String Matching Problems with Parallel Approaches An Evaluation for the Most Recent Studies

In recent years string matching plays a functional role in many application like information retrieval, gene analysis, pattern recognition, linguistics, bioinformatics etc. For understanding the functional requirements of string matching algorithms, we surveyed the real time parallel string matching patterns to handle the current trends. Primarily, in this paper, we focus on present developments of parallel string matching, and the central ideas of the algorithms and their complexities. We present the performance of the different algorithms and their effectiveness. Finally this analysis helps the researchers to develop the better techniques

A Parallel Computational Approach for String Matching- A Novel Structure with Omega Model

In r e cent day2019;s parallel string matching problem catch the attention of so many researchers because of the importance in different applications like IRS, Genome sequence, data cleaning etc.,. While it is very easily stated and many of the simple algorithms perform very well in practice, numerous works have been published on the subject and research is still very active. In this paper we propose a omega parallel computing model for parallel string matching. The algorithm is designed to work on omega model pa rallel architecture where text is divided for parallel processing and special searching at division point is required for consistent and complete searching. This algorithm reduces the number of comparisons and parallelization improves the time efficiency. Experimental results show that, on a multi - processor system, the omega model implementation of the proposed parallel string matching algorithm can reduce string matching time

High performance stride-based network payload inspection

There are two main drivers for network payload inspection: malicious data, attacks, virus detection in Network Intrusion Detection System (NIDS) and content detection in Data Leakage Prevention System (DLPS) or Copyright Infringement Detection System (CIDS). Network attacks are getting more and more prevalent. Traditional network firewalls can only check the packet header, but fail to detect attacks hidden in the packet payload. Therefore, the NIDS with Deep Packet Inspection (DPI) function has been developed and widely deployed. By checking each byte of a packet against the pattern set, which is called pattern matching, NIDS is able to detect the attack codes hidden in the payload. The pattern set is usually organized as a Deterministic Finite Automata (DFA). The processing time of DFA is proportional to the length of the input string, but the memory cost of a DFA is quite large. Meanwhile, the link bandwidth and the traffic of the Internet are rapidly increasing, the size of the attack signature database is also growing larger and larger due to the diversification of the attacks. Consequently, there is a strong demand for high performance and low storage cost NIDS. Traditional softwarebased and hardware-based pattern matching algorithms are have difficulty satisfying the processing speed requirement, thus high performance network payload inspection methods are needed to enable deep packet inspection at line rate. In this thesis, Stride Finite Automata (StriFA), a novel finite automata family to accelerate both string matching and regular expression matching, is presented. Compared with the conventional finite automata, which scan the entire traffic stream to locate malicious information, the StriFA only needs to scan samples of the traffic stream to find the suspicious information, thus increasing the matching speed and reducing memory requirements. Technologies such as instant messaging software (Skype, MSN) or BitTorrent file sharing methods, allow convenient sharing of information between managers, employees, customers, and partners. This, however, leads to two kinds of major security risks when exchanging data between different people: firstly, leakage of sensitive data from a company and, secondly, distribution of copyright infringing products in Peer to Peer (P2P) networks. Traditional DFA-based DPI solutions cannot be used for inspection of file distribution in P2P networks due to the potential out-of-order manner of the data delivery. To address this problem, a hybrid finite automaton called Skip-Stride-Neighbor Finite Automaton (S2NFA) is proposed to solve this problem. It combines benefits of the following three structures: 1) Skip-FA, which is used to solve the out-of-order data scanning problem; 2) Stride-DFA, which is introduced to reduce the memory usage of Skip-FA; 3) Neighbor-DFA which is based on the characteristics of Stride-DFA to get a low false positive rate at the additional cost of a small increase in memory consumption

Real-time Generation of Procedural Forests

The creation of 3D models for games and simulations is generally a time-consuming and labour intensive task. Forested landscapes are an important component of many large virtual environments in games and film. To create the many individual tree models required for forests requires a large numbers of artists and a great deal of time. In order to reduce modelling time procedural methods are often used. Such methods allow tree models to be created automatically and relatively quickly, albeit at potentially reduced quality. Although the process is faster than manual creation, it can still be slow and resource-intensive for large forests. The main contribution of this work is the development of an efficient procedural generation system for creating large forests. Our system uses L-Systems, a grammar based procedural technique, to generate each tree. We explore two approaches to accelerating the creation of large forests. First, we demonstrate performance improvements for the creation of individual trees in the forest, by reducing the computation required by the underlying L-Systems. Second, we reduce the memory overhead by sharing geometry between trees using a novel branch instancing approach. Test results show that our scheme significantly improves the speed of forest generation over naive methods: our system is able to generate over 100, 000 trees in approximately 2 seconds, while using a modest amount of memory. With respect to improving L-System processing, one of our methods achieves a 25% speed up over traditional methods at the cost of a small amount of additional memory, while our second method manages a 99% reduction in memory at the expense of a small amount of extra processing

Inquiries into words, constraints and contexts : Festschrift in the honour of Kimmo Koskenniemi on his 60th birthday

Peer reviewe

Behavioural patterns for the analysis of creative behaviour.

Analysing human creativity has always been a difficult undertaking. The reason for this is the vagueness of the term creativity itself. Philosophers and Researchers have tried to unveil the secrets behind creativity since centuries. Besides some principles e.g. defined by Finke, Ward, and Smith, there is no holistic understanding about term creativity and there will always be discussions between researchers of different disciplines about how creativity is achieved. Current approaches try to understand creativity through studying the creative artifact or the creative human himself. These approaches have not lead to any promising results. Instead of focussing on creativity itself, it is more promising to look at the creative process of creators. Through this, it is possible to analyse what happened during the creation of an artefact. The aim of the analysis is the identification of certain behaviours within the creative process, which lead to very creative results or in opposite hinder creativity. The gained knowledge is used for the creation of patterns, describing this specific behaviour. The analysis of the creative process is not only interesting for artists, but also for engineers, researchers, students and many others. Important target groups for this approach are schools and universities. Being able to early recognise problems in the learning curve of a student will enable a directed support, in order to improve the student's performance. Until now, the main problem for analysing the creative process of a creator is the lack of information on how an artefact was created. Most creators tend not to make many notes during their creative phase, even if there are famous exemptions like Beethoven who left behind a huge amount of notices and marked changes in his work. Hence, the challenge is the development of a powerful framework, which can cope effectively with the recording and presentation of this creative process, in order to enable detailed analyses. Modern computer technology fosters the recording of the creative process of a person. Much of today's creative work is achieved with computers and powerful software applications. Computer networks and the internet enable new ways of collaboration. The creation of a flexible, collaborative tool-set is the ideal approach for the mapping and analysis of the creative process. A novel approach, based on these ideas, was developed by the members of the Creative Technologies Research Programme at the Software Technology Research Laboratory (STRL). The central aim of the approach is the mapping of the human creativity with so-called creativity maps. A creativity map is basically transition system, which allows to store and represent the creative process as well as to hold each version of the artefact. The developed De Montfort Creativity Assistant (DMCA), is a collaborative, web-enabled state-of-the-art software framework, realising the theoretical concepts. This thesis represents a substantial contribution to the research project. The focus of the presented work lies on the analysis and the support of the creative process. Several novel techniques for the analysis of massive data sets have been developed. The presented techniques enable a domain-independent analysis and support of the creative process. This is huge improvement over previous concepts, which are highly specialised and focus on the creative artefact itself. The presented approach required the development of several novel techniques. The major contributions of the presented research are: - Behavioural Patterns Enable the description of constructs inside the creativity map. These constructs represent the creative behaviour of the creator. - Techniques for a Computer-supported Information Extraction A pattern description language enables the computer-supported information extraction from creativity maps. - Knowledge Repository Knowledge, gained through the analysis processes, is stored centrally and shared with other creators in order to stimulate further growing of knowledge. - Concepts for the Analysis and Support of the Creative Process Novel concepts allow the structured analysis and support of the creative process, regardless of the creator's domain. All developed techniques have been implemented in several tools, which aim to enrich the DMCA with the ability of a computer-supported analysis and support of the creative process

Optimal program variant generation for hybrid manycore systems

Field Programmable Gate Arrays promise to deliver superior energy efficiency in heterogeneous high performance computing, as compared to multicore CPUs and GPUs. The rate of adoption is however hampered by the relative difficulty of programming FPGAs. High-level synthesis tools such as Xilinx Vivado, Altera OpenCL or Intel's HLS address a large part of the programmability issue by synthesizing a Hardware Description Languages representation from a high-level specification of the application, given in programming languages such as OpenCL C, typically used to program CPUs and GPUs. Although HLS solutions make programming easier, they fail to also lighten the burden of optimization. Application developers must rely on expert knowledge to manually optimize their applications for each target device, meaning that traditional HLS solutions do not offer a solution to the issue of performance portability. This state of fact prompted the development of compiler frameworks such as TyTra that operate at an even higher level of abstraction that is amenable to the use of Design Space Exploration (DSE). With DSE the initial program specification can be seen as the starting location in a search-space of correct-by-construction program transformations. In TyTra the search-space is generated from the transitive-closure of term-level transformations derived from type-level transformations. Compiler frameworks such as TyTra theoretically solve the issue of performance portability by providing a way to automatically generate alternative correct program variants. They however suffer from the very practical issue that the generated space is often too large to fully explore. As a consequence, the globally optimal solution may be overlooked. In this work we provide a novel solution to issue performance portability by deriving an efficient yet effective DSE strategy for the TyTra compiler framework. We make use of categorical data types to derive categorical semantics for the formal languages that describe the terms, types, cost-performance estimates and their transformations. From these we define a category of interpretations for TyTra applications, from which we derive a DSE strategy that finds the globally optimal transformation sequence in polynomial time. This is achieved by reducing the size of the generated search space. We formally state and prove a theorem for this claim and then show that the polynomial run-time for our DSE strategy has practically negligible coefficients leading to sub-second exploration times for realistic applications

Bioinformatics

This book is divided into different research areas relevant in Bioinformatics such as biological networks, next generation sequencing, high performance computing, molecular modeling, structural bioinformatics, molecular modeling and intelligent data analysis. Each book section introduces the basic concepts and then explains its application to problems of great relevance, so both novice and expert readers can benefit from the information and research works presented here