Conformance checking of service behavior

A service-oriented system is composed of independent software units, namely services, that interact with one another exclusively through message exchanges. The proper functioning of such system depends on whether or not each individual service behaves as the other services expect it to behave. Since services may be developed and operated independently, it is unrealistic to assume that this is always the case. This article addresses the problem of checking and quantifying how much the actual behavior of a service, as recorded in message logs, conforms to the expected behavior as specified in a process model.We consider the case where the expected behavior is defined using the BPEL industry standard (Business Process Execution Language for Web Services). BPEL process definitions are translated into Petri nets and Petri net-based conformance checking techniques are applied to derive two complementary indicators of conformance: fitness and appropriateness. The approach has been implemented in a toolset for business process analysis and mining, namely ProM, and has been tested in an environment comprising multiple Oracle BPEL servers.

Realising dead path elimination in BPMN

The Web Service Business Process Execution Language (BPEL) lacks any standard graphical notation. Various efforts have been undertaken to visualize BPEL using the Business Process Modelling Notation (BPMN). Although this is straightforward for the majority of concepts, it is tricky for the full BPEL standard, partly due to the insufficiently specified BPMN execution semantics. The upcoming BPMN 2.0 revision will provide this clear semantics. In this paper, we show how the dead path elimination (DPE) capabilities of BPEL can be expressed with this new semantics and discuss the limitations. We provide a generic formal definition of DPE and discuss resulting control flow requirements independent of specific process description languages.

Flexible service systems

Service science combines scientific, management, and engineering disciplines to improve the understanding of how service systems cooperate to create business value. Service systems are complex configurations of people, technologies, and resources that coexist in a common environment of service provisioning. While the general concepts of service science are understood and agreed upon, the representation of service systems using models is still in its infancy. In this chapter, we look at business processes and their role in properly representing service systems. We propose flexible process graphs, a high-level process modeling language, and extend it in order to specify service systems and their compositions within shared environments in a flexible way. The discussion in this chapter is the first step towards a formal description of service science environment, including service systems, networks, and whole ecology.

Explanation of relevance judgement discrepancy with quantum interference

A key concept in many Information Retrieval (IR) tasks, e.g. document indexing, query language modelling, aspect and diversity retrieval, is the relevance measurement of topics, i.e. to what extent an information object (e.g. a document or a query) is about the topics. This paper investigates the interference of relevance measurement of a topic caused by another topic. For example, consider that two user groups are required to judge whether a topic q is relevant to a document d, and q is presented together with another topic (referred to as a companion topic). If different companion topics are used for different groups, interestingly different relevance probabilities of q given d can be reached. In this paper, we present empirical results showing that the relevance of a topic to a document is greatly affected by the companion topic’s relevance to the same document, and the extent of the impact differs with respect to different companion topics. We further analyse the phenomenon from classical and quantum-like interference perspectives, and connect the phenomenon to nonreality and contextuality in quantum mechanics. We demonstrate that quantum like model fits in the empirical data, could be potentially used for predicting the relevance when interference exists.

ADAMIS: a database for medical information systems

This paper describes the design and implementation of ADAMIS (‘A database for medical information systems’). ADAMIS is a relational database management system for a general hospital environment. Apart from the usual database (DB) facilities of data definition and data manipulation, ADAMIS supports a query language called the ‘simplified medical query language’ (SMQL) which is completely end-user oriented and highly non-procedural. Other features of ADAMIS include provision of facilities for statistics collection and report generation. ADAMIS also provides adequate security and integrity features and has been designed mainly for use on interactive terminals.

GRDB: A general purpose relational database system

This article discusses the design and development of GRDB (General Purpose Relational Data Base System) which has been implemented on a DEC-1090 system in Pascal. GRDB is a general purpose database system designed to be completely independent of the nature of data to be handled, since it is not tailored to the specific requirements of any particular enterprise. It can handle different types of data such as variable length records and textual data. Apart from the usual database facilities such as data definition and data manipulation, GRDB supports User Definition Language (UDL) and Security definition language. These facilities are provided through a SEQUEL-like General Purpose Query Language (GQL). GRDB provides adequate protection facilities up to the relation level. The concept of “security matrix” has been made use of to provide database protection. The concept of Unique IDentification number (UID) and Password is made use of to ensure user identification and authentication. The concept of static integrity constraints has been used to ensure data integrity. Considerable efforts have been made to improve the response time through indexing on the data files and query optimisation. GRDB is designed for an interactive use but alternate provision has been made for its use through batch mode also. A typical Air Force application (consisting of data about personnel, inventory control, and maintenance planning) has been used to test GRDB and it has been found to perform satisfactorily.

"Mut ei tää oo hei midsommarista!" - ruotsin kielen viestinnällinen suullinen harjoittelu yhteistoiminnallisten skeema- ja elaborointitehtävien avulla

Communicative oral practice in Swedish through collaborative schema-based and elaboration tasks The general aim of this study was to learn how to better understand foreign language communicative oral practice and to develop it as part of communicative language teaching. The language-specific aim was to study how Swedish was being practised communicatively and orally in a classroom context as part of the didactic teaching-studying-learning process, and how the students' communicative oral practice in Swedish was carried out through collaborative schema-based and elaboration tasks. The scientific problem of this study focused on the essence of foreign language communicative oral proficiency. The research questions were concerned with 1) the students' involvement in carrying out the given oral tasks; 2) the features of communication and interaction strategies; 3) thematic vocabulary, and 4) the students' experiences and conceptions of the communicative oral tasks used. The study consisted of two groups of students from a Helsinki-area school (a group of upper secondary school students, Swedish Level A, Courses 2 and 3, n=9; and a group of basic education students, Swedish Level B, Course 2, n=13). The study was carried out as a pedagogically oriented case study which included certain features of ethnographic research and where the students' teacher acted as a researcher of her own work. The communicative oral practice contained five different tasks. The research data were gathered through systematic observation, audio recordings and by a questionnaire. The data were analysed through ethnographic content analysis methods. The main research finding was that a good deal of social interaction, collaboration and communication took place between the students when involved in communicative oral practice in Swedish. The students took almost optimal advantage of the allocated training time. They mostly used Swedish when participating in interactional communication. Finnish was mostly used by the students when they were deciding how to carry out a given task, aiming at intersubjectivity or negotiating meaning. The students were relaxed when practising Swedish. They also asked for and gave linguistic help in the spirit of collaborative learning principles. This resulted in interaction between students that highlighted certain features of negotiation of meaning, scaffolding and collaborative dialogue. Asking for and giving help in language issues concentrated mainly on vocabulary, and only in a few cases on grammar or pronunciation. The students also needed the teacher as a mentor. As well, the students had an enjoyable time when practising, which was most often related to carrying out the oral tasks. The thematic vocabulary used by the students corresponded well to the thematic lexis that served as a basis for the practice. At its most efficient, this lexis was most evident when the basic education students were carrying out schema-based tasks. The students' questionnaire answers agreed with the research findings gained through systematic observation and the analysis of audio recordings. The communicative tasks planned by the teacher and implemented by the students were very much in line. The language-didactic theory as presented in this study and the research findings can be widely utilised in pre-service and in-service teacher education, as well as, more generally, when developing communicative language teaching. Key words: communicative oral practice; the Swedish language; foreign language; didactic teaching-studying-learning process; communicative language teaching; collaborative task; schema-based task; elaboration task.

Fast in-memory XPath search using compressed indexes

A large fraction of an XML document typically consists of text data. The XPath query language allows text search via the equal, contains, and starts-with predicates. Such predicates can be efficiently implemented using a compressed self-index of the document's text nodes. Most queries, however, contain some parts querying the text of the document, plus some parts querying the tree structure. It is therefore a challenge to choose an appropriate evaluation order for a given query, which optimally leverages the execution speeds of the text and tree indexes. Here the SXSI system is introduced. It stores the tree structure of an XML document using a bit array of opening and closing brackets plus a sequence of labels, and stores the text nodes of the document using a global compressed self-index. On top of these indexes sits an XPath query engine that is based on tree automata. The engine uses fast counting queries of the text index in order to dynamically determine whether to evaluate top-down or bottom-up with respect to the tree structure. The resulting system has several advantages over existing systems: (1) on pure tree queries (without text search) such as the XPathMark queries, the SXSI system performs on par or better than the fastest known systems MonetDB and Qizx, (2) on queries that use text search, SXSI outperforms the existing systems by 1-3 orders of magnitude (depending on the size of the result set), and (3) with respect to memory consumption, SXSI outperforms all other systems for counting-only queries.

A Flat Concurrent Prolog compiler for PARAM

We describe a compiler for the Flat Concurrent Prolog language on a message passing multiprocessor architecture. This compiler permits symbolic and declarative programming in the syntax of Guarded Horn Rules, The implementation has been verified and tested on the 64-node PARAM parallel computer developed by C-DAC (Centre for the Development of Advanced Computing, India), Flat Concurrent Prolog (FCP) is a logic programming language designed for concurrent programming and parallel execution, It is a process oriented language, which embodies dataflow synchronization and guarded-command as its basic control mechanisms. An identical algorithm is executed on every processor in the network, We assume regular network topologies like mesh, ring, etc, Each node has a local memory, The algorithm comprises of two important parts: reduction and communication, The most difficult task is to integrate the solutions of problems that arise in the implementation in a coherent and efficient manner. We have tested the efficacy of the compiler on various benchmark problems of the ICOT project that have been reported in the recent book by Evan Tick, These problems include Quicksort, 8-queens, and Prime Number Generation, The results of the preliminary tests are favourable, We are currently examining issues like indexing and load balancing to further optimize our compiler.

Web Services Workflows—Composition, Co-Ordination, and Transactions in Service-Oriented Computing

Web services can be seen as a newly emerging research area for Service-oriented Computing and their implementation in Service-oriented Architectures. Web services are self-contained, self-describing modular applications or components providing services. Web services may be dynamically aggregated, composed, and enacted as Web services Workflows. This requires frameworks and interaction protocols for their co-ordination and transaction support. In a Service-oriented Computing setting, transactions are more complex, involve multiple parties (roles), span many organizations, and may be long-running, consisting of a highly decentralized service partner and performed by autonomous entities. A Service-oriented Transaction Model has to provide comprehensive support for long-running propositions including negotiations, conversations, commitments, contracts, tracking, payments, and exception handling. Current transaction models and mechanisms including their protocols and primitives do not sufficiently cater for quality-aware and long running transactions comprising loosely-coupled (federated) service partners and resources. Web services transactions require co-ordination behavior provided by a traditional transaction mechanism to control the operations and outcome of an application. Furthermore, Web services transactions require the capability to handle the co-ordination of processing outcomes or results from multiple services in a more flexible manner. This requires more relaxed forms of transactions—those that do not strictly have to abide by the ACID properties—such as loosely-coupled collaboration and workflows. Furthermore, there is a need to group Web services into applications that require some form of correlation, but do not necessarily require transactional behavior. The purpose of this paper is to provide a state-of-the-art review and overview of some proposed standards surrounding Web services composition, co-ordination, and transaction. In particular the Business Process Execution Language for Web services (BPEL4WS), its co-ordination, and transaction frameworks (WS-Co-ordination and WS-Transaction) are discussed.

基于SPEM2XPDL模型转换的软件过程执行

SPEM(software process engineering metamodel)是国际标准化组织制定的标准元模型,正日益成为软件过程建模领域的行业标准,但在过程执行方面,SPEM还存在不足.将软件过程看作是一种特殊的工作流,提出了一种应用工作流运行机制支持软件过程执行的方法.通过将SPEM模型转换为XPDL(XML process definition language)模型,利用XPDL引擎支持SPEM模型的执行.制定了SPEM和XPDL之间的映射规则,设计了转换算法并开发了转换引擎.该方法被应用在SoftPM项目中,成功地基于XPDL引擎Shark实现了对软件过程模型的执行支持.

移动对象数据库模型、查询语言及实时交通流分析

提出一种移动对象数据库模型——Dynamic Transportation Network Based Moving Objects Database(简称DTNMOD),并给出了DTNMOD中基于移动对象时空轨迹的网络实时动态交通流分析方法.在DTNMOD中,交通网络被表示成动态的时空网络,可以描述交通状态、拓扑结构以及交通参数随时间的变化过程;网络受限的移动对象则用网络移动点表示.DTNMOD模型包含了完整的数据类型和查询操作的定义,因此可以在任何可扩充数据库(如PostgreSQL或SECONDO)中实现,从而得到完整的数据库模型和查询语言.为了对相关模型的性能进行比较与分析,基于PostgreSQL实现了一个原型系统并进行了一系列的实验.实验结果表明,DTNMOD提供了良好的区域查询及连接查询性能.

事件驱动的BPEL引擎架构设计与实现

WS-BPEL(Web Service Business Process Execution Language，简称BPEL)是Web服务规范族中服务复合层的重要标准。BPEL支持通过对Web服务的编制(Orchestration)来构建业务流程，从而使编程人员能够集中关注业务逻辑。BPEL引擎系统是一个支持BPEL语言描述的业务流程运行的服务器中间件系统，使用BPEL引擎可以执行BPEL语言编写的业务流程。作为一个网络服务器系统，BPEL引擎将不可避免的处理大量的并发请求。如何设计实现BPEL引擎使之能高效的处理并发将是高性能BPEL引擎设计的关键问题。 并发服务器系统通常采用多线程和事件驱动两种并发模型。传统上大多数服务器软件都建立在多线程(或多进程)模型的基础上。但在高负载条件下，过多的线程和线程间的上下文切换会造成系统较大的开销，这些开销是导致系统性能下降的主要原因。事件驱动模型是一种只采用少量固定数量线程的并发模型，一般说来，它的伸缩性更好，并且有更高的处理效率。 本文对高并发服务器系统中所使用的事件驱动模型进行了分析和研究，并且结合BPEL语言规范的特点，提出了事件驱动的BPEL引擎实现技术方案。论文重点研究了BPEL事件结构和有限状态机(Finite State Machine，简称FSM)刻画BPEL流程和活动行为的原理，针对BPEL语言语法特点，构造了完整的BPEL FSM模型，包括了状态空间和基于ECA(Event-Condition-Action)模式的状态转移规则。 在基于事件驱动模型的BPEL引擎架构原理的指导下，我们设计并实现了基于事件驱动模型的OnceBPEL2.0引擎系统。并且，我们对采用多线程模型实现的OnceBPEL1.0系统和采用事件驱动模型实现的OnceBPEL2.0系统进行了性能测试和分析比较。从我们的测试数据和分析结果可以看出，采用事件驱动模型的OnceBPEL2.0系统比采用多线程模型的OnceBPEL1.0有了较大的性能提升。

Funções analíticas da linguagem Sql do Oracle.

Funções analíticas do oracle. Função RANK. Função DENSE_RANK. Função RATIO_REPORT. Funções LAG e LEAD.