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Results for "Esa Rahtu"

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Video Summarization using Deep Semantic FeaturesSep 28 2016This paper presents a video summarization technique for an Internet video to provide a quick way to overview its content. This is a challenging problem because finding important or informative parts of the original video requires to understand its content. ... More
Fine-Grained Visual Classification of AircraftJun 21 2013This paper introduces FGVC-Aircraft, a new dataset containing 10,000 images of aircraft spanning 100 aircraft models, organised in a three-level hierarchy. At the finer level, differences between models are often subtle but always visually measurable, ... More
Investigating Natural Image Pleasantness Recognition using Deep Features and Eye Tracking for Loosely Controlled Human-computer InteractionApr 07 2017This paper revisits recognition of natural image pleasantness by employing deep convolutional neural networks and affordable eye trackers. There exist several approaches to recognize image pleasantness: (1) computer vision, and (2) psychophysical signals. ... More
Learning image-to-image translation using paired and unpaired training samplesMay 08 2018Image-to-image translation is a general name for a task where an image from one domain is converted to a corresponding image in another domain, given sufficient training data. Traditionally different approaches have been proposed depending on whether ... More
Real-time Human Pose Estimation from Video with Convolutional Neural NetworksSep 23 2016In this paper, we present a method for real-time multi-person human pose estimation from video by utilizing convolutional neural networks. Our method is aimed for use case specific applications, where good accuracy is essential and variation of the background ... More
ICface: Interpretable and Controllable Face Reenactment Using GANsApr 03 2019This paper presents a generic face animator that is able to control the pose and expressions of a given face image. The animation is driven by human interpretable control signals consisting of head pose angles and the Action Unit (AU) values. The control ... More
Multimodal Machine Learning-based Knee Osteoarthritis Progression Prediction from Plain Radiographs and Clinical DataApr 12 2019May 06 2019Knee osteoarthritis (OA) is the most common musculoskeletal disease without a cure, and current treatment options are limited to symptomatic relief. Prediction of OA progression is a very challenging and timely issue, and it could, if resolved, accelerate ... More
Learning Joint Representations of Videos and Sentences with Web Image SearchAug 08 2016Our objective is video retrieval based on natural language queries. In addition, we consider the analogous problem of retrieving sentences or generating descriptions given an input video. Recent work has addressed the problem by embedding visual and textual ... More
PIVO: Probabilistic Inertial-Visual Odometry for Occlusion-Robust NavigationAug 02 2017Jan 23 2018This paper presents a novel method for visual-inertial odometry. The method is based on an information fusion framework employing low-cost IMU sensors and the monocular camera in a standard smartphone. We formulate a sequential inference scheme, where ... More
Inertial Odometry on Handheld SmartphonesMar 01 2017Jun 07 2018Building a complete inertial navigation system using the limited quality data provided by current smartphones has been regarded challenging, if not impossible. This paper shows that by careful crafting and accounting for the weak information in the sensor ... More
Rethinking the Evaluation of Video SummariesMar 27 2019Video summarization is a technique to create a short skim of the original video while preserving the main stories/content. There exists a substantial interest in automatizing this process due to the rapid growth of the available material. The recent progress ... More
Image-based Localization using Hourglass NetworksMar 23 2017Aug 24 2017In this paper, we propose an encoder-decoder convolutional neural network (CNN) architecture for estimating camera pose (orientation and location) from a single RGB-image. The architecture has a hourglass shape consisting of a chain of convolution and ... More
Exploiting inter-image similarity and ensemble of extreme learners for fixation prediction using deep featuresOct 20 2016This paper presents a novel fixation prediction and saliency modeling framework based on inter-image similarities and ensemble of Extreme Learning Machines (ELM). The proposed framework is inspired by two observations, 1) the contextual information of ... More
ADVIO: An authentic dataset for visual-inertial odometryJul 25 2018The lack of realistic and open benchmarking datasets for pedestrian visual-inertial odometry has made it hard to pinpoint differences in published methods. Existing datasets either lack a full six degree-of-freedom ground-truth or are limited to small ... More
Predicting Novel Views Using Generative Adversarial Query NetworkApr 10 2019The problem of predicting a novel view of the scene using an arbitrary number of observations is a challenging problem for computers as well as for humans. This paper introduces the Generative Adversarial Query Network (GAQN), a general learning framework ... More
Automatic Knee Osteoarthritis Diagnosis from Plain Radiographs: A Deep Learning-Based ApproachOct 29 2017Knee osteoarthritis (OA) is the most common musculoskeletal disorder. OA diagnosis is currently conducted by assessing symptoms and evaluating plain radiographs, but this process suffers from subjectivity. In this study, we present a new transparent computer-aided ... More
A novel method for automatic localization of joint area on knee plain radiographsJan 31 2017Apr 05 2017Osteoarthritis (OA) is a common musculoskeletal condition typically diagnosed from radiographic assessment after clinical examination. However, a visual evaluation made by a practitioner suffers from subjectivity and is highly dependent on the experience. ... More
Relative Camera Pose Estimation Using Convolutional Neural NetworksFeb 05 2017Jul 28 2017This paper presents a convolutional neural network based approach for estimating the relative pose between two cameras. The proposed network takes RGB images from both cameras as input and directly produces the relative rotation and translation as output. ... More
DAVE: A Deep Audio-Visual Embedding for Dynamic Saliency PredictionMay 25 2019This paper presents a conceptually simple and effective Deep Audio-Visual Eembedding for dynamic saliency prediction dubbed ``DAVE". Several behavioral studies have shown a strong relation between auditory and visual cues for guiding gaze during scene ... More
Digging Deeper into Egocentric Gaze PredictionApr 12 2019This paper digs deeper into factors that influence egocentric gaze. Instead of training deep models for this purpose in a blind manner, we propose to inspect factors that contribute to gaze guidance during daily tasks. Bottom-up saliency and optical flow ... More
Nonparametric Simultaneous Sparse Recovery: an Application to Source LocalizationFeb 09 2015Jun 10 2015We consider multichannel sparse recovery problem where the objective is to find good recovery of jointly sparse unknown signal vectors from the given multiple measurement vectors which are different linear combinations of the same known elementary vectors. ... More
What Did Fisher Mean by An Estimate?Jul 22 2008Fisher's Method of Maximum Likelihood is shown to be a procedure for the construction of likelihood intervals or regions, instead of a procedure of point estimation. Based on Fisher's articles and books it is justified that by estimation Fisher meant ... More
Direction of arrival estimation using robust complex LassoMay 12 2016The Lasso (Least Absolute Shrinkage and Selection Operator) has been a popular technique for simultaneous linear regression estimation and variable selection. In this paper, we propose a new novel approach for robust Lasso that follows the spirit of M-estimation. ... More
Multichannel sparse recovery of complex-valued signals using Huber's criterionApr 16 2015In this paper, we generalize Huber's criterion to multichannel sparse recovery problem of complex-valued measurements where the objective is to find good recovery of jointly sparse unknown signal vectors from the given multiple measurement vectors which ... More
The SU(N) Wilson Loop Average in 2 DimensionsJun 18 1993Feb 04 1994We solve explicitly a closed, linear loop equation for the SU(2) Wilson loop average on a two-dimensional plane and generalize the solution to the case of the SU(N) Wilson loop average with an arbitrary closed contour. Furthermore, the flat space solution ... More
Summarization of User-Generated Sports Video by Using Deep Action Recognition FeaturesSep 25 2017Apr 13 2018Automatically generating a summary of sports video poses the challenge of detecting interesting moments, or highlights, of a game. Traditional sports video summarization methods leverage editing conventions of broadcast sports video that facilitate the ... More
DGC-Net: Dense Geometric Correspondence NetworkOct 19 2018Oct 22 2018This paper addresses the challenge of dense pixel correspondence estimation between two images. This problem is closely related to optical flow estimation task where ConvNets (CNNs) have recently achieved significant progress. While optical flow methods ... More
Moments and oscillations of exponential sums related to cusp formsFeb 12 2014Jan 04 2016We consider large values of long linear exponential sums involving Fourier coefficients of holomorphic cusp forms. The sums we consider involve rational linear twists $e(nh/k)$ with sufficiently small denominators. We prove both pointwise upper bounds ... More
Criticality of Large Delay Tolerant Networks via Directed Continuum Percolation in Space-TimeAug 02 2012We study delay tolerant networking (DTN) and in particular, its capacity to store, carry and forward messages so that the messages eventually reach their final destinations. We approach this broad question in the framework of percolation theory. To this ... More
Extended Ewald Summation TechniqueSep 15 2014We present a technique to efficiently compute long-range interactions in systems with periodic boundary conditions. We extend the well-known Ewald method by using a linear combination of screening Gaussian charge distributions instead of only one as in ... More
Optimal shrinkage covariance matrix estimation under random sampling from elliptical distributionsAug 30 2018This paper considers the problem of estimating a high-dimensional (HD) covariance matrix when the sample size is smaller, or not much larger, than the dimensionality of the data, which could potentially be very large. We develop a regularized sample covariance ... More
Porosities of Mandelbrot PercolationJun 28 2016We study porosities in the Mandelbrot percolation process. We show that, almost surely at almost all points with respect to the natural measure, the mean porosities of the set and the natural measure exist and are equal to each other for all parameter ... More
Regularized $M$-estimators of scatter matrixMay 11 2014Jun 09 2014In this paper, a general class of regularized $M$-estimators of scatter matrix are proposed which are suitable also for low or insufficient sample support (small $n$ and large $p$) problems. The considered class constitutes a natural generalization of ... More
Non-Scattering Energies and Transmission Eigenvalues in $\mathbb H^n$Sep 12 2018Sep 16 2018We consider non-scattering energies and transmission eigenvalues of compactly supported potentials in the hyperbolic spaces $\mathbb H^n$. We prove that in $\mathbb H^2$ a corner bounded by two hyperbolic lines intersecting at an angle smaller than $180^\circ$ ... More
Non-Scattering Energies and Transmission Eigenvalues in $\mathbb H^n$Sep 12 2018May 08 2019We consider non-scattering energies and transmission eigenvalues of compactly supported potentials in the hyperbolic spaces $\mathbb H^n$. We prove that in $\mathbb H^2$ a corner bounded by two hyperbolic lines intersecting at an angle smaller than $180^\circ$ ... More
On Sums Involving Fourier Coefficients of Maass Forms for $\mathrm{SL}(3,\mathbb Z)$Sep 28 2016We derive a truncated Voronoi identity for rationally additively twisted sums of Fourier coefficients of Maass forms for $\mathrm{SL}(3,\mathbb Z)$, and as an application obtain a pointwise estimate and a second moment estimate for the sums in question. ... More
Exponential Sums Related to Maass FormsSep 25 2014Apr 07 2015We estimate short exponential sums weighted by the Fourier coefficients of a Maass form. This requires working out a certain transformation formula for non-linear exponential sums, which is of independent interest. We also discuss how the results depend ... More
Multimodal Machine Learning-based Knee Osteoarthritis Progression Prediction from Plain Radiographs and Clinical DataApr 12 2019Knee osteoarthritis (OA) is the most common musculoskeletal disease without a cure, and current treatment options are limited to symptomatic relief. Prediction of OA progression is a very challenging and timely issue, and it could, if resolved, accelerate ... More
Minimizing Slowdown in Heterogeneous Size-Aware Dispatching Systems (full version)Mar 22 2012We consider a system of parallel queues where tasks are assigned (dispatched) to one of the available servers upon arrival. The dispatching decision is based on the full state information, i.e., on the sizes of the new and existing jobs. We are interested ... More
Porosities and dimensions of measuresMar 17 1999We introduce a concept of porosity for measures and study relations between dimensions and porosities for two classes of measures: measures on $R^n$ which satisfy the doubling condition and strongly porous measures on $R$.
Exact Coulomb cutoff technique for supercell calculations in two dimensionsMar 04 2009May 14 2009We present a reciprocal space technique for the calculation of the Coulomb integral in two dimensions in systems with reduced periodicity, i.e., finite systems, or systems that are periodic only in one dimension. The technique consists in cutting off ... More
Optimal control of photoelectron emission by realistic waveformsJul 11 2016Nov 04 2016Recent experimental techniques in multicolor waveform synthesis allow the temporal shaping of strong femtosecond laser pulses with applications in the control of quantum mechanical processes in atoms, molecules, and nanostructures. Prediction of the shapes ... More
Efficient Algorithms for Scheduling Moldable TasksSep 27 2016Jul 28 2018Moldable tasks allow schedulers to determine the number of processors assigned to a task, enabling efficient use of large-scale parallel processing systems. A generic assumption is that every task is monotonic, i.e., its workload increases but its execution ... More
Hausdorff dimension and non-degenerate families of projectionsMar 23 2012We study parametrized families of orthogonal projections for which the dimension of the parameter space is strictly less than that of the Grassmann manifold. We answer the natural question of how much the Hausdorff dimension may decrease by verifying ... More
Shape identification in inverse medium scattering problems with a single far-field patternJul 28 2015Consider time-harmonic acoustic scattering from a bounded penetrable obstacle $D\subset \mathbb R^N$ embedded in a homogeneous background medium. The index of refraction characterizing the material inside $D$ is supposed to be H\"older continuous near ... More
Discreteness of Transmission Eigenvalues for Higher-Order Main Terms and PerturbationsDec 17 2015In this paper we extend Sylvester's approach via upper triangular compact operators to establish the discreteness of transmission eigenvalues for higher-order main terms and higher-order perturbations. The coefficients of the perturbations must be sufficiently ... More
A Cost-Effective Resource Provisioning Framework using Online Learning in IaaS CloudsJul 18 2016Jul 22 2016Cloud vendors often offer three types of instances: reserved, on-demand and spot instances; a premier challenge for all users is to determine the proportion of various instances so as to minimize the cost of completing all jobs while satisfying their ... More
Robust iterative hard thresholding for compressed sensingMay 07 2014Compressed sensing (CS) or sparse signal reconstruction (SSR) is a signal processing technique that exploits the fact that acquired data can have a sparse representation in some basis. One popular technique to reconstruct or approximate the unknown sparse ... More
Modelling Graph Errors: Towards Robust Graph Signal ProcessingMar 20 2019The first step for any graph signal processing (GSP) procedure is to learn the graph signal representation, i.e., to capture the dependence structure of the data into an adjacency matrix. Indeed, the adjacency matrix is typically not known a priori and ... More
Strictly convex corners scatterApr 09 2014Apr 25 2014We prove the absence of non-scattering energies for potentials in the plane having a corner of angle smaller than $\pi$. This extends the earlier result of Bl{\aa}sten, P\"aiv\"arinta and Sylvester who considered rectangular corners. In three dimensions, ... More
Optimal control of photoelectron emission by realistic waveformsJul 11 2016Jul 13 2016Recent experimental techniques in multicolor waveform synthesis allow the temporal shaping of strong femtosecond laser pulses with applications in the control of quantum mechanical processes in atoms, molecules, and nanostructures. Prediction of the shapes ... More
Towards Designing Cost-Optimal Policies to Utilize IaaS Clouds under Online LearningJul 18 2016Jul 21 2018Many businesses possess a small infrastructure that they can use for their computing tasks, but also often buy extra computing resources from clouds. Cloud vendors such as Amazon EC2 offer two types of purchase options: on-demand and spot instances. As ... More
Robust, scalable and fast bootstrap method for analyzing large scale dataApr 09 2015Apr 12 2015In this paper we address the problem of performing statistical inference for large scale data sets i.e., Big Data. The volume and dimensionality of the data may be so high that it cannot be processed or stored in a single computing node. We propose a ... More
Generalized Lie Algebroids - Examples by Distinguished Lie Algebroids with Applications to Optimal ControlAug 20 2018We will prove that the generalized Lie algebroid is a distinguished example by Lie algebroid. The generality of it with respect to the Lie algebroid is similar with the generality of the pull-back vector bundle with respect to the vector bundle. Next, ... More
Hausdorff dimension of limsup sets of rectangles in the Heisenberg groupApr 27 2018Feb 02 2019The almost sure value of the Hausdorff dimension of limsup sets generated by randomly distributed rectangles in the Heisenberg group is computed in terms of directed singular value functions.
Two Hops or More: On Hop-Limited Search in Opportunistic NetworksNov 16 2015While there is a drastic shift from host-centric networking to content-centric networking, how to locate and retrieve the relevant content efficiently, especially in a mobile network, is still an open question. Mobile devices host increasing volume of ... More
Hausdorff dimension of limsup sets of random rectangles in products of regular spacesMay 07 2017Nov 30 2017The almost sure Hausdorff dimension of the limsup set of randomly distributed rectangles in a product of Ahlfors regular metric spaces is computed in terms of the singular value function of the rectangles.
Dimensions of random covering sets in Riemann manifoldsAug 31 2015Let ${\pmb M}$, ${\pmb N}$ and ${\pmb K}$ be $d$-dimensional Riemann manifolds. Assume that ${\bf A}:=(A_n)_{n\in{\Bbb N}}$ is a sequence of Lebesgue measurable subsets of ${\pmb M}$ satisfying a necessary density condition and ${\bf x}:=(x_n)_{n\in {\Bbb ... More
A Novel Subclass of Analytic Functions Specified by a Family of Fractional Derivatives in the Complex DomainNov 05 2015In this paper, by making use of a certain family of fractional derivative operators in the complex domain, we introduce and investigate a new subclass $\mathcal{P}_{\tau,\mu}(k,\delta,\gamma)$ of analytic and univalent functions in the open unit disk ... More
Besicovitch-Federer projection theorem and geodesic flows on Riemann surfacesApr 18 2011Dec 12 2012We extend the Besicovitch-Federer projection theorem to transversal families of mappings. As an application we show that on a certain class of Riemann surfaces with constant negative curvature and with boundary, there exist natural 2-dimensional measures ... More
Fractal Dynamics in Chaotic Quantum TransportOct 14 2012Jul 28 2013Despite several experiments on chaotic quantum transport in two-dimensional systems such as semiconductor quantum dots, corresponding quantum simulations within a real-space model have been out of reach so far. Here we carry out quantum transport calculations ... More
On the Fractal Dimension of the Visible UniverseJan 03 2003Estimates of the fractal dimension $D$ of the set of galaxies in the universe, based on ever improving data sets, tend to settle on $D\approx 2$. This result raised a raging debate due to its glaring contradiction with astrophysical models that expect ... More
Asymptotically sharp dimension estimates for $k$-porous setsJan 30 2017In $\mathbb{R}^n$, we establish an asymptotically sharp upper bound for the upper Minkowski dimension of $k$-porous sets having holes of certain size near every point in $k$ orthogonal directions at all small scales. This bound tends to $n-k$ as $k$-porosity ... More
Fundamental gaps of quantum dots on the cheapFeb 19 2019We show that the fundamental gaps of quantum dots can be accurately estimated at the computational effort of a standard ground-state calculation supplemented with a non self-consistent step of negligible cost, all performed within density-functional theory ... More
Hausdorff dimension of affine random covering sets in torusJul 16 2012May 07 2013We calculate the almost sure Hausdorff dimension of the random covering set $\limsup_{n\to\infty}(g_n + \xi_n)$ in $d$-dimensional torus $\mathbb T^d$, where the sets $g_n\subset\mathbb T^d$ are parallelepipeds, or more generally, linear images of a set ... More
Simultaneous penalized M-estimation of covariance matrices using geodesically convex optimizationAug 29 2016A common assumption when sampling $p$-dimensional observations from $K$ distinct group is the equality of the covariance matrices. In this paper, we propose two penalized $M$-estimation approaches for the estimation of the covariance or scatter matrices ... More
Resonances and $Ω$-results for Exponential Sums Related to Maass Forms for $\mathrm{SL}(n,\mathbb Z)$May 28 2014Aug 06 2014We obtain resonances for short exponential sums involving Fourier coefficients of Maass forms for $\mathrm{SL}(n,\mathbb Z)$. This involves deriving asymptotics for the integrals appearing in the $\mathrm{GL}(n)$ Voronoi summation formula. As an application, ... More
Random affine code tree fractals: Hausdorff and affinity dimensions and pressureOct 09 2015We prove that for random affine code tree fractals the affinity dimension is almost surely equal to the unique zero of the pressure function. As a consequence, we show that the Hausdorff, packing and box counting dimensions of such systems are equal to ... More
Random affine code tree fractals and Falconer-Sloan conditionApr 09 2014Sep 16 2014We calculate the almost sure dimension for a general class of random affine code tree fractals in $\mathbb R^d$. The result is based on a probabilistic version of the Falconer-Sloan condition $C(s)$ introduced in \cite{FS}. We verify that, in general, ... More
On asymptotics of ICA estimators and their performance indicesDec 17 2012Independent component analysis (ICA) has become a popular multivariate analysis and signal processing technique with diverse applications. This paper is targeted at discussing theoretical large sample properties of ICA unmixing matrix functionals. We ... More
Density-functional investigation of molecular graphene: CO on Cu(111)Sep 01 2014Man-made artificial graphene has attracted significant attention in the past few years due to the possibilities to construct designer Dirac fermions with unexpected topological properties and applications in nanoelectronics. Here we use a first-principles ... More
Singularity of projections of 2-dimensional measures invariant under the geodesic flowApr 14 2011We show that on any compact Riemann surface with variable negative curvature there exists a measure which is invariant and ergodic under the geodesic flow and whose projection to the base manifold is 2-dimensional and singular with respect to the 2-dimensional ... More
Deep Learning Fundus Image Analysis for Diabetic Retinopathy and Macular Edema GradingApr 16 2019Diabetes is a globally prevalent disease that can cause visible microvascular complications such as diabetic retinopathy and macular edema in the human eye retina, the images of which are today used for manual disease screening. This labor-intensive task ... More
Shape recovery from sparse tomographic X-ray dataMay 04 2016A two-dimensional tomographic problem is studied. The target is assumed to be a homogeneous object bounded by a smooth curve. A Non Uniform Rational Basis Splines (NURBS) curve is used as computational representation of the boundary. This approach conveniently ... More
Strong quantum scarring by local impuritiesNov 13 2015Mar 04 2016We discover and characterize strong quantum scars, or eigenstates resembling classical periodic orbits, in two-dimensional quantum wells perturbed by local impurities. These scars are not explained by ordinary scar theory, which would require the existence ... More
Dimensions of random affine code tree fractalsFeb 01 2012We calculate the almost sure Hausdorff dimension for a general class of random affine planar code tree fractals. The set of probability measures describing the randomness includes natural measures in random $V$-variable and homogeneous Markov constructions. ... More
Multi-resolution parameter choice method for total variation regularized tomographyJul 09 2014Aug 11 2015A computational method is introduced for choosing the regularization parameter for total variation (TV) regularization. The approach is based on computing reconstructions at a few different resolutions and various values of regularization parameter. The ... More
Scaling in the correlation energies of two-dimensional artificial atomsSep 06 2012Oct 22 2013We find an unexpected scaling in the correlation energy of artificial atoms, i.e., harmonically confined two-dimensional quantum dots. The scaling relation is found through extensive numerical examinations including Hartree-Fock, variational quantum Monte ... More
Toward an all-round semi-local potential for the electronic exchangeOct 29 2010We test local and semi-local density functionals for the electronic exchange for a variety of systems including atoms, molecules, and atomic chains. In particular, we focus on a recent universal extension of the Becke-Johnson exchange potential [E. R\"as\"anen, ... More
Bistatic full-wave radar tomography detects deep interior voids, cracks and boulders in a rubble-pile asteroid modelFeb 01 2019In this paper, we investigate full-wave computed radar tomography (CRT) using a rubble-pile asteroid model in which a realistic shape (Itokawa) is coupled with a synthetic material composition and structure model. The aim is to show that sparse bistatic ... More
Hitting probabilities of random covering sets in tori and metric spacesOct 22 2015May 22 2016We provide sharp lower and upper bounds for the Hausdorff dimension of the intersection of a typical random covering set with a fixed analytic set both in Ahlfors regular metric spaces and in the $d$-dimensional torus. In metric spaces, we consider covering ... More
Rellich Type Theorems for Unbounded DomainsJan 18 2014We give several generalizations of Rellich's classical uniqueness theorem to unbounded domains. We give a natural half-space generalization for super-exponentially decaying inhomogeneities using real variable techniques. We also prove under super-exponential ... More
Transmission Eigenvalues for a Class of Non-Compactly Supported PotentialsMay 28 2013Jan 18 2014Let $\Omega\subseteq\mathbb R^n$ be a non-empty open set for which the Sobolev embedding $H_0^2(\Omega)\longrightarrow L^2(\Omega)$ is compact, and let $V\in L^\infty(\Omega)$ be a potential taking only positive real values and satisfying the asymptotics ... More
Packing dimension and Ahlfors regularity of porous sets in metric spacesJan 30 2017Let $X$ be a metric measure space with an $s$-regular measure $\mu$. We prove that if $A\subset X$ is $\varrho$-porous, then $\dim_{\mathrm{p}}(A)\le s-c\varrho^s$ where $\dim_{\mathrm{p}}$ is the packing dimension and $c$ is a positive constant which ... More
Distributed Coordinated Transmission with Forward-Backward Training for 5G Radio AccessFeb 12 2018Sep 22 2018Coordinated multipoint (CoMP) transmission and reception have been considered in cellular networks for enabling larger coverage, improved rates, and interference mitigation. To harness the gains of coordinated beamforming, fast information exchange over ... More
Detecting solar g-modes with ASTRODFeb 12 2008We present an up-to-date estimate for the prospect of using the Astrodynamical Space Test of Relativity using Optical Devices (ASTROD) for an unambiguous detection of solar g modes (f < 400 micro Hertz) through their gravitational signature. There are ... More
DISCUS - The Deep Interior Scanning CubeSat mission to a rubble pile near-Earth asteroidMay 04 2018We have performed an initial stage conceptual design study for the Deep Interior Scanning CubeSat (DISCUS), a tandem 6U CubeSat carrying a bistatic radar as main payload. DISCUS will be operated either as an independent mission or accompanying a larger ... More
Far-Field Inversion for the Deep Interior Scanning CubeSatSep 13 2017Mar 29 2018This study aims at advancing mathematical and computational techniques for reconstructing the interior structure of a near earth asteroid (NEA) via Computed Radar Tomography (CRT). We introduce a far-field model for full-wave CRT and validate it numerically ... More
Bill2d - a software package for classical two-dimensional Hamiltonian systemsJun 23 2015Dec 28 2015We present Bill2d, a modern and efficient C++ package for classical simulations of two-dimensional Hamiltonian systems. Bill2d can be used for various billiard and diffusion problems with one or more charged particles with interactions, different external ... More
Solar wind charge exchange in cometary atmospheres. I. Charge-changing and ionization cross sections for He and H particles in H$_2$OFeb 13 2019Solar wind charge-changing reactions are of paramount importance to the physico-chemistry of the atmosphere of a comet, mass-loading the solar wind through an effective conversion of fast light solar wind ions into slow heavy cometary ions. To understand ... More
The albedo-color diversity of transneptunian objectsJun 05 2014Sep 07 2014We analyze albedo data obtained using the Herschel Space Observatory that reveal the existence of two distinct types of surface among midsized transneptunian objects. A color-albedo diagram shows two large clusters of objects, one redder and higher albedo ... More
Catalogue of 55-80 MeV solar proton events extending through solar cycles 23 and 24Jul 03 2017We present a new catalogue of solar energetic particle events near the Earth, covering solar cycle 23 and the majority of solar cycle 24 (1996-2016), based on the 55-80 MeV proton intensity data gathered by the SOHO/ERNE experiment. In addition to ERNE ... More
Solar wind charge exchange in cometary atmospheres III. Results from the Rosetta mission to comet 67P/Churyumov-GerasimenkoFeb 12 2019Solar wind charge-changing reactions are of paramount importance to the physico-chemistry of the atmosphere of a comet. The ESA/Rosetta mission to comet 67P/Churyumov-Gerasimenko (67P) provides a unique opportunity to study charge-changing processes in ... More
Time-Dependent Density-Functional Theory of Strong-Field Ionization of Atoms under Soft X-RaysAug 26 2014We demonstrate the capabilities of time-dependent density functional theory (TDDFT) for strong-field, short wavelength (soft X-ray) physics, as compared to a formalism based on rate equations. We find that TDDFT provides a very good description of the ... More
"TNOs are Cool": A survey of the trans-Neptunian region -- VII. Size and surface characteristics of (90377) Sedna and 2010 EK139Apr 04 2012We present estimates of the basic physical properties (size and albedo) of (90377) Sedna, a prominent member of the detached trans-Neptunian object population and the recently discovered scattered disk object 2010 EK139, based on the recent observations ... More
Czochralski Silicon as a Detector Material for S-LHC Tracker VolumesAug 24 2010With an expected ten-fold increase in luminosity in S-LHC, the radiation environment in the tracker volumes will be considerably harsher for silicon-based detectors than the already harsh LHC environment. Since 2006, a group of CMS institutes, using a ... More
Tomographic X-ray data of a walnutFeb 11 2015This is the documentation of the tomographic X-ray data of a walnut made available at http://www.fips.fi/dataset.php . The data can be freely used for scientific purposes with appropriate references to the data and to this document in arXiv. The data ... More
Tomographic inversion of gravity gradient field for a small solar system body: Mathematical methodology, resolution, noise and measurement configurationMar 13 2019In this paper, we investigate gravity gradient field inversion of spacecraft-performed measurements in numerical experiments, in which the asteroid model is based on the shape of the asteroid Itokawa. We base our models on the recent observations and ... More