206817675
Independence numbers of graphs and generators of ideals
This article investigates the generators of certain homogeneous ideals which are associated with graphs with bounded independence numbers. These ideals first appeared in the theory oft-designs. The main theorem suggests a new approach to the Clique Problem which isNP-complete. This theorem has a more general form in commutative algebra dealing with ideals associated with unions of linear varieties. This general theorem is stated in the article; a corollary to it generalizes Turán’s theorem on the maximum graphs with a prescribed clique number.
1532090
Fast knockout algorithm for self-route concentration
Concentration has been a popular technique for resolving contention in switching. In particular, self-route concentration is useful inside ATM switching fabrics in many ways. This paper presents an efficient algorithm for the construction of self-route concentrators from multi-stage cascades of 2x2 sorters, where the main criterion on the complexity is the number of stages in the cascade. The algorithm extensively generalizes the existing Fast Knockout algorithm and mixes in some k-sorting technique. The result includes a best known construction of m-to-n self-route concentrator for all m and n within the practical range.
45808479
Recursive Construction of Distributors by Merging
2426410
Network information flow
We introduce a new class of problems called network information flow which is inspired by computer network applications. Consider a point-to-point communication network on which a number of information sources are to be multicast to certain sets of destinations. We assume that the information sources are mutually independent. The problem is to characterize the admissible coding rate region. This model subsumes all previously studied models along the same line. We study the problem with one information source, and we have obtained a simple characterization of the admissible coding rate region. Our result can be regarded as the max-flow min-cut theorem for network information flow. Contrary to one's intuition, our work reveals that it is in general not optimal to regard the information to be multicast as a "fluid" which can simply be routed or replicated. Rather, by employing coding at the nodes, which we refer to as network coding, bandwidth can in general be saved. This finding may have significant impact on future design of switching systems.
39573562
Binary Trees and Uniform Distribution of Traffic Cutback
Abstract This article introduces the notion of the External Left Length (ELL) of binary trees, which is analogous to the notion of the External Path Length (EPL), and derives theorems about the ELL which correspond to well-known facts about the EPL. Results are applied to the analysis of the optimization of an algorithm for the smooth traffic cutback in data communication.
8736073
Using Feature-Oriented Analysis to Recover Legacy Software Design for Software Evolution
Most design recovery approaches start from analysing source code. Nonetheless, it is very difficult to get adequate design information only depending on source code. Additional available information is required and Feature Oriented Analysis (FOA) is a way to reach this aim. FOA addresses the understanding of features in software systems and defines mechanisms for carrying a feature from the problem domain into the solution domain. Using feature as the first-class entity for software evolution can improve program comprehension and design recovery. In this paper, an approach is proposed to recover software design based on the feature model, which is a kind of legacy system knowledge. The features will first be located and mapped to the implementation module so that feature-oriented components can be identified and retrieved, and then, through the analysis of the feature relations, the design model of legacy system can be recovered and used for the future evolution.
14536606
On the security of an image encryption method
The security of digital images has attracted much attention, and many different image encryption methods have been proposed. Yen and Guo (see Proc. IEEE Workshop Signal Processing Systems, p.430-37, 1999) proposed a novel image encryption algorithm called BRIE (bit recirculation image encryption). This paper points out that BRIE is not secure enough from strict cryptographic viewpoint. It has been found that some defects exist in BRIE, and a known/chosen-plaintext attack can break BRIE with only one known/chosen plain-image. Experiments are made to verify the defects of BRIE and the feasibility of the attack.
16413633
Feature analysis for service-oriented reengineering
Web services together with service-oriented architectures (SOA) are playing an important role in the future of distributed computing, significantly impacting software development and evolution. With the adoption to Web services technology, more and more existing non-service-oriented software systems turn to be legacy systems. They require a service-oriented reengineering process in order to survive in service-oriented computing environment. If the reengineering goal is to expose the services of a single object or any underlying function-oriented middleware, many problems will arise including semantic mismatches, service granularity issues and state management. Attempting to masquerade software assets from a lower level of abstraction can often cause significant mismatch and exposure problems. In this paper, by using feature analysis, an approach to supporting service-oriented reengineering is presented. Service identification and packaging process are performed and resulted into a service delegation.
16159507
A scenario-based stochastic programming approach for technology and capacity planning
In response to market pressures resulting in increased competition, product proliferation and greater customization, firms in many industries have adopted modern technologies to provide operational flexibility on several dimensions. In this paper, we consider the role of product mix flexibility, defined as the ability to produce a variety of products, in an environment characterized by multiple products, uncertainty in product life cycles and dynamic demands. Using a scenario-based approach for capturing the evolution of demand, we develop a stochastic programming model for determining technology choices and capacity plans. Since the resulting model is likely to be large and may not be easy to solve with standard software packages, we develop a solution procedure based on augmented Lagrangian method and restricted simplicial decomposition. The scope of our approach for deriving context specific managerial insights is illustrated by the results of limited computations. Finally, we demonstrate the versatility of our approach by deriving a special case of the general model to address some tactical issues related to new product introduction.
36253673
A fuzzy goal programming approach to multi-objective optimization problem with priorities
Abstract In goal programming problem, the general equilibrium and optimization are often two conflicting factors. This paper proposes a generalized varying-domain optimization method for fuzzy goal programming (FGP) incorporating multiple priorities. According to the three possible styles of the objective function, the varying-domain optimization method and its generalization are proposed. This method can generate the results consistent with the decision-maker (DM)’s expectation, that the goal with higher priority may have higher level of satisfaction. Using this new method, it is a simple process to balance between the equilibrium and optimization, and the result is the consequence of a synthetic decision between them. In contrast to the previous method, the proposed method can make that the higher priority achieving the higher satisfactory degree. To get the global solution of the nonlinear nonconvex programming problem resulting from the original problem and the varying-domain optimization method, the co-evolutionary genetic algorithms (GAs), called GENOCOPIII, is used instead of the SQP method. In this way the DM can get the optimum of the optimization problem. We demonstrate the power of this proposed method by illustrative examples.