893 resultados para principle of survivorship
Resumo:
It is a neural network truth universally acknowledged, that the signal transmitted to a target node must be equal to the product of the path signal times a weight. Analysis of catastrophic forgetting by distributed codes leads to the unexpected conclusion that this universal synaptic transmission rule may not be optimal in certain neural networks. The distributed outstar, a network designed to support stable codes with fast or slow learning, generalizes the outstar network for spatial pattern learning. In the outstar, signals from a source node cause weights to learn and recall arbitrary patterns across a target field of nodes. The distributed outstar replaces the outstar source node with a source field, of arbitrarily many nodes, where the activity pattern may be arbitrarily distributed or compressed. Learning proceeds according to a principle of atrophy due to disuse whereby a path weight decreases in joint proportion to the transmittcd path signal and the degree of disuse of the target node. During learning, the total signal to a target node converges toward that node's activity level. Weight changes at a node are apportioned according to the distributed pattern of converging signals three types of synaptic transmission, a product rule, a capacity rule, and a threshold rule, are examined for this system. The three rules are computationally equivalent when source field activity is maximally compressed, or winner-take-all when source field activity is distributed, catastrophic forgetting may occur. Only the threshold rule solves this problem. Analysis of spatial pattern learning by distributed codes thereby leads to the conjecture that the optimal unit of long-term memory in such a system is a subtractive threshold, rather than a multiplicative weight.
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This article describes two neural network modules that form part of an emerging theory of how adaptive control of goal-directed sensory-motor skills is achieved by humans and other animals. The Vector-Integration-To-Endpoint (VITE) model suggests how synchronous multi-joint trajectories are generated and performed at variable speeds. The Factorization-of-LEngth-and-TEnsion (FLETE) model suggests how outflow movement commands from a VITE model may be performed at variable force levels without a loss of positional accuracy. The invariance of positional control under speed and force rescaling sheds new light upon a familiar strategy of motor skill development: Skill learning begins with performance at low speed and low limb compliance and proceeds to higher speeds and compliances. The VITE model helps to explain many neural and behavioral data about trajectory formation, including data about neural coding within the posterior parietal cortex, motor cortex, and globus pallidus, and behavioral properties such as Woodworth's Law, Fitts Law, peak acceleration as a function of movement amplitude and duration, isotonic arm movement properties before and after arm-deafferentation, central error correction properties of isometric contractions, motor priming without overt action, velocity amplification during target switching, velocity profile invariance across different movement distances, changes in velocity profile asymmetry across different movement durations, staggered onset times for controlling linear trajectories with synchronous offset times, changes in the ratio of maximum to average velocity during discrete versus serial movements, and shared properties of arm and speech articulator movements. The FLETE model provides new insights into how spina-muscular circuits process variable forces without a loss of positional control. These results explicate the size principle of motor neuron recruitment, descending co-contractive compliance signals, Renshaw cells, Ia interneurons, fast automatic reactive control by ascending feedback from muscle spindles, slow adaptive predictive control via cerebellar learning using muscle spindle error signals to train adaptive movement gains, fractured somatotopy in the opponent organization of cerebellar learning, adaptive compensation for variable moment-arms, and force feedback from Golgi tendon organs. More generally, the models provide a computational rationale for the use of nonspecific control signals in volitional control, or "acts of will", and of efference copies and opponent processing in both reactive and adaptive motor control tasks.
Resumo:
The recognition and protection of constitutional rights is a fundamental precept. In Ireland, the right to marry is provided for in the equality provisions of Article 40 of the Irish Constitution (1937). However, lesbians and gay men are denied the right to marry in Ireland. The ‘last word’ on this issue came into being in the High Court in 2006, when Katherine Zappone and Ann Louise Gilligan sought, but failed, to have their Canadian marriage recognised in Ireland. My thesis centres on this constitutional court ruling. So as to contextualise the pursuit of marriage equality in Ireland, I provide details of the Irish trajectory vis-à-vis relationship and family recognition for same-sex couples. In Chapter One, I discuss the methodological orientation of my research, which derives from a critical perspective. Chapter Two denotes my theorisation of the principle of equality and the concept of difference. In Chapter Three, I discuss the history of the institution of marriage in the West with its legislative underpinning. Marriage also has a constitutional underpinning in Ireland, which derives from Article 41 of our Constitution. In Chapter Four, I discuss ways in which marriage and family were conceptualised in Ireland, by looking at historical controversies surrounding the legalisation of contraception and divorce. Chapter Five denotes a Critical Discourse Analysis of the High Court ruling in Zappone and Gilligan. In Chapter Six, I critique text from three genres of discourse, i.e. ‘Letters to the Editor’ regarding same-sex marriage in Ireland, communication from legislators vis-à-vis the 2004 legislative impediment to same-sex marriage in Ireland, and parliamentary debates surrounding the 2010 enactment of civil partnership legislation in Ireland. I conclude my research by reflecting on my methodological and theoretical considerations with a view to answering my research questions. Author’s Update: Following the outcome of the 2015 constitutional referendum vis-à-vis Article 41, marriage equality has been realised in Ireland.
Resumo:
This dissertation involves a general overview of the meditative practice of zazen and analytic philosophy of mind while suggesting a potential bridge between them in the form of an analysis of the practicality of realising impermanence. By the end of my argument I hope to have offered up some compelling evidence in favour of the idea that analytic philosophy would benefit greatly from adopting principles which are best learned and expressed through the practice of, and scholarship around, Zen Buddhism and in particular the treatment of the concept of impermanence. I demonstrate the Western philosophical tendency to make dichotomous assumptions about the nature of mind, even when explicitly denying a dualist framework. I do so by examining the historical and philosophical precedent for dualistic thinking in the work of figures such as Plato and Descartes. I expand on this idea by examining the psychology of categorisation - i.e. creating mental categories and boundaries - and demonstrating how such categorisations feeds back into behaviour in practical ways, both positive and negative. The Zen Buddhist principle of impermanence states that all phenomena are impermanent and therefore lack essential nature; this includes intellectual concepts such as the metaphysical framework of the analytic approach to mind. Impermanence is a principle which is realised through the embodied practice of zazen. By demonstrating its application to analytic philosophy of mind I show that zazen (and mindfulness practice in general) provides an ongoing opportunity for clearing up entrenched world views, metaphysical assumptions and dogmatic thinking. This in turn may promote a more holistic and ultimately more rewarding comprehension of the role of first-person experience in understanding the world. My argument is not limited to analytic philosophy of mind but reflects broad aspects of thinking in general, and I explain its application to issues of social importance, in particular education systems.
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Belief revision is a well-research topic within AI. We argue that the new model of distributed belief revision as discussed here is suitable for general modelling of judicial decision making, along with extant approach as known from jury research. The new approach to belief revision is of general interest, whenever attitudes to information are to be simulated within a multi-agent environment with agents holding local beliefs yet by interaction with, and influencing, other agents who are deliberating collectively. In the approach proposed, it's the entire group of agents, not an external supervisor, who integrate the different opinions. This is achieved through an election mechanism, The principle of "priority to the incoming information" as known from AI models of belief revision are problematic, when applied to factfinding by a jury. The present approach incorporates a computable model for local belief revision, such that a principle of recoverability is adopted. By this principle, any previously held belief must belong to the current cognitive state if consistent with it. For the purposes of jury simulation such a model calls for refinement. Yet we claim, it constitutes a valid basis for an open system where other AI functionalities (or outer stiumuli) could attempt to handle other aspects of the deliberation which are more specifi to legal narrative, to argumentation in court, and then to the debate among the jurors.
Resumo:
Belief revision is a well-researched topic within Artificial Intelligence (AI). We argue that the new model of belief revision as discussed here is suitable for general modelling of judicial decision making, along with the extant approach as known from jury research. The new approach to belief revision is of general interest, whenever attitudes to information are to be simulated within a multi-agent environment with agents holding local beliefs yet by interacting with, and influencing, other agents who are deliberating collectively. The principle of 'priority to the incoming information', as known from AI models of belief revision, is problematic when applied to factfinding by a jury. The present approach incorporates a computable model for local belief revision, such that a principle of recoverability is adopted. By this principle, any previously held belief must belong to the current cognitive state if consistent with it. For the purposes of jury simulation such a model calls for refinement. Yet, we claim, it constitutes a valid basis for an open system where other AI functionalities (or outer stimuli) could attempt to handle other aspects of the deliberation which are more specific to legal narratives, to argumentation in court, and then to the debate among the jurors.
Resumo:
Explains the equitable doctrine of subrogation as it applies to tenants, assignees and landlords. Outlines the basic principle of subrogation and examines how the principle affects the legal position of the original tenant, the tenant's assignee, the tenant's surety and the original landlord.
Resumo:
The firm adhesion of flavouring particles onto crisp surfaces during coating processes is a major concern in the snack production industry. Detachment of flavouring powders from products during handling and production stages can lead to substantial financial losses for the industry, in terms of variable flavour performance and extended cleaning down time of fugitive particle build-up on process equipment. Understanding the adhesion strength of applied bulk particulates used for flavouring formulations will help analysts to evaluate the efficiency of coating processes and potentially enable them to assess the adhesion strength of newly formulated flavouring powder prior to commitment to full scale plant trials. A rapid prototype of a novel adhesion tester has been designed and constructed. The apparatus operates according to the principle of impact force acting on particles attached to the surface of the food substrate. The main component is a circular plate to which four sample holders are attached and which is subjected to vertical travel down a guide shaft. Several flavouring powders have been tested extensively. By plotting the detachment versus impact force, the difference obtained between adhesion strength of different flavouring powders (which is a strong function of particle size) has been discussed.
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The botanic origin and the protein content of 15 honeys from small bee farms exploitations of Galicia, for family consume, were studied; the aim is to check if the protein wealth and the pollen wealth are dependent parameters. Seven honeys resulted to be Rhamnus frangula unifloral (pollen patterns with low diversity), two Castanea sativa Miller unifloral, other one heather unifloral, and five was multifloral honeys of various pollen patterns (four Castanea predominant and one Rhamnus frangula predominant). Their pollen wealth was low; eight honeys classified in the Maurizio Class I, 3 in Class II, 2 in Class III, and one in Maurizio Class IV. There has been a wide variability in its protein content (0.09- 4.83 mg prot./g honey). The relative amount of pollen from different taxa has a direct or inverse proportionality to wealth protein.
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Jurgen Habermas takes the realization of rights through the democratic self-organization of legal communities to be the normative core of emancipatory politics. In this article I explore the implications of this claim in relation to the requirements of justice. I argue that Habermas's discourse theory of democratic legitimacy presupposes a substantive principle of justice that demands the equalization of effective communicative freedom for all structurally constituted social groups in any constitutional state. This involves the elimination of a range of structural injustices rooted in the complex interrelationships between political, economic and cultural orders. In the final section I sketch briefly the implications of this analysis in the context of ongoing globalization processes. It is suggested that the most effective way to establish a just system of global governance is to equalize effective communicative freedom among nation-states.
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We investigate entanglement properties of a recently introduced class of macroscopic quantum superpositions in two-mode mixed states. One of the tools we use in order to infer the entanglement in this non-Gaussian class of states is the power to entangle a qubit system. Our study reveals features which are hidden in a standard approach to entanglement investigation based on the uncertainty principle of the quadrature variables. We briefly describe the experimental setup corresponding to our theoretical scenario and a suitable modification of the protocol which makes our proposal realizable within the current experimental capabilities.
Resumo:
The density functional theory (DFT) based hard-soft acid-base (HSAB) reactivity indices, including the electrophilicity index, have been successfully applied to many areas of molecular chemistry. In this work we test the applicability of such an approach to fundamental surface chemistry. We have considered, as prototypical surface reactions, both the hydrogenation of atomic nitrogen and the dissociative adsorption of the NH molecular radical. By use of a DFT methodology, the minimum energy reaction pathways, and corresponding reaction barriers, of the above reactions over Zr(001), Nb(110), Mo(110), Tc(001), Ru(001), Rh(111), and Pd(111) have been determined. By consideration of the chemical potential and chemical hardness of the surface metal atoms, and the principle of electronegativity equalization, it is found that the charge transferred to the NH radical during the process of dissociative adsorption correlates very well with that determined by Mulliken population analysis. Furthermore, it is found that the stability of the NH/surface transition state complex relates directly to this charge transfer and that the trend in transition state stability predicted by a HSAB; treatment correlates very strongly with that determined by DFT calculations. With regards to N hydrogenation, we find that during the course of the reaction, H loses cohesion to the surface, as it must migrate from a 3-fold hollow site to either a bridge or top site, to react with N. Partial density of states (PDOS) and Mulliken population analysis reveal that this loss of bonding is accompanied by charge transfer from H to the surface metal atoms. Moreover, by simple modeling, we show that the reaction barriers are directly proportional to this mandatory charge transfer. Indeed, it is found that the reaction barriers correlate very well with the electrophilicity index of the metal atoms.
Resumo:
Purpose: One mechanism of tumor resistance to cytotoxic therapy is repair of damaged DNA. Poly(ADP-ribose) polymerase (PARP)-1 is a nuclear enzyme involved in base excision repair, one of the five major repair pathways. PARP inhibitors are emerging as a new class of agents that can potentiate chemotherapy and radiotherapy. The article reports safety, efficacy, pharmacokinetic, and pharmacodynamic results of the first-in-class trial of a PARP inhibitor, AG014699, combined with temozolomide in adults with advanced malignancy.
Experimental Design: Initially, patients with solid tumors received escalating doses of AG014699 with 100 mg/m2/d temozolomide × 5 every 28 days to establish the PARP inhibitory dose (PID). Subsequently, AG014699 dose was fixed at PID and temozolomide escalated to maximum tolerated dose or 200 mg/m2 in metastatic melanoma patients whose tumors were biopsied. AG014699 and temozolomide pharmacokinetics, PARP activity, DNA strand single-strand breaks, response, and toxicity were evaluated.
Results: Thirty-three patients were enrolled. PARP inhibition was seen at all doses; PID was 12 mg/m2 based on 74% to 97% inhibition of peripheral blood lymphocyte PARP activity. Recommended doses were 12 mg/m2 AG014699 and 200 mg/m2 temozolomide. Mean tumor PARP inhibition at 5 h was 92% (range, 46-97%). No toxicity attributable to AG014699 alone was observed. AG014699 showed linear pharmacokinetics with no interaction with temozolomide. All patients treated at PID showed increases in DNA single-strand breaks and encouraging evidence of activity was seen.
Conclusions: The combination of AG014699 and temozolomide is well tolerated, pharmacodynamic assessments showing proof of principle of the mode of action of this new class of agents.
Heat capacities of ionic liquids as a function of temperature at 0.1 MPa. measurement and prediction
Resumo:
Heat capacities of nine ionic liquids were measured from (293 to 358) K by using a heat flux differential scanning calorimeter. The impact of impurities (water and chloride content) in the ionic liquid was analyzed to estimate the overall uncertainty. The Joback method for predicting ideal gas heat capacities has been extended to ionic liquids by the generation of contribution parameters for three new groups. The principle of corresponding states has been employed to enable the subsequent calculation of liquid heat capacities for ionic liquids, based on critical properties predicted using the modified Lydersen-Joback-Reid method, as a function of the temperature from (256 to 470) K. A relative absolute deviation of 2.9% was observed when testing the model against 961 data points from 53 different ionic liquids reported previously and measured within this study.
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This article evaluates Bauer's theory of the nation and the debateon national-cultural autonomy in late imperial Austria. It finds important similarities with contemporary liberal debates on multiculturalism and the rights of ethnic and national minorities. It argues that the debate on national-cultural autonomy went in some respects beyond the contemporary debate on multiculturalism. National-cultural autonomy rejects the idea of the nation-state and proposes instead a multi-nation-state that recognises differential rights for ethnic and national minorities. It seeks to break the limitations of liberal democracy and the territorial principle of the nation-state by organising national communities as deterritorialised national corporations, and multination-states as territorialised non-national identities.