IT architecture meets the real (legal) world

Unfortunately for IT professionals, e-mail represents only the tip of the iceberg in how legal and regulatory duties will impact IT operations. In addition to privacy issues, regulators and other legal officials have already expressed interest in intruding into data center operations for audits of digital rights management (distribution of copyrighted materials) and taxes. They also want to determine whether e-commerce personalization engines have the impact of illegally redlining users. (Redlining is the illegal practices of a lending institution that denies loans or restricts the number of loans for certain areas of a community. There have also been redlining problems in the insurance industry.) Data centers house information, and information is of critical interest to legal and regulatory authorities. The net result is that IT architecture isn't just about technology any more. The last year's market realities made it clear that everyone must worry about the fiduciary realities of return on investment and total cost of ownership. Now that the rest of the world is catching up, IT architects need to deal with the legal realities imposed by governments and regulatory agencies. It is argued that companies that host e-mail should prepare to cooperate with law enforcement authorities and comply with search warrants or risk having their systems seized and carted away     

Logical approximation for program analysis

The abstract interpretation of programs relates the exact semantics of a programming language to a finite approximation of those semantics. In this article, we describe an approach to abstract interpretation that is based in logic and logic programming. Our approach consists of faithfully representing a transition system within logic and then manipulating this initial specification to create a logical approximation of the original specification. The objective is to derive a logical approximation that can be interpreted as a terminating forward-chaining logic program; this ensures that the approximation is finite and that, furthermore, an appropriate logic programming interpreter can implement the derived approximation. We are particularly interested in the specification of the operational semantics of programming languages in ordered logic, a technique we call substructural operational semantics (SSOS). We show that manifestly sound control flow and alias analyses can be derived as logical approximations of the substructural operational semantics of relevant languages.     

Logical Equivalence for Subtyping Object and Recursive Types

Subtyping in first order object calculi is studied with respect to the logical semantics obtained by identifying terms that satisfy the same set of predicates, as formalised through an assignment system. It is shown that equality in the full first order ς-calculus is modelled by this notion, which in turn is included in a Morris-style contextual equivalence. U. de’Liguoro’s research was partially supported by project PRIN’05 prot. 2005015785_003.     

Using Physical and Logical Constraints for Invoice Understanding

This work presents a methodology for invoice understanding. The invoices of our domain can be grouped into classes according to their logo. The understanding phase is based on two knowledge levels: a specific knowledge for each class, called a document model; and knowledge on the whole domain of interest, called a domain model. The invoices of a known class are understood by its document model, while the invoices of an unknown class are understood by using the domain model. The main contribution of this work is related to the use of the physical and logical constraints of the domain of interest for document understanding, without using an OCR system. Our approach has been tested by some experiments that are intended to identify some regions within invoices of unknown classes. In most cases, the results have shown the reliability of the approach.     

Deadlock Detection and Avoidance for Shared Logical Resources

Logical resources are defined as shared passive entities that can be concurrently accessed by multiple processes. Concurrency restrictions depend upon the mode or manner in which a process may manipulate a resource. Models incorporating these single unit resources can be used to analyze information locking for consistency and integrity purposes. Mode compatibility is defined and used to derive dead-lock detection and avoidance methods. These methods generalize well-known deadlock results for single unit resources by permitting greater concurrency while still guaranteeing data consistency. This model is applicable to the standard shared (read-only) and exclusive (read-write) access modes as well as a useful subset of those proposed in the CODASYL DBMS report.     

Logical formalisms for representing bipolar preferences

Bipolar preferences distinguish between negative preferences inducing what is acceptable by complementation and positive preferences representing what is really satisfactory. This article provides a review of the main logics for preference representation. Representing preferences in a bipolar logical way has the advantage of enabling us to reason about them, while increasing their expressive power in a cognitively meaningful way. In the article, we first focus on the possibilistic logic setting and then discuss two other logics: qualitative choice logic and penalty logic. Finally, an application of bipolar preferences querying systems is outlined. © 2008 Wiley Periodicals, Inc.     

A Deterministic Logical Semantics for Esterel

Esterel is a synchronous design language for the specification of reactive systems. There exist two main semantics for Esterel. On the one hand, the logical behavioral semantics provides a simple and compact formalization of the behavior of programs using SOS rules. But it does not ensure deterministic executions for all programs and all inputs. As non-deterministic programs have to be rejected as incorrect, this means it defines behaviors for incorrect programs, which is not convenient. On the other hand, the constructive semantics is deterministic (amongst other properties) but at the expense of a much more complex formalism. In this work, we construct and thoroughly analyze a new deterministic semantics for Esterel that retains the simplicity of the logical behavioral semantics, from which it derives. In our view, it provides a much better framework for formal reasoning about Esterel programs.     

Logical foundations for representing object-oriented systems

Abstract

Object-oriented programming languages are designed for computing or simulating the behaviour of interacting objects, but their encapsulated contexts and procedural methods are not well suited to non-procedural techniques in theorem provers, optimizers, and automated design and analysis tools. Logic is the non-procedural system par excellence, but the predicate calculus notation for logic is awkward for representing and reasoning about encapsulated contexts. Conceptual graphs are a graphic system of logic that is better suited to O-O systems. First, they explicitly represent the contexts that are ignored or obscured in predicate calculus. Second, Peirce's rules of inference for reasoning with graphs are explicitly formulated in terms of contexts and the conditions for importing and exporting information from contexts. This article describes the context mechanisms of conceptual graphs, the rules of inference for reasoning with the graphs, and their use as a design language for object-oriented systems.     

Logical Semantics for the Rewriting Calculus

The Rewriting Calculus has been proposed as a language for defining term rewriting strategies. Rules are explicitly represented as terms, and are applied explicitly to other terms to transform them. Sets of rules may be applied to (sets of) terms non-deterministically to obtain sets of results. Strategies are implemented as rules which accept other rules as arguments and apply them in certain ways. This paper describes work in progress to strengthen the Rewriting Calculus by giving it a logical semantics. Such a semantics can provide crucial guidance for studying the language and increasing its expressive power. The latter is demonstrated by adding support to the Rewriting Calculus for what we call higher-form rewriting, where rules rewrite other rules. The logical semantics used is based on ordered linear logic. The paper develops the ideas through several examples.     

面向对象XML数据库的逻辑基础

XML正在成为Internet上数据描述和交换的标准.面向对象的方法具有很强的建模能力,例如继承、非单调继承、多态性、复杂数据结构等.将面向对象的特征引入到XML中,可以提高XML语言的建模能力.用继承扩展XML的模式语言DTD支持元素继承、非单调多重继承、重载、阻断、多态和冲突处理机制. XML-RL是基于高级数据模型的以规则为基础的XML查询语言,用面向对象的特征扩展XML-RL支持多态元素、包含元素.系统地给出面向对象的XML数据库的基于逻辑的语法和语义.     

评价目标前提的逻辑框架

多前提决策问题是决策领域中重要的研究内容,其决策质量可反映决策理论研究的成果。在多前提决策中,目标会有多种实现方式,每种实现方式都有相应的实现难度。在多前提决策研究中,定义了目标的条件集,提出了将条件集分解到最简单形式的算法,并证明了算法的输出为目标的极小最简不完备条件集。然后,提出了条件集可信度的概念及其计算方式,利用可信度评估目标的所有极小最简不完备条件集的实现难度,并以此确定实现该目标的最优条件集。最后,给出了评价目标前提的逻辑框架O的形式定义,证明了框架O的可计算性和推理能力,并用逻辑程序Prolog实现了框架O的原型,通过对框架O的原理性实验和具体的工程应用验证了框架O的有效性。     

Logical sentences and searches

Abstract  A study of 13–14 year-old students' performance on two parallel logical reasoning tasks related to database searches is reported. In one task, given a logical sentence defining a search, students had to construct the equivalent data structure. In the other, given a data structure, they had to construct the equivalent logical sentence. Binary logical sentences including AND, OR and NOT were investigated, including tautology and contradiction. Students were more successful with sentences using AND than with sentences using OR. Negation generally produced difficulties, and essentially none could manage tautology and contradiction. Sentences using OR were more difficult, especially when they involved NOT. A common pattern was to treat OR as if it were AND. The two tasks, though formally parallel, were very different in difficulty, with the construction of sentences from a data structure being the more difficult. Both tasks were administered before and after training in the use of a database. A negligible difference in performance was seen.     

Model for knowledge and legal expert systems

This paper presents a four layer model for working with legal knowledge in expert systems. It distinguishes five sources of knowledge. Four contain basic legal knowledge found in published and unpublished sources. The fifth consists of legal metaknowledge. In the model the four basic legal knowledge sources are placed at the lowest level. The metaknowledge is placed at levels above the other four knowledge sources. The assumption is that the knowledge is represented only once. The use of metaknowledge at various levels should make it possible to use the appropriate knowledge for the problem presented to the system. The knowledge has to be represented as closely to the original format as possible for this purpose. Suitable representation formalisms for the various types of knowledge in the five knowledge sources are discussed. It is not possible to indicate a best representation formalism for each knowledge source.     

绿色评价模型的互模拟等价及逻辑保持

绿色计算中,复杂系统的绿色评价是一个重要的研究课题,其核心任务是判断运行时时间、空间资源消耗是否满足环境约束或限定.设计时,采用模型检测技术,自动、完备、高效地进行绿色评价,是一种新颖且有效的解决方案,但可能出现的状态爆炸问题将影响评价成败或效率.引入随机决策过程作为绿色评价模型;用时态逻辑刻画包含行为正确性及时间、空间资源约束的绿色评价指标;定义不确定语义理解下评价模型状态的互模拟等价规则,给出互模拟商的构造方法以及商模型调度,并比较等价语义下的行为机理;运用结构化归纳法证明互模拟等价保持评价结论.分析表明,互模拟等价可用作状态约简手段,为基于模型的绿色评价提供理论支撑和技术手段.     

Acceptable legal standards for software

The author discusses the legal issues that are involved in software protection. She discusses legal actions open to users who get a system that does not perform as expected and have exhausted all remedies that do not involve litigation. She examines how the law treats software, covering liability limitations and court actions regarding fraud or misrepresentation as well as injury and damage caused by software. The author discusses the inadequacy of current laws and offers recommendations for remedying the situation     

A Logical Model for Agent Communication Languages

The current ACL proposals show some shortcomings with respect to the definition of their semantics. Our paper aims at tackling those issues by defining an ACL semantics as a specification of the analytical effects of agent communicative acts. We analyze agent communication in terms of concepts taken from Speech Act Theory, as several researchers have already done, but move away from the mainstream view of artificial agent research, as we define communicative acts in terms of changes at the level of social relationship between agents. We take commitment to be a primitive concept underlying the social dimension of multiagent systems, and define a basic artificial institution whose aim is to provide agents with the means to affect the commitment network that binds them to each other.     

Logical programming for the telegram analysis problem

The telegram analysis problem posed by Henderson and Snowdon has been repeatedly taken into account. This paper adds yet another contribution to the literature on this problem. We propose rigorous specification methods, and describe how programs can be derived from BNF to Definite Clause Grammar in Prolog by two different methods. One method is especially useful for large scale problems and has been applied to file manipulation, and the other is applicable to simple problems.