A proxy object is a surrogate or placeholder that controls access to another target object. Proxies can be used to support distributed programming, lazy or parallel evaluation, access control, and other simple forms of behavioral reflection. However, wrapper proxies (like futures or suspensions for yet-to-be-computed results) can require significant code changes to be used in statically-typed languages, while proxies more generally can inadvertently violate assumptions of transparency, resulting in subtle bugs. To solve these problems, we have designed and implemented a simple framework for proxy programming that employs a static analysis based on qualifier inference, but with additional novelties. Code for using wrapper proxies is automatically introduced via a classfile-to-classfile transformation, and potential violations of transparency are signaled to the programmer. We have formalized our analysis and proven it sound. Our framework has a variety of applications, including support for asynchronous method calls returning futures. Experimental results demonstrate the benefits of our framework: programmers are relieved of managing and/or checking proxy usage, analysis times are reasonably fast, overheads introduced by added dynamic checks are negligible, and performance improvements can be significant. For example, changing two lines in a simple RMI-based peer-to-peer application and then using our framework resulted in a large performance gain. 1

Comet is an object-oriented language supporting a constraintbased architecture for local search through declarative and search components.

The Context sensitive Indoor Navigation System (CoINS) implements an architecture to develop context-aware indoor user guidance services and applications. This paper presents a detailed discussion on algorithms and architectural issues in building an indoor guidance system. We first start with the World Model and required mapping to 2D for the process of path calculation and simplification. We also compare several algorithm optimizations applied in this particular context. The system provides the infrastructure to support different techniques of presenting the path and supporting user orientation to reach a certain destination in indoor premises. 1

Abstract. Over the past few years, several technological advances have been made to enable locating people in indoor settings, where way finding is something we do on a daily basis. In a similar way as it happened with GPS and today’s popular outdoor navigation systems, indoor navigation is set to become one of the first, truly ubiquitous services that will make our living and working environments intelligent. Two critical characteristics of human way finding are destination choice and path selection. This work focuses on the latter, which traditionally has been assumed to be the result of minimizing procedures such as selecting the shortest path, the quickest or the least costly path. However, this path approximations are not necessarily the most natural paths. Taking advantage of context-aware information sources, this paper presents an easy to deploy contextaware indoor navigation system, together with an efficient spatial representation, and novel approach for path adaptation to help people find their destination according to their preferences and contextual information. We tested our system in one building with several users to estimate first an assessment of preference values, and later to compare how the paths suggested by our system correspond to those people would actually follow. The positive results of this evaluation confirm the suitability of our models and algorithms. 1

Service-Orientation (SO) is a design and integration paradigm that is based on the notion of well defined, loosely coupled services. Within SO, services are viewed as computational elements that expose functionalities in a platformindependent manner and can be described, published, discovered, and consumed across language, platform, and organizational borders. SO principles emphasize composability, by which a set of services can be composed to achieve the desired functionality. Service orchestration is the dominate approach to service compositions. A key issue in implementing service orchestrations is their efficient concurrent execution. This paper focuses on the scalability challenges of simultaneously executing many long-running service orchestration instances. We present a novel approach for implementing service orchestrations called BUST (Break-Up State Transition) that significantly improves processing rate and scalability. Categories and Subject Descriptors C.2.4 [Computer-Communication Networks]: Distributed

Abstract. Scalability, reliability and adaptability are among the key requirements for the enactment of distributed workflows. In addition, system resources should be efficiently utilized. Central workflow engines and static analysis of workflow specifications are some of the important obstacles to meeting these requirements. We propose a fully decentralized approach to workflow enactment that is not subject to these obstacles. In addition, it supports automatic recovery. The approach is of continuation-passing style, where continuations, or the reminder of the executions, are passed along with asynchronous messages for workflow enactment. Two continuations are associated to an execution: a success continuation and a failure continuation. Recovery plans for workflows are automatically generated at runtime and included in failure continuations. A prototype is implemented. 1

Adaptive Object Models are a sophisticated way of building object-oriented systems that let non-programmers customize the behavior of the system and that are most useful for businesses that are rapidly changing. Although systems based on an Adaptive Object Model are often much smaller than competitors, they can be difficult to build and to learn. We believe that the problems with Adaptive Object Models are due in part to a mismatch between their design and the languages that are used to build them. This paper describes how to avoid this mismatch by using implicit and explicit metaclasses.

The rich new terrains offered by computer music invite the exploration of new techniques to compose within them. The computational nature of the medium has suggested algorithmic approaches to composition in the form of generative musical structure at the note level and above, and audio signal processing at the level of individual samples. In the region between these levels, the domain of microsound, we may wish to investigate the musical potential of sonic particles that interrelate both signal processing and generative structure. In this thesis I present a software platform (‘Vessel’) for the exploration of such potential. In particular, a solution to the efficient scheduling of interleaved sound synthesis and algorithmic control with sample accuracy is expounded. The formal foundations, design and implementation are described, the project is contrasted with existing work, and avenues for musical application and future exploration are proposed.

In 2008 the Object Management Group (OMG) released an RFI on “dynamic business activity modeling”. The need to model case management processes was the primary motivation towards this RFI. Several vendors of business process management systems (BPMS) have expressed interest in standardization of case management modeling. Cordys, a vendor of a BPMS platform, based on service oriented architecture (SOA) technology, is one of them. Cordys is increasingly focusing on and providing support for management and improvement of business operations. This year Cordys will release the next release of its business operations platform, called BOP-4. BOP-4 includes a model-driven case management solution, smoothly integrated with BPMN. Within the OMG, the Government Domain Task Force works on standardization of records management and case files. It is expected that case management standardization will be a joint effort of the Business Modeling and Integration and Government Domain task forces. It is too early to conclude whether, eventually, a new specification will be adopted, next to BPMN, or whether case management modeling capabilities will be incorporated into the next release of BPMN. In a series of two articles the discussion around “case management modeling versus BPMN ” will be taken to the broader business process management community.