To see the other types of publications on this topic, follow the link: Associative strength model.
Journal articles on the topic 'Associative strength model'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Associative strength model.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Rizzuto, Daniel S., and Michael J. Kahana. "An Autoassociative Neural Network Model of Paired-Associate Learning." Neural Computation 13, no. 9 (September 1, 2001): 2075–92. http://dx.doi.org/10.1162/089976601750399317.
Full textAbstract:
Hebbian heteroassociative learning is inherently asymmetric. Storing a forward association, from item A to item B, enables recall of B (given A), but does not permit recall of A (given B). Recurrent networks can solve this problem by associating A to B and B back to A. In these recurrent networks, the forward and backward associations can be differentially weighted to account for asymmetries in recall performance. In the special case of equal strength forward and backward weights, these recurrent networks can be modeled as a single autoassociative network where A and B are two parts of a single, stored pattern. We analyze a general, recurrent neural network model of associative memory and examine its ability to fit a rich set of experimental data on human associative learning. The model fits the data significantly better when the forward and backward storage strengths are highly correlated than when they are less correlated. This network-based analysis of associative learning supports the view that associations between symbolic elements are better conceptualized as a blending of two ideas into a single unit than as separately modifiable forward and backward associations linking representations in memory.
2
Rasmussen, Anders, Riccardo Zucca, Fredrik Johansson, Dan-Anders Jirenhed, and Germund Hesslow. "Purkinje cell activity during classical conditioning with different conditional stimuli explains central tenet of Rescorla–Wagner model." Proceedings of the National Academy of Sciences 112, no. 45 (October 26, 2015): 14060–65. http://dx.doi.org/10.1073/pnas.1516986112.
Full textAbstract:
A central tenet of Rescorla and Wagner’s model of associative learning is that the reinforcement value of a paired trial diminishes as the associative strength between the presented stimuli increases. Despite its fundamental importance to behavioral sciences, the neural mechanisms underlying the model have not been fully explored. Here, we present findings that, taken together, can explain why a stronger association leads to a reduced reinforcement value, within the context of eyeblink conditioning. Specifically, we show that learned pause responses in Purkinje cells, which trigger adaptively timed conditioned eyeblinks, suppress the unconditional stimulus (US) signal in a graded manner. Furthermore, by examining how Purkinje cells respond to two distinct conditional stimuli and to a compound stimulus, we provide evidence that could potentially help explain the somewhat counterintuitive overexpectation phenomenon, which was derived from the Rescorla–Wagner model.
3
Destrebecqz, Arnaud, Michaël Vande Velde, Estibaliz San Anton, Axel Cleeremans, and Julie Bertels. "Saving the Perruchet effect: A role for the strength of the association in associative learning." Quarterly Journal of Experimental Psychology 72, no. 6 (August 9, 2018): 1379–86. http://dx.doi.org/10.1177/1747021818791079.
Full textAbstract:
In a partial reinforcement schedule where a cue repeatedly predicts the occurrence of a target in consecutive trials, reaction times to the target tend to decrease in a monotonic fashion, while participants’ expectancies for the target decrease at the same time. This dissociation between reaction times and expectancies—the so-called Perruchet effect—challenges the propositional view of learning, which posits that human conditioned responses result from conscious inferences about the relationships between events. However, whether the reaction time pattern reflects the strength of a putative cue-target link, or only non-associative processes, such as motor priming, remains unclear. To address this issue, we implemented the Perruchet procedure in a two-choice reaction time task and compared reaction time patterns in an Experimental condition, in which a tone systematically preceded a visual target, and in a Control condition, in which the onset of the two stimuli were uncoupled. Participants’ expectancies regarding the target were recorded separately in an initial block. Reaction times decreased with the succession of identical trials in both conditions, reflecting the impact of motor priming. Importantly, reaction time slopes were steeper in the Experimental than in the Control condition, indicating an additional influence of the associative strength between the two stimuli. Interestingly, slopes were less steep for participants who showed the gambler’s fallacy in the initial block. In sum, our results suggest the mutual influences of motor priming, associative strength, and expectancies on performance. They are in line with a dual-process model of learning involving both a propositional reasoning process and an automatic link-formation mechanism.
4
Maki, William S. "A database of associative strengths from the strength-sampling model: A theory-based supplement to the Nelson, McEvoy, and Schreiber word association norms." Behavior Research Methods 40, no. 1 (February 2008): 232–35. http://dx.doi.org/10.3758/brm.40.1.232.
Full text
5
Maximov, P. V., and V. V. Maximov. "Visual Associative Memory Simulates the McCollough Effect." Perception 26, no. 1_suppl (August 1997): 260. http://dx.doi.org/10.1068/v970140.
Full textAbstract:
The McCollough effect (ME) refers to the phenomenon that, after a few minutes' exposure to gratings differing in both orientation and colour, subjects perceive similarly oriented achromatic gratings as if they were tinted with complementary hues. The traditional explanation of the ME as an adaptation of detectors selective for colour and orientation suffers from a number of inconsistencies: (i) the ME lasts much longer than ordinary adaptation, the decay of the effect being completely arrested during a night's sleep, or by occluding the eye for a long time; (ii) the strength of the ME is practically independent of the intensity of the adapting light; and (iii) a set of related pattern-contingent aftereffects discovered later would require, for explanation on similar lines, new detectors specific to other patterns. These properties can be explained, however, in the framework of associative memory and novelty filters. A computational model has been developed which consists of (i) an input layer of two (left and right eyes) square matrices with two analog receptors (red and green) in each pixel; (ii) an isomorphic associative neural layer, each neuron being synaptically connected with all receptors of both eyes; and (iii) an output layer (novelty filter). Modification of synaptic efficacies conforms to the Hebb learning rule. After a few presentations of coloured gratings the model displays the ME, which is slowly destroyed by subsequent presentations of random pictures. With a sufficiently large receptor matrix the effect lasts a thousand times longer than the period of learning. Continuous darkness does not change the strength of the effect. Like the real ME, the model does not display interocular transfer, but with other adapting patterns it shows the disparity-contingent colour aftereffect (thus confirming the connections with both eyes). The model can account for different pattern-contingent colour aftereffects without assuming any predetermined specific detectors. Such detectors are constructed in the course of adaptation to specific stimuli (gratings).
6
Zaksaite, Tara, and Peter M. Jones. "The redundancy effect is related to a lack of conditioned inhibition: Evidence from a task in which excitation and inhibition are symmetrical." Quarterly Journal of Experimental Psychology 73, no. 2 (October 8, 2019): 260–78. http://dx.doi.org/10.1177/1747021819878430.
Full textAbstract:
Rescorla and Wagner’s model of learning describes excitation and inhibition as symmetrical opposites. However, tasks used in human causal learning experiments, such as the allergist task, generally involve learning about cues leading to the presence or absence of the outcome, which may not reflect this assumption. This is important when considering learning effects which provide a challenge to this model, such as the redundancy effect. The redundancy effect describes higher causal ratings for the blocked cue X than for the uncorrelated cue Y in the design A+/AX+/BY+/CY–, the opposite pattern to that predicted by the Rescorla–Wagner model, which predicts higher associative strength for Y than for X. Crucially, this prediction depends on cue C gaining some inhibitory associative strength. In this article, we used a task in which cues could have independent inhibitory effects on the outcome, to investigate whether a lack of inhibition was related to the redundancy effect. In Experiment 1, inhibition for C was not detected in the allergist task, supporting this possibility. Three further experiments using the alternative task showed that a lack of inhibition was related to the redundancy effect: the redundancy effect was smaller when C was rated as inhibitory. Individual variation in the strength of inhibition for C also determined the size of the redundancy effect. Given that weak inhibition was detected in the alternative scenario but not in the allergist task, we recommend carefully choosing the type of task used to investigate associative learning phenomena, as it may influence results.
7
Elliott, Terry. "Variations on the Theme of Synaptic Filtering: A Comparison of Integrate-and-Express Models of Synaptic Plasticity for Memory Lifetimes." Neural Computation 28, no. 11 (November 2016): 2393–460. http://dx.doi.org/10.1162/neco_a_00889.
Full textAbstract:
Integrate-and-express models of synaptic plasticity propose that synapses integrate plasticity induction signals before expressing synaptic plasticity. By discerning trends in their induction signals, synapses can control destabilizing fluctuations in synaptic strength. In a feedforward perceptron framework with binary-strength synapses for associative memory storage, we have previously shown that such a filter-based model outperforms other, nonintegrative, “cascade”-type models of memory storage in most regions of biologically relevant parameter space. Here, we consider some natural extensions of our earlier filter model, including one specifically tailored to binary-strength synapses and one that demands a fixed, consecutive number of same-type induction signals rather than merely an excess before expressing synaptic plasticity. With these extensions, we show that filter-based models outperform nonintegrative models in all regions of biologically relevant parameter space except for a small sliver in which all models encode memories only weakly. In this sliver, which model is superior depends on the metric used to gauge memory lifetimes (whether a signal-to-noise ratio or a mean first passage time). After comparing and contrasting these various filter models, we discuss the multiple mechanisms and timescales that underlie both synaptic plasticity and memory phenomena and suggest that multiple, different filtering mechanisms may operate at single synapses.
8
Wiedemann, Amelie U., Benjamin Gardner, Nina Knoll, and Silke Burkert. "Intrinsic Rewards, Fruit and Vegetable Consumption, and Habit Strength: A Three-Wave Study Testing the Associative-Cybernetic Model." Applied Psychology: Health and Well-Being 6, no. 1 (November 14, 2013): 119–34. http://dx.doi.org/10.1111/aphw.12020.
Full text
9
Knoblauch, Andreas, Günther Palm, and Friedrich T. Sommer. "Memory Capacities for Synaptic and Structural Plasticity." Neural Computation 22, no. 2 (February 2010): 289–341. http://dx.doi.org/10.1162/neco.2009.08-07-588.
Full textAbstract:
Neural associative networks with plastic synapses have been proposed as computational models of brain functions and also for applications such as pattern recognition and information retrieval. To guide biological models and optimize technical applications, several definitions of memory capacity have been used to measure the efficiency of associative memory. Here we explain why the currently used performance measures bias the comparison between models and cannot serve as a theoretical benchmark. We introduce fair measures for information-theoretic capacity in associative memory that also provide a theoretical benchmark. In neural networks, two types of manipulating synapses can be discerned: synaptic plasticity, the change in strength of existing synapses, and structural plasticity, the creation and pruning of synapses. One of the new types of memory capacity we introduce permits quantifying how structural plasticity can increase the network efficiency by compressing the network structure, for example, by pruning unused synapses. Specifically, we analyze operating regimes in the Willshaw model in which structural plasticity can compress the network structure and push performance to the theoretical benchmark. The amount C of information stored in each synapse can scale with the logarithm of the network size rather than being constant, as in classical Willshaw and Hopfield nets (⩽ ln 2 ≈ 0.7). Further, the review contains novel technical material: a capacity analysis of the Willshaw model that rigorously controls for the level of retrieval quality, an analysis for memories with a nonconstant number of active units (where C ⩽ 1/eln 2 ≈ 0.53), and the analysis of the computational complexity of associative memories with and without network compression.
10
Abedini, Armin, Cliff Butcher, and Michael Worswick. "Application of an Evolving Non-Associative Anisotropic-Asymmetric Plasticity Model for a Rare-Earth Magnesium Alloy." Metals 8, no. 12 (December 2, 2018): 1013. http://dx.doi.org/10.3390/met8121013.
Full textAbstract:
Magnesium sheet metal alloys have a hexagonal close packed (hcp) crystal structure that leads to severe evolving anisotropy and tension-compression asymmetry as a result of the activation of different deformation mechanisms (slip and twinning) that are extremely challenging to model numerically. The low density of magnesium alloys and their high specific strength relative to steel and aluminum alloys make them promising candidates for automotive light-weighting but standard phenomenological plasticity models cannot adequately capture the complex plastic response of these materials. In this study, the constitutive plastic behavior of a rare-earth magnesium alloy sheet, ZEK100 (O-temper), was considered at room temperature, under quasi-static conditions. The CPB06 yield criterion for hcp materials was employed along with a non-associative flow rule in which the yield function and plastic potential were calibrated for a range of plastic deformation levels to account for evolving anisotropy under proportional loading. The non-associative flow rule has not previously been applied to magnesium alloys which require the use of flexible constitutive models to capture the severe anisotropy and its evolution with plastic deformation. The non-associative flow rule can provide the required flexibility by decoupling the yield function and plastic potential. For the associative flow rule, such flexibility can only be achieved by multiple linear transformations of the stress tensor resulting in expensive models for calibration and simulations. The constitutive model was implemented as a user material subroutine (UMAT) within the commercial finite element software, LS-DYNA, for general 3-D stress states along with an interpolation technique to consider the evolution of anisotropy based upon the plastic work. To evaluate the accuracy of the implemented model, predictions of a single-element model were compared with the experimental results in terms of flow stresses and plastic flow directions under various proportional loading conditions and along different test directions. Finally, to assess the predictive capabilities of the model, full-scale simulations of coupon-level formability experiments were performed and compared with experimental results in terms of far-field load-displacement and local strain paths. Using these experiments, the constitutive model was evaluated across the full range of representative stress states for sheet metal forming operations. It was shown that the predictions of the model were in very good agreement with experimental data.
11
Blanco, Fernando, and Joaquín Moris. "Bayesian methods for addressing long-standing problems in associative learning: The case of PREE." Quarterly Journal of Experimental Psychology 71, no. 9 (January 1, 2018): 1844–59. http://dx.doi.org/10.1080/17470218.2017.1358292.
Full textAbstract:
Most associative models typically assume that learning can be understood as a gradual change in associative strength that captures the situation into one single parameter, or representational state. We will call this view single-state learning. However, there is ample evidence showing that under many circumstances different relationships that share features can be learned independently, and animals can quickly switch between expressing one or another. We will call this multiple-state learning. Theoretically, it is understudied because it needs a different data analysis approach from those usually employed. In this article, we present a Bayesian model of the Partial Reinforcement Extinction Effect (PREE) that can test the predictions of the multiple-state view. This implies estimating the moment of change in the responses (from the acquisition to the extinction performance), both at the individual and group levels. We used this model to analyze data from a PREE experiment with three levels of reinforcement during acquisition (100%, 75% and 50%). We found differences in the estimated moment of switch between states during extinction, so that it was delayed after leaner partial reinforcement schedules. The finding is compatible with the multiple-state view. It is the first time, to our knowledge, that the predictions from the multiple-state view are tested directly. The article also aims to show the benefits that Bayesian methods can bring to the associative learning field.
12
Elliott, Terry. "First Passage Time Memory Lifetimes for Multistate, Filter-Based Synapses." Neural Computation 32, no. 6 (June 2020): 1069–143. http://dx.doi.org/10.1162/neco_a_01283.
Full textAbstract:
Models of associative memory with discrete state synapses learn new memories by forgetting old ones. In contrast to non-integrative models of synaptic plasticity, models with integrative, filter-based synapses exhibit an initial rise in the fidelity of recall of stored memories. This rise to a peak is driven by a transient process and is then followed by a return to equilibrium. In a series of papers, we have employed a first passage time (FPT) approach to define and study memory lifetimes, incrementally developing our methods, from both simple and complex binary-strength synapses to simple multistate synapses. Here, we complete this work by analyzing FPT memory lifetimes in multistate, filter-based synapses. To achieve this, we integrate out the internal filter states so that we can work with transitions only in synaptic strength. We then generalize results on polysynaptic generating functions from binary strength to multistate synapses, allowing us to examine the dynamics of synaptic strength changes in an ensemble of synapses rather than just a single synapse. To derive analytical results for FPT memory lifetimes, we partition the synaptic dynamics into two distinct phases: the first, pre-peak phase studied with a drift-only approximation, and the second, post-peak phase studied with approximations to the full strength transition probabilities. These approximations capture the underlying dynamics very well, as demonstrated by the extremely good agreement between results obtained by simulating our model and results obtained from the Fokker-Planck or integral equation approaches to FPT processes.
13
Kottemann, Pascal, Anja Plumeyer, and Reinhold Decker. "Investigating feedback effects in the field of brand extension using brand concept maps." Baltic Journal of Management 13, no. 1 (January 2, 2018): 41–64. http://dx.doi.org/10.1108/bjm-02-2017-0031.
Full textAbstract:
Purpose The purpose of this paper is to apply the (advanced) brand concept maps (BCM) approach to reinvestigate previous findings on feedback effects resulting from brand extension information (BEI) and to explore whether this information affects the structure of a brand’s associative network. Design/methodology/approach This research builds on the associative network memory model, as well as Keller’s conceptualization of customer-based brand equity, and uses a series of empirical studies with a total of 839 respondents in two different countries. Findings The findings reveal that BEI has no significant impact on the structure of the parent brand’s associative network at the individual level. Furthermore, key brand image dimensions (i.e. favorability, strength, and uniqueness of brand associations) are not affected. Research limitations/implications By applying the (advanced) BCM approach, this paper is able to address shortcomings that are incorporated with the use of Likert scales for measuring a brand’s image and for investigating feedback effects in the field of brand extension. As the results indicate that the identification of feedback effects might be influenced by the approach used to measure a brand’s image, this paper calls for further investigations of feedback effects on a brand’s image. Originality/value Data from three empirical studies provide insights into the cognitive processing of BEI and their impact on a brand’s associative network.
14
Uemori, Takeshi, Hiroshi Miyake, Tetsuo Naka, Michihiro Takiguchi, and Fusahito Yoshida. "Finite Element Analysis of High Tensile Strength Steel Sheet by Using Complex Step Derivative Approximations." Key Engineering Materials 626 (August 2014): 187–92. http://dx.doi.org/10.4028/www.scientific.net/kem.626.187.
Full textAbstract:
The framework for the complex step derivative approximations (hereafter CDSA) to calculate the consistent tangent moduli is studied. The present methods is one of the most effective methods to implement any material constitutive equations to the commercial finite element codes and does not suffer from calculation conditions and errors. In order to confirm the efficiency of CDSA, we developed the user subroutine code based on the CDSA using associative J2 flow rules with general nonlinear isotropic hardening rules that is commonly and widely utilized in commercial finite element codes. In this study, the user material subroutine ‘Hypela2’ of MSC.Marc (ver.2013.0.0) was utilized. The finite element calculation result by the proposal method shows a good agreement with the corresponding result by the MSC.Marc default setting. Also we apply the Yoshida-Uemori back stress model to the CDSA and evaluate this new technique to predict the deformation behavior of high tensile strength steel sheet.
15
H. Akhaveissy, A. "The DSC Model for the Nonlinear Analysis of In-plane Loaded Masonry Structures." Open Civil Engineering Journal 6, no. 1 (November 16, 2012): 200–214. http://dx.doi.org/10.2174/1874149501206010200.
Full textAbstract:
A nonlinear finite element method with eight-noded isoparametric quadrilateral elements is used to predict the behavior of unreinforced masonry structures. The disturbed state concept (DSC) with modified hierarchical single yield surface (HISS) plasticity which is called DSC/HISS-CT is used to characterize the constitutive behavior of masonry in both compression and tension. The model uses two HISS yield surfaces for compressive and tensile behavior. The DSC model allows for the characterization of non-associative behavior through the use of disturbance. It computes microcrack-ing during deformation, which eventually leads to fracture and failure. the critical disturbance, Dc, identifies fracture and failure. In the DSC model the DSC model was validated at two levels: (1) specimen and (2) practical boundary value problem. At the specimen level, predictions are obtained by integrating the incremental constitutive relations. The pro-posed constitutive model is verified by comparing numerical predictions with results obtained from test data; the compari-sons are found to be highly satisfactory. A new explicit formula is also presented to estimate the strength of unreinforced masonry structures.
16
Zhao, Zenghui, Wei Sun, Shaojie Chen, Yuanhui Feng, and Weiming Wang. "Displacement of surrounding rock in a deep circular hole considering double moduli and strength-stiffness degradation." Applied Mathematics and Mechanics 41, no. 12 (October 21, 2020): 1847–60. http://dx.doi.org/10.1007/s10483-020-2665-9.
Full textAbstract:
AbstractThe problem of cavity stability widely exists in deep underground engineering and energy exploitation. First, the stress field of the surrounding rock under the uniform stress field is deduced based on a post-peak strength drop model considering the rock’s characteristics of constant modulus and double moduli. Then, the orthogonal non-associative flow rule is used to establish the displacement of the surrounding rock under constant modulus and double moduli, respectively, considering the stiffness degradation and dilatancy effects in the plastic region and assuming that the elastic strain in the plastic region satisfies the elastic constitutive relationship. Finally, the evolution of the displacement in the surrounding rock is analyzed under the effects of the double moduli characteristics, the strength drop, the stiffness degradation, and the dilatancy. The results show that the displacement solutions of the surrounding rock under constant modulus and double moduli have a unified expression. The coefficients of the expression are related to the stress field of the original rock, the elastic constant of the surrounding rock, the strength parameters, and the dilatancy angle. The strength drop, the stiffness degradation, and the dilatancy effects all have effects on the displacement. The effects can be characterized by quantitative relationships.
17
COQUEREAUX, R., G. ESPOSITO FARÈSE, and F. SCHECK. "NONCOMMUTATIVE GEOMETRY AND GRADED ALGEBRAS IN ELECTROWEAK INTERACTIONS." International Journal of Modern Physics A 07, no. 26 (October 20, 1992): 6555–93. http://dx.doi.org/10.1142/s0217751x9200301x.
Full textAbstract:
The Standard Model of Electroweak Interactions can be described by a generalized Yang-Mills field incorporating both the usual gauge bosons and the Higgs fields. The graded derivative by means of which the Yang-Mills field strength is constructed involves both a differential acting on space-time and a differential acting on an associative graded algebra of matrices. The square of the curvature for the corresponding covariant derivative yields the bosonic Lagrangian of the Standard Model. We show how to recover the whole fermionic part of the Standard Model in this framework. Quarks and leptons fit naturally into the smallest typical and nontypical irreducible representations of the graded algebra Lie SU(2|1) associated with the above associative ℤ2-graded algebra. The existence of reducible indecomposable representations leads naturally to flavor mixing in the quark sector, possibility of existence for a right neutrino and possible mixing in the leptonic sector. We therefore bridge the gap between noncommutative geometry and graded Lie algebras. The Z2 grading refers to left and right chiralities in the fermionic sector and to even and odd forms in the bosonic sector. Supergauge transformations could only be defined in an extension of the theory incorporating tensor fields of higher rank. The Standard Model contains only one-forms and zero-forms in the bosonic sector, therefore only the even part of the above graded Lie algebra — i.e. Lie[SU(2)×U(1)] — acts.
18
Lefebvre, Etienne, and Amedeo D’Angiulli. "Imagery-Mediated Verbal Learning Depends on Vividness–Familiarity Interactions: The Possible Role of Dualistic Resting State Network Activity Interference." Brain Sciences 9, no. 6 (June 18, 2019): 143. http://dx.doi.org/10.3390/brainsci9060143.
Full textAbstract:
Using secondary database analysis, we tested whether the (implicit) familiarity of eliciting noun-cues and the (explicit) vividness of corresponding imagery exerted additive or interactive influences on verbal learning, as measured by the probability of incidental noun recall and image latency times (RTs). Noun-cues with incongruent levels of vividness and familiarity (high/low; low/high, respectively) at encoding were subsequently associated at retrieval with the lowest recall probabilities, while noun-cues related with congruent levels (high/high; low/low) were associated with higher recall probabilities. RTs in the high vividness and high familiarity grouping were significantly faster than all other subsets (low/low, low/high, high/low) which did not significantly differ among each other. The findings contradict: (1) associative theories predicting positive monotonic relationships between memory strength and learning; and (2) non-monotonic plasticity hypothesis (NMPH), aiming at generalizing the non-monotonic relationship between a neuron’s excitation level and its synaptic strength to broad neural networks. We propose a dualistic neuropsychological model of memory consolidation that mimics the global activity in two large resting-state networks (RSNs), the default mode network (DMN) and the task-positive-network (TPN). Based on this model, we suggest that incongruence and congruence between vividness and familiarity reflect, respectively, competition and synergy between DMN and TPN activity. We argue that competition or synergy between these RSNs at the time of stimulus encoding disproportionately influences long term semantic memory consolidation in healthy controls. These findings could assist in developing neurophenomenological markers of core memory deficits currently hypothesized to be shared across multiple psychopathological conditions.
19
Pauli, Wolfgang M., Thomas E. Hazy, and Randall C. O'Reilly. "Expectancy, Ambiguity, and Behavioral Flexibility: Separable and Complementary Roles of the Orbital Frontal Cortex and Amygdala in Processing Reward Expectancies." Journal of Cognitive Neuroscience 24, no. 2 (February 2012): 351–66. http://dx.doi.org/10.1162/jocn_a_00155.
Full textAbstract:
Appetitive goal-directed behavior can be associated with a cue-triggered expectancy that it will lead to a particular reward, a process thought to depend on the OFC and basolateral amygdala complex. We developed a biologically informed neural network model of this system to investigate the separable and complementary roles of these areas as the main components of a flexible expectancy system. These areas of interest are part of a neural network with additional subcortical areas, including the central nucleus of amygdala, ventral (limbic) and dorsomedial (associative) striatum. Our simulations are consistent with the view that the amygdala maintains Pavlovian associations through incremental updating of synaptic strength and that the OFC supports flexibility by maintaining an activation-based working memory of the recent reward history. Our model provides a mechanistic explanation for electrophysiological evidence that cue-related firing in OFC neurons is nonselectively early after a contingency change and why this nonselective firing is critical for promoting plasticity in the amygdala. This ambiguous activation results from the simultaneous maintenance of recent outcomes and obsolete Pavlovian contingencies in working memory. Furthermore, at the beginning of reversal, the OFC is critical for supporting responses that are no longer inappropriate. This result is inconsistent with an exclusive inhibitory account of OFC function.
20
Wang, Wenling, and Daniel Korschun. "Spillover of social responsibility associations in a brand portfolio." Journal of Product & Brand Management 24, no. 6 (September 21, 2015): 596–609. http://dx.doi.org/10.1108/jpbm-06-2014-0629.
Full textAbstract:
Purpose – This paper aims to explore the spillover effect of social responsibility (SR) activity at the product brand level on the full brand portfolio. Extant research has established that SR activity can be beneficial to companies by influencing consumers’ SR associations with the company and its product brands. However, most studies only look at the outcomes of SR implemented at the corporate level (i.e. corporate social responsibility [CSR]). This paper provides a new and expanded perspective by exploring how SR at the product brand level reverberates throughout the full brand portfolio. Drawing on associative network theory, the authors propose a conceptual model that predicts when and how SR associations with a product brand spillover to corporate brand and other product brands and the consequences of this spillover. Design/methodology/approach – Two experiments were conducted to test the conceptual model. The authors used utilitarian products (frozen yogurt, ice cream, and soft drink) in the first experiment and value-expressive products (running shoes, T-shirt and watch) in the second experiment. Findings – Both experiments found support for the proposed spillover effect. The moderating impact of corporate branding strategy and product category fit on the strength of spillover effect were also examined. Practical implications – The findings will help managers make better decisions about which brands (product and corporate level) should be involved in SR activity. Originality/value – This research offers a new perspective to look at the consequences of SR activity and reveals a larger picture than extant research on CSR by indicating the impact of a product brand’s SR initiative on the whole brand portfolio.
21
FOMIN, TIBOR, TAMÁS ROZGONYI, CSABA SZEPESVÁRI, and ANDRÁS LŐRINCZ. "SELF-ORGANIZING MULTI-RESOLUTION GRID FOR MOTION PLANNING AND CONTROL." International Journal of Neural Systems 07, no. 06 (December 1996): 757–76. http://dx.doi.org/10.1142/s0129065796000713.
Full textAbstract:
A fully self-organizing neural network approach to low-dimensional control problems is described. We consider the problem of learning to control an object and solving the path planning problem at the same time. Control is based on the path planning model that follows the gradient of the stationary solution of a diffusion process working in the state space. Previous works are extended by introducing a self-organizing multigrid-like discretizing structure to represent the external world. Diffusion is simulated within a recurrent neural network built on this multigrid system. The novelty of the approach is that the diffusion on the multigrid is fast. Moreover, the diffusion process on the multigrid fits well the requirements of the path planning: it accelerates the diffusion in large free space regions while still keeps the resolution in small bottleneck-like labyrinths along the path. Control is achieved in the usual way: associative learning identifies the inverse dynamics of the system in a direct fashion. To this end there are introduced interneurons between neighboring discretizing units that detect the strength of the steady-state diffusion and forward control commands to the control neurons via modifiable connections. This architecture forms the Multigrid Position-and-Direction-to-Action (MPDA) map. The architecture integrates reactive path planning and continuous motion control. It is also shown that the scheme leads to population coding for the actual command vector.
22
Magotra, Arjun, and Juntae Kim. "Improvement of Heterogeneous Transfer Learning Efficiency by Using Hebbian Learning Principle." Applied Sciences 10, no. 16 (August 13, 2020): 5631. http://dx.doi.org/10.3390/app10165631.
Full textAbstract:
Transfer learning algorithms have been widely studied for machine learning in recent times. In particular, in image recognition and classification tasks, transfer learning has shown significant benefits, and is getting plenty of attention in the research community. While performing a transfer of knowledge among source and target tasks, homogeneous dataset is not always available, and heterogeneous dataset can be chosen in certain circumstances. In this article, we propose a way of improving transfer learning efficiency, in case of a heterogeneous source and target, by using the Hebbian learning principle, called Hebbian transfer learning (HTL). In computer vision, biologically motivated approaches such as Hebbian learning represent associative learning, where simultaneous activation of brain cells positively affect the increase in synaptic connection strength between the individual cells. The discriminative nature of learning for the search of features in the task of image classification fits well to the techniques, such as the Hebbian learning rule—neurons that fire together wire together. The deep learning models, such as convolutional neural networks (CNN), are widely used for image classification. In transfer learning, for such models, the connection weights of the learned model should adapt to new target dataset with minimum effort. The discriminative learning rule, such as Hebbian learning, can improve performance of learning by quickly adapting to discriminate between different classes defined by target task. We apply the Hebbian principle as synaptic plasticity in transfer learning for classification of images using a heterogeneous source-target dataset, and compare results with the standard transfer learning case. Experimental results using CIFAR-10 (Canadian Institute for Advanced Research) and CIFAR-100 datasets with various combinations show that the proposed HTL algorithm can improve the performance of transfer learning, especially in the case of a heterogeneous source and target dataset.
23
Zou, Qingrong, Kai Song, and Jian Shi. "A Bayesian In-Play Prediction Model for Association Football Outcomes." Applied Sciences 10, no. 8 (April 22, 2020): 2904. http://dx.doi.org/10.3390/app10082904.
Full textAbstract:
Point process models have made a significant contribution to the prediction of football association outcomes. It is conventionally the case that defence and attack capabilities have been assumed to be constant during a match and estimated against the average performance of all other teams in history. Drawing upon a Bayesian method, this paper proposes a dynamic strength model which relaxes assumption of the constant teams’ strengths and permits applying in-match performance information to calibrate them. An empirical study demonstrates that although the Bayesian model fails to achieve improvement in goal difference prediction, it registers clear achievements with regard to the prediction of the total number of goals and Win/Draw/Loss outcome prediction. When the Bayesian model bets against the SBOBet bookmaker, one of the most popular gaming companies among Asian handicaps fans, whose odds data were obtained from both the Win/Draw/Loss market and over–under market, it may obtain positive returns; this clearly contrasts with the process model with constant strengths, which fails to win money from the bookmaker.
24
Ahmed, A. N., and A. A. Alzaid. "Weak association with a stress-strength model application." Statistics & Probability Letters 8, no. 1 (May 1989): 91–95. http://dx.doi.org/10.1016/0167-7152(89)90090-4.
Full text
25
Aravindakshan, Vinish, Faisal F. Hakeem, and Wael Sabbah. "Periodontal Disease and Grip Strength among Older Adults." Geriatrics 5, no. 3 (August 26, 2020): 46. http://dx.doi.org/10.3390/geriatrics5030046.
Full textAbstract:
Objective: The aim of this research was to assess the association between periodontitis and grip strength among older American adults. Methods: Data from the National Health and Nutrition Examination Survey 2011/2012 and 2013/2014 were used. Oral health status and hand grip strength were clinically assessed. Three outcome variables were used: (1) handgrip strength <30 kg for men, <20 kg for women; (2) handgrip strength <26 kg for men, <16 kg for women; and (3) mean maximum grip strength. The main exposure was the case definition of periodontitis. Logistic and linear regression models were constructed for grip strength definitions and the mean grip strength, respectively, adjusting for covariates. Results: The study included 1953 participants. The mean age was 68.5 years, and 47.2% were males. The prevalence of low grip strength (<30 kg for men, <20 kg for women) was 7.4% in men and 13.6% in women. Periodontitis was significantly associated with grip strength (OR 1.53, 95% CI: 1.03, 2.27) in the unadjusted model. Periodontitis was also significantly associated with maximum grip strength (Coefficient 1.05, 95% CI −1.99, −0.09) in a model adjusted for age and gender. However, in all the fully adjusted models there was no statistically significant association between periodontitis and grip strength. Conclusion: Low grip strength appeared to be more common among persons with moderate/severe periodontitis. The observed association is probably attributed to older age and common risk factors for periodontitis and frailty.
26
Zhu, Qiao, Lin Hua Jiang, and Jin Xia Xu. "A Review of Strength Models in Association with Pore Structure of Cement-Based Materials." Advanced Materials Research 287-290 (July 2011): 862–67. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.862.
Full textAbstract:
In this article, some empirical and theoretical models accounting the relationship between the strength and pore structure of cement-based materials is reviewed and analyzed. From the literature review and analysis, it can be found that the total porosity can be singly used to characterize the relationship between compressive strength and pore structure, but can not be applied into describe the relationship between pore structure and tensile strength. Another major parameter of pore structure - pore size distribution, will have a major impact on strength; the relationship between pore structure and tensile strength is for most models of cement paste, without the consideration of aggregate, and the application of the model must comply with the relevant assumptions. The research on the relationship between the tensile strength of concrete is still at a preliminary stage, requiring more theoretical and experimental study.
27
Park, JungWoong, Daniel Kuchma, and Rafael Souza. "Strength predictions of pile caps by a strut-and-tie model approach." Canadian Journal of Civil Engineering 35, no. 12 (December 2008): 1399–413. http://dx.doi.org/10.1139/l08-062.
Full textAbstract:
In this paper, a strut-and-tie model approach is presented for calculating the strength of reinforced concrete pile caps. The proposed method employs constitutive laws for cracked reinforced concrete and considers strain compatibility. This method is used to calculate the load-carrying capacity of 116 pile caps that have been tested to failure in structural research laboratories. This method is illustrated to provide more accurate estimates of behavior and capacity than the special provisions for slabs and footings of the 1999 American Concrete Institute (ACI) code, the pile cap provisions in the 2002 CRSI design handbook, and the strut-and-tie model provisions in either the 2005 ACI code or the 2004 Canadian Standards Association (CSA) A23.3 standard. The comparison shows that the proposed method consistently well predicts the strengths of pile caps with shear span-to-depth ratios ranging from 0.49 to 1.8 and concrete strengths less than 41 MPa. The proposed approach provides valuable insight into the design and behavior of pile caps.
28
LEE, DONQ-LIANG, and WEN-JUNE WANG. "EQUILIBRIUM AND ATTRACTIVITY ANALYSIS FOR A CLASS OF HETERO-ASSOCIATIVE NEURAL MEMORIES." International Journal of Neural Systems 07, no. 03 (July 1996): 287–304. http://dx.doi.org/10.1142/s0129065796000269.
Full textAbstract:
Based on the natural structure of Kosko’s Bidirectional Associative Memories (BAM), a high-performance, high-capacity associative neural model is proposed which is capable of simultaneous hetero-associative recall. The proposed model, Modified Bidirectional Decoding Strategy (MBDS), improves the recall rate by adding some association fascicles to Kosko’s BAM. The association fascicles are sparse coding neuron structures that provide activating strengths between two neuron fields (say, field X and field Y). The sufficient conditions for a state to become an equilibrium state of the MBDS network is derived. Based on these results, we discuss the basins of attraction of the training pairs in one iteration. The upper bound of the number of error bits which can be tolerated by MBDS is also derived. Because the attractivity of a stored training pair can be increased markedly with the aid of its corresponding association fascicles, we recommend a high capacity realization of MBDS, Bidirectional Holographic Memory (BHM), so that each training pair is stored uniquely and directly in the connection weights rather than encoded in a correlation matrix. Finally, computer simulations demonstrate the attractiveness of three different realizations of MBDS to verify our results.
29
Al-Zaid, Rajeh Z., and Andrzej S. Nowak. "Fatigue strength of prestressed concrete girder bridges." Canadian Journal of Civil Engineering 15, no. 2 (April 1, 1988): 199–205. http://dx.doi.org/10.1139/l88-027.
Full textAbstract:
A model for evaluating the fatigue life of a prestressed concrete girder bridge is presented. Experimental studies indicate that fatigue is a random phenomenon. Therefore, the approach is based on probabilistic methods. The fatigue life of the prestressed concrete girder is estimated from the fatigue properties of its components, namely, the cast-in-place slab, precast beam, prestressing steel, and, if partially prestressed, the tension reinforcement. The model utilizes the available S–N curves for structural materials and Miner's rule to evaluate the fatigue life under variable amplitude loading. A model for determining the distribution function of time to first cracking is also presented. To demonstrate the developed models, a typical prestressed concrete girder bridge is analyzed. On the basis of this investigation, it is concluded that fatigue in prestressed concrete girder bridges designed according to the American Association of State Highway and Transportation Officials specifications is not a limiting design criterion. Key words: bridges, fatigue, prestressed concrete, structural reliability.
30
Shaffer, David Williamson, Wesley Collier, and A. R. Ruis. "A Tutorial on Epistemic Network Analysis: Analyzing the Structure of Connections in Cognitive, Social, and Interaction Data." Journal of Learning Analytics 3, no. 3 (December 19, 2016): 9–45. http://dx.doi.org/10.18608/jla.2016.33.3.
Full textAbstract:
This paper provides a tutorial on epistemic network analysis (ENA), a novel method for identifying and quantifying connections among elements in coded data and representing them in dynamic network models. Such models illustrate the structure of connections and measure the strength of association among elements in a network, and they quantify changes in the composition and strength of connections over time. Importantly, ENA enables comparison of networks both directly and via summary statistics, so the method can be used to explore a wide range of qualitative and quantitative research questions in situations where patterns of association in data are hypothesized to be meaningful. While ENA was originally developed to model cognitive networks—the patterns of association between knowledge, skills, values, habits of mind, and other elements that characterize complex thinking—ENA is a robust method that can be used to model patterns of association in any system characterized by a complex network of dynamic relationships among a relatively small, fixed set of elements.
31
Bawadi, Hiba, Dana Alkhatib, Haya Abu-Hijleh, Joud Alalwani, Lina Majed, and Zumin Shi. "Muscle Strength and Glycaemic Control among Patients with Type 2 Diabetes." Nutrients 12, no. 3 (March 14, 2020): 771. http://dx.doi.org/10.3390/nu12030771.
Full textAbstract:
Poor glycaemic control is associated with chronic life-threatening complications. This cross-sectional study examined whether there is an association between handgrip strength and glycaemic control among patients with diabetes. Data on 1058 participants aged 40 and older were collected from the National Health and Nutritional Examination Survey (NHANES). Muscle strength was assessed using a handgrip dynamometer, and glycaemic control was assessed using HbA1c. Handgrip strength was presented as age- and gender-specific quartiles, with participants in quartile 1 having the lowest handgrip strength and participants in quartile 4 having the highest handgrip strength. Logistic regression analyses were used to assess the association between handgrip strength and poor glycaemic control among participants with diabetes. Three models, each adjusted to include different variables, were employed. Odds ratio (OR) values revealed no association between handgrip strength and glycaemic control after adjusting for age, gender, and race in model 1. With further adjustment for sedentary activity, income-to-poverty ratio, education, and smoking, patients in quartile 4 of handgrip strength had 0.51 odds of poor glycaemic control (95% CI: 0.27–0.99). However, the reported association above vanished when further adjusted for insulin use (OR = 0.67; 95% CI: 0.35–1.28). In conclusion, findings may indicate an association between glycaemic control and muscle strength. This association may be altered by insulin use; further investigations are required.
32
Huang, Jing, Xiaogang Ruan, Naigong Yu, Qingwu Fan, Jiaming Li, and Jianxian Cai. "A Cognitive Model Based on Neuromodulated Plasticity." Computational Intelligence and Neuroscience 2016 (2016): 1–15. http://dx.doi.org/10.1155/2016/4296356.
Full textAbstract:
Associative learning, including classical conditioning and operant conditioning, is regarded as the most fundamental type of learning for animals and human beings. Many models have been proposed surrounding classical conditioning or operant conditioning. However, a unified and integrated model to explain the two types of conditioning is much less studied. Here, a model based on neuromodulated synaptic plasticity is presented. The model is bioinspired including multistored memory module and simulated VTA dopaminergic neurons to produce reward signal. The synaptic weights are modified according to the reward signal, which simulates the change of associative strengths in associative learning. The experiment results in real robots prove the suitability and validity of the proposed model.
33
Hamby, Sherry, Elizabeth Taylor, Kimberly Mitchell, Lisa Jones, and Chris Newlin. "Is it better to seek or to receive? A dual-factor model of social support." International Journal of Child and Adolescent Resilience 7, no. 1 (October 27, 2020): 5–17. http://dx.doi.org/10.7202/1072584ar.
Full textAbstract:
Objectives: This study adopts a dual-factor approach to examine the association of seeking and receiving social support with 6 indicators of current functioning and 14 psychosocial strengths.
Methods: A survey completed by 440 youth ages 10 to 21 (M = 16.38, SD = 3.04) assessed strengths, functioning, and victimization. Youth were classified into four groups: Interconnected (high on social support seeking and receiving; 33% of sample), Rebuffed (high on social support seeking, low on social support receiving; 12%), Tended (low on social support seeking, high on social support receiving; 16%), and Isolated (low on social support seeking and receiving; 39%).
Results: Controlling for age, gender, and victimization, the social support group was associated with each meaning making, regulatory, and interpersonal strength, and every indicator of current functioning except trauma symptoms. The Isolated group scored lowest on all measures and the Interconnected group scored highest on 19 of 20 measures. The mixed profile groups fell between these extremes. Notably, the Rebuffed group reported higher levels of some strengths and non-theistic spiritual well-being than the Tended group. The Tended group was never significantly higher than the Rebuffed group.
Implications: Individual skills and attitudes regarding helpseeking may be more impactful than social support provided by others. Rebuffed youth may be steeling themselves in other strengths when the social environment is not supportive.
34
Tepavitcharova, Stefka, Diana Rabadjieva, Tihomir Todorov, Antonina Kovacheva, Manos Dassenakis, and Vasiliki Paraskevopoulou. "Chemical speciation in fresh, saline and hyper-saline waters." Pure and Applied Chemistry 86, no. 7 (July 22, 2014): 1097–104. http://dx.doi.org/10.1515/pac-2014-0107.
Full textAbstract:
AbstractA thermodynamic model is proposed, which combines the ion association and the ion interaction models using the extended database pit2010.dat for a more precise modeling of the chemical species of micro components in natural waters of varying ionic strength (fresh, saline and hyper-saline). Compared to the ion association model, the proposed combined model more adequately describes the complex character of the ionic interactions. The performance of the combined ion association/ion interaction model compared to that of the ion association model is illustrated in case studies of several Bulgarian natural water systems of different ionic strength and type of pollution. The results are interpreted in terms of the chemical behavior of the metals and of their chemical species in the water systems, which is defined by the redox potential, pH, cationic and anionic organic and inorganic composition of the water systems and by the ability of the metals to preferentially coordinate with some anions, as well as by the stability of the corresponding species. The affinity of the transition metals towards the ligands is explained by the “hardness-softness” factor and the crystal field stabilization energy (CFSE).
35
Andrinopoulou, Eleni-Rosalina, Kazem Nasserinejad, Rhonda Szczesniak, and Dimitris Rizopoulos. "Integrating latent classes in the Bayesian shared parameter joint model of longitudinal and survival outcomes." Statistical Methods in Medical Research 29, no. 11 (May 21, 2020): 3294–307. http://dx.doi.org/10.1177/0962280220924680.
Full textAbstract:
Cystic fibrosis is a chronic lung disease requiring frequent lung-function monitoring to track acute respiratory events (pulmonary exacerbations). The association between lung-function trajectory and time-to-first exacerbation can be characterized using joint longitudinal-survival modeling. Joint models specified through the shared parameter framework quantify the strength of association between such outcomes but do not incorporate latent sub-populations reflective of heterogeneous disease progression. Conversely, latent class joint models explicitly postulate the existence of sub-populations but do not directly quantify the strength of association. Furthermore, choosing the optimal number of classes using established metrics like deviance information criterion is computationally intensive in complex models. To overcome these limitations, we integrate latent classes in the shared parameter joint model through a fully Bayesian approach. To choose the optimal number of classes, we construct a mixture model assuming more latent classes than present in the data, thereby asymptotically “emptying” superfluous latent classes, provided the Dirichlet prior on class proportions is sufficiently uninformative. Model properties are evaluated in simulation studies. Application to data from the US Cystic Fibrosis Registry supports the existence of three sub-populations corresponding to lung-function trajectories with high initial forced expiratory volume in 1 s ( FEV1), rapid FEV1 decline, and low but steady FEV1 progression. The association between FEV1 and hazard of exacerbation was negative in each class, but magnitude varied.
36
Zolotukhin, I. N. "АСЕАН как уникальная модель регионализма." Известия Восточного института 45, no. 1 (2020): 121–27. http://dx.doi.org/10.24866/2542-1611/2020-1/121-127.
Full textAbstract:
Статья представляет собой рецензию на коллективную монографию «Сообщество АСЕАН в современном мире», изданную Центром изучения Вьетнама и АСЕАН Института Дальнего Востока РАН и посвящённую Ассоциации государств Юго-Восточной Азии (АСЕАН) как модели региональной интеграции, её роли и значению в международных отношениях. В рецензии отражены проблемы становления организации и её превращения в актора регионального масштаба, рассмотрена эволюция ассоциации в Сообщество АСЕАН, даётся оценка политическому наследию АСЕАН, а также её отношениям с диалоговыми партнёрами в условиях нарастания противоречий в Юго-Восточной Азии. The article reviews the book «ASEAN Community in the Modern World», published by a group of scholars of the Center for the Vietnam and ASEAN Studies of the Institute of Far Eastern Studies of the Russian Academy of Sciences and dedicated to the Association of Southeast Asian Nations (ASEAN) as a model of regional integration. In the book the role and significance of this organization in international relations is clarified. The review reflects the prerequisites of the formation of the organization, the main stages of its development and its transformation into a pivotal actor of regional scale, considers the evolution of the association into the ASEAN Community, assesses the political heritage of ASEAN, as well as its relations with dialogue partners in the face of growing contradictions in Southeast Asia where the rivalry between China as a rising power, expanding its influence in regional issues, and the United States, making great efforts to strengthen their positions, is escalating
37
Brunel, Nicolas, and Frédéric Lavigne. "Semantic Priming in a Cortical Network Model." Journal of Cognitive Neuroscience 21, no. 12 (December 2009): 2300–2319. http://dx.doi.org/10.1162/jocn.2008.21156.
Full textAbstract:
Contextual recall in humans relies on the semantic relationships between items stored in memory. These relationships can be probed by priming experiments. Such experiments have revealed a rich phenomenology on how reaction times depend on various factors such as strength and nature of associations, time intervals between stimulus presentations, and so forth. Experimental protocols on humans present striking similarities with pair association task experiments in monkeys. Electrophysiological recordings of cortical neurons in such tasks have found two types of task-related activity, “retrospective” (related to a previously shown stimulus), and “prospective” (related to a stimulus that the monkey expects to appear, due to learned association between both stimuli). Mathematical models of cortical networks allow theorists to understand the link between the physiology of single neurons and synapses, and network behavior giving rise to retrospective and/or prospective activity. Here, we show that this type of network model can account for a large variety of priming effects. Furthermore, the model allows us to interpret semantic priming differences between the two hemispheres as depending on a single association strength parameter.
38
Goldman, Nick, Jeffrey L. Thorne, and David T. Jones. "Assessing the Impact of Secondary Structure and Solvent Accessibility on Protein Evolution." Genetics 149, no. 1 (May 1, 1998): 445–58. http://dx.doi.org/10.1093/genetics/149.1.445.
Full textAbstract:
Abstract Empirically derived models of amino acid replacement are employed to study the association between various physical features of proteins and evolution. The strengths of these associations are statistically evaluated by applying the models of protein evolution to 11 diverse sets of protein sequences. Parametric bootstrap tests indicate that the solvent accessibility status of a site has a particularly strong association with the process of amino acid replacement that it experiences. Significant association between secondary structure environment and the amino acid replacement process is also observed. Careful description of the length distribution of secondary structure elements and of the organization of secondary structure and solvent accessibility along a protein did not always significantly improve the fit of the evolutionary models to the data sets that were analyzed. As indicated by the strength of the association of both solvent accessibility and secondary structure with amino acid replacement, the process of protein evolution—both above and below the species level—will not be well understood until the physical constraints that affect protein evolution are identified and characterized.
39
Yang, Zhutian, Eng Hooi Tan, Yingda Li, Brian Lim, Michael Patrick Metz, and Tze Ping Loh. "Relative criticalness of common laboratory tests for critical value reporting." Journal of Clinical Pathology 72, no. 4 (December 28, 2018): 325–28. http://dx.doi.org/10.1136/jclinpath-2018-205549.
Full textAbstract:
We determined the relative strengths of association between 23 most commonly ordered laboratory tests and the adverse outcome as indicators of relative criticalness. The lowest and highest results for 23 most commonly ordered laboratory tests, 24 hours prior to death during critical care unit (CCU) stay or discharge from CCU were extracted from a publicly available CCU database (Medical Information Mart for Intensive Care-III). Following this, the Random Forest model was applied to assess the association between the laboratory results and the outcomes (death or discharge). The mean decrease in Gini coefficient for each laboratory test was then ranked as an indication of their relative importance to the outcome of a patient. In descending order, the 10 laboratory tests with the strongest association with death were: bicarbonate, phosphate, anion gap, white cell count (total), partial thromboplastin time, platelet, total calcium, chloride, glucose and INR; moreover, the strength of association was different for critically high versus low results.
40
Valiant, Leslie G. "Memorization and Association on a Realistic Neural Model." Neural Computation 17, no. 3 (March 1, 2005): 527–55. http://dx.doi.org/10.1162/0899766053019890.
Full textAbstract:
A central open question of computational neuroscience is to identify the data structures and algorithms that are used in mammalian cortex to support successive acts of the basic cognitive tasks of memorization and association. This letter addresses the simultaneous challenges of realizing these two distinct tasks with the same data structure, and doing so while respecting the following four basic quantitative parameters of cortex: the neuron number, the synapse number, the synapse strengths, and the switching times. Previous work has not succeeded in reconciling these opposing constraints, the low values of synapse strengths that are typically observed experimentally having contributed a particular obstacle. In this article, we describe a computational scheme that supports both memory formation and association and is feasible on networks of model neurons that respect the widely observed values of the four quantitative parameters. Our scheme allows for both disjoint and shared representations. The algorithms are simple, and in one version both memorization and association require just one step of vicinal or neighborly influence. The issues of interference among the different circuits that are established, of robustness to noise, and of the stability of the hierarchical memorization process are addressed. A calculus therefore is implied for analyzing the capabilities of particular neural systems and subsystems, in terms of their basic numerical parameters.
41
Koeckhoven, Esmee, Marike van der Leeden, Leo D. Roorda, Natasja M. van Schoor, Paul Lips, Arjan de Zwart, Joost Dekker, Martin van der Esch, and Willem F. Lems. "The Association Between Serum 25-hydroxy Vitamin D Level and Upper Leg Strength in Patients with Knee Osteoarthritis: Results of the Amsterdam Osteoarthritis Cohort." Journal of Rheumatology 43, no. 7 (May 15, 2016): 1400–1405. http://dx.doi.org/10.3899/jrheum.150751.
Full textAbstract:
Objective.Vitamin D deficiency, which is common among elderly people, has been linked to muscle weakness. In patients with knee osteoarthritis (OA), the association between muscle strength and serum 25-hydroxy Vitamin D [25(OH)D] level has not been studied comprehensively. The aim of our study was to examine the association between serum 25(OH)D level and muscle strength in patients with knee OA.Methods.Data of the Amsterdam Osteoarthritis cohort from 319 participants with knee OA were used in a cross-sectional study. Serum 25(OH)D level (nmol/l) was measured by a competitive electrochemiluminescence method. Muscle strength (nm/kg) of the upper leg was measured isokinetically. Univariable and multivariable linear regression analyses were used to calculate the association between serum 25(OH)D level and muscle strength.Results.Serum 25(OH)D level was significantly associated with muscle strength (B = 0.036, 95% CI 0.017–0.054, p < 0.001), adjusted for season of blood collection. After adding body mass index (BMI) to the model, this association was no longer significant (B = 0.011, 95% CI −0.007 to 0.029, p = 0.214). Alcohol consumption, number of comorbidities, and sex were subsequently added and changed the model slightly. Without BMI, this model showed a significant association between serum 25(OH)D level and muscle strength (B = 0.029, 95% CI 0.014–0.043, p < 0.001).Conclusion.The observed association between a low serum 25(OH)D level and muscle weakness in patients with knee OA is attenuated by BMI. Further studies are needed to explain the associations among Vitamin D level, muscle strength, and adiposity in patients with knee OA.
42
Kennedy, Teri. "STRENGTH IN AGE-FRIENDLY HEALTH SYSTEMS: AN INNOVATIVE INTEGRATED INTERPROFESSIONAL MODEL." Innovation in Aging 3, Supplement_1 (November 2019): S829. http://dx.doi.org/10.1093/geroni/igz038.3054.
Full textAbstract:
Abstract This paper presents an innovative conceptual approach to health care policy for older adults: the Age-Friendly Health Systems Integrated Interprofessional Model. In 2017, the John A. Hartford Foundation and Institute for Healthcare Improvement, in partnership with the American Hospital Association and Catholic Health Association of the United States, advanced the concept of an Age-Friendly Health System. This initiative is designed to respond to the needs of a burgeoning U.S. older adult population, expected to double from 2012 to 2050, largely due to the aging of Baby Boomers and increased life expectancy. These Baby Boomers will demand a well-coordinated, communicative health system responsive to their values and preferences. In an Age-Friendly Health System, all older adults receive the best possible care, without care-related harms, and with satisfaction of care received. Essential elements include what matters, mentation, mobility, and medications, with a focus on patient-directed, family-engaged care. While a solid framework for improving healthcare for older adults, this model is further strengthened by incorporating the essential elements of person-, family-, and community-centered approaches to care; interprofessional team-based competencies, and Quadruple Aim outcomes. This enhanced model, referred to as the Age-Friendly Health System Integrated Interprofessional Model, combines elements essential to quality healthcare within the framework of an Age-Friendly Health System. This paper will present the original Age-Friendly Health System framework, the proposed Age-Friendly Health System Integrated Interprofessional Model, then compare and contrast each model’s essential principles. Implications for adoption of this enhanced model for policy, education, and practice will be explored.
43
Manik, Cornelia Dumarya. "Pengaruh Citra Merek Terhadap Keputusan Pembelian Pada PT Astra International, Tbk Toyota Auto 2000 Bumi Serpong Damai." Jurnal Al Azhar Indonesia Seri Ilmu Sosial 1, no. 2 (August 31, 2020): 111. http://dx.doi.org/10.36722/jaiss.v1i2.470.
Full textAbstract:
<p><em>Abstrak</em> - <strong>Penelitian ini bertujuan untuk mengetahui seberapa besar pengaruh citra merek terhadap keputusan pembelian pada PT. Astra International, Tbk-Toyota Auto 2000 cabang Bumi Serpong Damai. Penelitian ini dilaksanakan di PT. Astra International, Tbk-Toyota Auto 2000 cabang Bumi Srpong Damai. Model penelitian yang digunakan yakni dengan metode observasi, wawancara, kuesioner dan studi kepustakaan yang dilakukan secara sistematik berdasarkan tujuan penelitian. Metode penelitian ini menggunakan metode kuantitatif, asosiatif dengan populasi dalam penelitian ini adalah pelanggan yang melakukan service berkala pada PT. Astra International, Tbk-Toyota Auto 2000 cabang Bumi Serpong Damai, dalam waktu 5 ( lima ) tahun yaitu sebanyak 624 pelanggan. Metode penarikan sampel menggunakan rumus Slovin didapat sebanyak 86 responden. Metode analisis dalam pengolahan data adalah uji validitas dan reliabilitas, uji regresi linear sederhana, koefisien determinasi, uji hipotesis (uji-t), dan uji korelasi pearson product moment untuk mengetahui seberapa besar pengaruh citra merek terhadap keputusan pembelian mobil Toyota Yaris. Berdasarkan hasil penelitian dan pembahasan diperoleh hasil, bahwa terdapat pengaruh hubungan positif antara citra merek terhadap keputusan pembelian sebesar 0,602 sehingga adanya hubungan antara citra merek terhadap keputusan pembelian, dari hasil regresi lienar sederhana dapat dilihat persamaan yang bernilai y=16.546+0,583X. Yang memiliki arti bahwa variabel citra merek berpengaruh positif terhadap keputusan pembelian konsumen, dari hasil uji determinasi sebesar 0,362. Hal ini menunjukkan bahwa sebesar 36,2% Keputusan Pembelian konsumen terhadap pembelian mobil Toyota Yaris dipengaruhi oleh variasi dari ketiga variabel independen, yaitu keunggulan asosiasi merek, kekuatan asosiasi merek, keunikan asosiasi merek, Sedangkam sisanya sebesar 63,8% dipengaruhi oleh variabel-variabel lainnya yang tidak diteliti. Hasil t hitung adalah 6,907 lebih besar dari t tabel yaitu 1,9886. Oleh karena itu t-hitung lebih kecil daripada t-tabel, maka H0 ditolak dan Ha≠0 diterima. Ini menunjukkan bahwa antara pengaruh citra merek terhadap keputusan pembelian terdapat pengaruh yang signifikan.</strong></p><p><em><strong>Kata Kunci</strong> : Citra merek, Keputusan Pembelian.</em></p><p align="center"> </p><p><em>Abstract</em><strong> - This research was conducted on PT. Astra International, Tbk-Toyota Auto 2000 branch of Bumi Serpong Damai. The research model used is the method of observation, interviews, questionnaires and literature studies conducted systematically based on research objectives. This research method using quantitative method, associative with population in this research is customer who do periodical service on PT. Astra International Tbk-Toyota Auto 2000 branch Bumi Serpong Damai, within 5 (five) years as many as 624 customers. Sampling method using Slovin formula obtained as many as 86 respondents. Method of analysis in data processing is test of validity and reliability, simple linear regression test, coefficient of determination, hypothesis test (t- test), and Pearson product moment correlation test to find out how much the influence of the brand image of Toyota Yaris car purchase decision. Based on the results of research and discussion obtained the results, that there is influence positive relationship between the brand image to purchase decision of 0.602 so that the relationship between the brand image of the purchase decision, from the results of simple lienar regression can be seen the equation y = 16,546 + 0,583X. Which means that brand image variables have a positive effect on consumer purchasing decisions, from the test determination of 0.362. This shows that 36,2% Consumer purchasing decision on Toyota Yaris car purchase is influenced by variation from three independent variables, namely the superiority of brand association, the strength of brand association, uniqueness of brand association, the remaining cages of 63,8% influenced by the variables others not examined. Result t count is 6,907 bigger than t table that is 1,9886. Therefore t-count is smaller than t-table, then H0 is rejected and Ha ≠ 0 is accepted. This shows that between the influence of brand image to purchase decision there is a significant influence.</strong></p><p><strong><em>Keywords</em></strong> : <em>Brand image, Purchase Decision<strong>.</strong></em></p>
44
Geltner, Jill A., and Teresa N. Leibforth. "Advocacy in the IEP Process: Strengths-Based School Counseling in Action." Professional School Counseling 12, no. 2 (December 2008): 2156759X0801200. http://dx.doi.org/10.1177/2156759x0801200206.
Full textAbstract:
As the number of students in schools receiving special education services rises, the need for advocacy for these students increases as well. Because school counselors already possess specialized training beneficial to all stakeholders in the special education process, the potential for school counselors’ role in the Individualized Education Plan (IEP) process is quickly increasing. This article addresses how school counselors can collaborate with teachers and special education teams in the IEP, 504 plan, and other student support team processes. School counselors can model positive communication and assist the team in identifying student and environmental strengths while also increasing family involvement. Specific ways that school counselors can collaborate with planning teams are discussed and direct links are made to Strength-Based School Counseling (Galassi & Akos, 2007) and the ASCA National Model® (American School Counselor Association, 2005).
45
Edwards, Meghan K., and Paul D. Loprinzi. "Adequate Muscular Strength May Help to Reduce Risk of Residual-Specific Mortality: Findings From the National Health and Nutrition Examination Survey." Journal of Physical Activity and Health 15, no. 5 (May 1, 2018): 369–73. http://dx.doi.org/10.1123/jpah.2016-0385.
Full textAbstract:
Objective: Muscular strength has been shown to inversely associate with mortality. The purpose of this study was to examine the association between muscular strength and residual-specific mortality among a national sample of US adults, which has yet to be investigated. Here, residual-specific mortality is identified as deaths not inclusive of the 9 leading causes of death as identified by the International Classification of Diseases, 10th revision. Methods: Data from the 1999–2002 National Health and Nutrition Examination Survey were used (N = 2171 adults, aged 50–85 y). Participants were followed through 2011, including a median follow-up of 125 months. Lower extremity muscular strength was assessed using maximal isokinetic contractions. Results: After adjusting for all covariates (age, gender, race/ethnicity, body mass index, C-reactive protein, mean arterial pressure, self-report of meeting aerobic-based physical activity guidelines, and physician diagnoses of diabetes), the Cox proportional hazard model demonstrated that for every 25 N increase in lower extremity muscular strength, individuals had a 14% reduced risk of residual-specific death (hazard ratio = 0.86; 95% confidence interval, 0.78–0.96; P = .008). Conclusion: Lower body muscular strength is inversely and independently associated with residual-specific mortality risk, underscoring the importance of adequate muscular strength to prolong survival.
46
Kim, Hyeonmok, Sun Hee Beom, Tae Ho Kim, and Beom-Jun Kim. "Association of Water Intake with Hand Grip Strength in Community-Dwelling Older Adults." Nutrients 13, no. 6 (May 21, 2021): 1756. http://dx.doi.org/10.3390/nu13061756.
Full textAbstract:
Although recent clinical studies have suggested that water intake enhances muscle mass, its impact on muscle strength remain unclear, especially in older adults. This cross-sectional, population-based study using a representative sample of Koreans investigated the relationship of water intake with hand grip strength (HGS) in 4443 older adults, including 2090 men aged ≥50 years and 2253 postmenopausal women. A digital grip strength dynamometer was used for HGS assessment. Low muscle strength was defined by the Korean-specific HGS cut-off value and adequate water intake was defined according to the Korean dietary reference intakes. In an unadjusted model, water intake was significantly higher in men and women without than with low muscle strength (both p < 0.001), but this difference disappeared after adjustment for confounding variables in both men (p = 0.050) and women (p = 0.245). Similarly, the correlation between water intake and HGS, the difference in HGS depending on adequate water intake status, and the risk of low muscle strength depending on water intake quartile were significant only in the unadjusted model. These data indicate that factors such as age, body size, and resistance exercise contribute to improvements in HGS in older adults, whereas water intake may not.
47
Beliaeff, Serge, Danielle R. Bouchard, Christophe Hautier, Martin Brochu, and Isabelle J. Dionne. "Association between Muscle Mass and Isometric Muscle Strength in Well-Functioning Older Men and Women." Journal of Aging and Physical Activity 16, no. 4 (October 2008): 484–93. http://dx.doi.org/10.1123/japa.16.4.484.
Full textAbstract:
This cross-sectional study examined the relationship between arm and leg muscle mass and isometric muscle strength in 465 well-functioning women and 439 well-functioning men from the NuAge cohort, age 67–84 years. Leg and arm muscle mass and body fat were measured by dual-X-ray absorptiometry. Maximum voluntary isometric strength of knee extensors and elbow flexors was measured using the belt-resisted method and a handheld dynamometer, respectively. The regression model including leg muscle mass, physical activity level, age, height, and body fat explained 14% of the variance in quadriceps strength in men and 11% in women (p< .001), whereas the model including arm muscle mass and the same covariates elucidated 40% and 28%, respectively, of the variance in biceps strength (p< .001). These results suggest that muscle mass does not play a crucial role in the variations of isometric muscle strength in well-functioning elderly.
48
Denenberg, Victor H. "Testosterone is non-zero, but what is its strength?" Behavioral and Brain Sciences 21, no. 3 (June 1998): 372. http://dx.doi.org/10.1017/s0140525x98351225.
Full textAbstract:
Mazur & Booth have shown an association between testosterone and dominance behavior, but the strength of the relationship is not given. In addition to being statistically significant, it is also necessary that testosterone account for a meaningful proportion of the variance; a multivariate model is probably necessary. A cautionary tale from the animal literature is related.
49
Curtis, Siân L., and Fiona Steele. "Variations in familial neonatal mortality risks in four countries." Journal of Biosocial Science 28, no. 2 (April 1996): 141–59. http://dx.doi.org/10.1017/s0021932000022203.
Full textAbstract:
SummaryThis paper investigates variations in the strength and structure of familial association in neonatal mortality risks in four populations; Bolivia, Kenya, Peru, and Tanzania. Exploratory analyses of the structure of the familial association are presented for each population. Random effects logistic models are then used to estimate the strength of familial association in neonatal mortality risks using a standard set of control variables. The results suggest that the strength of familial association in neonatal mortality risks is quite similar in these four populations which would be consistent with a biological explanation for the association. However, some differences were found, particularly in the form of the association in Peru, which may suggest at least a small role of other factors.
50
Mahanta, Janardan, Syed Tanjim Hossain, and Imtiaz Reza. "Impact the Temperature of Bangladesh: An Application of Markov Model." Asia Pacific Journal of Energy and Environment 6, no. 2 (December 31, 2019): 83–90. http://dx.doi.org/10.18034/apjee.v6i2.269.
Full textAbstract:
Markov chain model has been used to analyze the temperature of Bangladesh. Different order Markov chain model has constructed and their significance has been tested. Using Cramer’s , strength the association of temperature with the order of Markov chain has been measured. Stationary probability has been calculated, and there have been employed whether the temperature is stationary or not.