No abstract

PurposeSorting is a very important algorithm to solve problems in computer science. The most well-known divide and conquer sorting algorithm is quicksort. It starts with dividing the data into subarrays and finally sorting them.Design/methodology/approachIn this paper, the algorithm named Dual Parallel Partition Sorting (DPPSort) is analyzed and optimized. It consists of a partitioning algorithm named Dual Parallel Partition (DPPartition). The DPPartition is analyzed and optimized in this paper and sorted with standard sorting functions named qsort and STLSort which are quicksort, and introsort algorithms, respectively. This algorithm is run on any shared memory/multicore systems. OpenMP library which supports multiprocessing programming is developed to be compatible with C/C++ standard library function. The authors’ algorithm recursively divides an unsorted array into two halves equally in parallel with Lomuto's partitioning and merge without compare-and-swap instructions. Then, qsort/STLSort is executed in parallel while the subarray is smaller than the sorting cutoff.FindingsIn the authors’ experiments, the 4-core Intel i7-6770 with Ubuntu Linux system is implemented. DPPSort is faster than qsort and STLSort up to 6.82× and 5.88× on Uint64 random distributions, respectively.Originality/valueThe authors can improve the performance of the parallel sorting algorithm by reducing the compare-and-swap instructions in the algorithm. This concept can be used to develop related problems to increase speedup of algorithms.

The CPUs of smartphones are becoming multicore with huge RAM and storage to support a variety of multimedia applications in the near future. A MultiStack Parallel (MSP) sorting algorithm is proposed and named MSPSort to support manycore systems. It can be regarded as many threads of single-pivot interleaving block-based Hoare’s algorithm. Each thread performs compare-swap operations between left and right (stacked and interleaved) data blocks. A number of multithreading features of OpenMP and our own optimization strategies have been utilized. To simulate those smartphones, MSPSort is fine tuned and tested on four Linux systems, e.g. Intel i7-2600, Xeon X5670, AMD R7-1700 and R9-2920. Their memory configurations can be classified as either uniform or non-uniform memory access. The statistical results are satisfied compared to parallel-mode sorting algorithms of Standard Template Library, namely Balanced QuickSort and MultiWay MergeSort. Moreover, MSPSort looks promising to be developed further to improve both run time and stability.

Mobile smartphones/laptops are becoming much more powerful in terms of core count and memory capacity. Demanding games and parallel applications/algorithms can hopefully take advantages of the hardware. Our parallel MSPSort algorithm is one of those examples. However, MSPSort can be optimized and fine tuned even further to achieve its highest capabilities. To evaluate the effectiveness of MSPSort, two Linux systems are quad core ARM Cortex-A72 and 24-core AMD ThreadRipper R9-2920. It has been demonstrated that MSPSort is comparable to the well-known parallel standard template library sorting functions, i.e. Balanced QuickSort and Multiway MergeSort in various aspects such as run time and memory requirements.

This paper presents the development of web applications to support smart classroom. This research describes the web application which teachers and students can use on their mobile devices such as smartphones, tablets or laptops. The core idea behind this study is that web application motivates students to study in the classroom. The population of our research is 50 Computer Engineering students. The survey shows that the ease of using the application scores 4.40. The functions of the application score 4.44. The run time performance scores 4.32. Finally, user experience scores 4.48. and User Interface scores 4.44.