665 research outputs found
On the Reverse Engineering of the Citadel Botnet
Citadel is an advanced information-stealing malware which targets financial
information. This malware poses a real threat against the confidentiality and
integrity of personal and business data. A joint operation was recently
conducted by the FBI and the Microsoft Digital Crimes Unit in order to take
down Citadel command-and-control servers. The operation caused some disruption
in the botnet but has not stopped it completely. Due to the complex structure
and advanced anti-reverse engineering techniques, the Citadel malware analysis
process is both challenging and time-consuming. This allows cyber criminals to
carry on with their attacks while the analysis is still in progress. In this
paper, we present the results of the Citadel reverse engineering and provide
additional insight into the functionality, inner workings, and open source
components of the malware. In order to accelerate the reverse engineering
process, we propose a clone-based analysis methodology. Citadel is an offspring
of a previously analyzed malware called Zeus; thus, using the former as a
reference, we can measure and quantify the similarities and differences of the
new variant. Two types of code analysis techniques are provided in the
methodology, namely assembly to source code matching and binary clone
detection. The methodology can help reduce the number of functions requiring
manual analysis. The analysis results prove that the approach is promising in
Citadel malware analysis. Furthermore, the same approach is applicable to
similar malware analysis scenarios.Comment: 10 pages, 17 figures. This is an updated / edited version of a paper
appeared in FPS 201
Analytical and Numerical Evaluations of Flexible V-Band Rotman Lens Beamforming Network Performance for Conformal Wireless Subsystems
This paper presents the analytical design and numerical performance evaluation of novel V-band millimetre-wave (mm-wave) beamforming networks (BFNs), based on the Rotman lens array feeding concept. The devices are intended for operation in the unlicensed 60-GHz frequency band. The primary objective of this work is to study the feasibility of designing flexible V-band beamformers, based on liquid-crystal polymer (LCP) substrates. The planar Rotman lens device has been initially developed, and the output performances, in terms of the scattering parameters and accuracy, have been analysed. This is further continued with the detailed designs of the Rotman lens BFNs based on the four different proposed flexural cases, namely the concave-axial bending, the convex-axial bending, the concave-circumferential bending, and the convex-circumferential bending. Each of the flexures has been analysed, and the performance in terms of the surface currents and phase distributions, as the primary functionality indicators, has been presented. The presented flexible beamformers exhibit significant characteristics to be potentially employed as low-cost and efficient units of the mm-wave transceivers with the in-built electronic beam steering capabilities for the conformal wireless subsystems
Impact of Performing Health Promotion Model Intervention on Physical Activity of Health Volunteer of Torbat-e-Jam City, Iran
Abstract Aims: Regular physical activity can reduce the burden of chronic diseases, such as heart disease, diabetes, and some cancers, and can prevent early death. This study examined the impact of performing health promotion model intervention on physical activity of the health volunteers. Materials & Methods: This cross-sectional research is part of a three-month Intervening study started in 2015 on 80 health volunteers in Torbat-e Jaam City, Iran, which was selected by multistage random sampling method and participants were divided into two interventional and control groups. A Demographic Questionnaire and The Persian version of International Physical Activity Questionnaire were used to collect data. The data was analyzed in SPSS 16 using independent T, Pearson's correlation coefficient and linear regression tests. Findings: Before the intervention the mean of perceived benefit score was 31.3±4.5 that was evaluated as “good” but self-efficacy and behavior scores were 5.8±4.1 and 912.4±750.8 that were assessed as “poor”. Physical activity had positive correlation with perceived benefits, self-efficacy, commitment, positive, emotion and situational influences and a negative correlation with perceived barriers. Overall 66.8 of the physical activity was predicted by Pender’s Health Promotion Model variables. There was a significant difference between the mean scores of physical activity and other structures of HPM in the experimental group after the intervention and its score before intervention. Conclusion: Educational program based on Pender's health promotion model is effective in improving physical activity of health volunteers
A Tuned and Scalable Fast Multipole Method as a Preeminent Algorithm for Exascale Systems
Among the algorithms that are likely to play a major role in future exascale
computing, the fast multipole method (FMM) appears as a rising star. Our
previous recent work showed scaling of an FMM on GPU clusters, with problem
sizes in the order of billions of unknowns. That work led to an extremely
parallel FMM, scaling to thousands of GPUs or tens of thousands of CPUs. This
paper reports on a a campaign of performance tuning and scalability studies
using multi-core CPUs, on the Kraken supercomputer. All kernels in the FMM were
parallelized using OpenMP, and a test using 10^7 particles randomly distributed
in a cube showed 78% efficiency on 8 threads. Tuning of the
particle-to-particle kernel using SIMD instructions resulted in 4x speed-up of
the overall algorithm on single-core tests with 10^3 - 10^7 particles. Parallel
scalability was studied in both strong and weak scaling. The strong scaling
test used 10^8 particles and resulted in 93% parallel efficiency on 2048
processes for the non-SIMD code and 54% for the SIMD-optimized code (which was
still 2x faster). The weak scaling test used 10^6 particles per process, and
resulted in 72% efficiency on 32,768 processes, with the largest calculation
taking about 40 seconds to evaluate more than 32 billion unknowns. This work
builds up evidence for our view that FMM is poised to play a leading role in
exascale computing, and we end the paper with a discussion of the features that
make it a particularly favorable algorithm for the emerging heterogeneous and
massively parallel architectural landscape
Assessing the Physical Activity of Health Volunteers Based on the Pender's Health Promotion Model
Abstract Aims: Physical inactivity has been identified as the 4th leading risk factor for global mortality causing an estimated of 3.2million deaths per year. This study aimed to assess the physical activity of health volunteers with Pender's Health Promotion Model. Instrument & Methods: This cross-sectional analytical study was performed on 80 health volunteers in Torbat-e-Jam City, Iran, in 2015. A researcher-made questionnaire with the following sections was used to gather data; perceived benefits, perceived barriers, self-efficacy, interpersonal influences, positive emotion, commitment, modeling and competing preferences. SPSS 16 sofware was used to analyze data by independent T, Pearson's correlation coefficient and linear regression tests. Findings: There was no significant difference between the scores according to educational levels, age groups, BMI score, marital status, habitat and experience as a health volunteer duration. Physical activity had positive correlation with perceived benefits, self-efficacy, commitment, positive emotion and situational influences and a negative correlation with perceived barriers. Situational influences, as the strongest predictor of the physical activity, predicted 35.1 of it and then positive emotions predicted 34.7 and self-efficacy predicted 23.4 of physical activity. Conclusion: The level of physical activity in health volunteers of Torbat-e-Jam City, Iran, is not appropriate and is less than moderate
A novel semi-active TMD with folding variable stiffness spring
An innovative variable stiffness device is proposed and investigated based on numerical simulations. The device, called a folding variable stiffness spring (FVSS), can be widely used, especially in tuned mass dampers (TMDs) with adaptive stiffness. An important characteristic of FVSS is its capability to change the stiffness between lower and upper bounds through a small change of distance between its supports. This special feature results in lower time-lag errors and readjustment in shorter time intervals. The governing equations of the device are derived and simplified for a symmetrical FVSS with similar elements. This device is then used to control a single-degree-of-freedom (SDOF) structure as well as a multi-degree-of-freedom (MDOF) structure via a semi-active TMD. Numerical simulations are conducted to compare several control cases for these structures. To make it more realistic, a real direct current motor with its own limitations is simulated in addition to an ideal control case with no limitations and both the results are compared. It is shown that the proposed device can be effectively used to suppress undesirable vibrations of a structure and considerably improves the performance of the controller compared to a passive device
Telemedicine - a scientometric and density equalizing analysis
Background As a result of the various telemedicine projects in the past years
a large number of studies were recently published in this field. However, a
precise bibliometric analysis of telemedicine publications does not exist so
far. Methods The present study was conducted to establish a data base of the
existing approaches. Density-equalizing algorithms were used and data was
retrieved from the Thomson Reuters database Web of Science. Results During the
period from 1900 to 2006 a number of 3290 filed items were connected to
telemedicine, with the first being published in 1964. The studies originate
from 101 countries, with the USA, Great Britain and Canada being the most
productive suppliers participating in 56.08 % of all published items.
Analyzing the average citation per item for countries with more than 10
publications, Ireland ranked first (10.19/item), New Zealand ranked second
(9.5/item) followed by Finland (9.04/item). The citation rate can be assumed
as an indicator for research quality. The ten most productive journals include
three journals with the main focus telemedicine and another five with the main
focus “Information/Informatics”. In all subject categories examined for
published items related to telemedicine, “Health Care Sciences & Services”
ranked first by far. More than 36 % of all publications are assigned to this
category, followed by “Medical Informatics” with 9.72 % and “Medicine, General
& Internal” with 8.84 % of all publications. Conclusion In summary it can be
concluded that the data shows clearly a strong increase in research
productivity. Using science citation analysis it can be assumed that there is
a large rise in the interest in telemedicine studies
Carvedilol Compared With Metoprolol on Left Ventricular Ejection Fraction After Coronary Artery Bypass Graft
A number of elective coronary artery bypass graft (CABG) surgery patients have impaired underlying left ventricular function (poor ejection fraction). This study was performed to compare the effect of postoperative oral carvedilol versus metoprolol on left ventricular ejection fraction (LVEF) after CABG compared with metoprolol. In a double-blind clinical trial, 60 patients with coronary artery disease, aged 35 to 65 years, who had an ejection fraction of 15% to 35% were included. Either carvedilol or metoprolol was administered the day after CABG The patients were evaluated by the same cardiologist 14 days before and 2 and 6 months after elective CABG The results demonstrated better improvements in LVEF in the carvedilol group. No difference regarding postoperative arrhythmias or mortality was detected. The results suggest that carvedilol may exert more of an improved myocardial effect than metoprolol for the low ejection fraction patients undergoing CABG in the early postoperative months
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