Cost monotonicity, consistency and minimum cost spanning tree games

We propose a new cost allocation rule for minimum cost spanning tree games. The new rule is a core selection and also satisfies cost monotonicity. We also give characterization theorems for the new rule as well as the much-studied Bird allocation. We show that the principal difference between these two rules is in terms of their consistency properties

Cost monotonicity, consistency and minimum cost spanning tree games

We propose a new cost allocation rule for minimum cost Spanning tree games. The new rule is a core selection and also satisfices cost monotonicity. We also give charqcterization theorems for the new rule as well as the much-studied Bird allocation. We show that the principal difference between these two rules is interms of their consistency properties.spanning tree, cost allocation, core selection, cost monotonicity, consistency

Generating a second-order topological insulator with multiple corner states by periodic driving

We study the effects of periodic driving on a variant of the Bernevig-Hughes-Zhang (BHZ) model defined on a square lattice. In the absence of driving, the model has both topological and nontopological phases depending on the different parameter values. We also study the anisotropic BHZ model and show that, unlike the isotropic model, it has a nontopological phase which has states localized on only two of the four edges of a finite-sized square. When an appropriate term is added, the edge states get gapped and gapless states appear at the four corners of a square; we have shown that these corner states can be labeled by the eigenvalues of a certain operator. When the system is driven periodically by a sequence of two pulses, multiple corner states may appear depending on the driving frequency and other parameters. We discuss to what extent the system can be characterized by topological invariants such as the Chern number and a diagonal winding number. We have shown that the locations of the jumps in these invariants can be understood in terms of the Floquet operator at both the time-reversal invariant momenta and other momenta which have no special symmetries.Comment: 14 pages, 29 figures; new discussion, figures, and references adde

Color quality - A visual comparison between IQ colour and ICC based color management

Color management has become central to achieving greater color quality and consistency and has become an integral part of a printing workflow. The contemporary printer is faced with the challenge of achieving high print and color quality in conjunction with low production cost to remain competitive. This thesis focuses on the subject of comparing the color quality obtained by implementing the IQ colour profiling system with respect to ICC profiling. The basis of this study is that the ultimate judge for color quality in the Graphic Arts industry is the print buyer and color quality should really be a function of human perception rather than complicated color measurements. The study used the responses provided by 15 observers for the purpose of this comparative visual study and the results were used to derive a conclusion pointing out the profiling methodology that provided better color quality. The research pointed out that the color quality obtained using IQ colour based profiling was much closer to the reference contone prints than ICC based profiling. ICC based prints were two times JND away from the reference images as compared to the IQ colour on a visual scale ranging from -3 to +3. It was also referenced from the visual paired comparisons that IQ colour based prints were better than ICC based prints in terms of overall color and image qualit

Bidirectional interactions between neuronal and hemodynamic responses to transcranial direct current stimulation (tDCS): challenges for brain-state dependent tDCS

Transcranial direct current stimulation (tDCS) has been shown to modulate cortical neural activity. During neural activity, the electric currents from excitable membranes of brain tissue superimpose in the extracellular medium and generate a potential at scalp, which is referred as the electroencephalogram (EEG). Respective neural activity (energy demand) has been shown to be closely related, spatially and temporally, to cerebral blood flow (CBF) that supplies glucose (energy supply) via neurovascular coupling. The hemodynamic response can be captured by near-infrared spectroscopy (NIRS), which enables continuous monitoring of cerebral oxygenation and blood volume. This neurovascular coupling phenomenon led to the concept of neurovascular unit (NVU) that consists of the endothelium, glia, neurons, pericytes, and the basal lamina. Here, recent works suggest NVU as an integrated system working in concert using feedback mechanisms to enable proper brain homeostasis and function where the challenge remains in capturing these mostly nonlinear spatiotemporal interactions within NVU during tDCS. Therefore, we propose EEG-NIRS-based whole-head monitoring of tDCS-induced neuronal and hemodynamic alterations for brain-state dependent tDCS

Possible explanation of indirect gamma ray signatures from hidden sector fermionic dark matter

We propose the existence of a hidden or dark sector besides the standard model (SM) of particle physics, whose members (both fermionic and bosonic) obey a local SU(2)$_{\rm H}$ gauge symmetry while behaving like a singlet under the SM gauge group. However, the fermiomic fields of the dark sector also possess another global U(1)$_{\rm H}$ symmetry which remains unbroken. The local SU(2)$_{\rm H}$ invariance of the dark sector is broken spontaneously when a scalar field in this sector acquires a vacuum expectation value (VEV) and thereby generating masses to the dark gauge bosons and dark fermions charged under the SU(2)$_{\rm H}$. The lightest fermion in this dark SU(2)$_{\rm H}$ sector can be a potential dark matter candidate. We first examine the viability of the model and constrain the model parameter space by theoretical constraints such as vacuum stability and by the experimental constraints such as PLANCK limit on relic density, LHC data, limits on spin independent scattering cross-section from dark matter direct search experiments etc. We then investigate the gamma rays from the pair annihilation of the proposed dark matter candidate at the Galactic Centre region. We also extend our calculations of gamma rays flux for the case of dwarf galaxies and compare the signatures of gamma rays obtained from these astrophysical sites.Comment: 33 pages, 16 figures, title changed, major revisio