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En Colombia, la papa es un producto básico cuyo precio depende principalmente de la oferta y la demanda locales. El sector papicultor colombiano presenta grandes incertidumbres sobre los beneficios netos que se pueden generar en el corto, mediano y largo plazo, debido a la alta volatilidad de los precios del tubérculo. Este trabajo presenta un modelo de simulación de estrategias de inversión para papicultores colombianos desarrollado en la plataforma de simulación Vensim. El modelo consideró diferentes variables, entre las que se destacan el precio, el costo de la mano de obra, inversiones en nuevas tecnologías, entre otras. Con el desarrollo de este trabajo, se concluye que las utilidades de los productores son altamente sensibles a tres factores: precio, costos de producción e inflación.

Estudios previos sobre la experiencia de espera de los clients suelen centrarse sobre todo en dos áreas: la gestión de la espera y la gestión de la experiencia de espera. Existen muy pocos estudios que hayan realizado análisis y discusiones en profundidad sobre cómo los factores ambientales externos afectan a la experiencia de espera de los clientes, que se ha considerado siempre como un factor negativo que reduce la satisfacción del cliente hacia el servicio. Sin embargo, la experiencia de espera puede incrementar en reali¬dad la satisfacción del cliente hacia el servicio. Este estudio pretende profundizar en la influencia potencial de los factores que surgen del “servicescape” durante el proceso de espera del cliente, así como la interacción entre el “servicescape” y los clientes durante el tiempo de espera. Ese artículo se basa en el bucle de retroa¬limentación causal. Desde la perspectiva de la dinámica de sistemas se construye un modelo de sistemas conceptuales que muestra la interacción entre el “servicescape” y el cliente en la experiencia de espera.

El propósito del artículo de investigación es exponer el análisis prospectivo de la cadena productiva de mango en la Provincia del Tequendama - Cundinamarca por medio de la metodología de dinámica de sistemas, analizando los antecedentes, el presente y un futuro probable de esta cadena, con el fin de dar a conocer los resultados de la investigación “Mercado Prospectivo del Mango: Comparativo entre el mercado interno y el mercado externo para la Provincia del Tequendama - Cundinamarca”. Las experiencias adquiridas por medio de las visitas de campo, información primaria y secundaria, así como el proceso de modelación y simulación mediante la técnica dinámica de sistemas, permitió desarrollar el escenario prospectivo con mayor potencial para los productores de la Provincia y en consecuencia exponer las opiniones del autor con respecto a lo que deben hacer los participantes para mejorar sus condiciones de ingreso.

Este artículo propone estrategias y políticas de investigación basadas en la capacidad de apren-dizaje de las universidades (Know Why). Con la presente propuesta se busca fomentar la interacción entre los contextos empresariales, investigativo y académico. Por tanto el artículo se enfoca en la investigación como un proceso de creación e innovación basada en experiencias anteriores y en generación de conocimiento, las cuales son parte crucial de la estrategia que se propone. El diseño de políticas y estrategias de investigación tiene inmersas unas cualidades sistémicas que lo caracterizan, es por ello que a través de la metodología propuesta desde la dinámica de sistemas, se analiza el comportamiento de la investigación de una universidad y se mide la estrategia de consolidación y aprovechamiento de las capacidades internas (Know How) y capacidades de aprendizaje (Know Why).

Es complejo para gestores y administradores conocer las implicaciones que la adopción de modelos de desarrollo de software tendría para una región. Este artículo ofrece una evaluación de las implicaciones dinámicas que para el desarrollo de software de una región tendría el apostar de forma excluyente al software libre, al software de fuente abierta y al software propietario. Se desarrolló un modelo de simulación en Vensim de la dinámica de sistemas en donde se evaluaron 3 escenarios: uno en donde se adopta de forma excluyente el software libre, uno en donde se adopta el software propietario y uno en donde se adopta el software de fuente abierta. Se ofrecen descripciones y explicaciones de los resultados que sugieren las potencialidades de cada uno de los modelos de desarrollo evaluados.

El oasis de Comondú es un agroecosistema de gran riqueza ecológica y cultural estrechamente ligado a la presencia de agua en un entorno árido. La subsistencia de sus poblaciones desde antes de la época misional hasta nuestros tiempos es una muestra explícita de sustentabilidad. Sin embargo, condiciones socioeconómicas y ambientales externas han desequilibrado este sistema socioambiental, que se dirige a su declive y desaparición. Nuestro objetivo general es evaluar la sustentabilidad de este sistema socioambiental mediante el enfoque de indicadores integrados en modelos dinámicos. El objetivo de este artículo es presentar este emergente enfoque y mostrar los primeros pasos de esta investigación: la construcción participativa de un modelo conceptual de nuestro sistema de estudio. Hemos identificado las principales variables e interrelaciones, y los procesos históricos que han influido en su dinámica. El modelo conceptual resultante incluye los subsistemas social y económico-productivo. La dinámica general del sistema de Comondú se encuentra en gran medida bajo el control de variables externas, climáticas como huracanes y precipitaciones, y de carácter socioeconómico, como la deslocalización sociopolítica, las ayudas gubernamentales y la intensificación agrícola exterior.

Introduction: Fast population growth has generated an increase in the consumption and therefore it has influenced the rise of the solid waste generation, which causes adverse effects on the environment if treated inadequated. Polyethylene terephthalate (PET) is a kind of solid waste generated that is 100% recyclable, however it is ending in landfills reducing the lifespan of them and consuming resources like petroleum in order to generate new products. Objective: Evaluating the effect on the environment of PET recycling by means of a system dinamics model. Material and method: The variables considered were water and energy consumption, CO2 emissions and landfill lifespan varying the PET recycling rate. RESULTS: the increase of the recycling rate cause a decrease in water and energy consumption as well as de CO2 emissions and produce a rise in the landfill lifespan. Conclusions: It is still important to follow the acomplishment of the solid waste management policies so as to enhace the decision making process related to generate a positive impact on the environment. [ABSTRACT FROM AUTHOR]

Introduction: The pigeons (Columba livia) are a cultural part of the historical centers of the great cities of the world; however, they are an invasive species that can become a threat to the public health of visitors to the Plaza de Bolívar in Bogotá, which is why it is necessary to control the net increase of these birds, without seeking extinction. Objective: In this work a mathematical model of the population growth of pigeons was constructed, under a series of control pulses through time, to observe the behavior of controlled development of these birds. Materials and Methods: As a main tool we used the modeling methodology known as System Dynamics, which allows us to obtain a system of differential equations from a systemic representation of a problem. Results: The results indicate that the simulation of this type of control allows the population of pigeons to remain within an acceptable range for space. Conclusions: This work is considered a great contribution in the simulation and evaluation of scenarios for the population control of pigeons, through the evaluation with Systems Dynamics and can be reproduced for other problem species. [ABSTRACT FROM AUTHOR]

The objective of this work is to analyze the energy consumption of a system of public passenger electric traction from a systemic perspective, based on the simulation with Dynamics of Systems. As a case study, the Mass Transit Company of the Valley of Aburrá is analyzed. The analysis considers a key archetype for the approach of the dynamic hypothesis: the limits of growth. The results obtained in the simulations showed how the use of the capacity of the electrical infrastructure, with the incorporation of new expansion projects, could limit its capacity to operate in the face of contingencies. It is concluded that the planning must take into account that the efforts done to expand the system are successful in the initial stages, but when they reach the limits of growth and begin to lose effectiveness. Therefore, the performance starts to decrease, affecting the supply capacity of the transport service. [ABSTRACT FROM AUTHOR]

This article presents the systemic analysis of the components of security with the use of the languages of systems dynamics such as the prose, influence diagram, flow-level, equations and behaviors. Systems dynamics allows the analysis of the complexity of security's elements through the characterization of the existing feedback cycles, for the perception, explanation and prediction of security. The usefulness of the proposed model is shown through the simulation of hypothetical scenarios, allowing in this way measuring information security. [ABSTRACT FROM AUTHOR]

La cadena de suministro del sector lácteo está conformada por cuatro eslabones: el primario o ganadero, el industrial o de transformación, el comercializador y el de consumo. El primero, es el que ofrece mayor oportunidad para incrementar la productividad y así lograr mayor competitividad. En este sentido, se busca avanzar de 4,5 litros/día/vaca a 15,2 litros/día/vaca, valor que se registra en países como Nueva Zelanda. Dado que el costo del ordeño manual representa un 43% del costo de mano de obra y éste representa el 66% del total de los costos de producción por litro de leche, la automatización del ordeño ofrece una reducción en estos e incremento en la productividad, sin embargo, produce un aumento en el costo de maquinaria. Al compararlos con el precio de venta se obtienen beneficios que recibe el ganadero. Estos beneficios se reinvierten en equipos de automatización permitiendo el incremento en la productividad y competitividad del eslabón primario. Para tal efecto, se realiza un modelamiento, a través de dinámica de sistemas ajustado a los parámetros de producción, población y cabezas de ganado productivas. Se evalúan escenarios, en donde se evidencia la mejora en la productividad del ganado, los hatos y la demanda de productos lácteos, dando como resultado que las buenas prácticas de manufactura impactan las inversiones intensivas en tecnificación de los hatos. [ABSTRACT FROM AUTHOR]

Introduction: The supply chain is an underestimated issue in small and medium enterprises; it is assumed that its only purpose is to save on operating costs and this is not necessarily the case. It is imperative to recognize that not all customers are equal, as each has different requirements for their products and delivery of same to their final customers, and it is therefore important to consider all the factors that influence that outcome. The case study was developed in a company producing plastic containers in Cd. Obregon, Sonora. The study has selected the manufacture of the 737 gr salt container from resin, as this is a product demanded by one of its three main customers. The problem in the plant was the number of salt containers to be produced with different production policies, generating three scenarios. Method: To respond to the problem, a study of the entire production process associated with the links in the supply and distribution was conducted based on the methodology of system dynamics to evaluate each of the variables and parameters included in the links in the supply chain via a simulation. Results: The results show three different scenarios that are executed through an interface with the user, allowing to observe the behavior of the profits, the sales of finished product and the use of the resin in the manufacture of bottles of 737 gr for a company that manufactures and distributes salt proposals were validated by drawing upon the judgment of experts on the subject and the experience of employees, as well as the actual data of the Company Discussion or Conclusion: The findings reveal different modes of behavior of four critical variables in the process: profits, sales, the finished products warehouse, and resin use. The simulation was performed with the use of Stella ® 10.1.2 software, trying different policies and considering delay and initial inventory theories in processes and final products for the three different proposed scenarios derived from this study to interested parties (employers and customers); the case study was developed within the context of the National Center for Innovation in Intermodal Transportation and Logistics of Mexico. [ABSTRACT FROM AUTHOR]

Medical emergency services can be overcrowded due to both external and internal service factors. This is evinced in the congestion, longer waits, and dissatisfaction by the users. To identify and simulate strategies for processing medical emergency requests in order to mitigate the overcrowding. An exploratory and analytical research was conducted based on the field work at four emergency rooms in hospitals of Medellín; simulation strategies were then proposed against the overcrowded service with system dynamics. The strategies included: to reorganize the sign-in, refer to other places those patient not requiring emergency services, implement fast-track services, and increase the inpatient capacity. The last one becomes the most effective strategy in the simulation. While the flow strategies can help to solve the service overcrowding due to internal causes as suggested in the literature, these strategies are limited in their scope. The required patient sign-in strategies as well as the patient discharge strategies are not easy-to-do in these emergency rooms. Overcrowding can be reduced by thinking of the hospital and the emergency room as two elements in a single system, so that the patient flow can be speeded up; the bed number for inpatients must be improved without overflowing the hospital capacity. [ABSTRACT FROM AUTHOR]

Thermal environment is recognized to be one the most important ecological factor to determine domestic animal growth, development and productivity for direct and indirect effects on its physiology and behavior. Despite having specific and individual adaptation, is very common, within seasonal or diurnal temperature variations, animals deal with situations outside their thermal comfort zone. Due to heat stress, dairy cows reduce milk production and fertility, and therefore, had achieved an increasing in metabolic disorders incidence, causing low revenues to farm in short and medium periods. Due to world climate change more impact of the meteorological variables on animal responses is expected for the future. This study aimed to describe and understand the interactions of variables associated with heat stress in dairy cattle. System thinking approach to this specific physiological mechanism might help to better focus managerial aspects related to grazing conditions and animal needs. A causal loop diagram annotation used to connect biological variables included in system boundaries. Causal connections were validated with literature citations on the heat stress influence. The most important feedback loops highlighted underline dominant structure and expected patterns. Four balancing loops involved in physiological mechanisms used by animals in order to reduce metabolic heat production and to regulate homeostasis of the internal temperature, were found. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Action Research is the property of Verlag Barbara Budrich GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Uno de los supuestos principales del análisis de regresión lineal es la existencia de una relación de causalidad entre las variables analizadas, sin que el análisis de regresión lo permita demostrar. Esta investigación demuestra la causalidad entre las variables analizadas a través de la construcción y análisis de la retroalimentación entre las variables en estudio, plasmada en un diagrama causal y validado a través de simulación dinámica. Una de las principales contribuciones de ésta investigación, es la propuesta de utilizar un enfoque de dinámica de sistemas, para desarrollar un método de transición de un modelo de regresión lineal múltiple predictivo a un modelo de regresión no lineal simple explicativo, que incrementa el nivel de predicción del modelo. El error cuadrático medio (ECM) es utilizado como criterio de predicción. La validación se realizó con tres modelos de regresión lineal obtenidos experimentalmente en una empresa del sector textil, mostrando una alternativa para incrementar la fiabilidad en los modelos de predicción.

El sistema minero aurífero es un sistema complejo caracterizado por las interacciones entre individuos, organizaciones y otras variables que intervienen en su comportamiento. Tal sistema está integrado por los procesos de exploración, extracción, beneficio y comercialización. En el caso colombiano, factores exógenos de tipo social, ambiental, político, económico, tecnológico y organizacional intervienen en el desarrollo y la productividad de dichos procesos, agregándole una mayor complejidad al sistema. Para analizar tal complejidad, se desarrolla un modelo de dinámica de sistemas (DS) que permite la caracterización del sistema y la evaluación de políticas para el mejoramiento de la productividad de un proceso minero aurífero en Colombia. Se presentan simulaciones de diferentes escenarios, donde se observa que políticas de inversión sostenibles incrementan la productividad de dicho proceso. Finalmente, cambios positivos en las actividades generadoras de capital social y la infraestructura física de la región de influencia tienen un impacto positivo sobre la productividad multifactorial del proceso minero aurífero colombiano.

Political transitions often trigger substantial environmental changes. In particular, deforestation can result from the complex interplay among the components of a system-actors, institutions, and existing policies-adapting to new opportunities. A dynamic conceptual map of system components is particularly useful for systems in which multiple actors, each with different worldviews and motivations, may be simultaneously trying to alter different facets of the system, unaware of the impacts on other components. In Myanmar, a global biodiversity hotspot with the largest forest area in mainland Southeast Asia, ongoing political and economic reforms are likely to change the dynamics of deforestation drivers. A fundamental conceptual map of these dynamics is therefore a prerequisite for interventions to reduce deforestation. We used a system-dynamics approach and causal-network analysis to determine the proximate causes and underlying drivers of forest loss and degradation in Myanmar from 1995 to 2016 and to articulate the linkages among them. Proximate causes included infrastructure development, timber extraction, and agricultural expansion. These were stimulated primarily by formal agricultural, logging, mining, and hydropower concessions and economic investment and social issues relating to civil war and land tenure. Reform of land laws, the link between natural resource extraction and civil war, and the allocation of agricultural concessions will influence the extent of future forest loss and degradation in Myanmar. The causal-network analysis identified priority areas for policy interventions, for example, creating a public registry of land-concession holders to deter corruption in concession allocation. We recommend application of this analytical approach to other countries, particularly those undergoing political transition, to inform policy interventions to reduce forest loss and degradation. [ABSTRACT FROM AUTHOR]

The purpose of this study is to analyze the cotton agro-chain in Colombia using systems dynamics to identify potential logistic and decision-making improvements, taking into account the growth and variables as a harvested area and production of the cotton sector in Colombia. The results will show a current own analysis of the sector and its scenarios based on variables such as price, supply, production capacities, among others. These results will provide a clear diagnosis of the current sector in terms of annual production and production times in order to create a model that generates improvements in the variables and the inclusion of policies and practices that drive the cotton chain in logistic and economic terms. The scenarios proposed in the study show a high correlation for the data provided by the entities interested in this sector, indicating that the system dynamics model turns out to be an ideal tool, in the creation of scenarios mainly to the ease of interaction and interpretation of the results. [ABSTRACT FROM AUTHOR]

We introduce a simplified ecohydrological model to quantitatively assess the resiliency and stability of ecosystems over long periods. The model couples a hydrological soil moisture balance with a set of spatiotemporal systems dynamics and agent-based algorithms to represent the interactions among several plant populations in a gridded area under different water, soil and temperature constraints. We characterize the plant populations by allometric rules (i.e., power laws for generational and reproductive times; linear approximations for water and temperature gains, losses and optimal values; and a set of intra and interspecific interaction rules based on high, optimal and low competition responses among the populations), that represent different plant phenotypes. We define the disturbances by a clearance of populations in an area within the model's domain and calculate the resiliency and stability with simple indices to determine the ability of the ecosystem to recover from a disturbance. The indices evaluated on each population and over the structure of the entire ecosystem show how the populations respond differently to disturbances, following patterns similar to those expected in nature. The model can represent the spatial and temporal succession of the ecosystem after being disturbed, suggesting how the differences in the phenotypical characteristics of plant populations can be advantageous or disadvantageous for the ecosystem recovery. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Policy & Complex Systems is the property of Policy Studies Organization and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Policy & Complex Systems is the property of Policy Studies Organization and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Future Studies Research Journal: Trends & Strategies is the property of Future Studies Research Journal: Trends & Strategies and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents a system dynamics model which evaluates the environmental impact caused by the reverse logistics of car tires. System dynamics is used to explain the behavior of the emissions generated by four processes, the production of new tires, retreading, mechanical crushing and co-processing, the last three refer to processes where you can use the tires once these become waste. The environmental impact of reverse logistics network allows the analysis of different environmental variables that characterize the system, among which are the carbon dioxide emissions, oil consumption and water consumption. Different scenarios are also analyzed to evaluate the sensitivity of the proposed model and identify the disposal that generate more and less contamination, as well as to recognize the production process that reduces emissions. [ABSTRACT FROM AUTHOR]

Among the preparation measures that enable the population to respond quickly and effectively to disasters, is the implementation of early warning systems. So, this paper aims to represent the complexity of the process of issuance of natural disasters early warnings and to check on if and how behavioral and underlying factors to decision making can impact the effectiveness of the alert. In order to support this study, a System Dynamics model for an early warning system will be developed, based on a case study applied to the National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN). As a result, it is hoped to demonstrate to decision-makers and managers, through a systemic view of the process, like cause and effect relationships between important elements of decision making can affect the performance of the early warnings over time, as well as subsidize the adoption of strategic actions to correct eventual system failures, thus reducing the occurrence of false alerts, lost events and early warnings issued with delays. In addition, the developed model may result in an organizational learning and testing mechanism for strategic planning. [ABSTRACT FROM AUTHOR]

The contribution of Colombia to global emissions of greenhouse gases (GHGs) is low (0.37%); from this percentage, 38% is attributed to agriculture. There are few studies on GHGs emissions at the regional level for agriculture. Therefore, the aim of this research is to estimate dynamically GHG and carbon footprint produced by cattle in the department of Valle del Cauca, Colombia. GHG estimates were established as follows: Tier II of IPCC methodology (2006), and population trends, which were simulated using dynamic system. According to the departmental livestock inventory in recent years (2009-2015), average emissions were 673 million of 2eq. year2, with emissions intensity (EI) of 5.58 kg2eq.kg.milk2 and 3.54 kg2eq.kgmeat2. Simulating the behavior of the bovine population (2016-2035), based on historical trends, the number of animals and emissions tended to reduce. The simulated EI was in 4.1 - 4.2 kg2eq.kg.milk2 and 3.7 - 3.9 kg2eq.kg.meat2. Increasing birth rates (83 to 90%), lower age at first birth (34 to 30 months), increased milk production per cow per day (5.33 to 10 kg), increased production of milk and meat in 100 and 4 million kg per year, respectively; with decrease in EI of 1.4 for milk and 2 units for meat. This study showed selecting efficient animals (productively and reproductively), can produce more animal protein with less carbon footprint. [ABSTRACT FROM AUTHOR]

Research capacities are developed scientific skills that enable universities to accomplish the dissemination of high-quality scientific knowledge. Nowadays, the modeling of their dynamics is one of the most important concerns for the stakeholders related to the scientific activity, including university managers, private sector and government. In this context, the present article aims to approach the issue of modeling the capacities of the Universities' research systems, presenting Systems Dynamics as an effective methodological tool for the treatment of data contained in intellectual capital indicators, allowing to estimate parameters, conditions and scenarios. The main contribution lays on the modeling and simulations accomplished for several scenarios, which display the critical variables and the more sensitive ones when building or strengthening research capacities. The establishment of parameters through regression techniques allowed to more accurately model the dynamics of the variables. This is an interesting contribution in terms of the accuracy of the simulations that later might be used to propose and carry out changes related to the management of the universities research. Future research with alternative modeling for social systems will allow to broaden the scope of the study. [ABSTRACT FROM AUTHOR]

Copyright of Ambiente y Desarrollo is the property of Pontificia Universidad Javeriana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Investigación e Innovación en Ingenierías is the property of Universidad Simon Bolivar and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Dimensión Empresarial is the property of Universidad Autonoma del Caribe, Departamento del Atlantico and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The computer security enables organizations to protect their financial resources, information systems, reputation, legal situation, and other tangible and intangible properties. The main objective of this paper is to develop a simulation model to evaluate the optimal level of security that must have the organizations, considering aspects related to the reduction of the risk and the acquisition of business benefits. The technique used for the construction of the model was dynamic systems, which allows analyze the behavior of complex systems in the short, medium and long term. The model was built with the software "POWERSIM", which is an integrated environment for the construction and use of simulation models of business. With the development of the model it concludes that if the organizations do not have a master plan to guide efforts to protect the assets, by a lot of money to invest in security never reach satisfactory levels of safety. [ABSTRACT FROM AUTHOR]