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52
Computing with Membranes
 JOURNAL OF COMPUTER AND SYSTEM SCIENCES
, 1998
"... We introduce a new computability model, of a distributed parallel type, based on the notion of a membrane structure. Such a structure consists of several celllike membranes, recurrently placed inside a unique "skin" membrane. A plane representation is a Venn diagram without intersected sets and wit ..."
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Cited by 352 (4 self)
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We introduce a new computability model, of a distributed parallel type, based on the notion of a membrane structure. Such a structure consists of several celllike membranes, recurrently placed inside a unique "skin" membrane. A plane representation is a Venn diagram without intersected sets and with a unique superset. In the regions delimited by the membranes there are placed objects; the obtained construct is called a supercell. These objects are assumed to evolve: each object can be transformed in other objects, can pas through a membrane, or can disolve the membrane in which it is placed. A priority relation between evolution rules can be considered. The evolution is done in parallel for all objects able to evolve. In this way, we obtain a computing device (we call it a supercell system): start with a certain number of objects in a certain membrane and let the system evolve; if it will halt (no object can further evolve), then the computation is finished, with the result given as...
DNA Computing Based on Splicing: Universality Results
 FIRST ANNUAL PACIFIC SYMPOSIUM ON BIOCOMPUTING
, 1996
"... The paper extends some of the most recently obtained results on the computational universality of specific variants of H systems (e. g. with regular sets of rules) and proves that we can construct universal computers based on various types of H systems with a finite set of splicing rules as well as ..."
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Cited by 20 (6 self)
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The paper extends some of the most recently obtained results on the computational universality of specific variants of H systems (e. g. with regular sets of rules) and proves that we can construct universal computers based on various types of H systems with a finite set of splicing rules as well as a finite set of axioms, i. e. we show the theoretical possibility to design programmable universal DNA computers based on the splicing operation. For H systems working in the multiset style (where the numbers of copies of all available strings are counted) we elaborate how a Turing machine computing a partial recursive function can be simulated by an equivalent H system computing the same function; in that way, from a universal Turing machine we obtain a universal H system. Considering H systems as language generating devices we have to add various simple control mechanisms (checking the presence/absence of certain symbols in the spliced strings) to systems with a finite set of splicing ru...
Test Tube Distributed Systems Based on Splicing
 COMPUTERS AND AI
, 1996
"... We define a symbol processing mechanism with the components (test tubes) working as splicing schemes in the sense of T. Head and communicating by redistributing the contents of tubes (in a similar way to the separate operation of LiptonAdleman). (These systems are similar to the distributed generat ..."
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Cited by 19 (1 self)
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We define a symbol processing mechanism with the components (test tubes) working as splicing schemes in the sense of T. Head and communicating by redistributing the contents of tubes (in a similar way to the separate operation of LiptonAdleman). (These systems are similar to the distributed generative mechanisms called Parallel Communicating Grammar Systems.) Systems with finite initial contents of tubes and finite sets of splicing rules associated to each component are computationally complete, they characterize the family of recursively enumerable languages. The existence of universal test tube distributed systems is obtained on this basis, hence the theoretical proof of the possibility to design universal programmable computers with the structure of such a system.
Parallel Communicating Grammar Systems With Negotiation
, 1996
"... In a parallel communicating grammar system, several grammars work together, synchronously, on their own sentential forms, and communicate on request. No restriction is imposed usually about the communicated strings. We consider here two types of restrictions, as models of the negotiation process in ..."
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Cited by 12 (3 self)
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In a parallel communicating grammar system, several grammars work together, synchronously, on their own sentential forms, and communicate on request. No restriction is imposed usually about the communicated strings. We consider here two types of restrictions, as models of the negotiation process in multiagent systems: (1) conditions formulated on the transmitted strings, and (2) conditions formulated on the resulting string in the receiving components. These conditions are expressed in terms of regular languages, whose elements the mentioned strings should be. Moreover, we allow that the communicated string is a part (any one, a prefix, a maximal, a minimal one, etc.) of the string of the communicating component. We investigate these variants from the point of view of the generative capacity of the corresponding parallel communicating grammar systems. 1.
DNA Computing Based on Splicing: Universality Results
, 1997
"... First, we recall some characterizations of recursively enumerable languages by means of finite H systems with certain regulations on the splicing operation. Then, we consider a variant of the splicing operation where the splicing proceeds always in couples of steps: the two strings obtained after a ..."
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Cited by 10 (0 self)
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First, we recall some characterizations of recursively enumerable languages by means of finite H systems with certain regulations on the splicing operation. Then, we consider a variant of the splicing operation where the splicing proceeds always in couples of steps: the two strings obtained after a splicing enter immediately a second splicing (the rules used in the two steps are not prescribed). Somewhat surprising if we take into account the loose control on the performed operations, extended H systems with finite sets of axioms and of splicing rules, using this double splicing operation, can again characterize the recursively enumerable languages. Finally, we consider twotypes of distributed H systems: communicating distributed H systems and timevarying distributed H systems. For the first type of devices, we give a new proof of the recent result of [24] that (in the extended case) such systems with three components characterize the recursively enumerable languages. In what...
Further open problems in membrane computing, Brainstorming Week on Membrane Computing
 Sevilla University
, 2004
"... Abstract. A series of open problems and research topics in membrane computing are pointed out, most of them suggested by recent developments in this area. Many of these problems have several facets and branchings, and further facets and branchings can surely be found after addressing them in a more ..."
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Cited by 7 (0 self)
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Abstract. A series of open problems and research topics in membrane computing are pointed out, most of them suggested by recent developments in this area. Many of these problems have several facets and branchings, and further facets and branchings can surely be found after addressing them in a more careful manner. 1
Quorum sensing P systems
, 2006
"... This paper continues the investigation of population P systems model [F. Bernardini, M. Gheorghe, Population P systems, Journal of Universal Computer Science 10 (5) (2004) 509–539] by considering bacterium quorum sensing (QS) phenomena as the basis of the new approach. A new computational model call ..."
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Cited by 7 (4 self)
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This paper continues the investigation of population P systems model [F. Bernardini, M. Gheorghe, Population P systems, Journal of Universal Computer Science 10 (5) (2004) 509–539] by considering bacterium quorum sensing (QS) phenomena as the basis of the new approach. A new computational model called QS P system is introduced. It is proved that QS P systems are able to simulate counter machines, and hence they are equivalent in power to Turing machines. An example of a QS P system modelling the behaviour of Vibrio fischeri bacteria colonies is also presented and the emergence of the QS mechanism is illustrated.
Grammar Systems with Counting Derivation and Dynamical Priorities
, 1997
"... The paper deals with a new type of restriction considered for the cooperation protocol of grammar systems. The effect of this strategy is investigated for all modes of derivation. Some connections are made with the usual concepts of fairness [1, 6] and that introduced for grammar systems [5]. ..."
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Cited by 6 (5 self)
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The paper deals with a new type of restriction considered for the cooperation protocol of grammar systems. The effect of this strategy is investigated for all modes of derivation. Some connections are made with the usual concepts of fairness [1, 6] and that introduced for grammar systems [5].
DISTRIBUTED PROCESSING IN AUTOMATA
 INTERNATIONAL JOURNAL OF FOUNDATIONS OF COMPUTER SCIENCE
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