Distortion Index Research Articles

Who Feel Cheated? Analyst Graphic Distortion and Punishment by Investors

The literature about sell-side analysts (analysts) is broad. Nonetheless, little research has been done regarding how these sophisticate users of financial information disclosed current and target price in form of graph. More precisely, we try to investigate if analysts are prone to distort the graph information and what would be the likelihood to continue to follow the ‘noisy analyst’ by non-professional investors. We also try to measure what would be the likelihood to continue to invest in the security. We apply Tuffle (1992) Graph Distortion Index (GDI) and notice that analysts are prone to distort graphs. We also applied laboratory experiment to measure the likelihood of non-professional investors to continue to follow the analyst and to continue to invest in the security. We find that investors ‘punish’ the noisy analyst by reducing the likelihood to follow him/her. The non-professional investors also reduce the likelihood to continue to invest in the firm, even if the data provided in terms of numbers are correct. These findings shed new light in the financial literature and by confirming that ‘normal people’ tend to trust by reflexiveness, and are prone to cognitive errors.

An NMR Crystallographic Investigation of the Relationships between the Crystal Structure and 29Si Isotropic Chemical Shift in Silica Zeolites.

NMR crystallography has recently been applied to great effect for silica zeolites. Here we investigate whether it is possible to extend the structural information available from routine NMR spectra via a simple structure–spectrum relationship. Unlike previous empirically derived relationships that have compared experimental crystal structures for (often disordered) silicates with experimental NMR spectra, where the structure may not be an accurate representation of the material studied experimentally, we use NMR parameters calculated by density functional theory (DFT) for both model Si(OSi(OH)3)4 clusters and also extended zeolitic SiO2 frameworks, for which the input structure corresponding to the NMR parameters is known exactly. We arrive at a structure–spectrum relationship dependent on the mean Si–O bond length, mean Si–O–Si bond angle, and the standard deviations of both parameters, which can predict to within 1.3 ppm the 29Si isotropic magnetic shielding that should be obtained from a DFT calculation. While this semiempirical relationship will never supersede DFT where this is possible, it does open up the possibility of a rapid estimation of the outcome of a DFT calculation where the actual calculation would be prohibitively costly or otherwise challenging. We also investigate the structural optimization of SiO2 zeolites using DFT, demonstrating that the mean Si–O bond lengths all tend to 1.62 Å and the distortion index tends to <2.0°, suggesting that these metrics may be suitable for rapid validation of whether a given crystal structure represents a realistic local geometry around Si, or merely a bulk average with contributions from several different local geometries.

Optimal resonance-free third-order high-pass filters based on minimization of the total cost of the filters using Crow Search Algorithm

The most common damped filters (DFs) are the second-order, third-order, C-type, and double-tuned filters. Other DFs such as the first-order and band-pass filters exist, but their high operating losses considerably diminish their usage. In this paper, firstly, for the third-order damped filter with equal and unequal capacitors, the relations among their circuit parameters are derived. Secondly, the optimal design problem of the two third-order high-pass filters is formulated by regarding these expressions to minimize the filter cost taking into account both the investment and operating expenses. The total and individual harmonic distortion indices, power factor and the harmonic voltage amplification ratios which measure the filter’s resonance damping capability, are considered as constraints. A recent metaheuristic optimization technique based on the intelligent behavior of crows, known as the Crow Search Algorithm (CSA), is employed for the solution of the formulated design problem. Further, a comparative analysis of the two designs of the third-order high-pass filters and a third-order C-type filter is presented. The results reveal that all the proposed filters guarantee no electrical resonance hazards while maintaining the allowable limits for the various performance indices of the system, load, and filter. Besides, the comparative analysis validates that the C-type filter provides higher power factor, system efficiency and transmission loss improvement than the other two filters, and that the proposed filters achieve almost the same voltage and current harmonic mitigation levels. The solution of the cost minimization problem reveals that the C-type filter and the third-order high-pass filter with equal capacitors have the worst and best resonance damping capabilities respectively, under the worst case conditions. Additionally, the filters with the lowest and highest cost are found as the third-order filter with unequal capacitors and the C-type one, respectively. Besides, the CSA is compared to the genetic algorithm (GA), and particle swarm optimization (PSO) techniques and the results show the fast convergence capability and the effectiveness of the proposed algorithm in solving the problem of optimal design of third-order resonance-free passive filters in distribution networks.

A posteriori decision analysis based on Resonance Index and NSGA-II applied to the capacitor banks placement problem

This paper proposes a new methodology based on the use of Resonance Index (RI) analysis as a posteriori decision-making procedure to check solutions of the optimization algorithm NSGA-II against resonance, when applied to the capacitor banks placement problem in radial distribution systems. Most of existing methodologies approach harmonic resonance in the referred problem through the inclusion of constraints in the optimization procedure with respect to the harmonic distortion indexes THD and IHD. However, monitoring only these two parameters is not sufficient to identify specific problems on capacitor banks due to harmonic resonance. To demonstrate this point, a RI analysis using the resonant chart was performed considering a 34-bus radial system. Also, the proposed a posteriori analysis is compared with the one that includes directly RI as a constraint in the optimization procedure, demonstrating that the proposed approach has a better performance with respect to computational time.

Analysis and Modelling of Power-Dependent Harmonic Characteristics of Modern PE Devices in LV Networks

This paper presents results of experimental and analytical evaluation of power-dependent harmonic emission of three common types of modern low-voltage (LV) power-electronic (PE) devices. After a detailed analysis of comprehensive test results, based on both existing and new waveform distortion indices, the development of component-based models of PE devices is discussed. This paper demonstrates the importance of including PE devices' controls for accurate modelling of their characteristics over the entire range of operating powers. Most of the analyzed PE devices exhibit strong power-dependent changes of characteristics, additionally influenced by supply-voltage conditions, which are important for the analysis of both existing networks and future “smart grids”.

S-shaped Inlet Flow Characteristics Test Rig Design and Experimental Research

An inlet flow characteristics test bench was designed for the high offset s-shaped inlet. Parametric design method was used in the design of direct-connect contraction. Numerical simulation results showed export velocity of the designed contraction distributed uniformly, the boundary layer was thin, which had good air contraction effect. Steady state flow characteristics test of the s-shaped inlet was carried out on the inlet test bench, and effectively verified the performance indicators of it. Test results showed that an obvious low pressure area existed on the bottom wall after the first corner of the s-shaped inlet. With the increase of inlet Mach number, the exit flow field quality deteriorated. When the inlet Mach number was 0.72, the export distortion index DC60 was over 17%, which could not meet the needs of normal work of the engine.

High-temperature behaviour of astrophyllite, K2NaFe7 2+Ti2(Si4O12)2O2(OH)4F: a combined X-ray diffraction and Mössbauer spectroscopic study

High-temperature X-ray powder-diffraction study of astrophyllite, K2NaFe7 2+Ti2(Si4O12)2O2(OH)4F, and investigation of the samples annealed at 600 and 700 °C, reveal the occurrence of a phase transformation due to the thermal iron oxidation coupled with (1) deprotonation according to the scheme Fe2+ + OH− → Fe3+ + O2− + ½H2 ↑, and (2) defluorination according to the scheme Fe2+ + F− → Fe3+ + O2−. The phase transformation occurs at 500 °C, it is irreversible and without symmetry changes. The mineral decomposes at 775 °C. Both astrophyllite and its high-temperature dehydroxylated (HT) modification are triclinic, P-1. The unit-cell parameters are a = 5.3752(1), b = 11.8956(3), c = 11.6554(3) A, α = 113.157(3), β = 94.531(2), γ = 103.112(2)o, V = 655.47(3) A3 for unheated astrophyllite, and a = 5.3287(4), b = 11.790(1), c = 11.4332(9) A, α = 112.530(8), β = 94.539(6), γ = 103.683(7)o, V = 633.01(9) A3 for the HT (annealed) modification of astrophyllite. The oxidation of iron is confirmed: (1) by the presence of an exothermic effect at 584 °C in the DTA/TG curves in an Ar–O atmosphere and its absence in an Ar–Ar atmosphere and (2) by ex situ Mossbauer spectroscopy that showed the oxidation of Fe2+ to Fe3+ in the samples heated to 700 °C. Deprotonation was detected by the evolution of IR spectra in the region 3600–3000 cm−1 for astrophyllite and its HT modification. Defluorination was detected by the presence of F in the electron microprobe analysis of unheated astrophyllite and the absence of F in the analysis of unpolished heated astrophyllite. The significant difference between astrophyllite and its HT modification is in the reduction of the M–O interatomic distances after heating to 500 °C and the distortion indices of the MO6 and Dφ6 octahedra. Thermal behaviour of astrophyllite in the 25–475 °C temperature range can be described as a volume thermal expansion with maximal coefficient of thermal expansion in the direction perpendicular to the plane of the HOH layers. In contrast, the HT phase experiences a strong contraction in the 600–775 °C temperature range, again in the direction perpendicular to the plane of the HOH layers.

Faking Bad in Workers Compensation Psychological Assessments: Elevation Rates of Negative Distortion Scales on the Personality Assessment Inventory in an Australian Sample

The workers compensation system provides a clear external incentive for deliberate feigning of physical or mental illness to some individuals. Although it has been asserted that all pre-liability workers compensation psychological assessments should involve assessment of deliberate feigning, the lack of an agreed standard for assessing this response style creates a substantial challenge in practice. Over the last two decades, substantial attention has been given to measures of psychopathology that also include validated negative distortion indices. The Personality Assessment Inventory) has been validated in both the clinical and forensic population, and is reportedly used by many Australian psychologists. This study explores rates of elevation of negative distortion scales on the PAI as a potential indicator of deliberate feigning in a large Australian workers compensation sample.

Image quality assessment based on multi-feature extraction and synthesis with support vector regression

Serving as quality monitor and evaluator, image quality assessment (IQA) plays an important role in various image processing systems. With humans on the receiving end of these systems, it is evident that desirable IQA methods should correlate well with subjective sensations. Yet traditional methods are usually either inaccurate for lack of consideration on human visual system (HVS) or too complex due to excessive effort on HVS simulation. To the pursuit of both accuracy and efficiency, we propose a method based on the exploitation of features closely related to image inherent quality. Specifically, in the novel method, Sobel operator, log Gabor filter and local pattern analysis are employed for complementary representation of image quality to make use of the properties of the primary and secondary visual cortex in HVS. Finally, support vector regression is implemented for the synthesis of the multiple distortion indices and mapping the quantification into an objective quality score. Experiments conducted on four large-scale databases, i.e. LIVE, TID2008, TID2013, and CSIQ prove that the objective evaluation of image quality by our method is highly consistent with subjective perception, and it is robust across different databases and distortion types.

Characteristics of Cordierite (Iolite) of Bandarguha-Orabahala Area, Kalahandi District, Odisha, India

Optical microscopy, X-ray diffractometry, micro CT studies and mineral chemistry by SEM-EDS has been carried out on cordierite rich rock fragments from Bandarguha and Orabahala areas of Kalahandi district, Odisha. Macroscopically, cordierite grains exhibit distinct pleochroism in the shades of violet blue to light blue and colourless and are of gem quality (iolite). Biotite is the dominant associated mineral and Mg-Fe distribution coefficient (KD) between coexisting cordierite and biotite varies from 1.71 to 2.76. The cordierite is low cordierite (distortion index, Δ=0.257). Mineral analyses indicate that cordierite is magnesian rich (XMg=0.82-0.88) with limited Fe2+ substitution for Mg2+ and dichroism is due to presence of part of iron in ferric form. Cordierite is formed during metamorphism by reactions: (a) orthopyrox ene+sillimanite+quartz=cordierite+K-feldspar+water and (b) orthopyroxene+sillimanite=cordierite+corundum.

Indexing Structural Distortion: Sectoral Productivity, Structural Change and Growth

This paper proposes a new index of sectoral labor distortion using employment and valueadded shares. We show that this index is highly correlated with growth both crosssectionally and over time. We also use it to compare the degree of distortion among countries and identify sectors where the potential payoffs in terms of growth from reforms could be large. The regression analysis in the paper shows that education and various structural reforms have potential to improve the efficiency of sectoral labor allocation.

Indexing Structural Distortion: Sectoral Productivity, Structural Change and Growth

This paper proposes a new index of sectoral labor distortion using employment and valueaddedshares. We show that this index is highly correlated with growth both crosssectionallyand over time. We also use it to compare the degree of distortion amongcountries and identify sectors where the potential payoffs in terms of growth from reformscould be large. The regression analysis in the paper shows that education and variousstructural reforms have potential to improve the efficiency of sectoral labor allocation.

Temperature dependent structural, vibrational and magnetic properties of K3Gd5(PO4)6.

Herein we report the evolution of the crystal structure of K3Gd5(PO4)6 in the temperature range from 20 K to 1073 K, as observed from variable temperature X-ray diffraction and Raman spectroscopic studies. K3Gd5(PO4)6 has an open tunnel containing a three dimensional structure built by [Gd5(PO4)6]3- ions which in turn are formed of PO4 tetrahedra and GdOn (n = 8 and 9) polyhedra. The empty tunnels in the structure are occupied by K+ ions and maintain charge neutrality in the lattice. Evolution of unit cell parameters with temperature shows a systematic increase with temperature. The average axial thermal expansion coefficients between 20 K and 1073 K are: αa = 10.6 × 10-6 K-1, αb = 5.5 × 10-6 K-1 and αc = 16.4 × 10-6 K-1. The evolution of distortion indices of the various coordination polyhedra with temperature indicates a gradual decrease with increasing temperature, while those of Gd2O9 and K2O8 polyhedra show opposite trends. The overall anisotropy of the lattice thermal expansion is found to be controlled largely by the effect of temperature on GdOn polyhedra and their linkages. Temperature dependent Raman spectroscopic studies indicated that the intensities and wavenumbers of most of the Raman modes decrease continuously with increasing temperature. Anharmonic analyses of Raman modes indicated that the lattice, rigid translation and librational modes have larger contributions towards thermal expansion of K3Gd5(PO4)6 compared to high frequency internal modes. The temperature and field dependent magnetic measurements indicated no long range ordering down to 2 K and the observed effective magnetic moment per Gd3+ ion and the Weiss constant are 7.91 μB and 0.38 K, respectively.

Capacitor and passive filter placement in distribution systems by nondominated sorting genetic algorithm-II

The optimization of passive filters in distribution systems has been addressed through different approaches. In general, these approaches can be classified as single-objective and multi-objective formulations. The single-objective formulations normally try to determine the least costly filters that ensure compliance with the relevant power quality standards. In multi-objective approaches, other goals are added. In general, most studies consider the reactive power of filters at a fundamental frequency to be equal to a previously determined magnitude, and the optimization is devoted to calculate the other parameters of the filters that are required to minimize the distortion indices of the network. In the present approach, the capacitor placement and passive filter placement problems are considered as a unified problem in which a set of passive compensators (capacitors and/or tuned filters) that allow to obtain the maximum annual saving in cost and maximum improvement of the power quality of the circuit are determined. In this study, the annual saving is calculated as the equivalent present value of the compensation project to simultaneously account for the benefits of the reactive power compensation and the cost of investment in the compensators. Although many studies have solved the multi-objective problem by minimizing a single function comprising several subobjectives, this study employs the nondominated sorting genetic algorithm for the optimization of several objective functions. The present approach is tested with two example circuits from literature.

Behavior of the Linea Alba During a Curl-up Task in Diastasis Rectus Abdominis: An Observational Study.

Study Design Cross-sectional repeated measures. Background Rehabilitation of diastasis rectus abdominis (DRA) generally aims to reduce the inter-rectus distance (IRD). We tested the hypothesis that activation of the transversus abdominis (TrA) before a curl-up would reduce IRD narrowing, with less linea alba (LA) distortion/deformation, which may allow better force transfer between sides of the abdominal wall. Objectives This study investigated behavior of the LA and IRD during curl-ups performed naturally and with preactivation of the TrA. Methods Curl-ups were performed by 26 women with DRA and 17 healthy control participants using a natural strategy (automatic curl-up) and with TrA preactivation (TrA curl-up). Ultrasound images were recorded at 2 points above the umbilicus (U point and UX point). Ultrasound measures of IRD and a novel measure of LA distortion (distortion index: average deviation of the LA from the shortest path between the recti) were compared between 3 tasks (rest, automatic curl-up, TrA curl-up), between groups, and between measurement points (analysis of variance). Results Automatic curl-up by women with DRA narrowed the IRD from resting values (mean U-point between-task difference, -1.19 cm; 95% confidence interval [CI]: -1.45, -0.93; P<.001 and mean UX-point between-task difference, -0.51 cm; 95% CI: -0.69, -0.34; P<.001), but LA distortion increased (mean U-point between-task difference, 0.018; 95% CI: 0.0003, 0.041; P = .046 and mean UX-point between-task difference, 0.025; 95% CI: 0.004, 0.045; P = .02). Although TrA curl-up induced no narrowing or less IRD narrowing than automatic curl-up (mean U-point difference between TrA curl-up versus rest, -0.56 cm; 95% CI: -0.82, -0.31; P<.001 and mean UX-point between-task difference, 0.02 cm; 95% CI: -0.22, 0.19; P = .86), LA distortion was less (mean U-point between-task difference, -0.025; 95% CI: -0.037, -0.012; P<.001 and mean UX-point between-task difference, -0.021; 95% CI: -0.038, -0.005; P = .01). Inter-rectus distance and the distortion index did not change from rest or differ between tasks for controls (P≥.55). Conclusion Narrowing of the IRD during automatic curl-up in DRA distorts the LA. The distortion index requires further validation, but findings imply that less IRD narrowing with TrA preactivation might improve force transfer between sides of the abdomen. The clinical implication is that reduced IRD narrowing by TrA contraction, which has been discouraged, may positively impact abdominal mechanics. J Orthop Sports Phys Ther 2016;46(7):580-589. doi:10.2519/jospt.2016.6536.

SU‐G‐206‐04: A Method for Realizing Phantom Calibration and Geometry Calibration Accurately Based On a Geometry Evaluation Index

Purpose:For traditional geometric calibration, the calibration accuracy relies on both accuracy of geometry phantom manufacture and accuracy of ball bearings (BB) location estimation. In this work, we have developed a method to perform phantom calibration and geometry calibration iteratively and accurately in a whole procedure.Methods:We have designed and manufactured a geometry phantom with BB and an evaluation phantom of a crystal ball contained in a cubic gel box. Our calibration method consists of five steps: 1) Estimate BB locations using spiral CT image, which are then used to initialize the particles in Particle Swarm Optimization (PSO) algorithm; 2) Perform geometric calibration; 3) Reconstruct the images of the evaluation phantom based on the current geometry calibration; 4) Evaluate the reconstructed images using a geometry evaluate index; 5) Update BB locations in PSO algorithm. Repeat step2)‐5) until our stopping criteria is met. The edge of the crystal ball in the calibration phantom on CBCT images is detected by Hough transform to define two circular rings outside and inside the ball. The evaluation index used in step 4) is defined as the difference of the averaged image intensities of these two circular rings.Results:We have demonstrated the feasibility and performance of our method on a benchtop CBCT system. It is observed that inaccurate BB locations lead to severe image distortion and relative small evaluation index. With our method, streak artifacts are reduced and the structure becomes sharper and clearer. The evaluation index increases fast within 10 iterations, and then becomes stable gradually.Conclusion:Our method can perform accurate phantom calibration and geometry calibration together in a whole procedure. It helps to mitigate the impact of the geometry phantom manufacture errors on the calibration, which could hence save the cost of the geometry phantom manufacture.

Automating the selection of standard parallels for conic map projections

Conic map projections are appropriate for mapping regions at medium and large scales with east–west extents at intermediate latitudes. Conic projections are appropriate for these cases because they show the mapped area with less distortion than other projections. In order to minimize the distortion of the mapped area, the two standard parallels of conic projections need to be selected carefully. Rules of thumb exist for placing the standard parallels based on the width-to-height ratio of the map. These rules of thumb are simple to apply, but do not result in maps with minimum distortion. There also exist more sophisticated methods that determine standard parallels such that distortion in the mapped area is minimized. These methods are computationally expensive and cannot be used for real-time web mapping and GIS applications where the projection is adjusted automatically to the displayed area. This article presents a polynomial model that quickly provides the standard parallels for the three most common conic map projections: the Albers equal-area, the Lambert conformal, and the equidistant conic projection. The model defines the standard parallels with polynomial expressions based on the spatial extent of the mapped area. The spatial extent is defined by the length of the mapped central meridian segment, the central latitude of the displayed area, and the width-to-height ratio of the map. The polynomial model was derived from 3825 maps—each with a different spatial extent and computationally determined standard parallels that minimize the mean scale distortion index. The resulting model is computationally simple and can be used for the automatic selection of the standard parallels of conic map projections in GIS software and web mapping applications.

Structure of hydroxyapatite powders prepared through dicalcium phosphate dihydrate hydrolysis

We have studied the structure of hydroxyapatite (HA) powders prepared by hydrolyzing dicalcium phosphate dihydrate (DCPD) in an aqueous sodium acetate solution at a temperature of 60°C for 16 h or a longer time. The results demonstrate that the HA in the powders has a distorted structure. The Baur’s distortion index for the PO4 tetrahedra is DI(TO) ≃ 0.03, whereas hydroxyapatite single crystals have DI(TO) ≃ 0.005. The powders are similar in structural parameters to calcium-deficient HAs: they have Ca/P ≃ 1.6 and an imperfect substructure (crystallite size of ≃30 nm) and contain sodium impurities. The structural features of the HA powders are analyzed in the context of their ability to biodegrade (dissolve).

The structural evolution and spectral blue shift of solid solution phosphors Sr3−mCamB2O6:Eu2+

An unexpected spectral blue shift of the emission from yellow to green is observed for the solid solution phosphors Sr3−mCamB2O6:Eu2+ (m = 0–3), when larger Sr2+ ions are substituted by smaller Ca2+ ions in Sr3B2O6 lattices. The powder X-ray patterns of all the phases indicate a structural similarity to the end compounds and show a smooth variation of the structural parameters with composition in the full range. The linear structural evolution of the iso-structural Sr3−mCamB2O6 solid solutions obeying Vegard's rule has also been examined and verified by Rietveld refinement, high resolution transmission electron microscopy and Fourier transform infrared spectroscopy. The average bond lengths of the central cations to the coordinating anions and the distortion indexes of the coordination polyhedra are investigated. As a result, the symmetry of the coordination crystal field is found to be higher with increasing Ca content in the solid solutions phosphors, which should be primarily responsible for the continuous blue shift of the emission spectra of Sr2.96−mCamB2O6:0.04Eu2+ with the growth of the m value.

Automatic Segmentation of Bones in X-ray Images Based on Entropy Measure

In this paper, we introduce an efficient method for segmenting the bone region of an X-ray image from its surrounding muscles and tissues. Automated segmentation of the bone part in a digital X-ray image is a challenging problem because of its low contrast with the surrounding flesh. The presence of noise and spurious edges further complicates the segmentation. Most of the existing methods either suffer from noisy contour detection or need training samples for manual tuning of certain thresholding parameters. We propose a fully automated segmentation technique, which utilizes a variant of entropy measure of the image. This scheme has been shown to be useful for fast and efficient analysis of a wide class of human X-ray images including skull, chest, pelvic region and ortho-dental zones. In order to quantify the quality of segmentation, we propose a new metric called average contour distortion index (ACDI) based on certain neighborhood properties of the contour pixels. Experiments on several X-ray images reveal encouraging results compared to other approaches as evident from the ACDI metric. We also re-validate the quality of several segmented bone images using segmentation entropy quantitative assessment (SEQA), and boundary-based precision–recall profile. All three metrics establish the superiority of the proposed technique to prior art.