Search results

This study aims to develop two piezoelectric textile devices formed from different weft knitted fabric rapports (Jersey and Pique) to be applied in the renewable energy’s (RE) area.

Two different weft knitted rapports were produced with polyester (PES). The device developed has five layers: a central of poly(vinylidene fluoride) (PVDF) nonwoven, involved by two insulating layers of PES knitted fabric; and two conductive external layers, made of polypyrrole-coated PES knitted fabric. The piezoelectric textile devices were joined by sewing the five layers of the device.

The FTIR technique confirmed the β-phase in the PVDF nonwoven. This study produced and tested two different textiles devices with piezoelectric behavior, confirmed by the correlated pattern of voltage and tensile stress difference curves, showing the potential application in RE’s and sustainable energies field as smart textiles, such as devices incorporated in garments in the areas of high movement (elbow, knee, foot, fingers and hands, among others), and as an energy generator device

Textile materials with piezoelectric properties promise to advance RE’s developments due to their high material flexibility and sensitivity to the electrical response. The knitted fabric technology presents flexibility due to its construction process. Comparative studies analyzing the electrical response between knitted and woven fabrics have already been realized. However, there is a gap in terms of research scientific research regarding the comparison of the piezoelectric effect in a material that presents different knitted fabric rapports.

The purpose of this research is to determine the convenience of using a contract model as an integration mechanism for decision-making in a decentralized supply chain of small agricultural producers in a developing country, taking as hypothesis coordinated chain achieves better management. The analysis is based on information obtained by direct inquiry to 99 small producers in the region, about planning, production, marketing and distribution in the chain, supplemented with secondary information sources.

As a methodology an analysis of maturity in the chain based on the Capability Maturity Model Integration is done, whose evaluation is later analyzed as a fuzzy logic model, with the support of the fuzzy logic of the MATLAB toolbox, to study the convenience of the use of the contract against the other mechanisms, and to establish an approximation to the level of readiness of the chain toward integration.

Results obtained show that the small farmer supply chain studied, from a maturity perspective, has a strong disposition for the use of contracts as an integration mechanism.

The supply chain for small producers presents a high dispersion, little consolidated offer capacity and lack of coordination. Limitations in terms of information and criteria unification are a challenge for future research. Results have socioeconomic implications for small producers and can serve as a guide to formulate policies by the governments in Latin American countries.

As practical implications, it can be stated that the use of supply contracts is a real mechanism that can be implemented in this type of chain, to break the mistrust between the echelons and improve the supply chain performance. This research will allow to establish support programs from local governments for the sustainability and improving income of small producers. In addition, contracts will allow to formalize the linkage of small producers to a sustainable commercial network.

Small agricultural producers in developing countries live in unfavorable conditions, with socioeconomic limitations. This work offers an alternative for their productive activity development that will allow them access to marketing chains in a safe way and improve their living conditions.

Previous studies related to the maturity toward the chain integration and fuzzy logic as a hybrid methodology, were not found in the literature, and less even applied to a chain of small agricultural products.

This paper aims to present a detailed description of Tukuchiy, a framework to dynamically generate adapted user interfaces. Tukuchiy is based on Runa-Kamachiy, a conceptual integration model that combines human–computer interaction (HCI) standards to create user interfaces with user-centered concepts usually addressed by adaptation.

The first step was the definition of three profiles: user, context and interface. These profiles contain information, such as user disabilities, location characteristics (e.g. illumination) and preferences (e.g. interface color or type of system help). The next step is to define the rules that ensure usability for different users. All of this information is used to create the Tukuchiy framework, which generates dynamic user interfaces, based on the specified rules. The last step is the validation through a prototype called Idukay. This prototype uses Tukuchiy to provide e-learning services. The functionality and usability of the system was evaluated by five experts.

To validate the approach, a prototype of Tukuchiy, called Idukay, was created. Idukay was evaluated by experts in education, computing and HCI, who based their evaluation in the system usability scale (SUS), a standard usability test. According to them, the prototype complies with the usability criteria addressed by Tukuchiy.

This work was tested in an academic environment and was validated by different experts. Further tests in a production environment are required to fully validate the approach.

Tukuchiy generates adapted user interfaces based on user and context profiles. Tukuchiy uses HCI standards to ensure usability of interfaces that dynamically change during execution time. The interfaces generated by Tukuchiy adapt to context, functionality, disabilities (e.g. color blindness) and preferences (usage and presentation) of the user. Tukuchiy enforces specific HCI standards for color utilization, button size and grouping, etc., during execution.

The objective of inventory management models is to determine efficient policies for managing the trade-off between customer satisfaction and the cost of goods. This chapter presents a methodology that uses the Monte Carlo Method (MCM) to estimate the behavior of a raw material supply model, considering uncertain variables such as demand, prices, and exchange rates. In order to show how to use this methodology, we analyze the case of a Colombian company in the aluminum industry. This company imports aluminum sheets from China. In this case, we analyze the financial impact of the raw material supply contract proposed by the Chinese supplier. The model considers different supply scenarios for the raw material. We calculate robust indicators such as Value at Risk (VaR), the Conditional Value at Risk (CVaR) and the probability of success for each scenario analyzed. Finally, we conduct a sensitivity analysis with respect to the sales price to validate the proposed models and solution approaches. The results show that considering risk metrics to evaluate the impact of endogenous factors over the supply process is a useful approach to improve decision-making related to this process and also can help to ensure the profitability of the company.

Fashion brands are under heavy criticism for often exhibiting poor working conditions and producing environmental damage. Pressure comes from initiatives such as Fashion Transparency Index (FTI) by Fashion Revolution to assess fashion brands' transparency based on information publicly disclosed. But an understanding of how such movements reflect in a Global South country characterised by institutional voids is still absent.

While the FTI ranks individual brands, in this study the authors have analysed 305 documents extracted from the websites of 20 Brazilian fashion brands to unpack practices and re-bundle them according to three archetypes – opaque, translucent and transparent – that display a maturity curve.

The authors show that advancement is heterogeneous, and we complement previous research exposing the limits of an NGO in driving transparency by investigating a context embedded in institutional voids. The authors show that most fashion brands restrict transparency to tier-1 suppliers. Moreover, although fashion brands increasingly demand disclosure from their suppliers, they do not clarify their own purchasing practices such as cancellation and payment policies. On the positive note, the authors show that maturity for transparent brands can include the actionability concept by engaging with consumer via surveys and educative content.

The authors contribute to theory by offering a maturity curve of fashion supply chain transparency. The authors contribute to practice by offering the three archetypes – opaque, translucent and transparent. This study unveils heterogeneity and asymmetry between the levels of transparency that buying firms demand from their suppliers against what they provide about their own practices.

Are the social domains of kinship and business on balance complementary or contradictory? Do ventures that invest heavily in both – conventionally referred to as “family firms” – bear a net gain or net loss? We are scarcely the first to raise these questions. How then will we try to contribute to an answer? We try this in five ways, all of them based on previous literature. First, we develop the dichotomy of kinship and business by taking seriously the metaphor of yin and yang, merging it with the anthropological constructs of structural domains such as “domestic” and “public.” This metaphor proves to shed light on the relevant literature. Second, we provide a qualitative survey of the costs and benefits of kinship in business. Third, we summarize the empirical work that addresses the performance outcomes from family involvement. Fourth, we consider the practitioner implications of these studies. Finally, we ask if scholars are as yet in a position to answer these questions.

We examine the effect of increasing online job vacancies on labor market efficiency in the context of a developing country. The findings suggest that the rise in online job vacancies has enhanced labor market efficiency by improving the match between job seekers and employers. This hypothesis is supported by an increase in the hiring and net employment growth rates. The study shows a reduction in the vacancy rate in segments of the labor market, with a significant share of vacancies posted online, after implementing a policy requiring firms to report vacancies to the Public Employment Service in Colombia. The results from a Beveridge Curve estimation imply a 1.2 percentage point (pp) decrease in the vacancy rate for a given unemployment rate and increments in the hiring and employment growth rates of 1.1pp and 1.3pp after the policy change, respectively. These results support the notion that policies to reduce information barriers can improve labor market performance.

This chapter looks at how Latin American immigrants go about shopping for groceries in Nashville, Tennessee, and relates this simple act to a wider political economy. The chapter examines the act of shopping for groceries and the immigrants' preferences through elements largely ignored by the prevailing economic paradigm. To some extent, the immigrants are aware that their mode of shopping is not entirely “rational” and that their choices are often informed by nothing more than “feelings” toward a place or product. The ethnography examines how the immigrants deal with their now dislocated practice of shopping in their everyday life in the new city. In examining this process, the ethnography considers the public spaces in which the practice of shopping takes place, and includes both those stores catering directly to immigrants and those serving a wider market.