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1.
Based on the biological model of cell-to-cell communication proposed by A. Rustom et al. (Science, 2004, 303: 1007-1010), we investigate the possibilities to apply P systems with dynamic channels transporting membrane vesicles for describing processes in distributed systems.  相似文献   

2.
提出了一种基于进程代数的行为分析与检测方法.通过静态分析二进制码获得系统的控制流程图,并将其转换为进程表达式;通过消除表达式不确定性、添加并发操作以及约简归并等方式对表达式进行重写;根据并发规则消除进程表达式中的并发算子,建立分布式系统的行为检测模型,并给出行为检测的方法.理论分析和实验表明:所提出的方法降低了行为分析和检测的复杂度,在控制流分析方面具有较好的精确性.  相似文献   

3.
In this paper we discuss the potential usefulness of membrane systems as tools for modelling tumours. The approach is followed both from a macroscopic and a microscopic point of view. In the first case, one considers the tumour as a growing mass of cells, focusing on its external shape. In the second case, one descends to the microscopic level, studying molecular signalling pathways that are crucial to determine if a cell is cancerous or not. In each of these approaches we work with appropriate variants of membrane systems.  相似文献   

4.
In this paper we discuss the potential usefulness of membrane systems as tools for modelling tumours. The approach is followed both from a macroscopic and a microscopic point of view. In the first case, one considers the tumour as a growing mass of cells, focusing on its external shape. In the second case, one descends to the microscopic level, studying molecular signalling pathways that are crucial to determine if a cell is cancerous or not. In each of these approaches we work with appropriate variants of membrane systems.  相似文献   

5.
分布式无线通信系统下行功率分配策略   总被引:2,自引:0,他引:2  
为了提高分布式无线通信系统(DWCS)的频谱效率,提出了一种下行功率分配算法。该算法仅要求发送端确知大尺度信道状态信息,具有较低的复杂度,易于实现。为了对比该算法的性能,引入小尺度信道状态信息的影响,研究了发送端确知全部信道状态信息时的最优功率分配算法。仿真结果表明:所提算法极大地提高了DWCS系统的频谱效率;另外,在DWCS系统中大尺度信道状态信息是影响功率分配算法性能的主要因素,小尺度信道状态信息的作用不明显,这也正体现了DWCS的实用化优势。  相似文献   

6.
This paper presents an algorithmic way of building complex membrane systems by coupling elementary membranes. Its application seems particularly valuable in the case of asynchronous membrane systems, since the resulting membrane system remains asynchronous. The composition method is based on a handshake mechanism implemented by using antiport rules and promoters.  相似文献   

7.
数控机床分布式监控系统通信接口设计   总被引:1,自引:0,他引:1  
针对数控机床分布式监控系统,基于层次化、模块化的监控系统软件结构,设计了一种满足分布式结构的数控机床监控系统通信接口,有利于监控系统软件扩展与兼容性;同时,采用数据命令、变量ID与变量参数库组成数据表的方式,设计了一种数据传输与解析方式,实现了监控系统端与数控机床端应用层的数据快速定位、传输与解析.将所设计通信接口应用于华中DNC-11的数控机床监控系统中,通过监控数据快速、稳定、可靠的传输,实现了数控机床运行状态的监控,验证了本文设计的有效性.  相似文献   

8.
This paper presents an algorithmic way of building complex membrane systems by coupling elementary membranes. Its application seems particularly valuable in the case of asynchronous membrane systems, since the resulting membrane system remains asynchronous. The composition method is based on a handshake mechanism implemented by using antiport rules and promoters.  相似文献   

9.
PR-tree:P2P环境下一种多维数据的分布式索引结构   总被引:2,自引:0,他引:2  
提出了一种基于R-tree的更适用于P2P环境的新型多维空间索引结构———PR-tree,并且在这种新型的索引结构下进行了高维数据的查询操作.这种新型的空间索引结构有两个主要的特点:对需要查询的数据空间进行层次划分;并且对结点的插入、删除等操作具有高度的灵活性.实验表明这种新型的空间索引结构在查询效率等方面都优于其他的索引形式.  相似文献   

10.
DNA sequence design has a crucial role in successful DNA computation,which has been proved to be an NP-hard(non-deterministic polynomial-time hard) problem.In this paper,a membrane evolutionary algorithm is proposed for the DNA sequence design problem.The results of computer experiments are reported,in which the new algorithm is validated and out-performs certain known evolutionary algorithms for the DNA sequence design problem.  相似文献   

11.
 膜分离技术是20 世纪60 年代迅速崛起的一门分离新技术。导电材料多应用于特殊分离,但现在开始应用于传统分离中。导电聚合物的发现,使导电材料在制备分离膜方面获得迅速发展。导电聚合物复合膜具有导电聚合物的特性,又具有绝缘聚合物膜的柔韧性及易加工性。本文综述导电材料制备分离膜的方法、分离膜性能的改进及应用的研究进展。  相似文献   

12.
介绍了一种轮胎胶囊硫化机PLC分布式控制系统构成和监控系统软件设计,对监控系统中线程的并发性,讨论了Windows中的多线程/进程技术和在VC环境下使用WindowsAPIs编程和ActiveX控件两种串口通讯方法.  相似文献   

13.
在分布式天线分簇放置的单用户分布式无线通信系统中,为了有效地实现下行分集与复用的折中,提出了一种空时分组码(space-time block code,STBC)和垂直分层发送方案(vertical bell-labs layered space time,V-BLAST)的组合方案。在发送端根据反馈的发送相关矩阵的特征值,提出了天线选择和功率、速率分配的方案,使得系统误符号率(symbol error rate,SER)的上界最小。仿真结果表明:不同方案实际SER性能之间的关系和通过SER上界得到的关系完全一致。该方案简化了下行发送方案的设计,适合于实际应用。  相似文献   

14.
Membrane distillation technology is a new type of efficient separation technology that combines traditional distillation technology and membrane separation technology. In the study, applications of membrane distillation technology in thermal engineering and refrigerating engineering with typical energy transformation process were presented. Desorption and regeneration process of saline solution by vacuum membrane distillation was proposed on the basis of the concentration and separation properties of membrane distillation. Membrane distillation technology could be used in lithium bromide absorption refrigeration system, energy storage system, and the regeneration process of liquid desiccant solution in temperature-humidity independent control air-conditioning system. The aim of the applications was to use the low-grade energy such as waste heat, solar energy and geothermal energy adequately and to improve the available temperature difference of heat source. According to latent heat transfer and thermal conduction across the membrane in direct contact membrane distillation process, a novel membrane heat exchanger with both heat transfer and mass transfer processes was proposed. The heat exchanger could be used as the solution heat exchanger of lithium bromide absorption refrigeration system and as the special heat exchanger that recovered heat and pure water simultaneously. Some feasible process flows about the applications of membrane distillation technology to energy transformation process were listed and analyzed. Finally, future research emphases were indicated.  相似文献   

15.
This paper discusses the identification for the distributed parameter system of gas reservoirs with het erogeneous carbonate matrices. Based on the relationship between the ad hoc function and the geological feature, we set up a general model with double porous structure, clarify its effect and significance, and present a series of results of sys tem identifications, including the basic content and methods, stabilizing functional and parameter identifiability etc. Us ing the perturbation of spectra of self-adjoint operators, the identifiability of the porosities and the ad hoc coefficient is demonstrated for the general structure model. This project indicates that the identification of a distributed parameter sys tem involves parameters, boundary position and structure.  相似文献   

16.
P systems have been used many times to face with computationally difficult problems, such as NP-complete decision problems and NP-hard optimization problems. In this paper we focus our attention on another computationally intractable problem: factorization. In particular, we first propose a simple method to encode binary numbers using multisets. Then, we describe three families of P systems: the first two allow to add and to multiply two binary encoded numbers, respectively, and the third solves the factorization problem.  相似文献   

17.
P systems have been used many times to face with computationally difficult problems, such as NP-complete decision problems and NP-hard optimization problems. In this paper we focus our attention on another computationally intractable problem: factorization. In particular, we first propose a simple method to encode binary numbers using multisets. Then, we describe three families of P systems: the first two allow to add and to multiply two binary encoded numbers, respectively, and the third solves the factorization problem.  相似文献   

18.
This paper discusses the identification for the distributed parameter system of gas reservoirs with het erogeneous carbonate matrices. Based on the relationship between the ad hoc function and the geological feature, we set up a general model with double porous structure, clarify its effect and significance, and present a series of results of sys tem identifications, including the basic content and methods, stabilizing functional and parameter identifiability etc. Us ing the perturbation of spectra of self-adjoint operators, the identifiability of the porosities and the ad hoc coefficient is demonstrated for the general structure model. This project indicates that the identification of a distributed parameter sys tem involves parameters, boundary position and structure.  相似文献   

19.
Array P systems were introduced by Paun Gh. which is linking the two areas of membrane computing and picture grammars. Puzzle grammars were introduced by us for generating connected picture arrays in the two-dimensional plane, motivated by the problem of tiling the plane. On the other hand, incorporating into arrays the developmental type of generation used in the well-known biologically motivated L systems, Siromoney and Siromoney proposed a very general rectangular array generating model, called extended controlled tabled L array system (ECTLAS). In this paper we introduce two variations of the array P system, called BPG array P system and parallel array P system. The former has in the regions array objects and basic puzzle grammar rules (BPG), which are a specific kind of puzzle grammar rules. In the latter, the regions have rectangular array objects and tables of context-free rules. We examine these two types of P systems for their array generative power.  相似文献   

20.
Array P systems were introduced by Paun Gh. which is linking the two areas of membrane computing and picture grammars. Puzzle grammars were introduced by us for generating connected picture arrays in the two-dimensional plane, motivated by the problem of tiling the plane. On the other hand, incorporating into arrays the developmental type of generation used in the well-known biologically motivated L systems, Siromoney and Siromoney proposed a very general rectangular array generating model, called extended controlled tabled L array system (ECTLAS). In this paper we introduce two variations of the array P system, called BPG array P system and parallel array P system. The former has in the regions array objects and basic puzzle grammar rules (BPG), which are a specific kind of puzzle grammar rules. In the latter, the regions have rectangular array objects and tables of context-free rules. We examine these two types of P systems for their array generative power.  相似文献   

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