Health-Aware Model-Predictive Control of a Cooperative AGV-Based Production System.

In the paper, a new scheduling strategy for assembly systems consisting of cooperating Automated Guided Vehicles (AGVs) based on their remaining operational time is developed. The operational time is associated with state of charge and state of health of the AGV battery. While the latter is defined as a possible number of repetitions of a set of given tasks, both are impossible to measure on-line directly with conventional sensors. Therefore, a novel state-of-charge estimator is proposed, which uses battery current and voltage sensor readings. In contrast to the approaches presented in the literature, a comprehensive analysis of its convergence is provided. Subsequently, a state-of-health predictor is developed. With the above measures, a new control strategy for cooperative AGVs is proposed. It is achieved by the allocation of alternative tasks among two cooperating robots referring to the state of the accomplished tasks from the previous stage of the assembly process. The proposed method allows a predictive control of assembly processes with several constraints, e.g., productivity of each assembly station, speed of the communication, or operation capability of the robots involved in the assembling process. The final part of the paper shows an experimental study exhibiting the performance of the proposed approach.

Grain quality characteristics and dough rheological properties in Langdon durum-wild emmer wheat chromosome substitution lines under nitrogen and water deficits.

BACKGROUND: Wild emmer wheat could serve as a source of novel variation in grain quality and stress resistance for wheat breeding. A set of Triticum durum-T. dicoccoides chromosome substitution lines [LDN(DIC)] and the parental recipient cv. Langdon grown under contrasting water and nitrogen availability in the soil was examined in this study to identify differences in grain quality traits and dough rheological properties. RESULTS: Significant genotypic variation was found among the materials for studied traits. This variation was also considerably affected by soil treatments and G × E interactions. The substitutions LDN(DIC-1A) and LDN(DIC-1B) showed separate differentiation in the composition of glutenin sub-units. The results indicated that primarily chromosome DIC-6B is stable source of an enhanced grain protein content and advantageous dough rheological properties. Similar features seem to be shown by the substitutions with the DIC-1A, DIC-2A and DIC-6A, but not under nitrogen shortage, when generally a considerable decrease was noticed in the range of genotypic variation in grain quality. CONCLUSIONS: The substitution lines, particularly those with DIC-6B and DIC-6A and to a lesser extent DIC-1A and DIC-2A, were distinguished by advantageous grain quality traits, mixing properties and dough functionality and appear to be the most promising sources of innovative genes for wheat breeding. © 2016 Society of Chemical Industry.

Researching on the Effect of Input Parameters on the Quality and Manufacturability of 3D-Printed Cellular Samples from Nylon 12 CF in Synergy with Testing Their Behavior in Bending.

The study of cellular structures and their properties represents big potential for their future applications in real practice. The article aims to study the effect of input parameters on the quality and manufacturability of cellular samples 3D-printed from Nylon 12 CF in synergy with testing their bending behavior. Three types of structures (Schwarz Diamond, Shoen Gyroid, and Schwarz Primitive) were selected for investigation that were made via the fused deposition modeling technique. As part of the research focused on the settings of input parameters in terms of the quality and manufacturability of the samples, input parameters such as volume fraction, temperature of the working space, filament feeding method and positioning of the sample on the printing pad were specified for the combination of the used material and 3D printer. During the experimental investigation of the bending properties of the samples, a three-point bending test was performed. The dependences of force on deflection were mathematically described and the amount of absorbed energy and ductility were evaluated. The results show that among the investigated structures, the Schwarz Diamond structure appears to be the most suitable for bending stress applications.

Cultivating sustainable environmental performance: The role of green talent management, transformational leadership, and employee engagement with green initiatives.

BACKGROUND: The success of organizations' sustainable performance mainly depends on their human resource capital and for this organizations now need to focus on green human capital development programs including green talent management (GTM). GTM entails attracting, nurturing, and retaining those people who can promote the green initiatives of the organization. OBJECTIVE: This paper aims to investigate the impact of GTM, transformational leadership, and employee engagement on the sustainable environmental performance of organizations. METHODS: The data were collected from both academic and administrative employees in five Omani higher education institutions (HEIs). In total 367 questionnaires were collected using drop-off and pickup methods. RESULTS: The results of the study showed that green hard and green soft talent management (TM) and employee engagement with green initiatives are significant predictors of the sustainable environmental performance of HEIs. Moreover, transformational leadership can moderate the influence of green soft TM on employee engagement with green initiatives by strengthening the relationship. CONCLUSIONS: For sustainable performance and development, organizations especially HEIs need to actively assume their social responsibilities and implement sustainable environmental management. The present study provides meaningful implications for practitioners, educational policymakers, and leaders to promote GTM and employee engagement for sustainable environmental performance. Supporting green skill development, engaging employees with green initiatives, and promoting staff with green skills can help organizations particularly HEIs to increase their sustainable environmental performance and gain a competitive advantage.

Decision Making in Health Management during Crisis: A Case Study Based on Epidemiological Curves of China and Italy against COVID-19.

In December 2019, a new infectious respiratory disease called COVID-19 was identified in Wuhan, Hubei province, in China and quickly reached pandemic status in March 2020, in uncertain and frightening situation. The objective of this study was to analyze the epidemiological curves from the fight against COVID-19 in China and Italy, establishing parameters that can assist with the decisions of health-planning managers. This study was conducted using the principles of the grounded theory methodology and a practical method of comparison between the real and ideal curves, based on the contamination and death data by SARS-CoV-2 in China and Italy. For this purpose, we built graphs, including parameters, such as, among others, amplitude, height, saturation point, acceleration, lethality, event, risk, and efficiency. The results of our study showed that China exhibited amplitude and height of the active contamination and death curve 2 times smaller than those of Italy which exhibited several saturations. It was investigated that Italy presented a qualitative risk of 5-6, whereas for China it was 4. According to the parameters, China and Italy presented health management that was able to reduce the impact caused by the virus. The implementation of adequate health management with these practical tools can guide perception of the crisis critical levels, avoiding major disasters. We intend to continue to validate the method in the analysis of data from Brazil and the USA.

A bounded-error approach to actuator fault diagnosis and remaining useful life prognosis of Takagi-Sugeno fuzzy systems.

The paper presents an actuator fault diagnosis and prognosis scheme for Takagi-Sugeno fuzzy system. It overcomes the drawbacks of the approaches presented in the relevant literature by taking into consideration the problem of the robustness. The proposed approach consists of an actuator fault estimator which provides knowledge about faults with their uncertainty intervals. Thus, the fault detection mechanism relies on an acceptable threshold imposed on these intervals. Once the fault is detected, the remaining useful life of an actuator is predicted what is expressed in the so-called time-to-failure. Similarly as in the case of fault estimation, the remaining useful life is provided as an uncertainty interval. It should be notated that previously reported approaches to Takagi-Sugeno systems cannot either provide the uncertainty of fault estimates for remaining useful life. To tackle the development of the above schemes the theory of quadratic boundedness and feasible parameter set-based estimation are employed. The final part of the paper portrays a case study which clearly exhibits the performance of the proposed approach.

An investigation of safety design practices of metal machines.

BACKGROUND: Machinery safety issues are a challenge facing manufacturers who are supposed to create and provide products in a better and faster way. In spite of their construction and technological advance, they still contribute to many potential hazards for operators and those nearby. OBJECTIVE: The aim of this study is to investigate safety aspects of metal machinery offered for sale on Internet market according to compliance with minimum and fundamental requirements. METHODS: The study was carried out with the application of a checklist prepared on the basis of Directive 2006/42/EC and Directive 2009/104/EC and regulations enforcing them into Polish law. RESULTS: On the basis of the study it was possible to reveal the safety aspects that were not met in practice. It appeared that in the case of minimum requirements the most relevant problems concerned information, signal and control elements, technology and machinery operations, whereas as far as fundamental aspects are concerned it was hard to assure safe work process. CONCLUSIONS: In spite of the fact that more and more legal acts binding in the Member Countries of the European Union are being introduced to alleviate the phenomenon, these regulations are often not fulfilled.