Telerobot-enabled HUB-CI model for collaborative lifecycle management of design and prototyping

The HUB-CI model is investigated in a telerobotic system in a client/server network to manage the lifecycle of engineering design and prototyping. The purpose of this platform is to support collaborative engineering design and proof of concept to enhance distributed team collaboration and resource utilization. The suggested platform is exemplified in two collaboration support tools and a physical prototyping platform. Structured Co-Insight Management is developed to support innovative idea exchanges and the consensus decision-making during the design process. Conflict/error detection management helps preventing conflicts and errors during the lifecycle of design and development. Physical collaboration over the network occurs when a team controls the telerobot operation during prototyping and testing in design cycles. A pilot system is implemented with a group project for the design of an electronic circuit (including both hardware and software designs). The functional assessment method is used to compare this platform to other collaborative design tools. The system presented offers unique qualitative advantages as an integrated collaboration support system.     

Improved bibliographic reference parsing based on repeated patterns

Parsing details like author names and titles out of bibliographic references of scientific publications is an important issue that has received considerable attention recently. However, most existing techniques are tailored to the highly standardized reference styles used in the last two to three decades. They do not perform well with the wide variety of reference styles used in older, historic publications. Thus, they are of limited use when creating comprehensive bibliographies covering both historic and contemporary scientific publications. This paper presents a generic approach to bibliographic reference parsing, named RefParse, which is independent of any specific reference style. Its core feature is an inference mechanism that exploits the regularities inherent in any list of references to deduce its format. In addition, our approach learns names of authors, journals, and publishers to increase the accuracy in scenarios where human users double check parsing results to increase data quality. Our evaluation shows that our approach performs comparably to existing ones with contemporary reference lists and also works well with older ones.     

Visual search tree profiling

Understanding how the search space is explored for a given constraint problem – and how it changes for different models, solvers or search strategies – is crucial for efficient solving. Yet programmers often have to rely on the crude aggregate measures of the search that are provided by solvers, or on visualisation tools that can show the search tree, but do not offer sophisticated ways to navigate and analyse it, particularly for large trees. We present an architecture for profiling a constraint programming search that is based on a lightweight instrumentation of the solver. The architecture combines a visualisation of the search tree with various tools for convenient navigation and analysis of the search. These include identifying repeated subtrees, high-level abstraction and navigation of the tree, and the comparison of two search trees. The resulting system is akin to a traditional program profiler, which helps the user to focus on the parts of the execution where an improvement to their program would have the greatest effect.     

Knowledge base support for dynamic information system management

Enterprise activities are governed by regulations and laws that are multiple, heterogeneous and not always easy to understand. The arising and/or the modification of these regulations and laws can cause a significant impact in the business context, especially in terms of enterprise information systems adaptation. Currently, there are many methodological and technological tools that facilitate the application of regulations and procedures, but they are not integrated enough to ensure a complete problem management. Therefore, they are not sufficient to support organizations and companies in the management of their business processes. In this paper we propose a methodological and technological solution, able to model, manage, execute and monitor business processes of complex domains. The system allows both the design of an information system and its prototyping as a web application, by the extension of an appropriately selected Business Process Management suite. During both the design and the usage phases of the prototyped information system, it is possible to interface with a knowledge base that contains information about regulations and aspects that characterize the enterprise (organizational chart, tasks, etc.).     

Portability of executable service-oriented processes: metrics and validation

A key promise of process languages based on open standards, such as the Web Services Business Process Execution Language, is the avoidance of vendor lock-in through the portability of processes among runtime environments. Despite the fact that today various runtimes claim to support this language, every runtime implements a different subset, thus hampering portability and locking in their users. It is our intention to improve this situation by enabling the measurement of the portability of executable service-oriented processes. This helps developers to assess their implementations and to decide if it is feasible to invest in the effort of porting a process to another runtime. In this paper, we define several software quality metrics that quantify the degree of portability of an executable, service-oriented process from different viewpoints. When integrated into a development environment, such metrics can help to improve the portability of the outcome. We validate the metrics theoretically with respect to measurement theory and construct validity using two validation frameworks. The validation is complemented with an empirical evaluation of the metrics using a large set of processes coming from several process libraries.     

A constant-force bistable mechanism for force regulation and overload protection

A novel constant-force bistable mechanism (CFBM) allowing constant contact force and overload protection is developed. When a device equipped with a CFBM is loaded by an unknown force exceeding a critical force of the CFBM, the CFBM can snap to its other stable equilibrium state to safeguard the device. The bistability of the mechanism originates from combined compression and bending of the beam structures. Finite element analyses are used to characterize the constant-force behavior and bistability of the mechanism under static loading. A design formulation is proposed to find the CFBM shape for a specified displacement range with constant output force of the mechanism. Prototypes of the CFBM are fabricated and tested. The characteristics of the CFBM predicted by theory are verified by experiments. Using the CFBM, sophisticated sensors and control system for force regulation of machining systems can be eliminated.     

Search combinators

The ability to model search in a constraint solver can be an essential asset for solving combinatorial problems. However, existing infrastructure for defining search heuristics is often inadequate. Either modeling capabilities are extremely limited or users are faced with a general-purpose programming language whose features are not tailored towards writing search heuristics. As a result, major improvements in performance may remain unexplored. This article introduces search combinators, a lightweight and solver-independent method that bridges the gap between a conceptually simple modeling language for search (high-level, functional and naturally compositional) and an efficient implementation (low-level, imperative and highly non-modular). By allowing the user to define application-tailored search strategies from a small set of primitives, search combinators effectively provide a rich domain-specific language (DSL) for modeling search to the user. Remarkably, this DSL comes at a low implementation cost to the developer of a constraint solver. The article discusses two modular implementation approaches and shows, by empirical evaluation, that search combinators can be implemented without overhead compared to a native, direct implementation in a constraint solver.     

View-based propagator derivation

When implementing a propagator for a constraint, one must decide about variants: When implementing min, should one also implement max? Should one implement linear constraints both with unit and non-unit coefficients? Constraint variants are ubiquitous: implementing them requires considerable (if not prohibitive) effort and decreases maintainability, but will deliver better performance than resorting to constraint decomposition. This paper shows how to use views to derive propagator variants, combining the efficiency of dedicated propagator implementations with the simplicity and effortlessness of decomposition. A model for views and derived propagators is introduced. Derived propagators are proved to be perfect in that they inherit essential properties such as correctness and domain and bounds consistency. Techniques for systematically deriving propagators such as transformation, generalization, specialization, and type conversion are developed. The paper introduces an implementation architecture for views that is independent of the underlying constraint programming system. A detailed evaluation of views implemented in Gecode shows that derived propagators are efficient and that views often incur no overhead. Views have proven essential for implementing Gecode, substantially reducing the amount of code that needs to be written and maintained.