System Dynamics Modeling

University management implies a great variety of decisions that need to be made in order to maintain financially affordable programs that successfully meet the educational demand and thus achieving a generally understood goal which is that the University works as a self-sustainable system. The Systems Thinking research group (GPS) has developed a variety of projects which main purpose was to use System Dynamics modeling to support University management at Universidad Autónoma de Bucaramanga. A detailed revision of these projects is presented to distinguish common objectives, methods and strategies, organizational learning experiences and along with them, a variety of uses of System dynamics tools that are to be discussed leading towards an extensive reflection about organizational complexities beyond management strategies.

Das Workgroup Computing Competence Center Paderborn befaßt sich mit Forschung, Prototyping, Produktentwicklung, Systemeinführung, Projektabwicklung, Technologietransfer, Consulting und Schulung bei Groupware-basierten Anwendungen für betriebliches Informationsmanagement. Gegenstand sind insbesondere Businessund Technologie-Frameworks für Office Systeme, Workgroup Computing, Workflow Management, Projekt Management und Connectivity-Systeme in Client-Server Architekturen. Das Workgroup Computing Competence Center Paderborn besteht aus gemeinsamen Arbeitsteams an der Universität Paderborn und der PAVONE Informationssysteme GmbH Paderborn.

In this paper, we propose a controller for multicontact legged robots that takes into account the contact compliance. This controller is able to achieve both balance stabilization and force control in the same loop in task space thanks to the use of an explicit contact flexibility model and simplified centroidal dynamics that allow exploiting the redundancy of the kinematic and force feedback. The control problem is formulated as an LQR based on a linearized model of the reduced non-linear model. The performance of the controller with regard to robustness to modeling error and external perturbations has been tested in simulation, and compared to a stabilizer based on the zero-moment-point feedback within a control that generates the desired contact forces with the environment.

In this paper, we attempt to invent a new way to understand risk, measure it, and weigh its consequences. We attempt to design a rational process for risk-taking; a process that gives the system dynamicist the ability to define what may happen in the future and then to choose among alternatives.

The purpose of the System Dynamics method is to study the relationship between structure and behavior in non-linear, dynamic systems. In such systems, the significance of various structural components to the behavior pattern exhibited, changes as the behavior unfolds. Changes in structural significance, in turn modifies that behavior pattern, which, in turn, feeds back to change the relative significance of structural components. We develop a mathematical framework within which we can study the characteristics of this feedback ...

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No one can predict the future of a country in turmoil. However, we have faced times of turbulence before, and despite these, our overall population and economy have maintained momentum throughout the 80-year post-war period. This period has also seen steady declines in fertility rate, mortality rates (from infants through the elderly), and the carbon intensity of GDP. Although there is no guarantee that these past trends will continue, we can use them as a starting point for informed modeling and policy conversation. Agencies such as the Census, the World Bank, and the Energy Information Administration have recorded these trends and made projections based on highly detailed algebraic models with modifiable future assumptions. But these models are unavailable to the general public and sit unconnected to each other. Here I present a “do-it-yourself” simulator of the US that fits official data from 1950 onward, is conceptually straightforward, projects to 2100, and allows experimentation with six key future assumptions.

The article presents the fifty-year history of Lubelski Węgiel "Bogdanka" S.A. – from the initial concepts of developing the Lublin Coal Basin in the 1970s, through the construction of a pilot-mining colliery, to its current status as one of the most modern and efficient coal mines in Poland. It discusses pioneering works related to shaft sinking by ground-freezing in complex hydrogeological conditions, as well as technical and organizational challenges of the 1975–1985 period and the operational experience of the first years. The 1990s are described as a time of transformation into an independent marketoriented enterprise, able to achieve positive financial results and maintain high productivity. The early 21st century marked the expansion of the Stefanów field and dynamic growth of production, while today the mine is characterized by automation, advanced monitoring systems and innovative technologies ensuring efficiency and occupational safety. The article also emphasizes Bogdanka’s social role, its contribution to the development of Łęczna and the Lublin region, and its importance for Poland’s energy security and economic transition.

Do scharakteryzowania właściwości fizykochemicznych pirytu mineralnego i węglowego po aktywacji mechanicznej wykorzystano wyniki analizy chemicznej, rentgenograficznej, skaningowej analizy mikroskopowej, mikroanalizy rentgenowskiej, spektroskopii w podczerwieni oraz pomiarów powierzchni właściwej metodą BET. Stwierdzono, że aktywacja mechaniczna powoduje zmianę wielkości powierzchni właściwej oraz dystorsję sieci krystalicznej pirytu węglowego i mineralnego w różnym stopniu. Po 5 min. aktywacji powierzchnia właściwa pirytu węglowego wzrasta dziesięciokrotnie natomiast mineralnego tylko pięciokrotnie. Próby testujące ługowania żelaza z obu pirytów w 2M roztworze kwasu solnego wykazały większą reaktywność pirytu węglowego niż mineralnego. Słowa kluczowe-hydrometalurgia, aktywacja mechaniczna, piryt, ługowanie WPROWADZENIE Aktywacja mechaniczna polega na intensywnym mieleniu ziaren minerału do wymiarów kilku µm. W ostatniej dekadzie obserwuje się intensywny rozwój badań nad wpływem aktywacji mechanicznej na wydajność ługowania

The Collaborative Networks (CN) discipline has been largely studied in last decades, addressing different problems and proposing solutions for the robust establishment of collaborative processes, within the enterprises willing to collaborate. The main aim of CN research is, therefore, to generate approaches that enable creating effective relationships in the long term, to achieve stable and agile alliances. The concept of alignment among the CN partners has been considered since the beginning of CN research. Nevertheless, novel perspectives of study in CN, such as the consideration of collaborative emotional states, within the CN, have been introduced in recent years. This paper connects the research area of strategies alignment and the CN emotion models. Accordingly, a modelling framework to assess strategies alignment considering the emotional environment within the CN is proposed. The modelling framework allows representing how the enterprises emotions affect in the selection and alignment of formulated enterprises' strategies.

This concluding chapter synthesizes the empirical findings from the Probrands Zimbabwe case study, drawing meaningful conclusions about supply chain management practices and their impact on operational efficiency within the challenging Zimbabwean manufacturing context. The investigation examined how supply chain management practices influence operational efficiency, specifically focusing on order fulfillment rates as the primary performance metric. Each objective revealed distinct patterns of strength and weakness within Probrands' supply chain operations, providing rich insights into the complex interplay between various SCM components. This chapter progresses through a systematic summary of major findings aligned with each research objective, followed by evidence-based conclusions that address the research questions comprehensively. Subsequently, practical recommendations tailored to Probrands' specific operational context are presented, drawing from established supply chain best practices while considering local constraints. Finally, the chapter identifies promising avenues for future research that could extend understanding of supply chain dynamics in emerging economies.

Streszczenie. W pracy dokonano przeglądu termodynamicznych metod określania równowagi układów chemicznych, które, zastosowane w kodach termochemicznych, pozwalają wyznaczyć parametry przemian przebiegających w materiałach wysokoenergetycznych. Pokazano powiązania różnych metod z potencjałem chemicznym reagujących składników i omówiono sposoby wyznaczania równowagi dla reaktywnych, idealnych układów substancji chemicznych.

Health planners in the Division of Diabetes Translation and others from the National Center for Chronic Disease Prevention and Health Promotion of the Centers for Disease Control and Prevention used system dynamics simulation modeling to gain a better understanding of diabetes population dynamics and to explore implications for public health strategy. A model was developed to explain the growth of diabetes since 1980 and portray possible futures through 2050. The model simulations suggest characteristic dynamics of the diabetes population, including unintended increases in diabetes prevalence due to diabetes control, the inability of diabetes control efforts alone to reduce diabetes-related deaths in the long term, and significant delays between primary prevention efforts and downstream improvements in diabetes outcomes.

Navigating Health Futures in a Dynamic and Democratic World Each life is a story. Some are long, rich epics filled with happiness, health, and rewarding work, while others--far too numerous--are punctuated by excessive adversity, affliction, and loss. Often, helping to define and ameliorate those extremes is another kind of story: the rapidly evolving drama of our collective effort to establish and maintain the conditions necessary for health. In Hygeia's Constellation, the focus is on both health protection, over time and across places, as well as health equity. It is a unique inquiry into the dynamic and democratic dimensions of health in the 21st Century. Hygeia's Constellation points the way toward a promising new horizon for thinking and action at a time when health threats and the provision of healthcare are increasingly complicated, and health professionals of all types are challenged to respond. Building on past and current innovations, Bobby Milstein asks us to think differently: to consider more than one problem at a time; to see the health landscape in larger, more dynamic terms; and to question what exactly each of us can do, across our respective spheres of influence, to create the conditions for a healthier, more equitable future. Health systems in the United States and around the world are rapidly changing, and need to be guided by an orientation in which problems are confronted in a holistic manner that acknowledges both their contours and connections. The grave dangers and abundant opportunities that characterize today's health protection enterprise require a broad outlook to navigate health futures--the alternative trajectories that could unfold for the people's health over time. Hygeia's Constellation is an arresting resource that should be read by every health professional. Readers will be inspired and challenged to learn how their work, along with that of their fellow citizens, may indeed provide the leverage necessary to create a healthier, happier, and more prosperous future for all. Please join us in exploring this unique perspective and its power to transform our daily efforts to protect the public's health and achieve health equity.

In addressing management scenarios and climate changes, it is necessary to consider surface water and groundwater resources as an integrated system. In this context, the present research first simulates and evaluates surface water and groundwater simultaneously; then, it examines the possible effects of climate change on these water resources in the study area (Mahabad, Northwest of Iran). In the first stage, the WEAP-MODFLOW model was applied to a 10-year period (2006-2015) in order to take into account the interactions between surface water and groundwater and calibrate the amount of recharge and drainage from the aquifer. In the second stage, in order to study the effect of climate change on surface water and groundwater resources, we compared the micro-scale model outputs under the RCP4.5 scenario for different climate change models in the period 2021-2045. The results show that root-mean-square error (RMSE) and mean absolute error (MAE) scores are equal to 0.89 and 0.79 in unsteady conditions, respectively, which confirm the efficient performance of groundwater simulation. In addition, the results of the WEAP model based on MARE assessment criteria for calibration and validation modes are equal to 0.54 and 54.0, respectively. This finding provides evidence for the efficient performance of the simulation model. Once the interactions between groundwater and surface water were specified, the results R 2 and NS suggested that indices were equal to 0.62 and 0.59, respectively, for Mahabad hydrometric station. The efficient performance of the proposed model for runoff simulation was therefore confirmed. Owing to climate change in the study period, groundwater decreased by about 1.6-1.9 m. Moreover, the amount of runoff declined from 0.1 to 0.001 MCM/month in all months except December. Unless appropriate decisions are taken to improve groundwater and strategies are applied to reduce the effect of climate change, under the present conditions this region will suffer irreparable damages in the future.

W zakładach przeróbki węgla zmiany założeń produkcyjnych (wynikające z konieczności realizacji kontraktów handlowych) oraz różnorakie zakłócenia procesów produkcyjnych prowadzą do uzyskiwania różnych punktów pracy struktury technologicznej zakładu przeróbki węgla, będącego złożonym układem sterowania ekstremalnego . Optymalne decyzje sterujące, maksymalizujące oczekiwane efekty sterowania nadrzędnego, np. uzyskania maksymalnej wartości produkcji o zadanej jakości, można rozwiązywać z wykorzystaniem optymalizacji statycznej . Zmieniając parametry rozdziału operacji przeróbczych można sterować przebiegiem procesów przeróbki węgla. Odpowiedni dobór wartości tych parametrów pozwala na uzyskanie określonych cech produktów oraz maksymalnej wartości produkcji . W procesach flotacji rud metali dodatkowo stosuje się ponowne wzbogacanie części produktów , czyli recyrkulację produktów. Również w przypadku flotacji węgla możliwe jest uzyskanie lepszych wyników wzbogacania, poprzez zastosowanie recyrkulacji produktów . W przedstawionym referacie rozpatrzone zostały zagadnienia sterowania dotyczące fragmentu układu technologicznego, mianowicie wzbogacania węgla energetycznego w cyklonach wodnych i cyklonach cieczy ciężkiej z recyrkulacją strumieni produktu pośredniego. Wyznaczone zostały optymalne wartości gęstości rozdziału w cyklonach przy różnych założeniach produkcyjnych co do jakości koncentratu. W opracowaniu podane zostały efekty ekonomiczne, w postaci względnej wartości produkcji, uzyskiwane przy dwóch różnych sposobach recyrkulacji strumienia produktu pośredniego z cyklonów. Analizy wzbogacania w złożonym układzie technologicznym z recyrkulacją strumieni produktów podane zostały w monografii [5] i referacie .

Most analyses of the relationship between spatial clustering and the technological learning of firms have emphasised the influence of the former on the latter, and have focused on intra-cluster learning as the driver of innovative performance. This paper reverses those perspectives. It examines the influence of individual firms' absorptive capacities on both the functioning of the intra-cluster knowledge system and its interconnection with extra-cluster knowledge. It applies social network analysis to identify different cognitive roles played by cluster firms and the overall structure of the knowledge system of a wine cluster in Chile. The results show that knowledge is not diffused evenly 'in the air', but flows within a core group of firms characterised by advanced absorptive capacities. Firms' different cognitive roles include some -as in the case of technological gatekeepers -that contribute actively to the acquisition, creation and diffusion of knowledge. Others remain cognitively isolated from the cluster, though in some cases strongly linked to extra-cluster knowledge. Possible implications for policy are noted.

Eine wachsende Anzahl von Eingangsgrößen für Management-Informationssysteme (MIS) im Bauwesen wird mittlerweile automatisch und nahezu in Echtzeit erfasst. Um dieses Potenzial voll auszuschöpfen, müssen MIS die erfassten Daten in derselben Frequenz analysieren und daraus konkrete Handlungsempfehlungen ableiten. Das kontinuierliche Erfassen von Informationen ist von begrenztem Nutzen, wenn die Auswertung nur in langen Zeitintervallen erfolgt. Durch das Automatisieren von Bewertungs-und Entscheidungsprozessen können Bauprojekte effizienter gesteuert und fundiertere Entscheidungen getroffen werden. Der präsentierte Forschungsansatz kombiniert regelungstechnische Prinzipien mit der System-Dynamics-Methode. Ziel ist die Entwicklung eines MIS, welches Projektmanager bei der Beantwortung zentraler Fragen unterstützt: Welche Steuerungseingriffe sind erforderlich, mit welcher Intensität, für welche Dauer und in welcher Reihenfolge, um den aktuellen Projektstatus möglichst nah an den angestrebten Zielzustand heranzuführen? Dazu wird auf bestehende Informationsquellen zurückgegriffen, sodass keine zusätzlichen Strukturen erforderlich sind.

IranDoc was founded in September 1968 with the aim of promoting and developing information management, training for research cooperation and supporting science and technology activities in Iran. Today, it is one of the most successful research and information centers that has been able to initiate valuable policies for the development of its information materials, databases, and human resources. Also, Irandoc has been trying to launch and provide several systems based on the latest developments to provide better services. Now, with the beginning of the second half century of its activities, it is necessary to consider certain measures and activities to guide research policies by processing and creating added value out of its resources and services. For this purpose, a list of activities are suggested in this paper such as reviewing the user interface of the systems and considering the possibilities of obtaining output for research activities, removing repeated registrations and obtaining different services with one account, collecting and organizing research projects and theses of a wide range of universities under the authority of the two Iranian ministries (the Ministry of Science, Research and Technology and the Ministry of Health and Medical Education) as well as non-governmental institutions of higher education, providing scientometric services based on the data available in Irandoc systems, setting up a huge system of questionnaires and checklists, picking up sources at the end of theses and presenting them independently as well as creating a link between the sources and the text, launching a system of suggested research topics, strengthening the resources of Irandoc through public appeals, and holding the festival of "Research in Research".

En la configuracion de una teoria, el proceso de reconstruccion de un modelo matematico permite orientar las actividades experimentales y la simulacion en los sistemas en estudio. A partir de ello, es posible definir  las funciones de transferencias en tiempo continuo o discreto. En base a ello proponemos, en el estudio de sistemas oscilatorios, la implementacion de estrategias didacticas alternativas para fortalecer la  comprension del fenomeno en estudio.

Technologia podziemnego upłynniania węgla zapewnia niskie koszty wdrożenia dzięki prostemu procesowi, produkuje płynne i gazowe węglowodory w złożu, eliminując koszty wydobycia i transportu, umożliwia wykorzystanie nierentownych złóż (np. kopalnie w Bytomiu i Zabrzu lub złoża zagraniczne) oraz zmniejsza wpływ na środowisko w porównaniu z tradycyjnym wydobyciem.

As globalization reshapes our industries worldwide, supply chain management has evolved into highly interconnected ecosystems. This shift requires companies to share information across continents within seconds, helping them coordinate operations and quickly adapt to changes. Although the effects are observed on a global scale, they can be systematically examined and addressed through micro-level analysis within the supply chain analysis, which remains insufficiently explored in the existing literature. Hence, this study aims to investigate micro-level analysis, simulating how different delivery strategies can be adopted for houses, departments, and apartments within a specific region. The simulation integrates real-time distribution centers and customer locations, delivery sequence, delivery time, and actual delivery route. The MOST (Maynard Operation Sequence Technique) analysis technique and a Monte Carlo simulation analysis were employed to ensure data accuracy in the simulated scenarios. In addition, the results obtained from this analysis were mapped using GIS information in AnyLogic simulation software. This study demonstrates the importance of performing a micro-level analysis with key performance metrics, including the number of required vehicles, completed delivery, total delivery time, utilization rate, and overall profit. The result also highlights scenarios in which companies with fewer employees may struggle to meet delivery requirements, leading to employee dissatisfaction from high workloads and customer dissatisfaction due to missed deliveries.

In practice, robots operate as nonlinear systems and often encounter factors like nonlinear friction, load variations, and external disturbances during tasks. To address these challenges, a smart control approach has been developed that combines the strengths of fuzzy logic and sliding mode control (SMC) for precise robot manipulator positioning. The key benefit of SMC lies in its robustness, maintaining stability despite noise or parameter changes in the system. However, designing an SMC system often faces difficulties due to practical limitations, making deployment not always feasible in real-world applications. Additionally, a large control law amplitude can lead to chattering around the sliding surface. To overcome these issues, the study introduces a fuzzy logic-based method to adaptively estimate the control law's magnitude, guided by Lyapunov stability principles. This control scheme is tested on a four-degree-of-freedom robot manipulator, with simulation results confirming its effectiveness in MATLAB.

The purpose of this research is to analyze the effect of exports, labor, and average wages on Indonesia's Gross Domestic Product (GDP) through the creative economy sector in the period 2010 -2016, use only seven of the sixteen former creative economic sub-sectors namely animated and video films, craft, culinary, music, fashion, publishing, fine art. This study use secondary data and the analytical method use panel data regression with the best approach, Random Effect Model. The results of the study show that simultaneously the variables of exports, labor, and average wages have a significant and positive influence on the GDP of the creative economy for the period 2010-2016.

Principal component analysis (PCA) is a widespread and widely used in various areas of science such as bioinformatics, econometrics, and chemometrics among others. Once that PCA is based in the eigenvalues and the eigenvectors which are a very weak approach to high dimension systems with degrees of sparsity and in these situations the PCA is no longer a recommended procedure. Sparsity is very common in near infrared spectroscopy due to the large number of spectra required and the water absorption broad bands what makes these spectra very similar and with heavy sparsity in matrix dataset, demoting the precision and accuracy, in the multivariate modeling and within projections of data matrix in smaller dimensions. To overcoming these shortcomings the LASSO, a not PCA based method, model was applied to a NIR spectra dataset from Biodiesel and its performance was, statistically, compared with traditional multivariate modeling such as PCR and PLSR.

The COVID-19 pandemic has exacted a tremendous toll on global health and economic stability, significantly affecting families through the loss of loved ones who were primary earners. A phenomenological study was carried out to explore the experience and resilience of families who survived the death of an earning member due to COVID-19 in a selected area of Ganjam. Data were collected through in-depth interviews utilizing a purposive sampling technique with 8 participants from October 20, 2023, to November 6, 2023. NVIVO-14 Free trial version was used for the analysis. The study findings revealed that 62.50% of participants were females aged 31-40, with an equal split between single and married individuals. Notably, 50% were bereaved children of the deceased. A majority, 75%, had achieved higher education and belonged to nuclear families. Hospitalization periods prior to death varied, with income levels largely remaining between Rs 20,001 and Rs 40,000 before and after the loss. All deceased were males, with significant health issues like diabetes mellitus and kidney disease being prevalent. The study identified six major themes-Family Response, Last Ritual, Power Take-up, Relocation, Children and Young Adults, and Family Bereavement Experience-comprising 23 subthemes that encapsulate the complex emotional and logistical challenges faced by the families. These insights highlight the need for more extensive research to better understand and generalize the resilience mechanisms and experiences of similarly affected families.

The COVID-19 pandemic has exacted a tremendous toll on global health and economic stability, significantly affecting families through the loss of loved ones who were primary earners. A phenomenological study was carried out to explore the experience and resilience of families who survived the death of an earning member due to COVID-19 in a selected area of Ganjam. Data were collected through in-depth interviews utilizing a purposive sampling technique with 8 participants from October 20, 2023, to November 6, 2023. NVIVO-14 Free trial version was used for the analysis. The study findings revealed that 62.50% of participants were females aged 31-40, with an equal split between single and married individuals. Notably, 50% were bereaved children of the deceased. A majority, 75%, had achieved higher education and belonged to nuclear families. Hospitalization periods prior to death varied, with income levels largely remaining between Rs 20,001 and Rs 40,000 before and after the loss. All deceased were males, with significant health issues like diabetes mellitus and kidney disease being prevalent. The study identified six major themes-Family Response, Last Ritual, Power Take-up, Relocation, Children and Young Adults, and Family Bereavement Experience-comprising 23 subthemes that encapsulate the complex emotional and logistical challenges faced by the families. These insights highlight the need for more extensive research to better understand and generalize the resilience mechanisms and experiences of similarly affected families.

The purpose of this article is to simulate and analyze the impacts of development interventions on the population of three different sites in Sahelian millet-cropping Niger (Sahelian Africa), taking account the differentiation of social and agro-ecological constraints on the different types of villagers. The work is based on a previous article , which has shown that using an individual Agent-based model (ABM) is a relevant approach to integrate agro-ecological, social and economic characteristics of a system and that family internal rules have strong impacts on village and environment evolutions. Two development project interventions are simulated in a context of no land scarcity: inorganic fertilizers availability for farmers and an inventory credit technique based on millet yields that some villagers may choose to use. Two rationalities are tested, one upon economic values and the second upon the intra-village "reputation" gains. Our results illustrate that a village cannot be considered as a whole and project operators must take in account the precise target population rather than all adult villagers. Project involvements concern only sites where savings for securization or intensification are possible: These proposals need actually some food security and investment capacities that are largely conditioned by family manpower and size. Inorganic fertilizers have little success without any intensification process in a context of good land availability. Inventory credit intervention engages a maximum of 25% of the population in the site with medium agro-ecological conditions. Reputation has little effect on the population behavior and should be considered more as a local wealth estimation factor between villagers. Therefore, one should consider these proposals as a potential support tool for a limited part of the population capable to go beyond the survival level, but not as a global poverty-alleviation panacea.

Os chassis estão incorporados aos sistemas mecânicos veiculares sendo definidos como a estrutura principal de um automóvel, pois nele são acoplados todos os sistemas do veículo, como por exemplo, a suspensão. Os esforços impostos pela suspensão são do tipo dinâmico e decorrem, por exemplo, das irregularidades da pista. O presente trabalho objetiva simular o comportamento estático e dinâmico de um chassi de protótipo automotivo do tipo tubular. É importante a realização dessas análises para conhecer o comportamento da estrutura quando trafegar sobre rodovias. A modelagem por elementos finitos apresenta-se hoje como uma ferramenta indispensável para simular o comportamento da estrutura.

The building sector is a major energy end-use sector globally. Promoting the green transformation of the building sector via green finance instruments (GFIs) is crucial for China to achieve its carbon neutrality goal by 2060. This study develops a system dynamics assessment methodology, simulating the dynamics of various building stocks with different energy efficiencies and quantifying the long-term systemic impact of multiple GFIs on both the new development of green buildings and energy retrofitting of existing buildings. The results show that with the implementation of a combination of GFIs, the amount of energy use reduction in the building sector keeps expanding; while the amount of CO 2 reduction will reach its highest level from 2040 to 2045 and it subsequently declines. Within the GFI mix, the results demonstrate the indispensable role of fiscal subsidies and the critical bridging role of green insurance for the green transformation of the building sector. The systemic effect of the GFI mix is 22.3 % greater than the sum of the effects of constituent individual GFIs. Drawing on these findings, more targeted GFIs for different building types are proposed, and differentiated policies to both building developers and financial agencies are suggested.

At the end of the XIX and the beginning of the XX century there was a considerable industrial development in Portugal, characterized by the flourishing of several industrial plants. Brick masonry chimneys represent some of the most interesting examples of the industrial architectural heritage. The paper shows the case study of a chimney from a former ceramic factory near Porto city and that now is part of a cultural and leisure public park. With the main goal of evaluating the seismic vulnerability of existing structures, numerical models are often used without the proper knowledge of their mechanical characteristics. The focus on this paper is given on the construction of a realistic numerical model based on a detailed in-situ survey of the chimney, involving: geometrical characterization; visual inspection, with damage registration; structural/material assessment, based on in situ dynamic tests. Two different approaches regarding the chimney damage state were followed for the calibration of the numerical model. The models from both approaches were then subjected to accelerograms matching the chimney site conditions and the responses were compared, underlining the importance of a good mechanical characterization of the materials involved.

Understanding the scale and direction of emerging and incumbent vehicle powertrains is critical for accelerating the transition to the green mobility economy. Our aim is to explore the dynamic influences between the conventional, electric and hybrid vehicle powertrains on a global market scale. Based on the Technological Innovation System framework and the Lotka-Volterra model, we argue that a powertrain with positive or negative market growth can both support and inhibit the market growth of the other powertrains. Using Google traffic search data (2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016), our results show that their relationships are not always competitive, but symbiotic, parasitic and amensalism.

The @Corp case study concerns a high-technology manufacturing company. It is based on qualitative and quantitative data collected through interviews and written reports. In this paper, we discuss some of misperceptions shared by the strategic business unit (SBU) management. The SBU managers claimed to know various components of the structure interrelating the information, money, raw materials, workforce, and machinery of their SBUs to the extent that they felt confident in their policy design and could identify the structural causes of unfavorable systems behavior. Yet, the whole company did not perform to expectations. Several important business insights were captured in the system dynamics model and emphasized in the @Corp ILE. The interaction with @Corp ILE is intended to increase the managers' understanding of how individual SBU policies impact the overall performance of the whole business system. In this paper we discuss several advanced learning principles used in the ILE and propose a learning strategy to facilitate management learning.

The formulation and evaluation of renewable energy policies is a burning subject matter all over the globe. Policy makers seek to cautiously perceive information from the renewable energy market place so as to determine the dynamic factors, variables and policy parameters that influence the design of renewable energy policies. The perceived information is often imprecise or fuzzy, which makes policy formulation difficult. This paper presents a framework for evaluating renewable energy policies based on a fuzzy system dynamics (FSD) paradigm. First, we describe the renewable energy policy problem, with a case study example. Second, we present a framework for FSD modeling. Third, we propose a high-level causal loop analysis to capture the complex dynamic interactions among various energy demand and supply factors, from a fuzzy system dynamics perspective. Fourth, and finally, we propose an FSD model for renewable energy policy formulation and evaluation.

The study aims at exploring the technical relationship between extension service provisioning and farm level income among farm households; particularly engaged in paddy and horticultural crops. Extension service can be a game changer in agriculture as it provides livelihood to almost 70 percent of the workforce in Assam. The study is based on primary data which reveals some significant results regarding impact of extension service on farm business income. Though public extension service is still not popular mode of extension, its impact has been found to be significant in raising farm income. However, its penetration is still a major concern.

In this paper, we attempt to invent a new way to understand risk, measure it, and weigh its consequences. We attempt to design a rational process for risk-taking; a process that gives the system dynamicist the ability to define what may happen in the future and then to choose among alternatives.

This study examines the relationship between military expenditures and the frequency of armed conflicts using data from 92 countries over the period 1949 to 2024. Contrary to expectations of a direct linear relationship, the analysis reveals a negligible correlation, challenging the assumption of a causal link between military spending and conflict occurrence. Instead, four distinct security strategy types emerge: superpowers (high expenditures, many conflicts), deterrence strategists (high expenditures, few conflicts), fragile states (low expenditures, many conflicts), and peaceful pragmatists (low expenditures, few conflicts). The findings highlight the importance of geopolitical context and state capacity over absolute military spending in influencing conflict dynamics. This typology provides a nuanced framework for understanding diverse security approaches and underscores the need for context-sensitive policy-making in defense and conflict prevention.

This project deals with management policies toward sustainable development in a wetland. Wetlands are fragile ecosystems and constitute a great potential for economic, cultural, scientific, and recreational value to human life. Conservation and effective utilisation of natural resources can be achieved under sustainable development practices. Achievement of these goals requires well understanding of system under study so a holistic point of view is to be adopted. The geographical location of the region is in Temperate Climate Belt and consists of a shallow lake and its surrounding, an important nesting place for bird species. Fishing is a commercial activity. Ultimate goal of the project is to seek balance between ecosystem and human activities in order to secure a continuous improvement in well-being of the inhabitants while improving or at least maintaining the ecosystem. To this end, a system dynamics model of the wetland system will be constructed to analyse policy alternatives.

This paper investigates two different yet related research questions about stock management in feedback environments. The first purpose is to analyse the effects of selected experimental factors on the performances of subjects (players) in a stock management simulation game. In light of these results, our second objective is to evaluate the adequacy of standard decision rules typically used in dynamic stock management models and to seek improvement formulations. To carry out the research, the generic stock management problem is chosen as the interactive gaming platform. In the first part, gaming experiments are designed to test the effects of three factors on decision‐making behaviour: different patterns of customer demand, minimum possible order decision (‘review’) interval and, finally, the type of receiving delay. ANOVA results of these three‐factor, two‐level experiments show which factors have significant effects on 10 different measures of behaviour (such as max–min range of o...

A dynamic model is built to study the water regulation of human body and related disorders, focusing on the fundamental feedback mechanisms involved in their normal and abnormal physiology. The simulation model is extended to include therapeutic interventions related to the most common body fluid disorder, namely, water intoxication/hyponatremia. The modeling approach is based on system dynamics methodology. Comparisons with experimental and field data show that the model adequately reproduces typical dynamics of the body fluid variables in their normal and diseased states. Finally, an interactive game version is developed to test the possible effects of alternative treatment options on a simulated patient. Simulation and game results reveal the subtleties involved during and after administration of various pharmacological interventions. For example, hypertonic saline should be administered concurrently and in delicate balance with drugs that increase urine flow. The simulator offer...

This research deals with the dynamic simulation modelling of a shallow freshwater lake ecosystem and analysis of potential sustainable management policies. The study region consists of a shallow freshwater lake and its surroundings, where fishing is a major commercial activity. The lake is under high nutrient loads, hence eutrophic with macrophyte dominance. The goal of this research is to find a balance between the ecosystem and economic activities in the region. To this end, a system dynamics model of the wetland is constructed. The results obtained from model simulations show that there is no threat of a shift to algal dominance in the near future. The major problem seems to be a potential decline in the welfare of the inhabitants, mainly due to unsustainable population increase. Different scenario runs reveal that the lake would have become eutrophic with algal dominance, if the crayfish population did not collapse due to a fungus disease in 1986. One particular scenario analysis (the recovery of crayfish sometime in the future within the model time frame) results in increase in crayfish harvest; hence in income from fishing, leading to betterment in social conditions. As for the alternative policies tested, 'improved agricultural techniques' is the only policy that leads to better social conditions, through increased yield per hectare. It is hoped that the dynamic simulation model will serve as a laboratory to study the different features of the eutrophication problem in shallow freshwater lakes and to analyse different policy alternatives with an integrated, systemic approach.

Higher penalties may apply, and higher damages may be awarded, for offences and infringements involving the conversion of material into digital or electronic form. Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong. represent the views of the University of Wollongong. Sundarasaradula, Doy, A thermodynamical perspective on organisations: their structure and evolution,

The aim of this research is to generate a better understanding and an insightful explanation of the nature and characteristics of organisational structure and evolution through the synthesis of thermodynamics and traditional organisational theories. As living systems, formal organisations need specific energy fluxes not only for their existence, but also for change and evolution, which are the key features that enable them to survive and prosper. The synthesis of thermodynamics and traditional organisational theories can be actualised through the application of the theory of dissipative structures and the theory of self-organisation both of which are based upon non-equilibrium thermodynamics. According to these theories, energy flowing through the systems can create temporal order and organisation as well as changes within these systems provided that their logical structure is autocatalytic. In this thesis, a system dynamics model, which is based upon two hypothetical organisation a...

A recent two-period statistical analysis across 150 advanced and developing countries found that 4 to 6 socioeconomic factors were strongly predictive of a country’s life expectancy at birth (LEB); perhaps surprisingly, these did not include GDP per capita as a direct explanatory factor. Some possible next steps were described, one of which was to create a dynamic simulation model that could reproduce and explain historical LEB growth patterns over time for individual countries.  Here I present the first attempt at such a simulation model, including additional data work, overview of the model’s structure, model output for the world’s 15 most populous countries (starting in 2000), analysis of the results, and examples of simulated LEB improvements over time for several potential areas of intervention.