Stiffness modeling of robotic manipulator with gravity compensator

The paper focuses on the stiffness modeling of robotic manipulators with gravity compensators. The main attention is paid to the development of the stiffness model of a spring-based compensator located between sequential links of a serial structure. The derived model allows us to describe the compensator as an equivalent non-linear virtual spring integrated in the corresponding actuated joint. The obtained results have been efficiently applied to the stiffness modeling of a heavy industrial robot of the Kuka family

Compliance error compensation in robotic-based milling

The paper deals with the problem of compliance errors compensation in robotic-based milling. Contrary to previous works that assume that the forces/torques generated by the manufacturing process are constant, the interaction between the milling tool and the workpiece is modeled in details. It takes into account the tool geometry, the number of teeth, the feed rate, the spindle rotation speed and the properties of the material to be processed. Due to high level of the disturbing forces/torques, the developed compensation technique is based on the non-linear stiffness model that allows us to modify the target trajectory taking into account nonlinearities and to avoid the chattering effect. Illustrative example is presented that deals with robotic-based milling of aluminum alloy

The study of metaphor as part of Critical Discourse Analysis

This article discusses how the study of metaphoric and more generally, figurative language use contributes to critical discourse analysis (CDA). It shows how cognitive linguists’ recognition of metaphor as a fundamental means of concept- and argument-building can add to CDA's account of meaning constitution in the social context. It then discusses discrepancies between the early model of conceptual metaphor theory and empirical data and argues that discursive-pragmatic factors as well as sociolinguistic variation have to be taken into account in order to make cognitive analyses more empirically and socially relevant. In conclusion, we sketch a modified cognitive approach informed by Relevance Theory within CDA

Activating metaphors:exploring the embodied nature of metaphorical mapping in political discourse

In this unit activity, I explore how students can make use of the principles of embodied cognition and meaning, and specifically the embodied nature of metaphor to explore political discourse and communication. Work in cognitive linguistics has highlighted the fact that humans construct a view of reality that is informed by our species-specific capacities and limitations, and our interaction with the social and physical world (Tyler, 2012). In these terms, language itself can be viewed as derived from conceptualizations that are based on physical and sensory images (Holme, 2012). Together these comprise a theory of embodied cognition that can be utilised in an educational context (Giovanelli 2014)

Load assessment and analysis of impacts in multibody systems

The evaluation of contact forces during an impact requires the use of continuous force-based methods. An accurate prediction of the impact force demands the identification of the contact parameters on a case-by-case basis. In this paper, the preimpact effective kinetic energy (Formula presented.) is put forward as an indicator of the intensity of the impact force along the contact normal direction. This represents a part of the total kinetic energy of the system that is associated with the subspace of constrained motion defined by the impact constraints at the moment of contact onset. Its value depends only on the mechanical parameters and the configuration of the system. We illustrate in this paper that this indicator can be used to characterize the impact force intensity. The suitability of this indicator is confirmed by numerical simulations and experimentsPostprint (author's final draft

European spaces and the Roma: Denaturalizing the naturalized in online reader comments

With the entry of several Eastern European nations into the European Union (EU), a “third” space has developed in the discourse for nations perceived as not fully integrated “inside” the EU system. This article investigates the construction of this “third space” in the resultant “moral panic” about undesired immigration from other EU countries and its potential drain on the social services of the United Kingdom and links it to Euroskeptic discourse in British media. The article uses construal operations from cognitive linguistics combined with critical discourse studies as a way of denaturalizing the discourse in online comments that focus on the Bulgarian/Romanian immigration issue which we then connect to anti-Roma discourse. Results reveal a view of the United Kingdom as contaminated by Roma and underscore the need for novel metaphors to be countered before they become entrenched and used as tools for political propaganda

Two analogy strategies: The cases of mind metaphors and introspection

Analogical reasoning is often employed in problem-solving and metaphor interpretation. This paper submits that, as a default, analogical reasoning addressing these different tasks employs different mapping strategies: In problem-solving, it employs analogy-maximising strategies (like structure mapping, Gentner & Markman 1997); in metaphor interpretation, analogy-minimising strategies (like ATT-Meta, Barnden 2015). The two strategies interact in analogical reasoning with conceptual metaphors. This interaction leads to predictable fallacies. The paper supports these hypotheses through case-studies on ‘mind’-metaphors from ordinary discourse, and abstract problem-solving in the philosophy of mind, respectively: It shows that (1) default metaphorical interpretations for vision- and space-cognition metaphors can be derived with a variant of the analogy-minimising ATT-Meta approach, (2) philosophically influential introspective conceptions of the mind can be derived with conceptual metaphors only through an analogy-maximising strategy, and (3) the interaction of these strategies leads to hitherto unrecognised fallacies in analogical reasoning with metaphors. This yields a debunking explanation of introspective conceptions

Weighing up Exercises on Phrasal Verbs: Retrieval Versus Trial-And-Error Practices

EFL textbooks and internet resources exhibit various formats and implementations of exercises on phrasal verbs. The experimental study reported here examines whether some of these might be more effective than others. EFL learners at a university in Japan were randomly assigned to four treatment groups. Two groups were presented first with phrasal verbs and their meaning before they were prompted to retrieve the particles from memory. The difference between these two retrieval groups was that one group studied and then retrieved items one at a time, while the other group studied and retrieved them in sets. The two other groups received the exercises as trial-and-error events, where participants were prompted to guess the particles and were subsequently provided with the correct response. One group was given immediate feedback on each item, while the other group tackled sets of 14 items before receiving feedback. The effectiveness of these exercise implementations was compared through an immediate and a 1-week delayed post-test. The best test scores were obtained when the exercises had served the purpose of retrieval, although this advantage shrank in the delayed test (where scores were poor regardless of treatment condition). On average 70% of the post-test errors produced by the learners who had tackled the exercises by trial-and-error were duplicates of incorrect responses they had supplied at the exercise stage, which indicates that corrective feedback was often ineffective

'Riots engulfed the city':an experimental study investigating the legitimating effects of fire metaphors in discourses of disorder

In Cognitive Linguistic Critical Discourse Studies (CL-CDS), metaphor is identified as a key index of ideology and an important device in the legitimation of social action. From this perspective, metaphor is a cognitive-semiotic operation, invoked by metaphorical expressions in discourse, in which a source frame is mobilised to provide a template for sense-making inside a target frame, leading to particular framing effects. However, the extent to which metaphors in discourse genuinely activate an alternative frame and thereby achieve framing effects has recently been subject to question. Amid calls for more empirical forms of analysis in Critical Discourse Studies, the paper reports two experiments testing the legitimating framing effects of fire metaphors in discourses of disorder. Results show that images of fire and fire metaphors in the absence of competing images facilitate support for police use of water cannon in response to social unrest. The study not only justifies attention to metaphor in CL-CDS but similar effects across semiotic modalities are interpreted as evidence in support of simulation-based theories of metaphor

Metaphor in organizational research: Context, modalities and implications for research introduction

We provide a general overview of previous work which has explored the use of metaphors in organizational research. Differences in focus and form of research on metaphors are noted. Work in organization theory (OT) and organizational communication (OC) generally features prescriptive metaphors that aid the practice of theorizing and research; research in organizational development (OD) tends to use metaphors for intervention in individual and group decision-making; while studies of organizational behaviour (OB) emphasize the metaphors-in-use within individuals' sensemaking accounts of critical events within their organization. Alongside these differences in focus, the form of metaphor analysis also differs across these contexts, ranging from text- and discourse-based analysis to the analysis of non-linguistic modalities such as pictorial signs, gestures and artefacts. Based on our overview of previous work, we call for greater attention to methodological issues around metaphor identification and analysis and outline a number of directions for further research