Context-aware CNNs for person head detection

Person detection is a key problem for many computer vision tasks. While face detection has reached maturity, detecting people under a full variation of camera view-points, human poses, lighting conditions and occlusions is still a difficult challenge. In this work we focus on detecting human heads in natural scenes. Starting from the recent local R-CNN object detector, we extend it with two types of contextual cues. First, we leverage person-scene relations and propose a Global CNN model trained to predict positions and scales of heads directly from the full image. Second, we explicitly model pairwise relations among objects and train a Pairwise CNN model using a structured-output surrogate loss. The Local, Global and Pairwise models are combined into a joint CNN framework. To train and test our full model, we introduce a large dataset composed of 369,846 human heads annotated in 224,740 movie frames. We evaluate our method and demonstrate improvements of person head detection against several recent baselines in three datasets. We also show improvements of the detection speed provided by our model.Comment: To appear in International Conference on Computer Vision (ICCV), 201

On the understanding of metallocene structure and dynamics via solid-state NMR.

This thesis focuses on the use of solid-state NMR spectroscopy to study the metal nuclei in various metallocenes and metallocenium cations, including, Cp*2Al+, Cp*2B+, Cp* 2BMe, Cp2Be, Cp*2Be, (C5Me4H) 2Be, CP2Mg, Cp2ZrCl2, Cp*2ZrCl 2, Cp2ZrBr2, (C5Me3H 2)2ZrBr2, (Me3Si-C5H 4)2ZrBr2, O(Me2SiC5H 4)2ZrBr2, (O(Me2Si) 2C5H3)2ZrBr2, (Me2 ClSi-C5H4)ZrCl3, and Cp2ZrMe 2. Since few studies of this nature have been reported, much of the initial material involves examining the correlation between anisotropic quadrupolar and chemical shielding interaction tensors with structural and/or dynamic features of the metallocenes. Detailed quantum mechanical calculations are also employed in order to strengthen our understanding of these correlations and the origins of anisotropic NMR interactions. Notable properties which are specific to each metallocene are investigated in detail, examples include, the very small electric field gradient (EFG) and large chemical shielding anisotropy in Cp*2Al+, sigmatropic rearrangement of the eta1-Cp* ring in Cp*2B+, and the dynamic \u27slip\u27 structure of Cp2Be. In particular, strong correlations are observed between the spherical symmetry around the metal nuclei and the magnitude of the quadrupolar interaction, as well as between Cp\u27 ring hapticity and the average nuclear magnetic shielding. Part of the reason why many metallocenes have not been studied by solid-state metal NMR is the inherently low sensitivity of the nuclei of interest, which arises from low natural abundance, low magnetogyric ratios and/or large anisotropic interactions. An attempt is made to overcome these obstacles by combining preparatory pulse sequences (double frequency sweeps (DFS), rotor-assisted population transfer (RAPT) and cross polarization (CP)) with a multiple-pulse method called the Carr-Purcell Meiboom-Gill (QCPMG) pulse sequence. These combined pulse sequences are tested on a variety of standard samples and result in signal enhancements of an order of magnitude or more depending on nuclear relaxation properties. These signal enhancement techniques make possible the solid-state NMR characterization of CP2Mg and Cp2ZrCl 2, which are important compounds in the fields of metalorganic chemical vapor deposition and olefin polymerization catalysis, respectively. The solid-state 91Zr NMR study of a series of zirconocenes is also presented, wherein an attempt is made at understanding the correlation between structure and measured EFG parameters. In particular, brominated zirconocenes which mimic the conformation of species before (Cp2ZrBr2, (C5Me3H2)2ZrBr2, (Me 3Si-C5H4)2ZrBr2) and after adsorption (O(Me2SiC5H4)2ZrBr 2, (O(Me2Si)2C5H3) 2ZrBr2) to surface materials show promise in the characterization of industrially relevant systems. The 91Zr quadrupole coupling constant is shown to be very sensitive to geometrical changes and serves as an invaluable probe for the characterization of zirconocenes.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .H86. Source: Dissertation Abstracts International, Volume: 66-11, Section: B, page: 5995. Thesis (Ph.D.)--University of Windsor (Canada), 2005

Peripheral Meson Model of Deep Inelastic Rapidity Gap Events

We show that a peripheral meson model can explain the large deep inelastic electron-proton scattering rapidity gap events observed at HERA.Comment: 12 pages, 2 figure

Tube-CNN: Modeling temporal evolution of appearance for object detection in video

Object detection in video is crucial for many applications. Compared to images, video provides additional cues which can help to disambiguate the detection problem. Our goal in this paper is to learn discriminative models for the temporal evolution of object appearance and to use such models for object detection. To model temporal evolution, we introduce space-time tubes corresponding to temporal sequences of bounding boxes. We propose two CNN architectures for generating and classifying tubes, respectively. Our tube proposal network (TPN) first generates a large number of spatio-temporal tube proposals maximizing object recall. The Tube-CNN then implements a tube-level object detector in the video. Our method improves state of the art on two large-scale datasets for object detection in video: HollywoodHeads and ImageNet VID. Tube models show particular advantages in difficult dynamic scenes.Comment: 13 pages, 8 figures, technical repor

Quantum calculations of the carrier mobility in thin films: Methodology, Matthiessen's rule and comparison with semi-classical approaches

We discuss the calculation of the carrier mobility in silicon films within the quantum Non-Equilibrium Green's Functions (NEGF) framework. We introduce a new method for the extraction of the carrier mobility that is free from contact resistance contamination, and provides accurate mobilities at a reasonable cost, with minimal needs for ensemble averages. We then introduce a new paradigm for the definition of the partial mobility $\mu_{M}$ associated with a given elastic scattering mechanism "M", taking phonons (PH) as a reference ($\mu_{M}^{-1}=\mu_{PH+M}^{-1}-\mu_{PH}^{-1}$). We argue that this definition makes better sense in a quantum transport framework as it is free from long range interference effects that can appear in purely ballistic calculations. As a matter of fact, these mobilities satisfy Matthiessen's rule for three mechanisms [surface roughness (SR), remote Coulomb scattering (RCS) and phonons] much better than the usual, single mechanism calculations. We also discuss the problems raised by the long range spatial correlations in the RCS disorder. Finally, we compare semi-classical Kubo-Greenwood (KG) and quantum NEGF calculations. We show that KG and NEGF are in reasonable agreement for phonon and RCS, yet not for SR. We point to possible deficiencies in the treatment of SR scattering in KG, opening the way for further improvements.Comment: Submitted to Journal of Applied Physic

Hand, foot and mouth disease in an immunocompetent adult due to Coxsackievirus A6

Hand, foot and mouth disease most commonly occurs in children less than 10 years old, but can occur in immunocompetent adults. We describe a 37-year-old immunocompetent man who presented with multiple painful papules and vesicles on his palms and feet together with vesicles inside the mouth. Real-time polymerase chain reaction revealed Coxsackievirus A6 in the vesicle fluid from the feet, throat swab, and rectal swab. Since the disease is highly contagious, to contain the infection it is prudent to recognise that hand, foot and mouth disease can occur in immunocompetent adults.published_or_final_versio

Development of Sustainable High-Strength Self-Consolidating Concrete Utilising Fly Ash, Shale Ash and Microsilica

With high flowability and passing ability, self-consolidating concrete (SCC) does not require compaction during casting and can improve constructability. The favourable properties of SCC have enabled its widespread adoption in many parts of the world. However, there are two major issues associated with the SCC mixes commonly used in practice. First, the cement content is usually at the high side. Since the production of cement involves calcination at high temperature and is an energy-intensive process, the high cement content imparts high embodied energy and carbon footprint to the SCC mixes. Besides, the exothermic reaction of cement hydration would cause high heat generation and early thermal cracking problem that would impair structural integrity and necessitate repair. Second, the strength is usually limited to around grade 60, which is considered as medium strength in nowadays achievable norm. With a view to develop sustainable high-strength self-consolidating concrete (HS-SCC), experimental research utilising fly ash (FA), shale ash (SA), and microsilica (MS) in the production of SCC has been conducted, as reported herein

t1-Noise Eliminated Dipolar Heteronuclear Multiple-Quantum Coherence Solid-State NMR Spectroscopy

Heteronuclear correlation (HETCOR) spectroscopy is one of the key tools in the arsenal of the solid-state NMR spectroscopist to probe spatial proximity between two different nuclei and enhance spectral resolution. Dipolar heteronuclear multiple-quantum coherence (D-HMQC) is a powerful technique that can be potentially utilized to obtain 1H detected 2D HETCOR solid-state NMR spectra of any NMR active nucleus. A long-standing problem in 1H detected D-HMQC solid-state NMR experiments is the presence of t1-noise which reduces sensitivity and impedes spectral interpretation. In this contribution, we describe novel pulse sequences, termed t1-noise eliminated (TONE) D-HMQC, that suppress t1-noise and can provide higher sensitivity and resolution than conventional D-HMQC. Monte-Carlo and numerical simulations confirm that t1-noise in conventional D-HMQC primarily occurs because random MAS frequency fluctuations cause variations in the NMR signal amplitude from scan to scan, leading to imperfect cancellation of uncorrelated signals by phase cycling. The TONE D-HMQC sequence uses 1H p-pulses to refocus the evolution of 1H CSA across each recoupling block, improving the stability of the pulse sequence to random MAS frequency fluctuations. The 1H refocusing pulses also restore the orthogonality of in-phase and anti-phase magnetization for all crystallite orientations, enabling the use of 90° flip-back or LG spin-lock trim pulses to reduce the intensity of uncorrelated signals. We demonstrate the application of these methods to acquire detected 2D 1H-35Cl and 1H-13C HETCOR spectra of histidine•HCl•H2O with reduced t1-noise. To show generality, we also apply these methods to obtain 2D 1H-17O spectra of 20%-17O fmoc-alanine and for the first time at natural abundance, 2D 1H-25Mg HETCOR spectra of magnesium hydroxide. The TONE D-HMQC sequences are also used to probe 1H-25Mg and 1H-27Al proximities in Mg-Al layered double hydroxides and confirm the even mixing of Mg and Al in these materials