Justificatory defenses apply to actions that are generally wrong and illegal—mainly since they harm people—when they are justified—usually since they prevent harm to others. A strict conception of justification limits justificatory defenses to actions that reflect all pertinent principles in the optimal manner. A more relaxed conception of justification applies to actions that do not reflect all pertinent principles optimally due to mistake but are not too far from this optimum. In the paper, I consider whether justificatory defenses should (...) reflect the strict conception of justification or a more relaxed conception of justification. This question is important since often the relevant actions are not strictly justified, while the alternative of an excuse is frequently irrelevant or does not provide an appropriate solution. Reflection on this question raises the following dilemma: On the one hand, the strict interpretation seems too harsh, especially with regard to legal liability. On the other hand, it is difficult to explain the basis for a more relaxed conception of justification. I conclude, first, that justification—and accordingly wrongfulness—is a matter of degree and that the strictly justified action is merely the peak of a continuum, and, second, that a practical reaction is in place only with regard to actions whose wrongness is above a minimal threshold. (shrink)

Journals regulate a significant portion of the communication between scientists. This paper devises an agent-based model of scientific practice and uses it to compare various strategies for selecting publications by journals. Surprisingly, it appears that the best selection method for journals is to publish relatively few papers and to select those papers it publishes at random from the available “above threshold” papers it receives. This strategy is most effective at maintaining an appropriate type of diversity that is needed to (...) solve a particular type of scientific problem. This problem and the limitation of the model is discussed in detail. (shrink)

We consider human performance on an optimal stopping problem where people are presented with a list of numbers independently chosen from a uniform distribution. People are told how many numbers are in the list, and how they were chosen. People are then shown the numbers one at a time, and are instructed to choose the maximum, subject to the constraint that they must choose a number at the time it is presented, and any choice below the maximum is incorrect. (...) We present empirical evidence that suggests people use threshold-based models to make decisions, choosing the first currently maximal number that exceeds a fixed threshold for that position in the list. We then develop a hierarchical generative account of this model family, and use Bayesian methods to learn about the parameters of the generative process, making inferences about the threshold decision models people use. We discuss the interesting aspects of human performance on the task, including the lack of learning, and the presence of large individual differences, and consider the possibility of extending the modeling framework to account for individual differences. We also use the modeling results to discuss the merits of hierarchical, generative and Bayesian models of cognitive processes more generally. (shrink)

How, and how well, do people switch between exploration and exploitation to search for and accumulate resources? We study the decision processes underlying such exploration/exploitation trade‐offs using a novel card selection task that captures the common situation of searching among multiple resources (e.g., jobs) that can be exploited without depleting. With experience, participants learn to switch appropriately between exploration and exploitation and approach optimal performance. We model participants' behavior on this task with random, threshold, and sampling strategies, and (...) find that a linear decreasing threshold rule best fits participants' results. Further evidence that participants use decreasing threshold‐based strategies comes from reaction time differences between exploration and exploitation; however, participants themselves report non‐decreasing thresholds. Decreasing threshold strategies that “front‐load” exploration and switch quickly to exploitation are particularly effective in resource accumulation tasks, in contrast to optimal stopping problems like the Secretary Problem requiring longer exploration. (shrink)

Phenomena like meat sharing in hunter-gatherers, altruistic self-sacrifice in intergroup conflicts, and contribution to the production of public goods in laboratory experiments have led to the development of numerous theories trying to explain human prosocial preferences and behavior. Many of these focus on direct and indirect reciprocity, assortment, or (cultural) group selection. Here, I investigate analytically how genetic relatedness changes the incentive structure of that paradigmatic game which is conventionally used to model and experimentally investigate collective action problems: the public (...) goods game. Using data on contemporary hunter-gatherer societies I then estimate a threshold value determining when biological altruism turns into maximizing inclusive fitness in this game. I find that, on average, contributing no less than about 40% of individual fitness to public goods production still is an optimal strategy from an inclusive fitness perspective under plausible socio-ecological conditions. (shrink)

We provide an economic interpretation of the practice consisting in incorporating risk measures as constraints in an expected prospect maximization problem. For what we call the infimum of expectations class of risk measures, we show that if the decision maker (DM) maximizes the expectation of a random prospect under constraint that the risk measure is bounded above, he then behaves as a “generalized expected utility maximizer” in the following sense. The DM exhibits ambiguity with respect to a family of utility (...) functions defined on a larger set of decisions than the original one; he adopts pessimism and performs first a minimization of expected utility over this family, then performs a maximization over a new decisions set. This economic behaviour is called “maxmin under risk” and studied by Maccheroni (Econ Theory 19:823–831, 2002). As an application, we make the link between an expected prospect maximization problem, subject to conditional value-at-risk being less than a threshold value, and a non-expected utility economic formulation involving “loss aversion”-type utility functions. (shrink)

I resolve a previously unnoticed anomaly in the analysis of collective action problems. Some political theorists apply game theory to analyze the paradox of anarchy: War is apparently inevitable in anarchy even though all warring parties prefer peace over war. Others apply tipping threshold analysis to resolve the paradox of revolution: Joining a revolution is apparently always irrational even when an overwhelming majority of the population wish to replace their regime. The usual game theoretic analysis of anarchy yields the (...) conclusion that the suboptimal equilibrium of war is inevitable. The usual tipping threshold analysis of revolution yields the conclusion that the optimal equilibrium of successful revolution is possible. Yet structurally the collective action problems of anarchy and potential revolution are much the same. This suggests that tipping threshold analysis and game theory are incompatible methodologies, despite their widespread use in the social sciences. I argue that there is no real tension between game theory and tipping threshold analysis, even though these methodologies have developed largely independently of each other. I propose a Variable Belief Threshold model of collective action that combines elements of game theory and tipping threshold analysis. I show by example that one can use this kind of hybrid model to give compatible explanations of conflict in anarchy and successful revolution.1. Introduction2. Two Classic Problems, and Two Popular Analyses2.1. The paradox of anarchy2.2. The paradox of revolution3. Restating the Puzzle4. Evaluating the Prisoners’ Dilemma and S-Curve Models5. The Variable Belief Threshold ModelExample 5.1. A population of moderates with independent deviationsExample 5.2 A heterogeneous population with independent deviationsExample 5.3 A heterogeneous population with coordinated deviations6. ConclusionAppendix: Computer Simulations. (shrink)

With the aging of the general population and the ability of intensivists to support patients using ventilator support, tracheostomy has become a vital tool in the medical management of critically ill patients. While much of the medical literature on tracheostomy has focused on the optimal timing of and indications for performing this procedure, little is written on the ethical tensions that can revolve around decisions by patients, surrogates, and physicians on its use. This article will elucidate the ethical dilemmas (...) that can arise surrounding the use of tracheostomy in critically ill patients and how ethics consultants and committees can approach these cases to allow resolution. (shrink)

The role of antibody-antigen affinity and concentrations in adaptive antibody response is analyzed in a framework of probabilistic inventory model for antibody production. Our results indicate significant differences in optimal behaviours of low, moderate and high affinity groups and offer important implications. Interestingly, the involved approach is also of relevance in other production systems. Directions for its applications in industries and information sciences are also presented.

In this paper, the most common pepper noise in grayscale image noise is investigated in depth in the median filtering algorithm, and the improved median filtering algorithm, adaptive switching median filtering algorithm, and adaptive polar median filtering algorithm are applied to the OTSU algorithm. Two improved OTSU algorithms such as the adaptive switched median filter-based OTSU algorithm and the polar adaptive median filter-based OTSU algorithm are obtained. The experimental results show that the algorithm can better cope with grayscale images contaminated (...) by pretzel noise, and the segmented grayscale images are not only clear but also can better retain the detailed features of grayscale images. A genetic algorithm is a kind of search algorithm with high adaptive, fast operation speed, and good global space finding ability, and it will have a good effect when applied to the threshold finding of the OTSU algorithm. However, the traditional genetic algorithm will fall into the local optimal solution in different degrees when finding the optimal threshold. The advantages of the two interpolation methods proposed in this paper are that one is the edge grayscale image interpolation algorithm using OTSU threshold adaptive segmentation and the other is the edge grayscale image interpolation algorithm using local adaptive threshold segmentation, which can accurately divide the grayscale image region according to the characteristics of different grayscale images and effectively improve the loss of grayscale image edge detail information and jagged blur caused by the classical interpolation algorithm. The visual effect of grayscale images is enhanced by selecting grayscale images from the standard grayscale image test set and interpolating them with bilinear interpolation, bucolic interpolation, NEDI interpolation, and FEOI interpolation for interpolation simulation validation. The subjective evaluation and objective evaluation, as well as the running time, are compared, respectively, showing that the method of this paper can effectively improve the quality of grayscale image interpolation. (shrink)

Setting optimal significance levels that minimize Type I and Type II errors allows for more transparent and well‐considered statistical decision making compared to the traditional α = 0.05 significance level. We use the optimal α approach to re‐assess conclusions reached by three recently published tests of the pace‐of‐life syndrome hypothesis, which attempts to unify occurrences of different physiological, behavioral, and life history characteristics under one theory, over different scales of biological organization. While some of the conclusions reached using (...) optimal α were consistent to those previously reported using the traditional α = 0.05 threshold, opposing conclusions were also frequently reached. The optimal α approach reduced probabilities of Type I and Type II errors, and ensured statistical significance was associated with biological relevance. Biologists should seriously consider their choice of α when conducting null hypothesis significance tests, as there are serious disadvantages with consistent reliance on the traditional but arbitrary α = 0.05 significance level. (shrink)

Paper attempts to empiricaly verify a non-linear (parabolic) dependence of employment in Poland on minimum wage to average wage ratio (Kaitz coefficient). The aim of the analysis is to find the optimal value of the Kaitz coefficient. The obtained result confirms the hypothesis on a non-linear nature of the investigated dependence. However, during the minimum wage evaluation process it is worth noting that the Kaitz coefficient's influence on the employment is bi-directional. Increase in the Kaitz coefficient value will only (...) have a negative effect on employment after a certain threshold is crossed. Results pre-sented in the paper allow to identify such a critical value and to establish the coefficient value intervals with negative and positive influence on employment. (shrink)

We propose a formal framework for interpretable machine learning. Combining elements from statistical learning, causal interventionism, and decision theory, we design an idealised explanation game in which players collaborate to find the best explanation for a given algorithmic prediction. Through an iterative procedure of questions and answers, the players establish a three-dimensional Pareto frontier that describes the optimal trade-offs between explanatory accuracy, simplicity, and relevance. Multiple rounds are played at different levels of abstraction, allowing the players to explore overlapping (...) causal patterns of variable granularity and scope. We characterise the conditions under which such a game is almost surely guaranteed to converge on a optimal explanation surface in polynomial time, and highlight obstacles that will tend to prevent the players from advancing beyond certain explanatory thresholds. The game serves a descriptive and a normative function, establishing a conceptual space in which to analyse and compare existing proposals, as well as design new and improved solutions. (shrink)

Epistemologists can be divided into two camps: those who think that nothing short of certainty or (subjective) probability 1 can warrant assertion and those who disagree with this claim. This paper addressed this issue by inquiring into the problem of setting the probability threshold required for assertion in such a way that that the social epistemic good is maximized, where the latter is taken to be the veritistic value in the sense of Goldman (Knowledge in a social world, 1999). (...) We provide a Bayesian model of a test case involving a community of inquirers in a social network engaged in group deliberation regarding the truth or falsity of a proposition $p.$ p . Results obtained by means of computer simulation indicate that the certainty rule is optimal in the limit of inquiry and communication but that a lower threshold is preferable in less idealized cases. (shrink)

Although logical consistency is desirable in scientific research, standard statistical hypothesis tests are typically logically inconsistent. To address this issue, previous work introduced agnostic hypothesis tests and proved that they can be logically consistent while retaining statistical optimality properties. This article characterizes the credal modalities in agnostic hypothesis tests and uses the hexagon of oppositions to explain the logical relations between these modalities. Geometric solids that are composed of hexagons of oppositions illustrate the conditions for these modalities to be logically (...) consistent. Prisms composed of hexagons of oppositions show how the credal modalities obtained from two agnostic tests vary according to their threshold values. Nested hexagons of oppositions summarize logical relations between the credal modalities in these tests and prove new relations. (shrink)

We present a dynamic programming model which is used to investigate hypothermia as an adaptive response by small passerine birds in winter. The model predicts that there is a threshold function of reserves during the night, below which it is optimal to enter hypothermia, and above which it is optimal to rest. This threshold function decreases during the night, with a particularly sharp drop at the end of the night, representing the time and energy costs associated (...) with returning to normal body temperature. The results of the model emphasise the trade-off between energy and predation, not just between foraging options, but also between foraging during the day and entering hypothermia at night. The value of being able to use hypothermia represents not just energy savings, but also reduced predation risk due to changes in the optimal foraging strategy. Conditions which give a high value of hypothermia are short photoperiod, variable food supply, low temperatures, poor and scarce food supplies. (shrink)

In literature, the firm’s selection of dual-product strategy under cap-and-trade regulation and the optimal emission reduction decisions are not well studied, especially through an analytical approach. We develop a theoretic model to investigate the firm’s selection on three product strategies in the presence of cap-and-trade policy, including two single product strategies and a dual-product strategy, and identify two types of consumers: consumers with low-carbon preference and regular consumers. Our analysis shows that, in the absence of cap-and-trade policy, it is (...) optimal to adopt dual-product strategy, but in the presence of this policy, it is optimal to adopt dual-product strategy or low-carbon product strategy. Compared with ordinary product strategy, adopting a low-carbon product strategy or dual-product strategy benefits the firm under cap-and-trade regulation. The additional cost of producing low-carbon product has an impact on the firm’s product strategy selection under cap-and-trade regulation. When it falls below a certain threshold, it is optimal to adopt a dual-product strategy; otherwise, it is optimal to adopt a low-carbon product strategy. Our research can provide reference for firm’s decision-making and government’s policy formulation. (shrink)

Developmental models that account for the metabolic effect of temperature variability on poikilotherms, such as degree-day models, have been widely used to study organism emergence, range and development, particularly in agricultural and vector-borne disease contexts. Though simple and easy to use, structural and parametric issues can influence the outputs of such models, often substantially. Because the underlying assumptions and limitations of these models have rarely been considered, this paper reviews the structural, parametric, and experimental issues that arise when using degree-day (...) models, including the implications of particular structural or parametric choices, as well as assumptions that underlie commonly used models. Linear and non-linear developmental functions are compared, as are common methods used to incorporate temperature thresholds and calculate daily degree-days. Substantial differences in predicted emergence time arose when using linear versus non-linear developmental functions to model the emergence time in a model organism. The optimal method for calculating degree-days depends upon where key temperature threshold parameters fall relative to the daily minimum and maximum temperatures, as well as the shape of the daily temperature curve. No method is shown to be universally superior, though one commonly used method, the daily average method, consistently provides accurate results. The sensitivity of model projections to these methodological issues highlights the need to make structural and parametric selections based on a careful consideration of the specific biological response of the organism under study, and the specific temperature conditions of the geographic regions of interest. When degree-day model limitations are considered and model assumptions met, the models can be a powerful tool for studying temperature-dependent development. (shrink)

We study the performance of heuristics relative to the performance of optimal solutions in the rich domain of sequential search, where the decision to stop the search depends only on the applicant’s relative rank. Considering multiple variants of the secretary problem, that vary from one another in their formulation and method of solution, we find that descriptive heuristics perform well only when the optimal solution prescribes a single threshold value. We show that a computational heuristic originally proposed (...) as an approximate solution to a single variant of the secretary problem performs equally well in many other variants where the optimal solution prescribes multiple threshold values that gradually relax the criterion for stopping the search. Finally, we propose a new heuristic with near optimal performance in a competitive or strategic variant of the secretary problem with multiple employers competing with one another to hire job applicants. Both heuristics share a simple computational component: the ratio of the number of interviewed applicants to the number of those remaining to be searched. We present the subgame-perfect Nash equilibrium for this competitive variant and an algorithm for its computation. (shrink)

Critical-care decision making is highly complex, given the need for health care providers and organizations to consider, and constructively respond to, the diverse interests and perspectives of a variety of legitimate stakeholders. Insights derived from an identified set of ethics-related considerations have the potential to meaningfully inform inclusive and deliberative policy development that aims to optimally balance the competing obligations that arise in this challenging, clinical decision-making domain. A potential, constructive outcome of such policy engagement is the collaborative development of (...) an as-fair-as-possible dispute resolution process that incorporates an appropriated-justified, defensible critical-care obligation threshold. (shrink)

In this paper, an in-depth study of interactive visual communication of network topology through non-line-of-sight congestion control algorithms is conducted to address the real-time routing problem of adapting to dynamic topologies, and a delay-constrained stochastic routing algorithm is proposed to enable packets to reach GB within the delay threshold in the absence of end-to-end delay information while improving network throughput and reducing network resource consumption. The algorithm requires each sending node to select an available relay set based on the (...) location of its neighbor nodes and channel state and computes transfer probabilities for each node in the relay set combining the remaining delay of the packet with the distance from the relay node to GB. Based on the obtained transfer probability and local channel state, the sending node passes the packet to the relay node. The convergence of the algorithm is proved and its performance is verified by simulation. The first part of the algorithm is based on the greedy algorithm to deploy and locate the network flying platform nodes with the goal of efficient coverage of the network flying platform nodes, considering the ground base station services. As the delay on each link varies due to the change of channel state, the source and relay nodes asynchronously update the data generation rate and the pairwise parameters based on the received local information and use the obtained optimal values to pass the packets to GB. (shrink)

According to the standard Humean account of laws of nature, laws are selected partly as a result of an optimal trade-off between the scientific virtues of simplicity and strength. Roberts and Woodward have recently objected that such trade-offs play no role in how laws are chosen in science. In this paper, we first discuss an example from the field of automated scientific discovery which provides concrete support for Roberts and Woodward’s point that scientific theories are chosen based on a (...) single-virtue threshold. However, we then use this very same example as a starting point to argue that i) by insisting on a single best theory, Humeans rely on an overly simplistic conception of trade-offs, that ii) this conception should give way to one which allows for a Pareto front of equally optimal theories, and iii) that given this new conception, threshold behaviour for a virtue like strength is a) compatible with the existence of a genuine trade-off and b) can even play the positive role of a selection criterion. (shrink)

Critical-care decision making is highly complex, given the need for health care providers and organizations to consider, and constructively respond to, the diverse interests and perspectives of a variety of legitimate stakeholders. Insights derived from an identified set of ethics-related considerations have the potential to meaningfully inform inclusive and deliberative policy development that aims to optimally balance the competing obligations that arise in this challenging, clinical decision-making domain. A potential, constructive outcome of such policy engagement is the collaborative development of (...) an as-fair-as-possible dispute resolution process that incorporates an appropriated-justified, defensible critical-care obligation threshold. (shrink)

Attention and adaptation are both mechanisms that optimize visual performance. Attention optimizes performance by increasing contrast sensitivity for and neural response to attended stimuli while decreasing them for unattended stimuli; adaptation optimizes performance by increasing contrast sensitivity for and neural response to changing stimuli while decreasing them for unchanging stimuli. We investigated whether and how the adaptation state and the attentional effect on contrast sensitivity interact. We measured contrast sensitivity with an orientation-discrimination task, in two adaptation conditions—adapt to 0% or (...) 100% contrast—in focused, distributed, and withdrawn attentional conditions. We used threshold and asymptotic performance to index the magnitude of the attentional effect—enhancement or impairment in contrast sensitivity—before and after adapting to high-contrast stimuli. The results show that attention and adaptation affect the contrast psychometric function in a similar but opposite way: Attention increases stimulus salience, whereas adaptation reduces stimulus salience. An interesting finding is that the adaptation state does not modulate the magnitude of the attentional effect. This suggests that attention affects the normalized signal once the effect of contrast adaptation has taken place and that these two mechanisms act separately to change contrast sensitivity. Attention can overcome adaptation to restore contrast sensitivity. (shrink)

Participants struck 500 golf balls to a concealed target. Outcome feedback was presented at the subjective or objective threshold of awareness of each participant or at a supraliminal threshold. Participants who received fully perceptible feedback learned to strike the ball onto the target, as did participants who received feedback that was only marginally perceptible . Participants who received feedback that was not perceptible showed no learning. Upon transfer to a condition in which the target was unconcealed, performance increased (...) in both the subjective and the objective threshold condition, but decreased in the supraliminal condition. In all three conditions, participants reported minimal declarative knowledge of their movements, suggesting that deliberate hypothesis testing about how best to move in order to perform the motor task successfully was disrupted by the impoverished disposition of the visual outcome feedback. It was concluded that sub-optimally perceptible visual feedback evokes implicit processes. (shrink)

According to the sufficiency principle, distributive justice requires that everyone have some sufficient level of resources or well-being, but inequalities above this threshold have no moral significance. This paper defends a version of the sufficiency principle as the appropriate response to moral uncertainty about distributive justice. Assuming that the appropriate response to moral uncertainty is to maximize expected choiceworthiness, and given a reasonable distribution of credence in some familiar views about distributive justice, a version of the sufficiency principle strikes (...) the optimal balance between the competing moral risks posed by implementing these views. In particular, it avoids the moral risk posed by views like Nozick’s libertarianism, which forbid redistributive taxation even for the sake of helping to provide for people’s basic needs: failing to do the latter, if it turns out that justice does require it, would be very morally wrong. This “uncertainty argument” has the advantage of minimizing reliance on controversial intuitions about distributive justice, helps to specifying a non-arbitrary threshold for sufficiency, and shows that the substantive moral implications of moral uncertainty are not limited to high-stakes applied ethics issues such as abortion and vegetarianism but instead extend to an issue at the heart of political philosophy. (shrink)

During each school semester, students face an onslaught of material to be learned. Students work hard to achieve initial mastery of the material, but when they move on, the newly learned facts, concepts, and skills degrade in memory. Although both students and educators appreciate that review can help stabilize learning, time constraints result in a trade-off between acquiring new knowledge and preserving old knowledge. To use time efficiently, when should review take place? Experimental studies have shown benefits to long-term retention (...) with spaced study, but little practical advice is available to students and educators about the optimal spacing of study. The dearth of advice is due to the challenge of conducting experimental studies of learning in educational settings, especially where material is introduced in blocks over the time frame of a semester. In this study, we turn to two established models of memory—ACT-R and MCM—to conduct simulation studies exploring the impact of study schedule on long-term retention. Based on the premise of a fixed time each week to review, converging evidence from the two models suggests that an optimal review schedule obtains significant benefits over haphazard (suboptimal) review schedules. Furthermore, we identify two scheduling heuristics that obtain near optimal review performance: (a) review the material from μ-weeks back, and (b) review material whose predicted memory strength is closest to a particular threshold. The former has implications for classroom instruction and the latter for the design of digital tutors. (shrink)

This paper mainly analyzes the theories related to the financial risk of the company and combines the principles of principal component analysis, particle swarm optimization algorithm, and artificial neural network to derive the financial risk index system of the company. To improve the accuracy of financial risk prediction, principal component analysis and particle swarm algorithm are applied to optimize the BP neural network model, the input data of the prediction model is improved, and the optimal initial weights and thresholds (...) are given to the BP neural network by using particle swarm algorithm search, whereby the financial risk prediction model of particle swarm optimization BP neural network is constructed. The empirical results show that the model constructed by BP neural network not only has a high accuracy rate for static financial risk evaluation but also has a better prediction effect. After training and testing, the BP neural network-based enterprise financial risk evaluation model can accurately determine the existing financial situation of enterprise financial management and has a good prediction effect. Our research method is a fusion of the processing of the two methods, which belongs to the first integration of results. (shrink)

The early warning of financial risk is to identify and analyze existing financial risk factors, determine the possibility and severity of occurring risks, and provide scientific basis for risk prevention and management. The fragility of financial system and the destructiveness of financial crisis make it extremely important to build a good financial risk early-warning mechanism. The main idea of the K-means clustering algorithm is to gradually optimize clustering results and constantly redistribute target dataset to each clustering center to obtain (...) class='Hi'>optimal solution; its biggest advantage lies in its simplicity, speed, and objectivity, being widely used in many research fields such as data processing, image recognition, market analysis, and risk evaluation. On the basis of summarizing and analyzing previous research works, this paper expounded the current research status and significance of financial risk early-warning, elaborated the development background, current status and future challenges of the K-means clustering algorithm, introduced the related works of similarity measure and item clustering, proposed a financial risk indicator system based on the K-means clustering algorithm, performed indicator selection and data processing, constructed a financial risk early-warning model based on the K-means clustering algorithm, conducted the classification of financial risk types and optimization of financial risk control, and finally carried out an empirical experiments and its result analysis. The study results show that the K-means clustering method can effectively avoid the subjective negative impact caused by artificial division thresholds, continuously optimize the prediction process of financial risk and redistribute target dataset to each cluster center for obtaining optimized solution, so the algorithm can more accurately and objectively distinguish the state interval of different financial risks, determine risk occurrence possibility and its severity, and provide a scientific basis for risk prevention and management. The study results of this paper provide a reference for further researches on financial risk early-warning based on K-means clustering algorithm. (shrink)

Experimental evidence strongly supports the view that the subdivision of organ anlagen into smaller structural units is an autonomous process. Dalcq &Pasteels' hypothesis which says that the boundaries between the different areas into which a morphogenetic field differentiates are determined by “Threshold values” in the “potential” of the field in question, is inconsistent with our present knowledge of biochemical reaction systems. Threshold values may only be used indescribing the spatial differentiation of a morphogenetic field. It is suggested that (...) the latter concept be replaced by the concept of “optimal values” in the intensity of a morphogenetic field-specific for the various chemo-differentiations characterizing the different regions into which a morphogenetic field will split up-and that each optimal value isdeterminative for the appearance of one particular differentiation within the morphogenetic field, each differentiation being formed within a certain range of intensity of the field. On the basis of the hypothesis formulated above a “virginal” morphogenetic field will necessarily differentiate into a number of smaller fields of second order, which in their turn will split up into fields of third order, etc. ” Pattern formation” may be defined as the differentiation of a morphogenetic field into an increasing number of smaller fields of higher order of qualitative different chemical and structural composition. Since differentiation of a morphogenetic field proceeds autonomously, the capacity for pattern formation is an intrinsic property of a morphogenetic field. In the light of these considerations it is suggested that a morphogenetic field action is responsible for the first differentiation of the developing embryo into regions with predominantly ectodermal, mesodermal or endodermal differentiation tendencies. The present knowledge about the characteristic pattern formation taking place in the axial mesoderm as well as in the overlying neural plate seems to be in good agreement with the implications of the present morphogenetic field concept. It is emphasized, however, that if the present morphogenetic field concept cannot be characterized further biochemically and biophysically, it will have to be replaced by another concept which can be defined more sharply and is more easily accessible to experimental analysis. Les preuves expérimentales confirment que la subdivision des ébauches des organes en unités structurelles plus petites est un processus autonome. L'hypothèse deDalcq &Pasteels disant que les bornes entre les différents domaines formées par la différenciation d'un champ morphogénétique sont déterminées par des „valeurs seuil” dans le „potentiel” du champ en question, n'est pas en harmonie avec notre connaissance actuelle des systèmes biochimiques. Des “valeurs seuil” ne peuvent être employés qu'en décrivant la différenciation spatiale d'un champ morphogénétique. On prend en considération de remplacer le concept des “valeurs seuil” par le concept des “valeurs optimales” dans l'intensité d'un champ morphogénétique. Ce seraient les valeurs spécifiques aux différenciations chimiques diverses qui caractérisent les différents domaines dans lesquels un champ morphogénétique se différencie. En outre, chaque valeur optimale serait déterminative à la formation d'une différenciation spéciale dans le champ morphogénétique, chaque différentiation se formant dans un certain trajet de l'intensité du champ. Par suite de l'hypothèse formulée ci-dessus un champ morphogénétique “virginal” va nécessairement se différencier en un nombre de champs plus petits de deuxième ordre, qui à leur tour se divisent en champs d'ordre troisième, etc. ... La régionalisation peut être définie comme la différenciation d'un champ morphogénétique dans un nombre de plus en plus élevé de champs plus petits d'ordre supérieur de composition chimique et structurelle qualitativement différente. Parce que la différenciation d'un champ morphogénétique se produit de façon autonome, le pouvoir de régionalisation est une propriété intrinsique d'un champ morphogénétique. Ces considérations nous mènent à proposer que l'action d'un champ morphogénétique est responsable de la première différenciation de l'embryon en régions qui possèdent des tendences de différenciation principalement ectodermiques, mésodermiques, ou bien endodermiques. La connaissance actuelle concernant la régionalisation caractéristique qui se produit dans le mésoderme axial ainsi que dans la plaque neurale superposée paraît se conformer aux conséquences du concept de champ morphogénétique. Cependant on souligne le fait que dans le cas òu le concept actuel du champ morphogénétique ne pourra pas être plus amplement caractérisé de façon biochimique et biophysique, il faudra le remplacer par un autre concept qui puit être défini plus nettement et qui est mieux accessible à l'analyse expérimentale. Die Auffassung, dass die Aufteilung von Organanlagen in kleineren Struktureinheiten ein selbständiger Prozess ist, findet Bestätigung in den experimentellen Ergebnissen. Die Hypothese vonDalcq &Pasteels , dass die Grenzen zwischen den unterschiedenen Gebieten, in denen ein morphogenetisches Feld sich differenziert, durch “Schwellenwerte” im “Potential” des genannten Feldes bestimmt werden, ist unvereinbar mit unserem heutigen Wissen über biochemischen Reaktionssystemen. Der Gebrauch des Begriffs “Schwellenwert” ist nur gestattet bei der Beschreibung der räumlichen Differenzierung eines morphogenetischen Feldes. Statt dieses Begriffs wird der Begriff “Optimaler Wert” vorgeschlagen; Werte also in der Intensität eines morphogenetischen Feldes, optimal und spezifisch für die verschiedene Chemodifferenzierungen, welche die Gebiete kennzeichnen, in denen ein morphogenetisches Feld sich differenzieren wird. Jeder optimaler Wert soll dann das Erscheinen einer bestimmten Differenzierung innerhalb des morphogenetischen Feldes veranlassen, welche Differenzierung sich bildet innerhalb eines bestimmten Bereichs der Feldintensität. Auf Grund der obigen Hypothese wird ein “virginelles” morphogenetisches Feld zwangsläufig sich differenzieren in eine Anzahl kleinerer Feldern zweiten Grades; diese in Felder dritten Grades, usw. Musterbildung könnte definiert werden als die Differenzierung eines morphogenetischen Feldes in eine zunehmende Anzahl kleinerer Felder höheren Grades von qualitativ verschiedener chemischen und strukturellen Zusammensetzung, Weil diese Differenzierung autonom vor sich geht, ist das Vermögen zur Musterbildung eine innewohnende Eigenschaft eines morphogenetischen Feldes. Im Lichte dieser Betrachtungen ist es naheliegend anzunehmen dass eine morphogenetische Feldwirkung verantwortlich ist für die erste Differenzierung des sich entwickelnden Embryos in Gebiete überwiegend ektodermalen, mesodermalen oder entodermalen Differenzierungstendenzen. Die heutigen Kenntnisse über die charakteristische Musterbildung im axialen Teil des Mesoderms und in der überliegenden Neuralplatte scheinen in guter Übereinstimmung zu sein mit den des morphogenetischen Feldbegriffs. Dennoch wird benachdruckt, dass, falls das gegenwärtige morphogenetische Feldbegriff nicht weiter biochemisch und biophysisch gekennzeichnet werden kann, anstatt dessen ein anderer Begriff entwickelt werden muß, der schärfer definiert werden kann und besser zugänglich ist für experimentelle Analyse. (shrink)

McEntire (1984) proved that, for a portfolio problem with independent assets, the generalized harmonic mean plays the role of a risk-free threshold. Based upon this property, he developed a criterion for including or excluding assets in an optimal portfolio, and he proved an ordering theorem showing that an optimal portfolio always consists of positive amounts of the assets with the largest mean values. Also, some commonly used utility functions were shown to satisfy the property that the dominance (...) of an asset over another is unaffected by the addition of other assets. In this paper we extend these results to the case where assets are dependent. (shrink)

The extended dual-aspect monism framework of consciousness, based on neuroscience, consists of five components: (1) dual-aspect primal entities; (2) neural-Darwinism: co-evolution and co-development of subjective experiences (SEs) and associated neural-nets from the mental aspect (that carries the SEs/proto-experiences (PEs) in superposed and unexpressed form) and the material aspect (mass, charge, spin and space-time) of fundamental entities (elementary particles), respectively and co-tuning via sensorimotor interaction; (3) matching and selection processes: interaction of two modes, namely, (a) the non-tilde mode that is the (...) material and mental aspect of cognition (memory and attention) related feedback signals in a neural-network, which is the cognitive nearest past approaching towards present; and (b) the tilde mode that is the material and mental aspect of the feed forward signals due to external environmental input and internal endogenous input, which is the nearest future approaching towards present and is a entropy-reversed representation of non-tilde mode; (4) the segregation and integration of information, and (5) the necessary ingredients of SEs (such as wakefulness, attention, re-entry, working memory, stimulus at or above threshold level, and neural-net PEs). This framework leads to structural and functional coherence between the mind and the brain, bridges the explanatory gap (the gap between SEs and their neural-correlates), and leads to our mundane subjective experiences. This extended dual-aspect monism (eDAM) framework (Vimal, 2008, 2010, 2013, 2015a, 2015b) could be the fundamental basis of various religions and philosophies. This is a Western perspective. On the other hand, Eastern perspectives emphasize the practical methods for achieving altered experience at samadhi state. An important corollary of these methods (such as yogic method) is the sublimation of negative aspects of seven groups of self-protective energy system (desire, anger, ego, greed, attachment, jealousy, and selfish-love) into their positive aspects. Their negative aspects create war and suffering, whereas their positive aspects advance science and technology, family values, peace, and happiness. Here, the Western perspective framework is extended to include the concepts of the sublimation process to encompass Eastern perspectives. The four elements (war, suffering, peace, and happiness) are ubiquitous in both space and time because they are essential contributors to the variations for natural selection in our evolutionary system. The sublimation process optimizes the system: minimizes war and suffering, maximizes peace and happiness, and enhances family values and individual progress. This is consistent with both Eastern and Western perspectives. (shrink)

Piéron's Law describes the relationship between stimulus intensity and reaction time. Previously (Stafford & Gurney, 2004), we have shown that Piéron's Law is a necessary consequence of rise-to-threshold decision making and thus will arise from optimal simple decision-making algorithms (e.g., Bogacz, Brown, Moehlis, Holmes, & Cohen, 2006). Here, we manipulate the color saturation of a Stroop stimulus. Our results show that Piéron's Law holds for color intensity and color-naming reaction time, extending the domain of this law, in line (...) with our suggestion of the generality of the processes that can give rise to Piéron's Law. In addition, we find that Stroop condition does not interact with the effect of color saturation; Stroop interference and facilitation remain constant at all levels of color saturation. An analysis demonstrates that this result cannot be accounted for by single-stage decision-making algorithms which combine all the evidence pertaining to a decision into a common metric. This shows that human decision making is not information-optimal and suggests that the generalization of current models of simple perceptual decision making to more complex decisions is not straightforward. (shrink)

Humans regularly pursue activities characterized by dramatic success or failure outcomes where, critically, the chances of success depend on the time invested working toward it. How should people allocate time between suchmake‐or‐breakchallenges and safe alternatives, where rewards are more predictable (e.g., linear) functions of performance? We present a formal framework for studying time allocation between these two types of activities, and we explore optimal behavior in both one‐shot and dynamic versions of the problem. In the one‐shot version, we illustrate (...) striking discontinuities in the optimal time allocation policy as we gradually change the parameters of the decision‐making problem. In the dynamic version, we formulate the optimal strategy—defined by agiving‐upthreshold—which adaptively dictates when people should stop pursuing the make‐or‐break goal. We then show that this strategy is computationally inaccessible for humans, and we explore boundedly rational alternatives. We compare the performance of the optimal model against (a) a myopic giving‐up threshold that is easier to compute, and even simpler heuristic strategies that either (b) only decide whether or not to start pursuing the goal and never give up or (c) consider giving up at a fixed number of control points. Comparing strategies across environments, we investigate the cost and behavioral implications of sidestepping the computational burden of full rationality. (shrink)

This chapter presents two models of priming. The primary task under consideration is the identification of words presented visually at threshold. The first model, REMI, is a model for long-term priming in implicit memory. It explains repetition priming effects by assuming that during study of a word some contextual information is added to the corresponding lexical trace. This contextual information stored during the study task will tend to match the contextual information present during the test task, leading subjects to (...) prefer studied words over non-studied words. The second model, ROUSE, is a model of short-term priming. ROUSE stands for Responding Optimally with Unknown Sources of Evidence, and it is able to explain an intricate pattern of results. (shrink)

Previous studies have demonstrated that orientation-specific deprivation in early life can lead to neural deficits of spatial vision in certain space, and can even result in meridional amblyopia. Individuals with astigmatism are the optimal and natural models for exploring this asymmetric development of spatial vision in the human visual system. This study aims to assess the contrast sensitivity function and EEG signals along two principal meridians in participants with regular astigmatism when being optimal optical corrected. Twelve participants with (...) astigmatism and thirteen participants with were recruited in the current study. CSFs and spatial sweep visual evoked potentials were measured with vertical and horizontal sinewave gratings along two principal meridians monocularly. Area under log CSF, spatial frequency threshold corresponding to 80% contrast gratings, and CSF acuity were calculated from CSF test. In addition, sVEP amplitudes and thresholds were calculated with the recursive least square method. Participants with astigmatism exhibited marked vertical-horizontal resolution disparities even after they were corrected with optimal optical corrections. CSF tests showed that AULCSF along weak meridian was lower than that along strong meridian in both groups. Significant meridional disparity of CSF acuity was also found in both groups. In addition, the MA group showed larger meridional disparity compared to the AST group. Spatial sVEP thresholds also supported the existence of marked meridional disparity. Our results suggest that meridian-specific partial deprivation in early life might lead to monocularly asymmetric development of spatial vision in the human visual system. In terms of application, we tested the feasibility and reliability of adopting psychophysical and EEG scalings to investigate the asymmetric development of spatial vision related to astigmatism. These paradigms are potentially applicable to reduce and even eliminate the meridional disparity in the primary visual cortex by adopting perceptual learning or other vision-related interventions. (shrink)

To avoid post-neurosurgical language deficits, intraoperative mapping of the language function in the brain can be complemented with preoperative mapping with functional magnetic resonance imaging. The validity of an fMRI “language localizer” paradigm crucially depends on the choice of an optimal language task and baseline condition. This study presents a new fMRI “language localizer” in Russian using overt sentence completion, a task that comprehensively engages the language function by involving both production and comprehension at the word and sentence level. (...) The paradigm was validated in 18 neurologically healthy volunteers who participated in two scanning sessions, for estimating test–retest reliability. For the first time, two baseline conditions for the sentence completion task were compared. At the group level, the paradigm significantly activated both anterior and posterior language-related regions. Individual-level analysis showed that activation was elicited most consistently in the inferior frontal regions, followed by posterior temporal regions and the angular gyrus. Test–retest reliability of activation location, as measured by Dice coefficients, was moderate and thus comparable to previous studies. Test–retest reliability was higher in the frontal than temporo-parietal region and with the most liberal statistical thresholding compared to two more conservative thresholding methods. Lateralization indices were expectedly left-hemispheric, with greater lateralization in the frontal than temporo-parietal region, and showed moderate test-retest reliability. Finally, the pseudoword baseline elicited more extensive and more reliable activation, although the syllable baseline appears more feasible for future clinical use. Overall, the study demonstrated the validity and reliability of the sentence completion task for mapping the language function in the brain. The paradigm needs further validation in a clinical sample of neurosurgical patients. Additionally, the study contributes to general evidence on test–retest reliability of fMRI. (shrink)

Humans have only finite discriminatory capacities. This simple fact seems to be incompatible with the existence of appearances. As many authors have noted, the hypothesis that appearances exist seems to be refuted by reductio: Let A, B, C be three uniformly coloured surfaces presented to a subject in optimal viewing conditions, such that A, B, and C resemble one another perfectly except with respect to their colours. Their colours differ slightly in the following way: the difference between A and (...) B and the difference between B and C are below the discrimination threshold, but the difference between A and C is above this threshold. According to an intuitive construal of what an appearance is, given that A and B appear (to the subject) identical in colour, A and B have the same (colour1) appearance P1; likewise, B and C have the same appearance P2. B's appearance is both P1 and P2. This seems to imply that P1=P2. But then, A and C also have the same appearance, which contradicts the hypothesis that A and C are discriminable. If A and C are discriminable with respect to their colour, they do not have the same appearance with respect to colour. The paradox arising from such a series of judgments of sameness or difference between pairs of coloured surfaces seems to belong to the class of sorites paradoxes. I will show that there is a way to construe colours and their appearances in a way that does not fall prey to the reduction just sketched. (shrink)

We study complex phenomena arising from a simple optimal choice consumer model, starting from the classical framework in Benhabib and Day :459–471, 1981). We introduce elements of increasing complexity and we investigate their effects on the resulting social behaviors. The dynamics introduce the dependence of current preferences on past consumers actions. A non-monotone updating preference function allows us to obtain a threshold effect, according to which the agents adopt a bandwagon/snob behavior if the preferences are below/above a certain (...) saturation level. We consider homogeneous and heterogeneous agents and we introduce local/global interaction when they are spatially distributed. We show through simulations several phenomena which are absent in the classical model and which reproduce significant social behaviors, such as path dependence, coexistence of different periodic and chaotic attractors, emergence of spatial patterns. (shrink)

The public health benefits of herd immunity are often used as the justification for coercive vaccine policies. Yet, ‘herd immunity’ as a term has multiple referents, which can result in ambiguity, including regarding its role in ethical arguments. The term ‘herd immunity’ can refer to (1) the herd immunity threshold, at which models predict the decline of an epidemic; (2) the percentage of a population with immunity, whether it exceeds a given threshold or not; and/or (3) the indirect (...) benefit afforded by collective immunity to those who are less immune. Moreover, the accumulation of immune individuals in a population can lead to two different outcomes: elimination (for measles, smallpox, etc) or endemic equilibrium (for COVID-19, influenza, etc). We argue that the strength of a moral obligation for individuals to contribute to herd immunity through vaccination, and by extension the acceptability of coercion, will depend on how ‘herd immunity’ is interpreted as well as facts about a given disease or vaccine. Among other things, not all uses of ‘herd immunity’ are equally valid for all pathogens. The optimal conditions for herd immunity threshold effects, as illustrated by measles, notably do not apply to the many pathogens for which reinfections are ubiquitous (due to waning immunity and/or antigenic variation). For such pathogens, including SARS-CoV-2, mass vaccination can only be expected to delay rather than prevent new infections, in which case the obligation to contribute to herd immunity is much weaker, and coercive policies less justifiable. (shrink)

The isolation requirements of the coronavirus epidemic and the intuitive display advantages of live-streaming have led to an increasing number of retailers shifting to social live-streaming platforms and e-commerce live-streaming platforms to promote and sell their products in real time. However, the provision of live-streaming services will also incur high live-streaming effort costs. In this paper, we develop two decision models for retailers to sell goods through a single online shop and both online shop and live-streaming room; we also present (...) the optimal decisions of pricing and live-streaming efforts. Furthermore, we identify the profitability conditions for retailers to determine when to provide live-streaming services. In addition, we examine the impact of the provision of live-streaming services on the optimal price and live-streaming effort. We obtain three findings. First, there is a unique optimal decision on the price and live-streaming effort under certain conditions. Second, when the effect coefficient of the live-streaming room reaches a certain threshold, there are enough customers who enter the live-streaming room to watch and buy and it is profitable for retailers to provide live-streaming service. Finally, the optimal price and live-streaming effort increase with the increase in average return loss, the effect coefficient of live-streaming effort, and the extra return rate and decrease with the increase in the proportion of customers who choose to buy in the online shop and the price discount coefficient in the live-streaming room. (shrink)

Previous studies revealed that the susceptibility, contacting preference, and recovery probability markedly alter the epidemic outbreak size and threshold. The recovery probability of an infected node is closely related to its obtained resources. How to allocate limited resources to infected neighbors is extremely important for containing the epidemic spreading on complex networks. In this paper, we proposed an epidemic spreading model on complex networks, in which we assume that the node has heterogeneous susceptibility and contacting preference, and susceptible nodes (...) are willing to share their resources to neighbors. Through a developed heterogeneous mean-field theory and a large number of numerical simulations, we find that the recovered nodes provide resources uniformly to their infected neighbor nodes, and the epidemic spreading can be suppressed optimally on homogeneous and heterogeneous networks. Besides, altering the susceptibility and contacting preference does not qualitatively change the results. The susceptibility of the node decreases, which makes the outbreak threshold of epidemic spreading increase, and the outbreak size decreases. Our theory agrees well with the numerical simulations. (shrink)

Herpes simplex virus type 2 is the most prevalent sexually transmitted infection in the world, despite the availability of effective anti-viral treatments. A mathematical model to explore the association between gender and HSV-2 treatment adherence is developed. Threshold parameters are determined and stabilities analyzed. Sensitivity analysis of the reproduction number and the numerical simulations suggest that treatment adherence for both females and males are equally important in keeping the reproduction as low as possible. The basic model is then extended (...) to incorporate time-dependent intervention strategies. The Pontryagin’s Maximum Principle is used to characterize the optimal level of the controls, and the resulting optimality system is solved numerically. (shrink)

Based on the adaptive particle swarm algorithm and error backpropagation neural network, this paper proposes methods for different styles of music classification and migration visualization. This method has the advantages of simple structure, mature algorithm, and accurate optimization. It can find better network weights and thresholds so that particles can jump out of the local optimal solutions previously searched and search in a larger space. The global search uses the gradient method to accelerate the optimization and control the real-time (...) generation effect of the music style transfer, thereby improving the learning performance and convergence performance of the entire network, ultimately improving the recognition rate of the entire system, and visualizing the musical perception. This kind of real-time information visualization is an artistic expression form, in which artificial intelligence imitates human synesthesia, and it is also a kind of performance art. Combining traditional music visualization and image style transfer adds specific content expression to music visualization and time sequence expression to image style transfer. This visual effect can help users generate unique and personalized portraits with music; it can also be widely used by artists to express the relationship between music and vision. The simulation results show that the method has better classification performance and has certain practical significance and reference value. (shrink)

The COVID-19 pandemic has negatively impacted the psychosocial functioning of children and families. It is important to consider adversity in relation to processes of positive adaptation. To date, there are no empirically validated multi-item scales measuring COVID-related positive adaptation within families. The aim of the current study was to develop and validate a new measure: the Family Positive Adaptation during COVID-19 Scale. The sample included 372 female and 158 male caregivers of children ages 5–18 years old from the United Kingdom, (...) the United States, Canada, and Australia, who completed measures in May 2020. Participants responded to a 14-item survey indexing a range of perceived coping and adaptation behaviors at the beginning of the pandemic. An exploratory factor analysis yielded an optimal one-factor solution comprised of seven items related to family cohesion, flexibility, routines, and meaning-making. Multigroup confirmatory factor analysis demonstrated measurement invariance across female and male caregivers, demonstrating that the factor structure, loadings, and thresholds did not vary by caregiver sex. There was evidence for concurrent validity with significant bivariate correlations between the Family PACS scores and measures of caregiver positive coping, parenting practices, couple satisfaction, and family functioning, but not negatively-valenced constructs. Findings inform our conceptualization of how families have adapted to adverse pandemic-related conditions. Further, we provide preliminary support for the Family PACS as a practical tool for evaluating positive family adaptation during this global crisis, with implications for future widespread crises. (shrink)

The cultivation of creativity in art education is not merely a cognitive or technical process but also a deeply philosophical and spiritual endeavor. Emotions, as integral components of human consciousness, play a crucial role in shaping artistic inspiration, imaginative expression, and the transcendent experience of creativity. This study explores the role of _multimodal affective computing_ in emotional guidance within art education, integrating philosophical and theological perspectives on creativity, inspiration, and the human experience of artistic expression. By analyzing the interaction between (...) emotions, cognition, and creativity, this research examines how computational technologies can facilitate a more profound engagement with artistic and spiritual dimensions in education. The study employs a personalized art teaching model based on multimodal affective computing, measuring students’ emotional intensity in real-time through multimodal data collection in fine arts classrooms. A comparative teaching experiment was conducted with fine arts students at a university, assessing their creativity development before and after the intervention. Through independent sample tests and regression analysis, the findings reveal that multimodal emotions have a significant positive impact on creativity at the 1% level. The emotional intensity thresholds for optimal artistic engagement were identified at 0.25 (positive) and -0.25 (negative), with students’ emotional distributions mostly ranging between [-0.2, 0.1]. After implementing the affective computing-supported teaching model, students in the experimental group demonstrated a _13.94-point_ increase in creativity scores, which was _17.67% higher_ than those in the control group. Beyond technological efficiency, this study reflects on the philosophical and spiritual implications of emotional engagement in artistic creation. Drawing on religious and metaphysical perspectives, it considers the role of emotions in fostering divine inspiration, self-transcendence, and artistic enlightenment. By enabling art educators to better understand students’ emotional states, multimodal affective computing can enhance emotional guidance in teaching, leading not only to improved artistic creativity but also to a deeper connection between artistic practice, spiritual growth, and philosophical reflection. Future research should explore how computational tools can further support the integration of spiritual and artistic experiences, enriching both pedagogical practice and the metaphysical dimensions of creativity. (shrink)

We study experimentally a coordination game with N heterogeneous individuals under different information treatments. We explore the effects of information on the emergence of Pareto-efficient outcomes, by means of a gradual decrease of the information content provided to the players in successive experiments. We observe that successful coordination is possible with private information alone, although not on a Pareto-optimal equilibrium. Reinforcement-based learning models reproduce the qualitative trends of the experimental results.

The fate of optimality modeling is typically linked to that of adaptationism: the two are thought to stand or fall together (Gould and Lewontin, Proc Relig Soc Lond 205:581–598, 1979; Orzack and Sober, Am Nat 143(3):361–380, 1994). I argue here that this is mistaken. The debate over adaptationism has tended to focus on one particular use of optimality models, which I refer to here as their strong use. The strong use of an optimality model involves the claim that selection is (...) the only important influence on the evolutionary outcome in question and is thus linked to adaptationism. However, biologists seldom intend this strong use of optimality models. One common alternative that I term the weak use simply involves the claim that an optimality model accurately represents the role of selection in bringing about the outcome. This and other weaker uses of optimality models insulate the optimality approach from criticisms of adaptationism, and they account for the prominence of optimality modeling (broadly construed) in population biology. The centrality of these uses of optimality models ensures a continuing role for the optimality approach, regardless of the fate of adaptationism. (shrink)

The background of this paper (section 1) consists in a new account to foundation‐theoretic epistemology characterized by two features: (i) All beliefs are to be justified by deductive, inductive or abductive inferences from a minimalistic class of unproblematic (introspective or analytic) basic beliefs. (ii) Higher‐order justifications for these inferences are given by means of the novel method of optimality justifications. Optimality justifications are a new tool for epistemology (section 2). An optimality justification does not attempt todemonstratethat a cognitive method is (...) reliable (which is impossible), but pursues the more modest goal of demonstrating that the method isoptimalamong all accessible alternative methods for the given epistemic goal. The reasoning from the established optimality of a method to the acceptability of a particular belief generated by the method is accomplished by so‐called optimality principles. In sections 3–5, the method of optimality justifications is carried out in detail for three fundamental problems: justifying induction, logic, and theory‐generating abduction. (shrink)

The prevalence of optimality models in the literature of evolutionary biology is testimony to their popularity and importance. Evolutionary biologist R. C. Lewontin, whose criticisms of optimality models are considered here, reflects that "optimality arguments have become extremely popular in the last fifteen years, and at present represent the dominant mode of thought." Although optimality models have received little attention in the philosophical literature, these models are very interesting from a philosophical point of view. As will be argued, optimality models (...) are central to evolutionary thought, yet they are not readily accomodated by the traditional view of scientific theories. According to the traditional view, we would expect optimality models to employ general, empirical laws of nature, but they do not. Fortunately, the semantic view of scientific theories, a recent alternative to the traditional view, more readily accomodates optimality models. As we would expect on the semantic view, optimality models can be construed as specifications of ideal systems. These specifications may be used to describe empirical systems--that is, the specifications may have empirical instances. But the specifications are not empirical claims, much less general, empirical laws. Although philosophers have yet to discuss the general features and uses of optimality models, these topics have stimulated much recent discussion among evolutionary biologists. Their discussions raise a number of precautions concerning the proper use of optimality models. Moreover, many of their caveats can be interpreted as general reminders that 1) optimality models specify ideal systems whose empirical instantiations may be quite restricted, and that 2) optimality models should not be construed as general, empirical laws. As G. F. Oster and E. O. Wilson caution, "the prudent course is to regard optimality models as provisional guides to further empirical research and not necessarily as the key to deeper laws of nature." It seems, then, that the semantic view of theories is more sensitive to the nature and limitations of optimality models than is the more traditional view of theories. (shrink)