scholarly journals Iterative arrays with finite inter-cell communication

2020 ◽  
Author(s):  
Martin Kutrib ◽  
Andreas Malcher
Keyword(s):  
Cellular Automata ◽  
Cell Communication ◽  
Constant Number ◽  
Computational Capacity

Abstract Iterative arrays whose internal inter-cell communication is quantitatively restricted are investigated. The quantity of communication is measured by counting the number of uses of the links between cells. In particular, iterative arrays are studied where the maximum number of communications per cell occurring in accepting computations is drastically bounded by a constant number. Additionally, the iterative arrays have to work in realtime. We study the computational capacity of such devices. For example, a result is that a strict and dense hierarchy with respect to the constant number of communications exists. Due to their very restricted communication, the question arises whether the usually studied decidability problems such as, for example, emptiness, finiteness, inclusion, or equivalence become decidable for such devices. However, it can be shown that all such decidability questions remain undecidable even if only four communications per cell are allowed. Finally, the undecidability results are shown to hold as well for one-way and two-way cellular automata having at most four communications per cell.

Opinion evolution in open community

2017 ◽  
Vol 28 (01) ◽  
pp. 1750003 ◽  
Author(s):  
Qiuhui Pan ◽  
Yao Qin ◽  
Yiqun Xu ◽  
Mengfei Tong ◽  
Mingfeng He
Keyword(s):  
Steady State ◽  
Cellular Automata ◽  
Open System ◽  
Constant Number ◽  
A Value ◽  
Dynamic Group ◽  
The People ◽  
Opinion Evolution

We consider a dynamic group composed with a constant number of people and the people will change periodically. Every member in the community owns a value of confidence — a mechanism that measures the agent’s coherence to his or her own attitude. Based on Cellular Automata, the opinions of all agents are synchronously updated. As long as the updating frequency and updating proportion are appropriate, the open system can reach a democracy-like steady state. The majority of agents in the community will hold the same opinion.

COMPUTATIONS AND DECIDABILITY OF ITERATIVE ARRAYS WITH RESTRICTED COMMUNICATION

2009 ◽  
Vol 19 (02) ◽  
pp. 247-264 ◽  
Author(s):  
MARTIN KUTRIB ◽  
ANDREAS MALCHER
Keyword(s):  
Pattern Recognition ◽  
Real Time ◽  
Cell Communication ◽  
Finite State Machines ◽  
Minimum Amount ◽  
State Machines ◽  
Constant Number ◽  
Input Tape ◽  
Linear Arrays ◽  
Finite State

Iterative arrays (IAs) are linear arrays of interconnected interacting finite state machines, where one distinguished one is equipped with a one-way read-only input tape. We investigate IAs operating in real time whose inter-cell communication is bounded by a constant number of bits not depending on the number of states. Their capabilities are considered in terms of syntactical pattern recognition. It is known [17] that such devices can recognize rather complicated sets of unary patterns with a minimum amount of communication, namely one-bit communication. Some examples are the sets {a2n | n ≥ 1}, {an2 | n ≥ 1}, and {ap | p is prime}. Here, we consider non-unary patterns and it turns out that the non-unary case is quite different. We present several real-time constructions for certain non-unary syntactical patterns. For example, the sets {anbn | n ≥ 1}, {anbncn | n ≥ 1}, {an(bn)m | n, m ≥ 1}, and {anbamb(ba)n·m | n, m ≥ 1} are recognized in real time by IAs. Moreover, it is shown that real-time one-bit IAs can, in some sense, add and multiply integer numbers. Furthermore, decidability questions of communication restricted IAs are dealt with. Due to the constructions provided, undecidability results can be derived. It turns out that emptiness is still not even semidecidable for one-bit IAs despite their restricted communication. Moreover, also the questions of finiteness, infiniteness, inclusion, and equivalence are non-semidecidable.

scholarly journals Iterative arrays with self-verifying communication cell

2020 ◽  
Author(s):  
Martin Kutrib
Keyword(s):  
Cellular Automata ◽  
Time Complexity ◽  
Input Word ◽  
Closure Properties ◽  
Multiplicative Factor ◽  
Computational Capacity ◽  
The Family ◽  
Computation Path

Abstract We study the computational capacity of self-verifying iterative arrays ($${\text {SVIA}}$$ SVIA ). A self-verifying device is a nondeterministic device whose nondeterminism is symmetric in the following sense. Each computation path can give one of the answers yes, no, or do not know. For every input word, at least one computation path must give either the answer yes or no, and the answers given must not be contradictory. It turns out that, for any time-computable time complexity, the family of languages accepted by $${\text {SVIA}}$$ SVIA s is a characterization of the so-called complementation kernel of nondeterministic iterative array languages, that is, languages accepted by such devices whose complementation is also accepted by such devices. $${\text {SVIA}}$$ SVIA s can be sped-up by any constant multiplicative factor as long as the result does not fall below realtime. We show that even realtime $${\text {SVIA}}$$ SVIA are as powerful as lineartime self-verifying cellular automata and vice versa. So they are strictly more powerful than the deterministic devices. Closure properties and various decidability problems are considered.

scholarly journals Adder with Efficient Speed and Area by Using Quantum-Dot Cellular Automata Technology

2019 ◽  
Vol 8 (S3) ◽  
pp. 109-113
Author(s):  
G. Sumana ◽  
G. Anjan Babu
Keyword(s):  
Cellular Automata ◽  
Quantum Dot ◽  
Breaking Point ◽  
Quantum Dot Cellular Automata ◽  
Computational Capacity

The lessening in transistor estimate by following field’s law made chip unpredictability with more computational capacity. The present size of the transistor needs to decrease more, which prompts nanotechnology. The quantum-dot cell automata come extremely close to nanotechnology presents one of the conceivable arrangements in defeat this physical breaking point, even though the designs with QCA technology are not a fundamental basic. In this brief by considering quantum-dot cell automata (QCA) innovation idea a greater part door based adder is outlined. The effectiveness in territory and speed by larger part entryway idea based adders are executed and contrasted with beforehand technique plans by utilizing verilog coding mimicked in Xilinx. The proposed one-piece QCA viper depends on another calculation that requires just three larger part entryways and two inverters for the QCA expansion. Novel 128-bit adders designed in QCA become accomplished.

Gap junctions in the prothoracic glands of the tobacco hornworm, Manduca sexta

1992 ◽  
Vol 50 (1) ◽  
pp. 706-707
Author(s):  
Ji-da Dai ◽  
M. Joseph Costello ◽  
Lawrence I. Gilbert
Keyword(s):  
Gap Junctions ◽  
Small Molecules ◽  
Manduca Sexta ◽  
Freeze Fracture ◽  
Cell Communication ◽  
Cellular Level ◽  
Thin Sections ◽  
Prothoracic Glands ◽  
Polyhydroxylated Steroids ◽  
Stimulation Of

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.

Plant peptide hormone signalling

2015 ◽  
Vol 58 ◽  
pp. 115-131 ◽  
Author(s):  
Ayane Motomitsu ◽  
Shinichiro Sawa ◽  
Takashi Ishida
Keyword(s):  
Communication Systems ◽  
Cell Communication ◽  
Peptide Hormone ◽  
Peptide Hormones ◽  
Target Cells ◽  
Signalling Molecules ◽  
Receptor Complexes ◽  
Environmental Responses ◽  
Plant Life Cycle ◽  
Multicellular Organisms

The ligand–receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone–receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions.

Sign in / Sign up

Export Citation Format

Share Document