Search results

This study aims to identify the most relevant causal factors and the feedback loops of the dynamics between Tuta absoluta incidence in tomato crops and farmers' reactions to the problem. The authors seek to develop a conceptual model based on farmers' know-how to address crop damage by T. absoluta at a local and regional levels in order to determine how to confront this problem in the tomato-growing region of Sáchica, Colombia.

Community-Based System Dynamics (CBSD) is a participatory research methodology in which a group of stakeholders identifies relevant variables and the cause-effect relations among them which are then arranged into a causal loop diagram. The authors implemented this methodology in a workshop, focused on the farmers' insights related to the pest situation at the local and regional level, to achieve a causal loop diagram that explained pest dynamics and their potential management.

The relevant factors for the presence of T. absoluta, seen in the causal loop diagram, vary regionally and locally. At the local level, the pest impacts tomato production, farmers' well-being and their cash flow, while at the regional level, it affects market dynamics and environment and promotes regional coordination among farmers. Farmers propose product innocuity as a key regional objective. They also proposed establishing a planting calendar and census of greenhouses to control the pest throughout the region and the tomato supply.

First, the synthesized model could not be validated with the farmers due to the COVID 19 epidemic. However, the authors held sessions with experts to analyze each result. Second, decision-makers from the local government did not participate in the workshop. Nevertheless, the approach of the workshop was aimed at understanding the mental models of the farmers since they are the ones who decide how pests are managed. Finally, even though farmers showed interest in projects aimed at proposing area-wide, long-term and wide pest control strategies, there is a risk that they will not adopt the proposed changes, due to risk aversion.

CBSD has not been applied to agricultural systems to analyze impacts from pests at the local and regional levels. The results of this study contribute to designing future interventions for pest control in the region, along with the factors which may turn out to be “side effects” or unwanted results. To design pest control interventions at a regional level, a sound understanding of the variables or factors that control the system dynamics at various levels is required. This study represents the first step towards that end.

In Latin America and the Caribbean, the access of students to higher education has presented an extraordinary growth over the past fifteen years. This rapid growth has presented a challenge for increasing the system resources and capabilities while maintaining its quality. As a result, the networked universities (NUs) organized themselves as a collaborative network, and they have become an interesting model for facing the complexity driven by globalization, rapidly changing technology, dynamic growth of knowledge and highly specialized areas of expertise. In this article, we studied the NU named Red Universitaria Mutis (Red Mutis) with the aim of characterizing the collaboration and integration structure of the network.

Network analytic methods (visual analysis, positional analysis and a stochastic network method) were used to characterize the organizational structure and robustness of the network, and to identify what variables or structural tendencies are related to the likelihood that specific areas of a university would collaborate.

Red Mutis is a good example of regional NUs that could take advantage of the strengths, partnerships, information and knowledge of the regional and international universities that form the network. Analyses showed that Red Mutis has a differentiated structure consisting of academic and non-academic university areas with a vertical coordination (by steering and management) of the different university areas.

The methodology could be used as a framework to analyze and strengthen other strategic alliances between universities and as a model for the development of other NU in local and global contexts.

The purpose of this paper is to evaluate Chinese indirect trade relations in the global trade network to observe if the objectives identified by Cai (2017) in the Belt and Road Initiative (BRI) are being fulfilled, especially with Latin America and the Caribbean (LAC) countries.

Using data from the UNCTAD (2016) for the period 2011–2015, a normalized exports network is built. It is analyzed with the Forgotten Effects Theory and the PageRank algorithm. A Monte Carlo experiment with 10,000 replicates is performed to account for its volatility.

The paper identifies one instance in which China's peripheral countries are importing raw materials and commodities -–oil products – to produce low technological value-added products, which, in turn, are exported to China. LAC countries do not have significant indirect trade relations with China when the former is the origin country, while the latter is the destination in a trade relationship. The trade network has a clear core-periphery structure, with China belonging to its core, although being only the fourth most central node in the network.

This paper contributes with both a new methodology for the analysis of indirect trade relations and the results found for China under the BRI and its trade relationship with LAC economies.

This study deals with the computational simulation and inverse analysis of the cooling treatment of the hypoxic-ischemic encephalopathy in neonates. A reduced-order model is implemented for real-time monitoring of the internal body temperatures. The purpose of this study is to sequentially estimate the transient temperatures of the brain and other body regions with reduced uncertainties.

Pennes’ model was applied in each body element, and Fiala’s blood pool concept was used for the solution of the forward bioheat transfer problem. A state estimation problem was solved with the Sampling Importance Resampling (SIR) algorithm of the particle filter method.

The particle filter method was stable and accurate for the estimation of the internal body temperatures, even in situations involving large modeling and measurement uncertainties.

The proposed reduced-order model was verified with the results of a high-fidelity model available in the literature. Validation of the proposed model and of the solution of the state estimation problem shall be pursued in the future.

The solution of the state estimation problem with the reduced-order model presented in this paper has great potential to perform as an observer of the brain temperature of neonates, for the analysis and control of the systemic cooling treatment of neonatal hypoxic-ischemic encephalopathy.

The main treatment for hypoxic-ischemic encephalopathy in neonates is the cooling of affected regions. Accurate and fast models might allow the development of individualized protocols, as well as control strategies for the cooling treatment.

This paper presents the application of the SIR algorithm for the solution of a state problem during the systemic cooling of a neonate for the treatment of the hypoxic-ischemic encephalopathy.

The purpose of this paper is to characterize the situation in the Spanish banking industry through the identification of strategic groups based on a set of variables.

To do so, the authors use a 13-year data set and a time inhomogeneous hidden Markov model (HMM) in which the time variable transition matrix captures institutions’ group switching behavior to identify these strategic groups. In fact, the authors consider a mixture model is the data generation process.

Two groups are identified. These groups are primarily characterized by size and other strategic variables. The probability of remaining in a group is generally high: 87.28 per cent for SG1 and 61.84 per cent for SG2. The probability of switching groups is low: 12.72 per cent probability of switching from SG1 to SG2 and 38.16 per cent probability of switching from SG2 to SG1. Banks in SG1 seem more stable over time; they have low levels of switching behavior and well-defined long-term behavior. Banks in SG2 seem to evolve in terms of group membership.

Using an inhomogeneous HMM with time-variable transition matrix, this paper allows for time-varying parameters in the distributions to analyze the evolution of strategic group membership in this industry to detect changes in group strategy, changes in membership and the stability of groups over time.

The purpose of this paper is to present the innovation management program (IMP) (FAZ Program) and analyze its results according to the public policy goals that support it (Pró-Inova) suggesting improvements.

Intensive-direct-observation method in 43 companies; systematic data gathering and analysis (172 meeting documents); and innovation maturity diagnostics in 30 companies between August 2013 and May 2016.

The FAZ Program success rate according to the Pró-Inova goals achieved 81 percent. The percentage of completion of FAZ activities decreases during its implementation from 100 percent (strategic module) to 74 percent (management module) and ending at 46 percent (project module). The maturity for innovation of these committees/teams is decisive for those percentages. Companies whose maturity for innovation of the strategic committee and the organizational team are above average or excellent have, respectively, 1.8 and 1.7 times greater probability of implementing the program successfully.

The FAZ Program represents only 4 percent of the programs supported by Pró-Inova. The innovative products, processes and businesses produced by the FAZ Program implementation are not measured. These innovations usually happen several years after an innovative management models implementation.

The maturity for innovation diagnosis is useful both to evaluate the company’s innovation capacity and to predict its chances of implementing the program successfully. Adjusting the structure of the model (e.g. PDCA cycle for the organizational module) and improving the program’s implementation (e.g. ensure management module resources and maturity for innovation capacity) can increase the program’s success rate.

Previous research works on IMPs supported by Pro-Inova focus on describing their methodology or benefits. The results allow answering what and how one of these programs offers in a return to the public innovation support received.

One of the main difficulties for wine managers is understanding and interpreting how some strategies and company behaviours could affect firms’ performance. This study aims to contribute to improve these concerns by examining the evolution of the competitive wine industry structure over time using the strategic group membership dynamics approach.

This study empirically analyses a data set spanning the period 2004–2014 to identify the strategic groups in the Spanish wine industry and to model their evolution over time. A time inhomogeneous hidden Markov model (HMM) is used for this purpose.

Three strategic groups are identified: Young Makers, Quality Lovers and Major Players. Young Makers are small wineries that produce low-quality wines. They are not part of a collective brand – Protected Designation of Origin – and do not invest in marketing campaigns. Quality Lovers produce the highest quality wines but offer a narrow assortment. They invest modestly in advertising, and most of them belong to a Protected Designation of Origin. Major Players produce medium-quality wines, offer a wide assortment and invest heavily in advertising. The groups seem stable over time.

The results show that strategic group analysis can be used to identify and compare patterns of strategic activity within the wine industry, providing a better understanding of the competitive environment.

No previous studies have analysed the competitive structure of the Spanish wine industry. This study delineates the structure of this industry using strategic groups, which is supported by a valid econometric model. Therefore, from a theory base perspective, this study adds new evidence to the stream of research on strategic groups by investigating their evolution over time in the wine industry and the effect of strategic group membership on performance.

The process by which disabled individuals become entrepreneurs can be influenced by factors of different orders. Throughout their entrepreneurship careers and projects, disabled entrepreneurs may have to overcome multiple personal, social and political barriers. This study aims to review what we do (and do not) know about disabled entrepreneurs research to date.

The literature review focused on analyzing 42 articles from two databases, namely, Web of Science and Scopus. After the articles were selected, they were grouped into thematic clusters.

The results were categorized into four areas, namely, entrepreneurs with disabilities, self-employment as an alternative to unemployment for people with disabilities, barriers faced by disabled entrepreneurs and the importance of education, training and/or orientation for these individuals’ entrepreneurship. The research verified that, in some cases, people with disabilities resort to self-employment and become entrepreneurs to avoid unemployment. Education and training’s positive role in how this process develops is clear as they empower individuals with disabilities and enable them to raise entrepreneurial attitudes.

Based on the citation profile of articles on disabled entrepreneurs, the results contribute to a better understanding of the flow and main findings of scientific research on this topic over the past 15 years. The findings also include research tendencies that reveal the field’s emergent perspectives, which are of great importance to academics seeking to enhance entrepreneurial processes and policymakers interested in stimulating entrepreneurship education.

This study aims to formulate a mechanism design in the derivatives market, summarizing a framework to set up the Brazilian electricity futures market.

This exploratory study formulates a mechanism design in the derivatives market, summarizing a framework to set up the Brazilian electricity futures market.

The results show a positive economic outcome for the creation of the Brazilian futures electricity market.

The main feature in this work is to summarize a framework to set up the Brazilian electricity futures market applying mechanism design, applicable in other countries. The features of the mechanism are the space of expected results (Z), the strategies to survey the environmental space (θ) and the mechanism design – messages space (M).