scholarly journals Retroactive Interference Model of Forgetting

2019 ◽  
Author(s):  
Antonios Georgiou ◽  
Mikhail Katkov ◽  
Misha Tsodyks
Keyword(s):  
Power Law ◽  
Phenomenological Model ◽  
Retroactive Interference ◽  
Interference Model ◽  
Good Match ◽  
Dimensional Version ◽  
Two Sides

AbstractMemory and forgetting constitute two sides of the same coin, and although the first has been rigorously investigated, the latter is often overlooked. A number of experiments under the realm of psychology and experimental neuroscience have described the properties of forgetting in humans and animals, showing that forgetting exhibits a power-law relationship with time. These results indicate a counter-intuitive property of forgetting, namely that old memories are more stable than younger ones. We have devised a phenomenological model that is based on the principle of retroactive interference, such that stronger memories acquired after weaker ones erase the latter. The model has only one free integer parameter and can be solved analytically. Recognition experiments with long streams of words were performed, resulting in a good match to a five-dimensional version of the model.

scholarly journals Retroactive interference model of forgetting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antonios Georgiou ◽  
Mikhail Katkov ◽  
Misha Tsodyks
Keyword(s):  
Mathematical Model ◽  
Phenomenological Models ◽  
Power Law ◽  
Time Course ◽  
Retroactive Interference ◽  
Interference Model ◽  
Current Contribution ◽  
Theoretical Predictions ◽  
Two Sides

AbstractMemory and forgetting constitute two sides of the same coin, and although the first has been extensively investigated, the latter is often overlooked. A possible approach to better understand forgetting is to develop phenomenological models that implement its putative mechanisms in the most elementary way possible, and then experimentally test the theoretical predictions of these models. One such mechanism proposed in previous studies is retrograde interference, stating that a memory can be erased due to subsequently acquired memories. In the current contribution, we hypothesize that retrograde erasure is controlled by the relevant “importance” measures such that more important memories eliminate less important ones acquired earlier. We show that some versions of the resulting mathematical model are broadly compatible with the previously reported power-law forgetting time course and match well the results of our recognition experiments with long, randomly assembled streams of words.

The two sides of CEO pay injustice

2018 ◽  
Vol 16 (1) ◽  
pp. 3-30 ◽  
Author(s):  
Herman Aguinis ◽  
Geoffrey P. Martin ◽  
Luis R. Gomez-Mejia ◽  
Ernest H. O’Boyle ◽  
Harry Joo
Keyword(s):  
Normal Distribution ◽  
Power Law ◽  
Chief Executive Officers ◽  
Risk Sharing ◽  
Chief Executive ◽  
Return On Assets ◽  
Content Type ◽  
Ceo Pay ◽  
Executive Officers ◽  
Two Sides

Purpose The purpose of this study was to examine the extent to which chief executive officers (CEOs) deserve the pay they receive both in terms of over and underpayment. Design/methodology/approach Rather than using the traditional normal distribution view in which CEO performance clusters around the mean with relatively little variance, the authors adopt a novel power law approach. They studied 22 industries and N = 4,158 CEO-firm combinations for analyses based on Tobin’s Q and N = 5,091 for analyses based on return on assets. Regarding compensation, they measured the CEO distribution based on total compensation and three components of CEO total pay: salary, bonus, and value of options exercised. Findings In total, 86 percent of CEO performance and 91 percent of CEO pay distributions fit a power law better than a normal distribution, indicating that a minority of CEOs are producing top value for their firms (i.e. CEO performance) and a minority of CEOs are appropriating top value for themselves (i.e. CEO pay). But, the authors also found little overlap between CEOs who are the top performers and CEOs who are the top earners. Implications The findings shed new light on CEO pay deservingness by using a novel conceptual and methodological lens that highlights systematic over and underpayment. Results suggest a violation of distributive justice and offer little support for agency theory’s efficient contracting hypothesis, which have important implications for agency theory, equity theory, justice theory, and agent risk sharing and agent risk bearing theories. Practical implications Results highlight erroneous practices when trying to benchmark CEO pay based on average levels of performance in an industry because the typical approach to CEO compensation based on averages significantly underpays stars and overpays average performers. Originality/value Results offer new insights on the extent of over and underpayment. The findings uncover an extremely large non-overlap between the top earning and top performing CEOs and to an extent far greater in magnitude than previously suggested.

scholarly journals Inverse power law potentials about polygonal prisms and in polygonal cavities

1977 ◽  
Vol 20 (2) ◽  
pp. 241-253 ◽  
Author(s):  
J. R. Philip
Keyword(s):  
Power Law ◽  
Inverse Power ◽  
Intermolecular Potential ◽  
Legendre Functions ◽  
Associated Legendre Functions ◽  
Inverse Power Law ◽  
Two Sides

AbstractThe effects on adsorption of the geometry of the solid may be studied through calculations based on a (distance)−ε (ε> 3) intermolecular potential. This paper establishes the result that the potential due to an infinitely long polygonal homogeneous solid prism, at position r in the plane of its right section, is – . Here ρi = ∣ r − ri ∣, where the ri are the position vectors of the n vertices of the polygon, and θij are the angles r − ri makes with the two sides of the polygon which meet at vertex ri. The g's are exact functions of θij. They are, in general, integrals of associated Legendre functions, but they are elementary for ε an even integer. A similar result holds for the potential within an infinitely long polygonal prismatic cavity. The analysis involves a systematic superposition schema and the concept of a supplementary potential with datum within the solid at infinity. The cases ε = 6 and ε = 4 are treated in detail and illustrative solutions given for the following configurations: semi-infinite laminae, deep rectangular cracks, square prisms, square prismatic cavities and regular n-gonal prismatic cavities.

The two sides of CEO pay injustice: a commentary

2018 ◽  
Vol 16 (1) ◽  
pp. 90-96
Author(s):  
Albert Cannella ◽  
Valerie Sy
Keyword(s):  
Power Law ◽  
Design Methodology ◽  
Ceo Compensation ◽  
Power Law Distribution ◽  
Content Type ◽  
Compensation Process ◽  
Ceo Pay ◽  
Two Sides ◽  
Theoretical Issues ◽  
Research Domain

Purpose The purpose of this paper is to extend discussions in the CEO compensation research domain. Specifically, this paper provides a critical analysis of the power law conceptualization and pay injustice contribution by Aguinis, Martin, Gomez-Mejia, O’Boyle and Joo. Design/methodology/approach This commentary addresses statistical and theoretical issues of the power law distribution with respect to prior compensation research and offers additional perspectives on the issue of CEO pay deservingness. Findings The power law is worth investigating further, but more attention should be paid to outliers and fit to the distribution. Stronger theory is needed for using the power law to explain CEO compensation phenomena, especially regarding standard firm performance measures and anomalies in the compensation process. Finally, “injustice” and “deservingness” in discussions of CEO pay exist in the eye of the beholder. Originality/value This paper offers additional considerations for scholars to explore when applying the power law distribution to compensation research.

scholarly journals Prediction of Magnetic Properties of a Plastically Deformed Steel and One Way to Measure its Plastic Deformation

2020 ◽  
Vol 20 (2) ◽  
pp. 5-13
Author(s):  
M.J. Sablik
Keyword(s):  
Plastic Deformation ◽  
Magnetic Properties ◽  
Dislocation Density ◽  
Plastic Strain ◽  
Yield Stress ◽  
Magnetic Materials ◽  
Power Law ◽  
Phenomenological Model ◽  
Magnetic Hysteresis ◽  
Hysteresis Loss

AbstractIn this paper, we use a phenomenological model based on the Jiles-Atherton-Sablik model of stress affecting the magnetic hysteresis of magnetic materials as modified when stress goes past the yield stress We use this to show that (1) the model produces sharp shearing of hysteresis curves, as seen experimentally and that (2) it also produces a step in the hysteresis loss at small residual plastic strain. We also find that the step in the hysteresis loss can be fitted to a power law, and find that the power law can be fitted by the power m=0.270, different from the mechanical Ludwik Law exponent, and reasonably close to the experimental 0.333 and 0.202. We will also suggest a method of measuring how plastically deformed the material is by suggesting how the dislocation density can be measured.

scholarly journals Dependence on the environment of the abundance function of light-cone simulation dark matter haloes

2018 ◽  
Vol 616 ◽  
pp. A137 ◽  
Author(s):  
Maria Chira ◽  
Manolis Plionis ◽  
Pier-Stefano Corasaniti
Keyword(s):  
Dark Matter ◽  
Power Law ◽  
Phenomenological Model ◽  
Light Cone ◽  
Dark Matter Halo ◽  
Nearest Neighbour ◽  
Spherical Region ◽  
Theoretical Mass ◽  
Mass Functions ◽  
Characteristic Mass

Aims. We study the dependence of the halo abundance function (AF) on different environments in a whole-sky ΛCDM light-cone halo catalogue extending to z ~ 0.65, using a simple and well-defined halo isolation criterion. Methods. The isolation status of each individual dark matter halo is determined by the distance to its nearest neighbour, which defines the maximum spherical region devoid of halos above a threshold mass around it (although the true size of such region may be much larger since it is not necessarily spherical). A versatile double power-law Schechter function is used to fit the dark matter halo AF, and its derived parameters are studied as a function of halo isolation status. Results. (a) Our function fits the halo abundances for all halo isolation statuses extremely well, while the well-established theoretical mass functions, integrated over the volume of the light-cone, provide an adequate but poorer fit than our phenomenological model. (b) As expected, and in agreement with other studies based on snap-shot simulations, we find significant differences of the halo abundance function as a function of halo isolation, indicating different rates of halo formation. The slope of the power law and the characteristic mass of the Schechter-like fitting function decrease with isolation, a result consistent with the formation of less massive haloes in lower density regions. (c) We find an unexpected upturn of the characteristic mass of the most isolated haloes of our sample. This upturn originates and characterises only the higher redshift regime (z ≳ 0.45), which probably implies a significant and recent evolution of the isolation status of the most isolated and most massive haloes.

Comments on two sides of CEO pay injustice

2018 ◽  
Vol 16 (1) ◽  
pp. 107-116
Author(s):  
Martin J. Conyon
Keyword(s):  
Executive Compensation ◽  
Power Law ◽  
Boards Of Directors ◽  
Quantitative Methods ◽  
Pay For Performance ◽  
Critical Evaluation ◽  
Estimation Methods ◽  
Content Type ◽  
Ceo Pay ◽  
Two Sides

Purpose This is a short commentary on Herman Aguinis, Geoffrey Martin, Luis Gomez-Mejia, Ernest Boyle and Harry Joo (2017): “Two sides of CEO pay injustice: A power law conceptualization of CEO over and underpayment.” Design/methodology/approach Using insights from prior studies on executive compensation, the author’s commentary presents a critical evaluation of “Two sides of CEO pay injustice: […].” In addition, the author offers potential avenues for further research. Findings The paper “Two sides of CEO pay injustice” is well executed and makes several significant contributions to the management and executive compensation literature. Particularly, noteworthy are the use of advanced quantitative methods, the use of power law distributions to explain chief executive officer (CEO) pay outcomes, the focus on pay-for-performance and the role of justice in CEO outcomes. The author’s commentary in the present paper discusses the measurement of CEO pay and performance, poses alternative estimation methods to explore the pay-for-performance link and offers thoughts on justice theory in the context of CEO pay. Research limitations/implications The authors’ findings may be briefly stated as CEO pay is better described by a power law distribution than a normal distribution, CEO pay is not linked to firm performance and the patterns of CEO pay does not conform to patterns of distributive justice. Overall, the authors provide an important way to evaluate CEO pay outcomes. Thy set the stage for new avenues of research. Practical implications CEO pay is a highly controversial subject in the domain of corporate governance. This paper offers boards of directors and policymakers a method to better understand the success or failure of boardroom pay policies. Social implications CEO pay is an important social measure. Originality/value The authors’ paper is original by offering a method for determining over and underpayment of CEOs. The author in the present paper makes suggestions on how one might extend the research.

scholarly journals The dental anomaly: how and why dental caries and periodontitis are phenomenologically atypical

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Dylan Rakhra
Keyword(s):  
Dental Caries ◽  
Phenomenological Model ◽  
Phenomenological Analysis ◽  
Philosophical Methodology ◽  
Philosophical Method ◽  
Medical Models ◽  
Dental Diseases ◽  
Models Of Disease ◽  
Fitting In ◽  
Two Sides

Abstract Background Despite their shared origins, medicine and dentistry are not always two sides of the same coin. There is a long history in medical philosophy of defining disease and various medical models have come into existence. Hitherto, little philosophical and phenomenological work has been done considering dental caries and periodontitis as examples of disease and illness. Methods A philosophical methodology is employed to explore how we might define dental caries and periodontitis using classical medical models of disease – the naturalistic and normativist. We identify shared threads and highlight how the features of these highly prevalent dental diseases prevent them fitting in either definition. The article describes phenomenology and the current thought around the phenomenology of illness, exploring how and why these dental illnesses might integrate into a phenomenological model. Results We discover that there are some features particular to dental caries and periodontitis: ubiquity, preventability and hyper-monitorablility. Understanding the differences that these dental diseases have compared to many other classically studied diseases leads us to ethical questions concerning how we might manage those who have symptoms and seek treatment. As dental caries and periodontitis are common, preventable and hyper-monitorable, it is suggested that these features affect the phenomenology of these illnesses. For example, if we experience dental illness when we have consciously made decisions that have led to it, do we experience them differently to those rarer illnesses that we cannot expect? Other diseases share these features are discussed. Conclusions This paper highlights the central differences between the classical philosophical notion of disease in medicine and the dental examples of caries and periodontitis. It suggests that a philosophical method of conceptualising medical illness - phenomenology - should not be applied to these dental illnesses without thought. A phenomenological analysis of any dental illness is yet to be done and this paper highlights why a separate strand of phenomenology should be explored, instead of employing those that are extant. The article concludes with suggestions for further research into the nascent field of the phenomenology of dental illness and aims to act as a springboard to expose the dental sphere to this philosophical method of analysis.

PHENOMENOLOGICAL MODEL FOR CREEP BEHAVIOR IN Cu–8.5 at.% Al ALLOY

2007 ◽  
Vol 21 (05) ◽  
pp. 747-753
Author(s):  
M. ABO-ELSOUD
Keyword(s):  
Melting Temperature ◽  
Power Law ◽  
Creep Behavior ◽  
Phenomenological Model ◽  
Intermediate Temperature ◽  
Al Alloy ◽  
Dislocation Glide ◽  
Intermediate Temperature Range ◽  
Controlling Mechanism ◽  
Creep Regime

Creep experiments were conducted on Cu –8.5 at.% Al alloy in the intermediate temperature range, 673–873 K, corresponding to 0.46–0.72 T m , where T m is the absolute melting temperature. The present analysis reveals the presence of two distinct deformation regions (climb and viscous glide) in the plot of log [Formula: see text] versus log σ. The implications of these results on the transition from power-law to exponential creep regime are examined. The results indicated that the rate-controlling mechanism for creep is the obstacle-controlled dislocation glide. A phenomenological model is proposed, which assumes that cell boundaries with sub-grains act as sources and obstacles to gliding dislocations.

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