PRISM :: Browsing by Author "Bradley, James"

Browsing by Author "Bradley, James"

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Open Access
A prototype front-end for a declarative object-relational database language employing natural quantifiers and genitive relations
(1995) Rata, Carmen-Daniela; Bradley, James
Open Access
CO-RELATIONSHIPS, LEVELS OF SIGNIFICANCE AND THE SOURCE OF THE CONNECTION TRAPIN RELATIONAL DATA BASES
(1986-12-01) Bradley, James
We propose to attribute one or more precisely defined levels of semantic significance to every co-relationship in a relational data base. We also propose a precise definition of a relationship, and define a co-relationship as one of the two non trivial primitive relationship types, that is, a co-relationship occurs between two relations when a relationship relation can be formed with a single join on join attributes of the two relations that are neither primary nor candidate key attributes. It is shown that a co-relationship will give rise to a connection trap when users assume either a level of significance for the co-relationship that is too high, or which is correct but not supported by the data in the data base. Furthermore, anticipation by data base designers of user assumptions about levels of significance for co-relationships, and consequent data base modifications to avoid connection traps, will be very much a matter of judgement of user behavioral probabilities, thus rendering both automated data base design algorithms and universal relation generation algorithms prone to failure.
Open Access
A COMPLETE L-SYSTEM SPECIFICATION FOR GENERATING AN EXACT SELF-AFFINE GROWTH/COLLAPSE FUNCTION WITH A RANDOM-WALK SCALING PROPERTY
(1993-06-01) Bradley, James
The existence of at least four exact self-affine time functions, called E5:3 functions, that allow for an infinite number of exact replications of 12345abc structures, is demonstrated. These E5:3 functions are defined by algorithms and have no derivative anywhere. One of these E5:3 functions, called the standard E5:3 function, has the property of scaling like a random walk. This function also depends on the Golden Mean and rotates congruently with the Golden Spiral. A complete L-System specification for generating the standard E5:3 function is presented.
Open Access
A COMPLETE L-SYSTEM SPECIFICATION FOR GENERATING AN EXACT SELF-AFFINE TIME FUNCTION WITH A RANDOM-WALK SCALING PROPERTY
(1992-12-01) Bradley, James
An exact self-affine time function, unlike a fractal in two-dimensional space, replicates exactly when scaled by differing ratios in the amplitude and time axes. A statistical self affine time function replicates only statistically when scaled by differing ratios in the amplitude and time axis, the best known example being a random walk, where the time scaling factor is the square of the amplitude scaling factor. The existence of at least four exact self affine time functions, called E53 functions, that allow for an infinite number of exact replications of 12345abc structures, is demonstrated. These E53 functions are defined by algorithms and have no derivitive anywhere. One of these E53 functions, called the standard E53 function, has the property of scaling like a random walk. A complete L-System specification for generating the standard E53 function is presented.
Open Access
COOL CONCEPTS AND SEMANTICS FOR DEFINITION, CONCENTRATION AND MANIPULATION OF COMPOSITE OBJECTS IN AN RELATIONAL DATA BASE
(1993-03-01) Bradley, James
COOL is a composite object-oriented declarative language for use as an extension to SQL with relational databases that have a distinct object orientation. COOL is unique in that it permits unambiguous specification and quantification of relationships by means of a construct called a genitive relation. The notion of composite object concentration with COOL is also introduced. The paper describes advanced COOL constructs, for which there are no SQL equivalents, for definition and extraction of composite objects from a relational data base. These constructs permit specification, concentration and manipulation of composite objects of great complexity. It is also shown how COOL uses these constructs with the inheritance aspects of generalization or IS-A type hierarchies.
Open Access
COOL: A COMPOSITE OBJECT ORIENTED LANGUAGE FOR OBJECT-ORIENTED RELATIONAL DATA BASES
(1993-03-01) Bradley, James
COOL is a composite object-oriented declarative data base language for use with relational data bases. COOL uses a construct called a genitive relation to enable unambiguous specification and quantification, both conventional and natural, of relationships. A genitive relation is used in a manner corresponding to the genitive case with noun objects in natural language. Instead of formal genitive relation name syntax, a genitive case alias can be used to promote ease of expression construction. COOL expressions are similar in construct to the equivalent natural language expressions. COOL can manipulate independent entity structures, both hierarchical and network, and generalization or IS-A type hierarchies. COOL is proposed as an extension to SQL, for use where a relational data base has a distinct object-orientation.
Open Access
AN EFFICIENT MODULARIZED DATABASE STRUCTURE FOR A HIGH-RESOLUTION COLUMN-GRIDDED MARS GLOBAL TERRAIN DATABASE
(1997-12-01) Bradley, James
This paper discusses a modularized design for a Mars Global Terrain Database. The design provides for elevation data with respect to a triaxial ellipsoidal reference datum developed for Mars by USGS. Terrain data is recorded for 1-second of arc grid elements over the surface of Mars. A 400 Gigabyte column-gridded relation called Terrain contains the surface terrain data. Data for Terrain is expected in 1999-2000 from the Mars Global Surveyor satellite currently in initial polar orbit around Mars. Each tuple of Terrain contains data for a N-S column-grid of 900 1-second grid elements. There is thus a set of tuples per 1-degree rectangle, with the number of tuples per set decreasing with the cosine of latitude. Surface resolution is a uniform 16.5 meters everywhere with a 1-second grid. The design constrains tuple sizes in Terrain to permit efficient blocking and manipulation of the records of the underlying storage file. Terrain contains a virtual-attribute function for geodetic computations relating to the triaxial ellipsoidal reference datum. The database also relates Mars feature-type relations to Terrain. Terrain's gridded structure is transparent to users writing SQL expressions to retrieve Terrain data on the basis of specific features. Many different distinct feature-type relations can be included. At least two of these are participate in recursive relationships. The design also allows attachment of additional feature-type relations in a modular manner, correctly related to Terrain, without affecting the contents of Terrain.
Open Access
AN EFFICIENT MODULARIZED DATABASE STRUCTURE FOR A HIGH-RESOLUTION COLUMN-GRIDDED MARS GLOBAL TERRAIN DATABASE
(1998-11-01) Bradley, James
This paper discusses a modularized design for a Mars Global Terrain Database. The design provides for elevation data with respect to a triaxial ellipsoidal reference datum developed for Mars by USGS. Terrain data is recorded for 1-second of arc almost square grid elements over the surface of Mars. A 2000-Gigabyte column-gridded relation called Terrain contains the surface terrain data. Data for Terrain is expected in 1999-2000 from the Mars Global Surveyor satellite currently in initial polar orbit around Mars. Each tuple of Terrain contains data for a N-S column-grid of 900 1-second grid elements. There is thus a set of tuples per 1-degree rectangle, with the number of tuples per set decreasing with the cosine of latitude. Surface resolution is 16.5 meters or better. The design constrains tuple sizes in Terrain to permit efficient blocking and manipulation of the records of the underlying storage file. Terrain contains a virtual-attribute function for geodetic computations relating to the triaxial ellipsoidal reference datum. The database also relates Mars feature-type relations to Terrain. Terrain's gridded structure is transparent to users writing SQL expressions to retrieve Terrain data on the basis of specific features. Many different distinct feature-type relations can be included. At least two of these participate in recursive relationships. The design also allows attachment of additional feature-type relations in a modular manner, correctly related to Terrain, without affecting the contents of Terrain. The design is intended to enable efficient exploration of the planet at all levels of scale.
Open Access
ELECTROLYTIC AND OTHER GRODECS AS ACCURATE NEURON MODELS FOR NEURAL NETWORKS
(1997-12-01) Bradley, James
A grodec is a versatile entity with switched growth-decay pressure behavior. Grodecs can be used to construct both grodec stack machines and accurate neuron models. A grodec needs an operating fluid, and when this fluid involves ions, pressure changes are voltage changes. A single reservoir-based grodec has the pressure-change properties of a short section of biological membrane, and can give rise to generalized, pressure-change action potentials. A pair of appropriately coupled reservoir-based grodecs can generate a much sharper action potential than can a single grodec. The action potentials from a single reservoir-based electrolytic grodec based on Na+, and from a coupled electrolytic grodec pair with one grodec based on Na+ and the other based on K+, are analysed in detail. So close is the voltage-switching mechanism and behavior of the coupled electrolytic grodec pair to those of a neuron with dual Na+ and K+ ion switching, that it is concluded that a neuron membrane can be regarded conceptually as a Na+ grodec coupled to a K+ grodec. Grodecs of any kind can be coupled in excitory or inhibitory manner to form neural nets.
Open Access
EXTENDED RELATIONAL ALGEBRA FOR REDUCTION OF NATURAL QUANTIFIER EXPRESSIONS
(1993-07-01) Bradley, James
An extended relational algebra has been developed. This extended algebra is suitable for reduction of expressions written in the natural quantifier language COOL. The algebra consists of conventional operations plus a group select, a subgroup select and possibility join operation. The group select operation selects each group of related tuples where a quantity of the group obeys a condition. The subgroup-select operation selects each group of related tuples where a quantity of a subgroup of the group obeys a condition. The possibility join of relation R1 with relation R2 regenerates relation R1 but with each tuple having a logical attribute p concatenated, with p true where the R1 tuple could have been joined to an R2 tuple, otherwise p false. Generalized algebra routines for generalized COOL expressions are presented.
Open Access
EXTENDED RELATIONAL ALGEBRA FOR REDUCTION OF NATURAL QUANTIFIER COOL EXPRESSIONS
(1994-05-01) Bradley, James
An extended relational algebra has been developed. This extended algebra is suitable for reduction of expressions written in the object-oriented natural quantifier language COOL. The algebra consists of conventional operations plus a group select, a subgroup select and possibility join operation. The group select operation selects each group of related tuples where a quantity of the group obeys a condition. The subgroup select operation selects each group of related tuples where a quantity of a subgroup of the group obeys a condition. The possibility join of relation R1 with relation R2 regenerates relation R1 but with each tuple having a logical attribute p concatenated, with p true where the R1 tupple could have been joined to an R2 tuple, otherwise p false. Generalized algebra routines for generalized COOL expressions are presented.
Open Access
FIVE EQUATIONS RELATING THROUGHPUT CAPACITY TO SYSTEM RESOURCES AND RISK FOR ALL AGENT DIRECTED NON-GROWTH SYSTEMS
(1999-06-01) Bradley, James
Five equations for system throughput capacity (1), governing all non-growth, agent-directed systems are proposed and justified. Each equation covers a specific system aspect. Any two or more of the equations can be combined. The equations are: a 'system sharing equation' that shows how (1) can be maintained by reducing resources and increasing resource-sharing procedure complexity, or vice versa. A 'basic risk equation' that shows how expected (1) increases [decreases] linearly with positive [negative] risk of loss of (1) in efficient environments. A 'preventive-resources risk equation' that shows how (1) is improved by application of risk-preventing resources to reduce known risk. A 'precautionary-procedure risk equation' that shows how (1) is improved by use of precautionary procedures to reduce known risk. A 'monitoring-procedure risk equation' that shows how (1) is improved by use of a real-time monitoring procedure and risk-meaningful database to detect unknown risk and reduce it with precautionary response procedures. The conventional 'standard deviation risk measure with respect to mean' from financial systems may be used, but a proposed new measure, called 'the mean-expected loss measure with respect to hazard-free case', is shown to be more appropriate for systems in general. The concept of an 'efficient environment' is also proposed. All quantities used in the equations are precisely defined and their units specified. The equations reduce to numerical expressions, and can be subjected to experimental test. The equations clarify and quantify basic principles, enabling designers and operators of systems to reason correctly about systems in complex situations. Spreng's Triangle, relating energy, time and information follows from the sharing equation. The epirical Markowitz-Sharpe-Lintner relationship betwen return, capital resources and risk for financial systems follows from the basic risk equation.
Open Access
FLOWCHARTS FOR PH.D PROGRAM AT DEPARTMENT OF COMPUTER SCIENCE
(1986-01-01) Bradley, James
The rules for the Ph.D program are complex. As it is clearly impossible for anyone, whether experienced or not, to carry them around in his/her head, the flowcharts in this report should prove useful for handy reference. I would be grateful if errors in the flowcharts could be pointed out to me, so that they can be corrected in future editions.
Open Access
A FUNDAMENTAL SYSTEM HYPOTHESIS RELATING RESOURCES, RISK, COMPLEXITY AND EXPECTED OUTPUT IN AGENT-DIRECTED SYSTEMS
(1997-12-01) Bradley, James
A working hypothesis is presented and justified, called the Fundamental Systems Hypothesis. It relates expected net output value, complexity, risk and resources, and governs all agent-directed systems. The general veracity of this Hypothesis appears such that it could be considered a Fundamental Law of Systems. The risk measure is either conventional standard deviation risk or mean deviation risk. There are two risk parameters: positive and negative risk. There are two complexity parameters: monitoring or checking complexity, and resource scheduling & utilization complexity. Complexity is defined as a specification length after Gell-Mann. Both complexity parameters measure complexity in the system's environment-coping procedure that monitors an often close-to-random time function representing the unfolding environment. The Hypothesis is expressed as a mathematical relationship that reduces to numerical values for specific system circumstances. The established Markowitz-Sharpe-Lintner relationship between return, capital resources and risk for the subclass of financial systems is inherent in the Hypothesis. The Hypothesis can be subjected to experimental test.
Open Access
A FUNDAMENTAL SYSTEMS HYPOTHESIS RELATING RESOURCES, RISK, COMPLEXITY AND EXPECTED OUTPUT VALUE
(1998-12-01) Bradley, James
A working hypothesis is presented and justified, called the Fundamental Systems Hypothesis, governing all agent-directed systems. The Hypothesis is concisely expressed by five mathematical relationships, each covering a specific system aspect, any and all of which can be combined; they relate expected net output value, resources, environment, risk, complexity of a resource-sharing procedure, complexity of a precautionary procedure, and complexity of a monitoring procedure. Although it reduces, to numerical expressions for specific system circumstances, the main virtue of the Hypothesis is that it clarifies basic principles and thus helps designers and operators of systems to reason correctly about systems and avoid serious error. There are two risk parameters: positive and negative risk, and the risk measure can be either conventional standard deviation risk or mean deviation risk. There are three complexity parameters: resource-sharing complexity, precautionary complexity, and monitoring complexity. Both resource-sharing and precautionary complexity are defined as execution times; monitoring complexity is defined as negative entropy. The general veracity of this Hypothesis appears such that it could be considered a Fundamental Law of Systems. The Markowitz-Sharpe-Lintner relationship between return, capital resources and risk for the subclass of financial systems is inherent in the Hypothesis. The Hypothesis can be subjected to experimental test.
Open Access
A FUNDAMENTAL SYSTEMS HYPOTHESIS RELATING RESOURCES, RISK,COMPLEXITY AND EXPECTED OUTPUT VALUE
(1998-06-01) Bradley, James
A working hypothesis is presented and justified, called the Fundamental Systems Hypothesis. It relates expected net output value, complexity, risk and resources, and governs all human-agent-directed systems. The general veracity of this Hypothesis appears such that it could be considered a Fundamental Law of Systems. The risk measure can be either conventional standard deviation risk or mean deviation risk. There are two risk parameters: positive and negative risk. There are two complexity parameters: monitoring or checking complexity, and resource-sharing complexity. Monitoring complexity is defined as a specification length, and measures complexity in the system's environment-coping procedure that monitors a time function representing the unfolding environment. Resource-sharing complexity measures the execution time of a complex resource-sharing procedure. The Hypothesis is expressed as a mathematical relationship that reduces to numerical values for specific system circumstances. It also quantifies real economic losses, and gains, associated with system risk. The established Markowitz-Sharpe-Lintner relationship between return, capital resources and risk for the subclass of financial systems is inherent in the Hypothesis. The Hypothesis can be subjected to experimental test.
Open Access
A GENITIVE RELATIONAL TUPLE CALCULUS FOR AN OBJECT-ORIENTED RELATIONAL DATA MODEL
(1992-09-01) Bradley, James
A genitive relational tuple calculus, applicable to an object-oriented relational data base, has been developed. A key construct in the calculus is the genitive relation. This permits quite concise specification of complex objects and allows for quantification of relationships by means of any of the natural quantifiers. Tuple calculus expressions are composite-object oriented, as opposed to entire relation-orientation of conventional tuple calculus. The genitive relational tuple calculus can be used as a theoretical foundation for a new class of declarative relational languages, such as COOL (composite object-oriented language), a recently developed genitive relational object-oriented natural quantifier data base language for use with data bases as a subset of SQL. How the calculus is a basis for COOL is also briefly demonstrated.
Open Access
GENITIVE RELATIONS AND THE COMPOSITE OBJECT-ORIENTED LANGUAGE COOL FOR OBJECT SUPPORT IN $N sup 2$
(1992-08-01) Bradley, James
A distinction is made between two fundamentally different approaches to declarative languages for relational data bases. One approach is entire-relation oriented, embodied in tuple calculus and SQL. The other approach is composite-object oriented, the subject of this paper. Constructs for a composite-object oriented declarative language, called COOL, are proposed for use with relational data bases. To enable unambiguous specification and quantification of relationships, a construct called a genitive relation is introduced. The notion of composite-object concentration is also introduced. These constructs allow objects to be manipulated on the basis of quantified relationships between object instances, with universal, existential, and natural quantification. They also permit specification and concentration of composite objects of great complexity, and composite objects based on functional dependency relationships. COOL can also manipulate independent entity structures, both hierarchical and network, and generalization or IS-A type hierarchies. COOL is proposed as a subset of COOL, for use where a relational data base has a distinct object orientation.
Open Access
GRODEC STACK MACHINES FOR GENERATION OF EN: 1 GROWTH-DECAY FRACTAL TIME FUNCTIONS
(1994-10-01) Bradley, James
This paper analyses machines that exhibit time fractal growth-decay En:m function behaviour. It is largely concerned with the simpler types of En:m functions, namely the E5:1, E5:3, E7:1, E7:5 functions. An En:m function consists of replicating and endlessly subdivided series of alternating growth and decay segments. The machines involved are grodec stack machines, constructed from entities called grodecs. A grodec is a basic growth decay entity involving two stores of fluid and energy, connected via a one way switch. Grodec stack machines can be built from two kinds of grodecs, namely left sink grodecs and right source grodecs. This paper analyses four classes of grodec stack machines: left sink grodec stacks for equisegment En:1 functions and regular En:1 functions, and right source grodec stacks for negative equisegment En:1 functions and negative regular En:1 functions. Negative En:1 functions are fractal time functions that grow downwards. It appears that a machine for generating an En:m function with m > 1 is a combination of left sink and right source grodec stack machines, called a balanced grodec stack machine. Such a machine can also be called a chaos machine because of its sensitive dependence on initial conditions, and capacity for chaotic behaviour.
Open Access
GRODEC, THE GRODEC ACTION POTENTIAL, AND GRODEC-BASED NEURAL NETWORKS
(1995-12-01) Bradley, James
Grodecs are abstract growth decay entities that are related to oscillators. The switching behaviour of grodecs has been analysed in detail and it is shown that grodecs can be used as the basis of both an unconventional type of neural net called a grocec stack machine, as well as conventional neural nets. A single grodec has the most of the switching properties of a short section of biological membrane, and can give rise to action potentials when properly set. A pair of grodecs can generate a much sharper action potential than can a single grodec, and this mechanism is very like that of a neuron with dual Na and K ion switching, so that a neuron membrane can be regarded conceptually as a Na grodec coupled to a K grodec. Grodecs can be coupled in positive (excitatory) or negative (inhibitory) manner to form logic circuits. Examples of such circuits are given, and show that grodecs can be the basis of conventional neural nets and sequential machines in general. Grodecs can also be coupled in an unconventional manner to form grodec stack machines. In such machines the action potentials sum in periods of growth and decay, so that a central machine pressure parameter exhibits time function behaviour similar to that of a fractal growth-decay time function, such as an En:m function. Although the manner of the summation is much simpler than in grodec stack machines, action potential summation does occur in nature, and causes the large voltages generated by electric fish.