一种基于模块单子语义的动态程序切片方法

提出一种基于程序模块单子语义的新动态切片方法--模块单子动态切片.首先通过单子转换器,将切片这一类计算抽象成独立于具体语言的实体：切片单子转换器.然后,将该切片转换器作为模块加载到实际程序中,并给出相应的模块单子动态切片算法.据此,可直接在抽象语法结构上计算动态切片,不必记录程序执行历史;相应单子切片器也无需显式地构造诸如依赖图的中间结构.这种模块化抽象机制使得文中的动态切片算法具有很强的可扩展性和重用性.     

A Monadic Semantics for Core Curry

We give a deterministic, big-step operational semantics for the essential core of the Curry language, including higher-order functions, call-by-need evaluation, non-determinism, narrowing, and residuation. The semantics is structured in modular monadic style, and is presented in the form of an executable interpreter written in Haskell. It uses monadic formulations of state, non-determinism, and resumption-based concurrency.     

A Formal Semantics for DAI Language NUML

1IntroductionAsE.H.Durfeestatesin[1]:Artificia1Inte1ligence(AI)hasemphasizedbuilding"stand-alonesystems"thatcansolveproblemswithminimalhelpfromothersystems(computerorman).Thesesystemshavetraditionallybeenbrittle,inthesensethattheyfailmiser-ablywhenpresentedwithproblemsevens1ightlyoutsideoftheir1imitedrangeofexpertise...Amorepowerful,extensiblestrategyforovercomingtheinherentboundsofintelligencepresentinanyfilliteAI(ornaturaI)systemistoputsysteminasocietyofsystems,sothatitcandrawonadiversec…     

A Modular Framework for Fast Prototyping of Cooperative Unmanned Aerial Vehicle

Unmanned Aerial Vehicles (UAVs) are gaining increasing interest thanks to their flexibility and versatility. However, these systems are very complex and a good simulation platform is needed. In this paper, a new Framework for simulation and fast prototyping of UAV control laws is presented. The Framework exploits the high realism of the simulations carried out in a three-dimensional virtual environment with the easiness of use of development systems such as Matlab? for fast prototyping of control systems. Then a novel method that exploits the benefits of Model Predictive Control (MPC) for cooperative scenarios is introduced. The obtained results show good performances of MPC in solving the formation problem of unmanned aerial vehicles; finding an optimal solution and taking into account different constraints. The developed framework allows also to easily change from simulated agent to real?one.     

A Formal Semantics for the SmartFrog Configuration Language

System configuration languages are now widely used to drive the deployment and evolution of large computing infrastructures. Most such languages are highly informal, making it difficult to reason about configurations, and introducing an important source of failure. We claim that a more rigorous approach to the development and specification of these languages will help to avoid these difficulties and bring a number of additional benefits. In order to test this claim, we present a formal semantics for the core of the SmartFrog configuration language. We demonstrate how this can be used to prove important properties such as termination of the compilation process. To show that this also contributes to the practical development of clear and correct compilers, we present three independent implementations, and verify their equivalence with each other, and with the semantics. Supported by an extended example from a real configuration scenario, we demonstrate how the process of developing the semantics has improved understanding of the language, highlighted problem areas, and suggested alternative interpretations. This leads us to advocate this approach for the future development of practical configuration languages.     

IOTA: A Modular Programming System

A highly interactive programming system is presented which supports hierarchical and modular program development with abstraction mechanisms. By taking advantage of abstraction mechanisms, the system provides a "truly modular" environment, in which modules are constructed, debugged, verified, and compiled in a module-by-module fashion. Such an environment naturally requires system management of the information concerning ongoing program development, in the form of module databases. As a result, further problems arise as to how to modify the information in efficient and consistent ways. This paper discusses design objectives for modular programming systems by focusing on such issues as information management, interactive construction and modification of modules, separate processing, specification and verification, and supports for cooperative program development.     

Discovering Document Semantics QBYS: A System for Querying the WWW by Semantics

This paper describes our research into a query-by-semantics approach to searching the World Wide Web. This research extends existing work, which had focused on a query-by-structure approach for the Web. We present a system that allows users to request documents containing not only specific content information, but also to specify that documents be of a certain type. The system captures and utilizes structure information as well as content during a distributed query of the Web. The system also allows the user the option of creating their own document types by providing the system with example documents. In addition, although the system still gives users the option of dynamically querying the web, the incorporation of a document database has improved the response time involved in the search process. Based on extensive testing and validation presented herein, it is clear that a system that incorporates structure and document semantic information into the query process can significantly improve search results over the standard keyword search.     

JAPE: A Prototyping System for Collaborative Virtual Environments

We present JAPE, a flexible prototyping system to support the design of a new advanced collaborative virtual environment. We describe the utilization of different hard- and software components to quickly build a flexible, yet powerful test bed for application and algorithm development. These components include a 3-D rendering toolkit, live video acquisition, speech transmission, and the control of tracking and interaction devices. To facilitate the simultaneous design of applications and algorithms that take advantage of unique features of new collaborative virtual environments, we provide the developer with a flexible prototyping toolkit which emulates the functionality of the final system. The applicability of JAPE is demonstrated with several prototype applications and algorithms.     

A Semantics for Static Type Inference in a Nondeterministic Language

Plotkin used the models of reduction in order to obtain a semantic characterization of static type inference in the pure λ-calculus. Here we apply these models to the study of a nondeterministic language, obtaining results analogous to Plotkin′s.     

VOQL*: A Visual Object Query Language With Inductively Defined Formal Semantics

The visual object query language (VOQL) recently proposed for object databases has been successful in visualizing path expressions and set-related conditions, and providing formal semantics. However, VOQL has several problems. Due to unrealistic assumptions, only set-related conditions can be represented in VOQL. Due to lack of the explicit language construct for the notion of variables, queries are often awkward and less intuitive.In this paper, we propose VOQL^*, which extends VOQL to remove these drawbacks. We introduce the notion of visual variables and refine the syntax and semantics of VOQL based on visual variables. We carefully design the language constructs of VOQL^*to reflect the syntax of OOPC, so that the constructs such as visual variables, visual elements, simple terms, structured terms,basic formulas , formulas, and query expressions in VOQL^*are hierarchically and inductively constructed as those of OOPC. Most important, we formally define the semantics of each language construct of VOQL^*by induction using OOPC. Because of the well-defined syntax and semantics, queries in VOQL^*are clear, concise, and intuitive. We also provide an effective procedure to translate queries in VOQL^*into those in OOPC. We believe that VOQL^*is the first visual query language with the well-defined syntax reflecting the syntactic structure of logic and semantics formally defined by induction.     

FORTRAN M - A Language for Modular Parallel Programming

FORTRAN M is a small set of extensions to FORTRAN 77 that supports a modular approach to the design of message-passing programs. It has the following features. (1) Modularity. Programs are constructed by using explicitly declared communication channels to plug together program modules called processes. A process can encapsulate common data, subprocesses, and internal communication. (2) Safety. Operations on channels are restricted so as to guarantee deterministic execution, even in dynamic computations that create and delete processes and channels. Channels are typed, so a compiler can check for correct usage. (3) Architecture Independence. The mapping of processes to processors can be specified with respect to a virtual computer with size and shape different from that of the target computer. Mapping is specified by annotations that influence performance but not correctness. (4) Efficiency. FORTRAN M can be compiled efficiently for uniprocessors, shared-memory computers, distributed-memory computers, and networks of workstations. Because message passing is incorporated into the language, a compiler can optimize communication as well as computation.     

一种新的基于中间语义的跨语言信息检索模型

目前的跨语言信息检索能够使用的方法有四种查询词翻译的方法、文档翻译的方法、中间语言翻译方法和非翻译的方法。该文对这四种方法进行了简要介绍,提出它们的优缺点,并且提出了一种新的非翻译的方法——基于中间语义的方法。我们对提出来的方法进行了TREC跨语言语料库的试验,并且与单语言的信息检索模型进行了比较。试验证明我们的方法具有很好的性能和健壮性。     

使用延时演算的时间化RSL的指称语义

使用扩展的持续时间演算(EDC)模型,给出了时间化的RAISE描述语言(RSL)的一个子集的指称语义.在扩展的持续时间演算模型中加入了一些新的特征,并探究了它们的代数定律.这些定律在形式化实时程序和验证实时性质中起着重要作用.最后还给出了时间化RSL的一些代数定律.这些定律可以从其指称语义证明,并用于程序的转化和优化.     

A Prolog Framework for the Rapid Prototyping of Language Processors with Attribute Grammars

In this paper, we describe PAG (Prototyping with Attribute Grammars), a framework for building Prolog prototypes from specifications based on attribute grammars, which we have developed for supporting rapid prototyping activities in an introductory course on language processors. This framework works for general non-circular attribute grammars with arbitrary underlying context-free grammars, includes a specification language embedded in Prolog that strongly resembles the attribute grammar notations explained in the course cited, and lets students produce comprehensible prototypes from their specifications in a straightforward way.     

Towards Verification of C Programs: Axiomatic Semantics of the C-kernel Language

With the aim of the verification of programs in the C-light language [1], its kernel C-kernel is separated, and an axiomatic semantics for it is suggested. A theorem on soundness of the axiomatic semantics of C-kernel with respect to its operational semantics is proved. The C-light language is used as an input language of the program verification system, which includes a translator to C-kernel and a generator of the correctness conditions for C-kernel programs, which is based on its axiomatic semantics.     

Knowledge Acquisition and Design Using Semantics and Perception: A Case Study for Autonomous Robots

Neural Processing Letters - The pervasive use of artificial intelligence and neural networks in several different research fields has noticeably improved multiple aspects of human life. The...     

语言同现网、句法网、语义网的构建与比较

网络方法应用于语言研究是语言研究大数据时代的新趋势。语言是一个多层级的符号系统,选择哪种语言单位作为网络节点,选择哪种语言单位间的关系作为网络联结,影响到语言网络的结构和功能。该文梳理了以汉语词为单位,以同现、句法、语义关系为联结依据的几类网络构造方法,并针对同一文本构造三类网络发现: 句法网络的网络直径、平均路径长度远小于同现网络,实词在语义网络中占据中心节点位置。这提示我们网络分析方法的应用仍要以可靠的语言学理论为指导,从语言学内部出发才能更好解释各类语言网络的差异。