The Experts below are selected from a list of 71319 Experts worldwide ranked by ideXlab platform
Denise E De Souza - One of the best experts on this subject based on the ideXlab platform.
-
a critical realist translational social epidemiology protocol for concretising and contextualising a Theory of neighbourhood context stress depression and the developmental origins of health and disease dohad sydney australia
International Journal of Integrated Care, 2019Co-Authors: John Eastwood, Pankaj Garg, Ingrid Tyler, Lynn Kemp, Denise E De SouzaAbstract:Background: We will describe here a translational social epidemiology protocol for confirming a critical realist “Theory of Neighbourhood Context, Stress, Depression, and the Developmental Origins of Health and Disease (DOHaD)”. The approach will include the concretising and contextualising of the above Causal Theory into programme theories for child and adolescent interventions that aim to break intergenerational cycles of disadvantage and poor life outcomes. In undertaking this work we seek to advance realist translational methodology within the discipline of applied perinatal and paediatric social epidemiology. Theory and Methods: The research settings are in metropolitan Sydney. The design will be a longitudinal, multi-level, mixed method realist evaluation of applied programme interventions that seek to break the intergeneration cycle of social disadvantage and poor child health and developmental outcomes. The programme of research will consist of three components: 1) Operationalisation of the Theory and designing of programme initiatives for implementation; 2) Evaluation of the translated programme and implementation Theory using Theory of Change and critical realist evaluation; and 3) Theory Testing of realist hypotheses using both intensive and extensive critical realist research methods including realist structural modelling. Discussion: The proposed programme of research will assist in translating empirical explanatory Theory building to Theory driven interventions. The research will be situated in socially disadvantaged regions of Sydney where the local child and family inter-agencies will collaborate to design and implement new initiatives that address significant disparities in childhood development and adolescent outcomes attributed to neighbourhood circumstances, family stress and intergenerational cycles of disadvantage and poor mental health.
-
a protocol for concretizing and contextualizing a critical realist Theory of neighbourhood context stress depression and the developmental origins of health and disease dohd sydney australia
International Journal of Integrated Care, 2017Co-Authors: John Eastwood, Lynn Anne Kemp, Pankaj Garg, Ingrid Tyler, Denise E De SouzaAbstract:Introduction: This research protocol has been developed as part of an integrated care initiative for vulnerable families in Sydney, Australia. The aim is to develop “whole-of-government” interventions that break intergenerational cycles of disadvantage and poor life outcomes. A realist methodology will be described for the translation of empirically ‘data derived’ Causal middle-range theories of social mechanisms, into health and social programme theories, whose theoretical propositions can be operationalized and studied in concrete situations using collective Theory driven approaches. Theory/Methods: The research settings are in metropolitan Sydney, Australia. The design will be a longitudinal, multi-level, mixed method realist evaluation of applied programme interventions that seek to break the intergenerational cycle of social disadvantage and poor child health and developmental outcomes. The programme of research will consist of three components: 1) Operationalization of the Theory and designing of programme initiatives for implementation; 2) Evaluation of the translated programme and implementation Theory using Theory of Change and Realistic Evaluation; and 3) Theory Testing of realist hypotheses using both intensive and extensive critical realist research methods including realist structural modelling. Results: No applicable Discussion: The proposed programme of research will assist in translating empirical explanatory Theory building to Theory driven interventions. The research will be situated in socially disadvantaged regions of Sydney where the local child and family interagencies will collaborate to design and implement new initiatives that address significant disparities in early childhood development and adolescent outcomes attributed to neighbourhood circumstances, family stress and intergenerational cycles of disadvantage and poor mental health. Conclusions: Central to this protocol is the development of programme Theory. Much of the Theory driven and realist evaluation literature begins with existing interventions. The first task in those situations is to identify the underlying programme Theory. In preparing this programme of work we were faced with the translation of Causal Theory to programme and implementation Theory. We have proposed as a first step in this protocol the formal translation of the middle-range ‘Causal’ Theory into a middle-range ‘programme Theory’ followed by an intervention design process based on Theory of Change approaches. Lessons learned: In preparing the protocol we have identified extensive debate concern the nature of implementation Theory and programme Theory. There is also on-going critical analysis of the nature of context (c), mechanisms (M) and outcomes (o) and how these might be defined and measured. Limitations: The application of realist methodologies to population health interventions is relatively new and there is little extant literature on the translational process from Causal Theory to programme Theory. The study protocol is thus breaking new ground and it is anticipated that the approaches described will require modification. Suggestions for future research: The protocol development identified a need for further clarification of the nature of Causal mechanism and programme mechanisms among the integrated care and evaluation research communities.
Marek Sergot - One of the best experts on this subject based on the ideXlab platform.
-
making sense of sensory input
Artificial Intelligence, 2021Co-Authors: Richard Evans, Jose Hernandezorallo, Johannes Welbl, Pushmeet Kohli, Marek SergotAbstract:Abstract This paper attempts to answer a central question in unsupervised learning: what does it mean to “make sense” of a sensory sequence? In our formalization, making sense involves constructing a symbolic Causal Theory that both explains the sensory sequence and also satisfies a set of unity conditions. The unity conditions insist that the constituents of the Causal Theory – objects, properties, and laws – must be integrated into a coherent whole. On our account, making sense of sensory input is a type of program synthesis, but it is unsupervised program synthesis. Our second contribution is a computer implementation, the Apperception Engine , that was designed to satisfy the above requirements. Our system is able to produce interpretable human-readable Causal theories from very small amounts of data, because of the strong inductive bias provided by the unity conditions. A Causal Theory produced by our system is able to predict future sensor readings, as well as retrodict earlier readings, and impute (fill in the blanks of) missing sensory readings, in any combination. In fact, it is able to do all three tasks simultaneously. We tested the engine in a diverse variety of domains, including cellular automata, rhythms and simple nursery tunes, multi-modal binding problems, occlusion tasks, and sequence induction intelligence tests. In each domain, we test our engine's ability to predict future sensor values, retrodict earlier sensor values, and impute missing sensory data. The Apperception Engine performs well in all these domains, significantly out-performing neural net baselines. We note in particular that in the sequence induction intelligence tests, our system achieved human-level performance. This is notable because our system is not a bespoke system designed specifically to solve intelligence tests, but a general-purpose system that was designed to make sense of any sensory sequence.
-
evaluating the apperception engine
arXiv: Artificial Intelligence, 2020Co-Authors: Richard J Evans, Jose Hernandezorallo, Johannes Welbl, Pushmeet Kohli, Marek SergotAbstract:The Apperception Engine is an unsupervised learning system. Given a sequence of sensory inputs, it constructs a symbolic Causal Theory that both explains the sensory sequence and also satisfies a set of unity conditions. The unity conditions insist that the constituents of the Theory - objects, properties, and laws - must be integrated into a coherent whole. Once a Theory has been constructed, it can be applied to predict future sensor readings, retrodict earlier readings, or impute missing readings. In this paper, we evaluate the Apperception Engine in a diverse variety of domains, including cellular automata, rhythms and simple nursery tunes, multi-modal binding problems, occlusion tasks, and sequence induction intelligence tests. In each domain, we test our engine's ability to predict future sensor values, retrodict earlier sensor values, and impute missing sensory data. The engine performs well in all these domains, significantly outperforming neural net baselines and state of the art inductive logic programming systems. These results are significant because neural nets typically struggle to solve the binding problem (where information from different modalities must somehow be combined together into different aspects of one unified object) and fail to solve occlusion tasks (in which objects are sometimes visible and sometimes obscured from view). We note in particular that in the sequence induction intelligence tests, our system achieved human-level performance. This is notable because our system is not a bespoke system designed specifically to solve intelligence tests, but a general-purpose system that was designed to make sense of any sensory sequence.
John Eastwood - One of the best experts on this subject based on the ideXlab platform.
-
a critical realist translational social epidemiology protocol for concretising and contextualising a Theory of neighbourhood context stress depression and the developmental origins of health and disease dohad sydney australia
International Journal of Integrated Care, 2019Co-Authors: John Eastwood, Pankaj Garg, Ingrid Tyler, Lynn Kemp, Denise E De SouzaAbstract:Background: We will describe here a translational social epidemiology protocol for confirming a critical realist “Theory of Neighbourhood Context, Stress, Depression, and the Developmental Origins of Health and Disease (DOHaD)”. The approach will include the concretising and contextualising of the above Causal Theory into programme theories for child and adolescent interventions that aim to break intergenerational cycles of disadvantage and poor life outcomes. In undertaking this work we seek to advance realist translational methodology within the discipline of applied perinatal and paediatric social epidemiology. Theory and Methods: The research settings are in metropolitan Sydney. The design will be a longitudinal, multi-level, mixed method realist evaluation of applied programme interventions that seek to break the intergeneration cycle of social disadvantage and poor child health and developmental outcomes. The programme of research will consist of three components: 1) Operationalisation of the Theory and designing of programme initiatives for implementation; 2) Evaluation of the translated programme and implementation Theory using Theory of Change and critical realist evaluation; and 3) Theory Testing of realist hypotheses using both intensive and extensive critical realist research methods including realist structural modelling. Discussion: The proposed programme of research will assist in translating empirical explanatory Theory building to Theory driven interventions. The research will be situated in socially disadvantaged regions of Sydney where the local child and family inter-agencies will collaborate to design and implement new initiatives that address significant disparities in childhood development and adolescent outcomes attributed to neighbourhood circumstances, family stress and intergenerational cycles of disadvantage and poor mental health.
-
a protocol for concretizing and contextualizing a critical realist Theory of neighbourhood context stress depression and the developmental origins of health and disease dohd sydney australia
International Journal of Integrated Care, 2017Co-Authors: John Eastwood, Lynn Anne Kemp, Pankaj Garg, Ingrid Tyler, Denise E De SouzaAbstract:Introduction: This research protocol has been developed as part of an integrated care initiative for vulnerable families in Sydney, Australia. The aim is to develop “whole-of-government” interventions that break intergenerational cycles of disadvantage and poor life outcomes. A realist methodology will be described for the translation of empirically ‘data derived’ Causal middle-range theories of social mechanisms, into health and social programme theories, whose theoretical propositions can be operationalized and studied in concrete situations using collective Theory driven approaches. Theory/Methods: The research settings are in metropolitan Sydney, Australia. The design will be a longitudinal, multi-level, mixed method realist evaluation of applied programme interventions that seek to break the intergenerational cycle of social disadvantage and poor child health and developmental outcomes. The programme of research will consist of three components: 1) Operationalization of the Theory and designing of programme initiatives for implementation; 2) Evaluation of the translated programme and implementation Theory using Theory of Change and Realistic Evaluation; and 3) Theory Testing of realist hypotheses using both intensive and extensive critical realist research methods including realist structural modelling. Results: No applicable Discussion: The proposed programme of research will assist in translating empirical explanatory Theory building to Theory driven interventions. The research will be situated in socially disadvantaged regions of Sydney where the local child and family interagencies will collaborate to design and implement new initiatives that address significant disparities in early childhood development and adolescent outcomes attributed to neighbourhood circumstances, family stress and intergenerational cycles of disadvantage and poor mental health. Conclusions: Central to this protocol is the development of programme Theory. Much of the Theory driven and realist evaluation literature begins with existing interventions. The first task in those situations is to identify the underlying programme Theory. In preparing this programme of work we were faced with the translation of Causal Theory to programme and implementation Theory. We have proposed as a first step in this protocol the formal translation of the middle-range ‘Causal’ Theory into a middle-range ‘programme Theory’ followed by an intervention design process based on Theory of Change approaches. Lessons learned: In preparing the protocol we have identified extensive debate concern the nature of implementation Theory and programme Theory. There is also on-going critical analysis of the nature of context (c), mechanisms (M) and outcomes (o) and how these might be defined and measured. Limitations: The application of realist methodologies to population health interventions is relatively new and there is little extant literature on the translational process from Causal Theory to programme Theory. The study protocol is thus breaking new ground and it is anticipated that the approaches described will require modification. Suggestions for future research: The protocol development identified a need for further clarification of the nature of Causal mechanism and programme mechanisms among the integrated care and evaluation research communities.
Winfried Zimdahl - One of the best experts on this subject based on the ideXlab platform.
-
bulk viscous cosmology with Causal transport Theory
Journal of Cosmology and Astroparticle Physics, 2011Co-Authors: Oliver F Piattella, J C Fabris, Winfried ZimdahlAbstract:We consider cosmological scenarios originating from a single imperfect fluid with bulk viscosity and apply Eckart's and both the full and the truncated M?ller-Israel-Stewart's theories as descriptions of the non-equilibrium processes. Our principal objective is to investigate if the dynamical properties of Dark Matter and Dark Energy can be described by a single viscous fluid and how such description changes when a Causal Theory (M?ller-Israel-Stewart's, both in its full and truncated forms) is taken into account instead of Eckart's non-Causal one. To this purpose, we find numerical solutions for the gravitational potential and compare its behaviour with the corresponding ?CDM case. Eckart's and the full Causal Theory seem to be disfavoured, whereas the truncated Theory leads to results similar to those of the ?CDM model for a bulk viscous speed in the interval 10?11 cb2 10?8.
-
bulk viscous cosmology with Causal transport Theory
arXiv: Cosmology and Nongalactic Astrophysics, 2011Co-Authors: Oliver F Piattella, J C Fabris, Winfried ZimdahlAbstract:We consider cosmological scenarios originating from a single imperfect fluid with bulk viscosity and apply Eckart's and both the full and the truncated Muller-Israel-Stewart's theories as descriptions of the non-equilibrium processes. Our principal objective is to investigate if the dynamical properties of Dark Matter and Dark Energy can be described by a single viscous fluid and how such description changes when a Causal Theory (Muller-Israel-Stewart's, both in its full and truncated forms) is taken into account instead of Eckart's non-Causal Theory. To this purpose, we find numerical solutions for the gravitational potential and compare its behaviour with the corresponding LambdaCDM case. Eckart's and the full Causal Theory seem to be disfavoured, whereas the truncated Theory leads to results similar to those of the LambdaCDM model for a bulk viscous speed in the interval 10^{-11} << c_b^2 < 10^{-8}. Tentatively relating such value to a square propagation velocity of the order of T/m of perturbations in a non-relativistic gas of particles with mass m at the epoch of matter-radiation equality, this may be compatible with a mass range 0.1 GeV < m << 100 GeV.
Fangzhen Lin - One of the best experts on this subject based on the ideXlab platform.
-
compiling Causal theories to successor state axioms and strips like systems
arXiv: Artificial Intelligence, 2011Co-Authors: Fangzhen LinAbstract:We describe a system for specifying the effects of actions. Unlike those commonly used in AI planning, our system uses an action description language that allows one to specify the effects of actions using domain rules, which are state constraints that can entail new action effects from old ones. Declaratively, an action domain in our language corresponds to a nonmonotonic Causal Theory in the situation calculus. Procedurally, such an action domain is compiled into a set of logical theories, one for each action in the domain, from which fully instantiated successor state-like axioms and STRIPS-like systems are then generated. We expect the system to be a useful tool for knowledge engineers writing action specifications for classical AI planning systems, GOLOG systems, and other systems where formal specifications of actions are needed.
-
from Causal theories to successor state axioms and strips like systems
National Conference on Artificial Intelligence, 2000Co-Authors: Fangzhen LinAbstract:We describe a system for specifying the efiects of actions. Unlike those commonly used in AI planning, our system uses an action description language that allows one to specify the efiects of actions using domain rules, which are state constraints that can entail new action efiects from old ones. Declaratively, an action domain in our language corresponds to a nonmonotonic Causal Theory in the situation calculus. Procedurally, such an action domain is compiled into a set of propositional theories, one for each action in the domain, from which fully instantiated successor state-like axioms and STRIPS-like systems are then generated. We expect the system to be a useful tool for knowledge engineers writing action speciflcations for classical AI planning systems, GOLOG systems, and other systems where formal speciflcations of actions are needed.