Search results

The purpose of this paper is to propose a deformable two-wheel-like mobile mechanism based on overconstrained mechanism, with the abilities of fast rolling and obstacle surmounting. The drive torque of the multi-mode motions is generated by self-deformation. Moreover, the analyses of feasibility and locomotivity of two mobile modes are presented.

The main body of the two-wheel-like mobile mechanism is a kind of centrally driven 4 R linkages. The mobile mechanism can achieve the capabilities of fast rolling and obstacle surmounting through integrating two mobile modes (spherical-like rolling mode and polyhedral-like obstacle-surmounting mode) and can switch to the corresponding mode to move or surmount obstacles. The mobility and kinematics of the mobile modes are analyzed.

Based on the results of kinematics analysis and dynamics analysis of the wheel-like mechanism, the spherical-like rolling mode has the capability of fast rolling, and the polyhedral-like obstacle-surmounting mode has the capability of surmounting different obstacle heights by two submodes (quasi-static obstacle-surmounting submode and dynamic obstacle-surmounting submode). The proposed concept is verified by experiments on a physical prototype.

The work presented in this paper is a novel exploration to apply bar linkages in the field of scout. The two-wheel-like mobile mechanism improves the torque imbalance of bar linkages by centrally driven method, removes the rear support structures of the traditional two-wheeled mechanisms by self-deformation and increases the height of obstacle surmounting by mode switching angle.

With the aim of shedding new light on the characteristics of human capital in its relationship with organizational innovation, this paper develops a novel theoretical and empirical exploration of the characteristics of human capital, both executives' experience and employees' average education level, as well as the moderating effect of female ownership, on two different aspects of organizational innovation.

Data were obtained from the World Bank's China private manufacturing enterprise questionnaire survey. The study employs regression analysis of a logistic model using 1,598 samples, because the dependent variable of an organization's innovation index is a binary variable.

Using World Bank survey data of Chinese private manufacturing enterprises, the authors find that executives' experience has a significantly positive effect on process innovation. Female ownership strengthens the relationship between executives' experience and process innovation. Moreover, the results indicate that employees' average educational level has a significantly positive effect on product innovation. Female ownership strengthens the relationships between employees' average educational level and organizational innovation including product innovation and process innovation. This study highlights the importance of simultaneously testing the effects of human capital and gender heterogeneity on organizational innovation activities.

This study explores the impact of human capital on organizational innovation activities in the context of the Chinese manufacturing industry. Moreover, organizational innovation activities are divided into two aspects: product innovation and process innovation. This study separately discusses the effect of human capital on these two kinds of innovation in detail. Finally, female ownership is selected as a moderating variable, and it is demonstrated that interactions of female owners with executives' experience and employees' average educational level have a positive impact on increasing different kinds of organizational innovation. The authors identify new boundary conditions for the domain of female research that are sorely lacking in the present literature.

The purpose of this paper is to investigate the tribological properties of the WC/TiC-Co substrate under different loading conditions under three impact abrasive wear conditions.

The three body collisional wear behavior of Co alloy with WC and TiC at three impact energy was studied from 1 to 3 J. Meanwhile, the microstructure, hardness, phase transformation and wear behavior of these specimens were investigated by scanning electron microscopy, Rockwell hardness (HRV), EDS and impact wear tester. The resulting wear rate was quantified by electronic balance measurements under different pressures.

The specific wear rate increases with the increase of the nonlinearity of the impact energy and the increase in the content of WC or TiC. The effect of TiC on wear rate is greater than that of WC, but the hardness is smaller. The wear characteristics of the samples are mainly characterized by three kinds of behavior, such as cutting wear, abrasive wear and strain fatigue wear. The WC-Co with fewer TiC samples suffered heavier abrasive wear than the more TiC samples under both low and high impact energy and underwent fewer strain fatigue wears under high impact energy.

The experimental results show that the wear resistance of the Co alloy is improved effectively and the excellent impact wear performance is achieved. The results can be used in cutting tools such as coal mine cutting machines or other fields.

The purpose of this study to shed light on the importance of social media hosted content related to socially-motivated discussions. Moving from the field of communication for development, the research leverages social media as a powerful tool for collecting and analyse peer-to-peer communication towards the conceptualization of eVoices of Unheard. The deep understanding of these conversation can generate recommendations for organizations and governments designing and providing interventions fostering local socio-economic development.

The study presents a large-scale analysis of social media interactions on the topic “#favela” to generate insights into a social network structure, narrative contents and meaning generated.

Structurally, the analysed networks are comparable with those presented in current academic literature; automatic text analysis confirmed the promise of the inner value of communication for development opening the floor to conceptualization of the “eVoices of unheard”, which is the collective and conscious use of social media to mediate community discussions about tangible and intangible issues related to socio-economic development.

Framed within the rise of interactive communication for development this research show that social media an support the notion of voice proposed by Couldry (2010) moving from process (i.e. the recording of the voice) towards value (i.e. the possibility of giving an account of one’s life and its conditions to have an impact on human life and resources) thereby understanding intangible issues related with socio-economic development.

This study explored how Brazilian young adults who cook interact with cooking-related content on social media and how such content fits their cooking routine.

Semi-structured interviews (n = 31) were transcribed, inductively and reflexively thematic analysed.

Interactions happened both in recreational and intentional ways, which coexisted and alternated depending on participants' motives and schedules. Recreational interactions such as browsing and saving happened more for self-entertainment and to some participants, to help meal planning and food shopping. Intentional interactions such as searching and sharing happened to fulfil specific needs which arised on cooking occasions, leading to agency development. Young adults who self-identified as being less experienced in cooking reported checking and comparing many recipes, as well as relying on video features to improve skills and develop self-efficacy. Despite showing agency in cooking-related matters, participants perceived lack of time to cook as an important barrier to cooking more. Intentional interactions with cooking content were linked to more established cooking routines, indicating the importance of social media to young adults' development of self-efficacy and improvement of skills.

The use of social media to search for cooking-related content is recommended by Brazilian dietary guidelines to develop cooking and food skills, but research on if and how the interaction occurs, and the resulting knowledge is put into practice, is scarce. This study addressed this gap and proposed practical implications to inform the development of interventions employing social media to improve young adults' cooking skills and health.

Analytical determination of harmonic components of current in electric circuits containing semiconductor converters with the use of a small parameter method (SPM) in frequency domain. The paper aims to discuss these issues.

A SPM realized in frequency domain was used in the analytical analysis of electric circuits with semiconductor converters. An automated method of formation of orthogonal harmonic components of electrical values on the basis of discrete convolution algorithm was used to provide the possibility of realization of calculation in frequency domain. A nonlinear characteristic of a semiconductor converter was presented by the method of numerical approximation. A numerical structured simulation method was applied to determination of the reference values of current in the analyzed circuit. Laws of theoretical electrical engineering were used for formation of the equations of voltage balance in the circuit with a nonlinear element.

It is shown that application of a SPM with its realization in frequency domain enables significant simplification of the process of the analysis of electric circuits with semiconductor converters in an analytical form and facilitation of calculation automation. Analytical and numerical calculation of a circuit with a diode under active-inductive load demonstrated efficiency and sufficient accuracy of the proposed method. It is shown that increase of the order of approximating polynomial and of the number of the analyzed harmonics provides the improvement of the accuracy of numerical calculations.

The results of the work can be used in calculation of electrotechnical devices containing semiconductor appliances and electric devices with nonlinear characteristics. Moreover, the obtained results enable studying the processes of compensation of current higher harmonics in electric networks with a nonlinear load containing semiconductor converters.

For the first time it was proposed to apply a SPM with its realization in frequency domain to the analysis of nonlinear electric circuits. The significance of the paper consists in the fact that the offered method makes it possible to carry out both circuit analytical and numerical analysis with the possibility of its automation.