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Journal articles on the topic 'Pattern-Based Corrections'
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1
Schulze, Hans-Henning, Andreas Cordes, and Dirk Vorberg. "Keeping Synchrony While Tempo Changes: Accelerando and Ritardando." Music Perception 22, no. 3 (2005): 461–77. http://dx.doi.org/10.1525/mp.2005.22.3.461.
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We studied synchronization with a metronome that smoothly changes tempo, from slow to fast (accelerando) or from fast to slow (ritardando). During the transition phase, systematic alternations of underadjustment and overadjustment of period and phase were observed. We analyzed the synchronization error (�asynchrony�) sequences in terms of two models that both assume linear period and phase correction mechanisms but differ in terms of how the timekeeper period is adjusted to the tempo change. In the interval-based model, period corrections are based on comparisons between timekeeper and metronome intervals, whereas in the asynchrony-based model, period corrections are based on the deviations of taps from metronome events. The qualitative data pattern is more compatible with an asynchrony-based model than with an interval-based model. Additional mechanisms that switch on and off period adjustment seem to be needed, however, for a quantitative fit of this model to our data.
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Tippett, Michael K., Anthony G. Barnston, David G. DeWitt, and Rong-Hua Zhang. "Statistical Correction of Tropical Pacific Sea Surface Temperature Forecasts." Journal of Climate 18, no. 23 (December 1, 2005): 5141–62. http://dx.doi.org/10.1175/jcli3581.1.
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Abstract This paper is about the statistical correction of systematic errors in dynamical sea surface temperature (SST) prediction systems using linear regression approaches. The typically short histories of model forecasts create difficulties in developing regression-based corrections. The roles of sample size, predictive skill, and systematic error are examined in evaluating the benefit of a linear correction. It is found that with the typical 20 yr of available model SST forecast data, corrections are worth performing when there are substantial deviations in forecast amplitude from that determined by correlation with observations. The closer the amplitude of the uncorrected forecasts is to the optimum squared error-minimizing amplitude, the less likely is a correction to improve skill. In addition to there being less “room for improvement,” this rule is related to the expected degradation in out-of-sample skill caused by sampling error in the estimate of the regression coefficient underlying the correction. Application of multivariate [canonical correlation analysis (CCA)] correction to three dynamical SST prediction models having 20 yr of data demonstrates improvement in the cross-validated skills of tropical Pacific SST forecasts through reduction of systematic errors in pattern structure. Additional beneficial correction of errors orthogonal to the CCA modes is achieved on a per-gridpoint basis for features having smaller spatial scale. Until such time that dynamical models become freer of systematic errors, statistical corrections such as those shown here can make dynamical SST predictions more skillful, retaining their nonlinear physics while also calibrating their outputs to more closely match observations.
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Oinonen, M., P. Pesonen, and M. Tallavaara. "Archaeological Radiocarbon Dates for Studying the Population History in Eastern Fennoscandia." Radiocarbon 52, no. 2 (2010): 393–407. http://dx.doi.org/10.1017/s0033822200045446.
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In this work, archaeological radiocarbon data gathered from eastern Fennoscandia have been scrutinized to discuss their suitability for studies of population history. The temporal distribution of the archaeological 14C dates has been analyzed against possible research priorities and sample material deterioration. An outstanding “Stone Age” maximum has been observed in practically all the displayed temporal date distributions. The pattern remains the same throughout the history of 14C dating in Finland. Due to sample material differences, equal taphonomic corrections based on 14C-dated volcanic deposits cannot account for all the sample degradation effects; therefore, material-dependent correction procedures are suggested.
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Jalilov, Ya R., V. Q. Verdiyev, and T. Y. Jalilov. "Application of Cross-Section Corrective («Translation») Forces at Surgical Treatment for Scoliosis." N.N. Priorov Journal of Traumatology and Orthopedics 19, no. 3 (September 15, 2012): 14–19. http://dx.doi.org/10.17816/vto20120314-19.
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Surgical treatment results for 53 patients with III—IV stage of scoliosis are presented. In all patients original endocorrector has been applied. Endocorrector is based on the application of cross-section corrective («translation effect») forces that enable to shift the vertebrae of the main scoliotic arch to the median line of the trunk. Endocorrector was the most effective in curvature arch under 75° and provided 35—45° correction. Mathematic modeling of a situation «endocor- rector—curved spine» was performed as well as the pattern of forces created by endocorrector and participated in the scoliotic deformity correction was studied. Surgical intervention enabled to achieve stable fixation of the spine with its sagittal contours preservation. At long-term follow up (1—6 years) loss of correction did not exceed 8—10°. In scoliosis with arch over 75° step-by- step corrections were performed and loss of correction could make up 15°.
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Akmal, Fachrurrozy. "PENOLOGI PENGAYOMAN." Khatulistiwa Law Review 1, no. 1 (April 15, 2020): 39–60. http://dx.doi.org/10.24260/klr.v1i1.36.
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This study aims to analyze the punishment pattern in the national penal system. This is a consequence of the involvement of science in the penal concept in Indonesia with a focus of research to understand the role of science in addressing the challenges related to policymaking, fostering treatment, as well as prisoner guidance which is carried out by the technical implementation unit (UPT) within the Directorate General of Corrections. Based on the analysis, the method used in this paper is juridical normative with positive legal approaches and descriptive-analytical research. The discussion in this paper states that punishment pattern in Indonesia refers to the principle of protection that functions in providing a sense of security for all parties both perpetrators of crime, victims and especially the community. The principle of punishment in the protection always seeks to see the success of a pattern of treatment within the framework of behavioral change of a person's criminality before the reintegration into society. Leadership and power of correctional institutions in the concept of aegis penology are oriented to the creation of productive and democratic spaces. The success of leadership in a punishment process is also determined by the transparency of the discourses. The presence of science in treatment and guidance aims to prevent fallacy such as a tendency in the generalization of different prisoner characters in the correctional process. Besides, the presence of knowledge in the guidance determines the pattern and appropriate treatment to correctional clients.
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Sulchan, Achmad, Akhmad Khisni, and Aryani Witasari. "FAIR INMATE COACHING PATTERNS (A STUDY IN CORRECTIONAL INSTITUTION OF KEDUNGPANE SEMARANG)." Jurnal Pembaharuan Hukum 7, no. 1 (April 3, 2020): 57. http://dx.doi.org/10.26532/jph.v7i1.11124.
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Correctional Institutions have a very strategic task as the most potential place in realizing the objectives of punishment with coaching. However, this cannot be realized without the awareness of the inmates themselves. To realize this, the Correctional Institution functions as an educational institution that provides useful training for inmates to create, produce, and excel. They have the same opportunity as other community members to be able to contribute as active and productive community members in development. Inmate coaching must also be beneficial for the person concerned during his/her imprisonment at the Correctional Institution of Kedungpane, Semarang, and after completing the imprisonment, returning to the community. Thus, the fair coaching pattern of inmates is implemented with the correctional system and, basically, a situation/condition that allows for the realization of correctional objectives in accordance with the definition of coaching i.e. the process carried out by the Correctional Institution to inmates. For better and fairer coaching without any discrimination, the Corrections Institution should carry out its main duties as stipulated in the "Ten Correctional Principles". This study is based on the legal positivism concept, which states that norms are written, made and promulgated by state authorities, and uses a qualitative method to produce a description of the fair coaching pattern at the Correctional Institution of Kedungpane, Semarang.
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Druyan, Leonard, and Matthew Fulakeza. "Downscaling Atmosphere-Ocean Global Climate Model Precipitation Simulations over Africa Using Bias-Corrected Lateral and Lower Boundary Conditions." Atmosphere 9, no. 12 (December 12, 2018): 493. http://dx.doi.org/10.3390/atmos9120493.
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A prequel study showed that dynamic downscaling using a regional climate model (RCM) over Africa improved the Goddard Institute for Space Studies Atmosphere-Ocean Global Climate Model (GISS AOGCM: ModelE) simulation of June–September rainfall patterns over Africa. The current study applies bias corrections to the lateral and lower boundary data from the AOGCM driving the RCM, based on the comparison of a 30-year simulation to the actual climate. The analysis examines the horizontal pattern of June–September total accumulated precipitation, the time versus latitude evolution of zonal mean West Africa (WA) precipitation (showing monsoon onset timing), and the latitude versus altitude cross-section of zonal winds over WA (showing the African Easterly Jet and the Tropical Easterly Jet). The study shows that correcting for excessively warm AOGCM Atlantic sea-surface temperatures (SSTs) improves the simulation of key features, whereas applying 30-year mean bias corrections to atmospheric variables driving the RCM at the lateral boundaries does not improve the RCM simulations. We suggest that AOGCM climate projections for Africa should benefit from downscaling by nesting an RCM that has demonstrated skill in simulating African climate, driven with bias-corrected SST.
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Paulik, Róbert, Miklós Kozlovszky, and Béla Molnár. "Regression Based Iterative Illumination Compensation Method for Multi-Focal Whole Slide Imaging System." Sensors 21, no. 21 (October 26, 2021): 7085. http://dx.doi.org/10.3390/s21217085.
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Image quality, resolution and scanning time are critical in digital pathology. In order to create a high-resolution digital image, the scanner systems execute stitching algorithms to the digitized images. Due to the heterogeneity of the tissue sample, complex optical path, non-acceptable sample quality or rapid stage movement, the intensities on pictures can be uneven. The evincible and visible intensity distortions can have negative effect on diagnosis and quantitative analysis. Utilizing the common areas of the neighboring field-of-views, we can estimate compensations to eliminate the inhomogeneities. We implemented and validated five different approaches for compensating output images created with an area scanner system. The proposed methods are based on traditional methods such as adaptive histogram matching, regression-based corrections and state-of-the art methods like the background and shading correction (BaSiC) method. The proposed compensation methods are suitable for both brightfield and fluorescent images, and robust enough against dust, bubbles, and optical aberrations. The proposed methods are able to correct not only the fixed-pattern artefacts but the stochastic uneven illumination along the neighboring or above field-of-views utilizing iterative approaches and multi-focal compensations.
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Jiang, Wenbin, Jie Zhang, and Lee Bell. "3D seismic geometry quality control and corrections by applying machine learning." GEOPHYSICS 84, no. 6 (November 1, 2019): P87—P96. http://dx.doi.org/10.1190/geo2018-0617.1.
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Seismic geometry quality control (QC) and corrections are crucial but labor-intensive steps in seismic data preprocessing. Current methods to estimate the correct positions of sources and receivers are usually based on the first-break traveltimes, which may contain large errors, thereby affecting the accuracy of the results. We have applied a deep convolutional neural network to identify shots and receivers that have position error, and we searched for the correct position. Once an error in position is identified by scanning data, a grid search for the correct location is conducted and the result is evaluated by the system until an optimal position is found. The network is trained on 3200 training sets from real data that have been corrected by the traditional method. Through cross validation on 800 sets, the classifier achieves a precision of 99.5% and a recall rate of 1. The final errors between the true positions and corrected positions are less than 10% of the shot spacing. An uncorrected real data experiment reveals that the proposed machine-learning method for geometry QC and correction provides similar results to the conventional manual correction approach but without human interference. Because the wavefield pattern of the training data for this purpose is global, there is no need to train the system again when applying the method to correct receiver position or process another data set. This claim is verified with different real data.
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Puaschunder, Julia. "Value at looking back:Towards an empirical validation of the role of reflexivity in econo-historic backtesting:Economic market prediction corrections correlate with future market performance." ACRN Journal of Finance and Risk Perspectives 8, no. 1 (2019): 223–39. http://dx.doi.org/10.35944/jofrp.2019.8.1.014.
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The following article innovatively paints a novel picture of the mass psychological underpinnings of business cycles based on information flows in order to recommend how certain communication strategies could counterweight and alleviate information failing market performance expectations that could potentially build disastrous financial market mass movements of booms and busts. An introduction to the history of economic cycles will lead to George Soros’ Theory of Reflexivity in order to draw inferences for the analysis of the role of information in creating economic booms and busts in the age of globalization. Empirically, based on a central European central bank’s GNP projections and backtesting corrections, a pattern of central bank corrections communication and economic market performance will be unraveled for the first time to outline that central bank market prediction corrections are positively correlated with near future market performances and negatively correlated with distant future market performances. The collective reality of prices and the irrationality of the crowds perturbating markets will be discussed. Business cycles are argued to obey some kind of natural complexity, as for being influenced by econo-historic communication trends. Recommendations how to create more stable economic systems by avoiding emergent risks in communicating market prospects more cautiously will be given in the discussion followed by a prospective future research outlook and conclusion.
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Akwaji, Fidelis Ngaji, Emeka Josephat Owan, Ahakiri Francis Idiege, Ibrahim Muhammad Hassan, Opara Ikechukwu Jonathan, Abonor, Lazarus Bassey, Abang Paul Eno, et al. "Social Support and the Rehabilitation of Convicts in Calabar Correctional Service Centre, Cross River State, Nigeria." Journal of Ecohumanism 3, no. 4 (July 18, 2024): 1030–41. http://dx.doi.org/10.62754/joe.v3i4.3528.
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This study examined the nexus between social support and rehabilitation of convicts. Social support for convicts has not received adequate research interest in Nigeria within the field of corrections. This is because correctional administrators have not acknowledged the importance of social support to the adjustment pattern and rehabilitation of convicts. Literature on social support is western based. This study will contribute in narrowing the methodological gap created by dearth of literature on social support. Survey design was used for the study. The study used 318 respondents as its sample. Data collection was carried out using structured questionnaire. Statistical analysis involved the use of the Pearson Product Moment Correlation Coefficient (PPMCC) and simple percentage. The study's results indicated a significant relationship between family, administrative and convicts supports and rehabilitation. Thus, it was recommended amongst others that; the family which is the basic unit of the society should always support one another.
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Stisen, Simon, Mohsen Soltani, Gorka Mendiguren, Henrik Langkilde, Monica Garcia, and Julian Koch. "Spatial Patterns in Actual Evapotranspiration Climatologies for Europe." Remote Sensing 13, no. 12 (June 19, 2021): 2410. http://dx.doi.org/10.3390/rs13122410.
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Spatial patterns in long-term average evapotranspiration (ET) represent a unique source of information for evaluating the spatial pattern performance of distributed hydrological models on a river basin to continental scale. This kind of model evaluation is getting increased attention, acknowledging the shortcomings of traditional aggregated or timeseries-based evaluations. A variety of satellite remote sensing (RS)-based ET estimates exist, covering a range of methods and resolutions. There is, therefore, a need to evaluate these estimates, not only in terms of temporal performance and similarity, but also in terms of long-term spatial patterns. The current study evaluates four RS-ET estimates at moderate resolution with respect to spatial patterns in comparison to two alternative continental-scale gridded ET estimates (water-balance ET and Budyko). To increase comparability, an empirical correction factor between clear sky and all-weather ET, based on eddy covariance data, is derived, which could be suitable for simple corrections of clear sky estimates. Three RS-ET estimates (MODIS16, TSEB and PT-JPL) and the Budyko method generally display similar spatial patterns both across the European domain (mean SPAEF = 0.41, range 0.25–0.61) and within river basins (mean SPAEF range 0.19–0.38), although the pattern similarity within river basins varies significantly across basins. In contrast, the WB-ET and PML_V2 produced very different spatial patterns. The similarity between different methods ranging over different combinations of water, energy, vegetation and land surface temperature constraints suggests that robust spatial patterns of ET can be achieved by combining several methods.
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Misrika, Dahlia, Erfiani Erfiani, and Aji Wigena. "Loopy Orthogonal Signal Correction Scatter Correction in Non-Invasive Blood Glucose." Indonesian Journal of Statistics and Its Applications 7, no. 2 (December 31, 2023): 105–13. http://dx.doi.org/10.29244/ijsa.v7i2p105-113.
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Spectroscopy is the study of matter based on light, sound, or particles emitted, absorbed, or reflected as well as the study of methods for generating and analyzing spectra. The spectrum has systematic diversity, namely the presence of light scattering and differences in the size of objects. The spectroscopic output allows for scattering shifts, because the same object measured several times does not exactly produce the same spectrum. Problems found in the spectrum can be overcome by pre-processing the data, namely the scatter correction method. Scatter correction is used to reduce the physical properties in the spectrum so that the information obtained is relatively the same for each spectrum, produces good estimates, and can be interpreted well. One of the spectroscopic tools that utilize infrared light is a non-invasive blood glucose level measuring device. The output of the tool is the time domain and intensity spectrum. Each object from the resulting spectrum still has noise, so scatter correction can be applied to this data. The purpose of this study was to perform a loopy Orthogonal Signal Correction (OSC) scatter correction method on time domain spectrum data on intensity on a non-invasive blood glucose level measuring device. The OSC method uses the concept of orthogonality to the mean by drawing the intensity value, weighting it, calculating the vector loading and then making corrections to the initial intensity. Based on the analysis, the loopy OSC method is better than OSC because the convergence is more accurate, the mean difference is smaller, the variance is smaller and the value converges on all the values tested. Based on exploration and the average difference, the loopy OSC method is better able to form the same pattern for each replication. This also shows that an object that is measured repeatedly has been able to be identified as the same object.
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Pujol, José, Jer-Ming Chiu, Arch Johnston, and Byau-Heng Chin. "On the relocation of earthquake clusters. A case history: The Arkansas earthquake swarm." Bulletin of the Seismological Society of America 79, no. 6 (December 1, 1989): 1846–62. http://dx.doi.org/10.1785/bssa0790061846.
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Abstract A portable digital network (the PANDA array) of 40 three-component stations with an aperture of about 35 km was deployed for 4 months in the Arkansas swarm area in 1987. Only 12 swarm events occurred during the deployment, in contrast to the intense seismic activity that characterized this region in 1982 to 1984. These events were relocated using a joint hypocentral determination technique (JHD). The JHD method used here allows for the simultaneous determination of P- and S-wave station corrections while providing information on the uniqueness of the solution based on the singular values of a matrix related to the station corrections. P-wave station corrections, determined when all nonzero singular values were used in the computations (or with the two smallest nonzero singular values deleted), show a circular pattern of positive values surrounded by negative values. The epicentral area is localized slightly displaced from the center of the pattern. Since positive and negative corrections correspond to velocities that are lower and higher, respectively, than the average, our results indicate that the swarm area is characterized by seismic velocities lower than those of its surroundings. Independent information on this region is afforded by reflection seismic lines recorded in the swarm area and its vicinity, which show that the hypocenters are located in a region where strong reflectors completely lose their coherence, indicating that this volume is anomalous when compared to surrounding crust. Additional support for a low-velocity zone comes from the results of a 3-D velocity inversion of the same PANDA data. A selected subset of data recorded digitally by the USGS in 1982 was also relocated. Comparison with the results from the PANDA data shows that the seismic activity did not migrate over a 5-yr period and that it is concentrated within a small volume between about 3 km and 6 km depth. While the results of this study do not determine the ultimate cause of the Arkansas swarm, the discovery of a pronounced localized low velocity zone is consistent with a previously proposed magmatic intrusion or a zone of highly fractured, fluid-filled crust.
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Yuan, Wenan, and Weiyun Hua. "A Case Study of Vignetting Nonuniformity in UAV-Based Uncooled Thermal Cameras." Drones 6, no. 12 (December 3, 2022): 394. http://dx.doi.org/10.3390/drones6120394.
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Uncooled thermal cameras have been employed as common UAV payloads for aerial temperature surveillance in recent years. Due to the lack of internal cooling systems, such cameras often suffer from thermal-drift-induced nonuniformity or vignetting despite having built-in mechanisms to minimize the noise. The current study examined a UAV-based uncooled thermal camera vignetting regarding camera warmup time, ambient temperature, and wind speed and direction, and proposed a simple calibration-based vignetting migration method. The experiments suggested that the camera needed to undergo a warmup period to achieve stabilized performance. The required warmup duration ranged from 20 to 40 min depending on ambient temperature. Camera vignetting severity increased with camera warmup time, decreasing ambient temperature, and wind presence, while wind speed and direction did not make a difference to camera vignetting during the experiments. Utilizing a single image of a customized calibration target, we were able to mitigate vignetting of outdoor images captured in a 30 min duration by approximately 70% to 80% in terms of the intra-image pixel standard deviation (IISD) and 75% in terms of the pixel-wise mean (PWMN) range. The results indicated that outdoor environmental conditions such as air temperature and wind speed during short UAV flights might only minimally influence the thermal camera vignetting severity and pattern. Nonetheless, frequent external shutter-based corrections and considering the camera nonlinear temperature response in future studies have the potential to further improve vignetting correction efficacy for large scene temperature ranges.
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Münchmeyer, Jannes, Dino Bindi, Christian Sippl, Ulf Leser, and Frederik Tilmann. "Low uncertainty multifeature magnitude estimation with 3-D corrections and boosting tree regression: application to North Chile." Geophysical Journal International 220, no. 1 (September 17, 2019): 142–59. http://dx.doi.org/10.1093/gji/ggz416.
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SUMMARY Magnitude estimation is a central task in seismology needed for a wide spectrum of applications ranging from seismicity analysis to rapid assessment of earthquakes. However, magnitude estimates at individual stations show significant variability, mostly due to propagation effects, radiation pattern and ambient noise. To obtain reliable and precise magnitude estimates, measurements from multiple stations are therefore usually averaged. This strategy requires good data availability, which is not always given, for example for near real time applications or for small events. We developed a method to achieve precise magnitude estimations even in the presence of only few stations. We achieve this by reducing the variability between single station estimates through a combination of optimization and machine learning techniques on a large catalogue. We evaluate our method on the large scale IPOC catalogue with >100 000 events, covering seismicity in the northern Chile subduction zone between 2007 and 2014. Our aim is to create a method that provides low uncertainty magnitude estimates based on physically meaningful features. Therefore we combine physics based correction functions with boosting tree regression. In a first step, we extract 110 features from each waveform, including displacement, velocity, acceleration and cumulative energy features. We correct those features for source, station and path effects by imposing a linear relation between magnitude and the logarithm of the features. For the correction terms, we define a non-parametric correction function dependent on epicentral distance and event depth and a station specific, adaptive 3-D source and path correction function. In a final step, we use boosting tree regression to further reduce interstation variance by combining multiple features. Compared to a standard, non-parametric, 1-D correction function, our method reduces the standard deviation of single station estimates by up to $57\, {\rm per\, cent}$, of which $17\, {\rm per\, cent}$ can be attributed to the improved correction functions, while boosting tree regression gives a further reduction of $40\, {\rm per\, cent}$. We analyse the resulting magnitude estimates regarding their residuals and relation to each other. The definition of a physics-based correction function enables us to inspect the path corrections and compare them to structural features. By analysing feature importance, we show that envelope and P wave derived features are key parameters for reducing uncertainties. Nonetheless the variety of features is essential for the effectiveness of the boosting tree regression. To further elucidate the information extractable from a single station trace, we train another boosting tree on the uncorrected features. This regression yields magnitude estimates with uncertainties similar to the single features after correction, but without using the earthquake location as required for applying the correction terms. Finally, we use our results to provide high precision magnitudes and their uncertainties for the IPOC catalogue.
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Abimanyu, Amarif, Widodo S. Pranowo, Ibnu Faizal, Najma K. A. Afandi, and Noir P. Purba. "Reconstruction Of Oil Spill Trajectory In The Java Sea, Indonesia Using Sar Imagery." GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY 14, no. 1 (April 5, 2021): 177–84. http://dx.doi.org/10.24057/2071-9388-2020-21.
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Oil spill phenomena in the ocean possess a very serious threat to ocean health. On the ocean surface, oil slicks immediately start to spread and mostly end up in the ecosystem. Furthermore, it could threaten the organisms living in the ocean or impact nearby coastal area. The aim of this research was to investigate the trajectories of oil spill based on a real accident in the Java Sea. Tracking oil spills using satellite images is an efficient method that provides valuable information about trajectories, locations and the spread intensity. The objective of this study was to periodically track the trajectory of the oil spill from the Karawang incident using Sentinel-1 Synthetic Aperture Radar (SAR) images. Pre-processing of the images consisted of radiometric and geometric corrections. After the corrections, SAR images were mapped and plotted accordingly. To understand the oil spill trajectories in relation to the oceanic processes, the ocean current pattern map and surface wind roses were also analysed. The processed images from July to October 2019 show a trajectory dominated by the oil spill layers movement towards the west to northwest from the original location along with a decrease in the detected oil spill area over time. The identified trajectories of the oil spill followed the ocean current pattern and surface winds. Thus, these two parameters were considered to be the main factors responsible for the oil spill drift.
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Soon, Kok-Soon, Ming-Yih Lee, Chih-Chien Chang, Chun-Hou Wang, and Chih-Feng Lin. "A NEW TRUNK SWAY ASSESSMENT PROTOCOL FOR STROKE PATIENTS USING A BIOFEEDBACK INERTIAL-BASED SENSING MODALITY." Biomedical Engineering: Applications, Basis and Communications 24, no. 05 (October 2012): 461–69. http://dx.doi.org/10.4015/s1016237212500421.
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Brain damage pathology can generate an irrelevant motor program leading to abnormal posture. Given this observation, we tested the hypothesis that postural control deficits are present in individuals with postural disorders. A new trunk sway assessment protocol evaluation system using an inertial-based sensing technique combined with visual-biofeedback strategies was developed. The proposed system was used to assess the angular deviation of the center of mass and enhanced balance control in patients with stroke. Twelve participants with hemiplegia were randomly divided into a visual-biofeedback group (experimental) and a without visual-biofeedback group (control), and were asked to stand as still as possible for 30 s. Postural sway data were submitted to conventional quantitative analyses of sway magnitude using a center of mass measurement. Additionally, group means were compared using parametric tests. Parameters in both the anterior-posterior and medio-lateral directions within the stroke patients were compared using paired t-tests. The experimental group showed increased postural control, indicative of reduced postural sway. Decreased complexity in the medio-lateral direction was also observed in the experimental group, suggesting both a reduction in the dynamic range available for postural control, and that their postural corrections were dominated primarily by longer-term scales. Significant interactions between the diagnostic group and visual condition were also observed for both of these measures, suggesting that the control group participants were impaired in their ability to make corrections to their sway pattern when no visual biofeedback was available. Greater sway magnitude and reduced complexity suggest that individuals with hemiplegia have deficits in sensorimotor integration and a reduced range of timescales available within which to make postural corrections.
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Zhang, Shouwen, Hua Jiang, and Hui Wang. "Assessment of the Sea Surface Temperature Predictability Based on Multimodel Hindcasts." Weather and Forecasting 34, no. 6 (December 1, 2019): 1965–77. http://dx.doi.org/10.1175/waf-d-19-0040.1.
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Abstract Based on historical forecasts of four individual forecasting systems, we conducted multimodel ensembles (MME) to predict the sea surface temperature anomaly (SSTA) variability and assessed these methods from a deterministic and probabilistic point of view. To investigate the advantages and drawbacks of different deterministic MME methods, we used simple averaged MME with equal weighs (SCM) and the stepwise pattern projection method (SPPM). We measured the probabilistic forecast accuracy by Brier skill score (BSS) combined with its two components: reliability (Brel) and resolution (Bres). The results indicated that SCM showed a high predictability in the tropical Pacific Ocean, with a correlation exceeding 0.8 with a 6-month lead time. In general, the SCM outperformed the SPPM in the tropics, while the SPPM tend to show some positive effect on the correction when at long lead times. Corrections occurred for the spring predictability barrier of ENSO, in particular for improvements when the correlation was low or the RMSE was large using the SCM method. These qualitative results are not susceptible to the selection of the hindcast periods, it is as a rule rather by chance of these individual systems. Performance of our probabilistic MME was better than the Climate Forecast System version2 (CFSv2) forecasts in forecasting COLD, NEUTRAL, and WARM SSTA categories for most regions, mainly due to the contribution of Brel, indicating more adequate ensemble construction strategies of the MME system superior to the CFSv2.
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Uyun, Shofwatul, Seto Rahardyan, and Muhammad Anshari. "Skew Correction and Image Cleaning Handwriting Recognition Using a Convolutional Neural Network." JOIV : International Journal on Informatics Visualization 7, no. 3 (September 10, 2023): 681. http://dx.doi.org/10.30630/joiv.7.3.1712.
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Handwriting recognition is a study of Optical Character Recognition (OCR) which has a high level of complexity. In addition, everyone has a unique and inconsistent handwriting style in writing characters upright, affecting recognition success. However, proper pre-processing and classification algorithms affect the success of pattern recognition systems. This paper proposes a pre-processing method for handwriting image recognition using a convolutional neural network (CNN). This study uses public datasets for training and private datasets for testing. This pre-processing consists of three processes: image cleaning, skew correction, and segmentation. These three processes aim to clean the image from unnecessary ink streaks. In addition, to make angle corrections to characters in italics in their writing. The model testing process uses image test data of handwriting that are not straight. There are three images based on the inclination angle: less than 45 degrees, equal to 45 degrees, and more than 45 degrees. Picture cleaning removes unnecessary strokes (noise) from the image using a layer mask, whereas skew correction changes the handwriting to an upright posture based on the detected angle. The pre-processing model we propose worked optimally on handwriting with a skew angle of fewer than 45 degrees and 45 degrees. Our proposed model generally works well for handwriting with fewer than 45 degrees skew with an accuracy of 88,96%. Research with a similar scope can continue to improve optimization with a focus on algorithms related to analysis layout studies. Besides that, it can focus more on automation in the segmentation process of each character.
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Wang, Shu, Xinrong Yan, Yunqiang Zhu, Jia Song, Kai Sun, Weirong Li, Lei Hu, Yanmin Qi, and Huiyao Xu. "New Era for Geo-Parsing to Obtain Actual Locations: A Novel Toponym Correction Method Based on Remote Sensing Images." Remote Sensing 14, no. 19 (September 21, 2022): 4725. http://dx.doi.org/10.3390/rs14194725.
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Geo-parsing, one of the key components of geographical information retrieval, is a process to recognize and geo-locate toponyms mentioned in texts. Such a process can obtain locations contained in toponyms successfully with consistent updating of neural network models and multiple contextual features. The significant offset distance between the geo-parsed locations and the actual occurrence locations still remains. This is because the geo-parsed locations sourced from toponyms in texts always point to the centers of cities, counties, or towns, and cannot directly represent the actual occurrence locations such as factories, farms, and activity areas. Consequently, The significant offset distances between the geo-parsed locations and the actual occurrence locations limit text mining applications in micro-scale geographic discoveries. This research aims at decreasing offset distances of geo-parsed locations by proposing a novel Toponym Correction Method based on satellite Remote Sensing Images (TC-RSI). The TC-RSI method uses satellite remote sensing images to provide extra detailed spatial information that can be associated with the sentence toponym by corresponding attributes. The TC-RSI method was validated in a case study of the forest ecological pattern dataset of An’hui province from visual, statistical, and robustness assessments. The correction results show that the TC-RSI method dramatically decreases the offset distances from about 50 km to about 1 km and promotes geographical discoveries on smaller scales. A series of analyses indicated that the TC-RSI is a valid, effective, and promising method to improve the accuracy of geo-parsed locations, which allows text mining to find more accurate geographical discoveries with lower offset distances. Moreover, toponym correction promotes the use of more diverse spatial data sources, such as Lidar, domain gazetteers, Wikimedia, and streetscapes, which are expected to usher in a new era of geo-parsing with toponym corrections.
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Ngo, Dat, Suhun Ahn, Jeonghyeon Son, and Bongsoon Kang. "Accelerating Pattern Recognition with a High-Precision Hardware Divider Using Binary Logarithms and Regional Error Corrections." Electronics 14, no. 6 (March 7, 2025): 1066. https://doi.org/10.3390/electronics14061066.
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Pattern recognition applications involve extensive arithmetic operations, including additions, multiplications, and divisions. When implemented on resource-constrained edge devices, these operations demand dedicated hardware, with division being the most complex. Conventional hardware dividers, however, incur substantial overhead in terms of resource consumption and latency. To address these limitations, we employ binary logarithms with regional error correction to approximate division operations. By leveraging approximation errors at boundary regions to formulate logarithm and antilogarithm offsets, our approach effectively reduces hardware complexity while minimizing the inherent errors of binary logarithm-based division. Additionally, we propose a six-stage pipelined hardware architecture, synthesized and validated on a Zynq UltraScale+ FPGA platform. The implementation results demonstrate that the proposed divider outperforms conventional division methods in terms of resource utilization and power savings. Furthermore, its application in image dehazing and object detection highlights its potential for real-time, high-performance computing systems.
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Martinez, Ruben D. "Wave propagation effects on amplitude variation with offset measurements: A modeling study." GEOPHYSICS 58, no. 4 (April 1993): 534–43. http://dx.doi.org/10.1190/1.1443436.
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Wave propagation effects can significantly affect amplitude variation with offset (AVO) measurements. These effects include spreading losses, transmission losses, interbed multiples, surface multiple reflections, P‐SV mode converted waves and inelastic attenuation. Examination of prestack elastic synthetic seismograms suggests that spreading losses and the transmission losses plus compressional interbed multiples are manifest mainly as a time and offset effect on the primary reflections. The surface related multiples and the P‐SV mode‐converted waves interfere with prestack amplitudes inducing distortions in the AVO pattern. Such distortions cause large variances in AVO model fitting. Prestack viscoelastic synthetic seismograms also suggest that inelastic attenuation further complicates the AVO response because of the offset and time variant amplitude decay effects and the phase change due to dispersion. Together, all these effects severely alter AVO behavior and result in serious errors in AVO parameter estimates being made from inadequately corrected seismograms. This modeling study suggests that time and offset dependent data processing prior to AVO analysis would be necessary to correct for the wave propagation effects, via either inverse filtering or model based approaches. Comparisons between acoustic and elastic synthetic seismograms show that corrections for the wave propagation effects derived using acoustic approximations are inadequate. Corrections need to be calculated based on elastic approximations provided that the inelastic attenuation effects have been previously removed.
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Pańtak, Marek. "Vertical Dynamic Loads on Footbridges Generated by People Running." Baltic Journal of Road and Bridge Engineering 15, no. 1 (March 17, 2020): 47–75. http://dx.doi.org/10.7250/bjrbe.2020-15.461.
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This paper concerns the issue of the dynamic impact of people running on footbridges with particular with attention to various footstrike patterns occurring during the running (i.e. heel strike pattern and forefoot strike pattern). The results of a series of laboratory tests of vertical ground reaction force (VGRF) measurements generated by running people are presented along with the characteristics of the VGRF curves. Based on the results of the tests, a new proposal for a dynamic load model generated by people classified as heel strike runners has been developed, and corrections of the input parameters of two load models proposed by other authors have been performed. Moreover, the VGRF modelling technique using the Gaussian functions is presented along with a set of equations describing the variability of the Gaussian function parameters as a function of the frequency of running. The presented methods of the VGRF modelling allow increasing the accuracy of determining the VGRF values and, consequently, increasing the accuracy of dynamic analyses of footbridges subjected to dynamic loads generated by people running.
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Alexander, Shalyt-Margolin. "Generalized Uncertainty Principle with Maximal Momentum: QFT, Quantum Black Holes, and Some Cosmological Implications." Nonlinear Phenomena in Complex Systems 25, no. 2 (June 30, 2022): 122–35. http://dx.doi.org/10.33581/1561-4085-2022-25-2-122-135.
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This paper is a continuation of the earlier works written by the author and devoted to studies of the applicability boundary of a quantum field theory (QFT). Based on the results from black hole thermodynamics at all energy scales, this work demonstrates that, provided the Generalized Uncertainty Principle with maximal momentum at Planck scale and without a minimal length for the well-known quantum field theory, there exists a natural ultraviolet applicable boundary(cut-off) distant from the Planck scales. Some important cosmological implications from the obtained results are considered. Specifically, the number of e-folds in the inflation pattern is estimated considering the quantum-gravity corrections. Besides, particular cosmological parameters are evaluated in this case in the explicit form.
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Driemeier, Carlos, and Guilherme A. Calligaris. "Theoretical and experimental developments for accurate determination of crystallinity of cellulose I materials." Journal of Applied Crystallography 44, no. 1 (December 14, 2010): 184–92. http://dx.doi.org/10.1107/s0021889810043955.
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This work defines the crystallinity of cellulose I materials on a dry-weight basis. Theoretical and experimental developments in X-ray diffraction lead to a crystallinity determination method that is estimated to reach 1σ accuracies of better than 0.05 (crystallinity defined between 0 and 1). The method is based on Rietveld modelling, to resolve cellulose I Bragg peaks, and a standard truncated invariant integral. Corrections are derived to account for incoherent scattering, moisture content and other compositional deviations from pure cellulose. The experimental development uses X-ray diffraction in transmission fibre geometry with two-dimensional pattern Rietveld modelling, including a crystal-orientation distribution function. The crystallinities of a few commercial cellulose I materials were determined with the aim of illustrating the applicability of the method.
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SONCINI, MONICA, EMILIANO VOTTA, SILVIA ZINICCHINO, VALERIA BURRONE, ROBERTO FUMERO, ANDREA MANGINI, MASSIMO LEMMA, CARLO ANTONA, and ALBERTO REDAELLI. "FINITE ELEMENT SIMULATIONS OF THE PHYSIOLOGICAL AORTIC ROOT AND VALVE SPARING CORRECTIONS." Journal of Mechanics in Medicine and Biology 06, no. 01 (March 2006): 91–99. http://dx.doi.org/10.1142/s0219519406001790.
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A 3-D model of the aortic root was developed consisting of aortic valve, sinus of Valsalva and aortic duct. Through finite element modeling, the mechanical behavior of the valve was investigated simulating four different configurations: physiological (baseline), aneurysmatic and corrected with two different sparing techniques, named after David and Yacoub, respectively. These surgical procedures imply the replacement of the sinus of Valsalva with a synthetic graft, inside which the cusps are resuspended. The final goal of this study consisted in the assessment of the mechanical effects of sinuses aneurysm on the whole root, as well as the effectiveness of the two aforementioned techniques in restoring valve functionality and normal stress values on the root substructures. Based on the assumption of three-leaflet symmetry, only one third of the aortic root was modeled. Two cardiac cycles were simulated and the mechanical behavior of the aortic root was evaluated in terms of stress pattern, contact pressure and contact areas observed during leaflets coaptation and when contact between the leaflet and the graft occurs. Both the sparing techniques are able to restore coaptation of the aortic valve, but for the David procedure, contact between the leaflet and the graft wall was detected.
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Li, Gen, Zhiyuan Zhang, and Bo Lu. "Effects of Excessive Equatorial Cold Tongue Bias on the Projections of Tropical Pacific Climate Change. Part II: The Extreme El Niño Frequency in CMIP5 Multi-Model Ensemble." Atmosphere 12, no. 7 (June 30, 2021): 851. http://dx.doi.org/10.3390/atmos12070851.
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Under increased greenhouse gas (GHG) forcing, climate models tend to project a warmer sea surface temperature in the eastern equatorial Pacific than in the western equatorial Pacific. This El Niño-like warming pattern may induce an increase in the projected occurrence frequency of extreme El Niño events. The current models, however, commonly suffer from an excessive westward extension of the equatorial Pacific cold tongue accompanied by insufficient equatorial western Pacific precipitation. By comparing the Representative Concentration Pathway (RCP) 8.5 experiments with the historical simulations based on the Coupled Model Intercomparison Project phase 5 (CMIP5), a “present–future” relationship among climate models was identified: models with insufficient equatorial western Pacific precipitation error would have a weaker mean El Niño-like warming pattern as well as a lower increase in the frequency of extreme El Niño events under increased GHG forcing. Using this “present–future” relationship and the observed precipitation in the equatorial western Pacific, this study calibrated the climate projections in the tropical Pacific. The corrected projections showed a stronger El Niño-like pattern of mean changes in the future, consistent with our previous study. In particular, the projected increased occurrence of extreme El Niño events under RCP 8.5 forcing are underestimated by 30–35% in the CMIP5 multi-model ensemble before the corrections. This implies an increased risk of the El Niño-related weather and climate disasters in the future.
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Haagsma, Juanita A., Spencer L. James, Chris D. Castle, Zachary V. Dingels, Jack T. Fox, Erin B. Hamilton, Zichen Liu, et al. "Burden of injury along the development spectrum: associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017." Injury Prevention 26, Supp 1 (January 8, 2020): i12—i26. http://dx.doi.org/10.1136/injuryprev-2019-043296.
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BackgroundThe epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates.MethodsInjury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm—the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate.ResultsFor many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced.ConclusionsThe overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum.
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Heron, Campbell J. Le, Sarah L. Wright, Tracy R. Melzer, Daniel J. Myall, Michael R. MacAskill, Leslie Livingston, Ross J. Keenan, Richard Watts, John C. Dalrymple-Alford, and Tim J. Anderson. "Comparing Cerebral Perfusion in Alzheimer's Disease and Parkinson's Disease Dementia: An ASL-MRI Study." Journal of Cerebral Blood Flow & Metabolism 34, no. 6 (March 12, 2014): 964–70. http://dx.doi.org/10.1038/jcbfm.2014.40.
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Emerging evidence suggests that Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) share neurodegenerative mechanisms. We sought to directly compare cerebral perfusion in these two conditions using arterial spin labeling magnetic resonance imaging (ASL-MRI). In total, 17 AD, 20 PDD, and 37 matched healthy controls completed ASL and structural MRI, and comprehensive neuropsychological testing. Alzheimer's disease and PDD perfusion was analyzed by whole-brain voxel-based analysis (to assess absolute blood flow), a priori specified region of interest analysis, and principal component analysis (to generate a network differentiating the two groups). Corrections were made for cerebral atrophy, age, sex, education, and MRI scanner software version. Analysis of absolute blood flow showed no significant differences between AD and PDD. Comparing each group with controls revealed an overlapping, posterior pattern of hypoperfusion, including posterior cingulate gyrus, precuneus, and occipital regions. The perfusion network that differentiated AD and PDD groups identified relative differences in medial temporal lobes (AD < PDD) and right frontal cortex (PDD < AD). In conclusion, the pattern of cerebral hypoperfusion is very similar in AD and PDD. This suggests closely linked mechanisms of neurodegeneration mediating the evolution of dementia in both conditions.
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Giordano, N. "Understanding end corrections and flow near the open end of a flue instrument." Journal of the Acoustical Society of America 157, no. 2 (February 1, 2025): 1176–84. https://doi.org/10.1121/10.0035834.
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Wind instruments containing a resonator (i.e., pipe) with an open end are expected to exhibit an acoustic standing wave characterized by a density oscillation whose amplitude falls to zero a short distance beyond the end of the resonator. An extrapolation of this amplitude based on the behavior inside the resonator yields an “effective” node of the standing wave (i.e., a point at which the extrapolated amplitude vanishes), and the distance from the end of the resonator to the location of this effective node (which is commonly referred to as simply a “node”) is known as the “end correction.” Recent work using a novel optical technique involving optical speckle patterns surprisingly suggested instead that a node is located inside the resonator with unexpected structure in the standing wave amplitude just beyond the end of the resonator. We have studied this problem by numerically solving the Navier-Stokes equations and find that the effective node of the density oscillation is located at the expected position outside the resonator with no unexpected structure in the functional form of the standing wave. We also show how pressure gradients and the flow pattern found near the end of the resonator can account for the unexpected behavior observed in the experiments. This sensitivity of optical interference effects to flow structure may give a new experimental way to investigate vorticity and other complex flows found in the mouthpiece of a musical instrument and in other situations.
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Nianias, James, Jeremy Lim, and Michael Yeung. "On the Evidence for Molecular Outflows in High-redshift Dusty Star-forming Galaxies." Astrophysical Journal 963, no. 1 (February 23, 2024): 19. http://dx.doi.org/10.3847/1538-4357/ad188a.
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Abstract Galactic-scale outflows of molecular gas from star-forming galaxies constitute the most direct evidence for the regulation of star formation. In the early Universe (z > 4), such outflows have recently been inferred from gravitationally lensed dusty star-forming galaxies (DSFGs) based on ubiquitous detections of OH absorption extending to more blueshifted velocities than [C ii] or CO emission in spatially integrated spectra. Because these lines are redshifted to submillimeter wavelengths, such measurements require careful corrections for atmospheric absorption lines, and a proper accounting of sometimes large variations in measurement uncertainties over these lines. Taking these factors into consideration, we reanalyze OH and [C ii] data taken with the Atacama Large Millimeter/submillimeter Array for five sources where such data are available, of which four were categorised as exhibiting outflows. Based on their spatially integrated spectra alone, we find statistically significant (≥3σ) OH absorption more blueshifted than [C ii] emission in only one source. By contrast, searching channel maps for signals diluted below the detection threshold in spatially integrated spectra, we find evidence for a separate kinematic component in OH absorption in all five sources in the form of (i) more blueshifted OH absorption than [C ii] emission and/or (ii) a component in OH absorption exhibiting a different spatio-kinematic pattern than in [C ii] emission, the latter presumably tracing gas in a rotating disk. Providing a more complete and accurate assessment of molecular outflows in gravitationally lensed DSFGs, we suggest methods to assess the precision of corrections for atmospheric absorption better and to measure the source continuum in future observations more accurately.
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Tamuli, Dibashree, Manpreet Kaur, Tavpritesh Sethi, Anup Singh, Mohammed Faruq, Ashok K. Jaryal, Achal K. Srivastava, Senthil S. Kumaran, and Kishore K. Deepak. "Cortical and Subcortical Brain Area Atrophy in SCA1 and SCA2 Patients in India." Neurology India 69, no. 5 (September 2021): 1318–25. http://dx.doi.org/10.4103/0028-3886.329596.
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Introduction: Genetically defined spinocerebellar ataxia (SCA) type 1 and 2 patients have differential clinical profile along with probable distinctive cortical and subcortical neurodegeneration. We compared the degree of brain atrophy in the two subtypes with their phenotypic and genotypic parameters. Methods: MRI was performed using a 3T scanner (Philips, Achieva) to obtain 3D T1-weighted scans of the whole brain and analyzed by FreeSurfer (version 5.3 and 6 dev.) software. Genetically proven SCA1 (n = 18) and SCA2 (n = 25) patients with age-matched healthy controls (n = 8) were recruited. Clinical severity was assessed by the International Cooperative Ataxia Rating Scale (ICARS). To know the differential pattern of atrophy, the groups were compared using ANOVA/Kruskal-Wallis test and followed by correlation analysis with multiple corrections. Further, machine learning-based classification of SCA subtypes was carried out. Result: We found (i) bilateral frontal, parietal, temporal, and occipital atrophy in SCA1 and SCA2 patients; (ii) reduced volume of cerebellum, regions of brain stem, basal ganglia along with the certain subcortical areas such as hippocampus, amygdala, thalamus, diencephalon, and corpus callosum in SCA1 and SCA2 subtypes; (iii) higher subcortical atrophy SCA2 than SCA1 (iv) correlation between brain atrophy and disease attributes; (v) differential predictive pattern of two SCA subtypes using machine learning approach. Conclusion: The present study suggests that SCA1 and SCA2 do not differ in cortical thinning while a characteristic pattern of subcortical atrophy SCA2 > SCA1 is observed along with correlation of brain atrophy and disease attributes. This may provide the diagnostic guidance of MRI to SCA subtypes and differential therapies.
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Fricke, Katharina, Björn Baschek, Alexander Jenal, Caspar Kneer, Immanuel Weber, Jens Bongartz, Jens Wyrwa, and Andreas Schöl. "Observing Water Surface Temperature from Two Different Airborne Platforms over Temporarily Flooded Wadden Areas at the Elbe Estuary—Methods for Corrections and Analysis." Remote Sensing 13, no. 8 (April 13, 2021): 1489. http://dx.doi.org/10.3390/rs13081489.
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Over the Hahnöfer Nebenelbe, a part of the Elbe estuary near Hamburg, Germany, a combined aerial survey with an unmanned aerial system (UAV) and a gyrocopter was conducted to acquire information about the water surface temperatures. The water temperature in the estuary is important for biological processes and living conditions of riverine organisms. This study aimed to develop a workflow that allows for comparing and analysing surface temperatures acquired by two different remote sensing systems. The thermal infrared (TIR) datasets were compared with in situ measurements gathered during the data acquisition, where both TIR datasets showed a varying bias. Potential error sources regarding the absolute and relative accuracy were investigated and modelled based on the available measurements, including emissivity, atmosphere, skin effect at the water surface, camera flat field correction and calibration. The largest effects on the observed TIR water temperature had the camera calibration and the modelled atmospheric effects. After the correction steps, both datasets could be combined to create a multitemporal representation of the temperature pattern and profiles over the survey area’s wadden flats.
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Hotinli, Selim C., Gilbert P. Holder, Matthew C. Johnson, and Marc Kamionkowski. "Cosmology from the kinetic polarized Sunyaev Zel'dovich effect." Journal of Cosmology and Astroparticle Physics 2022, no. 10 (October 1, 2022): 026. http://dx.doi.org/10.1088/1475-7516/2022/10/026.
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Abstract The cosmic microwave background (CMB) photons that scatter off free electrons in the large-scale structure induce a linear polarization pattern proportional to the remote CMB temperature quadrupole observed in the electrons' rest frame. The associated blackbody polarization anisotropies are known as the polarized Sunyaev Zel'dovich (pSZ) effect. Relativistic corrections to the remote quadrupole field give rise to a non-blackbody polarization anisotropy proportional to the square of the transverse peculiar velocity field; this is the kinetic polarized Sunyaev Zel'dovich (kpSZ) effect. In this paper, we forecast the ability of future CMB and galaxy surveys to detect the kpSZ effect, finding that a statistically significant detection is within the reach of planned experiments. We further introduce a quadratic estimator for the square of the peculiar velocity field based on a galaxy survey and CMB polarization. Finally, we outline how the kpSZ effect is a probe of cosmic birefringence and primordial non-Gaussianity, forecasting the reach of future experiments.
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Barnston, Anthony G., Simon J. Mason, Lisa Goddard, David G. DeWitt, and Stephen E. Zebiak. "Multimodel Ensembling in Seasonal Climate Forecasting at IRI." Bulletin of the American Meteorological Society 84, no. 12 (December 1, 2003): 1783–96. http://dx.doi.org/10.1175/bams-84-12-1783.
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The International Research Institute (IRI) for Climate Prediction seasonal forecast system is based largely on the predictions of ensembles of several atmospheric general circulation models (AGCMs) forced by two versions of an SST prediction—one consisting of persisted SST anomalies from the current observations and one of evolving SST anomalies as predicted by a set of dynamical and statistical SST prediction models. Recently, an objective multimodel ensembling procedure has replaced a more laborious and subjective weighting of the predictions of the several AGCMs. Here the skills of the multimodel predictions produced retrospectively over the first 4 years of IRI forecasts are examined and compared with the skills of the more subjectively derived forecasts actually issued. The multimodel ensemble predictions are generally found to be an acceptable replacement, although the precipitation forecasts do benefit from inclusion of empirical forecast tools. Planned pattern-level model output statistics (MOS) corrections for systematic biases in the AGCM forecasts may render them more sufficient in their own right.
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Maksimov, A. O., and T. G. Leighton. "Pattern formation on the surface of a bubble driven by an acoustic field." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, no. 2137 (August 17, 2011): 57–75. http://dx.doi.org/10.1098/rspa.2011.0366.
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The final stable shape taken by a fluid–fluid interface when it experiences a growing instability can be important in determining features as diverse as weather patterns in the atmosphere and oceans, the growth of cell structures and viruses, and the dynamics of planets and stars. An example which is accessible to laboratory study is that of an air bubble driven by ultrasound when it becomes shape-unstable through a parametric instability. Above the critical driving pressure threshold for shape oscillations, which is minimal at the resonance of the breathing mode, regular patterns of surface waves are observed on the bubble wall. The existing theoretical models, which take account only of the interaction between the breathing and distortion modes, cannot explain the selection of the regular pattern on the bubble wall. This paper proposes an explanation which is based on the consideration of a three-wave resonant interaction between the distortion modes. Using a Hamiltonian approach to nonlinear bubble oscillation, corrections to the dynamical equations governing the evolution of the amplitudes of interacting surface modes have been derived. Steady-state solutions of these equations describe the formation of a regular structure. Our predictions are confirmed by images of patterns observed on the bubble wall.
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Ecker, Ullrich K. H., Brandon K. N. Sze, and Matthew Andreotta. "Corrections of political misinformation: no evidence for an effect of partisan worldview in a US convenience sample." Philosophical Transactions of the Royal Society B: Biological Sciences 376, no. 1822 (February 22, 2021): 20200145. http://dx.doi.org/10.1098/rstb.2020.0145.
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Misinformation often has a continuing effect on people's reasoning despite clear correction. One factor assumed to affect post-correction reliance on misinformation is worldview-driven motivated reasoning. For example, a recent study with an Australian undergraduate sample found that when politically situated misinformation was retracted, political partisanship influenced the effectiveness of the retraction. This worldview effect was asymmetrical, that is, particularly pronounced in politically conservative participants. However, the evidence regarding such worldview effects (and their symmetry) has been inconsistent. Thus, the present study aimed to extend previous findings by examining a sample of 429 pre-screened US participants supporting either the Democratic or Republican Party. Participants received misinformation suggesting that politicians of either party were more likely to commit embezzlement; this was or was not subsequently retracted, and participants' inferential reasoning was measured. While political worldview (i.e. partisanship) influenced the extent to which participants relied on the misinformation overall, retractions were equally effective across all conditions. There was no impact of political worldview on retraction effectiveness, let alone evidence of a backfire effect, and thus we did not replicate the asymmetry observed in the Australian-based study. This pattern emerged despite some evidence that Republicans showed a stronger emotional response than Democrats to worldview-incongruent misinformation. This article is part of the theme issue ‘The political brain: neurocognitive and computational mechanisms’.
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Hutton, L. K., and David M. Boore. "The ML scale in Southern California." Bulletin of the Seismological Society of America 77, no. 6 (December 1, 1987): 2074–94. http://dx.doi.org/10.1785/bssa0770062074.
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Abstract Measurements (9,941) of peak amplitudes on Wood-Anderson instruments (or simulated Wood-Anderson instruments) in the Southern California Seismographic Network for 972 earthquakes, primarily located in southern California, were studied with the aim of determining a new distance correction curve for use in determining the local magnitude, ML. Events in the Mammoth Lakes area were found to give an unusual attenuation pattern and were excluded from the analysis, as were readings from any one earthquake at distances beyond the first occurrence of amplitudes less than 0.3 mm. The remaining 7,355 amplitudes from 814 earthquakes yielded the following equation for ML distance correction, log A0 − log A 0 = 1.110 log ( r / 100 ) + 0.00189 ( r − 100 ) + 3.0 where r is hypocentral distance in kilometers. A new set of station corrections was also determined from the analysis. The standard deviation of the ML residuals obtained by using this curve and the station corrections was 0.21. The data used to derive the equation came from earthquakes with hypocentral distances ranging from about 10 to 700 km and focal depths down to 20 km (with most depths less than 10 km). The log A0 values from this equation are similar to the standard values listed in Richter (1958) for 50 < r < 200 km (in accordance with the definition of ML, the log A0 value for r = 100 km was constrained to equal his value). The Wood-Anderson amplitudes decay less rapidly, however, than implied by Richter's correction. Because of this, the routinely determined magnitudes have been too low for nearby stations (r < 50 km) and too high for distant stations (r > 200 km). The effect at close distances is consistent with that found in several other studies, and is simply due to a difference in the observed ≈ 1/r geometrical spreading for body waves and the 1/r2 spreading assumed by Gutenberg and Richter in the construction of the log A0 table. ML's computed from our curve and those reported in the Caltech catalog show a systematic dependence on magnitude: small earthquakes have larger magnitudes than in the catalog and large earthquakes have smaller magnitudes (by as much as 0.6 units). To a large extent, these systematic differences are due to the nonuniform distribution of data in magnitude-distance space (small earthquakes are preferentially recorded at close distances relative to large earthquakes). For large earthquakes, however, the difference in the two magnitudes is not solely due to the new correction for attenuation; magnitudes computed using Richter's log A0 curve are also low relative to the catalog values. The differences in that case may be due to subjective judgment on the part of those determining the catalog magnitudes, the use of data other than the Caltech Wood-Anderson seismographs, the use of different station corrections, or the use of teleseismic magnitude determinations. Whatever their cause, the departures at large magnitude may explain a 1.0:0.7 proportionality found by Luco (1982) between ML's determined from real Wood-Anderson records and those from records synthesized from strong-motion instruments. If it were not for the biases in reported magnitudes, Luco's finding would imply a magnitude-dependent shape in the attenuation curves. We studied residuals in three magnitude classes (2.0 < ML ≦ 3.5, 3.5 < ML ≦ 5.5, and 5.5 < ML ≦ 7.0) and found no support for such a magnitude dependence. Based on our results, we propose that local magnitude scales be defined such that ML = 3 correspond to 10 mm of motion on a Wood-Anderson instrument at 17 km hypocentral distance, rather than 1 mm of motion at 100 km. This is consistent with the original definition of magnitude in southern California and will allow more meaningful comparison of earthquakes in regions having very different attenuation of waves within the first 100 km.
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SHUMLIANSKA, Liudmyla, and Petro PIGULEVSKIY. "CONSTRUCTION AND FIRST INTERPRETATION RESULTS OF THE THREE-DIMENSIONAL MANTLE DENSITY MODEL UNDER THE UKRAINIAN SHIELD." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 2 (105) (2024): 21–28. http://dx.doi.org/10.17721/1728-2713.105.03.
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Background. Mantle density models are key tools for understanding fundamental geological and physical processes occurring within the Earth. Many parameters used in mantle density models remain poorly understood and undefined. Among others, these include data on the composition and rheology of the mantle, which can vary significantly. Methods. The method of creating density models (density) significantly influences the final result. Modeling with one-dimensional models simplifies the calculation process but generalizes the distribution of mantle density, assuming it is homogeneous in the horizontal direction. This limitation does not allow for the consideration of lateral variations in mantle density, which can be important at the regional level. In this study, we present a quasi-three-dimensional model of mantle density beneath the Ukrainian Shield, obtained on the basis of a set of one-dimensional density curves. Polynomial corrections for heterogeneity were applied during the calculations, compensating for the shortcomings of one-dimensional models. This three-dimensional model was derived by recalculating one-dimensional velocity curves obtained by seismic tomography for 21 mantle domains in the depth range of 50 to 2600 km. The process of transforming P-wave velocity curves into a density model includes the following steps: determining seismic boundaries in the mantle as points of inflection of the first derivative of P-wave velocity curves for each mantle domain; creating a synthetic S-wave mantle model beneath the Ukrainian Shield by recalculating P-wave velocity curves; solving the Adams-Williamson equation using seismic velocities (P, S) for each domain with subsequent polynomial correction to account for heterogeneity; selecting a reference mantle model that would serve as the basis for converting velocity curves into density through the comparison of gravitational potential on the Earth's surface and calculated values from existing reference mantle models (PREM, PREMA, PREMC, IASP91 AK135). The AK135 model was chosen as the reference model based on the comparison of calculated and observed gravitational potential at the central point of the Ukrainian Shield. This study focuses on the final stages of constructing the mantle density model, taking into account mass balancing of the upper and lower mantle for each domain when determining density using the Adams-Williamson equation and introducing polynomial corrections relative to the AK135 reference model; calculating densities for each of the 21 mantle domains and their three-dimensional integration. Results. In this study, we present a quasi-three-dimensional model of mantle density beneath the Ukrainian Shield, obtained on the basis of a set of one-dimensional density curves, with polynomial corrections for inhomogeneity incorporated into the calculations, compensating for the shortcomings of one-dimensional model calculations. This three-dimensional model was obtained by recalculating one-dimensional velocity curves obtained by the seismic tomography method for P-waves, calculated for 21 mantle domains in the depth range from 50 to 2600 km. Conclusions. This study focuses on the final stages of constructing the mantle density model, considering balancing the mass of the upper and lower mantle for each domain in determining density using the Adams-Williamson equation and introducing polynomial corrections relative to the AK135 reference model; calculating densities for each of the 21 mantle domains and their three-dimensional integration. The obtained mantle density model of the Ukrainian Shield is well aligned with the division of the mantle into three main layers: lithosphere, upper mantle, and lower mantle. Each of the structural layers has its own visual pattern of density heterogeneity.
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Xu, Xiaojie, and Yun Zhang. "Dynamic Relationships among Composite Property Prices of Major Chinese Cities: Contemporaneous Causality through Vector Error Corrections and Directed Acyclic Graphs." International Journal of Real Estate Studies 17, no. 1 (June 30, 2023): 148–57. http://dx.doi.org/10.11113/intrest.v17n1.294.
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The present study is the first one that investigates dynamic relations among composite real estate price indices of ten different cities in China during the years from 2005 to 2021. Utilizing the data recorded on a monthly basis, we apply VECM (vector error-correction modeling) and DAGs (directed acyclic graphs) in order to characterize contemporaneous causal relations among the ten real estate price indices. We use the PC algorithm to identify a pattern with non-directed edges and the LiNGAM algorithm to determine the causal ordering, based on which we calculate the results of innovation accounting. The LiNGAM algorithm adopted here effectively utilizes non-normality for facilitating the arrival of complete causal orderings. Our results show that price dynamics revealed through processes of price adjustments due to shocks to prices are rather sophisticated and such dynamics are, in general, dominated by price indices of Shanghai and Shenzhen, which are two top-tier cities among the four top-tier cities in China. This indicates that policy design on composite property prices should be focusing on price indices of Shanghai and Shenzhen.
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., Imalah. "LEGAL AWARENESS DEVELOPMENT MODEL THROUGH A RELIGIOUS APPROACH." JURNAL SETIA PANCASILA 3, no. 2 (February 9, 2023): 20–28. http://dx.doi.org/10.36379/jsp.v3i2.350.
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The high recidivism in Indonesia based on data from the ministry of law and human rights in 2020 amounted to 18.12% or around 24 thousand people clearly demands strategic policy steps in order to reduce the level of recidivism in Indonesia, the Sumenep Class IIB State Detention Center as a technical implementing unit under the auspices of the Directorate General Corrections Department of Law and Human Rights of the Republic of Indonesia where the main task and function is to provide guidance in order to ensure positive behavior changes. The purpose of this study was to find out how the pattern of fostering legal awareness through a religious approach at the Sumenep Class II-B State Detention Center and how the legal awareness of the inmates after coaching is carried out. Through a qualitative approach, data is obtained through observation, interviews, and documentation. The findings of this study indicate that the pattern of fostering inmates at the Sumenep Class II-B State Detention Center is carried out using personality and independence development methods by using special methods such as religious approaches by increasing the legal awareness of inmates,habituating behavior such as disciplinary habits the five daily prayers and congregational prayers, routine recitation, reading and writing of the Qur'an, and istighasah are relatively high and have a very significantimpact on increasing the legal awareness of inmates in the Sumenep Class II-B State Detention Center.
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Knowles, Adam T., A. E. Sansom, C. Allende Prieto, and A. Vazdekis. "sMILES: a library of semi-empirical MILES stellar spectra with variable [α/Fe] abundances." Monthly Notices of the Royal Astronomical Society 504, no. 2 (April 10, 2021): 2286–311. http://dx.doi.org/10.1093/mnras/stab1001.
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ABSTRACT We present a new library of semi-empirical stellar spectra that is based on the empirical Medium resolution Isaac Newton Library of Empirical Spectra (MILES) library. A new, high-resolution library of theoretical stellar spectra is generated that is specifically designed for use in stellar population studies. We test these models across their full wavelength range against other model libraries and find reasonable agreement in their predictions of spectral changes due to atmospheric α-element variations, known as differential corrections. We also test the models against the MILES and MaStar libraries of empirical stellar spectra and also find reasonable agreements, as expected from previous work. We then use the abundance pattern predictions of the new theoretical stellar spectra to differentially correct MILES spectra to create semi-empirical MILES (sMILES) star spectra with abundance patterns that differ from those present in the Milky Way. The final result is five families of 801 sMILES stars with [α/Fe] abundances ranging from −0.20 to 0.60 dex at MILES resolution (FWHM = $2.5\,$Å) and wavelength coverage ($3540.5\!-\!7409.6\,$Å). We make the sMILES library publicly available.
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Liskinasih, Ayu. "CORRECTIVE FEEDBACKS INTERACTION IN CLT-ADOPTED CLASSROOMS." Indonesian Journal of Applied Linguistics 6, no. 1 (July 29, 2016): 60. http://dx.doi.org/10.17509/ijal.v6i1.2662.
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<p>This case study aimed to examine corrective feedback (CF) pattern in the interactions of Indonesian EFL (English as Foreign Language) classrooms (a speaking and a grammar classrooms) which adopt CLT (Communicative Language Teaching). Two lecturers and twenty undergraduate English department students of an A-class university in Indonesia were involved as research participants. The findings revealed that the lecturers employed all types of CF to treat all types of errors. Explicit corrections were dominant in Speaking class as well as other explicit CF; whereas reformulations and prompt were equally distributed. Elicitation was dominant in Grammar class as well as other prompts; meanwhile, explicit and implicit CFs had similar proportion. The lecturers’ preferences were based on their beliefs on how their students learn foreign language and some factors such as the importance of CF to the instructional focus of the lesson, the possibility to generate student’s uptake, and also their empathetic values about students’ current language development. It was concluded that the provisions of CF in EFL classrooms reflect the application of CLT.</p>
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Karlsen, Silje Solheim. "Fridtjof Nansen’s Farthest North: Scientific Report or Personal Account?" Nordlit 12, no. 1 (February 1, 2008): 195. http://dx.doi.org/10.7557/13.1233.
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Being an exploration account from the 19th century, Farthest North is on the one hand an objective account based on facts and details. To prove the route, the final destination and the scientific results - and emphasise that all these experiences were true - the book gives a detailed account of all preparations and equipment, the designs for the ship, temperature, the ice-drifting, the soundings, the gathering of different sea animals, etc. The discourse is represented by tables of scientific results and measures, new mappings and corrections of old maps. Photographs and illustrations, some of them even by Nansen himself, contribute to reinforce the truthfulness of the account. On the other hand, the travelogue gives evidence of a dramatic and outstanding expedition, and is a story about courage, strength and an almost unbelievable deed, which ended in the farthest north record of the time. In particular, the fifteen months' sleigh journey undertaken by Fridtjof Nansen and Hjalmar Johansen is adventurous. This part of the narrative resembles the pattern we find in other kinds of popular literature.
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Wheatley, Spencer, Didier Sornette, Tobias Huber, Max Reppen, and Robert N. Gantner. "Are Bitcoin bubbles predictable? Combining a generalized Metcalfe’s Law and the Log-Periodic Power Law Singularity model." Royal Society Open Science 6, no. 6 (June 2019): 180538. http://dx.doi.org/10.1098/rsos.180538.
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We develop a strong diagnostic for bubbles and crashes in Bitcoin, by analysing the coincidence (and its absence) of fundamental and technical indicators. Using a generalized Metcalfe’s Law based on network properties, a fundamental value is quantified and shown to be heavily exceeded, on at least four occasions, by bubbles that grow and burst. In these bubbles, we detect a universal super-exponential unsustainable growth. We model this universal pattern with the Log-Periodic Power Law Singularity (LPPLS) model, which parsimoniously captures diverse positive feedback phenomena, such as herding and imitation. The LPPLS model is shown to provide an ex ante warning of market instabilities, quantifying a high crash hazard and probabilistic bracket of the crash time consistent with the actual corrections; although, as always, the precise time and trigger (which straw breaks the camel’s back) is exogenous and unpredictable. Looking forward, our analysis identifies a substantial but not unprecedented overvaluation in the price of Bitcoin, suggesting many months of volatile sideways Bitcoin prices ahead (from the time of writing, March 2018).
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BALSA, THOMAS F. "Secondary flow in a Hele-Shaw cell." Journal of Fluid Mechanics 372 (October 10, 1998): 25–44. http://dx.doi.org/10.1017/s0022112098002171.
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We examine the flow in a horizontal Hele-Shaw cell in which the undisturbed unidirectional flow at infinity is required to stream around a vertical cylinder spanning the gap between the two (horizontal) plates of the cell. A combination of matched asymptotic expansions and numerical methods is employed to elucidate the structure of the boundary layer near the surface of the cylinder. The two length scales of the problem are the gap, h, and the length of the body, l; it is assumed that h/l<<1. The characteristic Reynolds number based on l is O(1). The length scales associated with the boundary layer and the classical Hele-Shaw flow pattern are O(h) and O(l), respectively.It is found that the boundary layer contains streamwise vorticity. This vorticity is generated at the three no-slip surfaces (the two plates and the cylinder wall) as a result of the cross-flow induced by the streamwise acceleration/deceleration of the flow around the curved cylinder. The strength of the secondary flow, hence the associated streamwise vorticity, is proportional to changes in body curvature. The validity of the classical Hele-Shaw flow is examined systematically, and higher-order corrections are worked out. This results in a displacement thickness that is roughly 30% of the gap. In other words, the lowest-order correction to the classical Hele-Shaw flow may be obtained by requiring the outer flow (on the scale O(l)) to satisfy the no-penetration boundary condition on a displaced cylinder surface. The boundary layer contains ‘corner’ vortices at the intersections of the horizontal plates and the vertical cylinder surface.
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Menegatt, Jean Carlo Olivo, Fernanda Felicetti Perosa, Anderson Hentz Gris, Manoela Marchezan Piva, Guilherme Carvalho Serena, Diego Luiz Bordignon, Carolina Reck, Álvaro Menin, Tatiane Terumi Negrão Watanabe, and David Driemeier. "Main Causes of Death in Piglets from Different Brazilian Nursery Farms Based on Clinical, Microbiological, and Pathological Aspects." Animals 13, no. 24 (December 11, 2023): 3819. http://dx.doi.org/10.3390/ani13243819.
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Necropsies can reveal herd problems or comorbidities that can lead to management corrections, improvements in animal performance, and better decision making. Furthermore, the pattern and causes of mortality might differ when different systems are evaluated. The present study was conducted to establish the main causes of death in nursery pigs from different systems in Brazil, as well as the clinical, microbiological, and pathological aspects of these mortalities. Eighteen nurseries were analyzed (a total of 120,243 housed piglets), and 557 necropsies were performed. Streptococcus suis infection was the most prevalent cause of death (21.2%), followed by bacterial polyserositis (16.7%), chronic atrophic enteritis (13.5%), salmonellosis (8.8%), pneumonia (8.6%), and colibacillosis (6.1%). The increase in mortality rate in individual nurseries and, consequently, in the diagnoses was commonly associated with disease outbreaks. Infectious diseases constituted the largest portion of the diagnoses, making a great opportunity for improving production rates in herds. Moreover, the extensive range of observed diagnoses highlights the importance of conducting preliminary diagnostic investigations based on necropsy to determine the causes of death. This approach allows for the direction of complementary tests, which can diagnose agents with greater specificity. As a result, this allows for the implementation of more effective prevention and control strategies.
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Kaiser, A. E., H. Horstmeyer, A. G. Green, F. M. Campbell, R. M. Langridge, and A. F. McClymont. "Detailed images of the shallow Alpine Fault Zone, New Zealand, determined from narrow-azimuth 3D seismic reflection data." GEOPHYSICS 76, no. 1 (January 2011): B19—B32. http://dx.doi.org/10.1190/1.3515920.
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Previous high-resolution seismic reflection investigations of active faults have been based on 2D profiles. Unfortunately, 2D data may be contaminated by out-of-the-plane reflections and diffractions that may be difficult to identify and eliminate. Although full 3D seismic reflection methods allow out-of-the-plane events to be recognized and provide superior resolution to 2D methods, they are only rarely applied in environmental and engineering studies because of high costs. A narrow-azimuth 3D acquisition and processing strategy is introduced to produce a high-resolution seismic reflection volume centered on the Alpine Fault Zone (New Zealand). The shallow 3D images reveal late Quaternary deformation structures associated with this major transpressional plate-boundary fault. The relatively inexpensive narrow-azimuth 3D acquisition pattern consisting of inline source and receiver lines was easily implemented in the field to provide 2- by [Formula: see text] CMP coverage over an approximately 500- by [Formula: see text] area.The narrow-azimuth acquisition strategy was well suited for resolving complex structures within the fault zone. Challenges in processing the data were amplified by the effects of strong velocity heterogeneity in the near surface and the presence of complex dipping, diffracted, and truncated events. A carefully tailored processing scheme including surface-consistent deconvolution, refraction static corrections, noise reduction, dip moveout (DMO) corrections, and 3D depth migration greatly improved the appearance of the final stacks. The 3D images reveal strong reflections from the faulted and folded late Pleistocene erosional basement surface. A steeply dipping planar main (dominant) fault strand can be inferred from the geometry and truncations of the overlying postglacial sediments. The 3D images reveal that the average apparent vertical displacement [Formula: see text] of the basement surface across the dominant fault strand at this location is somewhat less than that estimated from a pilot 2D seismic reflection profile, suggesting that the provisional dip-slip rate based on the 2D data is a maximum.
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Tarquini, Simone, and Pietro Armienti. "QUICK DETERMINATION OF CRYSTAL SIZE DISTRIBUTIONS OF ROCKS BY MEANS OF A COLOR SCANNER." Image Analysis & Stereology 22, no. 1 (May 3, 2011): 27. http://dx.doi.org/10.5566/ias.v22.p27-34.
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An acquisition and analysis method based on a commercial, low-cost, high-resolution film scanner is presented. It allows to collect data from standard rock thin sections with a resolution up to 9.4 μm per pixel. Common and general purpose facilities (scanner + PC + image analysis software) may thus be transformed in an appropriate tool for quantitative textural analysis of rocks. The procedure implies the acquisition of four images with crossed polarizers and one parallel light image. Crystal boundaries are extracted from fields in crossed polarizers, while markers for mineral recognition are obtained thresholding the parallel light image. The method is tested for fresh rocks with simple mineralogy (harzburgites and marbles) with no more than three phases, all exhibiting well distinct optical properties. Image processing is performed developing procedures with VISILOG 5.2 package. 2-D size data from binary images are converted to 3-D size data applying stereological corrections. 3-D data are reported in bi-logarithmic diagrams, plotting the crystal number density versus characteristic lengths. The harzburgite samples show a scale invariance of size distributions of olivine while mosaic equant marbles exhibit a different size distribution pattern, without scale invariance and a relative maximum.