708 research outputs found
Window-based Streaming Graph Partitioning Algorithm
In the recent years, the scale of graph datasets has increased to such a
degree that a single machine is not capable of efficiently processing large
graphs. Thereby, efficient graph partitioning is necessary for those large
graph applications. Traditional graph partitioning generally loads the whole
graph data into the memory before performing partitioning; this is not only a
time consuming task but it also creates memory bottlenecks. These issues of
memory limitation and enormous time complexity can be resolved using
stream-based graph partitioning. A streaming graph partitioning algorithm reads
vertices once and assigns that vertex to a partition accordingly. This is also
called an one-pass algorithm. This paper proposes an efficient window-based
streaming graph partitioning algorithm called WStream. The WStream algorithm is
an edge-cut partitioning algorithm, which distributes a vertex among the
partitions. Our results suggest that the WStream algorithm is able to partition
large graph data efficiently while keeping the load balanced across different
partitions, and communication to a minimum. Evaluation results with real
workloads also prove the effectiveness of our proposed algorithm, and it
achieves a significant reduction in load imbalance and edge-cut with different
ranges of dataset
Color Fields on the Light-Shell
We study the classical color radiation from very high energy collisions that
produce colored particles. In the extreme high energy limit, the classical
color fields are confined to a light-shell expanding at and are associated
with a non-linear -model on the 2D light-shell with specific symmetry
breaking terms. We argue that the quantum version of this picture exhibits
asymptotic freedom and may be a useful starting point for an effective
light-shell theory of the structure between the jets at a very high energy
collider.Comment: 11 pages, no figure
The Impact of Load Altering Attacks on Distribution Systems with ZIP Loads
Load-altering attacks (LAAs) pose a significant threat to power systems with
Internet of Things (IoT)-controllable load devices. This research examines the
detrimental impact of LAAs on the voltage profile of distribution systems,
taking into account the realistic load model with constant impedance Z,
constant current I, and constant power P (ZIP). We derive closed-form
expressions for computing the voltages of buses following LAA by making
approximations to the power flow as well as the load model. We also
characterize the minimum number of devices to be manipulated in order to cause
voltage safety violations in the system. We conduct extensive simulations using
the IEEE-33 bus system to verify the accuracy of the proposed approximations
and highlight the difference between the attack impacts while considering
constant power and the ZIP load model (which is more representative of
real-world loads)
Analysis of Infrastructure Investment and Institutional Quality on Living Standards: A Case Study of Pakistan (1990-2013)
In this study, the relationship of Infrastructure Investment
and Institutional Quality (CIM) on Living Standards of people was
analysed for Pakistan. This paper comprises of trend analysis of
institutional quality for different periods of governments of Pakistan
coupled with an empirical analysis of the model. The empirical estimates
are comprised of unit root test, Johansen Cointegration, VAR analysis
and Granger Causality tests for the sample of 1984– 2013. The trend
analysis depicts fluctuations of Institutional Quality in different
governments due to different political conditions of every period. The
empirical analysis shows that there exists long standing relationship
between the Institutional Quality, Infrastructure Investment and living
standards of people. However, the VAR analysis shows that the
coefficients of only Institutional Quality and Living Standards of
People (previous year i.e. lag variables) resulted significance in
affecting living standards of the people. The Granger causality result
shows bidirectional and uni-directional relationships among variables.
The results in our study indicate bi-directional relationships of Living
Standards of People (GDPC) with Institutional Quality (CIM). Secondly,
CIM and Infrastructure Investment (Developmental Expenditure) are having
uni-directional relationship. Thirdly, Population and Institutional
Quality (Contract Intensive Money) are having uni-directional
relationship. Fourthly, GDPC and Infrastructure Investment carry a
uni-directional relationship. JEL Classification: E02, F41, H53, O1, O4,
P23. Keywords: Institutional Quality (Contract Intensive Money (CIM),
Infrastructure Investment (Developmental Expenditure), Trade Openness,
GDP per Capita, and Population
Experimental Study on Ultimate Strength of Steel Tube Column Filled with Reactive Powder Concrete
Composite concrete Filled Tubular Steel (CFT) members, which have excellent deformability due to the well-known confined and constrained interaction between steel tube and concrete, have largely been utilized as bridge piers or columns in high-rise buildings, resulting in increased strength and decreased column size. This study examined the experimental performance of steel tube columns filled with reactive powder concrete (RPC) under axial compression. Three sets of columns were used in the experiment, each with variations in shape (square, rectangular, and circular), length-to-diameter ratio, and compressive strength of the RPC. The first set consisted of five columns, while the second and third sets each had seven columns with three different lengths (750 mm, 600 mm, and 450 mm) and two different compressive strengths (54 and 92 MPa). A new numerical model was developed to calculate the ultimate failure load of the columns by considering factors such as the yield strength of steel, the compressive strength of concrete, the column shape, and the ratio of concrete to steel. This model was validated by comparing the results obtained from the experiments to those predicted by the model, as well as by designing equations from various codes. The results showed that the proposed numerical model accurately predicted the ultimate failure load for columns filled with different types of concrete, especially for RPC, while maintaining conservatism compared to the ACI, AISC, and EN codes equations. Doi: 10.28991/CEJ-2023-09-06-04 Full Text: PD
An Empirical Study of the Use of Integrity Verification Mechanisms for Web Subresources
Web developers can (and do) include subresources such as scripts, stylesheets and images in their webpages. Such subresources might be stored on remote servers such as content delivery networks (CDNs). This practice creates security and privacy risks, should a subresource be corrupted, as was recently the case for the British Airways websites. The subresource integrity (SRI) recommendation, released in mid-2016 by the W3C, enables developers to include digests in their webpages in order for web browsers to verify the integrity of subresources before loading them. In this paper, we conduct the first large-scale longitudinal study of the use of SRI on the Web by analyzing massive crawls (3B unique URLs) of the Web over the last 3.5 years. Our results show that the adoption of SRI is modest (3.40%), but grows at an increasing rate and is highly influenced by the practices of popular library developers (e.g., Bootstrap) and CDN operators (e.g., jsDelivr). We complement our analysis about SRI with a survey of web developers (N =227): It shows that a substantial proportion of developers know SRI and understand its basic functioning, but most of them ignore important aspects of the specication, such as the case of malformed digests. The results of the survey also show that the integration of SRI by developers is mostly manual-hence not scalable and error prone. This calls for a better integration of SRI in build tools
Theoretical study of lepton events in the atmospheric neutrino experiments at SuperK
Super-Kamiokande has reported the results for the lepton events in the
atmospheric neutrino experiment. These results have been presented for a 22.5kT
water fiducial mass on an exposure of 1489 days, and the events are divided
into sub-GeV, multi-GeV and PC events. We present a study of nuclear medium
effects in the sub-GeV energy region of atmospheric neutrino events for the
quasielastic scattering, incoherent and coherent pion production processes, as
they give the most dominant contribution to the lepton events in this energy
region. We have used the atmospheric neutrino flux given by Honda et al. These
calculations have been done in the local density approximation. We take into
account the effect of Pauli blocking, Fermi motion, Coulomb effect,
renormalization of weak transition strengths in the nuclear medium in the case
of the quasielastic reactions. The inelastic reactions leading to production of
leptons along with pions is calculated in a - dominance model by
taking into account the renormalization of properties in the nuclear
medium and the final state interaction effects of the outgoing pions with the
residual nucleus. We present the results for the lepton events obtained in our
model with and without nuclear medium effects, and compare them with the Monte
Carlo predictions used in the simulation and the experimentally observed events
reported by the Super-Kamiokande collaboration.Comment: 23 pages, 13 figure
Copper-nickel oxide nanofilm modified electrode for non-enzymatic determination of glucose
CuxO-NiO nanocomposite film for the non-enzymatic determination of glucose was prepared by the novel modifying method. At first, anodized Cu electrode was kept in a mixture solution of CuSO4, NiSO4 and H2SO4 for 15 minutes. Then, a cathodization process with a step potential of -6 V in a mixture solution of CuSO4 and NiSO4 was initiated, generating formation of porous Cu-Ni film on the bare Cu electrode by electrodeposition assisted by the release of hydrogen bubbles acting as soft templates. Optimized conditions were determined by the experimental design software for electrodeposition process.
Afterward, Cu-Ni modified electrode was scanned by cyclic voltammetry (CV) method in NaOH solution to convert Cu and Ni nanoparticles to the nano-scaled CuxO-NiO film. The electrocatalytic behavior of the novel CuxO-NiO film toward glucose oxidation was studied by CV and chronoamperometry (CHA) techniques. The calibration curve of glucose was found linear in a wide range of 0.04–5.76 mM, with a low limit of detection (LOD) of 7.3 μM (S/N = 3) and high sensitivity (1.38 mA mM-1 cm-2). The sensor showed high selectivity against some usual interfering species and high stability (loss of only 6.3 % of its performance over one month). The prepared CuxO-NiO nanofilm based sensor was successfully applied for monitoring glucose in human blood serum and urine samples
Comparative study of Gamow-Teller strength distributions in the odd-odd nucleus 50V and its impact on electron capture rates in astrophysical environments
Gamow-Teller (GT) strength transitions are an ideal probe for testing nuclear
structure models. In addition to nuclear structure, GT transitions in nuclei
directly affect the early phases of Type Ia and Type-II supernovae core
collapse since the electron capture rates are partly determined by these GT
transitions. In astrophysics, GT transitions provide an important input for
model calculations and element formation during the explosive phase of a
massive star at the end of its life-time. Recent nucleosynthesis calculations
show that odd-odd and odd-A nuclei cause the largest contribution in the rate
of change of lepton-to-baryon ratio. In the present manuscript, we have
calculated the GT strength distributions and electron capture rates for odd-odd
nucleus 50V by using the pn-QRPA theory. At present 50V is the first
experimentally available odd-odd nucleus in fp-shell nuclei. We also compare
our GT strength distribution with the recently measured results of a
50V(d,2He)50Ti experiment, with the earlier work of Fuller, Fowler, and Newman
(referred to as FFN) and subsequently with the large-scale shell model
calculations. One curious finding of the paper is that the Brink's hypothesis,
usually employed in large-scale shell model calculations, is not a good
approximation to use at least in the case of 50V. SNe Ia model calculations
performed using FFN rates result in overproduction of 50Ti, and were brought to
a much acceptable value by employing shell model results. It might be
interesting to study how the composition of the ejecta using presently reported
QRPA rates compare with the observed abundances.Comment: 16 pages, 5 figure
Off-label use of direct oral anticoagulants in patients receiving surgical mechanical and bioprosthetic heart valves
This cohort study assesses direct oral anticoagulant use in patients with surgical prosthetic heart valves in the United States and evaluates differences in preoperative and postoperative profiles in patients discharged while receiving direct oral anticoagulant vs warfarin
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