A formal support to business and architectural design for service-oriented systems

Architectural Design Rewriting (ADR) is an approach for the design of software architectures developed within Sensoria by reconciling graph transformation and process calculi techniques. The key feature that makes ADR a suitable and expressive framework is the algebraic handling of structured graphs, which improves the support for specification, analysis and verification of service-oriented architectures and applications. We show how ADR is used as a formal ground for high-level modelling languages and approaches developed within Sensoria

Description of a new actinosporean type from South African freshwater

The 1st report on actinospores described these organisms as parasites related to myxosporeans. For a long time this group of parasites was believed to represent an independent taxonomic entity. Research on actinosporeans became more intensive after it was shown that they corresponded to the intraoligochaete developmental stages of fish-parasitic myxosporeans. The relevant research includes earlier surveys, as well as studies of actinospore infection of oligochaetes in natural waters and fish farms in connection with the life cycle of myxosporeans. Relatively little data areavailable on myxosporean infections of African freshwater fishes and only a single paper appeared in Africa on their actinosporean alternative stages infecting oligochaetes. In September 2003, actinospore infection of oligochaetes collected from the mud of 2 freshwater biotopes in South Africa was studied. Using the ‘cell-well plate method’, a new aurantiactinomyxon type was found in 1.1 % of the examined Branchiura sowerbyi oligochaete specimens from Rietvlei River northwards to Johannesburg, Gauteng. In 1.5 % of Branchiura sowerbyi collected in a pond (Padda Dam), near the Rand Afrikaans University, Johannesburg, the same aurantiactinomyxon type was found. Infected oligochaetes were found only after collection, no actinosporean release was recorded in Branchiura specimens kept alive for several weeks. Actinospore infection showed high intensity in oligochaetes in both positive cases. Until now, no actinosporean stages of myxosporeans have been described from South Africa. The aurantiactinospore type presented in this paper differs from the already known types described in the special literature

A survey of coccidian infection (Apicomplexa: Eimeriidaea) of freshwater fish in South Africa

Fish coccidia, especially Goussia and Eimeria spp., are common and frequent parasites of fish. The majority of the known species has been described from the Eurasian continent. Little is known, however, of the coccidian infections of South African freshwater fish. In September 2003, 77 specimens from 7 freshwater fish species were harvested at 4 sites from rivers and ponds in the Gauteng, North West and Limpopo provinces in South Africa. The fish were surveyed for coccidian infections. Two fish species were infected with apicomplexans belonging to Goussia. In banded tilapia (Tilapia sparrmanii Smith) unsporulated oocysts of Goussia vanasi Landsberg and Paperna, 1987 were found. These sporulated in tap water within 24 hours. Another species in the gut of the chubbyhead barb (Barbus anoplusWeber) harboured sporulated oocysts in the faeces and in the intestinal epithelium. The latter species has been described as Goussia anopli. This short survey suggests that more thorough studies might reveal the occurrence of further coccidian species in South African fishes

CaSPiS: A Calculus of Sessions, Pipelines and Services

Service-oriented computing is calling for novel computational models and languages with well disciplined primitives for client-server interaction, structured orchestration and unexpected events handling. We present CaSPiS, a process calculus where the conceptual abstractions of sessioning and pipelining play a central role for modelling service-oriented systems. CaSPiS sessions are two-sided, uniquely named and can be nested. CaSPiS pipelines permit orchestrating the flow of data produced by different sessions. The calculus is also equipped with operators for handling (unexpected) termination of the partner’s side of a session. Several examples are presented to provide evidence of the flexibility of the chosen set of primitives. One key contribution is a fully abstract encoding of Misra et al.’s orchestration language Orc. Another main result shows that in CaSPiS it is possible to program a “graceful termination” of nested sessions, which guarantees that no session is forced to hang forever after the loss of its partner

A Logical Verification Methodology for Service-Oriented Computing

We introduce a logical verification methodology for checking behavioural properties of service-oriented computing systems. Service properties are described by means of SocL, a branching-time temporal logic that we have specifically designed to express in an effective way distinctive aspects of services, such as, e.g., acceptance of a request, provision of a response, and correlation among service requests and responses. Our approach allows service properties to be expressed in such a way that they can be independent of service domains and specifications. We show an instantiation of our general methodology that uses the formal language COWS to conveniently specify services and the expressly developed software tool CMC to assist the user in the task of verifying SocL formulae over service specifications. We demonstrate feasibility and effectiveness of our methodology by means of the specification and the analysis of a case study in the automotive domain

Student engagement and the learning incentive program: Evidence and applications

This paper presents the Learning Incentive Program (LIP), which is an innovative teaching resource designed to enhance a range of learning-relevant outcomes through increasing student engagement while maintaining intrinsic motivation. Specifically, the LIP involves interactive weekly online formative quizzes, primarily designed to encourage engagement. As incentive for regularly engaging in course content, completion of weekly tasks allows access to course materials for that topic (e.g., lecture notes can be obtained prior to the lecture as an incentive for engaging with the LIP). The LIP is theoretically informed, and this paper presents data supporting its effectiveness. Designed to encourage regular interaction with course materials, the LIP encourages online student-driven engagement with the material, provides interactive feedback by explaining incorrect answers, and assists students to track their progress across the semester. Evidence and applications are discussed

Development of mobile agent framework in wireless sensor networks for multi-sensor collaborative processing

Recent advances in processor, memory and radio technology have enabled production of tiny, low-power, low-cost sensor nodes capable of sensing, communication and computation. Although a single node is resource constrained with limited power, limited computation and limited communication bandwidth, these nodes deployed in large number form a new type of network called the wireless sensor network (WSN). One of the challenges brought by WSNs is an efficient computing paradigm to support the distributed nature of the applications built on these networks considering the resource limitations of the sensor nodes. Collaborative processing between multiple sensor nodes is essential to generate fault-tolerant, reliable information from the densely-spatial sensing phenomenon. The typical model used in distributed computing is the client/server model. However, this computing model is not appropriate in the context of sensor networks. This thesis develops an energy-efficient, scalable and real-time computing model for collaborative processing in sensor networks called the mobile agent computing paradigm. In this paradigm, instead of each sensor node sending data or result to a central server which is typical in the client/server model, the information processing code is moved to the nodes using mobile agents. These agents carry the execution code and migrate from one node to another integrating result at each node. This thesis develops the mobile agent framework on top of an energy-efficient routing protocol called directed diffusion. The mobile agent framework described has been mapped to collaborative target classification application. This application has been tested in three field demos conducted at Twentynine palms, CA; BAE Austin, TX; and BBN Waltham, MA

Adding weight to judgments: The role of stimulus focality on weight-related embodied cognition

Research employing metaphors to explore embodied cognition has shown bidirectional relationships between cognitions and sensory-motor stimuli, such as importance and weight (e.g., “weighty tome”). This research has typically used cognition-relevant metaphor primes (e.g., weighted backpacks when making steepness judgments, weighted clipboards when judging importance of written information) but has yet to consider the role of stimuli features like focality in these findings. The current study examined wearing a heavy versus light backpack on social judgments to explore the effect of this unrelated weight prime on established weight-relevant cognitions. Participants were 40 undergraduate psychology students who wore a heavy (~5 kg) or light ( < 1 kg) backpack while making cognitive, affective, and interpersonal judgments. No significant differences were found between the judgments as a function of backpack weight. This finding suggests that non-task-relevant metaphorical primes have no observable effect on embodied cognition. This provides the first published evidence that embodied cognition is context sensitive and discriminating, that is, not every stimuli activates every related cognition

Commercially available pressure sensors for sport and health applications: A comparative review

Pressure measurement systems have numerous applications in healthcare and sport. The purpose of this review is to: (a) describe the brief history of the development of pressure sensors for clinical and sport applications, (b) discuss the design requirements for pressure measurement systems for different applications, (c) critique the suitability, reliability, and validity of commercial pressure measurement systems, and (d) suggest future directions for the development of pressure measurements systems in this area. Commercial pressure measurement systems generally use capacitive or resistive sensors, and typically capacitive sensors have been reported to be more valid and reliable than resistive sensors for prolonged use. It is important to acknowledge, however, that the selection of sensors is contingent upon the specific application requirements. Recent improvements in sensor and wireless technology and computational power have resulted in systems that have higher sensor density and sampling frequency with improved usability – thinner, lighter platforms, some of which are wireless, and reduced the obtrusiveness of in-shoe systems due to wireless data transmission and smaller data-logger and control units. Future developments of pressure sensors should focus on the design of systems that can measure or accurately predict shear stresses in conjunction with pressure, as it is thought the combination of both contributes to the development of pressure ulcers and diabetic plantar ulcers. The focus for the development of in-shoe pressure measurement systems is to minimise any potential interference to the patient or athlete, and to reduce power consumption of the wireless systems to improve the battery life, so these systems can be used to monitor daily activity. A potential solution to reduce the obtrusiveness of in-shoe systems include thin flexible pressure sensors which can be incorporated into socks. Although some experimental systems are available further work is needed to improve their validity and reliability