bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Dynamics Near a Homoclinic Network to a Bifocus: Switching and Horseshoes
Authors: Ibáñez Santiago , Rodrigues Alexandre
Published: October 2015

We study a homoclinic network associated to a nonresonant hyperbolic bifocus. It is proved that on combining rotation with a nondegeneracy condition concerning the intersection of the two-dimensional invariant manifolds of the equilibrium, switching behavior is created: close to the network, there are trajectories that visit the neighborhood of the bifocus following connections in any prescribed order. We discuss the existence of suspended horseshoes which accumulate on the network and the relation between these horseshoes and the switching behavior.
A Frequency Domain Approach for Controlling Fast-Scale Instabilities in Switching Power Converters
Authors: Rodriguez E. , Alarcón E. , Iu H. H. C. , El Aroudi A.
Published: October 2015

This paper deals with controllers of fast-scale instabilities in DC–DC switching power converters from a frequency domain standpoint with the aim of understanding their working principle and hence simplifying their design. Some approaches for controlling fast-scale instabilities and their limitations are revisited. Considering the frequency domain transfer function of already existing controllers, a simple and extended notch filter centered at half of the switching frequency is proposed to avoid these instabilities. However, a switching converter under this controller may still exhibit the undesired slow-scale instability. Accordingly, the paper explores an alternative approach based on amplifying the harmonic at the switching frequency. Numerical simulations show that the new proposed controller can concurrently improve both fast-scale and slow-scale stability margins. The results from the different controllers are contrasted in terms of stability boundaries, indicating that the last one presents a wider stability range.
Bifurcation Diagrams and Quotient Topological Spaces Under the Action of the Affine Group of a Family of Planar Quadratic Vector Fields
Authors: Cerba Diaconescu Oxana , Schlomiuk Dana , Vulpe Nicolae
Published: October 2015

In this article, we consider the class [Formula: see text] of all real quadratic differential systems [Formula: see text], [Formula: see text] with gcd (p, q) = 1, having invariant lines of total multiplicity four and two complex and one real infinite singularities. We first construct compactified canonical forms for the class [Formula: see text] so as to include limit points in the 12-dimensional parameter space of this class. We next construct the bifurcation diagrams for these compactified canonical forms. These diagrams contain many repetitions of phase portraits and we show that these are due to many symmetries under the group action. To retain the essence of the dynamics we finally construct the quotient spaces under the action of the group G = Aff(2, ℝ) × ℝ* of affine transformations and time homotheties and we place the phase portraits in these quotient spaces. The final diagrams retain only the necessary information to capture the dynamics under the motion in the parameter space as well as under this group action. We also present here necessary and sufficient conditions for an affine line to be invariant of multiplicity k for a quadratic system.
Stable Running with Asymmetric Legs: A Bifurcation Approach
Authors: Merker Andreas , Kaiser Dieter , Seyfarth Andre , Hermann Martin
Published: October 2015

The spring-mass model is a frequently used gait template to describe human and animal locomotion. In this study, we transform the spring-mass model for running into a boundary value problem and use it for the computation of bifurcation points. We show that the analysis of the region of stable solutions can be reduced to the calculation of its boundaries. Using the new bifurcation approach, we investigate the influence of asymmetric leg parameters on the stability of running. Like previously found in walking, leg asymmetry does not necessarily restrict the range of stable running and may even provide benefits for system dynamics.
Directional Control of Bifurcation into Targeted Trajectory
Authors: Jaćimović Vladimir , Konatar Nikola
Published: October 2015

The field of bifurcation control includes several classes of problems that are actively studied with various motivations and from different points of view. The different statements of the problem are articulated by defining various objectives of applying control to the system, depending on the motivation and the specific problem. In this paper, we propose the objective of bifurcation control that is based on one of the main features of bifurcation phenomena: bifurcation generates possibilities for different scenarios to occur. We show how to find the right directions to control the system in order to ensure the realization of a favorable scenario. Our method is based on a bifurcation theorem for an abstract problem with constraints (inequalities). This theorem is further applied to controlled dynamical systems and two reasonably simple bifurcation control problems are analyzed in order to illustrate our objective and method.
MATHEMATICAL MODELING OF INTRA-VENOUS GLUCOSE TOLERANCE TEST MODEL WITH TWO DISCRETE DELAYS
Authors: PITCHAIMANI M. , KRISHNAPRIYA P. , MONICA C.
Published: October 2015

A mathematical model for Intra-Venous Glucose Tolerance Test (IVGTT) with explicit glucose–insulin interaction is presented as a system of delay differential equation with discrete time delays and its important mathematical features are analyzed. This model includes the positivity and boundedness of the solution. An unique equilibrium point is found and its local stability is investigated. Using the Lyapunov functional approach, we show the global stability of the unique equilibrium point. The length of delay that preserves the stability is estimated. Sensitivity analysis is performed on a delay differential equation model for IVGTT that suggests the parameter value has a major impact on the model dynamics. Numerical calculations are performed to support and elaborate the analytical findings.
The (2, 3)-generation of the special unitary groups of dimension 6
Authors: Pellegrini M. A. , Prandelli M. , Tamburini Bellani M. C.
Published: October 2015

In this paper we give explicit [Formula: see text]-generators of the finite unitary groups [Formula: see text], for all [Formula: see text]. They fit into a uniform sequence of likely [Formula: see text]-generators for all [Formula: see text].
The X (X = F, Cl, I) effect on the photoassociation of H+X→HX
Authors: Gao Wei , Wang Bin-Bin , Han Yong-Chang , Cong Shu-Lin
Published: October 2015

This work explores the vibrational state-selective photoassociation (PA) in the ground state of the HX (X = F, Cl, I) molecule by solving the time-dependent Schrödinger equation. For the three systems, the vibrational level of [Formula: see text] is set to be the target state and the PA probability of the target state is calculated and compared by considering different initial collision momentums. It is found that the PA probabilities are in accordance with Franck–Condon overlap integral for the HI and HCl systems, but it is not the case for the HF system. Moreover, for the HF system, it is shown that the PA probability of the target state is largest and the multiphoton transition is more likely to occur.
HPMV: Human protein mutation viewer — relating sequence mutations to protein sequence architecture and function changes
Authors: Sherman Westley Arthur , Kuchibhatla Durga Bhavani , Limviphuvadh Vachiranee , Maurer-Stroh Sebastian , Eisenhaber Birgit , Eisenhaber Frank
Published: October 2015

Next-generation sequencing advances are rapidly expanding the number of human mutations to be analyzed for causative roles in genetic disorders. Our Human Protein Mutation Viewer (HPMV) is intended to explore the biomolecular mechanistic significance of non-synonymous human mutations in protein-coding genomic regions. The tool helps to assess whether protein mutations affect the occurrence of sequence-architectural features (globular domains, targeting signals, post-translational modification sites, etc.). As input, HPMV accepts protein mutations — as UniProt accessions with mutations (e.g. HGVS nomenclature), genome coordinates, or FASTA sequences. As output, HPMV provides an interactive cartoon showing the mutations in relation to elements of the sequence architecture. A large variety of protein sequence architectural features were selected for their particular relevance to mutation interpretation. Clicking a sequence feature in the cartoon expands a tree view of additional information including multiple sequence alignments of conserved domains and a simple 3D viewer mapping the mutation to known PDB structures, if available. The cartoon is also correlated with a multiple sequence alignment of similar sequences from other organisms. In cases where a mutation is likely to have a straightforward interpretation (e.g. a point mutation disrupting a well-understood targeting signal), this interpretation is suggested. The interactive cartoon can be downloaded as standalone viewer in Java jar format to be saved and viewed later with only a standard Java runtime environment. The HPMV website is: http://hpmv.bii.a-star.edu.sg/ .
A method to predict different mechanisms for blood–brain barrier permeability of CNS activity compounds in Chinese herbs using support vector machine
Authors: Jiang Ludi , Chen Jiahua , He Yusu , Zhang Yanling , Li Gongyu
Published: October 2015

The blood–brain barrier (BBB), a highly selective barrier between central nervous system (CNS) and the blood stream, restricts and regulates the penetration of compounds from the blood into the brain. Drugs that affect the CNS interact with the BBB prior to their target site, so the prediction research on BBB permeability is a fundamental and significant research direction in neuropharmacology. In this study, we combed through the available data and then with the help of support vector machine (SVM), we established an experiment process for discovering potential CNS compounds and investigating the mechanisms of BBB permeability of them to advance the research in this field four types of prediction models, referring to CNS activity, BBB permeability, passive diffusion and efflux transport, were obtained in the experiment process. The first two models were used to discover compounds which may have CNS activity and also cross the BBB at the same time; the latter two were used to elucidate the mechanism of BBB permeability of those compounds. Three optimization parameter methods, Grid Search, Genetic Algorithm (GA), and Particle Swarm Optimization (PSO), were used to optimize the SVM models. Then, four optimal models were selected with excellent evaluation indexes (the accuracy, sensitivity and specificity of each model were all above 85%). Furthermore, discrimination models were utilized to study the BBB properties of the known CNS activity compounds in Chinese herbs and this may guide the CNS drug development. With the relatively systematic and quick approach, the application rationality of traditional Chinese medicines for treating nervous system disease in the clinical practice will be improved.
On generalized semiderivations in 3-prime near-rings
Authors: Boua A. , Oukhtite L. , Raji A.
Published: October 2015

There is a large body of evidence showing that the existence of a suitably-constrained derivation on a 3-prime near-ring forces the near-ring to be a commutative ring. The purpose of this paper is to study generalized semiderivations which satisfy certain identities on 3-prime near-ring and generalize some results due to [H. E. Bell and G. Mason, On derivations in near-rings, North-Holland Math. Stud. 137 (1987) 31–35; H. E. Bell, On prime near-rings with generalized derivation, Int. J. Math. Math. Sci. 2008 (2008), Article ID: 490316, 5[Formula: see text]pp; A. Boua and L. Oukhtite, Some conditions under which near-rings are rings, Southeast Asian Bull. Math. 37 (2013) 325–331]. Moreover, an example is given to prove that the necessity of the 3-primeness hypothesis imposed on the various theorems cannot be marginalized.
Solvable groups with restrictions on Sylow subgroups of the Fitting subgroup
Authors: Trofimuk Alexander
Published: October 2015

In this paper, we study solvable groups in which [Formula: see text] is at most 2. In particular, we investigated groups of odd order and [Formula: see text]-free groups with this property. Exact estimations of the derived length and nilpotent length of such groups are obtained.
GLAD
Authors: Yu Rose , He Xinran , Liu Yan
Published: October 2015

Traditional anomaly detection on social media mostly focuses on individual point anomalies while anomalous phenomena usually occur in groups. Therefore, it is valuable to study the collective behavior of individuals and detect group anomalies. Existing group anomaly detection approaches rely on the assumption that the groups are known, which can hardly be true in real world social media applications. In this article, we take a generative approach by proposing a hierarchical Bayes model:
Group Latent Anomaly Detection
(GLAD) model. GLAD takes both pairwise and point-wise data as input, automatically infers the groups and detects group anomalies simultaneously. To account for the dynamic properties of the social media data, we further generalize GLAD to its dynamic extension d-GLAD. We conduct extensive experiments to evaluate our models on both synthetic and real world datasets. The empirical results demonstrate that our approach is effective and robust in discovering latent groups and detecting group anomalies.
A chebyshev semi-iterative approach for accelerating projective and position-based dynamics
Authors: Wang Huamin
Published: October 2015

In this paper, we study the use of the Chebyshev semi-iterative approach in projective and position-based dynamics. Although projective dynamics is fundamentally nonlinear, its convergence behavior is similar to that of an iterative method solving a linear system. Because of that, we can estimate the "spectral radius" and use it in the Chebyshev approach to accelerate the convergence by at least one order of magnitude, when the global step is handled by the direct solver, the Jacobi solver, or even the Gauss-Seidel solver. Our experiment shows that the combination of the Chebyshev approach and the direct solver runs fastest on CPU, while the combination of the Chebyshev approach and the Jacobi solver outperforms any other combination on GPU, as it is highly compatible with parallel computing. Our experiment further shows position-based dynamics can be accelerated by the Chebyshev approach as well, although the effect is less obvious for tetrahedral meshes. The whole approach is simple, fast, effective, GPU-friendly, and has a small memory cost.
Level-set-based partitioning and packing optimization of a printable model
Authors: Yao Miaojun , Chen Zhili , Luo Linjie , Wang Rui , Wang Huamin
Published: October 2015

As the 3D printing technology starts to revolutionize our daily life and the manufacturing industries, a critical problem is about to e-merge: how can we find an automatic way to divide a 3D model into multiple printable pieces, so as to save the space, to reduce the printing time, or to make a large model printable by small printers. In this paper, we present a systematic study on the partitioning and packing of 3D models under the multi-phase level set framework. We first construct analysis tools to evaluate the qualities of a partitioning using six metrics: stress load, surface details, interface area, packed size, printability, and assembling. Based on this analysis, we then formulate level set methods to improve the qualities of the partitioning according to the metrics. These methods are integrated into an automatic system, which repetitively and locally optimizes the partitioning. Given the optimized partitioning result, we further provide a container structure modeling algorithm to facilitate the packing process of the printed pieces. Our experiment shows that the system can generate quality partitioning of various 3D models for space saving and fast production purposes.
Rolling guidance normal filter for geometric processing
Authors: Wang Peng-Shuai , Fu Xiao-Ming , Liu Yang , Tong Xin , Liu Shi-Lin , Guo Baining
Published: October 2015

3D geometric features constitute rich details of polygonal meshes. Their analysis and editing can lead to vivid appearance of shapes and better understanding of the underlying geometry for shape processing and analysis. Traditional mesh smoothing techniques mainly focus on noise filtering and they cannot distinguish different scales of features well, even mixing them up. We present an efficient method to process different scale geometric features based on a novel rolling-guidance normal filter. Given a 3D mesh, our method iteratively applies a joint bilateral filter to face normals at a specified scale, which empirically smooths small-scale geometric features while preserving large-scale features. Our method recovers the mesh from the filtered face normals by a modified Poisson-based gradient deformation that yields better surface quality than existing methods. We demonstrate the effectiveness and superiority of our method on a series of geometry processing tasks, including geometry texture removal and enhancement, coating transfer, mesh segmentation and level-of-detail meshing.
Deep points consolidation
Authors: Wu Shihao , Huang Hui , Gong Minglun , Zwicker Matthias , Cohen-Or Daniel
Published: October 2015

In this paper, we present a consolidation method that is based on a new representation of 3D point sets. The key idea is to augment each surface point into a
deep point
by associating it with an inner point that resides on the meso-skeleton, which consists of a mixture of skeletal curves and sheets. The deep points representation is a result of a joint optimization applied to both ends of the deep points. The optimization objective is to fairly distribute the end points across the surface and the meso-skeleton, such that the deep point orientations agree with the surface normals. The optimization converges where the inner points form a coherent meso-skeleton, and the surface points are consolidated with the missing regions completed. The strength of this new representation stems from the fact that it is comprised of both local and non-local geometric information. We demonstrate the advantages of the deep points consolidation technique by employing it to consolidate and complete noisy point-sampled geometry with large missing parts.
On optimal, minimal BRDF sampling for reflectance acquisition
Authors: Nielsen Jannik Boll , Jensen Henrik Wann , Ramamoorthi Ravi
Published: October 2015

The bidirectional reflectance distribution function (BRDF) is critical for rendering, and accurate material representation requires data-driven reflectance models. However, isotropic BRDFs are 3D functions, and measuring the reflectance of a flat sample can require a million incident and outgoing direction pairs, making the use of measured BRDFs impractical. In this paper, we address the problem of reconstructing a measured BRDF from a limited number of samples. We present a novel mapping of the BRDF space, allowing for extraction of descriptive principal components from measured databases, such as the MERL BRDF database. We optimize for the best sampling directions, and explicitly provide the optimal set of incident and outgoing directions in the Rusinkiewicz parameterization for
n
= {1, 2, 5, 10, 20} samples. Based on the principal components, we describe a method for accurately reconstructing BRDF data from these limited sets of samples. We validate our results on the MERL BRDF database, including favorable comparisons to previous sets of industry-standard sampling directions, as well as with BRDF measurements of new flat material samples acquired with a gantry system. As an extension, we also demonstrate how this method can be used to find optimal sampling directions when imaging a sphere of a homogeneous material; in this case, only two images are often adequate for high accuracy.
Subspace dynamic simulation using rotation-strain coordinates
Authors: Pan Zherong , Bao Hujun , Huang Jin
Published: October 2015

In this paper, we propose a full featured and efficient subspace simulation method in the rotation-strain (RS) space for elastic objects. Sharply different from previous methods using the rotation-strain space, except for the ability to handle non-linear elastic materials and external forces, our method correctly formulates the kinetic energy, centrifugal and Coriolis forces which significantly reduces the dynamic artifacts. We show many techniques used in the Euclidean space methods, such as modal derivatives, polynomial and cubature approximation, can be adapted to our RS simulator. Carefully designed experiments show that the equation of motion in RS space has less non-linearity than its Euclidean counterpart, and as a consequence, our method has great advantages of lower dimension and computational complexity than state-of-the-art methods in the Euclidean space.
Nested cages
Authors: Sacht Leonardo , Vouga Etienne , Jacobson Alec
Published: October 2015

Many tasks in geometry processing and physical simulation benefit from multiresolution hierarchies. One important characteristic across a variety of applications is that coarser layers strictly
encage
finer layers, nesting one another. Existing techniques such as surface mesh decimation, voxelization, or contouring distance level sets do not provide sufficient control over the
quality
of the output surfaces while maintaining strict nesting. We propose a solution that enables use of application-specific decimation and quality metrics. The method constructs each next-coarsest level of the hierarchy, using a sequence of decimation, flow, and contact-aware optimization steps. From coarse to fine, each layer then fully encages the next while retaining a snug fit. The method is applicable to a wide variety of shapes of complex geometry and topology. We demonstrate the effectiveness of our nested cages not only for multigrid solvers, but also for conservative collision detection, domain discretization for elastic simulation, and cage-based geometric modeling.
Magic decorator
Authors: Chen Kang , Xu Kun , Yu Yizhou , Wang Tian-Yi , Hu Shi-Min
Published: October 2015

Assigning textures and materials within 3D scenes is a tedious and labor-intensive task. In this paper, we present
Magic Decorator
, a system that automatically generates material suggestions for 3D indoor scenes. To achieve this goal, we introduce
local material rules
, which describe typical material patterns for a small group of objects or parts, and
global aesthetic rules
, which account for the harmony among the entire set of colors in a specific scene. Both rules are obtained from collections of indoor scene images. We cast the problem of material suggestion as a combinatorial optimization considering both local material and global aesthetic rules. We have tested our system on various complex indoor scenes. A user study indicates that our system can automatically and efficiently produce a series of visually plausible material suggestions which are comparable to those produced by artists.
CrossLink
Authors: Hueting Moos , Ovsjanikov Maks , Mitra Niloy J.
Published: October 2015

Collections of images and 3D models hide in them many interesting aspects of our surroundings. Significant efforts have been devoted to organize and explore such data repositories. Most such efforts, however, process the two data modalities separately, and do not take full advantage of the complementary information that exist in different domains, which can help to solve difficult problems in one by exploiting the structure in the other. Beyond the obvious difference in data representations, a key difficulty in such joint analysis lies in the significant variability in the structure and inherent properties of the 2D and 3D data collections, which hinders cross-domain analysis and exploration. We introduce CrossLink, a system for joint image-3D model processing that uses the complementary strengths of each data modality to facilitate analysis and exploration. We first show how our system significantly improves the quality of text-based 3D model search by using side information coming from an image database. We then demonstrate how to consistently align the filtered 3D model collections, and then use them to re-sort image collections based on pose and shape attributes. We evaluate our framework both quantitatively and qualitatively on 20 object categories of 2D image and 3D model collections, and quantitatively demonstrate how a wide variety of tasks in each data modality can strongly benefit from the complementary information present in the other, paving the way to a richer 2D and 3D processing toolbox.
Orbifold Tutte embeddings
Authors: Aigerman Noam , Lipman Yaron
Published: October 2015

Injective parameterizations of surface meshes are vital for many applications in Computer Graphics, Geometry Processing and related fields. Tutte's embedding, and its generalization to convex combination maps, are among the most popular approaches for computing parameterizations of surface meshes into the plane, as they guarantee injectivity, and their computation only requires solving a sparse linear system. However, they are only applicable to disk-type and toric surface meshes.

In this paper we suggest a generalization of Tutte's embedding to other surface topologies, and in particular the common, yet untreated case, of sphere-type surfaces. The basic idea is to enforce certain boundary conditions on the parameterization so as to achieve a Euclidean orbifold structure. The orbifold-Tutte embedding is a seamless, globally bijective parameterization that, similarly to the classic Tutte embedding, only requires solving a sparse linear system for its computation.

In case the cotangent weights are used, the orbifold-Tutte embedding globally minimizes the Dirichlet energy and is shown to approximate conformal and four-point quasiconformal mappings. As far as we are aware, this is the first fully-linear method that produces bijective approximations to conformal mappings.

Aside from parameterizations, the orbifold-Tutte embedding can be used to generate bijective inter-surface mappings with three or four landmarks and symmetric patterns on sphere-type surfaces.
A system for rapid, automatic shader level-of-detail
Authors: He Yong , Foley Theresa , Tatarchuk Natalya , Fatahalian Kayvon
Published: October 2015

Level-of-detail (LOD) rendering is a key optimization used by modern video game engines to achieve high-quality rendering with fast performance. These LOD systems require simplified shaders, but generating simplified shaders remains largely a manual optimization task for game developers. Prior efforts to automate this process have taken hours to generate simplified shader candidates, making them impractical for use in modern shader authoring workflows for complex scenes. We present an end-to-end system for automatically generating a LOD policy for an input shader. The system operates on shaders used in both forward and deferred rendering pipelines, requires no additional semantic information beyond input shader source code, and in only seconds to minutes generates LOD policies (consisting of simplified shader, the desired LOD distance set, and transition generation) with performance and quality characteristics comparable to custom hand-authored solutions. Our design contributes new shader simplification transforms such as approximate common subexpression elimination and movement of GPU logic to parameter bind-time processing on the CPU, and it uses a greedy search algorithm that employs extensive caching and upfront collection of input shader statistics to rapidly identify simplified shaders with desirable performance-quality trade-offs.
Transform recipes for efficient cloud photo enhancement
Authors: Gharbi Michaël , Shih YiChang , Chaurasia Gaurav , Ragan-Kelley Jonathan , Paris Sylvain , Durand Frédo
Published: October 2015

Cloud image processing is often proposed as a solution to the limited computing power and battery life of mobile devices: it allows complex algorithms to run on powerful servers with virtually unlimited energy supply. Unfortunately, this overlooks the time and energy cost of uploading the input and downloading the output images. When transfer overhead is accounted for, processing images on a remote server becomes less attractive and many applications do not benefit from cloud offloading. We aim to change this in the case of image enhancements that preserve the overall content of an image. Our key insight is that, in this case, the server can compute and transmit a description of thetransformationfrom input to output, which we call atransform recipe.At equivalent quality, our recipes are much more compact than JPEG images: this reduces the client's download. Furthermore, recipes can be computed from highly compressed inputs which significantly reduces the data uploaded to the server. The client reconstructs a high-fidelity approximation of the output by applying the recipe to its local high-quality input. We demonstrate our results on 168 images and 10 image processing applications, showing that our recipes form a compact representation for a diverse set of image filters. With an equivalent transmission budget, they provide higher-quality results than JPEG-compressed input/output images, with a gain of the order of 10 dB in many cases. We demonstrate the utility of recipes on a mobile phone by profiling the energy consumption and latency for both local and cloud computation: a transform recipe-based pipeline runs 2--4x faster and uses 2--7x less energy than local or naive cloud computation.
Interactive surface design with interlocking elements
Authors: Skouras Mélina , Coros Stelian , Grinspun Eitan , Thomaszewski Bernhard
Published: October 2015

We present an interactive tool for designing physical surfaces made from flexible interlocking quadrilateral elements of a single size and shape. With the element shape fixed, the design task becomes one of finding a discrete structure---i.e., element connectivity and binary orientations---that leads to a desired geometry. In order to address this challenging problem of combinatorial geometry, we propose a forward modeling tool that allows the user to interactively explore the space of feasible designs. Paralleling principles from conventional modeling software, our approach leverages a library of base shapes that can be instantiated, combined, and extended using two fundamental operations: merging and extrusion. In order to assist the user in building the designs, we furthermore propose a method to automatically generate assembly instructions. We demonstrate the versatility of our method by creating a diverse set of digital and physical examples that can serve as personalized lamps or decorative items.
Data-driven fluid simulations using regression forests
Authors: Ladický L'ubor , Jeong SoHyeon , Solenthaler Barbara , Pollefeys Marc , Gross Markus
Published: October 2015

Traditional fluid simulations require large computational resources even for an average sized scene with the main bottleneck being a very small time step size, required to guarantee the stability of the solution. Despite a large progress in parallel computing and efficient algorithms for pressure computation in the recent years, realtime fluid simulations have been possible only under very restricted conditions. In this paper we propose a novel machine learning based approach, that formulates physics-based fluid simulation as a regression problem, estimating the acceleration of every particle for each frame. We designed a feature vector, directly modelling individual forces and constraints from the Navier-Stokes equations, giving the method strong generalization properties to reliably predict positions and velocities of particles in a large time step setting on yet unseen test videos. We used a regression forest to approximate the behaviour of particles observed in the large training set of simulations obtained using a traditional solver. Our GPU implementation led to a speed-up of one to three orders of magnitude compared to the state-of-the-art position-based fluid solver and runs in real-time for systems with up to 2 million particles.
Break Ames room illusion
Authors: Shi Jianping , Tao Xin , Xu Li , Jia Jiaya
Published: October 2015

Photos compress 3D visual data to 2D. However, it is still possible to infer depth information even without sophisticated object learning. We propose a solution based on small-scale defocus blur inherent in optical lens and tackle the estimation problem by proposing a non-parametric matching scheme for natural images. It incorporates a matching prior with our newly constructed edgelet dataset using a non-local scheme, and includes semantic depth order cues for physically based inference. Several applications are enabled on natural images, including geometry based rendering and editing.
Pharmacogenomics of estrogens on changes in carotid artery intima-medial thickness and coronary arterial calcification: Kronos Early Estrogen Prevention Study
Authors: Miller Virginia M. , Jenkins Gregory D. , Biernacka Joanna M. , Heit John A. , Huggins Gordon S. , Hodis Howard N. , Budoff Matthew J. , Lobo Rogerio A. , Taylor Hugh S. , Manson JoAnn E. , Black Dennis M. , Naftolin Frederick , Harman S. Mitchell , de Andrade Mariza
Published: October 2015

Prior to the initiation of menopausal hormone treatment (MHT), genetic variations in the innate immunity pathway were found to be associated with carotid artery intima-medial thickness (CIMT) and coronary arterial calcification (CAC) in women ( n = 606) enrolled in the Kronos Early Estrogen Prevention Study (KEEPS). Whether MHT might affect these associations is unknown. The association of treatment outcomes with variation in the same 764 candidate genes was evaluated in the same KEEPS participants 4 yr after randomization to either oral conjugated equine estrogens (0.45 mg/day), transdermal 17β-estradiol (50 μg/day), each with progesterone (200 mg/day) for 12 days each month, or placebo pills and patch. Twenty SNPs within the innate immunity pathway most related with CIMT after 4 yr were not among those associated with CIMT prior to MHT. In 403 women who completed the study in their assigned treatment group, single nucleotide polymorphisms (SNPs) within the innate immunity pathway were found to alter the treatment effect on 4 yr change in CIMT (i.e., significant interaction between treatment and genetic variation in the innate immunity pathway; P < 0.001). No SNPs by treatment effects were observed with changes of CAC >5 Agatston units after 4 yr. Results of this study suggest that hormonal status may interact with genetic variants to influence cardiovascular phenotypes, specifically, the pharmacogenomic effects within the innate immunity pathway for CIMT.
Telomere dynamics during aging in polygenic left ventricular hypertrophy
Authors: Marques Francine Z. , Booth Scott A. , Prestes Priscilla R. , Curl Claire L. , Delbridge Lea M. D. , Lewandowski Paul , Harrap Stephen B. , Charchar Fadi J.
Published: October 2015

Short telomeres are associated with increased risk of cardiovascular disease. Here we studied cardiomyocyte telomere length at key ages during the ontogeny of cardiac hypertrophy and failure in the hypertrophic heart rat (HHR) and compared these with the normal heart rat (NHR) control strain. Key ages corresponded with the pathophysiological sequence beginning with fewer cardiomyocytes (2 days), leading to left ventricular hypertrophy (LVH) (13 wk) and subsequently progression to heart failure (38 wk). We measured telomere length, tissue activity of telomerase, mRNA levels of telomerase reverse transcriptase ( Tert) and telomerase RNA component ( Terc), and expression of the telomeric regulator microRNA miR-34a. Cardiac telomere length was longer in the HHR compared with the control strain at 2 days and 38 wk, but shorter at 13 wk. Neonatal HHR had higher cardiac telomerase activity and expression of Tert and miR-34a. Telomerase activity was not different at 13 or 38 wk. Tert mRNA and Terc RNA were overexpressed at 38 wk, while miR-34a was overexpressed at 13 wk but downregulated at 38 wk. Circulating leukocytes were strongly correlated with cardiac telomere length in the HHR only. The longer neonatal telomeres in HHR are likely to reflect fewer fetal and early postnatal cardiomyocyte cell divisions and explain the reduced total cardiomyocyte complement that predisposes to later hypertrophy and failure. Although shorter telomeres were a feature of cardiac hypertrophy at 13 wk, they were not present at the progression to heart failure at 38 wk.
A Multibeam Dual-Band Orthogonal Linearly Polarized Antenna Array for Satellite Communication on the Move
Authors: Liu Yi , Yang Hu , Mao Shaojun , Zhu Jiang
Published: October 2015

The design and simulation of a 10 × 8 multibeam dual-band orthogonal linearly polarized antenna array operating at Ku-band are presented for transmit-receive applications. By using patches with different coupling methods as elements, both perpendicular polarization in 12.25–12.75 GHz band and horizontal polarization in 14.0–14.5 GHz band are realized in a shared antenna aperture. A microstrip Rotman lens is employed as the beamforming network with 7 input ports, which can generate a corresponding number of beams to cover −30°–30° with 5 dB beamwidth along one dimension. This type of multibeam orthogonal linearly polarized planar antenna is a good candidate for satellite communication (SatCom).
Downlink and Uplink Cooperative Transmission for Primary Secrecy Based Cognitive Radio Sensor Networks
Authors: Wang Dawei , Ren Pinyi , Du Qinghe , Sun Li , Wang Yichen
Published: October 2015

Aiming at allocating more licensed spectrum to wireless sensor nodes (SNs) under the constraint of the information security requirement of the primary system, in this paper, we propose a cooperative relaying and jamming secure transmission (CRJS) scheme in which SNs will relay primary message and jam primary eavesdrop concurrently with SN’s downlink and uplink information transmission in cognitive radio sensor networks (CRSNs). In our proposed CRJS scheme, SNs take advantages of physical layer secure technologies to protect the primary transmission and acquire some interference-free licensed spectrum as a reward. In addition, both decode-and-forward (DF) and amplify-and-forward (AF) relaying protocols are investigated in our proposed CRJS scheme. Our object is to maximize the transmission rate of SNs by optimal allocating of the relaying power, jamming power, and downlink and uplink transmit power under the target secure transmission rate requirement of the primary system. Moreover, two suboptimal algorithms are proposed to deal with these optimization problems. Furthermore, we analyze the transmission rate of SNs and allocate the relaying power, jamming power, and downlink and uplink transmit power for the asymptotic scenarios. Simulation results demonstrate the performance superiority of our developed strategy over conventional jamming scheme in terms of the transmission rate of WSN.
FPGA Implementation of Optimal 3D‐Integer DCT Structure for Video Compression
Authors: Jacob J. Augustin , Kumar N. Senthil
Published: October 2015

A novel optimal structure for implementing 3D‐integer discrete cosine transform (DCT) is presented by analyzing various integer approximation methods. The integer set with reduced mean squared error (MSE) and high coding efficiency are considered for implementation in FPGA. The proposed method proves that the least resources are utilized for the integer set that has shorter bit values. Optimal 3D‐integer DCT structure is determined by analyzing the MSE, power dissipation, coding efficiency, and hardware complexity of different integer sets. The experimental results reveal that direct method of computing the 3D‐integer DCT using the integer set [10, 9, 6, 2, 3, 1, 1] performs better when compared to other integer sets in terms of resource utilization and power dissipation.
The Existence of Exponential Attractor for Discrete Ginzburg-Landau Equation
Authors: Du Guangyin , Zhu Zeqi , Zhao Caidi
Published: October 2015

This paper studies the following discrete systems of the complex Ginzburg-Landau equation:iu˙m-(α-iε)(2um-um+1-um-1)+iκum+βum2σum=gm,  m∈Z. Under some conditions on the parametersα, ε, κ, β, andσ, we prove the existence of exponential attractor for the semigroup associated with these discrete systems.
The Randomized American Option as a Classical Solution to the Penalized Problem
Authors: Leduc Guillaume
Published: October 2015

We connect the exercisability randomized American option to the penalty method by showing that the randomized American option valueuis the uniqueclassicalsolution to the Cauchy problem corresponding to thecanonicalpenalty problem for American options. We also establish a uniform bound forAu, whereAis the infinitesimal generator of a geometric Brownian motion.
Technique for Outdoor Test on Concentrating Photovoltaic Cells
Authors: Sansoni Paola , Fontani Daniela , Francini Franco , Jafrancesco David , Pierucci Giacomo , De Lucia Maurizio
Published: October 2015

Outdoor experimentation of solar cells is essential to maximize their performance and to assess utilization requirements and limits. More generally tests with direct exposure to the sun are useful to understand the behavior of components and new materials for solar applications in real working conditions. Insolation and ambient factors are uncontrollable but can be monitored to know the environmental situation of the solar exposure experiment. A parallel characterization of the photocells can be performed in laboratory under controllable and reproducible conditions. A methodology to execute solar exposure tests is proposed and practically applied on photovoltaic cells for a solar cogeneration system. The cells are measured with concentrated solar light obtained utilizing a large Fresnel lens mounted on a sun tracker. Outdoor measurements monitor the effects of the exposure of two multijunction photovoltaic cells to focused sunlight. The main result is the continuous acquisition of theV-I(voltage-current) curve for the cells in different conditions of solar concentration and temperature of exercise to assess their behavior. The research investigates electrical power extracted, efficiency, temperatures reached, and possible damages of the photovoltaic cell.
Short-Term Memory Impairment and Left Dorsolateral Prefrontal Cortex Dysfunction in the Orthostatic Position: A Single Case Study of Sinking Skin Flap Syndrome
Authors: Sebastianelli Luca , Stoll Verena , Versace Viviana , Martignago Sara , Obletter Stephan , Lavoriero Marco , Malfertheiner Kathrin , Gisser Gertraud , Saltuari Leopold
Published: October 2015

We describe the case of a patient who underwent craniectomy for hemorrhage of the left parietal lobe. Three weeks later, orthostatic memory impairment was detected as initial symptom of sinking skin flap syndrome (SSFS). This deficit was examined by neuropsychological testing and associated with a posture-dependent increase in the delta/alpha ratio at the F3 electrode, an electroencephalographic (EEG) index related to brain hypoperfusion. This EEG spectral alteration was detected in a brain region that includes the left dorsolateral prefrontal cortex, an area known to be involved in memory processing; therefore we hypothesize that SSFS induced reversible hypoperfusion of this otherwise undamaged cortical region. Neither of these findings was present after cranioplasty. This case suggests that SSFS may induce neuropsychological deficits potentially influencing outcome in the postacute phase and is further evidence supporting the clinical benefits of early cranioplasty.
An Economic User-Centric WiFi Offloading Algorithm for Heterogeneous Network
Authors: Kou Jinfeng , Xiao Yang , Wang Dong
Published: October 2015

An economic user-centric WiFi offloading algorithm is proposed to satisfy the major concerns of wireless users, who wish to have better network performance with even less network expense. Thus in this paper both system throughput and network expense are considered, and the goal of the proposed offloading algorithm is to obtain an optimal offloading ratio, which can both maximize the system throughput and minimize the network expense. Firstly, a practical system model is set up on the basis of a typical scenario of heterogeneous network. In this model, the average throughput of both cellular network and WiFi network is analyzed carefully. Then an economic user-centric WiFi offloading algorithm is proposed with an evaluation function to evaluate the system, and the optimal offloading ratio can be obtained by minimizing the evaluation function. At last, numerical results represent a direct calculating process of the optimal offloading ratio. These results in return validate the efficiency of the proposed offloading algorithm as well.
Interim Clinical Outcomes in Nanocomposite Bone Material Repairing Large Proximal Femoral Defect of Fibrous Dysplasia
Authors: Lang Yun , Yu Ze-ping , Xiong Yan , Tu Chong-qi , Ren Cheng , Zhang Bin , Yang Hong-sheng , Yuan Fang , Li Hong , Yan Yong-gang , Duan Hong
Published: October 2015

Background and Objectives. To evaluate the clinical effectiveness and safety of using nanocomposite bone material in the repair of large proximal femoral defects that are due to fibrous dysplasia. Method. Thirty‐one patients were analyzed retrospectively, including 13 males and 18 females, and the mean age was 30.9 years (13–59). The median follow‐up period was 50 months (30–78) and the masses of artificial bone transplants were in the range of 15~40 g (average of 23.4 g). Functional and radiographic outcomes were evaluated. Results. All wounds healed to grade A. There were no infections, nonspecific inflammatory reactions, rejection reactions, or fractures. One case had fat liquefaction and healed after dressing. All patients had no recurrence until the last follow‐up. At the last follow‐up, the mean Musculoskeletal Tumor Society’s (MSTS) 93 score was 28.42 ± 1.31, the mean Harris hip score was 84.23 ± 8.97, and mean radiopaque density ratio was 0.78 ± 0.09. Radiologic analysis indicated that nanocomposite bone material had been completely incorporated with the host bone within a year. Conclusions. This study indicated that the nanocomposite bone material had biological safety and good biocompatibility. In conclusion, the nanocomposite bone material is an ideal artificial bone substitute and worthy of promotion in the field of orthopedics.
Investigation of In Situ Boron‐Doping in SiGe Source/Drain Layer Growth for PMOS Devices
Authors: Zhong Min , Chen Shou Mian , Zhang David Wei
Published: October 2015

Embedded SiGe (eSiGe) source/drain (S/D) was studied to enhance PMOS performance. Detailed investigations concerning the effect of GeH4 and B2H6 gas flow rate on the resultant Boron‐doping of the SiGe layer (on a 40 nm patterned wafer) were carried out. Various SiGeB epitaxial growth experiments were realized under systematically varying experimental conditions. Key structural and chemical characteristics of the SiGeB layers were investigated using Secondary Ion Mass Spectroscopy (SIMS), nanobeam diffraction mode (NBD), and Transmission Electron Microscopy (TEM) itself. Furthermore, Ion/Ioff performances of 40 nm PMOS transistors are also measured by the Parametric Test Systems for the semiconductor industry. The results indicate that the ratio between GeH4 and B2H6 gas flow rates influences not only the Ge and Boron content of the SiGeB layer, but also the PMOS channel strain and the morphology of the eSiGe S/D regions which directly affect PMOS performance. In addition, the mechanism of Boron‐doping during SiGe layer growth on the pattern wafer is briefly discussed. The results and discussion presented within this paper are expected to contribute to the optimization of eSiGe stressor, aimed for advanced CMOS devices.