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.
955470
Improved Data Retrieval Using Semantic Transformation
Semantic query optimisation uses knowledge about properties of the data, represented as a set of subset descriptor rules, to transform a query into another form that can be executed in a more efficient manner but still yields the same result as the original query. Commonly this ’semantic knowledge’ in the form of rules is generated either during the query process itself or else is constructed in advance according to defined heuristics. Over a period of time the rule set may, therefore, become very large and the number of semantically equivalent queries that may be derived rises exponentially. Each rule use creates a new equivalent query. The problem is to identify one near optimal alternative query in a time that is minimal and also short relative to the overall query execution time. In this paper we propose a method for measuring the effectiveness of each rule and present a fast algorithm which selects the most cost effective transformations to directly yield the optimal alternative query. Experiments carried out on a large publicly available dataset show worthwhile savings using the approach.
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.
27757665
Exploiting Parallelism in Primitive Operations on Bulk Data Types
Structures based on tuples may be used to represent the common bulk data types found in symbolic applications. Few languages support primitive operations that handle such structures explicitly, and fewer support them as persistent objects. Even when relevant data types are accommodated at the language level, implementations are very inefficient because of the lack of underlying systems architecture support. The result is over-complex software and missed opportunities to exploit the inherent data-parallelism present in these structures. In this paper we propose a representational framework, a repertoire of primitive operations, and a systems architecture for handling the bulk data types relevant to (deductive) databases and knowledge-based applications. We indicate the opportunities for exploiting inherent parallelism, and briefly report on prototype novel parallel hardware which supports the structure primitives.
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.
6898048
Supporting manufacturing with simulation: model design, development, and deployment
In this paper, we identify and discuss the features we believe are key to the successful use of simulation as a manufacturing support tool. The discussion begins with three sample projects drawn from the authors' industrial and consulting experiences. Using these projects as motivation, we discuss the ideal project lifecycle model design, development, and deployment. For model design, we emphasize the importance of a clear and consistent specification, articulated in a written document. This specification should identify project customers, goals, and deliverables. We next review a range of model development options, stressing the existence of many non-simulation alternatives. We also discuss methods for model verification and validation. Finally, we consider the difficulties of model deployment, including simulation output analysis, data maintenance, and model integration. We close with several suggestions on how best to present simulation results to a management audience.
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.
40861592
Definability and Decision Problems in Arithmetic
In this paper, we are concerned with the arithmetical definability of certain notions of integers and rationals in terms of other notions. The results derived will be applied to obtain a negative solution of corresponding decision problems. In Section 1, we show that addition of positive integers can be defined arithmetically in terms of multiplication and the unary operation of successor S (where Sa = a + 1). Also, it is shown that both addition and multiplication can be defined arithmetically in terms of successor and the relation of divisibility | (where x|y means x divides y ).
2266734
Procedures for Integrating Knowledge in a Speech Understanding System
T h i s paper d e s c r i b e s t h e p r o c e d u r e s f o r i n t e g r a t i n g knowledge f rom d i f f e r e n t s o u r c e s i n t h e SRI speech u n d e r s t a n d i n g s y s t e m . A language d e f i n i t i o n sys tem c o o r d i n a t e s — a t t h e ph rase l e v e l — i n f o r m a t i o n f rom s y n t a x , s e m a n t i c s and d i s c o u r s e i n t h e cou rse o f t h e i n t e r p r e t a t i o n o f a n u t t e r a n c e . The sys tem e x e c u t i v e uses t h e s e c o n t e x t u a l c o n s t r a i n t s i n a s s i g n i n g p r i o r i t i e s t o a l t e r n a t i v e i n t e r p r e t a t i o n s , c o m b i n i n g t o p d o w n , b o t t o m u p , and b i d i r e c t i o n a l s t r a t e g i e s a s r e q u i r e d E x p e r i m e n t a l r e s u l t s t h a t d e m o n s t r a t e t h e e f f e c t i v e n e s s o f c o n t e x t c h e c k i n g a r e d i s c u s s e d .
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