移动进程的蛰伏性及空间逻辑

界程逻辑(Ambient Logic)定义了一个示范性的空间逻辑来描述移动界程演算中移动进程的空间性质.然而在某些移动计算系统中,界程逻辑对移动进程空间性质的描述粒度是不够的.分析移动进程的蛰伏性质,用蛰伏和活跃来描述移动进程的存在状态,由此给出一种界程逻辑的扩展,称为状态空间逻辑.该逻辑能够描述移动进程的蛰伏性,进而更细粒度地刻画进程空间性质,且其在移动界程演算上的满足性是可判定的.同时还给出了状态空间逻辑公式的形式解释和蛰伏空间公式的逻辑推导规则.     

Computation of unique optimal ambients and optimal contrast sets of colours for cathode ray tubes

An algorithmic scheme named COLSET was recently developed which aims at computing ergonomically optimal colours and ambients for colour CRT work. However, the procedure does not necessarily produce the globally best solution. If only locally optimal estimates were to be obtained, then repeated application of COLSET might result in different guidelines for both colours and ambients. A simulation study, involving several replicated estimations, is reported here to assess this stability or uniqueness issue. The results indicate that with three to five replications there is reasonable certainty that globally best estimates will be found.     

Interaction in Time and Space

Distributed π-calculus and ambient calculus are extended with timers which may trigger timeout recovery processes. Timers provide a useful notion of relative time with respect to the interaction in a distributed system. The rather flat notion of space in timed distributed π-calculus is improved by considering a hierarchical representation of space in timed mobile ambients. Some basic results are proven, making sound both formal approaches. An easily understood example is used for both extensions, showing how it is possible to describe a non-monotonic behaviour and use a decentralized control to coordinate the interacting components in time and space.     

高纯氮气退火处理对铁钝化多孔硅形貌的影响

退火处理对复合薄膜的形貌和结构都将产生较大的影响,对由水热腐蚀技术制得的铁钝化多孔硅进行高纯氮气(99.999 9%)下900℃退火3 h,利用扫描电镜(SEM)、XRD等分析手段对比研究了铁钝化多孔硅在退火前与退火后的结构变化特点.发现在微米层次上,退火后的多孔硅样品基本保持了退火前样品表面的规则阵列排布形式;在纳米层次上,退火后样品表面的硅柱仍呈多孔状,但孔壁的硅晶粒长大,平均晶粒尺寸由退火前的5 nm长大为退火后的17.2 nm.     

Applying a testing approach to the Calculus of Fair Ambients

We apply a testing approach to the Calculus of Fair Ambients and investigate the resulting testing equivalence. We prove that variant conditions on its definition do not change its discriminating power, and it is congruent on finite processes. On a proper subset of processes, open bisimilarity is strictly included in testing equivalence. It is also proved that the translation from Pi-Calculus to Fair Ambients is fully abstract with respect to testing equivalence.     

Splitting Mobility and Communication in Boxed Ambients

Stemming from our previous work on BACI, a boxed ambient calculus with communication in- terfaces, we define a new calculus that further enhances communication mechanisms and mobility control by introducing multiple communication ports, access control lists, and port hiding.The development of the calculus is mainly focused on three objectives: separation of concerns between mobility and communication, fine-grained controls, and locality. Communication primi- tives use ports to establish communication channels between ambients, while ambient names are only used for mobility. In order to achieve a better control over mobility, the calculus includes co-capabilities à la Safe Ambients, but with the addition of access control lists. These lists contain the names of the ambients that are allowed to enter or exit the ambient with that co-capability.The resulting calculus not only provides more flexibility and expressiveness than Boxed Ambients, but also enables simpler implementations using more powerful constructs for communication and mobility. We establish the basic meta-theory of the calculus by providing rules for type safety and showing that typing is preserved during execution.     

Predicate μ-Calculus for Mobile Ambients

Ambient logics have been proposed to describe properties for mobile agents which may evolve over time as well as space. This paper takes a predicate-based approach to extending an ambient logic with recursion, yielding a predicate μ-calculus in which fixpoint formulas are formed using predicate variables. An algorithm is developed for model checking finite-control mobile ambients against formulas of the logic, providing the first decidability result for model checking a spatial logic with recursion.     

Translating Mobile Ambients into P Systems

We present a translation of the mobile ambients without communication and replication into P systems with mobile membranes. We introduce a set of developmental rules over membranes, and describe the correspondence between the behaviour of an ambient and the evolution of its translated membrane system. We give an operational correspondence result between the mobile ambients and P systems.