Locality estimation of parallel algorithm for distributed memory computers

Locality is an algorithm characteristic describing a usage level of fast access memory. For example, in case of distributed memory computers we focus on memory of each computational node. To achieve the high performance of algorithm implementation one should choose the best possible locality option. Studying the parallel algorithm locality is to estimate the number and volume of data communications. In this work, we formulate and prove the statements for computers with distributed memory that allow us to estimate the asymptotic volume of data communication operations. These estimation results are useful while comparing alternative versions of parallel algorithms during data communication cost analysis.

Generalized blocked Floyd – Warshall algorithm

One of the most commonly used on practice all-pairs shortest paths algorithms on weighted graphs is Floyd – Warshall algorithm. Blocked version serves as a basis for obtaining effective parallel algorithms to be implemented on multicore central processing units, on computers with distributed memory, on graphics processing units (GPU). Increasing computation granularity in blocked versions of algorithm leads to a more efficient usage of caches and more efficient organization of parallel computations. In this paper we introduce generalization of blocked Floyd – Warshall algorithm. Computing blocks execution order was reorganized in such a way that array elements which participate in communication operations, both reading and writing, are pushed out of fast-access memory less often. This means that in GPU implementation slow global memory is used less often, compared with the original blocked algorithm.

Node Authentication Using NTRU Algorithm in Opportunistic Network

The demand for using wireless paradigms for performing various information and communication operations has been exploded. The opportunistic networks is a special type of delay tolerant networks proposed to operate in an emergency manner to facilitate mobile connectivity between the nodes when there is no connectivity. These emergencies are caused either by human-made or natural disasters. Opportunistic Networks depend on mobile phones and other mobile devices that carry wireless technology. This paper is an attempt to expand the opportunistic network through the authentication nodes. We propose an NTRU algorithm for node authentication in opportunistic networks .NTRU algorithm is an asymmetric post-quantum cryptosystem. This algorithm is unbreakable and robust compared to RSA and ECC cryptosystem.

Tiled parallel 2D computational processes

The algorithm implemented on a parallel computer with distributed memory has, as a rule, a tiled structure: a set of operations is divided into subsets, called tiles. One of the modern approaches to obtaining tiled versions of algorithms is a tiling transformation based on information sections of the iteration space, resulting in macro-operations (tiles). The operations of one tile are performed atomically, as one unit of calculation, and the data exchange is done by arrays. The method of construction of tiled computational processes logically organized as a two-dimensional structure for algorithms given by multidimensional loops is stated. Compared to one-dimensional structures, the use of two-dimensional structures is possible in a smaller number of cases, but it can have advantages when implementing algorithms on parallel computers with distributed memory. Among the possible advantages are the reduction of the volume of communication operations, the reduction of acceleration and deceleration of computations, potentially a greater number of computation processes and the organization of data exchange operations only within the rows or columns of processes. The results are a generalization of some aspects of the method of construction of parallel computational processes organized in a one-dimensional structure to the case of a two-dimensional structure. It is shown that under certain restrictions on the structure and length of loops, it is sufficient to perform tiling on three coordinates of a multidimensional iteration space. In the earlier theoretical studies, the parallelism of tiled computations was guaranteed in the presence of information sections in all coordinates of the iteration space, and for a simpler case of a one-dimensional structure, in two coordinates.

Effort Increasing Learning Result Of Communication Operations Calculating Methods Using Napier Bone Students Class Students In Basic Schools 12 Tebat Karai

This study aims to determine whether the use of Napier Bone Exam can improve mathematics learning outcomes in multiplication counting operations. The method in this study is a classroom action research with a collaborative form involving researchers who are also as principals, and peers of teachers.This research was conducted in class V at State SDN 12 Tebat Karai District in Kepahiang in the school year 2015/2016 with the number of students 20 people. The focus of this research is the result of mathematics learning on multiplication counting and the effectiveness of napier bone wear. Action Research This class uses two cycles. Each cycle consists of four steps: planning, action, observation and reflection.The results showed an increase, this is evidenced by the results obtained in cycle I and cycle II with SK / KD as well as different indicators in the category of very good. By looking at the results of this study can be concluded that this research is able to answer the purpose of research that the use of napier bone skeleton can improve the results of mathematics learning on the multiplication counts class V students in SDN 12 TebatKaraiKepahiang Regency 2015/2016. Other data relating to research and student work as attached. Finally, researchers suggest to all teachers to be creative in presenting lessons, especially in using props and media that are interesting and varied so that it can bring students in a fun learning process and thorough completion of student learning outcomes can be achieved.

Studying Photonics Crystal Cavities by Design and Simulation of a 1 to 8 Optical Demultiplexer

In this paper we are going to design and simulating a 1 to 8 demultiplexer based on Photonic Crystal (PhC) that where in wavelengths was guided to her coupled cavity and after that our Intended output. This structure is good Selection to communication operations that their wavelengths are around 1550nm. High Q factor, high transmission speed and low crosstalk between wavelengths are the advantages of this structure. The area of this structure is $560\,{\rm{ \mu }}{{\rm{m}}^{\rm{2}}}$. The wavelengths was selected to this work are 1602.1 nm, 1598.3 nm, 1595.2 nm, 1591.8 nm, 1588.6 nm, 1585.4 nm, 1582.4 nm, 1579.6 nm. In this paper we are going to prepare the crosstalk between outputs and our main goal is giving low crosstalk between outputs.