Partially interpreted schemas for CSP programming

Partially interpreted program schemas are suggested as a tool for formally specifying and defining the range of applicability of patterns of communication. The body of a schema syntactically resembles a program, but contains free variables which represent uninterpreted program sections, domains, functions, or other aspects of the program. The specification of the schema includes both applicability requirements and result assertions, as well as specifications for the free variables. A schema may be instantiated to obtain a correct program for a problem statement by matching a problem's assumptions and requirements to a schema specification, and appropriately substituting entities from the problem statement for the free variables in both the specification and the body of the schema. Examples are given of the types of schemas and specifications needed for distributed computing, and of the potential variety of instantiations.     

Cognitive processes in engineering design: a longitudinal study

Abstract

In this paper we report an empirical study of the cognitive processes of semi-expert electronics engineers pursuing real-world design projects. Extensive diary and interview data were analysed so as to reveal the organization of on-going design activity and the goals that were motivating behaviour. Our analyses indicated that subjects were implementing a highly systematic design strategy which deviated only a small amount (12%) from a top-down, depth-first procedure. Some of this deviation could be accounted for by social demands impinging on the individual designer, and whilst there was also evidence of ‘opportunistic’ deviation from a structured design approach, this did not appear to be a significant feature of our subjects' behaviour. We present a model of the design process as a set of production rules which describe an abstract ‘design schema’ for electronic engineering. This design schema embodies processes which control and co-ordinate problem-understanding and problem-structuring activity as well as the essentially top-down, depth-first pursuit of design solutions. The schema also allows for flexibility in the design process, permitting subjects to cope with contingencies arising through social influences and performance breakdowns. A further aspect of the design schema is that it encapsulates a ‘satisficing’ procedure which reflects a principle that dominated our engineers' solution-search and evaluation activity—they characteristically focused exclusively on initial, satisfactory (but usually sub-optimal) solution concepts rather than comparing alternatives with the aim of optimizing choices. We conclude our discussion by recommending facilities that we feel computer-based design aids should offer users if they are to be genuinely useful adjuncts to design activity.     

Computers and Improvisation: Using the Visual Assistant for Teaching

The Visual Assistant project is concerned with designing and implementing software that meets the needs of creative practice within theatre. As its name implies, it is concerned with visualisations and it aims to be easy to learn and easy to use, enabling theatre practitioners to produce sketches of visual ideas without the need for developed technical expertise. The paper describes four workshops that have been run as part of the software development process and which have served not only to improve the software but also clarify its relationship to practice. One important discovery has been the extent to which the medium can be used for exploration and improvisation. In this mode, the process of visual 'play' may be more important than the production of specific visual designs. The software may also be used in relation to specific set design, where it enables a large number of initial ideas to be explored without great cost. It was found that students adopted a number of distinct approaches to visualisation, even with this relatively simple tool. The next phase of the project will be to ensure that the output from this preliminary sketching tool can be input into a more sophisticated theatre modelling tool.     

Translation of Z specifications to executable code: Application to the database domain

ContextIt is well-known that the use of formal methods in the software development process results in high-quality software products. Having specified the software requirements in a formal notation, the question is how they can be transformed into an implementation. There is typically a mismatch between the specification and the implementation, known as the specification-implementation gap.ObjectiveThis paper introduces a set of translation functions to fill the specification-implementation gap in the domain of database applications. We only present the formal definition, not the implementation, of the translation functions.MethodWe chose Z, SQL and Delphi languages to illustrate our methodology. Because the mathematical foundation of Z has many properties in common with SQL, the translation functions from Z to SQL are derived easily. For the translation of Z to Delphi, we extend Delphi libraries to support Z mathematical structures such as sets and tuples. Then, based on these libraries, we derive the translation functions from Z to Delphi. Therefore, we establish a formal relationship between Z specifications and Delphi/SQL code. To prove the soundness of the translation from a Z abstract schema to the Delphi/SQL code, we define a Z design-level schema. We investigate the consistency of the Z abstract schema with the Z design-level schema by using Z refinement rules. Then, by the use of the laws of Morgan refinement calculus, we prove that the Delphi/SQL code refines the Z design-level schema.ResultsThe proposed approach can be used to build the correct prototype of a database application from its specification. This prototype can be evolved, or may be used to validate the software requirements specification against user requirements.ConclusionTherefore, the work presented in this paper reduces the overall cost of the development of database applications because early validation reveals requirement errors sooner in the software development cycle.     

Evaluating animations as student aids in learning computer algorithms

We conducted two experiments designed to examine whether animations of algorithms would help students learn the algorithms more effectively. Across the two studies we used two different algorithms — depth-first search and binomial heaps — and used two different subject populations — students with little or no computer science background and students who were computer science majors — and examined whether animations helped students acquire procedural and conceptual knowledge about the algorithms. The results suggest that one way animations may aid learning of procedural knowledge is by encouraging learners to predict the algorithm's behavior. However, such a learning improvement was also found when learners made predictions of an algorithm's behavior from static diagrams. This suggests that prediction, rather than animation per se, may have been the key factor in aiding learning in the present studies. These initial experiments served to highlight a number of methodological issues that need to be systematically addressed in future experiments in order to fully test the relationship between animation and prediction as well as to examine other possible benefits of animations on learning.     

Copresence and Its Social-Relational Antecedents in Computer-Mediated Communication: The Case of Instant Messenger

Computer-mediated communication (CMC) technologies like instant messenger have been increasingly used as a tool for interpersonal relationship development and maintenance. To better understand such use of CMC, we investigate copresence—defined as a communicator's perception of being with other communication partners through CMC—and its role in affecting the intention to continue using the medium. We explore three social-relational antecedents of copresence: prior use of the medium, perceived critical mass, and user commitment to maintain the relationship with others. Hypotheses are tested with survey data on the use of instant messenger. In general, the results support the research hypotheses. We suggest that the concept of copresence can be a novel and helpful theoretical perspective for understanding the use of CMC for social-relational purposes.     

A new paradigm of humanoid robot motion programming based on touch interpretation

Most humanoid soccer robot teams design the basic movements of their robots, like walking and kicking, off-line and manually. Once these motions are considered satisfactory, they are stored in the robot’s memory and played according to a high level behavioral strategy. Much time is spent in the development of the movements, and despite the significant progress made in humanoid soccer robots, the interfaces employed for the development of motions are still quite primitive. In order to accelerate development, an intuitive instruction method is desired. We propose the development of robot motions through physical interaction. In this paper we propose a ”teaching by touching” approach; the human operator teaches a motion by directly touching the robot’s body parts like a dance instructor. Teaching by directly touching is intuitive for instructors. However, the robot needs to interpret the instructor’s intention since tactile communication can be ambiguous. This paper presents a method to learn the interpretation of the touch meaning and investigates, through experiments, a general (shared among different users) and intuitive touch manner.     

基于XML的信息系统集成的可视化与匹配

近年来,信息架构的匹配显示了在诸如数据库集成等领域的重大应用。针对这一具有挑战性的问题,提出一个可视化匹配的模型,并开发一个半自动的集成工具。此模型主要用于基于XML的信息系统中的数据集成。该模型把一个新颖的可视化界面和以算法为基础的推荐引擎结合在一起。经过用户的实际操作和使用,证明该模型对于基于XML的信息系统中的数据集成既简单又快速。     

FI3D: direct-touch interaction for the exploration of 3D scientific visualization spaces

We present the design and evaluation of FI3D, a direct-touch data exploration technique for 3D visualization spaces. The exploration of three-dimensional data is core to many tasks and domains involving scientific visualizations. Thus, effective data navigation techniques are essential to enable comprehension, understanding, and analysis of the information space. While evidence exists that touch can provide higher-bandwidth input, somesthetic information that is valuable when interacting with virtual worlds, and awareness when working in collaboration, scientific data exploration in 3D poses unique challenges to the development of effective data manipulations. We present a technique that provides touch interaction with 3D scientific data spaces in 7 DOF. This interaction does not require the presence of dedicated objects to constrain the mapping, a design decision important for many scientific datasets such as particle simulations in astronomy or physics. We report on an evaluation that compares the technique to conventional mouse-based interaction. Our results show that touch interaction is competitive in interaction speed for translation and integrated interaction, is easy to learn and use, and is preferred for exploration and wayfinding tasks. To further explore the applicability of our basic technique for other types of scientific visualizations we present a second case study, adjusting the interaction to the illustrative visualization of fiber tracts of the brain and the manipulation of cutting planes in this context.     

A self-adaptive multi-engine solver for quantified Boolean formulas

In this paper we study the problem of engineering a robust solver for quantified Boolean formulas (QBFs), i.e., a tool that can efficiently solve formulas across different problem domains without the need for domain-specific tuning. The paper presents two main empirical results along this line of research. Our first result is the development of a multi-engine solver, i.e., a tool that selects among its reasoning engines the one which is more likely to yield optimal results. In particular, we show that syntactic QBF features can be correlated to the performances of existing QBF engines across a variety of domains. We also show how a multi-engine solver can be obtained by carefully picking state-of-the-art QBF solvers as basic engines, and by harnessing inductive reasoning techniques to learn engine-selection policies. Our second result is the improvement of our multi-engine solver with the capability of updating the learned policies when they fail to give good predictions. In this way the solver becomes also self-adaptive, i.e., able to adjust its internal models when the usage scenario changes substantially. The rewarding results obtained in our experiments show that our solver AQME—Adaptive QBF Multi-Engine—can be more robust and efficient than state-of-the-art single-engine solvers, even when it is confronted with previously uncharted formulas and competitors.     

An approach to test-driven development of conceptual schemas

Test-Driven Development (TDD) is an extreme programming development method in which a software system is developed in short iterations. In this paper we present the Test-Driven Conceptual Modeling (TDCM) method, which is an application of TDD for conceptual modeling, and we show how to develop a conceptual schema using it. In TDCM, a system's conceptual schema is incrementally obtained by performing three kinds of tasks: (1) Write a test the system should pass; (2) Change the schema to pass the test; and (3) Refactor the schema to improve its qualities. We also describe an integration approach of TDCM into a broad set of software development methodologies, including the Unified Process development methodology, the MDD-based approaches, the storytest-driven agile methods and the goal and scenario-oriented requirements engineering methods. We deal with schemas written in UML/OCL, but the TDCM method could be adapted to the development of schemas in other languages.     

A compact planar distributed tactile display and effects of frequency on texture judgment

This paper describes the development of a planar distributed tactile display and the evaluation of the results of its effectiveness for displaying textures. The tactile display is composed of a 6 × 5 pin array actuated by 30 piezoelectric bimorphs. The distance between each pin's centers is 1.8 mm. Vertical excursion of each pin is controlled over a 0–0.7 mm range. Perceptual experiments were conducted to evaluate the performance of the system under three conditions: active touch, passive touch with vibration and passive touch without vibration. The experimental results showed that vibrational stimuli helped subjects discriminate tactile patterns. Measurements of the error rate during discrimination tasks were used to find an optimal vibration frequency for stimuli presented at a constant sensation level (32 SLdB above threshold). The experiment was repeated, this time holding the energy transferred mechanically to the fingertip tissue constant. At low frequencies, we found that the passive stimulation allowed subjects to discriminate just as well as active touch of static stimuli did. The results suggested new possibilities for displaying texture using passive touch, constant energy and spatially varied vibration frequency.     

Learning accurate and concise naïve Bayes classifiers from attribute value taxonomies and data

In many application domains, there is a need for learning algorithms that can effectively exploit attribute value taxonomies (AVT)—hierarchical groupings of attribute values—to learn compact, comprehensible and accurate classifiers from data—including data that are partially specified. This paper describes AVT-NBL, a natural generalization of the naïve Bayes learner (NBL), for learning classifiers from AVT and data. Our experimental results show that AVT-NBL is able to generate classifiers that are substantially more compact and more accurate than those produced by NBL on a broad range of data sets with different percentages of partially specified values. We also show that AVT-NBL is more efficient in its use of training data: AVT-NBL produces classifiers that outperform those produced by NBL using substantially fewer training examples.     

Tool support for the design and management of context models

A central task in the development of context-aware applications is the modeling and management of complex context information. In this paper, we present the NexusEditor, which can ease this task by providing a graphical user interface to design schemas for spatial and technical context models, interactively create queries, send them to a server and visualize the results. One main contribution is to show how schema awareness can improve such a tool: The NexusEditor dynamically parses the underlying data model and provides additional syntactic checks, semantic checks, and short-cuts based on the schema information. Furthermore, the tool helps to design new schema definitions based on the existing ones, which is crucial for an iterative and user-centric development of context-aware applications. Finally, it provides interfaces to existing information spaces and visualization tools for spatial data like GoogleEarth.     

Smart server: Concepts and applications

The Internet has become a critical tool for information and communication that has reached much of the developed world. It is comprised of numerous components, of which the World Wide Web (WWW) is the largest and fastest growing. Efficient functionality of the WWW depends on a multitude of web servers in operation throughout the world. A web server, in and of itself, is frequently inefficient. We propose several concepts—all of which involve the assimilation of computational intelligence into a web server—that will ultimately improve its performance. A web server would then become a “smart” server that will learn during its operation and subsequently adapt its components and behavior to optimize many of its functions and modes of operation. Furthermore, it will be more secure, robust, and reliable via a hierarchical security system. A smart server will ultimately be more efficient, thus providing an enhanced experience for the multitude of people making use of the WWW every day. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 1139–1154, 2007.     

A composite approach to automating direct and indirect schema mappings

Automating schema mapping is challenging. Previous approaches to automating schema mapping focus mainly on computing direct matches between two schemas. Schemas, however, rarely match directly. Thus, to complete the task of schema mapping, we must also compute indirect matches. In this paper, we present a composite approach for generating a source-to-target mapping that contains both direct and many indirect matches between a source schema and a target schema. Recognizing expected-data values associated with schema elements and applying schema-structure heuristics are the key ideas needed to compute indirect matches. Experiments we have conducted over several real-world application domains show encouraging results, yielding about 90% precision and recall measures for both direct and indirect matches.     

The Autosar XML Schema and Its Relevance for Autosar Tools

The Autosar standard represents an emerging approach to unifying virtually all aspects of the development workflow of automotive embedded software. The standard features an XML schema used as a basis for interchanging documents containing Autosar model content. Although the schema is primarily for document exchange, it could also be the basis for creating a metamodel. However, a tool metamodel should probably be designed differently.