A Study of the Relationship Between Antivirus Regressions and Label Changes

AntiVirus (AV) products use multiple components to detect malware. A component which is found in virtually all AVs is the signature-based detection engine: this component assigns a particular signature label to a malware that the AV detects. In previous analysis [1-3], we observed cases of regressions in several different AVs: i.e. cases where on a particular date a given AV detects a given malware but on a later date the same AV fails to detect the same malware. We studied this aspect further by analyzing the only externally observable behaviors from these AVs, namely whether AV engines detect a malware and what labels they assign to the detected malware. In this paper we present the results of the analysis about the relationship between the changing of the labels with which AV vendors recognize malware and the AV regressions

Improved measurement technique for the characterisation of phase change materials using the T-history method

Recently the interest in Phase Change Materials (PCMs) has grown significantly amongst researchers [1-9]. Namely, these materials, due to their ability to store large amounts of thermal energy in relatively small temperature intervals, can be effectively used for various thermal energy storage (TES) applications. Nevertheless, accurate knowledge of the thermal properties of PCMs is a prerequisite before design processes and real time deployments of any TES applications. The T-history method is widely used for the investigation of phase change materials. The majority of the T-history studies reported in the literature during the last 20 years aim to reduce the temperature and the heat storage uncertainty associated with the PCMs measurement [3-9]. Reduction of these uncertainties is important since it should provide better material utilisation. This paper presents an improved measurement technique for the characterisation of PCMs using the T-history method. The main modifications involved in the measurement process are briefly summarized below. Primarily, suggested improvements include the selection of the thermally controlled environment and the temperature sensing modalities for the T-history setup. This was followed by the development of the adequate instrumentation and data acquisition system. In addition, the mathematical model given by Marin et al. was adjusted for the data analysis in order to take the subcooling phenomenon into account. The calculated results on heat capacity were presented as heat density in given temperature intervals, as suggested by Mehling et al. Moreover, the determination of the total phase change heat in case of both cooling and heating cycles showed that the reduction of relevant temperature and heat storage uncertainties was achieved

Comparison of thermistor linearization techniques for accurate temperature measurement in phase change materials

Alternate energy technologies are developing rapidly in the recent years. A significant part of this trend is the development of different phase change materials (PCMs). Proper utilization of PCMs requires accurate thermal characterization. There are several methodologies used in this field. This paper stresses the importance of accurate temperature measurements during the implementation of T-history method. Since the temperature sensor size is also important thermistors have been selected as the sensing modality. Two thermistor linearization techniques, one based on Wheatstone bridge and the other based on simple serial-parallel resistor connection, are compared in terms of achievable temperature accuracy through consideration of both, nonlinearity and self-heating errors. Proper calibration was performed before T-history measurement of RT21 (RUBITHERM® GmbH) PCM. Measurement results suggest that the utilization of serial-parallel resistor connection gives better accuracy (less than ±0.1°C) in comparison with the Wheatstone bridge based configuration (up to ±1.5°C)

ICN as Network Infrastructure for Multi-Sensory Devices: Local Domain Service Discovery for ICN-based IoT Environments

Information Centric Networking (ICN) is an emerging research topic aiming at shifting the Internet from its current host-centric paradigm towards an approach centred around content, which enables the direct retrieval of information objects in a secure, reliable, scalable, and efficient way. The exposure of ICN to scenarios other than static content distribution is a growing research topic, promising to extend the impact of ICN to a broader scale. In this context, particular attention has been given to the application of ICN in Internet of Things (IoT) environments. The current paper, by focusing on local domain IoT scenarios, such as multi-sensory Machine to Machine environments, discusses the challenges that ICN, particularly Interest-based solutions, impose to service discovery. This work proposes a service discovery mechanism for such scenarios, relying on an alternative forwarding pipeline for supporting its core operations. The proposed mechanism is validated through a proof-of-concept prototype, developed on top of the Named Data Networking ICN architecture, with results showcasing the benefits of our solution for discovering services within a collision domain. © 2017 Springer Science+Business Media New Yor

Target and beam-target spin asymmetries in exclusive pion electroproduction for Q2>1GeV2 . I. ep→eπ+n

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π + electroproduction reaction γ ∗ p → n π + . The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic range covered is 1.1 < W < 3 GeV and 1 < Q 2 < 6 GeV 2 . Results were obtained for about 6000 bins in W ,   Q 2 ,   cos ( θ ∗ ) , and ϕ ∗ . Except at forward angles, very large target-spin asymmetries are observed over the entire W region. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but very large differences are seen at higher values of W . A generalized parton distributions (GPD)-based model is in poor agreement with the data. When combined with cross-sectional measurements, the present results provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q 2 , for resonances with masses as high as 2.4 GeV

Mixing in Circular and Non-circular Jets in Crossflow

Coherent structures and mixing in the flow field of a jet in crossflow have been studied using computational (large eddy simulation) and experimental (particle image velocimetry and laser-induced fluorescence) techniques. The mean scalar fields and turbulence statistics as determined by both are compared for circular, elliptic, and square nozzles. For the latter configurations, effects of orientation are considered. The computations reveal that the distribution of a passive scalar in a cross-sectional plane can be single- or double-peaked, depending on the nozzle shape and orientation. A proper orthogonal decomposition of the transverse velocity indicates that coherent structures may be responsible for this phenomenon. Nozzles which have a single-peaked distribution have stronger modes in transverse direction. The global mixing performance is superior for these nozzle types. This is the case for the blunt square nozzle and for the elliptic nozzle with high aspect ratio. It is further demonstrated that the flow field contains large regions in which a passive scalar is transported up the mean gradient (counter-gradient transport) which implies failure of the gradient diffusion hypothesis

Comments on the article Opial inequality in q-Calculus

We give corrections concerned with the proofs of the theorems from the paper Opial inequality in q-Calculus, where integral inequalities of the q-Opial type were established

Photoproduction of K+K− meson pairs on the proton

The exclusive reaction γp→pK+K− was studied in the photon energy range 3.0–3.8  GeV and momentum transfer range 0.6<−t<1.3  GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range the integrated luminosity was approximately 20  pb−1. The reaction was isolated by detecting the K+ and the proton in CLAS, and reconstructing the K− via the missing-mass technique. Moments of the dikaon decay angular distributions were extracted from the experimental data. Besides the dominant contribution of the ϕ meson in the P wave, evidence for S−P interference was found. The differential production cross sections dσ/dt for individual waves in the mass range of the ϕ resonance were extracted and compared to predictions of a Regge-inspired model. This is the first time the t-dependent cross section of the S-wave contribution to the elastic K+K− photoproduction has been measured