6479052
Data Analysis for Query Processing
Data analysis is needed in connection with query processing, to produce data summary information in the form of rules or assertions that allow semantic query optimisation or direct query answering without consulting the data itself. The goal of an intelligent analyser in this context is to produce robust rules, stable in the presence of data changes, which allow easy rule maintenance as data changes, and provide rapid query reformulation, refutation or answering. It must also limit the rule set to rules useful for query processing.
34571067
Data Extraction from Web Database Query Result Pages via Tagsets and Integer Sequences
The World Wide Web is a collection of databases as well as web sites. Databases associated with web sites provide public access via query forms on web pages. They constitute an enormous repository of searchable data on an extremely diverse collection of subjects, ranging from multimedia collections through archives of subject-specific data to current information such as currency conversion or interest rates and news or weather reports. Many interesting and valuable Database Applications could be developed if these databases were easily and reliably accessible to programs. The difficulty in extracting data is the number of different web page formats and the tendency to change format suddenly. A rapid page analysis and wrapper creation system is needed to generate and maintain a data extraction facility for any required web sites. This important goal has been the subject of substantial recent research, modelling the web results page in various ways. The purpose of the current paper is to introduce a new method for rapid page analysis using the recurrence patterns of tagSet occurrence in the page.
6242831
Distributing the Derivation and Maintenance of Subset Descriptor Rules
This draft paper describes a solution to the rule maintenance problem for data descriptor rules derived from data that may subsequently change. The method utilises any available computers in the local area network, to derive and maintain rule sets.
14933774
Using a Network of Workstations to Enhance Database Query Processing Performance
Query processing in database systems may be improved by applying parallel processing techniques. One reason for improving query response time is to support the increased number queries when databases are made accessible from the Internet.
11146897
Constructing Inter-relational Rules for Semantic Query Optimisation
Semantic query optimisation is the process by which a user query is transformed into a set of alternative queries each of which returns the same answer as the original. The most efficient of these alternatives is then selected, for execution, using standard cost estimation techniques. The query transformation process is based on the use of semantic knowledge in the form of rules which are generated either during the query process itself or are constructed according to defined heuristics. Previous research has tended to focus on constructing rules applicable to single relations and does not take advantage of the additional semantic knowledge, inherent in most databases, associated with relational joins. Our paper seeks to address this weakness by showing how the rule derivation process may be extended to the generation of inter-relational rules using an approach based on inductive learning.
9837737
Attribute-Pair Range Rules
This paper examines the properties of metadata in the form of IF THEN rules which contain two predicates on attributes of a relational database table. For example: a(15. 30) ⟹ d(243. 271), which means “if the value of attribute ‘a’ in a tuple is in the range 15 to 30 then the value of attribute ‘d’ will be in the range 243 to 271.” Metadata of this kind is useful in Semantic Query Optimisation and Remote Cache Management. The two predicates (antecedent and consequent) in each rule are Selection Conditions or constraints of the type found in database queries. Each condition therefore denotes a subset of a database table. Rules can be cascaded, using subrange containment as the link between successive rules. The set of rules can therefore be regarded as a set of edges in a Condition Dependency Graph, and using the rule-set is path discovery in the graph. The purpose of the current paper is to introduce some of the properties of attribute-pair range rules.
12209685
Measurement driven deployment of a two-tier urban mesh access network
Multihop wireless mesh networks can provide Internet access over a wide area with minimal infrastructure expenditure. In this work, we present a measurement driven deployment strategy and a data-driven model to study the impact of design and topology decisions on network-wide performance and cost. We perform extensive measurements in a two-tier urban scenario to characterize the propagation environment and correlate received signal strength with application layer throughput. We find that well-known estimates for pathloss produce either heavily overprovisioned networks resulting in an order of magnitude increase in cost for high pathloss estimates or completely disconnected networks for low pathloss estimates. Modeling throughput with wireless interface manufacturer specifications similarly results in severely underprovisioned networks. Further, we measure competing, multihop flow traffic matrices to empirically define achievable throughputs of fully backlogged, rate limited, and web-emulated traffic. We find that while fully backlogged flows produce starving nodes, rate-controlling flows to a fixed value yields fairness and high aggregate throughput. Likewise, transmission gaps occurring in statistically multiplexed web traffic, even under high offered load, remove starvation and yield high performance. In comparison, we find that well-known noncompeting flow models for mesh networks over-estimate network-wide throughput by a factor of 2. Finally, our placement study shows that a regular grid topology achieves up to 50 percent greater throughput than random node placement.
15957762
Sensor networks and grid middleware for laboratory monitoring
By combining automatic environment sensing and experimental data collection with broker based messaging middleware, a system has been produced far the real-time monitoring of experiments whilst away from the lab. Changes in the laboratory environment are encapsulated as simple messages, which are published using an MQTT compliant broker. Clients subscribe to the MQTT stream, and perform a data transform on the messages; this may be to produce a user display or to change the format of the message for republishing. For example, an MQTT client written for the Java MIDP platform can be run on a smart-phone with a GPRS Internet connection, freeing us from the constraints of the network. We present an overview of the technologies used, and how these are helping chemists make the best use of their time
28156050
An Introduction to Hyperarithmetical Functions
14389185
A Machine-Oriented Logic Based on the Resolution Principle
:tb.~tract. Theorem-proving on the computer, using procedures based on the fund~mental theorem of Herbrand concerning the first-order predicate etdeulus, is examined with ~ view towards improving the efticieney and widening the range of practical applicability of these procedures. A elose analysis of the process of substitution (of terms for variables), and the process of t ruth-funct ional analysis of the results of such substitutions, reveals that both processes can be combined into a single new process (called resolution), i terating which is vastty more ef[ieient than the older cyclic procedures consisting of substitution stages alternating with truth-functional analysis stages. The theory of the resolution process is presented in the form of a system of first<~rder logic with .just one inference principle (the resolution principle). The completeness of the system is proved; the simplest proof-procedure based oil the system is then the direct implementation of the proof of completeness. Howew~r, this procedure is quite inefficient, ~nd the paper concludes with a discussion of several principles (called search principles) which are applicable to the design of efficient proof-procedures employing resolution as the basle logical process.
5441653
Integrating targeted cycle-time reduction into the capital planning process
This paper describes the development and application of an integrated static capacity and dynamic simulation analysis methodology for purchasing equipment capacity. The goal of the study is to address targeted cycle time objectives in a start up recording head wafer manufacturing facility at Seagate Technology, Minneapolis, MN. The short product cycle time, coupled with the competitive nature of the disc drive industry, has made cycle time reduction one of the most important objectives of production capacity planning. This paper describes an equipment procurement strategy in which static capacity analysis is used to identify an initial equipment set with a low slack capacity variable on each tool group. Simulation analysis is then used to identify the critical tool groups that contribute to cycle time delays. The Seagate Industrial Engineering team used the simulation analysis tool Factory Explorer(R) from Wright, Williams and Kelly to perform the cycle time reduction analysis. This targeted approach is compared to the traditional static capacity planning approach of globally applying reserve capacity buffers of 20% or more to achieve the same cycle time reduction goal. Overall, the targeted approach has proven to be efficient in terms of minimizing capital equipment expenditures and also effective on the factory floor.