Poisson algebras for non-linear field theories in the Cahiers topos

We develop an approach to construct Poisson algebras for non-linear scalar field theories that is based on the Cahiers topos model for synthetic differential geometry. In this framework the solution space of the field equation carries a natural smooth structure and, following Zuckerman's ideas, we can endow it with a presymplectic current. We formulate the Hamiltonian vector field equation in this setting and show that it selects a family of observables which forms a Poisson algebra. Our approach provides a clean splitting between geometric and algebraic aspects of the construction of a Poisson algebra, which are sufficient to guarantee existence, and analytical aspects that are crucial to analyze its properties

Qualitative evaluation of a physical activity-based chronic disease prevention program in a low-income, rural South African setting

Introduction: Chronic diseases, an increasing global concern, are prevalent in the low-income communities of South Africa, where rural health systems bear the double burden of infectious and chronic diseases. The Discovery Healthy Lifestyle Programme (DHLP) is a physical activity-based chronic disease prevention program that has been implemented in a low-income, rural setting in South Africa. The DHLP consists of both school- and primary healthcare clinic-based interventions for learners (Healthnutz) and adults (Live it Up), facilitated by teachers, nurses and community volunteers. The aim of this evaluation was to qualitatively assess the process by which the DHLP was implemented, identifying enabling factors and barriers. Methods: Data were collected in target communities at schools and clinics from semi-structured focus groups of program leaders and members, teachers and community members (n=45), situational analyses of the school physical activity environment, informal community observations and informal interviews with program coordinators. Results: The target communities faced socioeconomic and health inequalities and remained under-resourced and under-served. In spite of these and other challenges, the DHLP was well received by community members and stakeholders. It was valued by respondents for its health and psychosocial outcomes, evidenced by increased knowledge and awareness of the importance of physical activity and healthy lifestyles, and positively altered perceptions of physical activity. Program implementers believed the Live it Up component was growing, and this suggested the sustainability of the program. There were, however, some concerns about the fidelity of the Healthnutz intervention, due to timetabling difficulties. Despite this, teachers were positive about the program and its value for their learners, staff and school. The community characteristics of being under-resourced and underserved appeared to positively influence DHLP implementation. Local government involvement in the DHLP resulted in greater ownership of the program, which enabled successful implementation. Conclusions: This study presents a unique opportunity to assess the implementation and sustainability requirements of programs in environments of limited resources, considerable burden of infectious and chronic diseases and extensive socioeconomic challenges. The findings suggest that through enhancement of knowledge, transfer of appropriate skills and the provision of an enabling environment, participation in physical activity can be effectively promoted in a low-income, rural setting. Physical activity interventions that promote the participation and empowerment of rural communities can be feasible and accessible, thereby assisting in addressing the growing burden of chronic diseases in low-income

Project Lineage Management and Project Portfolio Success

Project portfolio approaches consider various concurrent project interdependencies but typically neglect longitudinal interdependencies. These are important for exploratory projects, which create strategic options. If these options are not exploited in successive projects they become lost opportunities. This study analyzes 138 firms regarding their extent to consciously manage project sequences. We differentiate between proactive lineage (planning a roadmap of future projects) and reactive lineage (using learnings from past projects). Results show that both practices are positively and independently related to portfolio success. We derive suggestions for future research and discuss which theoretical foundations could be used to better understand the impact of lineage management.acceptedVersio

Distant and Local Knowledge: Investigating the Effect of Changing Interest in Knowledge Generation

This study examines how changes between drawing inspiration from distant knowledge and focusing on local knowledge affect contributions in online communities. The research compares two theoretical frameworks for understanding knowledge generation: The tension-based view highlights the tensional perspective of initially engaging with distant knowledge before narrowing the focus to specific domains to foster creative behavior. Conversely, the foundational view posits that creative behavior requires local expertise before it is combined with insights from distant knowledge domains. We collected data from 15 Q&A forums hosted by Stack Exchange and used natural language processing to analyze users’ contributions and changes in interest. Our findings suggest that both theories explain knowledge generation. Individuals need to engage with more distant knowledge over time but also streamline their interests between local and distant knowledge domains to generate more valuable and novel contributions. The study enriches understanding of knowledge generatio

A Dual Process Approach to Understand Tourists’ Destination Choice Processes

Most studies that investigate tourists\u27 choices of destinations apply the concept of mental destination representations, also referred to as destination image. The present study investigates tourists’ destination choice processes by conceptualizing how different components of destination image are mentally processed in tourists\u27 minds. Specifically, the seminal dual processing approach is applied to the destination image literature. By doing this, we argue that some components of mental destination representations are processed systematically while others serve as inputs for heuristics that individuals apply to inform their decision making. Understanding how individuals make use of their mental destination representations and how they color their decision-making is essential in order to better explain tourist behavior

Experimental-numerical approach to efficient TTT-generation for simulation of phase transformations in thermomechanical forming processes

Residual stresses in components are an important issue in most manufacturing processes, as they influence the performance of the final part. Regarding hot forming processes there is a great potential of defining a targeted residual stress state, due to numerous adjustment parameters like deformation state or temperature profile. In order to ensure appropriate numerical modelling of resulting residual stresses in a thermomechanical process, comprehensive material data regarding phase transformation are required. This paper presents an experimental-numerical procedure to efficiently determine time-temperature-transformation diagrams for cooling simulations after hot forming. The transformation behaviour of the steel alloys 42CrMo4 and 100Cr6 is determined by experiments as well as FE-simulations. Finally, the simulation model is validated by dilatometric experiments and metallographic investigations

The project-oriented organization and its contribution to innovation

This paper presents a new conceptualization of the project-oriented organization. The project-oriented organization is conceptualized as an entrepreneurial, future- and stakeholder-oriented innovating organization, which uses projects as temporary, task-focused organizations, to define, develop, and implement its strategies, to transform its structure, culture and behavior, and to define and develop new products, services, and business models. The concept of the project-oriented organization consists of the three segments (1) values, (2) structures, and (3) people. For each segment three important areas are described, which characterize a project-oriented organization. The model is theoretically based on a wide spectrum of management disciplines: (1) The orientations in the value segment have been developed in entrepreneurship, strategic management and technology and innovation management; (2) The foundations for the design of the socio-technical artefacts in the structure segment of derived from organizational design, planning and controlling, and ICT systems theory; (3) The foundations for the elements of the human side come from organizational behavior, human resource management, and knowledge management theories. Our model shows a clear linkage to these theories, references key articles, and gives special consideration to empirical studies in the realm of projects, programs, project portfolios, and project-based or project-oriented organizations. Thus, our assumption that the elements of our model are supposed to increase project success, innovation success, and business success is based on empirical evidence.acceptedVersion1, forfatterversjo

Cauchy's infinitesimals, his sum theorem, and foundational paradigms

Cauchy's sum theorem is a prototype of what is today a basic result on the convergence of a series of functions in undergraduate analysis. We seek to interpret Cauchy's proof, and discuss the related epistemological questions involved in comparing distinct interpretive paradigms. Cauchy's proof is often interpreted in the modern framework of a Weierstrassian paradigm. We analyze Cauchy's proof closely and show that it finds closer proxies in a different modern framework. Keywords: Cauchy's infinitesimal; sum theorem; quantifier alternation; uniform convergence; foundational paradigms.Comment: 42 pages; to appear in Foundations of Scienc

Identifying User Innovations through AI in Online Communities– A Transfer Learning Approach

Identifying innovative users and their ideas is crucial, for example, in crowdsourcing. But, analyzing large amounts of unstructured textual data from such online communities poses a challenge for organizations. Therefore, researchers started developing automated approaches to identify innovative users. Our study introduces an advanced machine-learning approach that minimizes manual work by combining transfer learning with a transformer-based design. We train the model on separate datasets, including an online maker community and various internet texts. The maker community posts represent need-solution pairs, which express needs and describe fitting prototypes. Then, we transfer the model and identify potential user innovations in a kitesurfing community. We validate the identified posts by manually checking a subsample and analyzing how words affect the model\u27s classification decision. This study contributes to the growing portfolio of user innovation identification by combining state-of-the-art natural language processing and transfer learning to improve automated identification

Modular Design of KEM-Based Authenticated Key Exchange

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