rely on GLOBOCAN and GBD Cancer Estimates? Case Study of Lung Cancer Incidence and Mortality Rates and Trends in Iran

  • Vardanjani, Hossein Molavi;Heidari, Mohammad;Hadipour, Maryam
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.7
    • /
    • pp.3265-3269
    • /
    • 2016
  • Background: Around half of input data in the global burden of disease cancer collaboration (GBD-CC) and GLOBOCAN projects come from low quality sources, mainly from developing countries. This may lead to loss of precision in estimates. Our question was: Are the absolute values and trends of the GBD-CC and GLOBOCAN estimates for lung cancer (LC) in Iran consistent with available statistics?. Materials and Methods: Incidence and mortality statistics were extracted from national reports (N.IRs & N.MRs) and GBD-CC (GBD-incidence & mortality) and GLOBOCAN databases for 1990-2013 where available. Trends were analyzed and absolute values and annual percentage changes (APCs) were estimated and compared. Incompleteness of case ascertainment at the Iranian national cancer registry and Iranian national civil registration was assessed for better understanding. Results: Trends of N.IRs were significantly rising for males (APC: 19.4; 95% CI: 12.5-26.7) and females (23.2; 16.0-30.8). Trends of GBD-incidence were stable for males (-0.2; -1.5-1.1) and females (-1.0; -2.3-0.4). Absolute N.IRs were less than GBD-incidence steadily except for 2009. Trend of N.MRs was increasing up to 2004, but stable thereafter. Trends of GBD-mortality were also stable. Absolute N.MRs were less than GBD-mortality for years up to 2003 and more than GBD-mortality since 2005. The estimates of GLOBOCAN were more than N.IRs and N.MRs. Conclusions: The GBD-CC and GLOBOCAN values for LC in Iran are underestimates. Generation of data quality indices to present along with country specific estimates is highly recommended.

Hybrid navigation parameter estimation from aerial image sequence (항공영상을 이용한 하이브리드 영상 항법 변수 추출)

  • 심동규;정상용;이도형;박래홍;김린철;이상욱
    • Journal of the Korean Institute of Telematics and Electronics S
    • /
    • v.35S no.2
    • /
    • pp.146-156
    • /
    • 1998
  • Thispapr proposes hybrid navigation parameter estimation using sequential aerial images. The proposed navigation parameter estimation system is composed of two parts: relative position estimation and absolute position estimation. the relative position estimation recursively computes the current velocity and absolute position estimation. The relative position estimation recursively computes the current velocity and position of an aircraft by accumulating navigation parameters extracted from two succesive aerial images. Simple accumulation of parameter values decreases reliability of the extracted parameters as an aircraft goes on navigating. therefore absolute position estimation is required to compensate for position error generated in the relative position step. The absolute position estimation algorithm combining image matching and digital elevation model(DEM) matching is presented. Computer simulation with real aerial image sequences shows the efficiency of the proposed hybrial algorithm.

  • PDF

Recovery of spectral absolute acceleration and spectral relative velocity from their pseudo-spectral counterparts

  • Papagiannopoulos, George A.;Hatzigeorgiou, George D.;Beskos, Dimitri E.
    • Earthquakes and Structures
    • /
    • v.4 no.5
    • /
    • pp.489-508
    • /
    • 2013
  • Design spectra for damping ratios higher than 5% have several important applications in the design of earthquake-resistant structures. These highly damped spectra are usually derived from a 5%-damped reference pseudo-acceleration spectrum by using a damping modification factor. In cases of high damping, the absolute acceleration and the relative velocity spectra instead of the pseudo-acceleration and the pseudo-velocity spectra should be used. This paper elaborates on the recovery of spectral absolute acceleration and spectral relative velocity from their pseudo-spectral counterparts. This is accomplished with the aid of correction factors obtained through extensive parametric studies, which come out to be functions of period and damping ratio.

A Missing Value Replacement Method for Agricultural Meteorological Data Using Bayesian Spatio-Temporal Model (농업기상 결측치 보정을 위한 통계적 시공간모형)

  • Park, Dain;Yoon, Sanghoo
    • Journal of Environmental Science International
    • /
    • v.27 no.7
    • /
    • pp.499-507
    • /
    • 2018
  • Agricultural meteorological information is an important resource that affects farmers' income, food security, and agricultural conditions. Thus, such data are used in various fields that are responsible for planning, enforcing, and evaluating agricultural policies. The meteorological information obtained from automatic weather observation systems operated by rural development agencies contains missing values owing to temporary mechanical or communication deficiencies. It is known that missing values lead to reduction in the reliability and validity of the model. In this study, the hierarchical Bayesian spatio-temporal model suggests replacements for missing values because the meteorological information includes spatio-temporal correlation. The prior distribution is very important in the Bayesian approach. However, we found a problem where the spatial decay parameter was not converged through the trace plot. A suitable spatial decay parameter, estimated on the bias of root-mean-square error (RMSE), which was determined to be the difference between the predicted and observed values. The latitude, longitude, and altitude were considered as covariates. The estimated spatial decay parameters were 0.041 and 0.039, for the spatio-temporal model with latitude and longitude and for latitude, longitude, and altitude, respectively. The posterior distributions were stable after the spatial decay parameter was fixed. root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and bias were calculated for model validation. Finally, the missing values were generated using the independent Gaussian process model.

Estimation of Mass Discrimination Factor for a Wide Range of m/z by Argon Artificial Isotope Mixtures and NF3 Gas

  • Min, Deullae;Lee, Jin Bok;Lee, Christopher;Lee, Dong Soo;Kim, Jin Seog
    • Bulletin of the Korean Chemical Society
    • /
    • v.35 no.8
    • /
    • pp.2403-2409
    • /
    • 2014
  • Absolute isotope ratio is a critical constituent in determination of atomic weight. To measure the absolute isotope ratio using a mass spectrometer, mass discrimination factor, $f_{MD}$, is needed to convert measured isotope ratio to real isotope ratio of gas molecules. If the $f_{MD}$ could be predicted, absolute isotope ratio of a chemical species would be measureable in absence of its enriched isotope pure materials or isotope references. This work employed gravimetrically prepared isotope mixtures of argon (Ar) to obtain $f_{MD}$ at m/z of 40 in the magnetic sector type gas mass spectrometer (gas/MS). Besides, we compare the nitrogen isotope ratio of nitrogen trifluoride ($NF_3$) with that of nitrogen molecule ($N_2$) decomposed from the same $NF_3$ thermally in order to identify the difference of $f_{MD}$ values in extensive m/z region from 28 to 71. Our result shows that $f_{MD}$ at m/z 40 was $-0.044%{\pm}0.017%$ (k = 1) from measurement of Ar artificial isotope mixtures. The $f_{MD}$ difference in the range of m/z from 28 to 71 is observed $-0.12%{\pm}0.14%$ from $NF_3$ and $N_2$. From combination of this work and reported $f_{MD}$ values by another team, IRMM, if $f_{MD}$ of $-0.16%{\pm}0.14%$ is applied to isotope ratio measurement from $N_2$ to $SF_6$, we can determine absolute isotope ratio within relative uncertainty of 0.2 %.

Implementation of AAPM's TG-51 Protocol on Co-60 MRI-Guided Radiation Therapy System

  • Cho, Jin Dong;Park, Jong Min;Choi, Chang Heon;Kim, Jung-in;Wu, Hong-Gyun;Park, So-Yeon
    • Progress in Medical Physics
    • /
    • v.28 no.4
    • /
    • pp.190-196
    • /
    • 2017
  • For the $ViewRay^{(R)}$ system (ViewRay Inc., Cleveland, OH, USA) which is representative of magnetic resonance (MR) guided radiotherapy machine, it is important to evaluate effectiveness of AAPM's TG-51 protocol and the effect of the magnetic field on absolute dosimetry. In order to measure the absolute dose, MR-compatible chamber and water phantom system manufactured in this study were used. The materials of the water phantom system were plastic of polymethyl methacrylate (PMMA) and non-ferrous materials. Due to the inherent feature of the $ViewRay^{(R)}$, all Co-60 sources are not located at gantry angle of $0^{\circ}$ while being located at gantry angle of $90^{\circ}$. For this reason, absolute dosimetry was performed based on the measurements in solid water phantom (SWP) and water which determine the SWP to water correction factor. For evaluation of output constancy with gantry angle, measurements were made with ionization chamber inserted in cylindrical water-equivalent phantom. For measured doses in water, the values of dose deviation according to a reference dose of 200 cGy for Head 1, Head 2 and Head 3 were -0.27%, -0.45% and -0.22%, respectively. For measured doses in SWP, the values of dose deviation according to a reference dose of 200 cGy for Head 1, Head 2 and Head 3 were -1.91%, -2.07% and -1.84%, respectively. All values of dose measured in SWP tended to be less than those measured in water by -1.63%. With the reference gantry angles of $0^{\circ}$ and $90^{\circ}$, the maximum values of deviation for Head 1, Head 2 and Head 3 were 0.48%, 1.06% and 0.40%, respectively. The measurement agreement is within the range of results obtainable for conventional treatment machines. The low strength of the magnetic field does not affect dose measurements. Using the SWP to water correction factor, absolute doses for $ViewRay^{(R)}$ system can be measured.