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Taking robotic patents between 1977 and 2017 and building upon the topic modeling technique, we extract their latent topics, analyze how important these topics are over time, and how they are related to each other looking at how often they are recombined in the same patents. This allows us to differentiate between more and less important technological trends in robotics based on their stage of diffusion and position in the space of knowledge represented by a topic graph, where some topics appear isolated while others are highly interconnected. Furthermore, utilizing external reference texts that characterize service robots from a technical perspective, we propose and apply a novel approach to match the constructed topics to service robotics. The matching procedure is based on frequency and exclusivity of words overlapping between the patents and the reference texts. We identify around 20 topics belonging to service robotics. Our results corroborate earlier findings, but also provide novel insights on the content and stage of development of application areas in service robotics. With this study we contribute to a better understanding of the highly dynamic field of robotics as well as to new practices of utilizing the topic modeling approach, matching the resulting topics to external classifications and applying to them metrics from graph theory. © 2021 The Author(s). Financial support from the Helmholtz Association (HIRG-0069) is gratefully acknowledged. Ivan Savin acknowledges support from the Russian Science Foundation [RSF grant number 19-18-00262]. This work has benefited from presentations at workshops in Kiel, Strasbourg, Karlsruhe, the EMAEE conference in Brighton and the EAEPE conference in Bilbao. All remaining shortcomings are our responsibility.

The two-parameter Weibull probability distribution function is versatile for modelling wind speed frequency distribution and for estimating the energy delivery potential of wind energy systems if its shape and scale parameters, k and c, are correctly determined from wind records. In this study, different methods for determining Weibull k and c from wind speed measurements are reviewed and applied at four sample meteorological stations in Zimbabwe. The appropriateness of each method in modelling the wind data is appraised by its accuracy in predicting the power density using relative deviation and normalised root mean square error. From the methods considered, the graphical method proved to imitate the wind data most closely followed by the standard deviation method. The Rayleigh distribution (k=2 is also generated and compared with the wind speed data. The Weibull parameters were calculated by the graphical method for fourteen stations at which hourly wind speed data was available. These values were then used, with the assistance of appropriate boundary layer models, in the mapping of a wind power density map at 50m hub height for Zimbabwe. Keywords: Weibull distribution parameters, graphical method, power density.

Leaf area is important for estimating biomass productivity, adaptation to the environment, nutrition, and soil-water relations. It also plays an important role in determining the proper application rates of insecticides and fungicides. Image processing is considered one of the best methods for estimating the leaf area of a plant as it is inexpensive and saves time. In the image processing method, leaf area is calculated through pixel number statistics by counting the number of pixels in the leaf area region of digital images. In this study, a simple system based on image analysis using the ImageJ software application was developed to estimate cotton leaf area. Two hundred and forty Egyptian cotton (Giza 86) leaves were captured using a digital camera. These leaves were collected randomly from different heights and different fields at Kafer El-Dawar center, El-Behera Governorate, Egypt. The results obtained using the proposed method was then compared with those obtained using the graphical method. There were only minor differences between both sets of results. The proposed method is feasible and practicable for estimating cotton leaf area as it has only a small overall average absolute relative error of 3.46% compared to the graphical method. Further, the proposed method is rapid, simple, and inexpensive.

The authors gratefully thank the sponsorship of Fundação para a Ciência e Tecnologia through the Strategic Project UID/EMS/00667/2013 – UNIDEMI. Axiomatic Design classifies designs into three basic types: uncoupled, decoupled and coupled. The first type encompasses the ideal designs, where independence is always ensured, the second includes the designs where independence can be achieved using the right sequence to fine-tune the design parameters as to satisfy the given set of functional requirements, while the last comprises designs for which independence can never be achieved. Usually, coupled designs are avoided and designers are encouraged to redesign their solutions until an uncoupled or a decoupled one is achieved. Nevertheless, coupled solutions are often hard to avoid. This paper discusses this issue and uses a simple graphical example on how to adjust either the functional requirements or the design parameters of a 2-FR, 2-DP coupled design that is regarded as being uncoupled, as to attain the minimum information content. publishersversion published

In this study, five numerical Weibull distribution methods, namely, the maximum likelihood method, the modified maximum likelihood method (MLM), the energy pattern factor method (EPF), the graphical method (GM), and the empirical method (EM) were explored using hourly synoptic data collected from 1985 to 2013 in the district of Maroua in Cameroon. The performance analysis revealed that the MLM was the most accurate model followed by the EPF and the GM. Furthermore, the comparison between the wind speed standard deviation predicted by the proposed models and the measured data showed that the MLM has a smaller relative error of -3.33% on average compared to -11.67% on average for the EPF and -8.86% on average for the GM. As a result, the MLM was precisely recommended to estimate the scale and shape parameters for an accurate and efficient wind energy potential evaluation. Keywords : Empirical method; energy pattern factor method; graphical method; maximum likelihood method; modified maximum likelihood method; wind speed.

Geometric dimensioning and Tolerancing (GDT) constitutes the dominant approach for design and manufacture of mechanical parts that control inevitable dimensional and geometrical deviations within appropriate limits. The stack up of tolerances and their redistribution without hampering the functionality is very important for cost optimization. This paper presents a methodology that aims towards the systematic solution of tolerance stack up problem involving geometric characteristics.Conventional tolerance stack up analysis is usually difficult as it involves numerous rules and conditions. The methodology presented i.e. generic capsule method is straightforward and easy to use for stack up of geometrical tolerances of components and their assembly using graphical approach. In the work presented in this paper, angularity tolerance has been considered for illustration of the methodology. Two approaches viz. Worst Case (WC) and Root Sum Square (RSS) have been used. An example of dovetail mounting mechanism has been taken for purpose of stack up of angularity. Based on the stacked tolerance, it can be verified with the design tolerance of the assembly. Based on the comparison, designer has to reassign the appropriate tolerances to fulfil the functionality if required. If the stacked tolerance is as per designer requirement, then reallocation of tolerances on individual components should be done. Costs versus tolerance data are available for each component. With optimization technique, the optimized cost has been calculated for the assembly.

Geometric dimensioning and Tolerancing (GDT) constitutes the dominant approach for design and manufacture of mechanical parts that control inevitable dimensional and geometrical deviations within appropriate limits. The stack up of tolerances and their redistribution without hampering the functionality is very important for cost optimization. This paper presents a methodology that aims towards the systematic solution of tolerance stack up problem involving geometric characteristics.Conventional tolerance stack up analysis is usually difficult as it involves numerous rule and conditions. The methodology presented i.e. generic capsule method is straightforward and easy to use for stack up of geometrical tolerances of components and their assembly using graphical approach. In the work presented in this paper, angularity tolerance has been considered for illustration of the methodology. Two approaches viz. Worst Case (WC) and Root Sum Square (RSS) have been used. An example of dovetail mounting mechanism has been taken for purpose of stack up of angularity. This assembly consists of two parts i.e. dovetail male and dovetail female. Tolerance stack up has been done both for the components and their assembly. Need for computerisation of methodology for geometrical tolerance stack up of large assemblies has emerged out as the limitation of the proposed method.

Industrialized closing systems appear as rational solutions in steel-structured construction. These closing systems, consisting of multi-layered panels, have been applied in projects where it is intended to obtain a high sound transmission loss without raising the cost and without using a lot of mass. However, acoustic isolation depends on several factors, including the type of connection between the panels, requiring a preliminary study of the acoustic performance of the closing system to prevent future interventions. This paper uses a simplified graphical method to evaluate the influence of the type of connection (line-line, line-punctual or punctual-punctual) of industrialized closing panels on the estimation of the sound transmission loss that occurs across the wall constituted by these panels. The panels are combined, forming multi-layered closings interleaved by a layer of air, either without or with a sound-absorbing material between them. The results show that it is necessary to check the effectiveness of each type of fastening of the closing systems because, for example, for the frequency range between 500 and 2,000 Hz, the sound transmission loss of a closing system consisting of cementitious plate with glass wool and line-punctual and punctual-punctual connections exceeds in 6.25% the sound transmission loss of the same system with line-line fastening. For a system composed of expanded polystyrene with glass wool, the sound transmission loss provided by line-line fastening exceeds in 7.0% the sound transmission loss of the same closing system with line-punctual and punctual-punctual fastenings.

The paper presents a graphical method for estimating the excess pressure in penstocks under partial hydraulic hammer. Based on the proposed method, the maximum design load under hydraulic hammer in a high-pressure penstock of the Zaramagskaya HPP-1 was determined. Strength of metal shell and crescent rib of the penstock fork was evaluated under a specific load combination typical for hydraulic hammer. Variants of the fork structure reinforcement were considered. Comparison of strength reliability was performed for the variants of steel and composite steel-concrete construction of penstock fork.

One of the applied methods for environmental impact assessment is the index of global pollution (IGP) proposed by Rojanschi in 1991. This methodology enables the global estimation for the ecosystem state affected more or less by human activities. Unfortunately, Rojanschi’s method has a limitation; it can be applied only if at least three environmental components are considered. Frequently, many environmental impact assessment applications rely on analysis of only two environmental components. Therefore, this work aimed to develop a new graphical method to extend Rojanschi’s approach for the case of two environmental components. The proposed method avoids the average value of evaluation grades and uses only the graphical correspondence for calculation of the index of global pollution. A right-angle triangle graph methodology was proposed, where bases represented the values of evaluation grades. Thus, for the case of two environmental components, the index of global pollution was calculated as the relation between the ideal and real ecosystem states represented by the ratio between areas of external and enclosed right triangles. The developed graphical method was tested and validated for real case studies: the environmental impact assessment from a refinery located on the Romanian Black Sea Coast considering Air and Water environmental components and from a coal-fired thermoelectric power plant from Eastern Romania regarding Air and Soil environmental components. In this way, it was provided a reliable and faster tool to be used for the pollution characterization of human-derived chemicals for better decisions in risk management.