IEEE Trans Cybern. 2021 Jan;51(1):438-450. doi: 10.1109/TCYB.2020.3003060. Epub 2020 Dec 22.
Tissue P systems with promoters provide nondeterministic parallel bioinspired devices that evolve by the interchange of objects between regions, determined by the existence of some special objects called promoters. However, in cellular biology, the movement of molecules across a membrane is transported from high to low concentration. Inspired by this biological fact, in this article, an interesting type of tissue P systems, called monodirectional tissue P systems with promoters, where communication happens between two regions only in one direction, is considered. Results show that finite sets of numbers are produced by such P systems with one cell, using any length of symport rules or with any number of cells, using a maximal length 1 of symport rules, and working in the maximally parallel mode. Monodirectional tissue P systems are Turing universal with two cells, a maximal length 2, and at most one promoter for each symport rule, and working in the maximally parallel mode or with three cells, a maximal length 1, and at most one promoter for each symport rule, and working in the flat maximally parallel mode. We also prove that monodirectional tissue P systems with two cells, a maximal length 1, and at most one promoter for each symport rule (under certain restrictive conditions) working in the flat maximally parallel mode characterizes regular sets of natural numbers. Besides, the computational efficiency of monodirectional tissue P systems with promoters is analyzed when cell division rules are incorporated. Different uniform solutions to the Boolean satisfiability problem (SAT problem) are provided. These results show that with the restrictive condition of "monodirectionality," monodirectional tissue P systems with promoters are still computationally powerful. With the powerful computational power, developing membrane algorithms for monodirectional tissue P systems with promoters is potentially exploitable.
具有启动子的组织 P 系统提供了非确定性的并行生物启发式设备，这些设备通过区域之间对象的交换而进化，这是由一些特殊的对象（称为启动子）的存在决定的。然而，在细胞生物学中，分子跨膜的运动是从高浓度向低浓度运输的。受此生物学事实的启发，在本文中，考虑了一种有趣的组织 P 系统类型，称为具有启动子的单方向组织 P 系统，其中仅在一个方向上在两个区域之间发生通信。结果表明，这样的 P 系统使用一个细胞可以产生有限数量的数字集，使用任何长度的共转运规则，或者使用任意数量的细胞，使用最大长度为 1 的共转运规则，并以最大并行模式工作。具有两个细胞、最大长度 2 和每个共转运规则最多一个启动子的单方向组织 P 系统在最大并行模式或具有三个细胞、最大长度 1 和每个共转运规则最多一个启动子的最大并行模式下是图灵完备的，并且工作在最大并行模式或具有三个细胞、最大长度 1 和每个共转运规则最多一个启动子的最大并行模式下是图灵完备的，并且工作在最大并行模式或具有三个细胞、最大长度 1 和每个共转运规则最多一个启动子的最大并行模式下是图灵完备的，并且工作在最大并行模式下。我们还证明了，在某些限制条件下，工作在最大并行模式下的单方向组织 P 系统，具有两个细胞、最大长度 1 和每个共转运规则最多一个启动子（在某些限制条件下），可以刻画自然数的正则集。此外，还分析了在细胞分裂规则中加入启动子时单方向组织 P 系统的计算效率。提供了对布尔可满足性问题（SAT 问题）的不同统一解决方案。这些结果表明，在“单方向”的限制条件下，具有启动子的单方向组织 P 系统仍然具有强大的计算能力。具有强大的计算能力，为具有启动子的单方向组织 P 系统开发膜算法具有潜在的可操作性。
