Off-line Parallel Exact String Searching

1997 ◽  
Author(s):  
Z. Galil ◽  
I. Yudkiewicz
Keyword(s):  
Parallel Algorithms ◽  
Optimal Algorithm ◽  
String Matching ◽  
Random Access ◽  
Sequential Algorithm ◽  
Matching Problem ◽  
Minimal Position ◽  
Two Factors ◽  
The One ◽  
Time Required

The string matching problem is defined as follows: given a string P0 ... Pm-1 called the pattern and a string T0 .. .Tn-1 called the text find all occurrences of the pattern in the text. The output of a string matching algorithm is a boolean array MATCH[0..n — 1] which contains a true value at each position where an occurrence of the pattern starts. Many sequential algorithms are known that solve this problem optimally, i.e., in a linear O(n) number of operations, most notable of which are the algorithms by Knuth, Morris and Pratt and by Boyer and Moore. In this chapter we limit ourselves to parallel algorithms. All algorithms considered in this chapter are for the parallel random access machine (PRAM) computation model. In the design of parallel algorithms for the various PRAM models, one tries to optimize two factors simultaneously: the number of processors used and the time required by the algorithm. The total number of operations performed, which is the time-processors product, is the measure of optimality. A parallel algorithm is called optimal if it needs the same number of operations as the fastest sequential algorithm. Hence, in the string matching problem, an algorithm is optimal if its time-processor product is linear in the length of the input strings. Apart from having an optimal algorithm the designer wishes the algorithm to be the fastest possible, where the only limit on the number of processors is the one caused by the time-processor product. The following fundamental lemma given by Brent is essential for understanding the tradeoff between time and processors : Any PRAM algoriihm of time t that consists of x elementary operations can be implemented on p processors in O(x/p + t) time. Using Brent’s lemma, any algorithm that uses a large number x of processors to run very fast can be implemented on p < x processors, with the same total work, however with an increase in time as described. A basic problem in the study of parallel algorithms for strings and arrays is finding the maximal/minimal position in an array that holds a certain value.

scholarly journals On the Comparison Complexity of the String Prefix-Matching Problem

1995 ◽  
Vol 2 (46) ◽  
Author(s):  
Dany Breslauer ◽  
Livio Colussi ◽  
Laura Toniolo
Keyword(s):  
Linear Time ◽  
String Matching ◽  
Random Access ◽  
Upper Bounds ◽  
Lower And Upper Bounds ◽  
Matching Problem ◽  
Machine Model ◽  
Worst Case ◽  
On Line ◽  
Sequential Comparison

In this paper we study the exact comparison complexity of the string<br />prefix-matching problem in the deterministic sequential comparison model<br />with equality tests. We derive almost tight lower and upper bounds on<br />the number of symbol comparisons required in the worst case by on-line<br />prefix-matching algorithms for any fixed pattern and variable text. Unlike<br />previous results on the comparison complexity of string-matching and<br />prefix-matching algorithms, our bounds are almost tight for any particular pattern.<br />We also consider the special case where the pattern and the text are the<br />same string. This problem, which we call the string self-prefix problem, is<br />similar to the pattern preprocessing step of the Knuth-Morris-Pratt string-matching<br />algorithm that is used in several comparison efficient string-matching<br />and prefix-matching algorithms, including in our new algorithm.<br />We obtain roughly tight lower and upper bounds on the number of symbol<br />comparisons required in the worst case by on-line self-prefix algorithms.<br />Our algorithms can be implemented in linear time and space in the<br />standard uniform-cost random-access-machine model.

A SPACE EFFICIENT BIT-PARALLEL ALGORITHM FOR THE MULTIPLE STRING MATCHING PROBLEM

2006 ◽  
Vol 17 (06) ◽  
pp. 1235-1251 ◽  
Author(s):  
DOMENICO CANTONE ◽  
SIMONE FARO
Keyword(s):  
Parallel Algorithms ◽  
Parallel Algorithm ◽  
Pattern Matching ◽  
String Matching ◽  
Common Factors ◽  
Building Blocks ◽  
Parallel Simulation ◽  
Direct Simulation ◽  
Matching Problem ◽  
Multiple Pattern Matching

Finite (nondeterministic) automata are very useful building blocks in the field of string matching. This is particularly true in the case of multiple pattern matching, where the use of factor-based automata can reduce substantially the number of computational steps when the patterns have large common factors. Direct simulation of nondeterministic automata can be performed very efficiently using the bit-parallelism technique, though this is not necessarily true for factor-based automata. In this paper we present an algorithm for the multiple string matching problem, based on the bit-parallel simulation of nondeterministic factor-based automata which satisfy a particular ordering condition. We also show how to enforce such condition by suitably modifying a minimal initial automaton, through equivalence preserving transformations. The resulting automaton turns out to be smaller than the corresponding maximal automata used by existing bit-parallel algorithms, as they do not take any advantage of common factors in patterns.

scholarly journals The Effect of Bioactivator Variation and Doses of Cow Dung on Quality of Coffee Exocarp Waste

el–Hayah ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 36-54
Author(s):  
Amik Krismawati ◽  
Sugiono Sugiono
Keyword(s):  
Block Design ◽  
Raw Material ◽  
Cow Dung ◽  
Cow Manure ◽  
Randomized Block Design ◽  
Two Factors ◽  
The One ◽  
Time Required ◽  
Number Of Treatment

Coffee exocarp waste produced from the harvest can be used as raw material for compost. The composting can be added with other ingredients to add organic material. Cow manure is the one ingredient that can be added to enrich organic materials. In the composting process, the time required will be longer, but the time can be accelerated by adding a bio activator. The finished compost can be applied at the plant to meet crop nutrient elements. The purpose of this research was to determine the effect of bio activator variation and doses of cow manure on the quality of compost from coffee exocarp waste. This research was conducted at compost house of Assessment Institute for Agricultural Technology (AIAT) and was held on February - April 2017. This research used factorial Randomized Block Design (RBD) with two factors; there is a variation of bio activator and doses of cow manure with three replication. Total number of treatment this research were 12 treatment, there are D1S1 = EM4 + 2 kg cow manure ; D2S1 = Moebillin + 2 kg cow manure; Petrofast + 2 kg cow manure; Decoprima + 2 kg cow manure; D1S2 = EM4 + 4 kg cow manure; D2S2 = Moebillin + 4 kg cow manure; D3S2 = Petrofast + 4 kg cow manure; D4S2 = Decoprima + 4 kg cow manure; D1S3: EM4 + 6 kg cow manure; D2S3 = Moebillin + 6 kg cow manure; D3S3 = Petrofast + 6 kg cow manure; D4S3 = Decoprima + 6 kg cow manure. The data obtained will be processed using Analysis of Variance (ANOVA). If there is a real effect, it will be continued using the BNT test (Least Significant Differences/LSD) with a 5% level. The Results showed the application of bio activator Decoprima (D4) and a dose of 6 kg cow manure (S3) could increase and shows the highest value of pH compost 6,01 (D4) and 6,06 (S3). The dose of 2 kg cow manure (S1) showed the highest compost shrinkage value (34.64%) compared to the 4 kg dose cow manure (S2) (32,22%) and 6 kg (S3) (25,68%). On the other hand, the application of bio activator variation and doses of cow manure did not significantly affect the quality of compost, including N-total (2,15% -2,60%), C-organic (21,40% -24,91%) and C/N ratio (8,81-11,15). The physical properties of the aroma compost show the smell of soil, and the color of the compost is dark brown. 

scholarly journals Fuzzy String Matching Using a Prefix Table

2020 ◽  
pp. 116-121
Author(s):  
Armen Kostanyan
Keyword(s):  
Artificial Intelligence ◽  
Finite State Machine ◽  
String Matching ◽  
Two Dimensional ◽  
Matching Problem ◽  
Machine Method ◽  
One Dimensional ◽  
Finite State ◽  
Fuzzy Pattern ◽  
The One

The string matching problem (that is, the problem of finding all occurrences of a pattern in the text) is one of the well-known problems in symbolic computations with applications in many areas of artificial intelligence. The most famous algorithms for solving it are the finite state machine method and the Knuth-Morris-Pratt algorithm (KMP). In this paper, we consider the problem of finding all occurrences of a fuzzy pattern in the text. Such a pattern is defined as a sequence of fuzzy properties of text characters. To construct a solution to this problem, we introduce a two-dimensional prefix table, which is a generalization of the one-dimensional prefix array used in the KMP algorithm.

Some Important Factors Hindering the Civic Integration of Ethnic Minorities

2021 ◽  
Vol X (2) ◽  
pp. 35-48
Author(s):  
Kakha Gabunia ◽  
◽  
Keyword(s):  
Ethnic Minorities ◽  
General System ◽  
Language Barrier ◽  
The State ◽  
Minority Languages ◽  
Local Staff ◽  
Majority Group ◽  
Two Factors ◽  
The One ◽  
Political Economic

The purpose of this article is to compile and group the list of problems that hinder the integration of ethnic minorities in the political, economic and cultural life of the country, based on research conducted by various organizations over the past 10 yearს. According to these studies, the main problem is, on the one hand, the language barrier and, on the other hand, ethnic-nationalist tendencies and stereotypes. These national mythologies and notions play one of the crucial roles in the formation of national self-identification. Ethno-nationalist tendencies are strong both in minorities and in ethnic Georgians. There are several factors behind the emergence of the ethnonationalism in Georgia First of all, it is the legacy of Soviet totalitarianism, as well as the result of the current socio-political situation. Understanding these two factors will give us a better answer as to why ethnic-nationalist sentiments are still prevailing in Georgia and why the integration of the ethnic minorities is hindered, despite being repeatedly declared by the state. The language barrier of ethnic minorities is also an important problem in the process of integration into society. The education system should make the knowledge of the state language accessible to ethnic minorities and, at the same time, ensure the protection of minority languages. To do this, the state must maximize and encourage local staff; The general system of education should ensure the upbringing of the citizen of the country and not put any group (even the majority) in an advantageous situation. show the advantage of any (even the majority) group.

scholarly journals On the Use of Magnetic RAMs in Field-Programmable Gate Arrays

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Y. Guillemenet ◽  
L. Torres ◽  
G. Sassatelli ◽  
N. Bruchon
Keyword(s):  
Power Consumption ◽  
Random Access ◽  
Switching Scheme ◽  
Fpga Design ◽  
Gate Arrays ◽  
Magnetic Switching ◽  
Field Programmable ◽  
Programmable Gate Arrays ◽  
Time Required ◽  
Magnetic Tunneling

This paper describes the integration of field-induced magnetic switching (FIMS) and thermally assisted switching (TAS) magnetic random access memories in FPGA design. The nonvolatility of the latter is achieved through the use of magnetic tunneling junctions (MTJs) in the MRAM cell. A thermally assisted switching scheme helps to reduce power consumption during write operation in comparison to the writing scheme in the FIMS-MTJ device. Moreover, the nonvolatility of such a design based on either an FIMS or a TAS writing scheme should reduce both power consumption and configuration time required at each power up of the circuit in comparison to classical SRAM-based FPGAs. A real-time reconfigurable (RTR) micro-FPGA using FIMS-MRAM or TAS-MRAM allows dynamic reconfiguration mechanisms, while featuring simple design architecture.

scholarly journals Statistical Analysis using traditional technique, Microsoft Excel and Predictive Analytic Software

10.17158/514 ◽  
2016 ◽  
Vol 19 (2) ◽  
Author(s):  
Jovelyn M. Durango ◽  
Carlito P. Yurango
Keyword(s):  
Statistical Analysis ◽  
Completion Time ◽  
Microsoft Excel ◽  
Instructional Tools ◽  
Traditional Technique ◽  
Significant Difference ◽  
Before And After ◽  
Computer Based ◽  
The One ◽  
Time Required

<p>The advent of technology has improved the way statistics is taught and learned. It is claimed that the use of computer-based instructional tools can actively explore the meaning of statistical concepts among the students, as well as enhance their learning experiences. This study aimed to compare three methods of statistical analysis namely, the traditional technique (use of the calculator), Microsoft Excel and Statistical Package for Social Sciences (SPSS) software. This investigation utilized the experimental design, specifically the One-Group Pretest – Posttest Design. There were six education students who self-assessed their attitude before and after the introduction of the use of various computation techniques and performed the statistical analysis considering also the completion time required for each process. Results of the study revealed an increase in the level of attitude among the respondents form the pretest to the posttest. Also, the cognitive level regardless of the approach was very high. However, the t-test failed to establish a significant difference in the attitude among the respondents. On the other hand, there were significant differences in both the test scores and completion time of the respondents in the three methods in favor of SPSS.</p><p> </p><p><strong>Keywords: </strong>Information technology, statistics, traditional technique, Microsoft excel, SPSS, comparative analysis, experimental research design, Davao City, Philippines. </p>

scholarly journals Intrinsic Run-time Row Hammer PUFs: Leveraging the Row Hammer Effect for Run-Time Cryptography and Improved Security

2018 ◽  
Author(s):  
Nikolaos Athanasios Anagnostopoulos ◽  
Tolga Arul ◽  
Yufan Fan ◽  
Christian Hatzfeld ◽  
André Schaller ◽  
...  
Keyword(s):  
Random Access ◽  
Physical Unclonable Functions ◽  
Generation Times ◽  
Speed Up ◽  
Run Time ◽  
Commercial Off The Shelf ◽  
Cost Efficient ◽  
Statistical Relationships ◽  
The Times ◽  
Time Required

Physical Unclonable Functions (PUFs) based on the retention times of the cells of a Dynamic Random Access Memory (DRAM) can be utilised for the implementation of cost-efficient and lightweight cryptographic protocols. However, as recent work has demonstrated, the times needed in order to generate their responses may prohibit their widespread usage. In order to address this issue, the Row Hammer PUF has been proposed by Schaller et al. [1], which leverages the row hammer effect in DRAM modules to reduce the retention times of their cells and, therefore, significantly speed up the generation times for the responses of PUFs based on these retention times. In this work, we extend the work of Schaller et al. by presenting a run-time accessible implementation of this PUF and further reducing the time required for the generation of its responses. Additionally, we also provide a more thorough investigation of the effects of temperature variations on the the Row Hammer PUF and briefly discuss potential statistical relationships between the cells used to implement it. As our results prove, the Row Hammer PUF could potentially provide an adequate level of security for Commercial Off-The-Shelf (COTS) devices, if its dependency on temperature is mitigated, and, may therefore, be commercially adopted in the near future.

scholarly journals The Political Debate on Basic Income and Welfare Reform in Spain

2018 ◽  
Vol 18 (2) ◽  
pp. 289-299 ◽  
Author(s):  
José A. Noguera
Keyword(s):  
Economic Feasibility ◽  
The Political ◽  
Basic Income ◽  
Political Debate ◽  
Stepping Stones ◽  
Welfare Policies ◽  
Radical Reform ◽  
Guarantee System ◽  
Two Factors ◽  
The One

Two factors have boosted the debate on Basic Income (BI) in Spain in recent years: on the one hand, the combination of welfare budget cuts and growing poverty rates has spread claims for a radical reform of Spanish welfare policies; on the other hand, the emergence of Podemos as a new key actor in the Spanish political arena has generated a vivid discussion on BI and income guarantee proposals. By reviewing the political debates on these proposals, I will argue that economic feasibility concerns and implementation problems are closely related to their political feasibility. Significantly, the radical rejection of ‘means-testing’ by BI defenders fails to grasp the different types and degrees of conditions that an income guarantee system may establish. The main lesson from the Spanish experience is that BI supporters should be ready to compromise and accept generous means-tested guaranteed income programs as stepping-stones.

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