A linked data compliant framework for dynamic and web-scale consumption of web services

The While Semantic Web Services (SWS) research aims at automating Web service tasks such as discovery, orchestration and execution, its take-up is very limited so far. This is due to several reasons, such as inherent complexity of existing SWS frameworks and the considerable costs involved in creating correct SWS descriptions. In addition, while semantics are in use to enable tasks such as discovery, interaction between service consumers, providers and brokering environments is still not supported by semantic message descriptions. On the other hand, the Linked Data approach has produced a set of established principles for sharing and describing data, such as RDF as representation language and the integral use of dereferencable URIs. In this paper we propose to apply those principles to expose Web services and Web APIs and introduce a framework in which service registries as well as services contribute to the automation of service discovery, and hence, workload is distributed more efficiently. This is achieved by developing a Linked Data compliant Web services framework with that communicate with semi-centralised registries but compute their suitability for a given request themselves. All communications among different framework components are using RDF-based message protocols including service input and output. This framework aims at optimizing load balance and performance by dynamically assembling services at run time in a massively distributed Web environment

Targeted Drug Delivery using Peptoid Based Nanospheres

While medicine has improved greatly in the last couple of decades, there are negative side effects that accompany many drugs. Undesirable side effects could be greatly reduced if non-systemic drug delivery systems were used because the medicine would harm diseased cells at a much higher rate than it does healthy cells. One possible non-systemic drug delivery system is peptoid nanospheres. These nanospheres will then be linked to another peptoid that is engineered to attach almost exclusively to diseased cells. This research project is focused on designing peptoids that will form nanospheres in solution. Four specific peptoids were synthesized and tested based on previous research conducted in the Servoss lab. These peptoids were synthesized then purified using high pressure liquid chromatography. After purification was complete, circular dichroism was used to determine the relative helicity of the peptoids. The peptoids were then dried on silicon chips and scanning electron microscopy was used to test for nanosphere formation. Next, dynamic light scattering (DLS) was used to determine if the peptoids formed structures in a 4 to 1 methanol and water solution. The two peptoids that DLS indicated might be forming spheres in solution were tested using transmission electron microscopy (TEM). Circular dichroism showed that all the peptoids were helicial while scanning electron microscopy showed that one of the four peptoids formed nanospheres. This indicates that helicity is not the main factor in nanospheres formation. DLS paired with TEM indicated that one of the peptoids formed nanospheres in the 500 – 600 nm size range

Design and performance of ropes for climbing and sailing

Ropes are an important part of the equipment used by climbers, mountaineers, and sailors. On first inspection, most modern polymer ropes appear similar, and it might be assumed that their designs, construction, and properties are governed by the same requirements. In reality, the properties required of climbing ropes are dominated by the requirement that they effectively absorb and dissipate the energy of the falling climber, in a manner that it does not transmit more than a critical amount of force to his body. This requirement is met by the use of ropes with relatively low longitudinal stiffness. In contrast, most sailing ropes require high stiffness values to maximize their effectiveness and enable sailors to control sails and equipment precisely. These conflicting requirements led to the use of different classes of materials and different construction methods for the two sports. This paper reviews in detail the use of ropes, the properties required, manufacturing techniques and materials utilized, and the effect of service conditions on the performance of ropes. A survey of research that has been carried out in the field reveals what progress has been made in the development of these essential components and identifies where further work may yield benefits in the future

A Literature Survey of Cooperative Caching in Content Distribution Networks

Content distribution networks (CDNs) which serve to deliver web objects (e.g., documents, applications, music and video, etc.) have seen tremendous growth since its emergence. To minimize the retrieving delay experienced by a user with a request for a web object, caching strategies are often applied - contents are replicated at edges of the network which is closer to the user such that the network distance between the user and the object is reduced. In this literature survey, evolution of caching is studied. A recent research paper [15] in the field of large-scale caching for CDN was chosen to be the anchor paper which serves as a guide to the topic. Research studies after and relevant to the anchor paper are also analyzed to better evaluate the statements and results of the anchor paper and more importantly, to obtain an unbiased view of the large scale collaborate caching systems as a whole.Comment: 5 pages, 5 figure

The Cost of contract renegotiation: evidence from the local public sector

We construct and estimate a structural principal/agent model of contract renegotiation in the French urban transport sector in a context where operators are privately informed on their innate costs (adverse selection) and can exert cost-reducing managerial effort (moral hazard). This model captures two important features of the industry. First, only two types of contracts are used in practice by local public authorities to regulate the service: cost-plus and fixedprice contracts with positive subsidies. Second, these subsidies increase over time. Such increasing subsidies are consistent with the theoretical hypothesis that principals cannot commit not to renegotiate and contracts are renegotiationproof. We compare this situation to the hypothetical case with full commitment. The distribution of innate costs of operators is shifted upwards under this hypothetical scenario. The welfare gains of commitment are significant and accrue mostly to operators. Estimates of the weights that local governments give to the operator´s profit in their objective functions and of the social value of the cost-reducing managerial effort are obtained as by-products

GSO: Designing a Well-Founded Service Ontology to Support Dynamic Service Discovery and Composition

A pragmatic and straightforward approach to semantic service discovery is to match inputs and outputs of user requests with the input and output requirements of registered service descriptions. This approach can be extended by using pre-conditions, effects and semantic annotations (meta-data) in an attempt to increase discovery accuracy. While on one hand these additions help improve discovery accuracy, on the other hand complexity is added as service users need to add more information elements to their service requests. In this paper we present an approach that aims at facilitating the representation of service requests by service users, without loss of accuracy. We introduce a Goal-Based Service Framework (GSF) that uses the concept of goal as an abstraction to represent service requests. This paper presents the core concepts and relations of the Goal-Based Service Ontology (GSO), which is a fundamental component of the GSF, and discusses how the framework supports semantic service discovery and composition. GSO provides a set of primitives and relations between goals, tasks and services. These primitives allow a user to represent its goals, and a supporting platform to discover or compose services that fulfil them

Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio