A database model of debugging

Debugging a program can be viewed as performing queries and updates on a database that contains program source information as well as the state of the executing program. This approach integrates the facilities of a traditional debugger into a programming environment by providing access to runtime information through normal database query operations. We are building a programming environment in which all program information is stored in a relational database system. This system will include capabilities to provide the programmer a simple yet powerful mechanism for describing debugging requests.     

Implementing ECA rules in an active database

Traditional database systems are designed to manage large volumes of data, but rule support is generally not a strong feature. On the other hand, expert systems have the deductive capability to manage rule processing. A coupling between these two systems to support advanced database applications results in what is termed an active database. An approach to implementing active database systems is to represent knowledge as Event–Condition–Action (ECA) rules. ECA rules determine when and how to react to different kinds of events. This paper focuses on the different type of events supported by an active database CLOSE. A set of primitive and composite events is presented together with examples of their application. Event detection in this system is also discussed.     

A database design for the runtime environment of a robotic workcell

Intelligent robotic workcell activities have come to require a database framework for arranging, storing and accessing information in real-time about the workcell environment in a standard way. After a brief introduction to the theory of databases (DB), we examine the general topic of robotic workcells, identify characteristics typical of robotic applications, and then present a survey of DB-related work in the robotics domain. We then construct a set of design constraints based on our analysis of robotic applications, and describe a suitable software architecture. The paper concludes with a discussion of experience gained with two generations of DB implementations.     

Graph-based rules and transactions for parallel and active database systems

Active database management systems are becoming increasingly popular because of their relevance to several advanced and complex database applications. The need for user-defined execution orders (or control structures) for rules is well recognized by researchers of active database management systems. Priority-based approaches (e.g., numeric priorities) have been used to specify a desired control structure among rules. However, due to the fact that fixed priorities are assigned to rules, independent of different contexts in which they may be triggered, the existing approaches are not able to allow rules to be executed following different control structures when they are triggered by different events. More flexible and expressive control mechanisms are often needed for rules in advanced database applications such as CAD/CAM, CASE, CIM and flexible manufacturing systems. Since rules in database environments are executed in a transaction framework, an expressive transaction model is needed to model complex control structures among rulesuniformly. In this work, we separate the event part from the condition-action parts of a rule and associate it with a rule graph which represents a set of rules (actually a set of condition-action pairs) sharing the same control structure. Different rule graphs can be defined under different event specifications thereby enabling a set of rules to follow different control structures when triggered by different events. We also use an expressive graph-based transaction model to incorporate the control structures of rule graphs uniformly in a transaction framework. The proposed rule and transaction modeling and execution techniques have been implemented and verified on a shared-nothing multiprocessor computer nCUBE2. In this paper, we also describe the client-server architecture and different parallel transaction and rule execution techniques that have been used for the implementation. Finally, we analyze the speedup and scaleup of the implemented system.     

A methodology and tool support for managing business rules in organisations

Business rules are evidently important for organisations as they describe how they are doing business. Their value has also been recognised within the information system (IS) domain, mostly because of their ability to make applications flexible and amenable to change. In this paper, we propose a methodology that helps business people and developers to keep business rules at the business level inline with the rules that are implemented at the system level. In contrast to several existing approaches that primarily focus on business rules in the scope of an application, our methodology addresses the entire IS of an organisation. The paper also describes requirements for a tool support that would be appropriate to support the methodology.     

A concurrent rule scheduling algorithm for active rules

The use of rules in a distributed environment creates new challenges for the development of active rule execution models. In particular, since a single event can trigger multiple rules that execute over distributed sources of data, it is important to make use of concurrent rule execution whenever possible. This paper presents the details of the integration rule scheduling (IRS) algorithm. Integration rules are active database rules that are used for component integration in a distributed environment. The IRS algorithm identifies rule conflicts for multiple rules triggered by the same event through static, compile-time analysis of the read and write sets of each rule. A unique aspect of the algorithm is that the conflict analysis includes the effects of nested rule execution that occurs as a result of using an execution model with an immediate coupling mode. The algorithm therefore identifies conflicts that may occur as a result of the concurrent execution of different rule triggering sequences. The rules are then formed into a priority graph before execution, defining the order in which rules triggered by the same event should be processed. Rules with the same priority can be executed concurrently. The IRS algorithm guarantees confluence in the final state of the rule execution. The IRS algorithm is applicable for rule scheduling in both distributed and centralized rule execution environments.     

The demarcation protocol: A technique for maintaining constraints in distributed database systems

Traditional protocols for distributed database management have a high message overhead; restrain or lock access to resources during protocol execution; and may become impractical for some scenarios like real-time systems and very large distributed databases. In this article, we present the demarcation protocol; it overcomes these problems by using explicit consistency constraints as the correctness criteria. The method establishes safe limits as lines drawn in the sand for updates, and makes it possible to change these limits dynamically, enforcing the constraints at all times. We show how this technique can be applied to linear arithmetic, existential, key, and approximate copy constraints.     

A comprehensive framework for modeling set-based business rules during conceptual database design

Business rules are the basis of any organization. From an information systems perspective, these business rules function as constraints on a database helping ensure that the structure and content of the real world—sometimes referred to as miniworld—is accurately incorporated into the database. It is important to elicit these rules during the analysis and design stage, since the captured rules are the basis for subsequent development of a business constraints repository. We present a taxonomy for set-based business rules, and describe an overarching framework for modeling rules that constrain the cardinality of sets. The proposed framework results in various types constraints, i.e., attribute, class, participation, projection, co-occurrence, appearance and overlapping, on a semantic model that supports abstractions like classification, generalization/specialization, aggregation and association. We formally define the syntax of our proposed framework in Backus-Naur Form and explicate the semantics using first-order logic. We describe partial ordering in the constraints and define the concept of metaconstraints, which can be used for automatic constraint consistency checking during the design stage itself. We demonstrate the practicality of our approach with a case study and show how our approach to modeling business rules seamlessly integrates into existing database design methodology. Via our proposed framework, we show how explicitly capturing data semantics will help bridge the semantic gap between the real world and its representation in an information system.     

MATLAB图形信息数据库应用程序的开发

MATLAB图形技术采用矩阵运算方法，可以方便地绘制出各种二维和三维图形，广泛用于科学研究和工程技术。利用PB8．0数据库应用系统开发工具，结合对象连接与嵌入(OLE)技术，使用MSSQL Server2000作为后台数据库管理系统，开发出了功能强大、使用方便、用户满意的应用程序，它能灵活操作和管理MATLAB图形信息，并用实例说明了PB8．0与MSSQL Server2000的连接、数据库表的建立，以及窗体控件的设计方法和数据库应用程序的设计。     

An automatic method for the dynamic construction of abstractions of states of a formal model

A method for constructing abstractions to improve the efficiency of checking formal models is described. The state equivalence relation is weakened by ignoring insignificant attribute values. Some examples of experimental results illustrate the decrease in the verification complexity from exponential to polynomial.     

CrimeSPOT: A language and runtime for developing active wireless sensor network applications

Advances in wireless sensing and actuation technology allow embedding significant amounts of application logic inside wireless sensor networks. Such active WSN applications are more autonomous, but are significantly more complex to implement. Event-based middleware lends itself to implementing these applications. It offers developers fine-grained control over how an individual node interacts with the other nodes of the network. However, this control comes at the cost of event handlers which lack composability and violate software engineering principles such as separation of concerns. In this paper, we present CrimeSPOT as a domain-specific language for programming WSN applications on top of event-driven middleware. Its node-centric features enable programming a node’s interactions through declarative rules rather than event handlers. Its network-centric features support reusing code within and among WSN applications. Unique to CrimeSPOT is its support for associating application-specific semantics with events that carry sensor readings. These preclude transposing existing approaches that address the shortcomings of event-based middleware to the domain of wireless sensor networks. We provide a comprehensive overview of the language and the implementation of its accompanying runtime. The latter comprises several extensions to the Rete forward chaining algorithm. We evaluate the expressiveness of the language and the overhead of its runtime using small, but representative active WSN applications.     

GODA: A goal-oriented requirements engineering framework for runtime dependability analysis

Context: Many modern software systems must deal with changes and uncertainty. Traditional dependability requirements engineering is not equipped for this since it assumes that the context in which a system operates be stable and deterministic, which often leads to failures and recurrent corrective maintenance. The Contextual Goal Model (CGM), a requirements model that proposes the idea of context-dependent goal fulfillment, mitigates the problem by relating alternative strategies for achieving goals to the space of context changes. Additionally, the Runtime Goal Model (RGM) adds behavioral constraints to the fulfillment of goals that may be checked against system execution traces.Objective: This paper proposes GODA (Goal-Oriented Dependability Analysis) and its supporting framework as concrete means for reasoning about the dependability requirements of systems that operate in dynamic contexts.Method: GODA blends the power of CGM, RGM and probabilistic model checking to provide a formal requirements specification and verification solution. At design time, it can help with design and implementation decisions; at runtime it helps the system self-adapt by analyzing the different alternatives and selecting the one with the highest probability for the system to be dependable. GODA is integrated into TAO4ME, a state-of-the-art tool for goal modeling and analysis.Results: GODA has been evaluated against feasibility and scalability on Mobee: a real-life software system that allows people to share live and updated information about public transportation via mobile devices, and on larger goal models. GODA can verify, at runtime, up to two thousand leaf-tasks in less than 35ms, and requires less than 240 KB of memory.Conclusion: Presented results show GODA’s design-time and runtime verification capabilities, even under limited computational resources, and the scalability of the proposed solution.     

A technique for deriving hyponymies and overlappings from database schemes

This paper tackles the problem of semi-automatically extracting hyponymy and overlapping properties between entities belonging to heterogeneous database schemes. The technique we propose consists of two phases: the first one derives basic hyponymies and overlappings starting from a specific situation; the second one receives basic properties derived from the first phase and extracts further, more general hyponymies. In addition, the paper reports some experimental results obtained by applying the technique presented here to the database schemes of Italian Central Government Offices. Finally, it shows some applications of derived hyponymies and overlappings; in particular it illustrates how they can influence scheme integration.     

Mining association rules for anomaly detection in dynamic process runtime behavior and explaining the root cause to users

Detecting anomalies in process runtime behavior is crucial: they might reflect, on the one side, security breaches and fraudulent behavior and on the other side desired deviations due to, for example, exceptional conditions. Both scenarios yield valuable insights for process analysts and owners, but happen due to different reasons and require a different treatment. Hence a distinction into malign and benign anomalies is required. Existing anomaly detection approaches typically fall short in supporting experts when in need to take this decision. An additional problem are false positives which could result in selecting incorrect countermeasures. This paper proposes a novel anomaly detection approach based on association rule mining. It fosters the explanation of anomalies and the estimation of their severity. In addition, the approach is able to deal with process change and flexible executions which potentially lead to false positives. This facilitates to take the appropriate countermeasure for a malign anomaly and to avoid the possible termination of benign process executions. The feasibility and result quality of the approach are shown by a prototypical implementation and by analyzing real life logs with injected artificial anomalies. The explanatory power of the presented approach is evaluated through a controlled experiment with users.     

Context induction: A proof principle for behavioural abstractions and algebraic implementations

An induction principle, called context induction, is presented which is appropriate for the verification of behavioural properties of abstract data types. The usefulness of the proof principle is documented by several applications: the verification of behavioural theorems over a behavioural specification, the verification of behavioural implementations and the verification of forget-restrict-identify implementations.In particular, it is shown that behavioural implementations and forget-restrict-identify implementations (under certain assumptions) can be characterised by the same condition on contexts, i.e. (under the given assumptions) both concepts are equivalent. This leads to the suggestion to use context induction as a uniform proof method for correctness proofs of algebraic implementations.     

一个有效的分布式并行挖掘关联规则算法

提出了一个基于分布式结构的快速有效的关联规则挖掘算法,它采用了分布式结构,各节点并行计算,与相关算法相比有效地减少了通信量和候选项集数目,算法可扩展性好,实现简单。     

矢量空间数据库中关联规则的挖掘算法研究

按照矢量空间数据的特点和空间数据挖掘的要求,以GIS的空间分析和空间数据处理为工具,探讨了矢量空间数据库中关联规则挖掘的数据处理方法,提出了关联规则的挖掘算法。最后,通过实例进行了验证。     

分布式数据库多层关联规则挖掘算法研究

对分布式数据库多层关联规则挖掘的理论和方法进行了研究,提出了一种基于频繁模式树FP-tree(Freguent Pattern tree)的快速挖掘算法DMAML_FPT(Distributed Mining Algorithm of Multiple Level based on FP-tree)。与类Apriori算法相比较,该算法最多只需扫描数据库三遍,不需产生和传输大量的候选项集,减少了数据通信量,从而提高了数据挖掘的效率。 实验结果表明算法DMAML_FPT是可行和有效的。