44761977
Executable Specification and Analysis for the Design of Concurrent Object-Oriented Systems
This paper investigates the analysis of concurrent OO designs using a formal, executable specification technique called G-Net. After presenting an overview of the G-Net technique, we show how to use the G-Net notation to specify the concurrent OO systems. A formal transformation technique, which translates a G-Net specification to a semantically equivalent PrT-net, is presented. The resultant PrT-net can then be formally analyzed. The practical significance of this approach in fault-tolerant systems and distributed multimedia systems design is discussed.
24822225
Achieving a Better Middleware Design through Formal Modeling and Analysis
9746543
Design an Interoperable Mobile Agent System Based on Predicate Transition Net Models
Mobile agents provide an effective and flexible style to develop advanced distributed systems. In order to promote interoperability and ensure the quality of mobile agent systems, it is necessary to formalize software architecture of mobile agent systems. In this paper, we not only define the software architecture of interoperable mobile agent systems using predicate transition nets, but also analyze the interoperability between agents. In addition, a formal model-driven design method to develop mobile agent systems is described with examples. Our method naturally integrates formal methods and practical approaches in the agent system design phase. The method can be used to develop other complex software systems as well.
10829689
A Framework for the Modeling and Prototyping of Distributed Information Systems
The major issues in designing Distributed Information Systems (DIS) include localization of control and data, inherent concurrency, intensive interactions among computation agents, history sensitivity, dynamic configuration and continuous system change and evolution. We propose a framework, called the G-Net model, for the specification, modeling and prototyping of DIS. The G-Net model not only provides a flexible notation to represent the executable specification of DIS through G-Net instantiation, but also offers a novel style of decentralized concurrent computation, allowing flexible inter-agent communication and interaction. A prototype of the G-Net framework has been implemented on workstations connected by a local network.
13531819
A visual approach to XML document design and transformation
This paper presents a visual approach to the representation and validation of multimedia document structures specified in XML and transformation of one structure to another. The underlying theory of our approach is a context-sensitive graph grammar formalism. The paper demonstrates the conciseness and expressiveness of the graph grammar formalism. An example XML structure is provided and its graph grammar representation, validation and transformation to a multimedia representation are presented.
2725088
Architecture-driven modeling of real-time concurrent systems with applications in FMS
Abstract Petri nets have become increasingly popular for flexible manufacturing systems (FMS) modeling and control because they accurately capture the concurrent, non-deterministic and time-dependent properties of the systems. While offering many advantages, conventional Petri net models suffer from some serious problems that limit their usability as design models for complex FMS. Central to these problems is the lack of an engineering support for incremental design, refinement, and analysis of large-scale systems. In this paper, we present an architecture-driven approach for the modeling and design of FMS that effectively addresses the problems while leveraging the strengths of Petri nets. The approach has two major aspects: The first is a Net-based and Object-based Architectural Model (NOAM) that introduces a well-founded architectural framework into the Petri nets notation and lays a foundation to support formal design. The second is a modeling method based on NOAM that uses architecture decomposition and refinement as the basis to reduce design complexity, to provide smooth transition from informal to formal design, and to support incremental refinement and analysis. A case study using NOAM for FMS modeling is provided to show the applicability of our approach.
1196454
Resolving the Simultaneous Resettability Conjecture and a New Non-Black-Box Simulation Strategy
Canetti, Goldreich, Goldwasser, and Micali (STOC 2000) introduced the notion of resettable zero-knowledge proofs, where the protocol must be zero-knowledge even if a cheating verifier can reset the prover and have several interactions in which the prover uses the same random tape. Soon afterwards, Barak, Goldreich, Goldwasser, and Lindell (FOCS 2001) studied the closely related notion of resettable soundness, where the soundness condition of the protocol must hold even if the cheating prover can reset the verifier to have multiple interactions with the same verifier's random tape. The main problem left open by this work was whether it is possible to have a single protocol that is simultaneously resettable zero knowledge and resettably sound. We resolve this question by constructing such a protocol. At the heart of our construction is a new non-black-box simulation strategy, which we believe to be of independent interest. This new strategy allows for simulators which "marry'' recursive rewinding techniques (common in the context of concurrent simulation) with non-black-box simulation. Previous non-black-box strategies led to exponential blowups in computational complexity in such circumstances, which our new strategy is able to avoid.
14201767
Stereo Correspondence with Occlusion Handling in a Symmetric Patch-Based Graph-Cuts Model
A novel patch-based correspondence model is presented in this paper. Many segment-based correspondence approaches have been proposed in recent years. Untextured pixels and boundaries of discontinuities are imposed with hard constraints by the discontinuity assumption that large disparity variation only happens at the boundaries of segments in the above approaches. Significant improvements on performance of untextured and discontinuity area have been reported. But, the performance near occlusion is not satisfactory because a segmented region in one image may be only partially visible in the other one. To solve this problem, we utilize the observation that the shared edge of a visible area and an occluded area corresponds to the discontinuity in the other image. So, the proposed model conducts color segmentation on both images first and then a segment in one image is further cut into smaller patches corresponding to the boundaries of segments in the other when it is assigned with a disparity. Different visibility of patches in one segment is allowed. The uniqueness constraint in a segment level is used to compute the occlusions. An energy minimization framework using graph-cuts is proposed to find a global optimal configuration including both disparities and occlusions. Besides, some measurements are taken to make our segment-based algorithm suffer less from violation of the discontinuity assumption. Experimental results have shown superior performance of the proposed approach, especially on occlusions, untextured areas, and near discontinuities
29420806
Strengthening QIM-Based Watermarking by Non-uniform Discrete Cosine Transform
Being extremely precise and at a low loss of perceptual quality, the attacks of value modification and optimized noise reduction still threaten the watermarking based on quantization index modulation (QIM). To resist them, the paper constructs a non-uniform discrete cosine transform (NDCT), and brings out an NDCT-QIM watermarking scheme, which embeds a watermark in a private NDCT domain with the parameters of NDCT as a secret key. The technique blinds the value modification by dispersing the attacking signal and changing its energy in the embedded domain. Because of the variable power spectrum of a watermark, the noise reduction becomes non-optimal. Some other advantages, including the ease of embedding, computational simplicity, etc., can also be acquired or maintained by the use of NDCT.
3145299
Resettable Zero Knowledge in the Bare Public-Key Model under Standard Assumption
In this paper we resolve an open problem regarding resettable zero knowledge in the bare public-key (BPK for short) model: Does there exist constant round resettable zero knowledge argument with concurrent soundness for $\mathcal{NP}$ in BPK model without assuming \emph{sub-exponential hardness}? We give a positive answer to this question by presenting such a protocol for any language in $\mathcal{NP}$ in the bare public-key model assuming only collision-resistant hash functions against \emph{polynomial-time} adversaries.
42696276
Concurrently Non-malleable Black-Box Zero Knowledge in the Bare Public-Key Model
In this paper we study the possibility of reducing the setup assumptions under which concurrent non-malleable zero knowledge protocol can be realized. A natural model choice is the bare public-key (BPK) model of [6], a model with very minimal setup assumptions. Our main contribution is to show in this model the following about constant-round concurrent non-malleable black-box zero-knowledge arguments. 
They can be constructed from any one-way function for any language in $\mathcal{NP}$. Here, our construction takes 5 rounds, and we can reduce it to a 4-round (round-optimal) argument under existence of one-way permutations. 
Under number-theoretic assumptions, they admit a time-efficient instantiation for some specific $\mathcal{NP}$ languages (e.g., all languages having efficient Σ protocols, for which we can implement our construction using only $\mathcal{O}(1)$ modular exponentiations). 
 
 
 
Compared to the non-black-box construction in a concurrent work of [OPV, ICALP 2008] in this model, our protocol (even the construction from one-way function) is significantly more time- and round-efficient and can be based on more general assumptions.