Improving of Quicksort Algorithm performance by sequential thread Or parallel algorithms

Quicksort is well-know algorithm used for sorting, making O(n log n) comparisons to sort a dataset of n items. Being a divide-and-conquer algorithm, it is easily modified to use parallel computing. The aim of this paper is to evaluate the performance of parallel quicksort algorithm and compare it with theoretical performance analysis. To achieve this we implement a tool to do both sequential and parallel quicksort on randomly generated arrays of different size in several runs to provide us with enough data to draw conclusions about the efficiency of using the capability of modern multicore processors together with algorithms designed to increase the speed of sorting large arrays

Worker absence and shirking : evidence from matched teacher-school data.

We utilise a unique matched teacher-school data set of absenteeism records to quantify the impact of group interaction on the absence behavior of primary and secondary teachers. To address problems of identification our study focuses on teachers who move between schools. The estimates for movers suggest that absenteeism is influenced by prevailing group absence behaviour at the school. Our finding suggests that a worker takes one more day of absenteeism if their average coworker takes 12 more days or 8 more days absenteeism per quarter for primary school and secondary school teachers, respectively. We interpret this as evidence that worker shirking is influenced by workplace absence norms

Performance Comparison of Terrestrial DVB Detection using LDPC and Turbo Codes

Last-generation and future wireless communication standards, such as DVB-T2 or DVB-NGH, are including multi-antenna transmission and reception in order to increase bandwidth efficiency and receiver robustness. The main goal is to combine diversity and spatial multiplexing in order to fully exploit the multiple-input multiple output (MIMO) channel capacity. Full-rate full-diversity (FRFD) space-time codes (STC) such as the Golden code are studied for that purpose. However, despite their larger achievable capacity, most of them present high complexity for soft detection, which hinders their combination with soft-input decoders in bit-interleaved coded modulation (BICM) schemes. This article presents a low complexity soft detection algorithm for the reception of FRFD space-frequency block codes in BICM orthogonal frequency division multiplexing (OFDM) systems and gives the performance comparision using Ldpc and Turbo codes. The proposed detector maintains a reduced and fixed complexity, avoiding the variable nature of the list sphere decoder (LSD) due to its dependence on the noise and channel conditions. Complexity and simulation based performance results are provided which show that the proposed detector performs close to the optimal log-maximum a posteriori (MAP) detection in a variety of DVB-T2 broadcasting scenarios

Schedulability of Rate Monotonic Algorithm using Improved Time Demand Analysis for Multiprocessor Environment

Real-Time Monotonic algorithm (RMA) is a widely used static priority scheduling algorithm. For application of RMA at various systems, it is essential to determine the system’s feasibility first. The various existing algorithms perform the analysis by reducing the scheduling points in a given task set. In this paper we propose a schedubility test algorithm, which reduces the number of tasks to be analyzed instead of reducing the scheduling points of a given task. This significantly reduces the number of iterations taken to compute feasibility. This algorithm can be used along with the existing algorithms to effectively reduce the high complexities encountered in processing large task sets. We also extend our algorithm to multiprocessor environment and compare number of iterations with different number of processors. This paper then compares the proposed algorithm with existing algorithm. The expected results show that the proposed algorithm performs better than the existing algorithms