Fluctuation of Conductance Peak Spacings in Large Semiconductor Quantum Dots

Fluctuation of Coulomb blockade peak spacings in large two-dimensional semiconductor quantum dots are studied within a model based on the electrostatics of several electron islands among which there are random inductive and capacitive couplings. Each island can accommodate electrons on quantum orbitals whose energies depend also on an external magnetic field. In contrast with a single island quantum dot, where the spacing distribution is close to Gaussian, here the distribution has a peak at small spacing value. The fluctuations are mainly due to charging effects. The model can explain the occasional occurrence of couples or even triples of closely spaced Coulomb blockade peaks, as well as the qualitative behavior of peak positions with the applied magnetic field.Comment: 13 pages, 4 figures, accepted for publication in PR

Energy transfer, pressure tensor and heating of kinetic plasma

Kinetic plasma turbulence cascade spans multiple scales ranging from macroscopic fluid flow to sub-electron scales. Mechanisms that dissipate large scale energy, terminate the inertial range cascade and convert kinetic energy into heat are hotly debated. Here we revisit these puzzles using fully kinetic simulation. By performing scale-dependent spatial filtering on the Vlasov equation, we extract information at prescribed scales and introduce several energy transfer functions. This approach allows highly inhomogeneous energy cascade to be quantified as it proceeds down to kinetic scales. The pressure work, $-\left( \boldsymbol{P} \cdot \nabla \right) \cdot \boldsymbol{u}$, can trigger a channel of the energy conversion between fluid flow and random motions, which is a collision-free generalization of the viscous dissipation in collisional fluid. Both the energy transfer and the pressure work are strongly correlated with velocity gradients.Comment: 28 pages, 10 figure

Classification of Overlapped Audio Events Based on AT, PLSA, and the Combination of Them

Audio event classification, as an important part of Computational Auditory Scene Analysis, has attracted much attention. Currently, the classification technology is mature enough to classify isolated audio events accurately, but for overlapped audio events, it performs much worse. While in real life, most audio documents would have certain percentage of overlaps, and so the overlap classification problem is an important part of audio classification. Nowadays, the work on overlapped audio event classification is still scarce, and most existing overlap classification systems can only recognize one audio event for an overlap. In this paper, in order to deal with overlaps, we innovatively introduce the author-topic (AT) model which was first proposed for text analysis into audio classification, and innovatively combine it with PLSA (Probabilistic Latent Semantic Analysis). We propose 4 systems, i.e. AT, PLSA, AT-PLSA and PLSA-AT, to classify overlaps. The 4 proposed systems have the ability to recognize two or more audio events for an overlap. The experimental results show that the 4 systems perform well in classifying overlapped audio events, whether it is the overlap in training set or the overlap out of training set. Also they perform well in classifying isolated audio events

Symmetries of SU(2) Skyrmion in Hamiltonian and Lagrangian approaches

We apply the Batalin-Fradkin-Tyutin (BFT) method to the SU(2) Skyrmion to study the full symmetry structure of the model at the first class Hamiltonian level. On the other hand, we also analyze the symmetry structure of the action having the WZ term, which corresponds to this Hamiltonian, in the framework of the Lagrangian approach. Furthermore, following the BFV formalism we derive the BRST invariant gauge fixed Lagrangian from the above extended action.Comment: 14 pages, final revised version, to appear in Mod. Phys. Lett.

Evolution of Iron Kα_{\alpha} Line Emission in the Black Hole Candidate GX 339-4

GX 339-4 was regularly monitored with RXTE during a period (in 1999) when its X-ray flux decreased significantly (from 4.2$\times 10^{-10}$ erg cm$^{-2} s^{-1}$ to 7.6$\times 10^{-12}$ erg cm$^{-2}$s$^{-1}$ in the 3--20 keV band), as the source settled into the ``off state''. Our spectral analysis revealed the presence of a prominent iron K$_{\alpha}$ line in the observed spectrum of the source for all observations. The line shows an interesting evolution: it is centered at $\sim$6.4 keV when the measured flux is above 5$\times 10^{-11}$ erg cm$^{-2} s^{-1}$, but is shifted to $\sim$6.7 keV at lower fluxes. The equivalent width of the line appears to increase significantly toward lower fluxes, although it is likely to be sensitive to calibration uncertainties. While the fluorescent emission of neutral or mildly ionized iron atoms in the accretion disk can perhaps account for the 6.4 keV line, as is often invoked for black hole candidates, it seems difficult to understand the 6.7 keV line with this mechanism, because the disk should be less ionized at lower fluxes (unless its density changes drastically). On the other hand, the 6.7 keV line might be due to recombination cascade of hydrogen or helium like iron ions in an optically thin, highly ionized plasma. We discuss the results in the context of proposed accretion models.Comment: 18 pages, 2 figures, accepted for publication in the ApJ in v552n2p May 10, 2001 issu

A novel objective no-reference metric for digital video quality assessment

A novel objective no-reference metric is proposed for video quality assessment of digitally coded videos containing natural scenes. Taking account of the temporal dependency between adjacent images of the videos and characteristics of the human visual system, the spatial distortion of an image is predicted using the differences between the corresponding translational regions of high spatial complexity in two adjacent images, which are weighted according to temporal activities of the video. The overall video quality is measured by pooling the spatial distortions of all images in the video. Experiments using reconstructed video sequences indicate that the objective scores obtained by the proposed metric agree well with the subjective assessment scores

Complete mitochondrial genome of Prismognathus prossi (Coleoptera: Lucanidae) with phylogenetic implications

The complete mitochondrial genome of a Chinese stag beetle, Prismognathus prossi, was generated using the Illumina next-generation sequencing. The mitogenome sequence is 15,984 bp in length, the nucleotide composition isA 36.6%, C17.5%, T34.3% andG11.6%with theAT-content of 70.9%. The sequence has similar features with other reported insectmitogenomes, consisting of 13 proteincoding genes (PCGs), 22 transferRNAgenes, tworibosomalRNAsand a control region. All of the protein-coding genes start with the typicalATNinitiation codon except for COI. Maximum Likelihood (ML) and Bayesian Inference (BI) indicated that P. prossi share an affinity with Lucanus mazama, Lucanus fortunei and Cyclommatus vitalisi

Faktor-Faktor yang Mempengaruhi Tingkat Profitabilitas Bank Pembiayaan Rakyat Syariah (BPRS) di Aceh

Profitabilitas bank merupakan kualitas yang dinilai berdasarkan keadaan dan kemampuan suatu bank dalam menghasilkan laba. Penelitian ini bertujuan untuk menguji faktor-faktor yang mempengaruhi tingkat profitabilitas Bank Pembia yaan Rakyat Syariah (BPRS) di Aceh. Profitabilitas dalam penelitian ini diukur dengan menggunakan dua rasio, yaitu return on asset dan return on equity, dengan menggunakan empat faktor yaitu pembiayaan, dana pihak ketiga, financing to deposit ratio dan non performing financing. Metode yang digunakan dalam penelitian ini adalah metode kuantitatif.Adapun sampel yang digunakan adalah Bank Pembiayaan Rakyat Syariah (BPRS) di Aceh yang berjumlah 10 bank dan dipilih berdasarkan metode purposive sampling dengan 140 data pengamatan.Pengamatan dilakukan dari tahun 2010 sampai dengan kuartal III tahun 2015. Hasil penelitian dapat disimpulkan bahwa secara simultan variabel pembiayaan, dana pihak ketiga, financing to deposit ratio dan non performing financing berpengaruh signifikan terhadap return on asset dan return on equity. Untuk pengujian secara parsial, seluruh variabel independen yaitu pembiayaan, dana pihak ketiga, financing to deposit ratio dan non performing financing berpengaruh signifikan terhadap return on asset. Sedangkan terhadap return on equity, hanya variabel dana pihak ketiga dan financing to deposit ratio yang berpengaruh signifikan. Adapun variabel pembiayaan dan non performing financing tidak berpengaruh signifikan terhadap return on equity