2,857 research outputs found
Cyber-threat detection system using a hybrid approach of transfer learning and multi-model image representation
Currently, Android apps are easily targeted by malicious network traffic because of their constant network access. These threats have the potential to steal vital information and disrupt the commerce, social system, and banking markets. In this paper, we present a malware detection system based on word2vec-based transfer learning and multi-model image representation. The proposed method combines the textual and texture features of network traffic to leverage the advantages of both types. Initially, the transfer learning method is used to extract trained vocab from network traffic. Then, the malware-to-image algorithm visualizes network bytes for visual analysis of data traffic. Next, the texture features are extracted from malware images using a combination of scale-invariant feature transforms (SIFTs) and oriented fast and rotated brief transforms (ORBs). Moreover, a convolutional neural network (CNN) is designed to extract deep features from a set of trained vocab and texture features. Finally, an ensemble model is designed to classify and detect malware based on the combination of textual and texture features. The proposed method is tested using two standard datasets, CIC-AAGM2017 and CICMalDroid 2020, which comprise a total of 10.2K malware and 3.2K benign samples. Furthermore, an explainable AI experiment is performed to interpret the proposed approach
Challenges and issues facing ethnic minority small business owners: the Scottish experience
Studies investigating the challenges and barriers faced by ethnic minority entrepreneurs have often concentrated on areas where there is a large supportive ethnic minority community. Less work has been conducted on the experience of those entrepreneurs operating in cities where such ethnic resources may be less widely available. Considered from the perspective of mixed embeddedness framework, this study uses face to face interviews with 25 ethnic minority entrepreneurs to gain a greater understanding of the constraints experienced by those starting and running businesses in one such location, the Scottish city of Aberdeen in the UK. Although, issues found by previous studies such as access to funding remain an issue, the entrepreneurs indicated problems with access to labour as United Kingdom Border Agency (UKBA) immigration rules and tightening of the Post Study Work (PSW) visa have had a profound effect on these entrepreneurs. The results imply that the weakening of the ethnic resource microsphere has not opened up opportunities which are exploited by the entrepreneurs, but they have still been exposed to external forces from the regulatory macrosphere. Both entrepreneurs and policymakers need to think carefully about the retention, training and recruitment of staff. In particular, the wider ramifications of immigration rule changes need to be considered, but also whether entrepreneurs need to be more open to the potential of recruiting non‐ethnic employees and if so what support is required to achieve this
A novel Multi-permittivity Cylindrical Dielectric Resonator Antenna for Wideband Applications
In this paper, a novel multi-permittivity cylindrical dielectric resonator antenna for wideband application is presented. The multi-permittivity cylinder is formed by combining two different permittivity material sectors in such a way that each sector (with constant permittivity) is 90 degree apart. A direct microstrip line coupling terminated with T-stub at the open end is used to excite the multi-permittivity cylindrical dielectric resonator. The angular position of the multi sector dielectric resonator with respect to the longitudinal axis of the microstrip line and length of the additional strip at the open end of the feeding circuit is key parameters for wideband operation of the antenna. By optimizing all parameters of the proposed antenna, wideband impedance bandwidth of 56% (12.1 GHz - 21.65 GHz) is achieved. The average gain of the antenna throughout the bandwidth is 5.9 dB with good radiation properties in both E-plane and H-plane. A well matched simulation and experimental results show that the antenna is suitable for wideband applications
Testing statistical bounds on entanglement using quantum chaos
Previous results indicate that while chaos can lead to substantial entropy
production, thereby maximizing dynamical entanglement, this still falls short
of maximality. Random Matrix Theory (RMT) modeling of composite quantum
systems, investigated recently, entails an universal distribution of the
eigenvalues of the reduced density matrices. We demonstrate that these
distributions are realized in quantized chaotic systems by using a model of two
coupled and kicked tops. We derive an explicit statistical universal bound on
entanglement, that is also valid for the case of unequal dimensionality of the
Hilbert spaces involved, and show that this describes well the bounds observed
using composite quantized chaotic systems such as coupled tops.Comment: 5 pages, 3 figures, to appear in PRL. New title. Revised abstract and
some changes in the body of the pape
p-GaAs nanowire MESFETs with near-thermal limit gating
Difficulties in obtaining high-performance p-type transistors and gate
insulator charge-trapping effects present two major challenges for III-V
complementary metal-oxide semiconductor (CMOS) electronics. We report a p-GaAs
nanowire metal-semiconductor field-effect transistor (MESFET) that eliminates
the need for a gate insulator by exploiting the Schottky barrier at the
metal-GaAs interface. Our device beats the best-performing p-GaSb nanowire
metal-oxide-semiconductor field effect transistor (MOSFET), giving a typical
sub-threshold swing of 62 mV/dec, within 4% of the thermal limit, on-off ratio
, on-resistance ~700 k, contact resistance ~30 k,
peak transconductance 1.2 S/m and high-fidelity ac operation at
frequencies up to 10 kHz. The device consists of a GaAs nanowire with an
undoped core and heavily Be-doped shell. We carefully etch back the nanowire at
the gate locations to obtain Schottky-barrier insulated gates whilst leaving
the doped shell intact at the contacts to obtain low contact resistance. Our
device opens a path to all-GaAs nanowire MESFET complementary circuits with
simplified fabrication and improved performance
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