195706995
A Mobility-Aware Dynamic Database Caching Scheme for Wireless Mobile Computing and Communications
This paper describes a mobility-aware dynamic database caching scheme for wireless mobile computing and communications. A mobile-floating agent scheme is proposed, in which caching techniques are cognizant of the mobile nature of mobile users and the location-sensitive nature of mobile systems. The mobile-floating agent maintains a second class cache in the fixed network and employs Barbara’s “invalidation reports broadcasting” cache consistency strategies to maintain a dynamic cache consistent with the first class cache in the mobile client. The “invalidation reports broadcasting” scheme is combined with knowledge of the mobility behavior of each individual mobile user and broadcasts of invalidation reports only occur within the user’s mobility area. The evaluation results show that, for a large system (200 cells), this scheme can reduce the system cost by more than 87%, for even highly mobile users, compared with a fully replicated database system.
11364817
A class of mobile motion prediction algorithms for wireless mobile computing and communications
This paper describes a class of novel mobile motion prediction algorithms for supporting global mobile data accessing. Traditionally, mobility and routing management includes functions to passively keep track of the location of the users/terminals and to maintain connections to the terminals belonging to the system. To maintain uninterrupted high-quality service for distributed applications, it is important that a mobile system be more intelligent and can anticipate the change of the location of its user. We propose an aggressive mobility and routing management scheme, called predictive mobility management. A class of mobile motion prediction algorithms predicts the “future” location of a mobile user according to the user's movement history, i.e., previous movement patterns. By combining this scheme with mobility agent functions, the service and user routing data are actually pre-connected and pre-assigned at the locations to which the user is moving. Thus, the user can immediately receive service or data with virtually the same efficiency as at the previous location, i.e., without encountering a large “data structure handover” delay before service or data is available.
9736348
Some Problems on Factorizations with Constraints in Bipartite Graphs
Let G = (X, Y, E(G)) be a bipartite graph with vertex set V(G) = X ∪ Y and edge set E(G) and let g and f be two non-negative integer-valued functions defined on V(G) such that g(x) ≤ f(x) for each x ∈ V(G). A (g, f)-factor of G is a spanning subgraph F of G such that g(x) ≤ dF(x) ≤ f(x) for each x ∈ V(F); a (g, f)-factorization of G is a partition of E(G) into edge-disjoint (g, f)-factors. In this paper it is proved that every bipartite (mg + m - 1, mf - m + 1)-graph has (g, f)-factorizations randomly k-orthogonal to any given subgraph with km edges if k ≤ g(x) for any x ∈ V(G) and has a (g, f)-factorization k-orthogonal to any given subgraph with km edges if k - 1 ≤ g(x) for any x ∈ V(G) and that every bipartite (mg, m f)-graph has a (g, f)-factorization orthogonal to any given m-star if 0 ≤ g(x) ≤ f(x) for any x ∈ V(G). Furthermore, it is shown that there are polynomial algorithms for finding the desired factorizations and the results in this paper are in some sense best possible.
232914
Active and real-time functionalities for electronic brokerage design
In this position paper, we discuss an architecture for developing next generation electronic brokerages using active and real-time functionalities. These electronic brokerages support timeliness requirements and allow users to express complex preferences. User preferences can be conveniently captured as event-condition-action (ECA) rules. The design allows pro-active monitoring of user preferences and execution of actions in a timely manner. A proof-of-concept prototype is implemented using Java in the context of online trading. The prototype consists of three major components: rule validator, active rule manager and event monitor.
35387631
A lower bound on connectivities of matroid base graphs
Abstract The connectivity of a graph G and the corank of a matroid M are denoted by κ ( G ) and ϱ , respectively. It is shown that if a graph G is the base graph of a simple matroid M , then κ ( G )⩾2 ϱ and the lower bound of 2 ϱ is best possible.
8336028
Evaluation and optimization of clustering in gene expression data analysis
MOTIVATION
A measurement of cluster quality is needed to choose potential clusters of genes that contain biologically relevant patterns of gene expression. This is strongly desirable when a large number of gene expression profiles have to be analyzed and proper clusters of genes need to be identified for further analysis, such as the search for meaningful patterns, identification of gene functions or gene response analysis.


RESULTS
We propose a new cluster quality method, called stability, by which unsupervised learning of gene expression data can be performed efficiently. The method takes into account a cluster's stability on partition. We evaluate this method and demonstrate its performance using four independent, real gene expression and three simulated datasets. We demonstrate that our method outperforms other techniques listed in the literature. The method has applications in evaluating clustering validity as well as identifying stable clusters.


AVAILABILITY
Please contact the first author.
171789
A database and tool, IM Browser, for exploring and integrating emerging gene and protein interaction data for Drosophila
BackgroundBiological processes are mediated by networks of interacting genes and proteins. Efforts to map and understand these networks are resulting in the proliferation of interaction data derived from both experimental and computational techniques for a number of organisms. The volume of this data combined with the variety of specific forms it can take has created a need for comprehensive databases that include all of the available data sets, and for exploration tools to facilitate data integration and analysis. One powerful paradigm for the navigation and analysis of interaction data is an interaction graph or map that represents proteins or genes as nodes linked by interactions. Several programs have been developed for graphical representation and analysis of interaction data, yet there remains a need for alternative programs that can provide casual users with rapid easy access to many existing and emerging data sets.DescriptionHere we describe a comprehensive database of Drosophila gene and protein interactions collected from a variety of sources, including low and high throughput screens, genetic interactions, and computational predictions. We also present a program for exploring multiple interaction data sets and for combining data from different sources. The program, referred to as the Interaction Map (IM) Browser, is a web-based application for searching and visualizing interaction data stored in a relational database system. Use of the application requires no downloads and minimal user configuration or training, thereby enabling rapid initial access to interaction data. IM Browser was designed to readily accommodate and integrate new types of interaction data as it becomes available. Moreover, all information associated with interaction measurements or predictions and the genes or proteins involved are accessible to the user. This allows combined searches and analyses based on either common or technique-specific attributes. The data can be visualized as an editable graph and all or part of the data can be downloaded for further analysis with other tools for specific applications. The database is available at http://proteome.wayne.edu/PIMdb.htmlConclusionThe Drosophila Interactions Database described here places a variety of disparate data into one easily accessible location. The database has a simple structure that maintains all relevant information about how each interaction was determined. The IM Browser provides easy, complete access to this database and could readily be used to publish other sets of interaction data. By providing access to all of the available information from a variety of data types, the program will also facilitate advanced computational analyses.