18226102
On Synchronizing with Web Service Evolution
To catch up with today's fast changing business markets, web services has never slowed down its paces for evolution. As a consequence, service consumers have to employ in-time upgrades to guarantee continuous business integrity and avoid unnecessary runtime errors in their IT systems. However, a new web service release can involve hundreds of changes, and thus it is non-trivial for the service consumer to rapidly track and adopt relevant changes. This paper proposes a framework for facilitating the service consumer to keep synchronized with the web service evolution. On the service side, a Service Invocation Monitor is installed to monitor the interaction history of the client, a Service Delta Analyzer exports the service delta into well-formatted document, and a Release Note Customizeris configured to customize the full release note produced using the monitored interaction history and exported service delta. On the client side, the Consumer Code Customizer is used by the consumer developer to highlight the code fragments to be changed and provide facilitation linkages between the code fragments and the customized release note. An example is shown to demonstrate the usefulness of our proposal.
14513982
An Online Model Checking Tool for Safety and Liveness Bugs
Modern software model checkers are usually used to find safety violations. However, checking liveness properties can offer a more natural and effective way to detect errors, particularly in complex concurrent and distributed e-business systems. Specifying global liveness properties which should always eventually be true proves to be more desirable, but it is hard for existing software model checkers to verify liveness in real codes because doing so requires finding an infinite execution. For solving such a challenge, this paper proposes an online checking tool to verify the safety and liveness properties of complex systems. We adopt the linear temporal logic to describe the semantics of the finite model checking, use binary instrumentation to obtain the distribute states and apply a checking engine to dynamically verify the finite trace linear temporal logic properties. At last, we demonstrate the method in a distributed system using distributed protocol Paxos and achieve good results by experiments.
15004157
A Semantic QoS-Aware Discovery Framework for Web Services
Augmenting web services with explicit semantics forms the foundation of Service Oriented Architectures (SOAs) automation. As more and more Semantic Web Services (SWSs) are deployed, similar SWSs could have quite different quality-of-service (QoS) levels. The QoS-aware discovery becomes an important challenge. While some efforts try to solve it via Constraint Programming (CP), they suffer from the purely syntactic matchmaking method. Furthermore, the construction of constraints and the selection of services are completely dependent on the literal translation from QoS descriptions, which increase obstacles to actually apply CP. In this paper, we propose a semantic QoS-aware framework for SWSs discovery by combining the semantic matchmaking and CP. Initially, a QoS ontology is presented to define QoS data into service descriptions. Then the ontology reasoning is adopted to change previous syntactic matchmaking into a semantic way. Through confirming the compatibility of concepts, complex QoS conditions are solved as constraints and a selection algorithm is proposed to obtain the optimal offer. Finally, the prototype implementation of our framework is discussed and a SWSs discovery case is used to illustrate the comprehensive discovery process.
5812455
Knowledge Enhanced IT Service Management
To manage the increasing complexity of IT systems and align IT services with business is the main theme of IT Service Management (ITSM). Current ITSM architecture adopts ITU as the framework to integrate silos of operational management tools and configuration information to build an end-to-end solution based on best practices. However, it lacks of a systematic means to address an important aspect of IT operation, i.e., managing the knowledge separated in various tools and experts' minds. In this paper, a novel knowledge-enhanced architecture is proposed to improve the effectiveness and efficiency of ITSM. The essential contribution of this novel architecture is to involve a Knowledge Management Database (KMDB) which provides assistance for knowledge capture, mining, storage and sharing. The paper will discuss an approach of how to construct such a KMDB with motivating scenarios and detailed description of key components. To validate the approach, a prototype system is developed and evaluated by being applied for problem analysis on a Cisco Voice over IP (VoIP) system. The experiment results show a remarkable improvement in the effectiveness and efficiency for practical IT service management operations.
12111515
Algorithm of integrating QFD and TRIZ for the innovative design process
TRIZ, the Russian acronym of the Theory of Inventive Problem Solving, is a useful tool that can solve the problem of "how to do" effectively in the innovative design process, while QFD (Quality Function Deployment) is able to settle the problem of "what to do". Although the potential of using both QFD and TRIZ in the product design process is huge, there are little tools to integrate these two methods effectively. In this research, we describe an algorithm that can integrate QFD and TRIZ effectively for the purpose of the innovative design process. The core of the algorithm is to identify the contradictions in TRIZ by defining rules based on HOQ (House of Quality) in QFD. A software tool called TRIZmatrix is developed based on this algorithm. Application of the algorithm to the case of the airbag problem is studied in detail. The software application and the case study show the advantage of this algorithm for CAI (computer aided innovation) software development.
10702245
A wireless LAN-based indoor positioning technology
Context-aware computing is an emerging computing paradigm that can provide new or improved services by exploiting user context information. In this paper, we present a wireless-local-area-network-based (WLAN-based) indoor positioning technology. The wireless device deploys a position-determination model to gather location information from collected WLAN signals. A model-based signal distribution training scheme is proposed to trade off the accuracy of signal distribution and training workload. A tracking-assistant positioning algorithm is presented to employ knowledge of the area topology to assist the procedure of position determination. We have set up a positioning system at the IBM China Research Laboratory. Our experimental results indicate an accuracy of 2 m with a 90% probability for static devices and, for moving (walking) devices, an accuracy of 5 m with a 90% probability. Moreover, the complexity of the training procedure is greatly reduced compared with other positioning algorithms.
7625765
Solving QoS-driven Web service dynamic composition as fuzzy constraint satisfaction
The creation of value-added composite web service raises an opportunity to the formation of online B2B collaborations. However, web services are usually overlapping in functionality. How to make a choice based on non-functional factors becomes a problem that needs to be solved. In this paper, it argues that the selection of component services should be considered in a global manner and the user's QoS preferences is more appropriate to be expressed in a fuzzy way. It advocates using fuzzy set to express the user's QoS preference on a specific QoS criteria and using fuzzy expression to express the user's trade-off among QoS criteria's. The service selection problem is formalized as a fuzzy constraint satisfaction problem and deep-first branch-and-bound method is chosen to search for a solution with some adjustments to web service composition. It also develops an uncritical fuzzy consistency checking algorithm as an aid to faster search. Experiments are conducted to prove the effectiveness of the approach.
11355624
Theory and Techniques for Automatic Generation of Vulnerability-Based Signatures
In this paper, we explore the problem of creating \emph{vulnerability signatures}. A vulnerability signature is based on a program vulnerability, and is not specific to any particular exploit. The advantage of vulnerability signatures is that their quality can be guaranteed. In particular, we create vulnerability signatures which are guaranteed to have zero false positives. We show how to automate signature creation for any vulnerability that can be detected by a runtime monitor. We provide a formal definition of a vulnerability signature, and investigate the computational complexity of creating and matching vulnerability signatures. We systematically explore the design space of vulnerability signatures. We also provide specific techniques for creating vulnerability signatures in a variety of language classes. In order to demonstrate our techniques, we have built a prototype system. Our experiments show that we can, using a single exploit, automatically generate a vulnerability signature as a regular expression, as a small program, or as a system of constraints. We demonstrate techniques for creating signatures of vulnerabilities which can be exploited via multiple program paths. Our results indicate that our approach is a viable option for signature generation, especially when guarantees are desired.
14929484
An Auxiliary Ground Station Based Traffic Load Balancing Scheme for LEO Satellite Systems
In the Low Earth Orbit (LEO) satellite mobile communication system, traffic load in a spot beam fluctuates dramatically with a wide dynamic range due to the non-uniform geographical distribution of the traffic sources and the periodic satellite motion. The compromise between the utilization rate of valuable satellite channels and the blocking probability of a call causes higher proportion of channel idle time and cost of per connection. A new scheme based on auxiliary ground station (AGS) is proposed to solve this problem. The AGS is set to manage short distance calls. Simulation results illustrate that the proposed scheme balances the whole traffic load in LEO, improves the utilization rate of channels, and reduces the blocking probabilities of new calls and the dropping probabilities of handover calls. The cost of per connection is reduced at the same time.
14872443
Application-aware Interface for SOAP Communication in Web Services
SOAP protocol has emerged as the Web service communication standard. Because of the relatively poor performance, many researchers focus on improving the speed of processing SOAP message. In this paper, we propose SPI, which introduces client usage pattern to the low level SOAP process infrastructure, in order to improve the performance of some kind of Web services applications with specific communication patterns. The pack interface of SPI is an approach to reduce the number of the SOAP messages to improve the latency on client side. This SOAP optimization technique packs concurrent service requests into one SOAP message on client side, and unpacks and executes them on server side. Our implementation and performance study demonstrates the usefulness and effectiveness of the technique
4594972
New Fair Payment Protocols
Fair payment protocol is designed to guarantee fairness in electronic purchasing, that is, no party can falsely deny involvement in the transaction or having sent/received the specific items/payment. In this paper we first present an efficient fair payment protocol providing invisibility of TTP, timeliness, and standard RSA signatures as the final non-repudiation evidences. Then we present a second payment protocol which is the first one to provide abuse-freeness. Our protocols can be easily integrated into the existing electronic payment systems.