4,394 research outputs found

    Unsupervised Segmentation of Action Segments in Egocentric Videos using Gaze

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    Unsupervised segmentation of action segments in egocentric videos is a desirable feature in tasks such as activity recognition and content-based video retrieval. Reducing the search space into a finite set of action segments facilitates a faster and less noisy matching. However, there exist a substantial gap in machine understanding of natural temporal cuts during a continuous human activity. This work reports on a novel gaze-based approach for segmenting action segments in videos captured using an egocentric camera. Gaze is used to locate the region-of-interest inside a frame. By tracking two simple motion-based parameters inside successive regions-of-interest, we discover a finite set of temporal cuts. We present several results using combinations (of the two parameters) on a dataset, i.e., BRISGAZE-ACTIONS. The dataset contains egocentric videos depicting several daily-living activities. The quality of the temporal cuts is further improved by implementing two entropy measures.Comment: To appear in 2017 IEEE International Conference On Signal and Image Processing Application

    2-index chiral gauge theories

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    We undertake a systematic study of the 44-dimensional SU(N)SU(N) 22-index chiral gauge theories and investigate their faithful global symmetries and dynamics. These are a finite set of theories with fermions in the 22-index symmetric and anti-symmetric representations, with no fundamentals, and they do not admit a large-NN limit. We employ a combination of perturbative and nonperturbative methods, enabling us to constrain their infrared (IR) phases. Specifically, we leverage the 't Hooft anomalies associated with continuous and discrete groups to eliminate a few scenarios. In some cases, the anomalies rule out the possibility of fermion composites. In other cases, the interplay between the continuous and discrete anomalies leads to multiple higher-order condensates, which inevitably form to match the anomalies. Further, we pinpoint the most probable symmetry-breaking patterns by searching for condensates that match the full set of anomalies resulting in the smallest number of IR degrees of freedom. Higher-loop β\beta-function analysis suggests that a few theories may flow to a conformal fixed point.Comment: 40 pages + appendice

    2-index chiral gauge theories

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    We undertake a systematic study of the 4-dimensional SU(N) 2-index chiral gauge theories and investigate their faithful global symmetries and dynamics. These are a finite set of theories with fermions in the 2-index symmetric and anti-symmetric representations, with no fundamentals, and they do not admit a large-N limit. We employ a combination of perturbative and nonperturbative methods, enabling us to constrain their infrared (IR) phases. Specifically, we leverage the ’t Hooft anomalies associated with continuous and discrete groups to eliminate a few scenarios. In some cases, the anomalies rule out the possibility of fermion composites. In other cases, the interplay between the continuous and discrete anomalies leads to multiple higher-order condensates, which inevitably form to match the anomalies. Further, we pinpoint the most probable symmetry-breaking patterns by searching for condensates that match the full set of anomalies resulting in the smallest number of IR degrees of freedom. Higher-loop β-function analysis suggests that a few theories may flow to a conformal fixed point

    Noninvertible symmetries and anomalies from gauging 11-form electric centers

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    We devise a general method for obtaining 00-form noninvertible discrete chiral symmetries in 44-dimensional SU(N)/ZpSU(N)/\mathbb Z_p and SU(N)×U(1)/ZpSU(N)\times U(1)/\mathbb Z_p gauge theories with matter in arbitrary representations, where Zp\mathbb Z_p is a subgroup of the electric 11-form center symmetry. Our approach involves placing the theory on a three-torus and utilizing the Hamiltonian formalism to construct noninvertible operators by introducing twists compatible with the gauging of Zp\mathbb Z_p. These theories exhibit electric 11-form and magnetic 11-form global symmetries, and their generators play a crucial role in constructing the corresponding Hilbert space. The noninvertible operators are demonstrated to project onto specific Hilbert space sectors characterized by particular magnetic fluxes. Furthermore, when subjected to twists by the electric 11-form global symmetry, these surviving sectors reveal an anomaly between the noninvertible and the 11-form symmetries. We argue that an anomaly implies that certain sectors, characterized by the eigenvalues of the electric symmetry generators, exhibit multi-fold degeneracies. When we couple these theories to axions, infrared axionic noninvertible operators inherit the ultraviolet structure of the theory, including the projective nature of the operators and their anomalies. We discuss various examples of vector and chiral gauge theories that showcase the versatility of our approach.Comment: 42 page

    Spin injection in Silicon at zero magnetic field

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    In this letter, we show efficient electrical spin injection into a SiGe based \textit{p-i-n} light emitting diode from the remanent state of a perpendicularly magnetized ferromagnetic contact. Electron spin injection is carried out through an alumina tunnel barrier from a Co/Pt thin film exhibiting a strong out-of-plane anisotropy. The electrons spin polarization is then analysed through the circular polarization of emitted light. All the light polarization measurements are performed without an external applied magnetic field \textit{i.e.} in remanent magnetic states. The light polarization as a function of the magnetic field closely traces the out-of-plane magnetization of the Co/Pt injector. We could achieve a circular polarization degree of the emitted light of 3 % at 5 K. Moreover this light polarization remains almost constant at least up to 200 K.Comment: accepted in AP

    Superlight small bipolarons from realistic long-range Coulomb and Fr\"ohlich interactions

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    We report analytical and numerical results on the two-particle states of the polaronic t-Jp model derived recently with realistic Coulomb and electron-phonon (Frohlich) interactions in doped polar insulators. Eigenstates and eigenvalues are calculated for two different geometries. Our results show that the ground state is a bipolaronic singlet, made up of two polarons. The bipolaron size increases with increasing ratio of the polaron hopping integral t to the exchange interaction Jp but remains small compared to the system size in the whole range 0<t/Jp<1. Furthermore, the model exhibits a phase transition to a superconducting state with a critical temperature well in excess of 100K. In the range t/Jp<1, there are distinct charge and spin gaps opening in the density of states, specific heat, and magnetic susceptibility well above Tc.Comment: Calculation section and discussion of gap have been updated. Revised calculations now enhance the predicted T_c in our model to over 200 K at large hoppin

    THE PERCEPTION OF ESTATE MANAGEMENT STUDENTS OF COVENANT UNIVERSITY TO THE COURSE VALUATION: COMPREHENSIBLE OR NOT?

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    Valuation is very important to the real estate profession. It is a veritable tool for decision making in property transaction and require that opinion of values given for an interest in landed property by practitioners are reliable and consistent. However, the study of valuation by university students appears to have generated bias over the years. The failure rate in valuation compared to other courses seems to be higher. The aim of this paper is to examine the Perception of Estate Management students to the study of valuation. Estate management students of covenant university students from 200 to 500 levels (being the levels offering valuation as a subject) were adopted as population sample for the study. Structured questionnaires were analyzed and the simple descriptive statistics were used for the study. The outcome of the study shows that some of the students are not fully aware of the course- Estate Management but were compelled to study it and as such are not enjoying some of the subjects particularly valuation while some are aware but find valuation particularly difficult and the others are of the opinion that valuation is very interesting. It recommends that more orientation should be given to students about the different discipline and the courses / subjects that make up the study before embarking on such a study at the universit

    The Effect of Luteolin on Human Glioblastoma

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    Glioblastoma multiforme (GBM) is widely recognized as the most common and lethal of the malignant gliomas. Few effective therapeutic treatments are available as five-year survival rates of diagnosed individuals are less than five percent. Luteolin, a common flavonoid found in a variety of fruits and vegetables, has demonstrated significant promise in combating cancers of the breast, colon, liver, lung, and bone. In this study, we investigated the effects of luteolin on glioblastoma multiforme cell lines U-251, U-87, and U-1242. Cell viability was assessed using cell count with trypan blue exclusion and MTT assays. Results revealed that luteolin reduces GBM cell viability and cell proliferation in a time and concentration-dependent manner. Western Blot analysis indicated that luteolin decreased AKT, ERK, and MAPK phosphorylation following treatment with EGF. Additionally, luteolin promoted apoptosis in GBM cells by inducing PARP and caspase-3 cleavage, and decreasing levels of the anti-apoptotic protein BCL-XL. Our results indicate that luteolin exhibits a biological effect and may be used as a therapeutic agent for glioblastoma multiforme

    Endothelin-3 like immunoreactivity in plasma of patients with cirrhosis of the liver

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    A highly specific and sensitive radioimmunoassay (RIA) has been established for determination of endothelin-3 like immunoreactivity in human plasma to investigate its possible role in hemodynamic alterations due to liver disease. Crossreactivity with other endothelin isoforms was always below 4 %, the lower detection limit following extraction on Sep-Pak C18 cartridges was 0.5 pg/ml. The concentration of endothelin-3 (mean ± SEM) was 4.16 ± 0.56 pg/ml (n = 13) in plasma of patients with cirrhosis of the liver, three fold higher than in age matched controls (1.35 ± 0.27 pg/ml, n = 12, p < 0.01). Plasma immunoreactivity was confirmed to be endothelin-3 related by reverse-phase HPLC. These data could suggest a role of plasma endothelin-3 in circulatory changes, as they occur in cirrhosis of the liver
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