SHERZOD TURAEV - Academia.edu (original) (raw)

Papers by SHERZOD TURAEV

Malaysian Journal of Fundamental and Applied Sciences, Jul 17, 2012

A theoretical model for DNA computing using the recombination behavior of DNA molecules known as ... more A theoretical model for DNA computing using the recombination behavior of DNA molecules known as asplicing system has been introduced in 1987. Splicing systems are based on the splicing operation which, informally, cuts two strings at the specific places and attaches the prefix of the first string to the suffix of the second string and the prefix of the second string to the suffix of the first string yielding the new strings. It is known that splicing systems with finite sets of axioms and splicing rules only generate regular languages. Hence, different types of restrictions for splicing systems have been considered to increase the computational power of the languages generated. Recently, probabilistic splicing systems have been introduced where the probabilities are initially associated with the axioms, and the probabilities of the generated strings are computed from the probabilities of the initial strings. In this paper, some properties of probabilistic one-sided splicing systems, which are special types of probabilistic splicing systems, are investigated. We prove that probabilistic one-sided splicing systems can also increase the computational power of the languages generated.

In this paper we introduce splicing systems with probabilities, i.e., probabilistic splicing syst... more In this paper we introduce splicing systems with probabilities, i.e., probabilistic splicing systems, and establish basic properties of language families generated by this type of splicing systems. We show that a simple extension of splicing systems with probabilities may increase the computational power of splicing systems with finite components. N.T. Nguyen et al. (Eds.): Adv. Methods for Comput. Collective Intelligence, SCI 457, pp. 259-268.

Aip Conference Proceedings, 2014

ABSTRACT A Watson-Crick Petri net is a new formal model that enhances a Petri net with the Watson... more ABSTRACT A Watson-Crick Petri net is a new formal model that enhances a Petri net with the Watson-Crick complementary feature adapted from DNA molecules. The transitions of a Watson-Crick Petri net are labeled with pairs of symbols, and a firing sequence of transitions of the Watson-Crick Petri net is considered as successful if and only if it produces complete double stranded sequences of symmetrically related symbols according to some mode of execution termination of the firing of transitions. As an execution termination mode, we can consider the set of all reachable markings and a finite set of final markings. In this research, we investigate the fundamental properties of Watson-Crick Petri net languages with finite sets of final markings.

Software reuse is a major concern in many software development companies. It is one of the main s... more Software reuse is a major concern in many software development companies. It is one of the main strategies used to reduce the cost of software product development. Studies show that the reuse strategy is the most significant strategy in terms of effort and quality. That it could save the half of the software development effort and increase the quality of the software product. Different ways of software reuse are proposed and discussed. In this study, an evaluation model for software reuse is proposed. The model is developed in order to consider the new methods of software reuse. That developed based on the framework of develop a reusable software components through software development processes. The model is proposed in order to present the applicable methods of software reuse and to evaluate their cost.

Essentially, a Petri net controlled grammar is a context-free grammar equipped with a Petri net a... more Essentially, a Petri net controlled grammar is a context-free grammar equipped with a Petri net and a function which maps transitions of the net to rules of the grammar. The language consists of all terminal words that can be obtained by applying of a sequence of productions which is the image of an occurrence sequence of the Petri net under the function. We study the generative power of such grammars on the type of the function which can be a bijection or a coding or a weak coding and with respect to three types of admitted sets of occurrence sequences. We show that the generative power does not depend on the type of the function. Moreover, the restriction to occurrence sequences, which transform the initial marking to a marking in a given finite set of markings, leads to a more powerful class of grammars than the allowance of all occurrence sequences. Furthermore, we present some new characterizations of the family of matrix languages in terms of Petri net controlled grammars.

Aip Conference Proceedings, 2014

Sticker systems were introduced in 1998 as one of the DNA computing models by using the recombina... more Sticker systems were introduced in 1998 as one of the DNA computing models by using the recombination behavior of DNA molecules. The Watson-Crick complementary principle of DNA molecules is abstractly used in the sticker systems to perform the computation of sticker systems. In this paper, the generative power of weighted one-sided sticker systems and weighted regular sticker systems are investigated. Moreover, the relationship of the families of languages generated by these two variants of sticker systems to the Chomsky hierarchy is also presented.

Proceedings of the 10th Wseas International Conference on Software Engineering Parallel and Distributed Systems, Feb 20, 2011

In last decade, software engineering research increasingly focused on software quality enhancemen... more In last decade, software engineering research increasingly focused on software quality enhancement and evaluation, whereas most of these researches concentrate on the internal/ development perspective. However, users mainly care in the quality of performs intended functions efficiently without knowing how the software product was developed, how it is work from inside, or it is internal quality. The success of software companies is completely depends on the users' satisfaction, which they decide to use a software product or not. Therefore, in software development, strong attention must be given to the user's satisfaction. This study aims to present the quality of the software products from user's perspective. From user's viewpoint, the characteristics of the software product are discussed. Finally, a user's perspective quality model is proposed.

Theoretical Computer Science

A tree controlled grammar is specified as a pair (G,G′) where G is a context-free grammar and G′ ... more A tree controlled grammar is specified as a pair (G,G′) where G is a context-free grammar and G′ is a regular grammar. Its language consists of all terminal words with a derivation in G such that all levels of the corresponding derivation tree–except the last level–belong to L(G′). We define the nonterminal complexity Var(H) of H=(G,G′) as the sum of the numbers of nonterminals of G and G′. In Turaev et al. (2011) it is shown that tree controlled grammars H with Var(H)≤9 are sufficient to generate all recursively enumerable languages. In this paper, we improve the bound to seven. Moreover, we show that all linear and regular simple matrix languages can be generated by tree controlled grammars with a nonterminal complexity bounded by three, and we prove that this bound is optimal for the mentioned language families. Furthermore, we show that any context-free language can be generated by a tree controlled grammar (G,G′) where the number of nonterminals of G and G′ is at most four.

Aip Conference Proceedings, 2014

ABSTRACT A splicing system, one of the early theoretical models for DNA computing was introduced ... more ABSTRACT A splicing system, one of the early theoretical models for DNA computing was introduced by Head in 1987. Splicing systems are based on the splicing operation which, informally, cuts two strings of DNA molecules at the specific recognition sites and attaches the prefix of the first string to the suffix of the second string, and the prefix of the second string to the suffix of the first string, thus yielding the new strings. For a specific type of splicing systems, namely the simple splicing systems, the recognition sites are the same for both strings of DNA molecules. It is known that splicing systems with finite sets of axioms and splicing rules only generate regular languages. Hence, different types of restrictions have been considered for splicing systems in order to increase their computational power. Recently, probabilistic splicing systems have been introduced where the probabilities are initially associated with the axioms, and the probabilities of the generated strings are computed from the probabilities of the initial strings. In this paper, some properties of probabilistic simple splicing systems are investigated. We prove that probabilistic simple splicing systems can also increase the computational power of the splicing languages generated.

The software is always required to be developed and maintained a quality to the rapid progresses ... more The software is always required to be developed and maintained a quality to the rapid progresses in industry, technology, economy, and other fields. Software maintenance is considered as one of the main issues in software development life cycle that is required efforts and resources more than other phase. Studies estimated that the cost of software maintenance rapidly increased that reached the 90% of the total cost of software development life cycle. Therefore, it is considered as an economic impact in information system community. Several researches are intended to estimate and reduce the cost of this task.

Comptes Rendus De L Academie Bulgare Des Sciences Sciences Mathematiques Et Naturelles, 2014

Malaysian Journal of Fundamental and Applied Sciences, Jul 17, 2012

A theoretical model for DNA computing using the recombination behavior of DNA molecules known as ... more A theoretical model for DNA computing using the recombination behavior of DNA molecules known as asplicing system has been introduced in 1987. Splicing systems are based on the splicing operation which, informally, cuts two strings at the specific places and attaches the prefix of the first string to the suffix of the second string and the prefix of the second string to the suffix of the first string yielding the new strings. It is known that splicing systems with finite sets of axioms and splicing rules only generate regular languages. Hence, different types of restrictions for splicing systems have been considered to increase the computational power of the languages generated. Recently, probabilistic splicing systems have been introduced where the probabilities are initially associated with the axioms, and the probabilities of the generated strings are computed from the probabilities of the initial strings. In this paper, some properties of probabilistic one-sided splicing systems, which are special types of probabilistic splicing systems, are investigated. We prove that probabilistic one-sided splicing systems can also increase the computational power of the languages generated.

In this paper we introduce splicing systems with probabilities, i.e., probabilistic splicing syst... more In this paper we introduce splicing systems with probabilities, i.e., probabilistic splicing systems, and establish basic properties of language families generated by this type of splicing systems. We show that a simple extension of splicing systems with probabilities may increase the computational power of splicing systems with finite components. N.T. Nguyen et al. (Eds.): Adv. Methods for Comput. Collective Intelligence, SCI 457, pp. 259-268.

Aip Conference Proceedings, 2014

ABSTRACT A Watson-Crick Petri net is a new formal model that enhances a Petri net with the Watson... more ABSTRACT A Watson-Crick Petri net is a new formal model that enhances a Petri net with the Watson-Crick complementary feature adapted from DNA molecules. The transitions of a Watson-Crick Petri net are labeled with pairs of symbols, and a firing sequence of transitions of the Watson-Crick Petri net is considered as successful if and only if it produces complete double stranded sequences of symmetrically related symbols according to some mode of execution termination of the firing of transitions. As an execution termination mode, we can consider the set of all reachable markings and a finite set of final markings. In this research, we investigate the fundamental properties of Watson-Crick Petri net languages with finite sets of final markings.

Software reuse is a major concern in many software development companies. It is one of the main s... more Software reuse is a major concern in many software development companies. It is one of the main strategies used to reduce the cost of software product development. Studies show that the reuse strategy is the most significant strategy in terms of effort and quality. That it could save the half of the software development effort and increase the quality of the software product. Different ways of software reuse are proposed and discussed. In this study, an evaluation model for software reuse is proposed. The model is developed in order to consider the new methods of software reuse. That developed based on the framework of develop a reusable software components through software development processes. The model is proposed in order to present the applicable methods of software reuse and to evaluate their cost.

Essentially, a Petri net controlled grammar is a context-free grammar equipped with a Petri net a... more Essentially, a Petri net controlled grammar is a context-free grammar equipped with a Petri net and a function which maps transitions of the net to rules of the grammar. The language consists of all terminal words that can be obtained by applying of a sequence of productions which is the image of an occurrence sequence of the Petri net under the function. We study the generative power of such grammars on the type of the function which can be a bijection or a coding or a weak coding and with respect to three types of admitted sets of occurrence sequences. We show that the generative power does not depend on the type of the function. Moreover, the restriction to occurrence sequences, which transform the initial marking to a marking in a given finite set of markings, leads to a more powerful class of grammars than the allowance of all occurrence sequences. Furthermore, we present some new characterizations of the family of matrix languages in terms of Petri net controlled grammars.

Aip Conference Proceedings, 2014

Sticker systems were introduced in 1998 as one of the DNA computing models by using the recombina... more Sticker systems were introduced in 1998 as one of the DNA computing models by using the recombination behavior of DNA molecules. The Watson-Crick complementary principle of DNA molecules is abstractly used in the sticker systems to perform the computation of sticker systems. In this paper, the generative power of weighted one-sided sticker systems and weighted regular sticker systems are investigated. Moreover, the relationship of the families of languages generated by these two variants of sticker systems to the Chomsky hierarchy is also presented.

Proceedings of the 10th Wseas International Conference on Software Engineering Parallel and Distributed Systems, Feb 20, 2011

In last decade, software engineering research increasingly focused on software quality enhancemen... more In last decade, software engineering research increasingly focused on software quality enhancement and evaluation, whereas most of these researches concentrate on the internal/ development perspective. However, users mainly care in the quality of performs intended functions efficiently without knowing how the software product was developed, how it is work from inside, or it is internal quality. The success of software companies is completely depends on the users' satisfaction, which they decide to use a software product or not. Therefore, in software development, strong attention must be given to the user's satisfaction. This study aims to present the quality of the software products from user's perspective. From user's viewpoint, the characteristics of the software product are discussed. Finally, a user's perspective quality model is proposed.

Theoretical Computer Science

A tree controlled grammar is specified as a pair (G,G′) where G is a context-free grammar and G′ ... more A tree controlled grammar is specified as a pair (G,G′) where G is a context-free grammar and G′ is a regular grammar. Its language consists of all terminal words with a derivation in G such that all levels of the corresponding derivation tree–except the last level–belong to L(G′). We define the nonterminal complexity Var(H) of H=(G,G′) as the sum of the numbers of nonterminals of G and G′. In Turaev et al. (2011) it is shown that tree controlled grammars H with Var(H)≤9 are sufficient to generate all recursively enumerable languages. In this paper, we improve the bound to seven. Moreover, we show that all linear and regular simple matrix languages can be generated by tree controlled grammars with a nonterminal complexity bounded by three, and we prove that this bound is optimal for the mentioned language families. Furthermore, we show that any context-free language can be generated by a tree controlled grammar (G,G′) where the number of nonterminals of G and G′ is at most four.

Aip Conference Proceedings, 2014

ABSTRACT A splicing system, one of the early theoretical models for DNA computing was introduced ... more ABSTRACT A splicing system, one of the early theoretical models for DNA computing was introduced by Head in 1987. Splicing systems are based on the splicing operation which, informally, cuts two strings of DNA molecules at the specific recognition sites and attaches the prefix of the first string to the suffix of the second string, and the prefix of the second string to the suffix of the first string, thus yielding the new strings. For a specific type of splicing systems, namely the simple splicing systems, the recognition sites are the same for both strings of DNA molecules. It is known that splicing systems with finite sets of axioms and splicing rules only generate regular languages. Hence, different types of restrictions have been considered for splicing systems in order to increase their computational power. Recently, probabilistic splicing systems have been introduced where the probabilities are initially associated with the axioms, and the probabilities of the generated strings are computed from the probabilities of the initial strings. In this paper, some properties of probabilistic simple splicing systems are investigated. We prove that probabilistic simple splicing systems can also increase the computational power of the splicing languages generated.

The software is always required to be developed and maintained a quality to the rapid progresses ... more The software is always required to be developed and maintained a quality to the rapid progresses in industry, technology, economy, and other fields. Software maintenance is considered as one of the main issues in software development life cycle that is required efforts and resources more than other phase. Studies estimated that the cost of software maintenance rapidly increased that reached the 90% of the total cost of software development life cycle. Therefore, it is considered as an economic impact in information system community. Several researches are intended to estimate and reduce the cost of this task.

Comptes Rendus De L Academie Bulgare Des Sciences Sciences Mathematiques Et Naturelles, 2014