Broken symmetry, excitons, gapless modes and topological excitations in Trilayer Quantum Hall systems

We study the interlayer coherent incompressible phase in Trilayer Quantum Hall systems (TLQH) at total filling factor $\nu_{T}=1$ from three approaches: Mutual Composite Fermion (MCF), Composite Boson (CB) and wavefunction approach. Just like in Bilayer Quantum Hall system, CB approach is superior than MCF approach in studying TLQH with broken symmetry. The Hall and Hall drag resistivities are found to be quantized at $h/e^{2}$. Two neutral gapless modes with linear dispersion relations are identified and the ratio of the two velocities is close to $\sqrt{3}$. The novel excitation spectra are classified into two classes: Charge neutral bosonic 2-body bound states and Charge $\pm 1$ fermionic 3-body bound states. In general, there are two 2-body Kosterlize-Thouless (KT) transition temperatures and one 3-body KT transition. The Charge $\pm 1$ 3-body fermionic bound states may be the main dissipation source of transport measurements. The broken symmetry in terms of $SU(3)$ algebra is studied. The structure of excitons and their flowing patterns are given. The coupling between the two Goldstone modes may lead to the broadening in the zero-bias peak in the interlayer correlated tunnelings of the TLQH. Several interesting features unique to TLQH are outlined. Limitations of the CB approach are also pointed out.Comment: 10 pages, 3 figures, Final version to be published in Phys. Rev.

Onset of Interlayer Phase Coherence in a Bilayer Two-Dimensional Electron System: Effect of Layer Density Imbalance

Tunneling and Coulomb drag are sensitive probes of spontaneous interlayer phase coherence in bilayer two-dimensional electron systems at total Landau level filling factor $\nu_T = 1$. We find that the phase boundary between the interlayer phase coherent state and the weakly-coupled compressible phase moves to larger layer separations as the electron density distribution in the bilayer is imbalanced. The critical layer separation increases quadratically with layer density difference.Comment: 4 pages, 3 figure

Android Malware Clustering through Malicious Payload Mining

Clustering has been well studied for desktop malware analysis as an effective triage method. Conventional similarity-based clustering techniques, however, cannot be immediately applied to Android malware analysis due to the excessive use of third-party libraries in Android application development and the widespread use of repackaging in malware development. We design and implement an Android malware clustering system through iterative mining of malicious payload and checking whether malware samples share the same version of malicious payload. Our system utilizes a hierarchical clustering technique and an efficient bit-vector format to represent Android apps. Experimental results demonstrate that our clustering approach achieves precision of 0.90 and recall of 0.75 for Android Genome malware dataset, and average precision of 0.98 and recall of 0.96 with respect to manually verified ground-truth.Comment: Proceedings of the 20th International Symposium on Research in Attacks, Intrusions and Defenses (RAID 2017

Kecelakaan Kerja pada Pekerja Konstruksi Informal di Kelurahan “X” Kota Samarinda

Industri konstruksi menempati peringkat pertama pekerjaan paling berbahaya serta penyumbang tingginya angka kecelakaan kerja baik di dunia maupun di Indonesia. Secara umum kecelakaan kerja disebabkanUnsafe Act dan Unsafe Condition. Penelitian ini bertujuan untuk menganalisis hubungan perilaku tidak aman dan kondisi tidak aman dengan kejadian kecelakaan kerja pada pekerja konstruksi informal di Kelurahan X Samarinda. Penelitian survei analitik dengan pendekatancross sectional telah dilakukan bulan Maret - Mei 2015 pada 40 orangpekerja. Variabel bebas terdiri dari perilaku pekerja tidak aman dan kondisi kerja tidak aman, sementara variabel terikat adalah kecelakaan kerja. Alat ukur penelitian menggunakan kuesioner yang disusun mengacu pada Loss Causation Model dan telah teruji cukup valid dan reliabel. Analisa data menggunakan uji chi square dengan batas kemaknaan α = 0,05. Disimpulkan ada hubungan unsafe act dan unsafe condition dengan kecelakaan kerja dengan p value masing-masing 0.038 dan 0.026. Jenis tindakan tidak aman yang paling banyak dilakukan adalah posisi kerja berbahaya, menjalankan mesin dengan kecepatan yang membahayakan dan serta mengangkat/mengangkut dengan cara yang salah, sedangkan kondisi tidak aman terdiri dari kelayakan dan kerapihan tempat kerja, pelindung/pembatas tidak layak, kondisi APD tidak layak, sistem peringatan yang tidak memadai dan bahaya kebakaran

Geogenomic segregation and temporal trends of human pathogenic Escherichia coli o157:H7, Washington, USA, 2005-2014

The often-noted and persistent increased incidence of Escherichia coli O157:H7 infections in rural areas is not well understood. We used a cohort of E. coli O157:H7 cases reported in Washington, USA, during 2005–2014, along with phylogenomic characterization of the infecting isolates, to identify geographic segregation of and temporal trends in specific phylogenetic lineages of E. coli O157:H7. Kernel estimation and generalized additive models demonstrated that pathogen lineages were spatially segregated during the period of analysis and identified a focus of segregation spanning multiple, predominantly rural, counties for each of the main clinical lineages, Ib, IIa, and IIb. These results suggest the existence of local reservoirs from which humans are infected. We also noted a secular increase in the proportion of lineage IIa and IIb isolates. Spatial segregation by phylogenetic lineage offers the potential to identify local reservoirs and intervene to prevent continued transmission

Animal-assisted pedagogy:human-animal bond, developmental benefits and practical considerations

Abstract. In recent years, animal-assisted pedagogy (AAP) has gained more attention both in the media and in the educational field. Some schools and libraries have seemed to include animals as a common support in the learning process. This has sparked interest also in educational research, and thus the effects of animals as a part of education have been studied more closely. For this reason, we aim to provide insight to AAP with a literature review that explores this topic from the points of view of human-animal bond, the developmental benefits, and the practical considerations related to it. In addition, we aspire to challenge our own views of AAP and discuss how it might be brought into practice. Based on our research, the human-animal bond is a mutually beneficial relationship that takes place between a human and an animal. Its significance in society and the multitude of benefits it offers, provide a good foundation from which to view AAP. Implementing AAP positively affects the social and emotional competences and motivation of students by the support of the comfort of the animal’s presence, which enables positive experiences and interactions. The animals help to create a safe space that allows the students to feel more confident and secure, and as a result the motivation of learning increases. However, it appears that applying AAP to practice is quite challenging due to the amount of limitations and consideration of bringing an animal into a working environment. For example, allergies, fears and lack of resources may dictate whether it is possible for an educator to practice AAP

Spin Susceptibility and Gap Structure of the Fractional-Statistics Gas

This paper establishes and tests procedures which can determine the electron energy gap of the high-temperature superconductors using the $t\!-\!J$ model with spinon and holon quasiparticles obeying fractional statistics. A simpler problem with similar physics, the spin susceptibility spectrum of the spin 1/2 fractional-statistics gas, is studied. Interactions with the density oscillations of the system substantially decrease the spin gap to a value of $(0.2 \pm 0.2)$ $\hbar \omega_c$, much less than the mean-field value of $\hbar\omega_c$. The lower few Landau levels remain visible, though broadened and shifted, in the spin susceptibility. As a check of the methods, the single-particle Green's function of the non-interacting Bose gas viewed in the fermionic representation, as computed by the same approximation scheme, agrees well with the exact results. The same mechanism would reduce the gap of the $t\!-\!J$ model without eliminating it.Comment: 35 pages, written in REVTeX, 16 figures available upon request from [email protected]

Spin Transition in Strongly Correlated Bilayer Two Dimensional Electron Systems

Using a combination of heat pulse and nuclear magnetic resonance techniques we demonstrate that the phase boundary separating the interlayer phase coherent quantum Hall effect at $\nu_T = 1$ in bilayer electron gases from the weakly coupled compressible phase depends upon the spin polarization of the nuclei in the host semiconductor crystal. Our results strongly suggest that, contrary to the usual assumption, the transition is attended by a change in the electronic spin polarization.Comment: 4 pages, 3 postscript figur

Carry-Over Effect in Forage Rotations on Newly Reclaimed Sandy Soil in Egypt

This study was carried out to investigate the carry-over effect of a preceding crop on the productivity of the following crop in various rotations in newly reclaimed lands in Egypt. The productivity of peanut (Arachis hypogaea L.), soyabean (Glycine max (L.) Merr.), maize (Zea mays L.) and pearl millet (Pennisetum glaucum (L.) R. Br.) in summer season were much higher following berseem (Trifolium alexandrinum L.) or lentil (Lens culinaris Medic) than after wheat (Triticum aestivum L.) or barley (Hordeum vulgare L.) in both years of the study. Soyabean was the best summer season pre-crop for lentil and berseem, whereas peanut was best for barley. Maize was a suprisingly good pre-crop in this study. The carry-over effect from pearl millet was inferior to that of maize. Of the winter season crops berseem had the most positive effect on the four summer crops studied. Winter season crops had a decreasing positive effect in the order: berseem, lentil, barley and wheat. The data suggest that, cropping systems on newly reclaimed sandy soils should include legume crops (soyabean or peanut in summer, and berseem or lentil in winter) to maximise production of the following crop