Sensitive and specific detection of E. coli using biomimetic receptors in combination with a modified heat-transfer method

We report on a novel biomimetic sensor that allows sensitive and specific detection of Escherichia colt (E. coli) bacteria in a broad concentration range from 10(2) up to 10(6) CFU/mL in both buffer fluids and relevant food samples (i.e. apple juice). The receptors are surface-imprinted polyurethane layers deposited on stainless-steel chips. Regarding the transducer principle, the sensor measures the increase in thermal resistance between the chip and the liquid due to the presence of bacteria captured on the receptor surface. The low noise level that enables the low detection limit originates from a planar meander element that serves as both a heater and a temperature sensor. Furthermore, the experiments show that the presence of bacteria in a liquid enhances the thermal conductivity of the liquid itself. Reference tests with a set of other representative species of Enterobacteriaceae, closely related to E. coli, indicate a very low cross-sensitivity with a sensor response at or below the noise level

Assessing and Improving Interoperability of Distributed Systems

Interoperabilität von verteilten Systemen ist eine Grundlage für die Entwicklung von neuen und innovativen Geschäftslösungen. Sie erlaubt es existierende Dienste, die auf verschiedenen Systemen angeboten werden, so miteinander zu verknüpfen, dass neue oder erweiterte Dienste zur Verfügung gestellt werden können. Außerdem kann durch diese Integration die Zuverlässigkeit von Diensten erhöht werden. Das Erreichen und Bewerten von Interoperabilität stellt jedoch eine finanzielle und zeitliche Herausforderung dar. Zur Sicherstellung und Bewertung von Interoperabilität werden systematische Methoden benötigt. Um systematisch Interoperabilität von Systemen erreichen und bewerten zu können, wurde im Rahmen der vorliegenden Arbeit ein Prozess zur Verbesserung und Beurteilung von Interoperabilität (IAI) entwickelt. Der IAI-Prozess beinhaltet drei Phasen und kann die Interoperabilität von verteilten, homogenen und auch heterogenen Systemen bewerten und verbessern. Die Bewertung erfolgt dabei durch Interoperabilitätstests, die manuell oder automatisiert ausgeführt werden können. Für die Automatisierung von Interoperabilitätstests wird eine neue Methodik vorgestellt, die einen Entwicklungsprozess für automatisierte Interoperabilitätstestsysteme beinhaltet. Die vorgestellte Methodik erleichtert die formale und systematische Bewertung der Interoperabilität von verteilten Systemen. Im Vergleich zur manuellen Prüfung von Interoperabilität gewährleistet die hier vorgestellte Methodik eine höhere Testabdeckung, eine konsistente Testdurchführung und wiederholbare Interoperabilitätstests. Die praktische Anwendbarkeit des IAI-Prozesses und der Methodik für automatisierte Interoperabilitätstests wird durch drei Fallstudien belegt. In der ersten Fallstudie werden Prozess und Methodik für Internet Protocol Multimedia Subsystem (IMS) Netzwerke instanziiert. Die Interoperabilität von IMS-Netzwerken wurde bisher nur manuell getestet. In der zweiten und dritten Fallstudie wird der IAI-Prozess zur Beurteilung und Verbesserung der Interoperabilität von Grid- und Cloud-Systemen angewendet. Die Bewertung und Verbesserung dieser Interoperabilität ist eine Herausforderung, da Grid- und Cloud-Systeme im Gegensatz zu IMS-Netzwerken heterogen sind. Im Rahmen der Fallstudien werden Möglichkeiten für Integrations- und Interoperabilitätslösungen von Grid- und Infrastructure as a Service (IaaS) Cloud-Systemen sowie von Grid- und Platform as a Service (PaaS) Cloud-Systemen aufgezeigt. Die vorgestellten Lösungen sind in der Literatur bisher nicht dokumentiert worden. Sie ermöglichen die komplementäre Nutzung von Grid- und Cloud-Systemen, eine vereinfachte Migration von Grid-Anwendungen in ein Cloud-System sowie eine effiziente Ressourcennutzung. Die Interoperabilitätslösungen werden mit Hilfe des IAI-Prozesses bewertet. Die Durchführung der Tests für Grid-IaaS-Cloud-Systeme erfolgte manuell. Die Interoperabilität von Grid-PaaS-Cloud-Systemen wird mit Hilfe der Methodik für automatisierte Interoperabilitätstests bewertet. Interoperabilitätstests und deren Beurteilung wurden bisher in der Grid- und Cloud-Community nicht diskutiert, obwohl sie eine Basis für die Entwicklung von standardisierten Schnittstellen zum Erreichen von Interoperabilität zwischen Grid- und Cloud-Systemen bieten.Achieving interoperability of distributed systems offers means for the development of new and innovative business solutions. Interoperability allows the combination of existing services provided on different systems, into new or extended services. Such an integration can also increase the reliability of the provided service. However, achieving and assessing interoperability is a technical challenge that requires high effort regarding time and costs. The reasons are manifold and include differing implementations of standards as well as the provision of proprietary interfaces. The implementations need to be engineered to be interoperable. Techniques that assess and improve interoperability systematically are required. For the assurance of reliable interoperation between systems, interoperability needs to be assessed and improved in a systematic manner. To this aim, we present the Interoperability Assessment and Improvement (IAI) process, which describes in three phases how interoperability of distributed homogeneous and heterogeneous systems can be improved and assessed systematically. The interoperability assessment is achieved by means of interoperability testing, which is typically performed manually. For the automation of interoperability test execution, we present a new methodology including a generic development process for a complete and automated interoperability test system. This methodology provides means for a formalized and systematic assessment of systems' interoperability in an automated manner. Compared to manual interoperability testing, the application of our methodology has the following benefits: wider test coverage, consistent test execution, and test repeatability. We evaluate the IAI process and the methodology for automated interoperability testing in three case studies. Within the first case study, we instantiate the IAI process and the methodology for Internet Protocol Multimedia Subsystem (IMS) networks, which were previously assessed for interoperability only in a manual manner. Within the second and third case study, we apply the IAI process to assess and improve the interoperability of grid and cloud computing systems. Their interoperability assessment and improvement is challenging, since cloud and grid systems are, in contrast to IMS networks, heterogeneous. We develop integration and interoperability solutions for grids and Infrastructure as a Service (IaaS) clouds as well as for grids and Platform as a Service (PaaS) clouds. These solutions are unique and foster complementary usage of grids and clouds, simplified migration of grid applications into the cloud, as well as efficient resource utilization. In addition, we assess the interoperability of the grid-cloud interoperability solutions. While the tests for grid-IaaS clouds are performed manually, we applied our methodology for automated interoperability testing for the assessment of interoperability to grid-PaaS cloud interoperability successfully. These interoperability assessments are unique in the grid-cloud community and provide a basis for the development of standardized interfaces improving the interoperability between grids and clouds

7e Nederlandse testdag, Eindhoven, 8 November 2001 : proceedings

These are the proceedings of the seventh edition of the Nederlandse Testdag (a.k.a. Dutch Testing Day), held on November 8, 2001 in Eindhoven, The Netherlands. The increase in the complexity of software and hardware systems was the predominant concern in the software design of the last decades. This increase is still going on today. and mastering this complexity is possible, only by investigating, discussing and evaluating methods and techniques for testing such systems. The Nederlandse Testdag serves as a forum in which researchers from the industry and the academia discuss and present their latest experiences and theories in the area of testing. The initiative for organising the Nederlandse Testdag is, and has always been, the result of the combined efforts of the Dutch academia and the industry. The Nederlandse Testdag is an annual event which was first held in 1995. This year's edition again consists of one invited presentation by Jens Grabowski, on ITCN-3. and six regular presentations, both from the academia and from the industry. The presentations capture a broad field of the entire testing spectrum. In the presentation by Martin Gijsen (CMG), test automation for Graphical User Interface (GUI), dedicated and embedded systems according to the TestFrame methodology is explained. Klaas Mateboer (Collis) presents the test-tool Conclusion. René de Vries (University of Twente) reports on specification testing in practice and illustrates this by means of an example. In the presentation by Loe Feijs (Eindhoven University of Technology), testing is related to game-theory. Marcel Verhoef (Chess) and Bertil Oving (NLR) present their experiences using real-time simulation, UML and VDM to obtain more reliable spacecraft avionics. Finally, Ben van Buitenen (Baan), provides an insight in service pack testing: how to efficiently test customised software components and packages. The organisation of the Nederlandse Testdag is grateful for the sponsorship it received from the Eindhoven University of Technology, the Eindhoven Embedded Systems Institute, and the financial support from Dutch Research School IPA. We are very much indebted to CMG and Telelogic's willingness to sponsor this event financially. Over the years, both companies have profiled themselves as companies investing both time and resources in advancing the current state in testing. Finally, the organisation thanks Marcella de Rooij and EIize Russell for their organisational assistance

7e Nederlandse testdag, Eindhoven, 8 November 2001 : proceedings

These are the proceedings of the seventh edition of the Nederlandse Testdag (a.k.a. Dutch Testing Day), held on November 8, 2001 in Eindhoven, The Netherlands. The increase in the complexity of software and hardware systems was the predominant concern in the software design of the last decades. This increase is still going on today. and mastering this complexity is possible, only by investigating, discussing and evaluating methods and techniques for testing such systems. The Nederlandse Testdag serves as a forum in which researchers from the industry and the academia discuss and present their latest experiences and theories in the area of testing. The initiative for organising the Nederlandse Testdag is, and has always been, the result of the combined efforts of the Dutch academia and the industry. The Nederlandse Testdag is an annual event which was first held in 1995. This year's edition again consists of one invited presentation by Jens Grabowski, on ITCN-3. and six regular presentations, both from the academia and from the industry. The presentations capture a broad field of the entire testing spectrum. In the presentation by Martin Gijsen (CMG), test automation for Graphical User Interface (GUI), dedicated and embedded systems according to the TestFrame methodology is explained. Klaas Mateboer (Collis) presents the test-tool Conclusion. René de Vries (University of Twente) reports on specification testing in practice and illustrates this by means of an example. In the presentation by Loe Feijs (Eindhoven University of Technology), testing is related to game-theory. Marcel Verhoef (Chess) and Bertil Oving (NLR) present their experiences using real-time simulation, UML and VDM to obtain more reliable spacecraft avionics. Finally, Ben van Buitenen (Baan), provides an insight in service pack testing: how to efficiently test customised software components and packages. The organisation of the Nederlandse Testdag is grateful for the sponsorship it received from the Eindhoven University of Technology, the Eindhoven Embedded Systems Institute, and the financial support from Dutch Research School IPA. We are very much indebted to CMG and Telelogic's willingness to sponsor this event financially. Over the years, both companies have profiled themselves as companies investing both time and resources in advancing the current state in testing. Finally, the organisation thanks Marcella de Rooij and EIize Russell for their organisational assistance

On Identities in Modern Networks

Communicating parties inside computer networks use different kind of identifiers. Some of these identifiers are stable, e.g., logins used to access a specific service, some are only temporary, e.g., dynamically assigned IP addresses. This paper tackles several challenges of lawful interception that emerged in modern networks. The main contribution is the graph model that links identities learnt from various sources distributed in a network. The inferred identities result into an interception of more detailed data in conformance with the issued court order. The approach deals with network address translation, short-lived identifiers and simultaneous usage of different identities. The approach was evaluated to be viable during real network testing based on various means to learn identities of users connected to a network