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Kernel density

Jin Xie, Fan Zhu, Guoxian Dai, Ling Shao, Yi Fang
Since there are complex geometric variations with 3D shapes, extracting efficient 3D shape features is one of the most challenging tasks in shape matching and retrieval. In this paper, we propose a deep shape descriptor by learning shape distributions at different diffusion time via a progressive shape-distribution-encoder (PSDE). First, we develop a shape distribution representation with the kernel density estimator to characterize the intrinsic geometry structures of 3D shapes. Then, we propose to learn a deep shape feature through an unsupervised PSDE...
January 10, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Salvador A Gezan, Luis F Osorio, Sujeet Verma, Vance M Whitaker
The primary goal of genomic selection is to increase genetic gains for complex traits by predicting performance of individuals for which phenotypic data are not available. The objective of this study was to experimentally evaluate the potential of genomic selection in strawberry breeding and to define a strategy for its implementation. Four clonally replicated field trials, two in each of 2 years comprised of a total of 1628 individuals, were established in 2013-2014 and 2014-2015. Five complex yield and fruit quality traits with moderate to low heritability were assessed in each trial...
2017: Horticulture Research
James Robins, Lingling Li, Eric Tchetgen, Aad van der Vaart
We prove conditional asymptotic normality of a class of quadratic U-statistics that are dominated by their degenerate second order part and have kernels that change with the number of observations. These statistics arise in the construction of estimators in high-dimensional semi- and non-parametric models, and in the construction of nonparametric confidence sets. This is illustrated by estimation of the integral of a square of a density or regression function, and estimation of the mean response with missing data...
December 2016: Stochastic Processes and Their Applications
Sagar Sopanrao Muley, Tanaji Nandgude, Sushilkumar Poddar
BACKGROUND: In the present study, Lansoprazole pellets were prepared employing a novel excipient Carboxymethyl tamarind kernel powder (CMTKP) using extrusion-spheronization technique. Pellet formulation was optimized for formulation parameters (concentration of microcrystalline cellulose, CMTKP, croscarmellose sodium and isopropyl alcohol). METHODS: Process parameters (speed and duration of spheronization) were optimized using factorial design. The pellets were evaluated for yield, bulk and tapped density, particle size, hardness, drug content, disintegration time and drug release...
January 13, 2017: Recent Patents on Drug Delivery & Formulation
Federico Adolfi, Blas Couto, Fabian Richter, Jean Decety, Jessica Lopez, Mariano Sigman, Facundo Manes, Agustín Ibáñez
Guided by indirect evidence, recent approaches propose a tripartite crosstalk among interoceptive signaling, emotional regulation, and low-level social cognition. Here we examined the neurocognitive convergence of such domains. First, we performed three meta-analyses of functional magnetic resonance imaging studies to identify which areas are consistently coactivated by these three systems. Multi-level Kernel Density Analysis (MKDA) revealed major overlaps in the right anterior insular and frontotemporal regions (viz...
December 29, 2016: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Jing Huang, Ye Mei, Gerhard Koenig, Andrew C Simmonett, Frank C Pickard, Qin Wu, Lee-Ping Wang, Alexander D MacKerell, Bernard R Brooks, Yihan Shao
In this work, we report two polarizable molecular mechanics (polMM) force field models for estimating the polarization energy in hybrid quantum mechanical molecular mechanical (QM/MM) calculations. These two models, named the potential of atomic charges (PAC) and potential of atomic dipoles (PAD), are formulated from the ab initio quantum mechanical (QM) response kernels for the prediction of the QM density response to an external molecular mechanical (MM) environment (as described by external point charges)...
January 12, 2017: Journal of Chemical Theory and Computation
Stefan M Schulz
Interoception is the ability to perceive one's internal body state including visceral sensations. Heart-focused interoception has received particular attention, in part due to a readily available task for behavioural assessment, but also due to accumulating evidence for a significant role in emotional experience, decision-making and clinical disorders such as anxiety and depression. Improved understanding of the underlying neural correlates is important to promote development of anatomical-functional models and suitable intervention strategies...
November 19, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
J Aissa, C Thomas, L M Sawicki, J Caspers, P Kröpil, G Antoch, J Boos
AIM: To investigate the value of dedicated computed tomography (CT) iterative metal artefact reduction (iMAR) algorithms in patients after spinal instrumentation. MATERIALS AND METHODS: Post-surgical spinal CT images of 24 patients performed between March 2015 and July 2016 were retrospectively included. Images were reconstructed with standard weighted filtered back projection (WFBP) and with two dedicated iMAR algorithms (iMAR-Algo1, adjusted to spinal instrumentations and iMAR-Algo2, adjusted to large metallic hip implants) using a medium smooth kernel (B30f) and a sharp kernel (B70f)...
January 5, 2017: Clinical Radiology
Pablo A Reyes-Castro, Robin B Harris, Heidi E Brown, Gary L Christopherson, Kacey C Ernst
Little is currently known about the spatial-temporal dynamics of dengue epidemics in arid areas. This study assesses dengue outbreaks that occurred in two arid cities of Mexico, Hermosillo and Navojoa, located in northern state of Sonora. Laboratory confirmed dengue cases from Hermosillo (N=2730) and Navojoa (N=493) were geocoded by residence and assigned neighborhood-level characteristics from the 2010 Mexican census. Kernel density and Space-time cluster analysis was performed to detect high density areas and space-time clusters of dengue...
January 3, 2017: Acta Tropica
Michael Robert Smith, Robert Lee Davis, Patricia Anne Phillips, Tatyana Shvilkina, Kamalijit Kaur, Heather Katrina Tabolt, Matthew Krause, Vincent Galdi
PREMISE: Although trauma may be considered a random act, geographical patterns of trauma potentially emerge. Our institution is unique in that it rests at an intersection of two of the highest areas of poverty and assault in New York City and has adequate data to analyze these patterns. METHODS: We review the incident reports logged by emergency medical services (EMS) technicians arriving with intentionally injured trauma patients from January 1 to December 31, 2013 at a single institution...
February 2017: Annals of Surgery
Guibiao Xu, Bao-Gang Hu, Jose C Principe
The correntropy-induced loss (C-loss) function has the nice property of being robust to outliers. In this paper, we study the C-loss kernel classifier with the Tikhonov regularization term, which is used to avoid overfitting. After using the half-quadratic optimization algorithm, which converges much faster than the gradient optimization algorithm, we find out that the resulting C-loss kernel classifier is equivalent to an iterative weighted least square support vector machine (LS-SVM). This relationship helps explain the robustness of iterative weighted LS-SVM from the correntropy and density estimation perspectives...
December 29, 2016: IEEE Transactions on Neural Networks and Learning Systems
M Glitzner, M Fast, B Denis de Senneville, S Nill, U Oelfke, J Lagendijk, B Raaymakers, S Crijns
PURPOSE: To develop an auto-adaptive margin generator for MLC tracking. The generator is able to estimate errors arising in image guided radiotherapy, particularly on an MR-Linac, which depend on the latencies of machine and image processing, as well as on patient motion characteristics. From the estimated error distribution, a segment margin is generated, able to compensate errors up to a user-defined confidence. METHOD: In every tracking control cycle (TCC, 40ms), the desired aperture D(t) is compared to the actual aperture A(t), a delayed and imperfect representation of D(t)...
June 2016: Medical Physics
G Michalak, A Halaweish, B Krauss, J Fletcher, C McCollough
PURPOSE: Dual energy (DE) CT can be used to characterize tissue composition. One application of DE CT is to measure electron density (ED, rho) and atomic number (Z) for use in radiation therapy treatment planning. This work evaluated the accuracy and stability of ED estimation as patient size varied for both single-energy (SE) and DE CT. METHODS: An ED phantom (CIRS) and four torso-shaped water tanks (lateral widths 15, 25, 35 and 45 cm) containing 8 tissue-simulating cylinders of known ED were scanned on a dual-source CT system (Siemens Somatom Force) in SE (120 kV) and DE (90/150Sn) modes...
June 2016: Medical Physics
J Fan, J Fan, W Hu, J Wang
PURPOSE: To develop a fast automatic algorithm based on the two dimensional kernel density estimation (2D KDE) to predict the dose-volume histogram (DVH) which can be employed for the investigation of radiotherapy quality assurance and automatic treatment planning. METHODS: We propose a machine learning method that uses previous treatment plans to predict the DVH. The key to the approach is the framing of DVH in a probabilistic setting. The training consists of estimating, from the patients in the training set, the joint probability distribution of the dose and the predictive features...
June 2016: Medical Physics
Ronaldo G Morato, Jared A Stabach, Chris H Fleming, Justin M Calabrese, Rogério C De Paula, Kátia M P M Ferraz, Daniel L Z Kantek, Selma S Miyazaki, Thadeu D C Pereira, Gediendson R Araujo, Agustin Paviolo, Carlos De Angelo, Mario S Di Bitetti, Paula Cruz, Fernando Lima, Laury Cullen, Denis A Sana, Emiliano E Ramalho, Marina M Carvalho, Fábio H S Soares, Barbara Zimbres, Marina X Silva, Marcela D F Moraes, Alexandre Vogliotti, Joares A May, Mario Haberfeld, Lilian Rampim, Leonardo Sartorello, Milton C Ribeiro, Peter Leimgruber
Accurately estimating home range and understanding movement behavior can provide important information on ecological processes. Advances in data collection and analysis have improved our ability to estimate home range and movement parameters, both of which have the potential to impact species conservation. Fitting continuous-time movement model to data and incorporating the autocorrelated kernel density estimator (AKDE), we investigated range residency of forty-four jaguars fit with GPS collars across five biomes in Brazil and Argentina...
2016: PloS One
Paulo F C Tilles, Sergei V Petrovskii, Paulo L Natti
Animals do not move all the time but alternate the period of actual movement (foraging) with periods of rest (e.g. eating or sleeping). Although the existence of rest times is widely acknowledged in the literature and has even become a focus of increased attention recently, the theoretical approaches to describe animal movement by calculating the dispersal kernel and/or the mean squared displacement (MSD) rarely take rests into account. In this study, we aim to bridge this gap. We consider a composite stochastic process where the periods of active dispersal or 'bouts' (described by a certain baseline probability density function (pdf) of animal dispersal) alternate with periods of immobility...
November 2016: Royal Society Open Science
Muhammad Usman Ghani, Fitsum Mesadi, Sümeyra Demir Kanık, Ali Özgür Argunşah, Anna Felicity Hobbiss, Inbal Israely, Devrim Ünay, Tolga Taşdizen, Müjdat Çetin
BACKGROUND: Neuronal morphology and function are highly coupled. In particular, dendritic spine morphology is strongly governed by the incoming neuronal activity. The first step towards understanding the structure-function relationships is to classify spine shapes into the main spine types suggested in the literature. Due to the lack of reliable automated analysis tools, classification is mostly performed manually, which is a time-intensive task and prone to subjectivity. NEW METHOD: We propose an automated method to classify dendritic spines using shape and appearance features based on challenging two-photon laser scanning microscopy (2PLSM) data...
December 17, 2016: Journal of Neuroscience Methods
Xun Wu, Yongxiang Li, Junjie Fu, Xin Li, Chunhui Li, Dengfeng Zhang, Yunsu Shi, Yanchun Song, Yu Li, Tianyu Wang
Maize foundation parents (FPs) play no-alternative roles in hybrid breeding because they were widely used in the development of new lines and hybrids. The combination of different identity-by-descent (IBD) segments and genes could account for the formation patterns of different FPs, and knowledge of these IBD regions would provide an extensive foundation for the development of new candidate FP lines in future maize breeding. In this paper, a panel of 304 elite lines derived from FPs, i.e., B73, 207, Mo17, and Huangzaosi (HZS), was collected and analyzed using 43,252 single nucleotide polymorphism (SNP) markers...
2016: PloS One
Hui Khee Looe, Dietrich Harder, Björn Poppe
The lateral dose response function is a general characteristic of the volume effect of a detector used for photon dosimetry in a water phantom. It serves as the convolution kernel transforming the true absorbed dose to water profile, which would be produced within the undisturbed water phantom, into the detector-measured signal profile. The shape of the lateral dose response function characterizes (i) the volume averaging attributable to the detector's size and (ii) the disturbance of the secondary electron field associated with the deviation of the electron density of the detector material from the surrounding water...
February 7, 2017: Physics in Medicine and Biology
M Glitzner, M F Fast, B Denis de Senneville, S Nill, U Oelfke, J J W Lagendijk, B W Raaymakers, S P M Crijns
In radiotherapy, abdominal and thoracic sites are candidates for performing motion tracking. With real-time control it is possible to adjust the multileaf collimator (MLC) position to the target position. However, positions are not perfectly matched and position errors arise from system delays and complicated response of the electromechanic MLC system. Although, it is possible to compensate parts of these errors by using predictors, residual errors remain and need to be compensated to retain target coverage...
January 7, 2017: Physics in Medicine and Biology
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