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The objective of this paper is to propose a methodology based on random demand inventory models and dependence structures for a set of raw materials, referred to as “components”, used by food services that produce food rations referred to as “menus”.

The contribution margins of food services that produce menus are optimised using random dependent demand inventory models. The statistical dependence between the demand for components and/or menus is incorporated into the model through the multivariate Gaussian (or normal) distribution. The contribution margins are optimised by using probabilistic inventory models for each component and stochastic programming with a differential evolution algorithm.

When compared to the non-optimised system previously used by the company, the (average) expected contribution margin increases by 18.32 per cent when using a continuous review inventory model for groceries and uniperiodic models for perishable components (optimised system).

The multivariate modeling can be improved by using (a) other non-Gaussian (marginal) univariate probability distributions, by means of the copula method that considers more complex statistical dependence structures; (b) time-dependence, through autoregressive time-series structures and moving average; (c) random modelling of lead-time; and (d) demands for components with values equal to zero using zero-inflated or adjusted probability distribution.

Professional management of the supply chain allows the users to register data concerning component identification, demand, and stock levels to subsequently be used with the proposed methodology, which must be implemented computationally.

The proposed multivariate methodology allows it to describe demand dependence structures through inventory models applicable to components used to produce menus in food services.

Este trabajo propone una metodología basada en modelos de inventarios con demanda aleatoria y estructura de dependencia para un conjunto de materias primas, denominadas “componentes”, usadas por servicios de alimentación que producen raciones alimenticias denominadas “menús”.

Los margen de contribución de servicios de alimentación que producen menús son optimizados empleando modelos de inventarios con demandas aleatorias dependientes. La dependencia estadística entre demandas de componentes y/o menús es incorporada en el modelado mediante la distribución gaussiana (o normal) multivariada. La optimización de los márgenes de contribución se logra usando modelos de inventarios probabilísticos para cada componente y programación estocástica mediante el algoritmo de evolución diferencial.

El margen de contribución esperado (promedio) aumenta en un 18,32% usando modelos de inventario de revisión continua para abarrotes y modelos uniperiódicos para componentes perecederos (sistema optimizado), en relación al sistema no optimizado usado anteriormente por la compañía.

La metodología multivariada propuesta permite describir estructuras de dependencia de la demanda mediante modelos de inventario aplicables a componentes usados para producir menús en servicios de alimentación.

Una administración profesional de la gestión de la cadena de suministros permite registrar datos de la identificación del componente, su demanda y sus niveles de stock para ser usados posteriormente con la metodología propuesta, la que debe estar implementada computacionalmente.

El modelado multivariado puede ser mejorado (a) utilizando distribuciones probabilísticas univariadas (marginales) distintas a la gaussiana, mediante métodos de cópulas que recojan estructuras de dependencia estadística más complejas; (b) considerando demandas de componentes con valores iguales a cero, mediante distribuciones probabilísticas infladas en cero; (c) usando dependencia temporal, mediante estructuras de series de tiempo autorregresivas y de media móvil, y (d) modelando el lead-time en forma aleatoria.

This paper aims to propose a supply model of periodic review with joint replenishment for multi-products grouped by several variables with random and time dependence demand.

The products are grouped by multivariate cluster analysis. The stochastic inventory model describes the random demand of each product, considering the temporal dependency through a generalized autoregressive moving average model. Stochastic programming for the total cost of inventory is obtained considering the expected value of the demand per unit of time.

The total costs for the products grouped with the proposed model are 6% lower than for the individual inventory policy. The expected shortage units decrease significantly in the proposed grouped model with temporary dependence. In addition, the proposal with temporary dependency has lower costs than when the independent and identically distributed demand is considered.

The proposed policy is exemplified with real-world data from a Chilean hospital, where the products (drugs) are segmented by grouping variables, forming clusters of drugs with homogeneous behavior within the groups and heterogeneous behavior between groups.

This paper aims to describe relationships between constructs adapted to the pharmaceutical field with respect to the measurement of the supply chains strategic and operational performance in private pharmacies, relating it to the quality of service perceived by users.

Relationships among the indicated constructs were validated through the use of structural equation models. This study includes the use of questionnaires adapted and applied to suppliers (pharmaceutical chemists and supply staff), operational managers (pharmacy assistants) and users (patients and clients) who visit different segments of pharmacies, such as chain businesses and independents located in the region of Valparaíso, Chile. The sample collected information from 128 establishments and 601 people, through which different relationships between segments were compared.

A structural model was validated on the basis of statistical principles. Furthermore, positive relationships were observed in the constructs studied where pharmacy chains had a statistical significance of less than 5 per cent between the responsibility of the supply process and the experience of the users, whereas independent pharmacies had a very significant causal relationship between operational managers and users.

The proposal can help predict the quality of service perceived by the user based on the behavior of sales and supply staff, which may be similar in other markets with similar characteristics.

The structural model proposed is original and adapts measurement scales validated from previous studies to be able to apply them in the pharmaceutical retail market.

The purpose of this paper is to describe how sol‐gel synthesised silica particles are used to modify the characteristics (especially the thermal and mechanical properties) of either an epoxy resin (ER) or a −COOH‐functionalised ER (FER) substrate. In the systems studied here, spherical silica particles are embedded in ER or FER thermosetting polymeric substrates for producing translucent solid materials. There arise covalent unions between the SiO₂ silanol surface groups of the particles and the functionalised FER ends, thus rendering SiO₂‐FER core‐shell compounds.

The characterisation results confirm the affinity existing between ER and SiO₂ particles as well as the existence of chemical bonds at the interface between the silica and FER phases.

An efficient and durable application against corrosion of metallic materials has been developed through the preparation and application of thin surface films made of finely disseminated SiO₂ colloidal particles, which are trapped inside either FER or unfunctionalised ER epoxy resin polymer networks. The results of this test indicate that the anticorrosive performances of FER, SiO₂‐ER and SiO₂‐FER coating films are higher than that related to the ER coating alone.

These silica/ER hybrid materials can be employed as anticorrosive coatings of metallic substrates in commercial appliances, industrial devices and protection of artistic works, such as metal sculptures.

Preparation of organic‐inorganic hybrid materials of enhanced thermal and mechanical properties against corrosion. Functionalisation of an ER polymer network resulted in the improvement of the anticorrosive properties of the sole ER of departure while showing very good corrosion endurance.

This research aims to contribute to History of Education Studies as well as to New Cold War Studies, by examining a Reactor Technology Specialist Engineer program, launched in Hungary three times in the 1980s for Cuban nuclear engineers, graduates of the University of Havana.

The institutional setting, the content of the program, the teaching staff, the students, and the outcomes are studied. The factors that motivated the birth of this special program are examined, including the following areas; in what ways it was different from the courses in which foreign students participated in Hungary; what its strengths and weaknesses were; how we can learn from this past experience and what relevance it has for the present.

The analysis – carried out within the context of Cuban–Hungarian relations in the Cold War – demonstrates that these two satellite countries used the fields of science and education to widen their international possibilities and at the same time to reinforce their national interests by cooperating with each other.

The investigation is based on archival sources, university yearbooks and journals as well as contemporary Hungarian press. Written sources were complemented by interviews with Cuban students and Hungarian teaching staff, thus providing a personal perspective, balancing official views.

This study aims to analyze the relationship between the adherence to critical chain project management (CCPM) practices and the new product development performance, in terms of the results of product development programs and product portfolio management (PPM).

A survey was conducted with 79 innovative companies operating in Brazil. Data were analyzed using correlation analysis and non-parametric tests.

Significant and positive correlations were found between CCPM adoption and the performance factors proposed. The adoption of CCPM offered stronger correlation with PPM performance than with the adoption of traditional methods. The results further indicate a possible indirect contribution of CCPM practices to the product development program by means of PPM improvement.

This study deepens the knowledge of the joint study between project management and new product development, by bringing empirical evidence that the adoption of specific practices suggested by CCPM is used by organizations with superior performance. Moreover, the results broaden CCPM literature by attesting that companies do not necessarily have to apply the CCPM approach in a formal and explicit way to obtain the performance results given. The analyses still have practical value when indicating which CCPM practices should be prioritized by managers seeking high performance in PPM.

The purpose of this study is to explore and conducts a critical literature review to answer a fundamental question in the industrial district literature: are clusters and industrial (clusters/IDs) driving sustainability innovation? By intersecting different yet related strands of literature, the authors take stock of what the authors know about sustainability innovation in clusters/IDs.

This paper reviews the literature for conceptualizing sustainability innovation in clusters/districts.

Insights point out that the sustainability innovation process (development and diffusion) in clusters/IDs and their firms couples into mainstream cluster/IDs framework; clusters/IDs enable sustainability innovation through usual mechanisms, fostering collective change toward sustainability innovation, vis-à-vis other settings and strengthening firm sustainability innovation and performance. Sustainability innovation in clusters/IDs requires coupling different multi-scalar institutional systems effectively, and the cooperation of local organizations and policymakers for co-designing dedicated policies. Collective actions are important and firm heterogeneity needs to be considered in the clusters/IDs framework.

This study is original because it provides state-of-the-art on sustainability innovation in clusters/districts, enabling the topic to advance in this direction.

The purpose of this paper is to analyze the state of the art in Critical Chain Project Management (CCPM), outlining the CCPM literature to date, in an effort to guide future studies.

The paper is based on a bibliometric analysis using Scopus and Web of Science databases. The authors identified the principal journals, articles and authors regarding the research theme, as well as the authors elaborated co-citation and co-occurrence network maps to support the analysis.

The authors described five co-citation clusters: Fundamentals of Critical Chain, Scheduling, Operations Research, Multi-project and Network, and General Project Management. The most frequently occurring keywords were: “project management,” “critical chain,” “scheduling” and “theory of constraints.” Observing the distribution, the expression “project management” occupied a central position, connecting two other clusters, represented by the keywords “scheduling” and “critical chain.” The authors proposed an evolutive framework for the CCPM state of the art in three stages, according to the most frequent topics identified: Conceptual, Deepening of Applications and Methodological Maturity.

This research adopts a systematic approach based on bibliometric tools, which allows a more rigorous organization of the literature. Co-citation and keyword co-occurrence maps provide evidence of how the main themes in CCPM relate. Besides, the presented historical framework allows new research in CCPM to be directed to the most recent topics of interest that have gaps to be explored.

The concept of sustainable development (SD) is a popular response to society’s need to preserve and extend the life span of natural resources. One of the 17 goals of the SD is “education quality” (Fourth Goal of Sustainable Development [SDG-4]). Education quality is an important goal because education is a powerful force that can influence social policies and social change. The SDG-4 must be measured in different contexts, and the tools to quantify its effects require exploration. So, this study aims to propose a statistical model to measure the impact of higher education online courses on SD and a structural equation model (SEM) to find constructs or factors that help us explain a sustainability benefits rate. These proposed models integrate the three areas of sustainability: social, economic and environmental.

A beta regression model suggests features that include the academic and economic opportunities offered by the institution, the involvement in research activities and the quality of the online courses. A structural equation modelling (SEM) analysis allowed selecting the key variables and constructs that are strongly linked to the SD.

One of the key findings showed that the benefit provided by online courses in terms of SD is 62.99% higher than that of offline courses in aspects such as transportation, photocopies, printouts, books, food, clothing, enrolment fees and connectivity.

The SEM model needs large sample sizes to have consistent estimations. Thus, despite the obtained estimations in the proposed SEM model being reliable, the authors consider that a limitation of this study was the required time to collect data corresponding to the estimated sample size.

This study proposes two novel and different ways to estimate the sustainability benefits rate focused on SDG-4, and machine learning tools are implemented to validate and gain robustness in the estimations of the beta model. Additionally, the SEM model allows us to identify new constructs associated with SDG-4.

The purpose of this study was to determine the association between intrinsic capacity (IC) and dynapenia in older adults in outpatient clinics at the Naval Medical Center.

The study design was observational, analytical and retrospective. The study from which the collected data came was an observational analytical cohort, whose main objective was to describe the factors associated with frailty in older adults. The population comes from the Peruvian Naval Medical Center. This was a retrospective, observational, analytical study of the factors associated with frailty in older adults from the Naval Medical Center of Peru.

Data from 1667 participants was analyzed, 682 of them were female (40.9%) and 985 were male (50.1%); regarding age, most participants had 71–80 years (n = 761, 45.6%). Prevalence of the dynapenia was 34.5% (n = 576), and 80.08% (n = 1335) had an altered IC. In an adjusted model using Poisson regression, a prevalence ratio of 2.76 (95%, CI 2.06–3.70) was found. In conclusion, there is an association between IC and dynapenia in older adults.

In Latin America and Peru, there is limited information regarding this topic and tools for the evaluation of IC.