Automated Equation Formulation for Causal Loop Diagrams

The annotation of Business Dynamics models with parameters and equations, to simulate the system under study and further evaluate its simulation output, typically involves a lot of manual work. In this paper we present an approach for automated equation formulation of a given Causal Loop Diagram (CLD) and a set of associated time series with the help of neural network evolution (NEvo). NEvo enables the automated retrieval of surrogate equations for each quantity in the given CLD, hence it produces a fully annotated CLD that can be used for later simulations to predict future KPI development. In the end of the paper, we provide a detailed evaluation of NEvo on a business use-case to demonstrate its single step prediction capabilities.

Analysis of a controversial decision process: the case of the pumped hydro storage power plant Atdorf in Germany

Based on the report for the unit “Métodos Interactivos de Participação e Decisão A” (Interactive methods of participation and decision A), coordinated by Prof. Lia Maldonado Teles de Vasconcelos and Prof. Nuno Miguel Ribeiro Videira Costa. This unit was provided for the PhD Program in Technology Assessment in 2015/2016.

Modeling Of Work-Related Musculoskeletal Disorders In Chemical Process Industry In India

In this modern complex world, stress at work is found to be increasingly a common feature in day to day life. For the same reason, job stress is one of the active areas in occupational health and safety research for over last four decades and is continuing to attract researchers in academia and industry. Job stress in process industries is of concern due to its influence on process safety, and worker‘s safety and health. Safety in process (chemical and nuclear material) industry is of paramount importance, especially in a thickly populated country like India. Stress at job is the main vector in inducing work related musculoskeletal disorders which in turn can affect the worker health and safety in process industries. In view of the above, the process industries should try to minimize the job stress in workers to ensure a safe and healthy working climate for the industry and the worker. This research is mainly aimed at assessing the influence of job stress in inducing work related musculoskeletal disorders in chemical process industries in India

NDIM achievements: massive, arbitrary tensor rank and N-loop insertions in Feynman integrals

One of the main difficulties in studying quantum field theory, in the perturbative regime, is the calculation of D-dimensional Feynman integrals. In general, one introduces the so-called Feynman parameters and, associated with them, the cumbersome parametric integrals. Solving these integrals beyond the one-loop level can be a difficult task. The negative-dimensional integration method (NDIM) is a technique whereby such a problem is dramatically reduced. We present the calculation of two-loop integrals in three different cases: scalar ones with three different masses, massless with arbitrary tensor rank, with and N insertions of a two-loop diagram.

Two-Point Function at Two Loops via Triangle Diagram Insertion

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

All one-loop scalar vertices in the effective potential approach

Using the one-loop Coleman-Weinberg effective potential, we derive a general analytic expression for all the derivatives of the effective potential with respect to any number of classical scalar fields. The result is valid for a renormalisable theory in four dimensions with any number of scalars, fermions or gauge bosons. This result corresponds to the zero-external momentum contribution to a general one-loop diagram with N scalar external legs. We illustrate the use of the general result in two simple scalar singlet extensions of the Standard Model, to obtain the dominant contributions to the triple couplings of light scalar particles under the zero external momentum approximation.

Gestión de la cadena de suministros desde la dinámica de sistemas. Aproximación al mejoramiento de la toma de decisiones

El objetivo de este trabajo es hacer un estudio sobre la cadena de suministros en organizaciones empresariales desde la Dinámica de Sistemas y como esta puede aportar al desempeño y el control de las cadenas de suministros. Se buscará Abordar el cocimiento sobre tres perspectivas de Supply Chain y su relación con la dinámica de sistemas. También se buscará identificar los tipos de integración en las actividades de la gestión en la cadena de suministros y sus horizontes de planeación. Por último, se pretende analizar las aplicaciones de Supply Chain Management que se han basado en el uso de la metodología de dinámica de sistemas. Para esto, la investigación empezará por definir la problemática alrededor de unir estas dos áreas y definirá el marco teórico que fundan estas dos disciplinas. Luego se abordará la metodología usada por la Dinámica de Sistemas y los diferentes aspectos de la cadena de suministros. Se Ahondará en el acercamiento de las dos disciplinas y como convergen ayudando la SD a la SCM (Supply Chain Management). En este punto también se describirán los trabajos en los diferentes enfoques que se han hecho a partir de uso de la dinámica de sistemas. Por último, presentaremos las correspondientes conclusiones y comentarios acerca de este campo de investigación y su pertinencia en el campo de la Supply Chain. Esta investigación abarca dos grandes corrientes de pensamiento, una sistémica, a través de la metodología de dinámica de sistemas y la otra, lógico analítica la cual es usada en Supply Chain. Se realizó una revisión de la literatura sobre las aplicaciones de dinámica de sistemas (SD) en el área de Supply Chain, sus puntos en común y se documentaron importantes empleos de esta metodología que se han hecho en la gestión de la cadena de suministros.

A real-time thermal field theoretical analysis of Kubo-type shear viscosity: Numerical understanding with simple examples

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exploring a model of skillful engagement in nursing practice

Prominent challenges facing nurse leaders are the growing shortage of nurses and the increasingly complex care required by acutely ill patients. In organizations that shortage is exacerbated by turnover and intent to leave. Unsatisfactory working conditions are cited by nurses when they leave their current jobs. Disengagement from the job leads to plateaued performance, decreased organizational commitment, and increased turnover. Solutions to these challenges include methods both to retain and to increase the effectiveness of each nurse. ^ The specific aim of this study was to examine the relationships among organizational structures thought to foster the clinical development of the nurse, with indicators of the development of clinical expertise, resulting in outcomes of positive job attitudes and effectiveness. Causal loop modeling is incorporated as a systems tool to examine developmental cycles both for an organization and for an individual nurse to look beyond singular events and investigate deeper patterns that emerge over time. ^ The setting is an academic specialty-care institution, and the sample in this cross-sectional study consists of paired data from 225 RNs and their nurse managers. Two panels of survey instruments were created based on the model's theoretical variables, one completed by RNs and the other by their Nurse Managers. The RN survey panel examined the variables of structural empowerment, magnet essentials, knowledge as identified by the Benner developmental stage, psychological empowerment, job stage, engagement, intent to leave, job satisfaction and the early recognition of patient complications. The nurse manager survey panel examined the Benner developmental stage, job stage, and overall level of nursing performance. ^ Four regression models were created based on the outcome variables. Each model identified significant organizational and individual characteristics that predicted higher job satisfaction, decreased intent to leave, more effectiveness as measured by early recognition and acting upon subtle patient complications, and better job performance. ^ Implications for improving job attitudes and effectiveness focus on ways that nursing leaders can foster a more empowering and healthy work environment. ^

Advanced Business Simulations-Incorporating business and process execution data

Key Performance Indicators (KPIs) and their predictions are widely used by the enterprises for informed decision making. Nevertheless , a very important factor, which is generally overlooked, is that the top level strategic KPIs are actually driven by the operational level business processes. These two domains are, however, mostly segregated and analysed in silos with different Business Intelligence solutions. In this paper, we are proposing an approach for advanced Business Simulations, which converges the two domains by utilising process execution & business data, and concepts from Business Dynamics (BD) and Business Ontologies, to promote better system understanding and detailed KPI predictions. Our approach incorporates the automated creation of Causal Loop Diagrams, thus empowering the analyst to critically examine the complex dependencies hidden in the massive amounts of available enterprise data. We have further evaluated our proposed approach in the context of a retail use-case that involved verification of the automatically generated causal models by a domain expert.

A Data Driven Tool supported CLD Creation Approach

The creation of Causal Loop Diagrams (CLDs) is a major phase in the System Dynamics (SD) life-cycle, since the created CLDs express dependencies and feedback in the system under study, as well as, guide modellers in building meaningful simulation models. The cre-ation of CLDs is still subject to the modeller's domain expertise (mental model) and her ability to abstract the system, because of the strong de-pendency on semantic knowledge. Since the beginning of SD, available system data sources (written and numerical models) have always been sparsely available, very limited and imperfect and thus of little benefit to the whole modelling process. However, in recent years, we have seen an explosion in generated data, especially in all business related domains that are analysed via Business Dynamics (BD). In this paper, we intro-duce a systematic tool supported CLD creation approach, which analyses and utilises available disparate data sources within the business domain. We demonstrate the application of our methodology on a given business use-case and evaluate the resulting CLD. Finally, we propose directions for future research to further push the automation in the CLD creation and increase confidence in the generated CLDs.

SYSTEM DYNAMICS MODELING AS A QUANTITATIVE-QUALITATIVE FRAMEWORK FOR SUSTAINABLE WATER RESOURCES MANAGEMENT: INSIGHTS FOR WATER QUALITY POLICY IN THE GREAT LAKES REGION

Early water resources modeling efforts were aimed mostly at representing hydrologic processes, but the need for interdisciplinary studies has led to increasing complexity and integration of environmental, social, and economic functions. The gradual shift from merely employing engineering-based simulation models to applying more holistic frameworks is an indicator of promising changes in the traditional paradigm for the application of water resources models, supporting more sustainable management decisions. This dissertation contributes to application of a quantitative-qualitative framework for sustainable water resources management using system dynamics simulation, as well as environmental systems analysis techniques to provide insights for water quality management in the Great Lakes basin. The traditional linear thinking paradigm lacks the mental and organizational framework for sustainable development trajectories, and may lead to quick-fix solutions that fail to address key drivers of water resources problems. To facilitate holistic analysis of water resources systems, systems thinking seeks to understand interactions among the subsystems. System dynamics provides a suitable framework for operationalizing systems thinking and its application to water resources problems by offering useful qualitative tools such as causal loop diagrams (CLD), stock-and-flow diagrams (SFD), and system archetypes. The approach provides a high-level quantitative-qualitative modeling framework for "big-picture" understanding of water resources systems, stakeholder participation, policy analysis, and strategic decision making. While quantitative modeling using extensive computer simulations and optimization is still very important and needed for policy screening, qualitative system dynamics models can improve understanding of general trends and the root causes of problems, and thus promote sustainable water resources decision making. Within the system dynamics framework, a growth and underinvestment (G&U) system archetype governing Lake Allegan's eutrophication problem was hypothesized to explain the system's problematic behavior and identify policy leverage points for mitigation. A system dynamics simulation model was developed to characterize the lake's recovery from its hypereutrophic state and assess a number of proposed total maximum daily load (TMDL) reduction policies, including phosphorus load reductions from point sources (PS) and non-point sources (NPS). It was shown that, for a TMDL plan to be effective, it should be considered a component of a continuous sustainability process, which considers the functionality of dynamic feedback relationships between socio-economic growth, land use change, and environmental conditions. Furthermore, a high-level simulation-optimization framework was developed to guide watershed scale BMP implementation in the Kalamazoo watershed. Agricultural BMPs should be given priority in the watershed in order to facilitate cost-efficient attainment of the Lake Allegan's TP concentration target. However, without adequate support policies, agricultural BMP implementation may adversely affect the agricultural producers. Results from a case study of the Maumee River basin show that coordinated BMP implementation across upstream and downstream watersheds can significantly improve cost efficiency of TP load abatement.

Optimización del proceso de empaque de BANAFRUTS S.A.S. desde el punto de vista de la Teoría de Restricciones

Como resultado de la Misión Empresarial Caribe realizada por la Escuela de Administración de la Universidad del Rosario en abril de 2016, se realizó el presente documento donde se plantea una propuesta de mejora para el proceso de empaque de BanaFruts S.A.S. mediante el uso de teorías administrativas enfocadas a la gestión de calidad del producto como: Teoría de Restricciones, Kaizen y Cero defectos. La propuesta consiste en tener un proceso de control de calidad mucho menos repetitivo y más eficiente a lo largo del empaque del producto, donde solo los operarios de desmane se deberán encargar de definir cuáles bananos cumplen o no con las especificaciones de DOLE en esa etapa y además se aseguren de cumplir con nuevos límites de saturación de los frutos en las piscinas. Éstos se encontrarán en donde se alcanza el 90% de la capacidad de cada tanque. Para el de desmane estará a una altura de 0.54m; y para el de saneo estará a una altura de 0.49m. Así se actuará der manera preventiva y no reactiva como sucede actualmente, garantizando que los bananos no se lastimen y se reduzca el exceso de revisión a lo largo del proceso. Este cambio de gestión de calidad permitirá en primera instancia que los trabajadores en etapas diferentes a las de desmane se enfoquen en una sola tarea y no tengan que volver a verificar los aspectos de calidad del producto, seguido de un aumento de productividad en el procesamiento de los bananos por parte de éstos. Adicionalmente, se hace énfasis en la importancia de la mejora continua del proceso en general para asegurar un incremento gradual en la productividad. Para esto se propone un nuevo modelo de gestión de los recursos humanos donde los operarios serán más proactivos, tendrán una mayor participación en la identificación y solución de problemas y se encargarán de llevar a cabo sus labores de manera más eficiente. En este sentido, las acciones a tomar serán: seleccionar, organizar, limpiar y estandarizar. Finalmente, hay que estandarizar el proceso, es decir que debe existir una revisión continua para no permitir que los errores se repitan. Todas estas acciones estarán a cargo de un equipo líder llamado “Equipo BanaFruts”. Éste tendrá la responsabilidad de acompañar a los trabajadores en la realización de las actividades mencionadas y medir sus resultados.

The metaphysics of quantum gravity : a causal approach

The dissertation investigates some relevant metaphysical issues arising in the context of spacetime theories. In particular, the inquiry focuses on general relativity and canonical quantum gravity. A formal definition of spacetime theory is proposed and, against this framework, an analysis of the notions of general covariance, symmetry and background independence is performed. It is argued that many conceptual issues in general relativity and canonical quantum gravity derive from putting excessive emphasis on general covariance as an ontological prin-ciple. An original metaphysical position grounded in scientific essential- ism and causal realism (weak essentialism) is developed and defended. It is argued that, in the context of general relativity, weak essentialism supports spacetime substantivalism. It is also shown that weak essentialism escapes arguments from metaphysical underdetermination by positing a particular kind of causation, dubbed geometric. The proposed interpretive framework is then applied to Bohmian mechanics, pointing out that weak essentialism nicely fits into this theory. In the end, a possible Bohmian implementation of loop quantum gravity is considered, and such a Bohmian approach is interpreted in a geometric causal fashion. Under this interpretation, Bohmian loop quantum gravity straightforwardly commits us to an ontology of elementary extensions of space whose evolution is described by a non-local law. The causal mechanism underlying this evolution clarifies many conceptual issues related to the emergence of classical spacetime from the quantum regime. Although there is as yet no fully worked out physical theory of quantum gravity, it is argued that the proposed approach sets up a standard that proposals for a serious ontology in this field should meet.

Causal assessment in finite extensive-form games

Two finite extensive-form games are empirically equivalent when theempirical distribution on action profiles generated by every behaviorstrategy in one can also be generated by an appropriately chosen behaviorstrategy in the other. This paper provides a characterization ofempirical equivalence. The central idea is to relate a game's informationstructure to the conditional independencies in the empirical distributionsit generates. We present a new analytical device, the influence opportunitydiagram of a game, describe how such a diagram is constructed for a givenextensive-form game, and demonstrate that it provides a complete summaryof the information needed to test empirical equivalence between two games.