On SPI-Lazy Evaluation of Influence Diagrams

2014 ◽  
pp. 97-112 ◽  
Author(s):  
Rafael Cabañas ◽  
Andrés Cano ◽  
Manuel Gómez-Olmedo ◽  
Anders L. Madsen
Keyword(s):  
Influence Diagrams ◽  
Lazy Evaluation

AN EXTENSION OF LAZY EVALUATION FOR INFLUENCE DIAGRAMS AVOIDING REDUNDANT VARIABLES IN THE POTENTIALS

2004 ◽  
Vol 12 (supp01) ◽  
pp. 1-17 ◽  
Author(s):  
MARTA VOMLELOVÁ ◽  
FINN V. JENSEN
Keyword(s):  
Evaluation Method ◽  
Structural Information ◽  
Partial Solution ◽  
Influence Diagrams ◽  
Lazy Evaluation ◽  
Standard Methods ◽  
Minimal Sets ◽  
Excessive Consumption ◽  
Elimination Of Variables ◽  
Large Domains

Standard methods for solving influence diagrams consist in stepwise elimination of variables, and along with elimination of a variable a set of new potentials over new domains is calculated. It is well known that these methods tend to produce unnecessarily large domains resulting in excessive consumption of time and memory. The lazy evaluation method represents only a partial solution to the problem. In this paper we extend any potential with two graphs over its domain representing the dependencies of variables. When a node A is eliminated, all necessary structural information for establishing the minimal sets of domains for potentials is contained in these graphs. We push lazy evaluation a step further to avoid performing unnecessary multiplications and subsequent division with equivalent potentials.

Approximate Lazy Evaluation of Influence Diagrams

2013 ◽  
pp. 321-331
Author(s):  
Rafael Cabañas ◽  
Andrés Cano ◽  
Manuel Gómez-Olmedo ◽  
Anders L. Madsen
Keyword(s):  
Influence Diagrams ◽  
Lazy Evaluation

Elicitation of expert knowledge to develop decision support tools for use in water demand management planning

2007 ◽  
Vol 7 (5-6) ◽  
pp. 53-60
Author(s):  
D. Inman ◽  
D. Simidchiev ◽  
P. Jeffrey
Keyword(s):  
Decision Support ◽  
Water Demand ◽  
Expert Knowledge ◽  
Demand Management ◽  
Decision Processes ◽  
Conservation Strategy ◽  
Influence Diagrams ◽  
Decision Support Tools ◽  
Water Demand Management ◽  
Support Tools

This paper examines the use of influence diagrams (IDs) in water demand management (WDM) strategy planning with the specific objective of exploring how IDs can be used in developing computer-based decision support tools (DSTs) to complement and support existing WDM decision processes. We report the results of an expert consultation carried out in collaboration with water industry specialists in Sofia, Bulgaria. The elicited information is presented as influence diagrams and the discussion looks at their usefulness in WDM strategy design and the specification of suitable modelling techniques. The paper concludes that IDs themselves are useful in developing model structures for use in evidence-based reasoning models such as Bayesian Networks, and this is in keeping with the objectives set out in the introduction of integrating DSTs into existing decision processes. The paper will be of interest to modellers, decision-makers and scientists involved in designing tools to support resource conservation strategy implementation.

Efficient compilation of lazy evaluation

1984 ◽  
Vol 19 (6) ◽  
pp. 58-69 ◽  
Author(s):  
Thomas Johnsson
Keyword(s):  
Lazy Evaluation

BullFrog: Online Schema Evolution via Lazy Evaluation

2021 ◽  
Author(s):  
Souvik Bhattacherjee ◽  
Gang Liao ◽  
Michael Hicks ◽  
Daniel J. Abadi
Keyword(s):  
Schema Evolution ◽  
Lazy Evaluation

scholarly journals Risk Assessment of Circuit Breakers Using Influence Diagrams with Interval Probabilities

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 737
Author(s):  
Jelena D. Velimirovic ◽  
Aleksandar Janjic
Keyword(s):  
Power System ◽  
Predictive Modelling ◽  
Optimal Time ◽  
Influence Diagrams ◽  
Circuit Breakers ◽  
Interval Probability ◽  
Complex Power ◽  
Interval Width ◽  
Credal Sets ◽  
The One

This paper deals with uncertainty, asymmetric information, and risk modelling in a complex power system. The uncertainty is managed by using probability and decision theory methods. More specifically, influence diagrams—as extended Bayesian network functions with interval probabilities represented through credal sets—were chosen for the predictive modelling scenario of replacing the most critical circuit breakers in optimal time. Namely, based on the available data on circuit breakers and other variables that affect the considered model of a complex power system, a group of experts was able to assess the situation using interval probabilities instead of crisp probabilities. Furthermore, the paper examines how the confidence interval width affects decision-making in this context and eliminates the information asymmetry of different experts. Based on the obtained results for each considered interval width separately on the action to be taken over the considered model in order to minimize the risk of the power system failure, it can be concluded that the proposed approach clearly indicates the advantages of using interval probability when making decisions in systems such as the one considered in this paper.

An operational semantics for parallel lazy evaluation

2000 ◽  
Vol 35 (9) ◽  
pp. 162-173 ◽  
Author(s):  
Clem Baker-Finch ◽  
David J. King ◽  
Phil Trinder
Keyword(s):  
Operational Semantics ◽  
Lazy Evaluation

scholarly journals A Note on Equivalence Classes of Directed Acyclic Independence Graphs

1993 ◽  
Vol 7 (3) ◽  
pp. 409-412 ◽  
Author(s):  
David Madigan
Keyword(s):  
Model Selection ◽  
Expert Systems ◽  
Equivalence Classes ◽  
Influence Diagrams ◽  
Single Class ◽  
Selection Procedures ◽  
Probabilistic Expert Systems ◽  
Recent Developments ◽  
Independence Graphs ◽  
Markov Properties

Directed acyclic independence graphs (DAIGs) play an important role in recent developments in probabilistic expert systems and influence diagrams (Chyu [1]). The purpose of this note is to show that DAIGs can usefully be grouped into equivalence classes where the members of a single class share identical Markov properties. These equivalence classes can be identified via a simple graphical criterion. This result is particularly relevant to model selection procedures for DAIGs (see, e.g., Cooper and Herskovits [2] and Madigan and Raftery [4]) because it reduces the problem of searching among possible orientations of a given graph to that of searching among the equivalence classes.

AN OPERATIONAL SEMANTICS FOR THE PARALLEL LANGUAGE EDEN

2002 ◽  
Vol 12 (02) ◽  
pp. 211-228 ◽  
Author(s):  
MERCEDES HIDALGO-HERRERO ◽  
YOLANDA ORTEGA-MALLÉN
Keyword(s):  
Operational Semantics ◽  
Transition System ◽  
Lazy Evaluation ◽  
Parallel Language ◽  
Parallel Processes ◽  
System A ◽  
Independent Evaluation ◽  
Level Transition ◽  
Concurrent Algorithms ◽  
Main Thread

The functional parallel language Eden — suitable for the description of parallel and concurrent algorithms in a distributed setting — is an extension of Haskell with a set of coordination features. In this paper we present a formal operational semantics for the kernel of Eden, or more precisely, for a λ-calculus widened with explicit parallelism and potentially infinite communication channels. Eden overrides the lazy nature of Haskell on behalf of parallelism. This interplay between laziness and eagerness is accurately described by the semantics proposed here, which is based on Launchbury's natural semantics for lazy evaluation, and is expressed through a two-level transition system: a lower level for the local and independent evaluation of each process, and an upper one for the coordination between all the parallel processes in the system. As processes are created either under demand or in a speculative way, different scheduling strategies are possible — ranging from a minimal one that only allows the main thread to evolve, to a maximal one that evolves in parallel every active binding.

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