Logics of communication should provide accounts of changes in the state of information of a group of discourse participants, on the basis of message exchanged within the group. We will give an overview of the way this is done in dynamic epistemic logic, focussing on a number of different types of informative actions with their epistemic effects, and presenting a number of new results. At the end of the talk we will indicate the relevance of this work for semantics (...) and pragmatics of natural language. (shrink)

The economic crisis happening across the world over the last few years describes a range of interdependencies and interactions,and has highlighted the fundamentalf laws of neoclassical economic theory: its unedifying focus on prediction and, above all, its inability to explain how the economy really works. As such, it is increasingly recognised that economic phenomena cannot be exclusively investigated as being derived from deterministic, predictable and mechanistic dynamics. Instead, a new approach is required by which history-dependence, organic and ever-evolving processes are (...) also accounted for. As this view implies new challenges and opportunities for policy, we will focus our attention on innovative components of Complexity Theory for the study of economics and the evaluation of public policies. (shrink)

A modified version of the SEIR model with the effects of vaccination and inter-state movement is proposed to simulate the spread of COVID-19 in Malaysia. A mathematical analysis of the proposed model was performed to derive the basic reproduction number. To enhance the model’s forecasting capabilities, the model parameters were estimated using the Nelder–Mead simplex method by fitting the model outputs to the observed data. Our results showed a good fit between the model outputs and available data, where the (...) model was then able to perform short-term predictions. In line with the rapid vaccination program, our model predicted that the COVID-19 cases in the country would decrease by the end of August. Furthermore, our findings indicated that relaxing travel restrictions from a highly vaccinated region to a low vaccinated region would result in an epidemic outbreak. (shrink)

This volume brings together contributions from leading researchers in the field of agent-based modelling and simulation. This approach has grown out of some recent and innovative ideas in the social sciences, computer sciences, life sciences, physics and game theory. It is proving helpful in understanding complexity in many domains. The opportunities it offers to explore the experimental approach to social and human behaviour is proving of theoretical and empirical value across a wide range of fields. With contributions from researchers whose (...) work has served to define this new field such as Nigel Gilbert, Robert Axtell (in economics and social science) and Jacques Ferber (in multi-agent systems), as well as practitioners who are working at the cutting edge of the new domain, this collection of essays has been assembled by two of its leading exponents: Frédéric Amblard and Denis Phan. The research, case studies and theoretical approaches discussed in this book are designed to introduce beginners and experts alike to the current state of play in this new and exciting field of social science. (shrink)

This book brings together contributions from leading researchers in the field of agent-based modelling and simulation. This approach has grown out of some recent and innovative ideas in the social sciences, computer sciences, life sciences, physics and game theory. It is proving helpful in understanding complexity in many domains. The opportunities it offers to explore the experimental approach to social and human behaviour is proving of theoretical and empirical value across a wide range of fields. With contributions from researchers whose (...) work has served to define this new field such as Nigel Gilbert, Robert Axtell (in economics and social science) and Jacques Ferber (in multi-agent systems), as well as practitioners who are working at the cutting edge of the new domain, this collection of essays has been assembled by two of its leading exponents: Frédéric Amblard and Denis Phan. The research, case studies and theoretical approaches discussed in this book are designed to introduce beginners and experts alike to the current state of play in this new and exciting field of social science. (shrink)

This article brings together two different topics: reflective equilibrium (RE) and belief revision theory (BRT). RE is a popular method of justification in many areas of philosophy, it involves a process of mutual adjustments striving for a state of coherence, but it lacks formally rigorous elaborations and faces severe criticism. To elucidate core elements of RE and provide a solid basis to address objections, a formal model of RE within BRT is presented. A fruitful starting point to the formalization (...) of RE is Olsson’s coherentist interpretation of semi-revision, but it does not come with a comparative notion of stability. This paper develops an account of comparative stability in an RE setting for belief changing operations. The operations are useful to characterize RE states as well as processes, and they are shown to satisfy postulates of rational belief change. (shrink)

I investigate: to what extent do folk ascriptions of lying differ between casual and courtroom contexts? to what extent does motive to lie influence ascriptions of trust, mental states, and lying judgments? to what extent are lying judgments consistent with previous ascriptions of communicated content? Following the Supreme Court’s Bronston judgment, I expect: averaged lying judgments to be similar in casual and courtroom contexts; motive to lie to influence levels of trust, mental states ascriptions, and patterns of lying judgments; retrospective (...) judgments of lying, after being presented with the state of the world, to be inconsistent with previous judgments of communicated content: participants hold the protagonist responsible for content she did not communicate. I performed a survey experiment on the Qualtrics platform. Participants were recruited through Amazon Mechanical Turk. I employed standard Likert scales and forced-choice questions. I found that: average lying judgments are similar in casual and courtroom contexts; motive to lie decreases trust ascription and increases lying judgment; judgments of lying are inconsistent with previous judgments of communicated content: participants hold the protagonist responsible for content they did not communicate. Perjury ascriptions are inconsistent. The Supreme Court’s worries expressed in the Bronston judgment are well founded. This article helps reforming jury instructions in perjury cases. (shrink)

I explain why, within the nonclassical framework for cognitive science we describe in the book, cognitive-state transitions can fail to be tractably computable even if they are subserved by a discrete dynamical system whose mathematical-state transitions are tractably computable. I distinguish two ways that cognitive processing might conform to programmable rules in which all operations that apply to representation-level structure are primitive, and two corresponding constraints on models of cognition. Although Litch is correct in maintaining that classical cognitive (...) science is not committed to the first constraint, it is committed to the second. This fact constitutes an illuminating gloss on our claim that one foundational assumption of classicism is that human cognition conforms to programmable, representation-level, rules. (shrink)

in UndeterminedInterrogative belief revision is a relatively recent framework for belief revision theory, in which the epistemic state of an agent includes a representation of that agent's research agenda, i.e. the set of questions the agent wants to have answers to. This added structure opens new possibilites for various types of epistemic change that cannot be distinguished in traditional belief revision. In this article I use the so-called 'action model' approach known from the literature on dynamic epistemic logic to (...) provide a unified framework in which we can reason about these various types of epistemic changes. I show how to model some natural examples of epistemic changes involving change of the research agenda in this framework. The action models give rise to a dynamic logic which is proven to be decidable. (shrink)

For the probabilistic description of all the joint von Neumann measurements on a D-dimensional quantum system, we present the specific example of a context-invariant quasi hidden variable model, proved in Loubenets to exist for each Hilbert space. In this model, a quantum observable X is represented by a variety of random variables satisfying the functional condition required in quantum foundations but, in contrast to a contextual model, each of these random variables equivalently models X under all joint von Neumann measurements, (...) regardless of their contexts. This, in particular, implies the specific local qHV model for an N-qudit state and allows us to derive the new exact upper bound on the maximal violation of 2\2-setting Bell-type inequalities of any type under N-partite joint von Neumann measurements on an N-qudit state. For d = 2, this new upper bound coincides with the maximal violation by an N-qubit state of the Mermin–Klyshko inequality. Based on our results, we discuss the conceptual and mathematical advantages of context-invariant and local qHV modelling. (shrink)

Introduction to modelling and validation -- Non-hierarchical coloured petri nets -- CPN ML programming -- Formal definition of non-hierarchical coloured petri nets -- Hierarchical coloured petri nets -- Formal defintion of hierarchical coloured petri nets -- State spaces and behavioural properties -- Advanced state space methods -- Formal definition of state spaces and behavioural properties -- Timed coloured petri nets -- Formal definition of timed coloured petri nets -- Simulation-based performance analysis -- Behavioural visualisation -- Examples of (...) industrial applications -- Teaching coloured petri nets. (shrink)

While genomic and proteomic information describe the overall cellular machinery available to an organism, the metabolic profile of an individual at a given time provides a canvas as to the current physiological state. Concentration levels of relevant metabolites vary under different conditions, in particular, in the presence or absence of different disorders. Metabolite concentrations thus mediate an important link between chemistry and biology, contributing to a systems-wide understanding of biological processes and pathways. However, there are a number of challenges (...) in the ontological representation of such information. Firstly, concentration information is numeric and ranges over continuous values, while ontologies consist of discrete classes. Secondly, ontologies usually model only what is certain, and their logical formalisms are adapted to reasoning from certain axioms to logical deductions, however, the link between chemicals and diseases via concentration levels, like many threshold phenomena, is both uncertain and vague. In this paper we evaluate the representation of this knowledge using a combination of concrete domains and probabilistic reasoning. We parse concentration values from HMDB and create an ontology able to distinguish normal from abnormal concentrations and able to evaluate a probabilistic risk category for the presence of an associated disorder. (shrink)

It was hypothesised that positive affective states and situational information-processing demands would differentially influence the favourability of social judgements of a target social group. These hypothesised direct effects on social judgements were subsequently incorporated into a broader statetrait model of the social judgement process, whereby direct and indirect effects of personality and cognitive traits, along with positive affective states and information-processing demands (i.e. cognitive state), were also hypothesised to influence social judgements. Three hundred and eight subjects reported their trait (...) levels of introversion-extraversion and need for cognition, and were subsequently induced into an affective state (content, happy, surprise, or neutral) and a cognitive state (heuristic or substantive information processing). Results indicated that study participants who were manipulated into either a content or a happy affect state made more positive judgements about the target group than study participants who were manipulated into either a surprised or a neutral state. Moreover, when the cognitive demands of the situation were low, a cognitive trait (need for cognition) and the affective state directly influenced the social judgement. H owever, when the cognitive demands of the situation were high, only an indirect effect of affective state through a cognitive state influenced the social judgement. Discussion focused on the components of the state-trait model of the social judgement process as it applies to positive affective states. (shrink)

Two experiments examined how affective values from visual and auditory modalities are integrated. Experiment 1 paired music and videos drawn from three levels of valence while holding arousal constant. Experiment 2 included a parallel combination of three levels of arousal while holding valence constant. In each experiment, participants rated their affective states after unimodal and multimodal presentations. Experiment 1 revealed a congruency effect in which stimulus combinations of the same extreme valence resulted in more extreme state ratings than component (...) stimuli presented in isolation. An interaction between music and video valence reflected the greater influence of negative affect. Video valence was found to have a significantly greater effect on combined ratings than music valence. The pattern of data was explained by a five parameter differential weight averaging model that attributed greater weight to the visual modality and increased weight with decreasing values of valence. Experiment 2 revealed a congruency effect only for high arousal combinations and no interaction effects. This pattern was explained by a three parameter constant weight averaging model with greater weight for the auditory modality and a very low arousal value for the initial state. These results demonstrate key differences in audiovisual integration between valence and arousal. (shrink)

Utilities of health states are often estimated to support public decisions in health care. People’s preferences may be imprecise, for lack of actual trade-off experience. We show how to elicit the utilities accounting for imprecision, discover the main drivers of imprecision, and compare several approaches to modelling health state utility data in the fuzzy setting. We extended the time trade-off questionnaire, to elicit utilities of states defined in the EQ-5D-3L descriptive system in184 respondents. Our study demonstrates that respondents are (...) capable of assessing their own imprecision and rigorous mathematical modelling is possible. The imprecision is larger than as inferred from the standard TTO method and is larger than estimation error, even in our smallish sample. Non-trading in TTO often results from imprecision, rather than lexicographic preferences for longevity over quality. People are especially imprecise in assessing the impact of usual activities on utility; also, the internal inconsistency of a health state increases the imprecision. Fuzzy least squares method seems best suited to assign disutilities to individual dimensions, while separately modelling the location of utility and amount of imprecision seems best to produce value sets. If crisp parameters are estimated, accounting for imprecision changes the results little. (shrink)

In the last decades of the XX century the world community precisely realized the huge danger of the ecological situation which had been developed on our planet under influence of negative technogenic and other anthropogenous factors. Very complex there were ecological conditions in the territory of the former USSR, including Central Asian region, in particular Uzbekistan, which had experienced all the toughness of the former colonial regime. Understanding the consequences of the ecological catastrophe in the region helps to model sociopolitical (...) and economic activities in the field of preservation of the environment, to realize the fact, that in the system of interstate and interethnic relations the ecological policy should have a priority direction, and its integration, in general,is a modern globalization of international sociopolitical, economic and other relations. Thus, necessity of all-round development of coordination and integration of the ecological policies of the all States of our region, and also near and far abroad. Main principles of interstate ecological relations have been fixed in the declaration of Rio de Janeiro (1992) where it is underlined that “close cooperation and mutual aid of the countries in economic, political, ecological andcultural fields” is necessary, demanding modeling of nature protection actions on a global scale. Principles of integration of the ecological policy which are carried out by the States of the Central Asia, correspond to the regulations of Conference of Rio de Janeiro and equitable to the interests of all people living both inside and outside the region. (shrink)

The concept of social entrepreneurship emerged as a significant factor that contributes toward public welfare and prosperity. Recent studies showed that social entrepreneurship influences the economic growth and sustainability of the state. Therefore, the underlying aim of this study was to investigate the impact of social entrepreneurship on sustainable economic growth and value creation. This study also undertook to observe the mediating role of innovation in the relationship between social entrepreneurship and sustainable economic growth and between social entrepreneurship and (...) value creation. A questionnaire technique was adopted to obtain data from 343 tour operators in China. The Smart-PLS software was used to analyze the data through the aid of a structural equation modelling (SEM) technique. The results revealed that social entrepreneurship has an effect on sustainable economic growth and value creation. The results also demonstrated that innovation has an effect on sustainable economic growth and value creation. Moreover, it was also observed that innovation mediated the relationship between social entrepreneurship and sustainable economic growth and between social entrepreneurship and value creation. Theoretically, this study made a valuable contribution by examining the impact of social entrepreneurship on sustainable economic growth and value creation and innovation as a mediator. In terms of practical implications, this study would certainly aid the policymakers to devise policies and strategies aim to encourage and promote social entrepreneurship. Moreover, future studies can introduce other mediating and moderating variables in order to gain a deeper insight into the phenomenon. (shrink)

Educators are conflicted about whether school provides an appropriate space to teach ethics. Still, they want to develop the moral character of their students, and most of these efforts have used various citizenship values to address our frustration with students’ ‘lack of character’. Recently, a wave of work in the philosophy of education has rejuvenated discussion of Aristotelian virtue ethics, which forms the backbone for programmes that many schools are now adopting. Mark Jonas and Yoshiaki Nakazawa, however, argue that schools (...) should revisit Plato’s pedagogical methods, as well. If educators want to develop virtue in students, they need to understand the mechanism behind moral development. Guided by Plato, they argue that expert teachers use psychological, pedagogical, and philosophical reasoning to induce epiphanies in students, then guide them through virtue-oriented rehabituation. The goal of this article is to explore the legitimacy of Jonas and Nakazawa’s Platonic theory. I begin by describing the state of modern democratic education and its relationship to teaching ethics. I argue that character development is the appropriate route educators should take but that Jonas and Nakazawa’s theory only gives educators a partial understanding of how to do so. They give a plausible model for how our best educators are effective, but we are left wanting a much more robust, instructive picture. I suggest that we need a broader overhaul of the way we view education in a modern democratic society; character development must proceed from a different normative picture of the individual’s place in society. (shrink)

The balance between births and deaths in an age-structured population is strongly influenced by the spatial distribution of sub-populations. Our aim was to describe the demographic process of a fish population in an hierarchical dendritic river network, by taking into account the possible movements of individuals. We tried also to quantify the effect of river network changes (damming or channelling) on the global fish population dynamics. The Salmo trutta life pattern was taken as an example for.We proposed a model which (...) includes the demographic and the migration processes, considering migration fast compared to demography. The population was divided into three age-classes and subdivided into fifteen spatial patches, thus having 45 state variables. Both processes were described by means of constant transfer coefficients, so we were dealing with a linear system of difference equations. The discrete case of the variable aggregation method allowed the study of the system through the dominant elements of a much simpler linear system with only three global variables: the total number of individuals in each age-class. (shrink)

Observability is a modelling property that describes the possibility of inferring the internal state of a system from observations of its output. A related property, structural identifiability, refers to the theoretical possibility of determining the parameter values from the output. In fact, structural identifiability becomes a particular case of observability if the parameters are considered as constant state variables. It is possible to simultaneously analyse the observability and structural identifiability of a model using the conceptual tools of differential (...) geometry. Many complex biological processes can be described by systems of nonlinear ordinary differential equations and can therefore be analysed with this approach. The purpose of this review article is threefold: to serve as a tutorial on observability and structural identifiability of nonlinear systems, using the differential geometry approach for their analysis; to review recent advances in the field; and to identify open problems and suggest new avenues for research in this area. (shrink)

In fear differential conditioning, stimuli that resemble the conditioned stimulus (CS+) are more likely to trigger fear responses. Excessive fear responses on stimuli not like CS + are often associated with anxiety. However, the threat judgments process and how this process manifests itself differently in subgroups with different generalisation rule applications, is unclear. This study examines whether anxiety biases the threat decision process in fear generalisation paradigm and whether subgroups characterised by different generalisation gradients was interpreted differently by drift-diffusion model. (...) We gathered behavioural data through a binary fear generalisation judgment task and clustered participants based on their responses. Reaction time distributions and individual scale scores were analyzed using the hierarchical drift-diffusion model. The model results suggested that similarity and state anxiety facilitated evidence-gathering processes that favoured “threat” judgments, but at the same time, state anxiety weakened the effect of stimulus similarity as evidence. Further cluster analyses revealed that this effect of anxiety on threat judgments only held true for specific subgroups of participants. This pioneering computational modelling effort in fear generalisation underscores the significant role of strategy preference and its complex interaction with anxiety in shaping stimulus processing. (shrink)

Heterogenous flows across system boundaries continue to pose significant problems for efficient resource allocation especially with respect to long term strategic planning and immediate problems about allocation to address particular resource shortages. The approach taken here to modelling such flows is an engineering change prediction one. This enables margin modelling by producing system models in dependency matrices with different linkage types. Change prediction approaches from engineering design can analyse where these bottlenecks in integrated systems would be so that resources can (...) be deployed flexibility to avoid them and address them when they occur. Current state of the art of margin research can be furthered by identifying margins on multiple levels of system composition. It can usefully be complemented by a category theory based approach which allows representation of variable and constant properties of models under changing conditions, and the identification of flows within models. Category theory is useful for formalising such explanatory frameworks as it can both structure systems and permit analysis of their applications in a complementary way. (shrink)

The goal of cognitive modeling is to build faithful simulations of human cognition. One of the challenges is that multiple models can often explain the same phenomena. Another challenge is that models are often very hard to understand, explore, and reuse by others. We discuss some of the solutions that were discussed during the 2015 International Conference on Cognitive Modeling.

I argue that uniquely human forms of ‘Theory of Mind’ are a product of cultural evolution. Specifically, propositional attitude psychology is a linguistically constructed folk model of the human mind, invented by our ancestors for a range of tasks and refined over successive generations of users. The construction of these folk models gave humans new tools for thinking and reasoning about mental states—and so imbued us with abilities not shared by non-linguistic species. I also argue that uniquely human forms of (...) ToM are not required for language development, such that an account of the cultural origins of ToM does not jeopardise the explanation of language development. Finally, I sketch a historical model of the cultural evolution of mental state talk. (shrink)

The current article aims to provide an up-to-date synopsis of available techniques to study affect dynamics using intensive longitudinal data (ILD). We do so by introducing the following eight dichotomies that help elucidate what kind of data one has, what process aspects are of interest, and what research questions are being considered: (1) single- versus multiple-person data; (2) univariate versus multivariate models; (3) stationary versus nonstationary models; (4) linear versus nonlinear models; (5) discrete time versus continuous time models; (6) discrete (...) versus continuous variables; (7) time versus frequency domain; and (8) modeling the process versus computing descriptives. In addition, we discuss what we believe to be the most urging future challenges regarding the modeling of affect dynamics. (shrink)

A person's cognitive map, or knowledge of large‐scale space, is built up from observations gathered as he travels through the environment. It acts as a problem solver to find routes and relative positions, as well as describing the current location. The TOUR model captures the multiple representations that make up the cognitive map, the problem‐solving strategies it uses, and the mechanisms for assimilating new information. The representations have rich collections of states of partial knowledge, which support many of the performance (...) characteristics of common‐sense knowledge. (shrink)

The goal of cognitive modeling is to build faithful simulations of human cognition. One of the challenges is that multiple models can often explain the same phenomena. Another challenge is that models are often very hard to understand, explore, and reuse by others. We discuss some of the solutions that were discussed during the 2015 International Conference on Cognitive Modeling.

In this paper we describe a method for the specification of computationalmodels of argument using dialogue games. The method, which consists ofsupplying a set of semantic definitions for the performatives making upthe game, together with a state transition diagram, is described in full.Its use is illustrated by some examples of varying complexity, includingtwo complete specifications of particular dialogue games, Mackenzie's DC,and the authors' own TDG. The latter is also illustrated by a fully workedexample illustrating all the features of the (...) game. (shrink)

Cognitive modeling is the effort to understand the mind by implementing theories of the mind in computer code, producing measures comparable to human behavior and mental activity. The community of cognitive modelers has traditionally met twice every 3 years at the International Conference on Cognitive Modeling. In this special issue of topiCS, we present the best papers from the ICCM meeting. These best papers represent advances in the state of the art in cognitive modeling. Since ICCM (...) was for the first time also held jointly with the Society for Mathematical Psychology, we use this preface to also reflect on the similarities and differences between mathematical psychology and cognitive modeling. (shrink)

Behavior oftentimes allows for many possible interpretations in terms of mental states, such as goals, beliefs, desires, and intentions. Reasoning about the relation between behavior and mental states is therefore considered to be an effortful process. We argue that people use simple strategies to deal with high cognitive demands of mental state inference. To test this hypothesis, we developed a computational cognitive model, which was able to simulate previous empirical findings: In two-player games, people apply simple strategies at first. (...) They only start revising their strategies when these do not pay off. The model could simulate these findings by recursively attributing its own problem solving skills to the other player, thus increasing the complexity of its own inferences. The model was validated by means of a comparison with findings from a developmental study in which the children demonstrated similar strategic developments. (shrink)

Real-world economies are open-ended dynamic systems consisting of heterogeneous interacting participants. Human participants are decision-makers who strategically take into account the past actions and potential future actions of other participants. All participants are forced to be locally constructive, meaning their actions at any given time must be based on their local states; and participant actions at any given time affect future local states. Taken together, these essential properties imply real-world economies are locally-constructive sequential games. This paper discusses a modeling (...) approach, Agent-based Computational Economics, that permits researchers to study economic systems from this point of view. ACE modeling principles and objectives are first concisely presented and explained. The remainder of the paper then highlights challenging issues and edgier explorations that ACE researchers are currently pursuing. (shrink)

In this paper we look at the manual analysis of arguments and how this compares to the current state of automatic argument analysis. These considerations are used to develop a new approach combining a machine learning algorithm to extract propositions from text, with a topic model to determine argument structure. The results of this method are compared to a manual analysis.

In this paper we present the syntax and semantics of a temporal action language named Alan, which was designed to model interactive multimedia presentations where the Markov property does not always hold. In general, Alan allows the specification of systems where the future state of the world depends not only on the current state, but also on the past states of the world. To the best of our knowledge, Alan is the first action language which incorporates causality with (...) temporal formulas. In the process of defining the effect of actions we define the closure with respect to a path rather than to a state, and show that the non-Markovian model is an extension of the traditional Markovian model. Finally, we establish relationship between theories of Alan and logic programs. (shrink)

Although the body of literature in sport science is growing rapidly, certain sports have yet to benefit from this increased interest by the scientific community. One such sport is Ultimate Frisbee, officially known as Ultimate. Thus, the goal of this study was to describe the nature of the sport by identifying differences between winning and losing teams in elite-level competition. To do so, a customized observational system and a state transition model were developed and applied to 14 games from (...) the 2017 American Ultimate Disc League season. The results reveal that, on average, 262.2 passes were completed by a team per game and 5.5 passes per possession. More than two-thirds of these passes were played from the mid zone and the rear zone, nearest the team’s own end zone. Winning and losing teams do not differ in these general patterns, but winning teams played significantly fewer backward passes from the front zone to the mid zone, nearest the opponent’s end zone than losing teams = −4.980, p < 0.001, d = −1.16). Furthermore, losing teams scored fewer points when they started on defense, called breakpoints = −6.365, p < 0.001, d = 2.30), and committed significantly more turnovers per game = 5.85, p < 0.001, d = −1.18). Overall, this study provides the first empirical description of Ultimate and identifies relevant performance indicators to discriminate between winning and losing teams. We hope this article sheds light on the unique, but so far overlooked sport of Ultimate, and offers performance analysts the basis for future studies using state transition modeling in Ultimate as well as other invasion sports. (shrink)

Unlike inert objects, organisms and their cells have the ability to initiate activity by themselves and thus change their properties or states even in the absence of an external cause. This crucial difference led us to search for principles suitable for the study organisms. We propose that cells follow the default state of proliferation with variation and motility, a principle of biological inertia. This means that in the presence of sufficient nutrients, cells will express their default state. We (...) also propose a principle of variation that addresses two central features of organisms, variation and historicity. To address interdependence between parts, we use a third principle, the principle of organization, more specifically, the notion of the closure of constraints. Within this theoretical framework, constraints are specific theoretical entities defined by their relative stability with respect to the processes they constrain. Constraints are mutually dependent in an organized system and act on the default state.Here we discuss the application and articulation of these principles for mathematical modeling of morphogenesis in a specific case, that of mammary ductal morphogenesis, with an emphasis on the default state. Our model has both a biological component, the cells, and a physical component, the matrix that contains collagen fibers. Cells are agents that move and proliferate unless constrained; they exert mechanical forces that act (i) on collagen fibers and (ii) on other cells. As fibers are organized, they constrain the cells’ ability to move and to proliferate. This model exhibits a circularity that can be interpreted in terms of the closure of constraints. Implementing our mathematical model shows that constraints to the default state are sufficient to explain the formation of mammary epithelial structures. Finally, the success of this modeling effort suggests a stepwise approach whereby additional constraints imposed by the tissue and the organism can be examined in silico and rigorously tested by in vitro and in vivo experiments, in accordance with the organicist perspective we embrace. (shrink)

In this issue of topiCS, we present the best papers from the ICCM meeting. These best papers represent advances in the state of the art in cognitive modeling. Since ICCM was for the first time also held jointly with the Society for Mathematical Psychology, we use this preface to also reflect on the similarities and differences between mathematical psychology and cognitive modeling.

Biological modalities, i.e., biologically possible, impossible, or necessary states of affairs have not received much attention from philosophers. Yet, it is widely agreed that there are biological constraints on physically possible states of affairs, such that not everything that is physically possible is also biologically possible, even if everything that is biologically possible is also physically possible. Furthermore, biologists use concepts that appear to be modal in nature, such as the concept of evolvability in evolutionary developmental biology, or “evo-devo.” The (...) present chapter investigates what kind of modality underlies the concept of evolvability. This concept tries to capture the capacity of an organism or a lineage to sustain genetic changes that enable it to evolve or to evolve adaptively. The basic idea of the proposed approach is to construe evolvability as a kind of accessibility in a modal space. The difficult part is to specify this modal space and the relevant accessibility relation. While there may not be a general way of defining such a relation, there exist model systems for which it is possible, e.g., evolving small RNAs. The modal space in such cases turns out to be quite distinct from those constructed by philosophers, e.g., David Lewis’s similarity metric for possible worlds. Even though the biological case examined here is quite special, attending to the way in which biological possibilities are modeled in this case harbors some general lessons about biological modalities, in particular their dependence on the explanatory goals of the models modeling modality. (shrink)

The following list contains a survey of some important and recent research in modeling face-to-face conversation. The list below is a presented as a guide to the literature by topic and date; we include complete citations afterwards in alphabetical order. For brevity, research works are keyed by first author and date only (we use these keys on the slides as well as in this list). Of course, most papers are multiply authored. The list is not intended to be exhaustive. (...) Our primary aim is simply to provide bibliographic information for all the research that we will refer to during the ESSLLI class itself. The entries also provide a sampling from ongoing research projects so that you can get an overall sense of the state of the field and begin to follow up topics of particular interest to you. (shrink)

This Article considers the conditions under which administrative agencies - particularly those with public health-related missions - may obtain partial autonomy from external interests or politicians. In the process, it critiques the proposition that administrative agencies in advanced industrialized countries such as the United States are routinely “captured” by external economic interests. Through case studies and the application of relevant theory from law and the study of political organization, the Article describes how agencies can produce a measure of autonomy by (...) forging coalitions of stakeholders both internal and external to the agency, and considers how partial autonomy may be modeled as a strategic process involving decisions under uncertainty. The Article then investigates how American publichealth agencies such as the Food and Drug Administration, the Food Safety Inspection Service, and the Centers for Disease Control have been able to use their partial autonomy to develop significant health policy innovations. Although agencies are by no means guaranteed even a partial degree of autonomy, they are nonetheless capable of affecting their political and legal environment, with consequences not only for public-health policy but also for the legitimacy of the nation-state. (shrink)

The fundamental relations in private law are claims and duties. These legal relations can be changed by agents with the appropriate legal powers. We use propositional dynamic logic and ideas about propositional control from the agency literature to formalize these changes in legal relations. Our models are sets of states with functions specifying atomic facts, agents’ abilities to change atomic facts, legal relations between agents concerning changing atomic facts and agents’ powers. We present a formal language that allows us to (...) describe models and changes of models caused by two kinds of actions: actions that change atomic facts and actions that change legal relations. Next, we present a sound and complete calculus for this language. The paper demonstrates that the perspective on actions borrowed from computer science can be used to shed interesting light on the dynamics of legal relations. (shrink)

Pluripotency can be considered a functional characteristic of pluripotent stem cells (PSCs) populations and their niches, rather than a property of individual cells. In this view, individual cells within the population independently adopt a variety of different expression states, maintained by different signaling, transcriptional, and epigenetics regulatory networks. In this review, we propose that generation of integrative network models from single cell data will be essential for getting a better understanding of the regulation of self‐renewal and differentiation. In particular, we (...) suggest that the identification of network stability determinants in these integrative models will provide important insights into the mechanisms mediating the transduction of signals from the niche, and how these signals can trigger differentiation. In this regard, the differential use of these stability determinants in subpopulation‐specific regulatory networks would mediate differentiation into different cell fates. We suggest that this approach could offer a promising avenue for the development of novel strategies for increasing the efficiency and fidelity of differentiation, which could have a strong impact on regenerative medicine. (shrink)

In this work, we study and analyze the aggregate death counts of COVID-19 reported by the United States Centers for Disease Control and Prevention (CDC) for the fifty states in the United States. To do this, we derive a stochastic model describing the cumulative number of deaths reported daily by CDC from the first time Covid-19 death is recorded to June 20, 2021 in the United States, and provide a forecast for the death cases. The stochastic model derived in this (...) work performs better than existing deterministic logistic models because it is able to capture irregularities in the sample path of the aggregate death counts. The probability distribution of the aggregate death counts is derived, analyzed, and used to estimate the count’s per capita initial growth rate, carrying capacity, and the expected value for each given day as at the time this research is conducted. Using this distribution, we estimate the expected first passage time when the aggregate death count is slowing down. Our result shows that the expected aggregate death count is slowing down in all states as at the time this analysis is conducted (June 2021). A formula for predicting the end of Covid-19 deaths is derived. The daily expected death count for each states is plotted as a function of time. The probability density function for the current day, together with the forecast and its confidence interval for the next four days, and the root mean square error for our simulation results are estimated. (shrink)

While speakers have been shown to adapt to the knowledge state of their addressee in choosing referring expressions, they often also show some egocentric tendencies. The current paper aims to provide an explanation for this “mixed” behavior by presenting a model that derives such patterns from the probabilistic combination of both the speaker's and the addressee's perspectives. To test our model, we conducted a language production experiment, in which participants had to refer to objects in a context that also (...) included a visually misleading object whose function was either known to both partners, or known just to the speaker but not the addressee. Modeling results indicate that the experimental findings cannot be explained by assuming that speakers tailor a referring expression solely to their own perspective or to the perspective of their addressee. Instead, accounting for the behavioral pattern requires an approach where both perspectives influence the choice of referring expressions. Nevertheless, in our situation, speakers consider their partner's perspective more than their own. (shrink)

A computational model of inference during story comprehension is presented, in which story situations are represented distributively as points in a high‐dimensional “situation‐state space.” This state space organizes itself on the basis of a constructed microworld description. From the same description, causal/temporal world knowledge is extracted. The distributed representation of story situations is more flexible than Golden and Rumelhart's [Discourse Proc 16 (1993) 203] localist representation.A story taking place in the microworld corresponds to a trajectory through situation‐state (...) space. During the inference process, world knowledge is applied to the story trajectory. This results in an adjusted trajectory, reflecting the inference of propositions that are likely to be the case. Although inferences do not result from a search for coherence, they do cause story coherence to increase. The results of simulations correspond to empirical data concerning inference, reading time, and depth of processing.An extension of the model for simulating story retention shows how coherence is preserved during retention without controlling the retention process. Simulation results correspond to empirical data concerning story recall and intrusion. (shrink)

The emphasis on models hasn’t completely eliminated laws from scientific discourse and philosophical discussion. Instead, I want to argue that much of physics lies beyond the strict domain of laws. I shall argue that in important cases the physics, or physical understanding, does not lie either in laws or in their properties, such as universality, consistency and symmetry. I shall argue that the domain of application commonly attributed to laws is too narrow. That is, laws can still play an important, (...) though peculiar, role outside their strict domain of validity. I shall argue also that, by way of a trade-off, while the actual domain of application of laws should be seen as much broader. At the same time, what I call ‘anomic’ representational elements reveal themselves as central to the descriptive and explanatory power of theories and model: boundary conditions, state descriptions, structures, constraints, limits and mechanisms. I conclude with a brief consideration of how my discussion has consequences for discussion of understanding, unification, approximation and dispositional properties. I focus on examples from physics, macroscopic and microscopic, phenomenological and fundametal: shock waves, propagation of cracks, symmetry breaking, and others. This law-eccentric kind of knowledge is central to both modeling the world and intervening in it. (shrink)