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Prefix Scan (or simply scan) is an operator that computes all the partial sums of a vector. A scan operation results in a vector where each element is the sum of the preceding elements in the original vector up to the corresponding position. Scan is a key operation in many relevant problems like sorting, lexical analysis, string comparison, image filtering among others. Although there are libraries...
The increase in the size of the data used in natural language processing activities brings with it time and space constraints. Thus, it is important to both store and access data efficiently. This study includes experiments for storing the term-document index, which will be used in a natural language processing project, effectively in memory. For this purpose, the indexed data is compressed using...
This paper considers a method for detecting faulty elements in a linear phased array by means of set near-field probes. Using the asymptotic correspondence for two- and three-dimensional problems of the antenna theory leads to simpler mathematical models for the vertical dipoles array. A numerical study of mathematical models is based on the iterative regularization of the ill-posed problem of reconstructing...
Characterization of coherence tuning range for 2×1 photonic crystal VCSEL arrays under pulsed excitation is reported. Far field data show the coherence range is larger under pulsed conditions compared to cw operation due to reduction of resistive diode heating.
In this paper, we present a new, dynamic graph data structure, built to deliver high update rates while keeping a low memory footprint using autonomous memory management directly on the GPU. By transferring the memory management to the GPU, efficient updating of the graph structure and fast initialization times are enabled as no additional memory allocation calls or reallocation procedures are necessary...
Graph algorithms such as breadth-first search (BFS) have been gaining ever-increasing importance in the era of Big Data. However, the memory bandwidth remains the key performance bottleneck for graph processing. To address this problem, we utilize processing-in-memory (PIM), combined with non-volatile metal-oxide resistive random access memory (ReRAM), to improve the performance of both computation...
The performance of superdirective beamforming of a practical circular hydrophone array is investigated. The received signal of a 16-element circular hydrophone array with radius of 0.25m are measured in the anechoic water tank. The array manifold at the frequency of 1.11kHz is obtained. The superdirective beamforming of the circular array is designed and realized. The correctness and effectiveness...
A decoding algorithm is presented for rank-metric array codes that are based on diagonal interleaving of MDS codes. W.r.t. this metric, such array codes are known to be optimal when the underlying field is algebraically closed. It is also shown that for any list decoding radius that is smaller than the minimum rank distance, the list size can be bounded from above by an expression that is independent...
As a traditional algorithm, the string match meets a challenge with the development of the massive volume of data be-cause of gene sequencing. Surveys show that there will be a huge amount of short read segments during the process of gene sequencing and the need for a highly efficient is urgent. The BWA is an effective algorithm to deal with the short read mapping. Compared with other short read mapping...
In this paper existing map matching algorithms are combined and modified such, that the resulting algorithm is suitable for the implementation on the graphics processing unit (GPU). The map matching algorithm implemented on GPU consists of a geometrical and topological processing step, which provides high accuracy with high efficiency at the same time. An important building block of the implementation...
Buffer sharing based on pipeline parallelism is quite susceptible to inter-core communication overhead. Existing work on concurrent lock-free (CLF) queue algorithm did not take full advantage of CPU cache features to improve performance. In order to implement a fast single-producer-single-consumer (SPSC) buffer scheduling queue, this paper proposes a cache-friendly CLF queue scheduling algorithm (CFCLF),...
Data sets are often too immense to fit completely inside the computer's main memory and must instead reside on disk. If data set will be kept in main memory it will be very costly. A computer must retrieve required data and place it in internal memory to process it. Efficient data structures, like B-tree, B+ tree, are used to process large datasets. Nodes of these data structures are buffered in memory...
Dynamic vectors are among the most commonly used data structures in programming. They provide constant time random access and resizable data storage. Additionally, they provide constant time insertion (pushback) and deletion (popback) at the end of the sequence. However, in a multithreaded system, concurrent pushback and popback operations attempt to update the same shared object, creating a synchronization...
Aces4 is a parallel programming platform comprising a DSL for Computational Chemistry and its runtime system. It offers a convenient way to express parallelism together with extensive support for extremely large, possibly sparse, distributed arrays. It aids scientists in the creation of performant, scalable, massively parallel programs that can effectively take advantage of leadership class computing...
Given n horizontal segments, each associated with a color from [σ], the Categorical Segment Stabbing problem is to find the distinct K colors stabbed by a vertical line. When the end-points of the segments are distinct and lie in [1, 2n], we present an (2 + ε)n log σ + O(n)-bit index with O(K/ε) query time, where ε∈ (0, 1].When the end-points are arbitrary real numbers, a standard reduction to the...
The Suffix Tree, a crucial and versatile data structure for string analysis of large texts, is often used in pattern matching and in bioinformatics applications. The Affix Tree generalizes the Suffix Tree in that it supports full tree functionalities in both search directions. The bottleneck of Affix Trees is their space requirement for storing the data structure. Here, we discuss existing representations...
Conventional computing techniques extensively diverge over large scale computing. In order to store and operate structured data, most data scientists suggest higher dimensional arrays, especially in linearization of higher order data. However, with the developing size of datasets, the structures become prone to performance degradation for inability of maintaining expanded data velocity. Besides, reallocation...
This paper proposes a k-nearest neighbour search method inspired by grid space partitioning and the compact-trie structure. A compact trie structure, and a k-nearest neighbour search strategy are presented. Then, a k-nearest neighbour search performance comparison is carried out against two well-known methods, using one million two-dimensional spatial points and finding up to 1000 nearest neighbours...
The central notion of this paper is that of contracts for concurrency, allowing one to capture the expected atomicity of sequences of method or service calls in a concurrent program. The contracts may be either extracted automatically from the source code, or provided by developers of libraries or software modules to reflect their expected usage in a concurrent setting. We start by extending the so-far...
Modern reconfigurable computing chips, such as FPGAs, offer an unprecedented opportunity to achieving both multifunctionality and real-time responsiveness for memoryintensive embedded applications. However, how to cost-effectively synthesize application-specific hardware constructs that fully exploit memory-level parallelism remains to be a key challenge. To address this problem, we propose a new...
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