Automated Knowledge Acquisition in a Neural Network–Based Decision Support System for Incomplete Database Systems

Abstract: A neural network–based decision support system has been designed and simulated to be used as a filter to improve the system performance of large incomplete databases enhanced with maybe algebra. To train the network, a knowledge-acquisition module equipped with a fuzzy logic technique was used to automatically generate a set of training pairs according to the semantics of the underlying database, the specific characteristics of the user query, and user requirements. Based on the notion of relative graded membership, a fuzzy logic–based controller was used to monitor and measure the quality of each training pattern as a means to generate a set of "good" training pairs. Finally, the proposed scheme has been simulated and analyzed to determine the effectiveness of the automatic training pairs generation process.     

General-purpose systolic arrays

The extension of systolic array architecture from fixed- or special-purpose architectures to general-purpose, SIMD (single-instruction stream, multiple-data stream), MIMD (multiple-instruction stream, multiple-data stream) architectures, and hybrid architectures that combine both commercial and FPGA (field-programmable gate array) technologies is chronicled. The authors present a taxonomy for systolic organizations, discuss each architecture's methods of exploiting concurrencies, and compare performance attributes of each. The authors also describe a number of implementation issues that determine a systolic array's performance efficiency, such as algorithms and mapping, system integration through memory subsystems, cell granularity, and extensibility to a wide variety of topologies     

A 16-Kbit Θ-search associative memory

The design of a high-capacity Θ-search associative memory (Θ∈{<,>,⩽,⩾,=≠}) is presented. PSPICE simulation and layouts show that the proposed Θ-search associative memory chip consisting of 256 words, each 64-b long, can fit on a 13.5-mm×9.5-mm chip. It can perform maskable Θ-search operations over its contents in 110 ns     

Transaction processing in mobile, heterogeneous database systems

As technological advances are made in software and hardware, the feasibility of accessing information "any time, anywhere" is becoming a reality. Furthermore, the diversity and amount of information available to a given user is increasing at a rapid rate. In a mobile computing environment, a potentially large number of users may simultaneously access the global data; therefore, there is a need to provide a means to allow concurrent management of transactions. Current multidatabase concurrency control schemes do not address the limited bandwidth and frequent disconnection associated with wireless networks. This paper proposes a new hierarchical concurrency control algorithm. The proposed concurrency control algorithm, v-lock, uses global locking tables created with semantic information contained within the hierarchy. The locking tables are used to serialize global transactions, detect and remove global deadlocks. Additionally, data replication, at the mobile unit, is used to limit the effects of the restrictions imposed by a mobile environment. The replicated data provides additional availability in case of a weak connection or disconnection. Current research has concentrated on page and file-based caching or replication schemes to address the availability and consistency issues in a mobile environment. In a mobile, multidatabase environment, local autonomy restrictions prevent the use of a page or file-based data replication scheme. This paper proposes a new data replication scheme to address the limited bandwidth and local autonomy restrictions. Queries and the associated data are cached at the mobile unit as a complete object. Consistency is maintained by using a parity-based invalidation scheme. A simple prefetching scheme is used in conjunction with caching to further improve the effectiveness of the proposed scheme. Finally, a simulator was developed to evaluate the performance of the proposed algorithms. The simulation results are presented and discussed.     

Energy-efficient wireless information retrieval

In this paper, we propose an adaptive application-driven power management (AADPM) protocol for wireless information retrieval applications within the IEEE 802.11b infrastructure WLAN environment. Our goal is to minimize energy consumption while achieving low round trip time delay. We discuss the protocol and evaluate its effectiveness using the network simulator NS2. We also draw horizontal comparisons among a variety of PM methods reported in the literature. Experimental results show that, compared to the power save mode supported by 802.11b, AADPM reduces the network interface card energy consumption by 52% while only introducing 3% RTT delay.     

A hybrid scheme for processing data structures in a dataflowenvironment

The asynchronous nature of the dataflow model of computation allows the exploitation of maximum inherent parallelism in many application programs. However, before the dataflow model of computation can become a viable alternative to the control flow model of computation, one has to find practical solutions to some problems such as efficient handling of data structures. The paper introduces a new model for handling data structures in a dataflow environment. The proposed model combines constant time access capabilities of vectors as well as the flexibility inherent in the concept of pointers. This allows a careful balance between copying and sharing to optimize the storage and processing overhead incurred during the operations on data structures. The mode] is compared by simulation to other data structure models proposed in the literature, and the results are good     

Threaded implant design criteria

The in vivo performance of multiparticulate sustained-release diltiazem preparations [HER-SR(A,B,C)] coated with water-insoluble polymer (ethylcellulose), to control the in vitro dissolution rate, was evaluated in dogs. With a decrease in dissolution rate, HER-SR maintained sustained-release characteristics, although the bioavailability decreased slightly. The bioavailability of HER-SR(A,B,C) was comparable with that of a conventional diltiazem tablet (HER). Plasma diltiazem concentrations for the HER-SR preparations were analyzed with a two-fraction absorption model and the pharmacokinetic characteristics were discussed. From the results, it was considered that HER-SR(B) preparation had desirable pharmacokinetic characteristics as sustained-release diltiazem preparations. The absorption site of the slow-release component of HER-SR(B) in the gastrointestinal tract was examined. Almost all of the component had reached the colon within 5 h of administration, the diltiazem content remaining in the component being approximately 60% of the initial amount. Thus, it was shown that the HER-SR(B) preparation had particular absorption characteristics that resulted in the colon being the part of the gastrointestinal tract most receptive to its release. In vivo release profiles of diltiazem from the HER-SR(B) preparation were calculated by the Wagner-Nelson method, and in vitro and in vivo release profiles of HER-SR(B) were further analyzed with a two-fraction release equation. A close correlation of in vitro and in vivo release profiles of HER-SR(B) was found.     

A taxonomy and current issues in multidatabase systems

A taxonomy of global information-sharing systems is presented, and the way in which multidatabase systems fit into the spectrum of solutions is discussed. The taxonomy is used as a basis for defining multidatabase systems. Issues associated with multidatabase systems are reviewed. Two major design approaches for multidatabases, global schema systems and multidatabase language systems, are described. Existing multidatabase projects and areas for further research are also discussed     

Guest Editors's Introduction: Multimedia Systems,Mobile Computing and Global Information Sharing

Multimedia Tools and Applications -     

Power-aware data retrieval protocols for indexed broadcast parallel channels

In pervasive and mobile computing environments, “timely and reliable” access to public data requires methods that allow quick, efficient, and low-power access to information to overcome technological limitations of wireless communication and access devices. The literature suggests broadcasting (one-way communication) as an effective way to disseminate the public data to mobile devices. Within the scope of broadcasting, the response time and energy consumption of retrieval methods have been used as the performance metrics for measuring the effectiveness of different access methods. The hardware and architecture of the mobile units offer different operational modes that consume different energy levels. Along with these architectural and hardware enhancements, techniques such as indexing, broadcasting along parallel channels, and efficient allocation and retrieval protocols can be used to minimize power consumption and access latency.In general, the retrieval methods attempt to determine the optimal access pattern for retrieving the requested data objects on parallel broadcast channels. The employment of heuristics provides a methodology for such ideal path planning solutions. Using informative heuristics and intelligent searches of an access forest can provide a prioritized cost evaluation of access patterns for requested data objects and, hence, an optimal path for the access of requested data on broadcast air channels.This paper examines two scheduling methods that along with a set of heuristics generate and facilitate the access patterns for retrieving data objects in the presence of conflicts in an indexed parallel broadcast channel environment. A simulation of the proposed schemes is presented for analyzing the relationship between response time and power consumption.