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Development of a mapping function ("crosswalk") for the conversion of scores between the Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI)

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EUROPEAN SPINE JOURNAL 2022年第12期31卷 3337-3346页

作者： Mannion, A. F. Elfering, A. Fekete, T. F. Pizones, J. Pellise, F. Pearson, A. M. Lurie, J. D. Porchet, F. Aghayev, E. Vila-Casademunt, A. Mariaux, F. Richner-Wunderlin, S. Kleinstuck, F. S. Loibl, M. Perez-Grueso, F. S. Obeid, I Alanay, A. Vengust, R. Jeszenszky, D. Haschtmann, D. Schulthess Klin Dept Teaching Res & Dev Spine Ctr Div Lengghalde 2 CH-8008 Zurich Switzerland Univ Bern Inst Psychol Bern Switzerland Schulthess Klin Dept Spine Surg & Neurosurg Zurich Switzerland Univ Hosp La Paz Dept Orthoped Surg Spine Unit Madrid Spain Hosp Valle De Hebron Spine Unit Barcelona Spain Dartmouth Hitchcock Med Ctr Lebanon NH 03766 USA EUROSPINE Spine Tango Task Force Uster Switzerland Pellegrin Univ Hosp Spine Surg Unit Bordeaux France Acibadem Mehmet Ali Aydinlar Univ Dept Orthoped & Traumatol Istanbul Turkey Ljubljana Univ Med Ctr Dept Orthoped Surg Ljubljana Slovenia

Introduction The Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI) are two commonly used self-rating outcome instruments in patients with lumbar spinal disorders. No formal crosswalk between them exists that would otherwise allow the scores of one to be interpreted in terms of the other. We aimed to create such a mapping function. Methods We performed a secondary analysis of ODI and COMI data previously collected from 3324 patients (57 +/- 17y;60.3% female) at baseline and 1y after surgical or conservative treatment. Correlations between scores and Cohen's kappa for agreement (kappa) regarding achievement of the minimal clinically important change (MCIC) score on each instrument (ODI, 12.8 points;COMI, 2.2 points) were calculated, and regression models were built. The latter were tested for accuracy in an independent set of registry data from 634 patients (60 +/- 15y;56.8% female). Results All pairs of measures were significantly positively correlated (baseline, 0.73;1y follow-up (FU), 0.84;change-scores, 0.73). MCIC for COMI was achieved in 53.9% patients and for ODI, in 52.4%, with 78% agreement on an individual basis (kappa = 0.56). Standard errors for the regression slopes and intercepts were low, indicating excellent prediction at the group level, but root mean square residuals (reflecting individual error) were relatively high. ODI was predicted as COMI x 7.13-4.20 (at baseline), COMI x 6.34 + 2.67 (at FU) and COMI x 5.18 + 1.92 (for change-score);COMI was predicted as ODI x 0.075 + 3.64 (baseline), ODI x 0.113 + 0.96 (FU), and ODI x 0.102 + 1.10 (change-score). ICCs were 0.63-0.87 for derived versus actual scores. Conclusion Predictions at the group level were very good and met standards justifying the pooling of data. However, we caution against using individual values for treatment decisions, e.g. attempting to monitor patients over time, first with one instrument and then with the other, due to the lower statistical precision at th

关键词： Oswestry Disability Index (ODI) Core Outcome Measures Index (COMI) Spinal disorders Crosswalk mapping function

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A new computerized ionosphere tomography model using the mapping function and an application to the study of seismic-ionosphere disturbance

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JOURNAL OF GEODESY 2016年第8期90卷 741-755页

作者： Kong, Jian Yao, Yibin Liu, Lei Zhai, Changzhi Wang, Zemin Wuhan Univ Chinese Antarctic Ctr Surveying & Mapping Wuhan 430079 Peoples R China Wuhan Univ Sch Geodesy & Geomat Wuhan 430079 Peoples R China

A new algorithm for ionosphere tomography using the mapping function is proposed in this paper. First, the newsolution splits the integration process into four layers along the observation ray, and then, the single-layer model (SLM) is applied to each integration part using a mapping function. Next, the model parameters are estimated layer by layer with the Kalman filtering method by introducing the scale factor (SF). to solve the ill-posed problem. Finally, the inversed images of different layers are combined into the final CIT image. We utilized simulated data from 23 IGS GPS stations around Europe to verify the estimation accuracy of the new algorithm;the results show that the new CIT model has better accuracy than the SLMin dense data areas and the CIT residuals are more closely grouped. The stability of the new algorithm is discussed by analyzing model accuracy under different error levels (the max errors are 5TECU, 10TECU, 15TECU, respectively). In addition, the key preset parameter, SF., which is given by the International Reference Ionosphere model (IRI2012). The experiment is designed to test the sensitivity of the new algorithm to SF variations. The results show that the IRI2012 is capable of providing initial SF values. Also in this paper, the seismic-ionosphere disturbance (SID) of the 2011 Japan earthquake is studied using the new CIT algorithm. Combined with the TEC time sequence of Sat. 15, we find that the SID occurrence time and reaction area are highly related to the main shock time and epicenter. According to CIT images, there is a clear vertical electron density upward movement (from the 150-km layer to the 450-km layer) during this SID event;however, the peak value areas in the different layers were different, which means that the horizontal movement velocity is not consistent among the layers. The potential physical triggering mechanism is also discussed in this paper. Compared with the SLM, the RMS of the new CIT model is improved by 16.78%, w

关键词： mapping function Computerized ionosphere tomography Kalman filtering Seismic-ionosphere disturbance TEC variation sequence Electric field effect

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Application of a disease-specific mapping function to estimate utility gains with effective treatment of schizophrenia

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Health and Quality of Life Outcomes 2005年第1期3卷 1-8页

作者： Lenert, Leslie A. Rupnow, Marcia F.T. Elnitsky, Christine Veterans Administration San Diego Health Care System San Diego CA United States University of California San Diego CA United States Janssen Medical Affairs L.L.C. Titusville NJ United States Health Services Research and Development Service Department of Veteran Affairs Washington DC United States

Background: Most tools for estimating utilities use clinical trial data from general health status models, such as the 36-Item Short-Form Health Survey (SF-36). A disease-specific model may be more appropriate. The objective of this study was to apply a disease-specific utility mapping function for schizophrenia to data from a large, 1-year, open-label study of long-acting risperidone and to compare its performance with an SF-36-based utility mapping function. Methods: Patients with schizophrenia or schizoaffective disorder by DSM-IV criteria received 25, 50, or 75 mg long-acting risperidone every 2 weeks for 12 months. The Positive and Negative Syndrome Scale (PANSS) and SF-36 were used to assess efficacy and health-related quality of life. Movement disorder severity was measured using the Extrapyramidal Symptom Rating Scale (ESRS);data concerning other common adverse effects (orthostatic hypotension, weight gain) were collected. Transforms were applied to estimate utilities. Results: A total of 474 patients completed the study. Long-acting risperidone treatment was associated with a utility gain of 0.051 using the disease-specific function. The estimated gain using an SF-36-based mapping function was smaller: 0.0285. Estimates of gains were only weakly correlated (r=0.2). Because of differences in scaling and variance, the requisite sample size for a randomized trial to confirm observed effects is much smaller for the disease-specific mapping function (156 versus 672 total subjects). Conclusions: Application of a disease-specific mapping function was feasible. Differences in scaling and precision suggest the clinically based mapping function has greater power than the SF-36-based measure to detect differences in utility. © 2005 Lenert et al;licensee BioMed Central Ltd.

关键词： Schizophrenia Risperidone mapping function Schizoaffective Disorder Utility Gain

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A New mapping function in Table-Mounted Eye Tracker

A New Mapping Function in Table-Mounted Eye Tracker

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International Conference on Optical Instruments and Technology (OIT) at the Topical Meeting on Optoelectronic Imaging/Spectroscopy and Signal Processing Technology

作者： Tong, Qinqin Xiao, Hua Qiu, Jian Luo, Kaiqing Peng, Li Han, Peng South China Normal Univ Sch Phys & Telecommun Engn Guangzhou Guangdong Peoples R China

ISBN: (数字)9781510617520

ISBN: (纸本)9781510617520;9781510617513

Eye tracker is a new apparatus of human-computer interaction, which has caught much attention in recent years. Eye tracking technology is to obtain the current subject's "visual attention (gaze)" direction by using mechanical, electronic, optical, image processing and other means of detection. While the mapping function is one of the key technology of the image processing, and is also the determination of the accuracy of the whole eye tracker system. In this paper, we present a new mapping model based on the relationship among the eyes, the camera and the screen that the eye gazed. Firstly, according to the geometrical relationship among the eyes, the camera and the screen, the framework of mapping function between the pupil center and the screen coordinate is constructed. Secondly, in order to simplify the vectors inversion of the mapping function, the coordinate of the eyes, the camera and screen was modeled by the coaxial model systems. In order to verify the mapping function, corresponding experiment was implemented. It is also compared with the traditional quadratic polynomial function. And the results show that our approach can improve the accuracy of the determination of the gazing point. Comparing with other methods, this mapping function is simple and valid.

关键词： Eye Tracker visual attention mapping function

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A Method Based on Interpolation mapping function For InSAR Image Registration

A Method Based on Interpolation Mapping Function For InSAR I...

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IEEE International Conference on Electronic Information and Communication Technology (ICEICT)

作者： He, Ke Chen, Yong-guang Jia, Xin Ran, Da Equipment Acad Beijing Peoples R China Beijing Inst Tracking & Telecommun Technol Beijing Peoples R China China TH Satellite Ctr Beijing Peoples R China

ISBN: (纸本)9781509007295

Image registration process principally consists of two steps, i.e. tie patches mapping and resampling of the slave image. Accurate and efficient mapping of master and slave image samples is of crucial importance since it guarantees the quality of the follow-up products, which is the focus of this paper. Specifically an automatic hierarchical approach has been adopted in the registration of SAR images, i.e. the coarse registration is firstly realized by the performance of crosscorrelation to achieve pixel scale accuracy, then the interpolation of the shifts of a series of localized tie patches is carried out to align the slave image to the master image with sub-pixel accuracy. Simulations demonstrate that, compared with method that are based on biquadratic equations solved by the Least Squares(LS) approach, the proposed method provides a better resolution than that of LS approach for steep scenes and meanwhile it makes a drastic reduction of the calculation load. RADARSAT2 images are finally used to prove its validity and reliability.

关键词： Image registration Synthetic Aperture Radar(SAR) interferometry SAR(InSAR) mapping function cross-correlation

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Modeling Research on Tropospheric Delay mapping function

Modeling Research on Tropospheric Delay Mapping Function

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2023 Cross Strait Radio Science and Wireless Technology Conference, CSRSWTC 2023

作者： Li, Ruoyu Lin, Leke Chen, Xiangming Zhang, Qiang China Research Institute of Radiowave Propagation Qingdao China School of Physics Xidian University Xi'an China

ISBN: (纸本)9798350358971

Due to the increasing demands for atmospheric refraction in radio systems, the investigation of atmospheric propagation errors has emerged as a primary approach to enhancing system accuracy. The mapping function plays a crucial role in accurately converting zenith direction delay to the signal transmission path direction, thus serving as a vital parameter for analyzing tropospheric delays. To enhance the accuracy of slant path delay in radio systems, this study utilizes meteorological sounding data from the Qingdao station in 2022, including pressure, temperature, humidity, and other variables. By employing the parameter fitting method, a rational mapping function model is established. The results demonstrate that the new mapping function model outperforms traditional models in calculating slant path delays, particularly in reducing error in the wet term delay. This improvement carries significant implications for enhancing the accuracy of radio systems. © 2023 IEEE.

关键词： atmospheric refraction mapping function slant path delay zenith delay

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TMF: A GNSS Tropospheric mapping function for the Asymmetrical Neutral Atmosphere

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REMOTE SENSING 2021年第13期13卷

作者： Zhang, Di Guo, Jiming Fang, Tianye Wei, Na Mei, Wensheng Zhou, Lv Yang, Fei Zhao, Yinzhi Wuhan Univ Sch Geodesy & Geomat 129 Luoyu Rd Wuhan 430079 Peoples R China Wuhan Univ GNSS Res Ctr 129 Luoyu Rd Wuhan 430079 Peoples R China Guilin Univ Technol Coll Geomat & Geoinformat Guilin 541004 Peoples R China China Univ Min & Technol Beijing Coll Geosci & Surveying Engn Beijing 100083 Peoples R China Beijing Key Lab Urban Spatial Informat Engn Beijing 100038 Peoples R China

Tropospheric mapping function plays a vital role in the high precision Global Navigation Satellites Systems (GNSS) data processing for positioning. However, most mapping functions are derived under the assumption that atmospheric refractivity is spherically symmetric. In this paper, the pressure, temperature, and humidity fields of ERA5 data with the highest spatio-temporal resolution available from the European Centre for Medium-range Weather Forecast (ECMWF) were utilized to compute ray-traced delays by the software WHURT. Results reveal the universal asymmetry of the hydrostatic and wet tropospheric delays. To accurately represent these highly variable delays, a new mapping function that depends on elevation and azimuth angles-Tilting mapping function (TMF)-was applied. The basic idea is to assume an angle between the tropospheric zenith direction and the geometric zenith direction. Ray-traced delays served as the reference values. TMF coefficients were fitted by Levenberg-Marquardt nonlinear least-squares method. Comparisons demonstrate that the TMF can improve the MF-derived slant delay's accuracy by 73%, 54% and 29% at the 5 degrees elevation angle, against mapping functions based on the VMF3 concept, without, with a total and separate estimation of gradients, respectively. If all coefficients of a symmetric mapping function are determined together with gradients by a least-square fit at sufficient elevation angles, the accuracy is only 6% lower than TMF. By adopting the b and c coefficients of VMF3, TMF can keep its high accuracy with less computational cost, which could be meaningful for large-scale computing.

关键词： tropospheric delay ray-trace mapping function tilting troposphere gradient

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A New mapping function for Spaceborne TEC Conversion Based on the Plasmaspheric Scale Height

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REMOTE SENSING 2021年第23期13卷

作者： Wu, Mengjie Guo, Peng Zhou, Wei Xue, Junchen Han, Xingyuan Meng, Yansong Hu, Xiaogong Chinese Acad Sci Shanghai Astron Observ Shanghai 200030 Peoples R China Shanghai Key Lab Space Positioning & Nav Shanghai 200030 Peoples R China Taizhou Univ Adv Res Inst Taizhou 318000 Peoples R China Beijing Inst Tracking & Telecommun Technol BITTI Beijing 100094 Peoples R China China Acad Space Technol Xian Xian 710100 Peoples R China

The mapping function is crucial for the conversion of slant total electron content (TEC) to vertical TEC for low Earth orbit (LEO) satellite-based observations. Instead of collapsing the ionosphere into one single shell in commonly used mapping models, we defined a new mapping function assuming the vertical ionospheric distribution as an exponential profiler with one simple parameter: the plasmaspheric scale height in the zenith direction of LEO satellites. The scale height obtained by an empirical model introduces spatial and temporal variances into the mapping function. The performance of the new method is compared with the mapping function F&K by simulating experiments based on the global core plasma model (GCPM), and it is discussed along with the latitude, seasons, local time, as well as solar activity conditions and varying LEO orbit altitudes. The assessment indicates that the new mapping function has a comparable or better performance than the F&K mapping model, especially on the TEC conversion of low elevation angles.

关键词： radio occultation TEC mapping function plasmaspheric scale height GCPM

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Stress analysis for an arbitrary-shaped tunnel in orthotropic rock masses based on a simple mapping function

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TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 2023年 240卷

作者： Zhou, Yulin Zhang, Ning Ma, Yaocai Lu, Aizhong North China Elect Power Univ Inst Hydroelect & Geotech Engn Beijing 102206 Peoples R China North China Elect Power Univ Sch Water Resources & Hydropower Engn Beijing 102206 Peoples R China Tongji Univ Coll Civil Engn Dept Geotech Engn Shanghai 200092 Peoples R China 2 Beinong Rd Huilongguan Beijing 102206 Peoples R China

Most natural rock masses are anisotropic, but there is no simple and effective method to quickly and accurately calculate the stress at any point in the tunnel with an arbitrary shape in orthotropic rock masses. In this paper, first, the hole shapes of the z1- and z2-planes are calculated from the hole shapes of the z-plane, and then the outer regions of these two planes are mapped to the C1- and C2-planes, respectively, and an efficient algorithm to determine the mapping function is provided. After mapping, the stress boundary conditions originally expressed by z as the independent variable are transformed into C1 and C2 as the independent variables, posing new dif-ficulties to the solution of the stress boundary condition. To solve the stress boundary conditions, in this paper, the power series solution and the boundary collocation method are proposed, and two complex potential functions expressed by series are obtained. The stress and displacement of each point on and outside the hole can be easily calculated because the form of the two mapping functions is simple. Finally, the correctness of this method is evaluated by comparing the stress calculated using this method with the stress calculated using the previous methods and numerical simulation software.

关键词： Orthotropic Tunnel with arbitrary hole shape mapping function Boundary collocation method Stress and displacement

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Analytical solution of an orthotropic elasticity for a frictional rigid flat punch on a half plane with an oblique edge crack using a mapping function

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MECHANICS RESEARCH COMMUNICATIONS 2022年 125卷

作者： Hasebe, Norio Nagoya Inst Technol Dept Civil Engn & Syst Management Nagoya Aichi 4668555 Japan

A solution of an orthotropic elastic plane problem is derived for a frictional rigid flat punch on a half plane with an oblique edge crack. A mapping function is used for arbitrary configurations. No stress function using a mapping function seems to have been derived. The problem is solved as a Riemann???Hilbert problem. The final exact stress functions are represented by an irrational mapping function as a closed form. Stress components are represented by one complex variable. Arbitrarily shaped half plane problems can be solved by exchanging the mapping function. Therefore, once the analytical solution has been derived, calculating the stress components is simpler than for an isotropic problem. It is easier to use an irrational mapping function than to form a rational mapping function for an isotropic problem. As an example, the stress distributions are shown for a frictional coefficient and an oblique edge crack angle. Four elastic constants are expressed by two independent parameters.

关键词： Orthotropic plane Frictional flat rigid punch Coulomb ?s frictional law Riemann-Hilbert problem mapping function Mixed boundary value

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