On implementing sparse matrix-vector multiplication on intel platform

Sparse matrix-vector multiplication, SpMV, can be a performance bottle-neck in iterative solvers and algebraic eigenvalue problems. In this thesis, we present our sparse matrix compressed chunk storage format (CCF) and SpMV CCF kernel that realizes high performance on Intel Xeon multicore and Phi processors for unstructured matrices. CCF kernel exploits the properties of CCF to enhance load balancing and SIMD efficiency. Moreover, we present the CCF auto-tuner that selects the most effective parameters and the SpMV kernel to achieve the highest possible performance that CCF can attain on a target architecture. Using 151 unstructured matrices from 38 application areas, we compare the performance of the CCF kernel to that of MKL 2018u1 SpMV CSR, MKL 2018u2 Inspector executor SpMV CSR, and Compressed Vectorization-oriented sparse Row (CVR) SpMV. We execute the kernels on a dual 24-core Skylake Xeon Platinum 8160 and a 68-core KNL Xeon Phi 7250. Executing on the dual 24-core Skylake Xeon Platinum 8160, and compared to MKL SpMV CSR, our kernel achieves superior execution throughputs for 135 matrices (89%) with an average speed improvement of 2.3x and maximum speed improvement of 27.5x. Our kernel outperforms MKL Inspector-executor SpMV CSR for 109 matrices (73%) with an average speed improvement of 1.5x and maximum speed improvement of 3.0x. Moreover, SpMV CCF outperforms SpMV CVR for 81% of the matrices with an average speed improvement of 1.8x and maximum speed improvement of 4.2x. Executing on the 68-core KNL Xeon Phi 7250, CCF achieves high average and maximum speed improvements compared to the other three kernels but for slightly smaller percentages of matrices. Lastly, we show that auto-tuning CCF parameters improves the performance for more than 50 matrices compared to the default CCF on Skylake and KNL with an average speed improvement of 1.2x

How to Accommodate Different Learning Styles in the Same Classroom: Analysis of Theories and Methods of Learning Styles

Effective learning has always been a major concern for many educational associations. It is considered one of the most important learning processes that occur in the classroom. Teachers who are interested in understanding the process of the methods of achieving effective learning look hard for the appropriate pedagogical methods that enable them to improve classroom instruction and cover all types of students in the classroom. When the effective learning is achieved in the classroom, students can benefit from what they learn not only inside classroom but also outside classrooms. To achieve effective learning as well as effective teaching, it might be necessary for teachers to become familiar with students’ methods and theories of learning (Hunt, 2011; Kumar, & Chacko, 2010). This research paper sheds light on the theories and the models of learning and teaching styles and how they play an important role in the lives of students in classroom

Characterization of double walled carbon nanotubes-polyvinylidene fluoride nanocomposites

One of the main objectives of this thesis is to disperse double-walled carbon nanotubes (DWNT) in a polyvinylidene fluoride (PVDF) matrix, and to characterize the resulting composite using electrical, thermal, and mechanical characterization techniques. DWNTs are successfully dispersed in the PVDF, and this dispersion is assessed by using optical microscopy and both scanning and transmission electron microscopy. The second objective of this study is to investigate the morphology of the PVDF after adding the carbon nanotubes. The results using the x-ray diffraction technique do not show change in the PVDF morphology with addition of DWNTs. In Differential scanning calorimetry study the results show that the melting temperature does not vary much with addition of DWNTs. An increase in the crystallization temperature and a decrease in the percent crystallinity is also observed as DWNT content increases. The electrical and mechanical properties of the composites are measured and data is used to calculate the percolation volume fraction using electrical conductivity. The results show that the percolation threshold occurs at 0.23 vol%, which is a low volume fraction further indicating a good dispersion. The critical exponent implies a three dimensional dispersion. The predicted volume fraction at percolation using the excluded volume approach indicates that the DWNTs are dispersed in small bundles of seven hexagonally closed packed tubes. The mechanical properties are done using dynamic mechanical analysis to study the effect of the nanotubes on the mechanical properties. The results show that the storage modulus is enhanced 84% by adding 4.51 vol% DWNT-PVDF below the glass transition temperature which is in a -45ðC region and it is increased by about 97% at 40ðC. Electromechanical performance of the composites is assessed by testing the actuation behavior using DC voltage. The results show no actuation for volume contents below percolation, and a measurable actuation at volume contents above percolation. Results from the different characterization techniques indicate that the DWNTs are successfully dispersed. An enhancement in electrical conductivity and dielectric constant is achieved by addition of DWNTs. At DWNT volume content above percolation, both mechanical and electromechanical enhancements are observed, as evidenced by DMA and electroactive characterization techniques

Utilization of Demolished Waste as Coarse Aggregate in Concrete

Demolishing concrete building usually produces huge amounts of remains and wastes worldwide that have promising possibilities to be utilized as coarse aggregate for new mixes of concrete. High numbers of structures around the world currently need to be removed for several reasons, such as reaching the end of the expected life, to be replaced by new investments, or were not built by the local and international standards. Maintaining or removal of such structures leads to large quantities of concrete ruins. Reusing these concrete wastes will help in saving landfill spaces in addition to more sustainability in natural resources. The objective of this study is to investigate the possibility of using old recycled concrete as coarse aggregate to make new concrete mixes, and its effect on the evolution of the compressive strength of the new concrete mixes.  Core samples for demolished concrete were tested to determine its compressive strength. The core test results can be thought of as aggregate properties for the new concrete. Then, the compressive strength and splitting tensile strength of the new recycled aggregate concrete (RAC) were determined experimentally by casting a cubes and cylinders, respectively. It was found that the evolution of compressive strength of recycled aggregate concrete is similar in behavior to the concrete with natural aggregate, except that it is about 10% lower in values. It was also seen that water absorption for recycled aggregate is noticeably higher than that for natural aggregate, and should be substituted for in the mix design

Contemporary Onlay Incisional Hernia Repair: Review Article

Background: Abdominal procedures, whether open or laparoscopic are often complicated with an incisional abdominal hernia (IH). Approximately 15% - 20 % of all laparotomies and 1% to 5% of all laparoscopic surgeries are complicated by IHs. IH is a really bad situation for doctors and patients. Dissatisfaction, long-term malfunction, and limitations of activities and unsatisfying cosmetic appearance are just a few of the side effects that patients endure as a result of IH. For doctors; it is a challenging surgical issue associated with multiple risk factors, unclear etiology and different pathological changes, affecting different patients. Management of such a variable surgical issue necessitates a good understanding of the anatomical and physiological features of the abdominal wall by the hernia surgeon beside a wide armamentarium of surgical options to deal with complex variants to repair and restore abdominal wall integrity and function, many procedures have been utilized to repair IH and to restore abdominal wall integrity. Objective: To review the feasibility and safety of the abdominal wall component release with contemporary onlay mesh fixation procedure in the treatment of incisional abdominal hernias. Conclusion: Large incisional hernias that are difficult to close in the midline might benefit from the component separation approach. Repair of incisional hernias by abdominal wall omponent separation with contemporary onlay mesh fixation results in favorable outcomes and lower recurrence rates. It gives a more durable abdominal wall repair, a more physiological repair in cases of loss of domain, an affordable financial outlay, and a low incidence of complications

The effect of educational software based on drill and practice, and gamification in developing English language skills for third-grade students in Jiza District

The article aimed to investigate the effect of using an educational software program based on Drill and Practice, and Gamification patterns in developing English language skills for third-grade students in Jiza District. Nusaiba Al Mazenia School affiliated to the Director of Education Giza District , where peopils chosen randomly. The study tool consisted of two English language tests, a reading test consisting of (16) questions, and a writing test consisting of (17) questions. The results related to the answer of the first and second questions showed a difference in the pre and post performance of the two study groups, and in favor of the post application in reading and writing skills. The results related to the answer of the third question showed that there was no statistically significant difference at the significance level (α = 0.05) in the development of students’ reading skills due to the method used (an educational program based on the gamification pattern, an educational program based on the pattern of Drill and practice), where the values of the arithmetic means are close, while the results related to the answer of the fourth question showed that there were differences at the significance level (α = 0.05) in the arithmetic mean values of students\u27 performance on the post-writing skill test, and the difference was in favor of the exercise and practice method. Among the most important recommendations is building a strategy that combines the advantages of the modes of exercise, practice, and gamification, in order to achieve the maximum benefit for teaching reading and writing skills

Parallelizing Maximal Clique Enumeration on GPUs

We present a GPU solution for exact maximal clique enumeration (MCE) that performs a search tree traversal following the Bron-Kerbosch algorithm. Prior works on parallelizing MCE on GPUs perform a breadth-first traversal of the tree, which has limited scalability because of the explosion in the number of tree nodes at deep levels. We propose to parallelize MCE on GPUs by performing depth-first traversal of independent subtrees in parallel. Since MCE suffers from high load imbalance and memory capacity requirements, we propose a worker list for dynamic load balancing, as well as partial induced subgraphs and a compact representation of excluded vertex sets to regulate memory consumption. Our evaluation shows that our GPU implementation on a single GPU outperforms the state-of-the-art parallel CPU implementation by a geometric mean of 4.9x (up to 16.7x), and scales efficiently to multiple GPUs. Our code has been open-sourced to enable further research on accelerating MCE