Publish/subscribe communication systems where nodes subscribe to many different topics of interest are becoming increasingly more common. Designing overlay networks that connect the nodes subscribed to each distinct t...
详细信息
ISBN:
(纸本)9781424472611;9780769540597
Publish/subscribe communication systems where nodes subscribe to many different topics of interest are becoming increasingly more common. Designing overlay networks that connect the nodes subscribed to each distinct topic is hence a fundamental problem in these systems. For scalability and efficiency, it is important to keep the degree of the nodes in the publish/subscribe system low. Ideally one would like to be able not only to keep the average degree of the nodes low, but also to ensure that all nodes have equally the same degree, giving rise to the following problem: Given a collection of nodes and their topic subscriptions, connect the nodes into a graph with low average and maximum degree such that for each topic t, the graph induced by the nodes interested in t is connected. We present the first polynomial time parameterized sublinear approximation algorithm for this problem. We also propose two heuristics for constructing topic-connected networks with low average degree and constant diameter and validate our results through simulations. In fact, the results in this section are a refinement of the preliminary results by Onus and Richa in INFOCOM'09.
In service-based systems (SBS), workflows are composed of loosely coupled services. The quality of service (QoS) of composite service-based workflows needs to be considered. In doing so, various aspects of the QoS of ...
详细信息
In service-based systems (SBS), workflows are composed of loosely coupled services. The quality of service (QoS) of composite service-based workflows needs to be considered. In doing so, various aspects of the QoS of these workflows need to be assessed. In this paper, a user-centric approach is presented to assessing the confidentiality and integrity of service-based workflows, given the QoS of constituent services. Our approach incorporates the users' preferences for data sensitivity on the data processed by the workflow. It allows users to compare the amount of risk incurred by possible failure of the confidentiality or integrity functions of component services of a workflow.
The problem of determining the cutwidth of a graph is a notoriously hard problem which remains NP-complete under severe restrictions on input graphs. Until recently, non-trivial polynomial-time cutwidth algorithms wer...
详细信息
While many attacks are distributed across botnets, investigators and network operators have recently targeted malicious networks through high profile autonomous system (AS) de-peerings and network shut-downs. In this ...
详细信息
ISBN:
(纸本)9781424458387
While many attacks are distributed across botnets, investigators and network operators have recently targeted malicious networks through high profile autonomous system (AS) de-peerings and network shut-downs. In this paper, we explore whether some ASes indeed are safe havens for malicious activity. We look for ISPs and ASes that exhibit disproportionately high malicious behavior using 12 popular blacklists. We find that some ASes have over 80% of their routable IP address space blacklisted and others account for large fractions of blacklisted IPs. Overall, we conclude that examining malicious activity at the AS granularity can unearth networks with lax security or those that harbor cybercrime.
Many recommendations are proposed for accommodating multimedia content into wireless media with lower bandwidth. These formats of the content have been developed with different objectives. Now it has become really cha...
详细信息
Many recommendations are proposed for accommodating multimedia content into wireless media with lower bandwidth. These formats of the content have been developed with different objectives. Now it has become really challenging to compare all these diversified formats. In this paper, we proposed an algorithm to compare the FLV, MPEG4 and 3GP format of multimedia content using the parameters that determines their performance in wireless network. Finally, exhaustive experiments are done and the results are shown to demonstrate the merits and capabilities of the different file formats.
Users are being tracked on the Internet more than ever before as Web sites and search engines gather pieces of information sufficient to identify and study their behavior. While many existing schemes provide strong an...
详细信息
Users are being tracked on the Internet more than ever before as Web sites and search engines gather pieces of information sufficient to identify and study their behavior. While many existing schemes provide strong anonymity, they are inappropriate when high bandwidth and low latency are required. In this work, we explore an anonymity scheme for end hosts whose performance makes it possible to have it always on. The scheme leverages the natural grouping of hosts in the same subnet and the universally available broadcast primitive to provide anonymity at line speeds. Our scheme is strongly resistant against all active or passive adversaries as long as they are outside the subnet. Even within the subnet, our scheme provides reasonable resistance against adversaries, providing anonymity that is suitable for common Internet applications.
Current era of Web 2.0 is enabling new business models for using the semantic web. One such business model is leasing out computing platform of hardware and software over the internet to the tenants and is dubbed as C...
详细信息
Current era of Web 2.0 is enabling new business models for using the semantic web. One such business model is leasing out computing platform of hardware and software over the internet to the tenants and is dubbed as Cloud computing. The anticipated future trend of computing is believed to be this cloud computing as it promises a lot of benefits like no capital expenditure, speed of application deployment, shorter time to market, lower cost of operation and easier maintenance for the tenants. This paper analyses how cloud computing on the background of Web 2.0 is going to impact the software engineering process to develop quality software. As the cloud provider is an external entity or third party, how difficult will be the interaction with them? How to separate the roles of SW engineers and cloud providers? SW engineering should include framework activities to leverage all the benefits of cloud computing systematically and strategically. This paper extends the traditional agile process model named Extreme Programming (XP) and integrates interaction with the cloud provider to facilitate acceptance of cloud computing.
Cloud computing has received significant attention recently. This paper presents real-time issues related to cloud computing, such as multi-tenancy architecture, scheduling, paralleled computing and proposes a framewo...
详细信息
Cloud computing has received significant attention recently. This paper presents real-time issues related to cloud computing, such as multi-tenancy architecture, scheduling, paralleled computing and proposes a framework for real-time service-oriented cloud computing. Specially, we propose a novel real time architecture which solve the new challenges in Cloud computing.
Cloud computing often uses the multi-tenancy architecture where tenants share system software. To support dynamically increasing demands from multi-tenants, the cloud service providers have to duplicate computing reso...
详细信息
Cloud computing often uses the multi-tenancy architecture where tenants share system software. To support dynamically increasing demands from multi-tenants, the cloud service providers have to duplicate computing resources to cope with the fluctuation of requests from tenants. This is currently handled by virtualization and duplication at the application level in the existing cloud environment, such as Google App Engine. However, duplicating at the application level only may result in significant resource waste as the entire application is duplicated. This paper proposes a two-tier SaaS scaling and scheduling architecture that works at both service and application levels to save resources, and the key idea is to increase the resources to those bottleneck components only. Several duplication strategies are proposed, including lazy duplication and pro-active duplication to achieve better system performance. Additionally, a resource allocation algorithm is proposed in a clustered cloud environment. The experiment results showed that the proposed algorithms can achieve a better resource utilization rate.
Cloud computing often uses a multi-tenant architecture where tenants share application and system software. Request prioritization presents a challenge in this architecture. Tenant may have individual (local) prioriti...
详细信息
Cloud computing often uses a multi-tenant architecture where tenants share application and system software. Request prioritization presents a challenge in this architecture. Tenant may have individual (local) prioritization requirements, and these requirements can be different for different tenants. The shared application must use a global priority scheme for requests from all the tenants. This paper proposes an effective model to prioritize service requests from multiple tenants while preserving local priorities from individual tenant requests. This paper proposes the Crystalline Mapping (CM) algorithm which maps local priorities from individual tenants to global priorities. The algorithm also maximizes revenues within the local-to global priority mapping constraints. The performance of the model is evaluated by the total business value, the QoS measurement, and a fairness measure. The model has been evaluated using simulation based on real-world data, and the results are consistent with the mathematical model.
暂无评论