The optimal investment problem is studied for a continuous time incomplete market model. It is assumed that the risk-free rate, the appreciation rates, and the volatility of the stocks are all random; they are independent from the driving Brownian motion, and they are currently observable. It is shown that some weakened version of Mutual Fund Theorem holds for this market for general class of utilities. It is shown that the supremum of expected utilities can be achieved (...) on a sequence of strategies with a certain distribution of risky assets that does not depend on risk preferences described by different utilities. (shrink)

The sharp changes in oil prices since 2004 featured a nonlinear data-generating mechanism which displayed bubble-like behavior. A popular view is that such a salient pattern cannot be explained by shifts in economic fundamentals, but was driven by speculative bubbles as a consequence of the increased financialization of oil future markets. Testing this hypothesis, however, is challenging since the fundamental component of the oil price is unobservable. This paper attempts to isolate the contribution of speculative bubbles and fundamentals to the (...) evolution of oil prices by providing a stylized model of commodity pricing. Motivated by our theoretical model, we adopt a continuous-time model with a random and time-varying persistence parameter to empirically investigate the presence of speculative bubbles in daily oil future prices over the period April 1983 to June 2020. We do not find any evidence in favor of speculative bubbles, although we indeed find that oil prices exhibit episodes of unstable behavior after 2004. (shrink)

This book offers a unified treatment of selected topics in the theory of financial markets. Starting with discrete time models, Dothan introduces discrete time stochastic calculus and discrete martingale methods of intuitive simplicity to characterize attainability, completeness, pricing, and the relationship between risk and return in financial markets. Subsequently, he uses the intuition developed in conjunction with the discrete time theory to introduce continuous time calculus for continuous, jump, and mixed continuous-jump processes, (...) and to deal with attainability, completeness, pricing, and the relationship between risk and return in general continuous time models. Throughout, the exposition of the continuous time theory emphasizes the analogies between discrete time and continuous time methods and results. The book includes many examples, applications to the pricing of options and other derivative securities, and an extensive discussion of the Black-Scholes model and its most general theoretical extension. (shrink)

Social entrepreneurship activity continues to surge tremendously in market and economic systems around the world. Yet, social entrepreneurship theory and understanding lag far behind its practice. For instance, the nature of the entrepreneurial discovery phenomenon, a critical area of inquiry in general entrepreneurship theory, receives no attention in the specific context of social entrepreneurship. To address the gap, we conceptualize social entrepreneurial discovery based on an extension of corporate social responsibility into social entrepreneurship contexts. We develop a model that (...) emphasizes mobilization and timing as underpinnings of social entrepreneurial discovery and offer distinct conceptual aspects and theoretic propositions instrumental to future social entrepreneurship research. (shrink)

We examine the comportment of the global trajectory of a piecewisely conceived single species population growth model. Formulation relies on what we develop as the principle of limiting factors for population growth, adapted from the law of the minimum of Liebig and the law of the tolerance of Shelford. The ensuing paradigm sets natality and mortality rates to express through extreme values of population growth determining factor. Dynamics through time occur over different growth phases. Transition points are interpreted as (...) thresholds of viability, starvation, and intraspecific competition. In this delivery, we focus on the qualitative study of the global trajectory expressed on continuous time and on exploring the feasibility of analytical results against data on populations growing under experimental or natural conditions. All study cases sustained fittings of high reproducibility both at empirical and interpretative slants. Possible phase configurations include regimes with multiple stable equilibria, sigmoidal growth, extinction, or stationarity. Here, we also outline that the associating discrete-time piecewise model composes the logistic map applied over a particular region of the phase configuration. Preliminary exploratory analysis suggests that the logistic map’s chaos onset could surpass once the orbit enters a contiguous phase region. (shrink)

It is widely held that the cure for such profound social maladies is within reach. The hopes have foundation. The past few years have seen the fall of brutal tyrannies, the growth of scientific understanding that offers great promise, and many other reasons to look forward to a brighter future. The discourse of the privileged is marked by confidence and triumphalism: the way forward is known, and there is no other. The basic theme, articulated with force and clarity, is that (...) "America's victory in the Cold War was a victory for a set of political and economic principles: democracy and the free market." These principles are "the wave of the future - a future for which America is both the gatekeeper and the model." I am quoting the chief political commentator of the New York Times , but the picture is conventional, widely repeated throughout much of the world, and accepted as generally accurate even by critics. It was also enunciated as the "Clinton Doctrine," which declared that our new mission is to "consolidate the victory of democracy and open markets" that had just been won. There remains a range of disagreement: at one extreme "Wilsonian idealists" urge continued dedication to the traditional mission of benevolence; at the other, "realists" counter that we may lack the means to conduct these crusades of "global meliorism," and should not neglect our own interests in the service of others.[2] Within this range lies the path to a better world. (shrink)

The problem of generalizing the power option-pricing model to incorporate more empirical features becomes an urgent and necessary event. A new power option pricing method is designed for the financial market uncertainty that simultaneously involves randomness and fuzziness. The randomness in market uncertainty is modeled by a time-fractional diffusion model, which describes trend memory in underlying asset prices. The fuzziness in market uncertainty is characterized by a triangular interval type-2 fuzzy numbers, which better captures the fuzziness (...) of underlying asset prices. Considering the decision-maker’s subjective judgment, we show the price mean value with the possibility-necessity weight and pessimistic-optimistic index under the type-2 fuzzy environment. We develop the power option pricing model with the time-fractional diffusion model and the triangular interval type-2 fuzzy numbers. Furthermore, the analytic solutions of pricing call power option and put power option are obtained and verified by the variational iterative reconstruction method. Our study shows that power option pricing, which adopts the time-fractional model and the triangular interval type-2 fuzzy numbers, can better capture the trend memory and double fuzziness of the real market. In addition, a numerical example is provided to illustrate that the power option means the value is decreasing with respect to the pessimistic-optimistic index and is fluctuating with respect to the possibility-necessity weight index. (shrink)

BackgroundSince 2006, the genetic testing company 23andMe has collected biological samples, self-reported information, and consent documents for biobanking and research from more than 1,000,000 individuals, through a direct-to-consumer online genetic-testing service providing a genetic ancestry report and a genetic health report. However, on November 22, 2013, the Food and Drug Administration halted the sale of genetic health testing, on the grounds that 23andMe was not acting in accordance with federal law, by selling tests of undemonstrated reliability as predictive tests for (...) medical risk factors. Consumers could still obtain the genetic ancestry report, but they no longer had access to the genetic health report in the United States. However, this did not prevent the company from continuing its health research, with previously obtained and future samples, provided that consent had been obtained from the consumers concerned, or with health reports for individuals from other countries. Furthermore, 23andMe was granted FDA authorization on February 19, 2015, first to provide reports about Bloom syndrome carrier status, and, more recently, to provide consumers with “carrier status” information for 35 genes known to cause disease.DiscussionIn this Debate, we highlight the likelihood that the primary objective of the company was probably two-fold: promoting itself within the market for predictive testing for human genetic diseases and ancestry at a low cost to consumers, and establishing a high-value database/biobank for research and personal information).SummaryBy dint of this marketing approach, a two-sided market has been established between the consumer and the research laboratories, involving the establishment of a database/DNA biobank for scientific and financial gain. We describe here the profound ethical issues raised by this setup. (shrink)

Contrary to widespread assumptions, post-truth politicians formally adopt a rhetoric of ‘truth’ but turn it against established experts. To explain one central factor behind this destructive strategy and its success with voters, I consider Walter Lippmann and Friedrich Hayek, who from 1922 onwards helped develop and popularize a political rhetoric of ‘truth’ in terms of scientific expertise. In Hayek’s influential version, market economics became the crucial expert field. Consequently, the 2008 financial crisis impacted attitudes towards experts more generally. But (...) even sweeping rejection of experts continues to use the rhetoric, by now dominant, of expert truth. Paradoxically, this bipartisan language fuels division as opponents accuse each other of disregarding ‘truth itself’. Against the underlying metaphysics of context-free ‘facts’, John Dewey and Alfred Schutz recommend understanding truth as ‘presumptive’ knowledge produced within human practices, which can be robust but requires a readiness to engage in pluralistic and open-ended processes of (re-)contextualization. (shrink)

Based on the assumption that the long-term value of a venture capital satisfies the algebraic Brownian motion, we develop a continuous-time exit model of venture capital under different exit modes, namely, initial public offering and mergers and acquisitions. The employee incentive problem is analyzed jointly with the exit decision of the firm in terms of the exit timing and the exit mode. Further, the problem of capital exit is considered from two perspectives, namely, optimal venture capital and social (...) welfare maximization, and the differences between these exit decisions are compared. Our model predicts that the timing of an IPO, the purpose of which is to maximize the utility of the capitalists, lags behind the exit timing, whose purpose is to maximize social welfare. Using a numerical analysis, this paper also proves that increasing the production efficiency, lowering the interest rates, and improving risk management can make the exit decision of venture capitalists converge with that of maximizing social welfare. (shrink)

Background Traditional top-down national regulation of internationally mobile doctors and nurses is fast being rendered obsolete by the speed of globalisation and digitisation. Here we propose a bottom-up system in which responsibility for hiring and accrediting overseas staff begins to be shared by medical employers, managers, and insurers. Discussion In this model, professional Boards would retain authority for disciplinary proceedings in response to local complaints, but would lose their present power of veto over foreign practitioners recruited by employers who have (...) independently evaluated and approved such candidates' ability. Evaluations of this kind could be facilitated by globally accessible National Registers of professional work and conduct. A decentralised system of this kind could also dispense with time-consuming national oversight of continuing professional education and license revalidation, which tasks could be replaced over time by tighter institutional audit supported by stronger powers to terminate underperforming employees. Summary Market forces based on the reputation (and, hence, financial and political viability) of employers and institutions could continue to ensure patient safety in the future, while at the same time improving both national system efficiency and international professional mobility. (shrink)

Decoherence is the name for the complex of phenomena leading to appearance of classical features of quantum systems. In the present paper decoherence in continuous measurements is analyzed with the help of restricted path integrals (RPI) and (equivalently in simple cases) complex Hamiltonians. A continuous measurement results in a readout giving information in the classical form on the evolution of the measured quantum system. The quantum features of the system reveal themselves in the variation of possible measurement readouts. (...) For example, the monitoring energy of a multi-level system may visualize a transition between levels as a process evolving in time but with an unavoidable quantum noise. Decoherence of a continuously measured system is completely determined by the measurement readout, i.e., by the information recorded in its environment. It is shown that the ideology of RPI makes the Feynman version of quantum mechanics closed, contrary to the conventional operator form of quantum mechanics which needs quantum theory of measurement as a necessary additional part. (shrink)

In the modern scientific literature, there are many reports about the successful application of neural network technologies for solving complex applied problems, in particular, for modeling the urban real estate market. There are neural network models that can perform mass assessment of real estate objects taking into account their construction and operational characteristics. However, these models are static because they do not take into account the changing economic situation over time. Therefore, they quickly become outdated and (...) need frequent updates. In addition, if they are designed for a specific city, they are not suitable for other cities. On the other hand, there are several dynamic models taking into account the overall state of the economy and designed to predict and study the overall price situation in real estate markets. Such dynamic models are not intended for mass real estate appraisals. The aim of this article is to develop a methodology and create a complex model that has the properties of both static and dynamic models. Moreover, our comprehensive model should be suitable for evaluating real estate in many cities at once. This aim is achieved since our model is based on a neural network trained on examples considering both construction and operational characteristics, as well as geographical and environmental characteristics, along with time-changing macroeconomic parameters that describe the economic state of a specific region, country, and the world. A set of examples for training and testing the neural network were formed on the basis of statistical data of real estate markets in a number of Russian cities for the period from 2006 to 2020. Thus, many examples included the data relating to the periods of the economic calm for Russia, along with the periods of crisis, recovery, and growth of the Russian and global economy. Due to this, the model remains relevant with the changes of the international economic situation and it takes into account the specifics of regions. The model proved to be suitable for solving the following tasks: industrial economic analysis, company strategic and operational management, analytical and consulting support of investment, and construction activities of professional market participants. The model can also be used by government agencies authorized to conduct public cadastral assessment for calculating property taxes. (shrink)

Research in the neurosciences continues to provide evidence that sleep plays a role in the processes of learning and memory. There is less of a consensus, however, regarding the precise stages of memory development during which sleep is considered a requirement, simply favorable, or not important. This article begins with an overview of recent studies regarding sleep and learning, predominantly in the procedural memory domain, and is measured against our current understanding of the mechanisms that govern memory formation. Based on (...) these considerations, I offer a new neurocognitive framework of procedural learning, consisting first of acquisition, followed by two specific stages of consolidation, one involving a process of stabilization, the other involving enhancement, whereby delayed learning occurs. Psychophysiological evidence indicates that initial acquisition does not rely fundamentally on sleep. This also appears to be true for the stabilization phase of consolidation, with durable representations, resistant to interference, clearly developing in a successful manner during time awake (or just time, per se). In contrast, the consolidation stage, resulting in additional/enhanced learning in the absence of further rehearsal, does appear to rely on the process of sleep, with evidence for specific sleep-stage dependencies across the procedural domain. Evaluations at a molecular, cellular, and systems level currently offer several sleep specific candidates that could play a role in sleep-dependent learning. These include the upregulation of select plasticity-associated genes, increased protein synthesis, changes in neurotransmitter concentration, and specific electrical events in neuronal networks that modulate synaptic potentiation. Key Words: consolidation; enhancement; learning; memory; plasticity; sleep; stabilization. (shrink)

This study introduces 'time-specific' analysis of economic processes. Economic processes are conventionally analysed from one point in time to another over a series of time units - days, weeks, or years. By contrast, these time-specific models focus on the temporal character of events within the unit time - their timing, duration, and sequence - utilizing the information that is lost in the macroscopic time perspective of standard economic theory. What time-specific analysis reveals (...) are economic and technological characteristics of goods and services - prices and cost behaviour and temporal mobility or immobility within the unit time - that affect capital productivity and its utilization, optimal schedules of production, work, and consumption, least-cost methods of producing time-shaped outputs, and efficient welfare-maximizing behavior in time-specific, including peak-load, markets. (shrink)

In this work we consider the problem of the approximate hedging of a contingent claim in the minimum mean square deviation criterion. A theorem on martingale representation in case of discrete time and an application of the result for semi-continuous market model are also given.

Most models of response time (RT) in elementary cognitive tasks implicitly assume that the speed-accuracy trade-off is continuous: When payoffs or instructions gradually increase the level of speed stress, people are assumed to gradually sacrifice response accuracy in exchange for gradual increases in response speed. This trade-off presumably operates over the entire range from accurate but slow responding to fast but chance-level responding (i.e., guessing). In this article, we challenge the assumption of continuity and propose a phase (...) transition model for RTs and accuracy. Analogous to the fast guess model (Ollman, 1966), our model postulates two modes of processing: a guess mode and a stimulus-controlled mode. From catastrophe theory, we derive two important predictions that allow us to test our model against the fast guess model and against the popular class of sequential sampling models. The first prediction—hysteresis in the transitions between guessing and stimulus-controlled behavior—was confirmed in an experiment that gradually changed the reward for speed versus accuracy. The second prediction—bimodal RT distributions—was confirmed in an experiment that required participants to respond in a way that is intermediate between guessing and accurate responding. (shrink)

In these two lectures, first published in 1994, Peter Diamond explores how time is modelled in theoretical analyses of individual industries and of an entire economy. In the first lecture he considers equilibrium in a single market by examining the distinction between the short run and the long run in Marshallian analysis. He proposes an explicit modelling of time in place of Marshall's use of different atemporal models for different time frames. In the second lecture (...) he turns to models of an entire economy, and begins by considering how and why models of an entire economy should differ from models of a single industry. Both cyclical and seasonal data on the behaviour of macro-economies are examined. (shrink)

The article analizes the several times of Proclus‘s reception by Nicholas of Cusa’s thought. The direct reading of Proclus can be established because Expositio in Parmenidem Platonis –Cod.Cus. 186– and Elementatio theological –Cod.Cus.195– (Moerbeke’s translation) and De theologia Platonis Libri VI –Cod.Cus.185– (Petrus Balbus’s translation) are in his Library in Bernkastel-Kues with his marginalia. The assimilation of doctrines can be considered assuming that the implicits and explicits references to Plato’s Diadochus, especially in the last works.

In the industrial context, steel is a broadly-used raw material with applications in many different fields. Due to its high impact in the activity of many industries all over the world, forecasting its price is of utmost importance for a huge amount of companies. In this work, non-linear neural models are applied for the first time to different datasets in order to validate their suitability when predicting the price of this commodity. In particular, the NAR, NIO and NARX (...) neural network models are innovatively applied for the first time to forecast the price of hot rolled steel in Spain. Besides these variety of models, different datasets consisting of a set of heterogenous variables from the last seven years and related to the price of this commodity are benchmarked and analyzed. The results showed that NARX is the best performing model when the price of raw materials used to produce steel and the stock market prices of three major global steel producing companies are employed as input to this predictive model. Consequently, this result may boost the application of Machine Learning in companies, in order to schedule the supplying operations according to the price forecasting. (shrink)

For some time we have seen a shift away from direct marketing, a core feature and dominant exchange form in the alternative food world, towards a greater role for intermediation. Yet, we still need to better understand to what extent and in what ways new mediated Alternative Food Networks represent an evolution of or departure from core tenets of alternative food systems. This paper focuses on AFNs with new intermediaries that connect small-scale producers with urban end-consumers. Based on original (...) research in Frankfurt, Berlin, and Calgary, we analyze three different types of mediated AFNs: one driven by consumers, one by an external intermediary, and one by producers. Our cases include non-capitalist, capitalist, and alternative capitalist economic practices as identified by Gibson-Graham. Conceptually, we base our analysis on the three-pillar-model of alternative agri-food systems, which we further refine. Besides comparing our cases with each other, for heuristic purposes we also compare them with an ideal-type model that adheres to core tenets of alterity in all three pillars. Our empirical analysis shows that intermediary organizations can bring important benefits and that mediated AFNs are in principle able to hold true to the core tenets of alternative agri-food systems. However, it is very important to develop models of democratic control and ownership as well as economic arrangements in which created value is fairly shared. Only then can the potentials of new mediated models be realized while the pitfalls of the conventional systems they seek to replace be avoided. (shrink)

Recent treatments of time in husserl purport to give an account of the most fundamental aspects of what husserl terms inner time-Consciousness, The immanent temporality that is the primal constitutive source of human experience. A major difficulty with these presentations of husserl's time-Theory is that they continue to use theoretically reductionist models for time, Based on a sense of "flow" that is drawn from objective-Physical space and objects extended through such space. Such treatments fail to (...) capture the very heart of the flowing-Processing itself. To clarify this point, This paper investigates the two-Fold description of inner time-Consciousness that gives the primary spatial model of flow--In fact, Of two intersecting flows. Next, It considers the manner in which aspects of immanent temporality are overlooked in this spatial model. Finally, Another spatial model is proposed, One that can harness the complexity of husserl's theory of immanent temporality and explain the very source of process as processing. (shrink)

In this chapter, one considers finance at its very foundations, namely, at the place where assumptions are being made about the ways to measure the two key ingredients of finance: risk and return. It is well known that returns for a large class of assets display a number of stylized facts that cannot be squared with the traditional views of 1960s financial economics (normality and continuity assumptions, i.e. Brownian representation of market dynamics). Despite the empirical counterevidence, normality and continuity (...) assumptions were part and parcel of financial theory and practice, embedded in all financial practices and beliefs. Our aim is to build on this puzzle for extracting some clues revealing the use of one research strategy in academic community, model tinkering defined as a particular research habit. We choose to focus on one specific moment of the scientific controversies in academic finance: the ‘leptokurtic crisis’ opened by Mandelbrot in 1962. The profoundness of the crisis came from the angle of the Mandelbrot’s attack: not only he emphasized an empirical inadequacy of the Brownian representation, but also he argued for an inadequate grounding of this representation. We give some insights in this crisis and display the model tinkering strategies of the financial academic community in the 1970s and the 1980s. (shrink)

The Catholic Church – though in popular opinion it is sometimes treated as a stronghold of conservatism, traditionalism, suspicion of progress and novelty, it changed significantly in the second half of the 20th century and continues to change its attitudes, especially in terms of the use of social communication and attitude to the media mass. The Church’s growing openness to media relations and the use of a rich instrumentation of social communication has become one of the reasons for the growing (...) popularity of market orientation among the clergy and active believers, which opens opportunities for the development of the concept of a specific sectoral marketing formula of church marketing. In this article the authors search for the causes of the progressive phenomenon of the marketization of religion, present examples of the activities of the Polish Catholic church, inscribed in the church marketing trend, as well as define the negative consequences resulting from its dissemination. The applied research method is based on the literature analysis and case studies analysis. (shrink)

A general approach to the synthesis of an optimal order of executing jobs in engineering systems with indeterminate times of job processing is presented. As a mathematical model of the system, a two-stage pipeline is taken whose first and second stages are, respectively, the input of data and its processing, and the corresponding mathematical apparatus is continuous logic and logic determinants.

As far as we are aware, this study presents the first comparative analysis of the stock picking and market timing abilities of managers of conventional and socially responsible (SR) pension funds, and of their use of superior information. For the United Kingdom, the results obtained show a slight stock picking ability on the part of SR pension fund managers (although it disappears if multifactorial models are considered), and a negative market timing ability on the part of both (...) SR and conventional pension fund managers (these results hold for multifactorial models controlled by home bias). In relation to the management styles, both conventional and SR pension funds usually invest in small cap and growth values, although it is the SR pension funds that are the most exposed to these styles. We also observed that, while conventional pension fund managers make certain use of superior information to follow stock picking strategies, managers of SR pension funds use superior information to follow market timing strategies. (shrink)

This article answers the question raised by the special issue of this journal in a positive way: managerial practices do need philosophy. In particular, it argues for a more concrete claim: managerial practices have needed philosophy in the past to develop some important intellectual tools, and today they still need to be open to the continuous conceptual and methodological innovations introduced by competing philosophical research programmes, because loyalty to just one favourite philosophical paradigm can hinder the ability of managerial (...) practices to express their full potential, whereas openness to philosophical innovation can help managers keep their conceptual tools up to their tasks. The authors argue for this thesis in concreto: they discuss a specific branch of managerial practice—marketing—and illustrate that a preeminent form thereof, i.e. Experiential Marketing, has needed philosophy, and still needs it nowadays, in order to achieve its goals and overcome certain problems. They also point out that Experiential Marketing needs to renew and integrate some of its philosophical assumptions and conceptual tools in the light of innovations brought about by a recent philosophical turn. In particular, the authors argue that philosophy has provided essential conceptual tools for the articulation of the notions of experience and authenticity used in Experiential Marketing; they claim that the excessive reliance of Experiential Marketing upon a problematic and somewhat outdated ontology produces paradoxes with important repercussions upon managerial practice; and they show that those problems can be overcome by integrating and partially renewing its assumptions and conceptual tools, in the light of a fresher philosophical framework. Shortcomings and solutions are discussed with reference to a specific case study: Venice as an experientially rewarding and authentic tourist destination during the Covid19 crisis, but also as a World Heritage property whose management entails difficult choices. The fruitfulness of the paradigm revision is shown also by integrating the conceptual toolkit of Experiential Marketing with three relatively new notions, deriving from a new realist framework: independence, attrition and perception. (shrink)

This paper examines the shaping factors, drivers, and impact credentials of students’ entrepreneurial intention during the COVID-19 pandemic. The proposed framework addresses the antecedents of entrepreneurial intention among students in Romania, focusing on three focal constructs, namely, risk-taking, proactiveness, and innovativeness, with a keen focus on the mediation effect of the entrepreneurial university environment. The study used self-reported data collected through an online questionnaire during November 2020–February 2021 from a sample of 1,411 students in western Romania. The methodology relies on (...) two modern techniques of modeling cross-sectional data, namely, structural equation modeling and Gaussian graphical models. The main results highlight that the three constructs positively relate to students’ entrepreneurial intention in a comprehensive framework where the entrepreneurial university environment drives innovativeness. The paper brings forward, in an innovative way, that entrepreneurship education and training at the university level enhance students’ entrepreneurial intentions as it fosters the attainment of advanced knowledge and skills. The results are well associated with the start-up process as prerequisites for successful entrepreneurship engagement of youth in a globalized digital economy, particularly during this challenging pandemic outbreak, but also post-pandemic times. This research sheds new light on the essential role played by higher education institutions in providing advanced knowledge and necessary skills matched with the labor market needs, thus enhancing students’ innovativeness and their entrepreneurial intentions. (shrink)

An extension to a rating system for tracking the evolution of parameters over time using continuous variables is introduced. The proposed rating system assumes a distribution for the continuous responses, which is agnostic to the origin of the continuous scores and thus can be used for applications as varied as continuous scores obtained from language testing to scores derived from accuracy and response time from elementary arithmetic learning systems. Large-scale, high-stakes, online, anywhere anytime learning (...) and testing inherently comes with a number of unique problems that require new psychometric solutions. These include (1) the cold start problem, (2) problem of change, and (3) the problem of personalization and adaptation. We outline how our proposed method addresses each of these problems. Three simulations are carried out to demonstrate the utility of the proposed rating system. (shrink)

We present a mathematical bioeconomic model of a fishery with a variable price. The model describes the time evolution of the resource, the fishing effort and the price which is assumed to vary with respect to supply and demand. The supply is the instantaneous catch while the demand function is assumed to be a monotone decreasing function of price. We show that a generic market price equation (MPE) can be derived and has to be solved to calculate non (...) trivial equilibria of the model. This MPE can have 1, 2 or 3 equilibria. We perform the analysis of local and global stability of equilibria. The MPE is extended to two cases: an age-structured fish population and a fishery with storage of the resource. (shrink)

The foremost aim of this research was to forecast the performance of three stock market indices using the multilayer perceptron, recurrent neural network, and autoregressive integrated moving average on historical data. Moreover, we compared the extrapolative abilities of a hybrid of ARIMA with MLP and RNN models, which are called ARIMA-MLP and ARIMA-RNN. Because of the complicated and noisy nature of financial data, we combine novel machine-learning techniques such as MLP and RNN with ARIMA model to predict the (...) three stock market data. The data used in this study are taken from the Pakistan Stock Exchange, National Stock Exchange India, and Sri Lanka Stock Exchange. In the case of Pakistan, the findings show that the ARIMA-MLP and ARIMA-RNN beat the individual ARIMA, MLP, and RNN models in terms of accuracy. Similarly, in the case of Sri Lanka and India, the hybrid models show more robustness in terms of forecasting than individual ARIMA, MLP, and RNN models based on root-mean-square error and mean absolute error. Apart from this, ARIMA-MLP outperformed the ARIMA-RNN in the case of Pakistan and India, while in the context of Sri Lanka, ARIMA-RNN beat the ARIMA-MLP in forecasting. Our findings reveal that the hybrid models can be regarded as a suitable option for financial time-series forecasting. (shrink)

I begin by recounting the market demands that created an opportunity for me to teach business ethics in the College of Business at St. Cloud State University. The AACSB and my educational institution focused amorphous social demands for better business practices into a specific demand for a philosophy Ph.D. to teach business ethics. I felt frustrated teaching business ethics because of my inexperience and the eclectic nature of the field. I, and many others, searched for something to unify the (...) many topics of the field. This search was one of the factors that led to BEQ’s appearance in 1991. The first issue marked a milestone in the continuing search fortheory and the legitimization of the field. It focused previous discussions and was remarkably prescient. While it is unlikely that we will reach a consensus about how to understand the field, if consensus ever comes close to occurring, I argue that it will not coalesce over stakeholder theory. I examine two theories that could be used as a grand unified theory (GUT) of business ethics: Integrated Social Contracts Theory and my own institutional theory that expands on the work of Douglass North’s view of economic institutions. I usethe discussion of these GUTs to develop criteria of what a successful GUT might look like. Based on these criteria, I argue that theinstitutional theory has a better chance of succeeding, but recognize that business ethics GUTs are primarily heuristic; many different types of theories can be helpful. Lastly, I discuss whether it is pretentious and overbearing to argue for a GUT. I argue that it need not be. (shrink)

Aggregation of variables allows to approximate a large scale dynamical system (the micro-system) involving many variables into a reduced system (the macro-system) described by a few number of global variables. Approximate aggregation can be performed when different time scales are involved in the dynamics of the micro-system. Perturbation methods enable to approximate the large micro-system by a macro-system going on at a slow time scale. Aggregation has been performed for systems of ordinary differential equations in which time (...) is a continuous variable. In this contribution, we extend aggregation methods to time-discrete models of population dynamics. Time discrete micro-models with two time scales are presented. We use perturbation methods to obtain a slow macro-model. The asymptotic behaviours of the micro and macro-systems are characterized by the main eigenvalues and the associated eigenvectors. We compare the asymptotic behaviours of both systems which are shown to be similar to a certain order. (shrink)

The paper continues the model I began in a previous issue of Sophia . It is argued that the predominance of purely ascending or ‘top down’ forms of spirituality which stemmed largely from the axial period and have been carried forward into modern, transpersonal theories of evolutionary spirituality is a mistake and that there exists a lost or largely ignored form of spirituality—which I name somatic—which was the predominant domain of early Neolithic and Palaeolithic experience. Aspects of what I call (...) somatic mystical experiences have certainly been acknowledged at times to a limited degree, though they have rarely been fully explored, and have usually been considered as basic to other kinds of mystical experience, rather than fully developed forms in their own right. This article offers a fuller exploration and places such states more accurately within a detailed developmental framework than has previously been the case. Other issues relating to the horizon model across the two papers are also expanded. (shrink)

First the Branching Space-time and Branching Continuations mod-els are briefly presented. We compare their properties with the traditional definition of a Flow of Time from physics and we point out the difficulties of it in relativistic time. A solution of a Flow of Time in the given models is then proposed.

Aristotle is oftentimes viewed through a strictly philosophical lens as heir to Plato and has having introduced logical rigor where an emphasis on the theory of Forms formerly prevailed. It must be appreciated that Aristotle was the son of a physician, and that his inculcation of the thought of other Greek philosophers addressing health and the natural elements led to an extremely broad set of biologically- and medically-related writings. As this article proposes, Aristotle deepened the fourfold theory of the elements (...) with anatomic and physiologic observations. In books like History of Animals, Parts of Animals, and the lost Anatomai, he actively dissected organisms and recorded his findings. The corpus of medically-related literature Aristotle developed had a direct influence on subsequent Greek thinkers, including Galen, and on Medieval Islamic and modern Western practitioners such as William Harvey. Aristotle's ideas continue to influence modern medical thinkers in Europe and America through both his interpretation by European philosophers gaining the attention of medical humanists, and his writings' enduring impact on medical researchers balancing scientific with more personalistic approaches to medicine. (shrink)

Tetris provides a difficult, dynamic task environment within which some people are novices and others, after years of work and practice, become extreme experts. Here we study two core skills; namely, choosing the goal or objective function that will maximize performance and a feature-based analysis of the current game board to determine where to place the currently falling zoid so as to maximize the goal. In Study 1, we build cross-entropy reinforcement learning models to determine whether different goals result (...) in different feature weights. Two of these optimization strategies quickly rise to performance plateaus, whereas two others continue toward higher but more jagged heights. In Study 2, we compare the zoid placement decisions made by our best CERL models with those made by 67 human players. Across 370,131 human game episodes, two CERL models picked the same zoid placements as our lowest scoring human for 43% of the placements and as our three best scoring experts for 65% of the placements. Our findings suggest that people focus on maximizing points, not number of lines cleared or number of levels reached. They also show that goal choice influences the choice of zoid placements for CERLs and suggest that the same is true of humans. Tetris has a repetitive task structure that makes Tetris more tractable and more like a traditional experimental psychology paradigm than many more complex games or tasks. Hence, although complex, Tetris is not overwhelmingly complex and presents a right-sized challenge to cognitive theories, especially those of integrated cognitive systems. (shrink)

Tetris provides a difficult, dynamic task environment within which some people are novices and others, after years of work and practice, become extreme experts. Here we study two core skills; namely, choosing the goal or objective function that will maximize performance and a feature-based analysis of the current game board to determine where to place the currently falling zoid so as to maximize the goal. In Study 1, we build cross-entropy reinforcement learning models to determine whether different goals result (...) in different feature weights. Two of these optimization strategies quickly rise to performance plateaus, whereas two others continue toward higher but more jagged heights. In Study 2, we compare the zoid placement decisions made by our best CERL models with those made by 67 human players. Across 370,131 human game episodes, two CERL models picked the same zoid placements as our lowest scoring human for 43% of the placements and as our three best scoring experts for 65% of the placements. Our findings suggest that people focus on maximizing points, not number of lines cleared or number of levels reached. They also show that goal choice influences the choice of zoid placements for CERLs and suggest that the same is true of humans. Tetris has a repetitive task structure that makes Tetris more tractable and more like a traditional experimental psychology paradigm than many more complex games or tasks. Hence, although complex, Tetris is not overwhelmingly complex and presents a right-sized challenge to cognitive theories, especially those of integrated cognitive systems. (shrink)

Contemporary debates about scientific institutions and practice feature many proposed reforms. Most of these require increased efforts from scientists. But how do scientists’ incentives for effort interact? How can scientific institutions encourage scientists to invest effort in research? We explore these questions using a game-theoretic model of publication markets. We employ a base game between authors and reviewers, before assessing some of its tendencies by means of analysis and simulations. We compare how the effort expenditures of these groups interact in (...) our model under a variety of settings, such as double-blind and open review systems. We make a number of findings, including that open review can increase the effort of authors in a range of circumstances and that these effects can manifest in a policy-relevant period of time. However, we find that open review’s impact on authors’ efforts is sensitive to the strength of several other influences. (shrink)

The discrete-time system has more complex and chaotic dynamical behaviors as compared to the continuous-time system. This paper extends a discrete Leslie–Gower predator-prey system with the Allee effect in the predator’s population, whose dynamics are analyzed and explored. We have determined the equilibrium points and studied their local stability properties. We find that the system undergoes flip bifurcation and Neimark–Sacker bifurcation around the interior equilibrium point by choosing the Allee parameter as a bifurcation parameter. We discuss the (...) stability and direction of both bifurcations with the help of the normal form theory and center manifold theorem. The flip bifurcation and Neimark–Sacker bifurcation are the most common routes to the chaotic orbit in the discrete system. Moreover, we utilize state feedback, pole placement, and hybrid control methods to control the chaos in the system. The work is complete with the numerical simulations to confirm the analytical findings. (shrink)

Electricity is an indicator that shows the progress of a civilization; it is a product that has greatly changed the way we think about the world. Electricity price forecasting became a fundamental task in all countries due to the deregulation of the electricity market in the 1990s. This work examines the effectiveness of using multiple variables for price prediction given the large number of factors that could influence the price of the electricity market. The tests were carried out (...) over four periods using data from Spain and deep learning models. Two different attribute selection methods based on Pearson’s correlation coefficient have been used to improve the efficiency of the training process. The variables used as input to the different prediction models were chosen, considering those most commonly used previously in the literature. This study attempts to test whether using time series lags improves the non-use of lags. The results obtained have shown that lags improve the results compared to a previous work in which no lags were used. (shrink)

Between December 2020 and March 2021, the US Food and Drug Administration and the European Medicines Agency issued Emergency Use Authorizations and Conditional Marketing Authorizations for the distribution of the first COVID-19 vaccines. Although these vaccines were thoroughly assessed before their approval, regulators required companies to continue ongoing placebo-controlled clinical trials in order to gather further reliable scientific information on their safety and efficacy, as well as to start new studies to evaluate additional candidates. The aim of this paper is (...) to present and discuss the ethical issues raised by the tension between the need to continue these types of clinical trials and the obligations related to the protection of the rights and well-being of research participants. Specifically, we question whether—how, and to what extent—fundamental principles governing research involving human beings can be applied to the current pandemic situation. We argue that continuing ongoing placebo-controlled clinical trials can be considered ethically justifiable only if all participants are adequately informed of any developments that may affect their willingness to remain enrolled, including the current situation of resource scarcity and the prioritization criteria established for vaccination. However, we also argue that currently approved vaccines, which are considered safe and effective enough to be administered to millions of people as part of the vaccination campaign, necessarily represent the “best proven intervention” currently available and, therefore, should be used as comparators in future studies instead of placebo. (shrink)

Models are of central importance in many scientific contexts. The centrality of models such as inflationary models in cosmology, general-circulation models of the global climate, the double-helix model of DNA, evolutionary models in biology, agent-based models in the social sciences, and general-equilibrium models of markets in their respective domains is a case in point (the Other Internet Resources section at the end of this entry contains links to online resources that discuss these (...) class='Hi'>models). Scientists spend significant amounts of time building, testing, comparing, and revising models, and much journal space is dedicated to interpreting and discussing the implications of models. In short, models are one of the principal instruments of modern science. (shrink)

This chapter explores to what extent some core ideas of predictive processing can be applied to the phenomenology of time consciousness. The focus is on the experienced continuity of consciously perceived, temporally extended phenomena (such as enduring processes and successions of events). The main claim is that the hierarchy of representations posited by hierarchical predictive processing models can contribute to a deepened understanding of the continuity of consciousness. Computationally, such models show that sequences of events can be (...) represented as states of a hierarchy of dynamical systems. Phenomenologically, they suggest a more fine-grained analysis of the perceptual contents of the specious present, in terms of a hierarchy of temporal wholes. Visual perception of static scenes not only contains perceived objects and regions but also spatial gist; similarly, auditory perception of temporal sequences, such as melodies, involves not only perceiving individual notes but also slightly more abstract features (temporal gist), which have longer temporal durations (e.g., emotional character or rhythm). Further investigations into these elusive contents of conscious perception may be facilitated by findings regarding its neural underpinnings. Predictive processing models suggest that sensorimotor areas may influence these contents. (shrink)

In this paper we will show how “weighted path integral” proposed by Mensky and Kent can emerge out of Ghirardi Rimini Weber model.

This paper outlines the demographic characteristics of the Baiga tribe, one of the most primitive of the aboriginal tribal groups of Central India. The Baiga population has grown steadily since the first anthropological study of the tribe in the 1930s. Age at menarche, age at marriage, breast-feeding, and time interval between marriage and first conception are natural. There are more females than males. Sub-tribe endogamy is common; consanguineous marriage is favoured (34% of marriages are between first cousins) and marital (...) distance is low (mean 7·1 km). Though the mean menarcheal age is high (15·2 years), mean age at first marriage is low (16·6 years), giving a long reproductive period. (shrink)

Regional market integration in Europe and North America has grown increasingly extensive. This integration has created institutions and structures to guide pancontinental political, economic, and social policies. At the same time, both regions are experiencing pressures of decentralization. These competing trends are transforming relationships between and among business, society, and government. This article compares and contrasts integration in North America and Europe, and discusses the implications of political, economic, and institutional changes in these two regions for business-government relations (...) and the structure and strategic orientation of the corporate public affairs (PA) function. This article reviews recent literature on comparative political economy, business and public policy, and corporate PA, and it presents a conceptual model and research propositions, supported by case illustrations, of how integration and decentralization affect business-government relations and corporate PA in Europe and North America. (shrink)