Functionality makes APIs unique and therefore helps humans and machines decide what service they need. However, if two APIs offer similar functionality, quality attributes such as performance and ease-of-use might become a decisive factor. Several of these quality attributes are inherently subjective, and hence exist within a social context. These social parameters should be taken into account when creating personalized mashups and service compositions. The Web API description format RESTdesc already captures functionality in an elegant way, so in this paper we will demonstrate how it can be extended to include social parameters. We indicate the role these parameters can play in generating functional compositions that fulfill specified quality attributes. Finally, we show how descriptions can be personalized by exploring a user’s social graph. This ultimately leads to a more focused, on-demand use of Web APIs, driven by functionality and social parameters.

The Web is a giant repository of resources (Service and content), where Discovery and Recommendation systems are used to deliver the best ranked list of relevant web resources that meet user requirements. Nowadays, these systems are based on the simulation and automation of the user search criteria, considering the relation between consumption trends and the different kinds of users’ relationships with their virtual and physical environment, based on the information from the Social Web and mobile device sensors among others. These systems are executed once an explicit query of the user has been received; however, there are resources that are useful in specific situations, where these resources have high probability to be consumed, but, due to absence of a query they are not recommended to the users. In this regard, the question is: how to make a successful Web Resource Recommendation without the user query? In order to answer the question, this research proposal presents a novel approach to Recommend Web Resources based on Dynamic Prediction of User Consumption on the Social Web, which emulates the user behavior, the resource dynamism and the context opportunities, in real time, catching the best situations to make an asynchronous (unexpected by the user) recommendation of a useful Resources; and boost Web Resources consumption.

In this paper we present an architecture for provenance policies which can be used to describe and enact behavioural constraints in a system in order to ensure compliance with user and organisational policies. We discuss how this architecture has been used in order to manage the behaviour of the services powering an existing virtual research environment while reasoning about the relationships between users, their social network, their roles in a project, their groups and the provenance of research data.

Existing personalisation approaches, such as collaborative filtering or content based recommendations, are highly dependent on the domain and/or the source of the data. Therefore, there is a need for more accurate means to capture and model the interests of the user across domains, and to interlink them in a semantically-enhanced interest graph. We propose a new approach for multi-source, cross-genre recommendations that can exploit the heterogeneous nature of user profile data, which has been aggregated from multiple personalised web services, such as blogs, wikis and microblogs. Our approach is based on the Spreading Activation model that exploits intrinsic links between entities across a number of data sources. The proposed method is highly customizable and applicable both to generic and specific recommendation scenarios and use cases. With the growing number of Social Web applications in the enterprise (blogs, wikis, micro blogging, etc.), it becomes difficult for knowledge workers to avoid content overload and to quickly identify relevant people, communities and information. We demonstrate the application of our approach in an industrial use case that involves recommendation of social semantic data across multiple services in a distributed collaborative environment.

Service composition, which achieves the goal of value-added services, has been considered as the core technique of Service-oriented Computing (SOC). To cope with the challenge of ever-increasing number of web services, graph-based web service network has emerged as a potential solution to the state of art SOC. In such a way, composite services are constructed by applying searching algorithms to the built graph, and proved to achieve outstanding performance in complexity. However, web service network suffers two crucial disadvantages: poor connectivity and negative links, and both of them have crucial negative impact on service composition. To cope with the problems, we propose two methods in this paper. Firstly, leveraging social network analysis, we focus on enriching web service network by adding valuable services, which will play positive roles in solving poor connective problem. Secondly, we show a serious status that numerous negative links contained in the underlying networks, and then we propose to identify and remove the negative links based on users’ historical composite services.

Recently, online vendors and providers manage review systems as a mechanism to advertise their services and goods over the Web. In making their choice, clients can rely on feedback expressing the degree of satisfaction of past users with respect to such services and goods. This set of feedback, or reviews, may be filtered by categories of users, they may be affected by multiple factors, and they are elaborated in order to obtain an overall score, representing a global indicator aimed at summarising the level of quality of that service. In this paper, we concentrate on multi-factor review,~\ie a review whose value is computed assembling the scores given to a set of parameters that may affect the quality level of a service. Our interest is evaluating the relevance, or dominance, of some parameter with respect to the others. We advocate the use of the Analytic Hierarchy Process, a well-known technique born in the area of multi-criteria decision making, to derive the priorities to assign to the scores of the single parameters. We illustrate the proposal on the example of hotel reviews.

Defender-Attacker Stackelberg games are the foundations of toolsdeployed for computing optimal patrolling strategies in adversarialdomains such as the United states Federal Air Marshals Service and the UnitedStates Coast Guard, among others.In Stackelberg game models of these systems the attacker knows only theprobability that each target is covered by the defender, but isoblivious to the detailed timing of the coverage schedule.In many real-world situations, however, the attacker can observe thecurrent location of the defender and can exploit this knowledge toreason about the defender's future moves.We study Stackelberg security games in which the defender sequentiallymoves between targets, with moves constrained by an exogenouslyspecified graph, while the attacker can observe the defender's currentlocation and his (stochastic) policy concerning future moves. We offerfive contributions: (1) We model this adversarial patrolling game (APG) as a stochastic game with special structure and presentseveral alternative formulations that leverage the general non-linearprogramming (NLP) approach for computing equilibria in zero-sumstochastic games. We show that our formulations yield significantlybetter solutions than previous approaches. (2) We extend theNLP formulation for APG allow for attacks that may take multiple timesteps to unfold.(3) We provide anapproximate MILP formulation that uses discrete defender moveprobabilities. (4) We experimentally demonstrate the efficacy of anNLP-based approach, and systematically study the impact of networktopology on the results.(5) We extend our model to allow the defender to construct the graph constraining his moves, at some cost, and offer novel algorithms for this setting, finding that a MILP approximation is much more effective than the exact NLP in this setting.

A number of real-world security scenarios can be cast as a problem of transiting an area guarded by a mobile patroller, where the transiting agent aims to choose its route so as to minimize the probability of encountering the patrolling agent, and vice versa. We model this problem as a two-player zero-sum game on a graph, termed the transit game. In contrast to the existing models of area transit, where one of the players is stationary, we assume both players are mobile. We also explicitly model the limited endurance of the patroller and the notion of a base to which the patroller has to repeatedly return. Noting the prohibitive size of the strategy spaces of both players, we develop single- and double-oracle based algorithms including a novel acceleration scheme, to obtain optimum route selection strategies for both players. We evaluate the developed approach on a range of transit game instances inspired by real-world security problems in the urban and naval security domains.

In all of these problems, we have limited with researchers in other disciplines, be "on the ground" security resources which prevent full security coverage with domain experts, and examine real-world constraints at all times; instead, limited security resources must be deployed and challenges that cannot be abstracted away. Together as intelligently taking into account differences in priorities an international community of multiagent researchers, we of targets requiring security coverage, the responses of can accomplish more! the adversaries to the security posture and potential uncertainty over the types, capabilities, knowledge and priorities

Market or auction based algorithms offer effective methods for de-centralized task assignment in multi-agent teams. Typically there is an implicit assumption that agents are willing to cooperate and can be trusted to perform assigned tasks. Reciprocal collaboration may not always be a valid assumption. In cases where auctions are used for task allocation, without explicit revenue exchange, incentives are needed to enforce cooperation. An approach to incentive based trust is presented, which enables detection of team members that are not contributing and for dynamic formation of teams.