14158906
A New Certified Email Protocol
As a continuative effort of our WICS'05 paper, a new certified Email protocol is proposed. Email is a standard communication method nowadays but certified email is poorly developed and has very limited application. A certified email protocol assures non-repudiability which means that if the email is successfully sent, the sender cannot deny s/he has actually sent the mail and the recipient cannot deny s/he has actually received it. Our protocol uses an efficient RSA-based convertible signature with non- interactive partial signature proof method and additively split signing secret key.
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.
28493483
Abuse-Free Item Exchange
Electronic exchange is widely used in e-commerce systems. This paper mainly discusses abuse-freeness in general item exchange protocol for two parties. Based on convertible signature scheme and adapted designated verifier proof, an efficient item exchange protocol is proposed to satisfy many interesting requirements including fairness, timeliness and strong abuse-freeness.
18986616
Verifying Real-Time Systems using Explicit-time Description Methods
Timed model checking has been extensively researched in recent years. Many new formalisms with time extensions and tools based on them have been presented. On the other hand, Explicit-Time Description Methods aim to verify real-time systems with general untimed model checkers. Lamport presented an explicit-time description method using a clock-ticking process (Tick) to simulate the passage of time together with a group of global variables for time requirements. This paper proposes a new explicit-time description method with no reliance on global variables. Instead, it uses rendezvous synchronization steps between the Tick process and each system process to simulate time. This new method achieves better modularity and facilitates usage of more complex timing constraints. The two explicit-time description methods are implemented in DIVINE, a well-known distributed-memory model checker. Preliminary experiment results show that our new method, with better modularity, is comparable to Lamport's method with respect to time and memory efficiency.
206892695
A new dependable exchange protocol
As electronic transaction becomes common practice in real-world business, its dependability develops into a major concern, especially in critical transactions, e.g., electronic payment and electronic contract signing. Many recent fair-exchange protocols can recover the transaction from network failures; however, few can survive local system failures. In this paper, we propose a new Dependable Exchange Protocol. With proper convertible signature scheme and message logging method, the exchange protocol provides a recovery method for network and local system failures. To the best of our knowledge, this protocol is the first fault-tolerant exchange protocol in the context of offline TTP and asynchronous channels.
15968114
An Efficient Explicit-time Description Method for Timed Model Checking
Timed modelchecking,the methodtoformallyverifyreal-timesystems, is attractingincreasingatten-tion from both the model checking community and the real-time community. Explicit-time descrip-tion methods verify real-time systems using general model constructs found in standard un-timedmodel checkers. Lamport proposed an explicit-time description method [17] using a clock-tickingprocess (Tick) to simulate the passage of time together with a group of global variables to model timerequirements. Two methods, the Sync-based Explicit-time Description Methodusing rendezvoussynchronization steps and the Semaphore-based Explicit-time Description Methodusing only oneglobal variable were proposed [27, 26]; they both achieve better modularity than Lamport’s methodin modelingthe real-time systems. In contrast to timed automatabased model checkerslike UPPAAL[7], explicit-time description methods can access and store the current time instant for future calcula-tions necessary for many real-time systems, especially those with pre-emptive scheduling. However,the Tick process in the above three methods increments the time by one unit in each tick; the statespaces therefore grow relatively fast as the time parameters increase, a problem when the system’stime period is relatively long. In this paper, we propose a more efﬁcient method which enables theTick process to leap multiple time units in one tick. Preliminary experimentalresults in a high perfor-mance computing environment show that this new method signiﬁcantly reduces the state space andimproves both the time and memory efﬁciency.
33974786
Mining a Complete Set of Both Positive and Negative Association Rules from Large Databases
Association rule mining is one of the key issues in knowledge discovery. In recent years, negative association rule mining has attracted remarkable attention. This paper presents a notion of validity for both positive and negative association rules, which is considered intuitive and necessary. Then, a mining algorithm to find all rules in light of completeness is proposed. In doing so, several pruning strategies based on the upward closure property are developed and incorporated into the algorithm so as to guarantee the computational efficiency.
6971305
Video streaming over multi-hop wireless networks
In this paper, we considered the problem of transporting layered video over erroneous multi-hop wireless networks and proposed a distributed system. Our proposed distributed scheme is comprised of distributed control (DC), distributed buffer (DB) and distributed error control schemes. The DC scheme improves the efficiency of the network bandwidth usage and reduces the end-to-end delay of the streaming application. End-to-end delay jitter can be reduced by proper use of the DB nodes' buffer. Replacing the traditional EEC and ARQ with our distributed FEC and ARQ scheme reduces the error-protection overhead and ARQ delay and improves the wireless channel throughput. A layered video module is developed in GlomoSim 2.03 for video streaming application. We simulated our distributed scheme employing the layered video module in GlomoSim 2.03. Our simulation results confirm that QoS of streaming video over erroneous multi-hop wireless network can be improved using our proposed distributed scheme.
189947
Evaluating Service Identification with Design Metrics on Business Process Decomposition
One of the key activities to construct a successful Service-Oriented Architecture (SOA) is the identification of services with the right level of abstraction. Most of existing SOA design methodologies advocate identifying services from the top-down decomposition of business processes. However, the identification quality in these methodologies heavily depends on the expertise and experience of individual designers. The ability to quantitatively evaluate service identification is absolutely needed. In this paper, we propose an approach that supports such evaluation by applying the measurement technology to the service-based business process decomposition. A model to capture related architectural elements with their relationships is presented. A set of design metrics are proposed for measuring various features of identified services in the service portfolio, including service granularity, coupling, cohesion, and business entity convergence. To apply the approach, a prototypical measurement tool for service identification is developed. An automotive work order scenario is used as an illustration example to explain our approach and demonstrate its effectiveness.
15067408
Adapting LDA Model to Discover Author-Topic Relations for Email Analysis
Analyzing the author and topic relations in email corpus is an important issue in both social network analysis and text mining. The Author-Topic model is a statistical model that identifies the author-topic relations. However, in its inference process, it ignores the information at the document level, i.e., the co-occurrence of words within documents are not taken into account in deriving topics. This may not be suitable for email analysis. We propose to adapt the Latent Dirichlet Allocation model for analyzing email corpus. This method takes into account both the author-document relations and the document-topic relations. We use the Author-Topic model as the baseline method and propose measures to compare our method against the Author-Topic model. We did empirical analysis based on experimental results on both simulated data sets and the real Enron email data set to show that our method obtains better performance than the Author-Topic model.
6690308
PEPA Analysis of MAP Effects in Hierarchical Mobile IPv6
To overcome the drawbacks of the mobile IPv6 protocol on handling local mobility management, IETF proposed the HMIPv6 protocol which introduces an intermediate mobility anchor point (MAP) to hide the movement of a mobile node within a local area. However, the MAP forms a bottleneck in the network since all the traffic destined for its served nodes has to go through it. Most research on HMIPv6 focuses on protocol optimisation, and performance analysis of HMIPv6 is usually simulation-based. In this paper, we employ a performance evaluation formalism named PEPA to investigate the performance tradeoffs of MAPs in HMIPv6. Performance measures such as response time and MAP utilisation are presented.