DNA computing, sticker systems, and universality

We introduce the sticker systems, a computability model, which is an abstraction of the computations using the Watson-Crick complementarity as in Adleman's DNA computing experiment, [1]. Several types of sticker systems are shown to characterize (modulo a weak coding) the regular languages, hence the power of finite automata. One variant is proven to be equivalent to Turing machines. Another one is found to have a strictly intermediate power. Received: 10 October 1996 / 16 April 1997     

粒度逻辑运算下的粗糙集模型

将粗糙集理论、逻辑运算与粒度计算进行嫁接,得到了粒度逻辑运算下的粗糙集理论模型。对粒度逻辑运算下的粗糙集进行了形式化的定义,讨论并证明了相关性质。同时,讨论了知识的粗细与基于粒度逻辑运算的粗糙集之间的关系,这为进一步研究基于粒计算的知识获取和粒度推理奠定了逻辑基础。     

Discovery systems in ubiquitous computing

Ubiquitous computing introduces unique requirements for discovery technologies, which let services and devices become aware of each other without explicit human administration. Discovery lets services and devices spontaneously become aware of the availability and capability of peers on the network without explicit administration. In practice, this means that a client can discover and potentially use a device without prior knowledge of it. Although discovery is a necessary component of ubiquitous computing, the wide range of discovery systems in use today reflects the varied needs of the communities from which they originated. Some of these features are appropriate for ubiquitous computing, but others require further research and development.     

Hybridity in Embedded Computing Systems

An embedded system is a system that computer is used as a component in a larger device.In this paper,we study hybridity in embedded systems and present an interval based temporal logic to express and reason about hybrid properties of such kind of systems.     

Trends in computing with DNA

As an emerging new research area, DNA computation, or more generally biomolecular computation, extends into other fields such as nanotechnology and material design, and is developing into a new sub-discipline of science and engineering. This paper provides a brief survey of some concepts and developments in this area. In particular several approaches are described for biomolecular solutions of the satisfiability problem (using bit strands, DNA tiles and graph self-assembly). Theoretical models such as the primer splicing systems as well as the recent model of forbidding and enforcing are also described. of DNA nanostructures and nanomechanical devices as wellWe review some experimental results of self-assemblyas the design of an autonomous finite state machine.     

Enforcing stability constraints in set-membership identification of linear dynamic systems

In this paper, we consider the identification of linear systems, a priori known to be stable, from input–output data corrupted by bounded noise. By taking explicitly into account a priori information on system stability, a formal definition of the feasible parameter set for a stable linear system is provided. On the basis of a detailed analysis of the geometrical structure of the feasible set, convex relaxation techniques are presented to solve nonconvex optimization problems arising in the computation of parameter uncertainty intervals. Properties of the computed relaxed bounds are discussed. A simulated example is presented to show the effectiveness of the proposed technique.     

A logical duality for underspecified probabilistic systems

This paper establishes a Stone-type duality between specifications and infLMPs. An infLMP is a probabilistic process whose transitions satisfy super-additivity instead of additivity. Interestingly, its simple structure can encode a mix of probabilistic and non-deterministic behavior, which, as we show, is strongly related to another well-known such model: probabilistic automata. Our duality puts in relation the category of infLMPs and a category of abstract representations of them based on properties only. We exhibit a Galois connection between these categories and show that we have an adjunct pair of functors when restricted to LMPs only. Our duality also shows that an infLMP can be considered as a demonic representative of a system’s information. Moreover, it carries forward a view where states are less important, and events, or properties, become the main characters, as it should be in probability theory. Along the way, we show that bisimulation and simulation are naturally interpreted in this setting, and we exhibit the interesting relationship between infLMPs and the usual probabilistic modal logics. This paper is an extended version of a Concur ’09 paper [13]; in particular, the comparison of infLMPs with probabilistic automata and the Galois connection are new.     

混合值逻辑控制系统的状态空间方法

对于混合值逻辑控制系统,提出确定一个正则子空间的补空间的充分必要条件.对于正则子空间已有的判别 准则,给出新的证明,并提出构造补空间的新方法.对于子空间,设计计算其友好子空间的新算法,引入没有正则性假 设的不变子空间的概念,获得判别不变子空间的一系列充分必要条件.     

Mythical systems: mathematic and logical theory

The process of elaboration of the symbolic universe leads to exciting insights regarding the search for human emotional security. The symbols end up as explanatory axes of universal reality and on them are constructed myths that form a superstructure for belief systems. Human society is a multi-level system with a material structure (society), an ideological superstructure (belief systems, values, etc.) and a super superstructure with two parts: mythical (origin and justification) and utopic (final goal). All mythical belief systems have a numinous-religious nature.     

Enforcing QoS in scientific workflow systems enacted over Cloud infrastructures

The ability to support Quality of Service (QoS) constraints is an important requirement in some scientific applications. With the increasing use of Cloud computing infrastructures, where access to resources is shared, dynamic and provisioned on-demand, identifying how QoS constraints can be supported becomes an important challenge. However, access to dedicated resources is often not possible in existing Cloud deployments and limited QoS guarantees are provided by many commercial providers (often restricted to error rate and availability, rather than particular QoS metrics such as latency or access time). We propose a workflow system architecture which enforces QoS for the simultaneous execution of multiple scientific workflows over a shared infrastructure (such as a Cloud environment). Our approach involves multiple pipeline workflow instances, with each instance having its own QoS requirements. These workflows are composed of a number of stages, with each stage being mapped to one or more physical resources. A stage involves a combination of data access, computation and data transfer capability. A token bucket-based data throttling framework is embedded into the workflow system architecture. Each workflow instance stage regulates the amount of data that is injected into the shared resources, allowing for bursts of data to be injected while at the same time providing isolation of workflow streams. We demonstrate our approach by using the Montage workflow, and develop a Reference net model of the workflow.     

Task assignment in heterogeneous computing systems

The problem of task assignment in heterogeneous computing systems has been studied for many years with many variations. We consider the version in which communicating tasks are to be assigned to heterogeneous processors with identical communication links to minimize the sum of the total execution and communication costs. Our contributions are three fold: a task clustering method which takes the execution times of the tasks into account; two metrics to determine the order in which tasks are assigned to the processors; a refinement heuristic which improves a given assignment. We use these three methods to obtain a family of task assignment algorithms including multilevel ones that apply clustering and refinement heuristics repeatedly. We have implemented eight existing algorithms to test the proposed methods. Our refinement algorithm improves the solutions of the existing algorithms by up to 15% and the proposed algorithms obtain better solutions than these refined solutions.     

Continuous interaction in future computing systems

The latest developments in human computer interfaces aim at greater ease of use, and the exploitation of human communication and interaction skills typical of non-computerised environments. This kind of interaction is continuous rather than purely discrete. Continuous interaction implies a tighter coupling between system and user, and raises complicated synchronisation issues where real-time requirements and intrinsic variation of human behaviour play an essential role. In this paper, we propose a human centred layered reference model to reduce the design complexity of systems exhibiting continuous interaction. In the context of the layered model, we discuss the role that formal modelling can play in the design of these systems.

     

Cost minimization in utility computing systems

Utility computing is a form of computer service whereby the company providing the service charges the users for using the system resources. In this paper, we present system‐optimal and user‐optimal price‐based job allocation schemes for utility computing systems whose objective is to minimize the cost for the users. The system‐optimal scheme provides an allocation of jobs to the computing resources that minimizes the overall cost for executing all the jobs in the system. The user‐optimal scheme provides an allocation that minimizes the cost for individual users in the system for providing fairness. The system‐optimal scheme is formulated as a constraint minimization problem, and the user‐optimal scheme is formulated as a non‐cooperative game. The prices charged by the computing resource owners for executing the users jobs are obtained using a pricing model based on a non‐cooperative bargaining game theory framework. The performance of the studied job allocation schemes is evaluated using simulations with various system loads and configurations. Copyright © 2012 John Wiley & Sons, Ltd.     

DNA计算中的信息安全技术

DNA计算是一种模拟生物分子的结构并借助于分子生物技术进行计算的新模式。它引入了崭新的数据结构和计算方法,为解决NP完全问题提供了全新的途径。由于DNA计算具有信息处理的高并行性、低能耗及高存储密度等优点,对传统的基于计算安全的密码体系提出了挑战。DNA密码便是近年来伴随着DNA计算的研究而出现的密码学新领域。用DNA分子作为信息载体,以实现数据隐藏、认证、加密等安全技术。在简要回顾DNA计算原理的基础上,详细分析了基于DNA的一次一密方案以及Boneh用DNA计算机破解DES的方法;最后探讨在DNA计算中的信息安全技术。     

Task assignment in distributed computing systems

The problem is addressed of assigning a task with a precedence constraint to a distributed computing system. Task turnaround time with regard to communication overhead and idle time is adopted to measure the performance of task assignment. The assignment of the module is determined as is the sequence of message transmission to balance the processor load and reduce communication overhead. The search for the optimal task assignment with a precedence constraint is known to be NP-complete (Garey et al. 1979) in the strong sense. A heuristic algorithm with polynomial time complexity is then proposed in order to solve the task-assignment problem effectively. Experimental results show that the proposed approach produces a near-optimal or even optimal task assignment.