On returns and network configuration in supply chain dynamics

This research focuses on how two common modeling assumptions in the Bullwhip Effect (BWE) literature (i.e., assuming the return of the excess of goods and assuming a serial network) may distort the results obtained. We perform a robust design of experiments where the return condition (return vs. no return) and the configuration of the Supply Chain Network (SCN) (serial vs. divergent) are systematically analyzed. We find an important interaction between these assumptions: the impact of returns on the BWE strongly depends on the SCN configuration. This study highlights the importance of accurately modeling SCNs to properly assess SCNs managers.Junta de Andalucía P08-TEP-0363

Dephasing and leakage dynamics of noisy Majorana-based qubits: Topological versus Andreev

Topological quantum computation encodes quantum information nonlocally by nucleating non-Abelian anyons separated by distances L, typically spanning the qubit device size. This nonlocality renders topological qubits exponentially immune to dephasing from all sources of classical noise with operator support local on the scale of L. We perform detailed analytical and numerical analyses of a time-domain Ramsey-type protocol for noisy Majorana-based qubits that is designed to validate this coveted topological protection in near-term devices such as the so-called “tetron” design. By assessing dependence of dephasing times on tunable parameters, e.g., magnetic field, our proposed protocol can clearly distinguish a bona fide Majorana qubit from one constructed from semilocal Andreev bound states, which can otherwise closely mimic the true topological scenario in local probes. In addition, we analyze leakage of the qubit out of its low-energy manifold due to classical-noise-induced generation of quasiparticle excitations; leakage limits the qubit lifetime when the bulk gap collapses, and hence our protocol further reveals the onset of a topological phase transition. This experiment requires measurement of two nearby Majorana modes for both initialization and readout—achievable, for example, by tunnel coupling to a nearby quantum dot—but no further Majorana manipulations, and thus constitutes an enticing prebraiding experiment. Along the way, we address conceptual subtleties encountered when discussing dephasing and leakage in the context of Majorana qubits

Social dynamics from the bottom up:Agent-based models of social interaction

This article focuses on agent-based computational (ABC) modeling of social interaction. It begins with an overview of ABC modeling as a computational implementation of ‘methodological individualism’, the search for the microfoundations of social life in the actions of intentional agents. It then considers how the ABC method differs from an earlier generation of modeling approaches, including game theory, equation-based models of computer simulation (such as system dynamics), and multivariate linear models. It also discusses potential weaknesses of ABC modeling and proposes research strategies to address them. The article suggests that ABC modeling will lead to significant advances in the bottom-up approach to the study of social dynamics.</p

Specifying and Exploiting Non-Monotonic Domain-Specific Declarative Heuristics in Answer Set Programming

Domain-specific heuristics are an essential technique for solving combinatorial problems efficiently. Current approaches to integrate domain-specific heuristics with Answer Set Programming (ASP) are unsatisfactory when dealing with heuristics that are specified non-monotonically on the basis of partial assignments. Such heuristics frequently occur in practice, for example, when picking an item that has not yet been placed in bin packing. Therefore, we present novel syntax and semantics for declarative specifications of domain-specific heuristics in ASP. Our approach supports heuristic statements that depend on the partial assignment maintained during solving, which has not been possible before. We provide an implementation in ALPHA that makes ALPHA the first lazy-grounding ASP system to support declaratively specified domain-specific heuristics. Two practical example domains are used to demonstrate the benefits of our proposal. Additionally, we use our approach to implement informed} search with A*, which is tackled within ASP for the first time. A* is applied to two further search problems. The experiments confirm that combining lazy-grounding ASP solving and our novel heuristics can be vital for solving industrial-size problems

Topics in social network analysis and network science

This chapter introduces statistical methods used in the analysis of social networks and in the rapidly evolving parallel-field of network science. Although several instances of social network analysis in health services research have appeared recently, the majority involve only the most basic methods and thus scratch the surface of what might be accomplished. Cutting-edge methods using relevant examples and illustrations in health services research are provided

Dimensions of Accountability in Inter-organizational Business Processes

Inter-organizational business processes are the basis of a globalized, highly dynamic, and digitalized world, en-abling faster and cost-effective transactions. At the same time, they raise business vulnerabilities. A partic-ular vulnerability is linked to the substantiation of trust between actors in dynamic business relationships, as trust affects interdependencies and complexity. An ap-proach to address this vulnerability is the introduction of accountability mechanisms. Extant research suggests that accountability enables revealing causality and a transparent allocation of responsibilities for each pro-cess step. Thereby, corresponding actors can judge upon misbehavior and verify trust claims. Unfortu-nately, a thorough understanding of accountability and its dimensions accountability in the context of IBP is still missing. To address this gap, we develop a framework with dimensions of accountability. We demonstrate the resulting framework in an industrial supply chain case and derive implications for theory and practice

Predictive processing and cognitive development

The ability to acquire new cognitive capacities is the hallmark of the human mind. Emerging predictive processing (PP) accounts promise to offer a unified, mechanistic perspective on the neuro-functional realization of this complex process. The acquisition of any given cognitive capacity can be depicted as a specific stage of the continuous prediction error minimization process. This stage is characterized by distinct functional profiles, unique patterns of neuronal activation in crucial brain areas, and the refinement and flexible adaptation of motor programs to new processing challenges. In this paper, I will suggest that PP is a good conceptual partner for accounts of enculturation. Enculturation is the idea that socio-culturally shaped cognitive processes emerge from an individual’s scaffolded, embodied interaction with its cognitive niche. This structured engagement with specific, socio-culturally developed patterns in the niche transforms the overall cognitive capacities of an individual (Menary 2013; Menary 2015). The process of enculturation is associated with significant changes in the functional and structural properties of the brain. Furthermore, it alters and refines the functional profiles of bodily actions and motor programs. I will argue that PP offers important conceptual tools and theoretical considerations that complement these basic principles of enculturation in a new and original way. The resulting account of the enculturated predictive acquisition of cognitive capacities (EPACC) has the conceptual resources to consider specific cases of cognitive development at multiple levels of explanation. This new perspective on EPACC is a timely contribution to the debate about the philosophical implications of PP. On the one hand, Jakob Hohwy (Hohwy 2013) argues that PP implies an internalistic and neurocentric view of cognition. On his account, the embodiedness of cognitive systems and their flexible interaction with the local environment do not seem to play an important role in accounts of cognitive processes. On the other hand, Andy Clark (Clark 2016) defends the idea that PP is compatible with philosophical positions that emphasize the embodied, embedded, extended, or enacted (4E) dimensions of cognition. In this paper, I will discuss both interpretations of PP and assess their relationship to EPACC. I will challenge the internalistic account of PP on conceptual grounds. At the same time, I will argue that EPACC offers a concrete proposal for the complementarity of PP and enculturation. The overall argument is that the acquisition of new, socio-culturally shaped cognitive capacities is a matter of enculturation. The underlying neuronal and bodily transformation routines can be described in terms of PP. However, if we aim for a full-fledged account of the complexity and fragility of cognitive development, we also need an account of the fine-grained interactions of novices with their structured environment