scholarly journals Optimization of data allocation in hierarchical memory for blocked shortest paths algorithms

2021 ◽  
pp. 40-50
Author(s):  
A. A. Prihozhy
Keyword(s):  
Shortest Paths ◽  
Main Memory ◽  
Conflict Graph ◽  
Data Allocation ◽  
Complete Subgraph ◽  
Cache Size ◽  
First Case ◽  
The Matrix ◽  
Random Algorithm ◽  
Cache Block

This paper is devoted to the reduction of data transfer between the main memory and direct mapped cache for blocked shortest paths algorithms (BSPA), which represent data by a D[M×M] matrix of blocks. For large graphs, the cache size S = δ×M2, δ < 1 is smaller than the matrix size. The cache assigns a group of main memory blocks to a single cache block. BSPA performs multiple recalculations of a block over one or two other blocks and may access up to three blocks simultaneously. If the blocks are assigned to the same cache block, conflicts occur among the blocks, which imply active transfer of data between memory levels. The distribution of blocks on groups and the block conflict count strongly depends on the allocation and ordering of the matrix blocks in main memory. To solve the problem of optimal block allocation, the paper introduces a block conflict weighted graph and recognizes two cases of block mapping: non-conflict and minimum-conflict. In first case, it formulates an equitable color-class-size constrained coloring problem on the conflict graph and solves it by developing deterministic and random algorithms. In second case, the paper formulates a problem of weighted defective color-count constrained coloring of the conflict graph and solves it by developing a random algorithm. Experimental results show that the equitable random algorithm provides an upper bound of the cache size that is very close to the lower bound estimated over the size of a complete subgraph, and show that a non-conflict matrix allocation is possible at δ = 0.5 for M = 4 and at δ = 0.1 for M = 20. For a low cache size, the weighted defective algorithm gives the number of remaining conflicts that is up to 8.8 times less than the original BSPA gives. The proposed model and algorithms are applicable to set-associative cache as well.

Optimization of thermal conductivity in composites loaded with the solid-solid phase-change materials

2018 ◽  
Vol 25 (6) ◽  
pp. 1157-1165
Author(s):  
Taoufik Mnasri ◽  
Adel Abbessi ◽  
Rached Ben Younes ◽  
Atef Mazioud
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Spherical Inclusions ◽  
First Case ◽  
The Matrix ◽  
Composite Conductivity ◽  
First Time

AbstractThis work focuses on identifying the thermal conductivity of composites loaded with phase-change materials (PCMs). Three configurations are studied: (1) the PCMs are divided into identical spherical inclusions arranged in one plane, (2) the PCMs are inserted into the matrix as a plate on the level of the same plane of arrangement, and (3) the PCMs are divided into identical spherical inclusions arranged periodically in the whole matrix. The percentage PCM/matrix is fixed for all cases. A comparison among the various situations is made for the first time, thus providing a new idea on how to insert PCMs into composite matrices. The results show that the composite conductivity is the most important consideration in the first case, precisely when the arrangement plane is parallel with the flux and diagonal to the entry face. In the present work, we are interested in exploring the solid-solid PCMs. The PCM polyurethane and a wood matrix are particularly studied.

scholarly journals 3D MORPHOLOGICAL ANALYSIS OF COMPOSITE MATERIALS WITH AGGREGATES OF SPHERICAL INCLUSIONS

2011 ◽  
Vol 22 (1) ◽  
pp. 153 ◽  
Author(s):  
Arnaud Delarue ◽  
Dominique Jeulin
Keyword(s):  
Composite Materials ◽  
Volume Fraction ◽  
Empirical Distribution ◽  
Geodesic Distance ◽  
Shortest Paths ◽  
Morphological Properties ◽  
3D Images ◽  
Spherical Inclusions ◽  
New Information ◽  
The Matrix

Composite materials containing aggregates of spherical inclusions are studied from 3D images obtained by X-ray microtomography. Using two point statistics in different directions, and the empirical distribution of orientations of pairs of inclusions, interesting details concerning the anisotropy of the distribution of inclusions are obtained and are related to the method of construction for these materials. Some 3D morphological properties, available on the 3D images, give new information on the shape and the distribution of aggregates: tortuosity of shortest paths in the matrix, local volume fraction, geodesic distance function, local histograms of numbers of objects.

Solving Systems of Linear Algebraic Equations with the Use of an Selective Regularization

2021 ◽  
pp. 11-15
Author(s):  
Vladimir N. Lutay
Keyword(s):  
Diagonal Element ◽  
Decomposition Process ◽  
Algebraic Equations ◽  
Original Matrix ◽  
Triangular Matrices ◽  
First Case ◽  
Linear Algebraic Equations ◽  
The Matrix ◽  
Gauss Method ◽  
Scalar Products

The solution of systems of linear algebraic equations, which matrices can be poorly conditioned or singular is considered. As a solution method, the original matrix is decomposed into triangular components by Gauss or Chole-sky with an additional operation, which consists in increasing the small or zero diagonal terms of triangular matrices during the decomposition process. In the first case, the scalar products calculated during decomposition are divided into two positive numbers such that the first is greater than the second, and their sum is equal to the original one. In further operations, the first number replaces the scalar product, as a result of which the value of the diagonal term increases, and the second number is stored and used after the decomposition process is completed to correct the result of calculations. This operation increases the diagonal elements of triangular matrices and prevents the appearance of very small numbers in the Gauss method and a negative root expression in the Cholesky method. If the matrix is singular, then the calculated diagonal element is zero, and an arbitrary positive number is added to it. This allows you to complete the decomposition process and calculate the pseudo-inverse matrix using the Greville method. The results of computational experiments are presented.

scholarly journals Translation of a Coated Rigid Spherical Inclusion in an Elastic Matrix: Exact Solution, and Implications for Mechanobiology

2019 ◽  
Vol 86 (5) ◽  
Author(s):  
Xin Chen ◽  
Moxiao Li ◽  
Shaobao Liu ◽  
Fusheng Liu ◽  
Guy M. Genin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Exact Solution ◽  
Analytical Solution ◽  
Spherical Inclusion ◽  
Matrix Material ◽  
Elastic Matrix ◽  
Protein Ligands ◽  
First Case ◽  
The Matrix ◽  
Matrix Modulus

The displacement of relatively rigid beads within a relatively compliant, elastic matrix can be used to measure the mechanical properties of the matrix. For example, in mechanobiological studies, magnetic or reflective beads can be displaced with a known external force to estimate the matrix modulus. Although such beads are generally rigid compared to the matrix, the material surrounding the beads typically differs from the matrix in one or two ways. The first case, as is common in mechanobiological experimentation, is the situation in which the bead must be coated with materials such as protein ligands that enable adhesion to the matrix. These layers typically differ in stiffness relative to the matrix material. The second case, common for uncoated beads, is the situation in which the beads disrupt the structure of the hydrogel or polymer, leading to a region of enhanced or reduced stiffness in the neighborhood of the bead. To address both cases, we developed the first analytical solution of the problem of translation of a coated, rigid spherical inclusion displaced within an isotropic elastic matrix by a remotely applied force. The solution is applicable to cases of arbitrary coating stiffness and size of the coating. We conclude by discussing applications of the solution to mechanobiology.

Two OPW calculations of electronic transport properties of copper below 20 K

1977 ◽  
Vol 55 (6) ◽  
pp. 521-527 ◽  
Author(s):  
M. E. Brett ◽  
J. E. Black
Keyword(s):  
Fermi Surface ◽  
Electronic Transport ◽  
Phonon Scattering ◽  
Electronic States ◽  
Preliminary Calculation ◽  
First Case ◽  
Cone Model ◽  
The Matrix ◽  
Total Resistivity ◽  
Electron Phonon Scattering

The results of numerical calculations of the electrical and thermal lattice resistivity of copper at temperatures (T) below 20 K are presented. We have calculated the matrix element for electron–phonon scattering using two OPW electronic states and the Born – von Karman method of determining the phonon frequencies and eigenvectors. We have used the eight-cone model of the Fermi surface in which necks intersecting the Brillouin zone and the spherical belly regions are both present.The lattice electrical resistivity is calculated for two limiting cases. In the first case the resistivity is that expected when no impurities are present in the metal. In the second case the impurity resistivity is taken to dominate the lattice resistivity. We show that the T3 behaviour of lattice resistivity recently observed experimentally below 10 K can be understood as occurring when the temperature is lowered and the total resistivity moves from the lattice dominated to impurity dominated case.The results of a preliminary calculation, in which a more exact Fermi surface and 27 APW electronic states were used, are also described.

Stress Distributions During Fiber Pull-Out

1996 ◽  
Vol 63 (2) ◽  
pp. 301-306 ◽  
Author(s):  
R. Krishna Kumar ◽  
J. N. Reddy
Keyword(s):  
Stress Distribution ◽  
Axial Stress ◽  
Friction Stress ◽  
Stress Distributions ◽  
Pull Out ◽  
Reinforced Composite ◽  
First Case ◽  
The Matrix ◽  
Axial Stress Distribution ◽  
Perturbed Lagrangian

Fiber pull-out resistance is an important mechanism of energy absorption during the failure of fiber-reinforced composite materials. This paper deals with axial stress distribution in the fiber during a pull-out. The frictional constraint between the fiber and the matrix is modeled with a perturbed Lagrangian approach and Coulomb’s law of friction. Stress distribution has been determined for three cases, using the finite element method. The first case deals with the pull out of a fully embedded fiber. The second determines the stress distribution during fiber pull-out in the presence of a broken-embedded fiber. The third model attempts to solve the pull out of a coated fiber. The results for the first case compares favorably with those in existing literature. A local “pinching” effect, due to the matrix collapse behind the pulled fiber, is brought out clearly by this model. The second study indicates that the “plug” effect may not be significant in affecting the stress distribution. Lastly, the effects of coating stiffness and thickness are investigated.

scholarly journals Candida auris emergence in the Himalayan foothills: First case report from Uttarakhand, India

2020 ◽  
Author(s):  
Suneeta Meena ◽  
Ranjana Rohilla ◽  
Neelam Kaistha ◽  
Arpana Singh ◽  
Pratima Gupta
Keyword(s):  
Case Report ◽  
Tertiary Care ◽  
Multidrug Resistant ◽  
Whipple Procedure ◽  
Care Hospital ◽  
Candida Auris ◽  
Flight Mass Spectrometry ◽  
First Case ◽  
The Matrix ◽  
Head Of The Pancreas

Background and Purpose: Candida auris is a rapidly emerging fungus, which is considered globally a cause of concern for public health. This report describes the first case of C. auris fungemia from a tertiary care hospital in the hilly state of Uttarakhand in India. Case report: The patient was a 37-year-old female who underwent a Whipple procedure for the carcinoma of the head of the pancreas. She developed fever 12 days after the operation while recovering from surgery in the hospital. Blood culture yielded C. auris which was identified by the matrix-assisted laser desorption/ionization-time of flight mass spectrometry (Bruker Daltonics, Germany). The patient was successfully treated with caspofungin. Conclusion: In conclusion, C. auris is potentially multidrug resistant, resulting in nosocomial outbreaks and sporadic infections which can be potentially prevented when identified early by implementing contact precautionsBackground and Purpose: Candida auris is a rapidly emerging fungus, which is considered globally a cause of concern for public health. This report describes the first case of C. auris fungemia from a tertiary care hospital in the hilly state of Uttarakhand in India. Case report: The patient was a 37-year-old female who underwent a Whipple procedure for the carcinoma of the head of the pancreas. She developed fever 12 days after the operation while recovering from surgery in the hospital. Blood culture yielded C. auris which was identified by the matrix-assisted laser desorption/ionization-time of flight mass spectrometry (Bruker Daltonics, Germany). The patient was successfully treated with caspofungin. Conclusion: In conclusion, C. auris is potentially multidrug resistant, resulting in nosocomial outbreaks and sporadic infections which can be potentially prevented when identified early by implementing contact precautions.

scholarly journals Exploiting Data Compression for Adaptive Block Placement in Hybrid Caches

Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 240
Author(s):  
Beomjun Kim ◽  
Yongtae Kim ◽  
Prashant Nair ◽  
Seokin Hong
Keyword(s):  
Random Access ◽  
Spin Transfer Torque ◽  
Main Memory ◽  
Spin Transfer ◽  
Access Memory ◽  
Low Leakage ◽  
Block Placement ◽  
On Chip ◽  
Hybrid Caches ◽  
Cache Block

STT-RAM (Spin-Transfer Torque Random Access Memory) appears to be a viable alternative to SRAM-based on-chip caches. Due to its high density and low leakage power, STT-RAM can be used to build massive capacity last-level caches (LLC). Unfortunately, STT-RAM has a much longer write latency and a much greater write energy than SRAM. Researchers developed hybrid caches made up of SRAM and STT-RAM regions to cope with these challenges. In order to store as many write-intensive blocks in the SRAM region as possible in hybrid caches, an intelligent block placement policy is essential. This paper proposes an adaptive block placement framework for hybrid caches that incorporates metadata embedding (ADAM). When a cache block is evicted from the LLC, ADAM embeds metadata (i.e., write intensity) into the block. Metadata embedded in the cache block are then extracted and used to determine the block’s write intensity when it is fetched from main memory. Our research demonstrates that ADAM can enhance performance by 26% (on average) when compared to a baseline block placement scheme.

scholarly journals WRITING ELECTRONIC FERROMAGNETIC STATES IN A HIGH-TEMPERATURE PARAMAGNETIC NUCLEAR SPIN SYSTEM

2011 ◽  
Vol 09 (04) ◽  
pp. 1047-1056 ◽  
Author(s):  
D. O. SOARES-PINTO ◽  
J. TELES ◽  
A. M. SOUZA ◽  
E. R. DEAZEVEDO ◽  
R. S. SARTHOUR ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Mean Field ◽  
Field Approximation ◽  
Order Transition ◽  
Mean Field Approximation ◽  
Temperature Hysteresis ◽  
First Case ◽  
The Matrix ◽  
The Mean

In this paper, we use Nuclear Magnetic Resonance (NMR) to write electronic states of a ferromagnetic system into high-temperature paramagnetic nuclear spins. Through the control of phase and duration of radio frequency pulses, we set the NMR density matrix populations, and apply the technique of quantum state tomography to experimentally obtain the matrix elements of the system, from which we calculate the temperature dependence of magnetization for different magnetic fields. The effects of the variation of temperature and magnetic field over the populations can be mapped in the angles of spin rotations, carried out by the RF pulses. The experimental results are compared to the Brillouin functions of ferromagnetic ordered systems in the mean field approximation for two cases: the mean field is given by (i) B = B0 + λM and (ii) B = B0 + λM + λ′M3, where B0 is the external magnetic field, and λ, λ′ are mean field parameters. The first case exhibits second order transition, whereas the second case has first order transition with temperature hysteresis. The NMR simulations are in good agreement with the magnetic predictions.

scholarly journals First Case Report of an Unusual Fungus (Sporopachydermia lactativora) Associated with a Pulmonary Infection in a Drug Injection User

2021 ◽  
Vol 14 ◽  
pp. 2632010X2110299
Author(s):  
Hiba A Al Dallal ◽  
Siddharth Narayanan ◽  
Christopher M Jones ◽  
Shawn R Lockhart ◽  
James W Snyder
Keyword(s):  
Case Report ◽  
Treatment Options ◽  
Pathogenic Fungi ◽  
First Case ◽  
New Information ◽  
The Matrix ◽  
Potential Pathogen ◽  
Physician Awareness ◽  
History Of ◽  
Polysubstance Abuse

In contrast to a robust literature on known pathogenic fungi such as Cryptococcus and Aspergillus species that cause pulmonary infections, reports of the uncommon genus Sporopachydermia causing infections are very limited. We present the first case report describing the fungus, Sporopachydermia lactativora as a likely cause of pneumonia in a patient with a history of polysubstance abuse and injection drug use (IDU). The patient recovered following antifungal treatment. The organism was recovered from a blood culture, 3 days post collection. Although CHROMagar was of little value, only yeast-like organisms were observed on cornmeal agar. The organism was not in the matrix-assisted laser desorption/ionization—time of flight (MALDI-TOF) mass spectrometry database. Definitive identification was achieved using the ribosomal DNA (rDNA) sequence analysis by targeting the ITS1 (internal transcribed spacer 1) region. This case report is intended to promote awareness of this fungus as a potential pathogen, by providing new information that has not yet been reported in the literature, and prompts physician awareness to suspect a fungal infection when managing patients with a history of IDU as a potential source of unique environmental organisms not previously encountered, warranting more comprehensive diagnosis and treatment options.

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