On the inside writing out : the dramatic represention of the private boys' boarding school on the South African stage.

Thesis (M.A.)-University of Natal, Durban, 2001.This dissertation sets out to analyze the manner in which the writers of dramatic fiction deconstruct the mythology and ideology of the private boys' boarding school in their work. It also seeks to interrogate the sociological and philosophical notions that underpin this fictional work. The central thrust of this dissertation is to explore the representation of the private boys' boarding school experience on the South African stage, with particular reference to writers whose work reflects their personal experiences within such institutions. Private boys' boarding schools promote the ideology that they provide a superior education based on liberal and democratic principles. These institutions supposedly oversee the development of the individual's mental, physical, spiritual, cultural and social education. The projected ideology of the private boys' boarding schools has become entrenched and has manifested itself as a pervasive mythology, which glorifies and glamourises the social reality of such institutions. This mythology is challenged and refuted by the appropriation of various sociological, and philosophical theorists, including: traditional Marxist critiques such as the theories of Samuel Bowles and Herbert Gintis (1976); structuralist theories such as those proposed by Louis Althusser (1971) and Antonio Gramsci (1971), whose notions of hegemony carry much relevance when considering private boys' boarding schools; and finally, Michel Foucault's (1977) theories of power and power hierarchies (Lotringer, 1989; Smart, 1985). Since South Africa's democratization in 1994, a number of fictional works have emerged that have engaged with the social reality of private boys' boarding schools. Most notably, two plays, Anthony Akerman's Old Boys (2000) and John van de Ruit's War Cry (1999), have highlighted issues surrounding private boys' boarding schools in South Africa. Together with a variety of texts written for different media these works have formed a critical base that, to some degree, has undermined the supremely positive resonance of the entrenched private school mythology, and in so doing, challenge the projected ideology. This dissertation's prime focus is on South African private boys' boarding schools; however, it also includes texts that articulate the social reality of private education in England and America. These texts are relevant firstly because the South African private schools are modeled very closely on the English public school system and secondly, because their inclusion adds weight and variety to the discussion. Important areas of study within this dissertation will be the interpretation of the various thematic concerns raised, and character constructions created by the various writers. This will be underpinned by the theoretical framework, which analyzes systems of power and power hierarchies, and the notion of hegemonic masculinity. Finally, the private boys' boarding school will be examined as a site for hegemonic struggle where power and privilege are continually contested in a relationship characterized by coercion and consent. The critical discourse of the fictional texts and its theoretical underpinning will be placed in opposition to the elitist mythology of the private boys' boarding school and the ideology that these institutions espouse

Adaptation rate in joint dynamics depends on the time-varying properties of the environment

During movement, our central nervous system (CNS) takes into account the dynamics of our environment to optimally adapt our joint dynamics. In this study we explored the adaptation of shoulder joint dynamics when a participant interacted with a time-varying virtual environment created by a haptic manipulator. Participants performed a position task, i.e., minimizing position deviations, in face of continuous mechanical force perturbations. During a trial the environmental damping, mimicked by the manipulator, was either increased (0 to 200 N s/m) or decreased (200 to 0 N s/m) in 1 s or 8 s. A system identification technique, kernel-based regression, was used to reveal time-varying shoulder joint dynamics using the frequency response function (FRF). The FRFs revealed that the rate at which shoulder joint dynamics is adapted depends on the rate and direction of change in environmental damping. Adaptation is slow, but starts immediately, after the environmental damping increases, whereas adaptation is fast but delayed when environmental damping decreases. The results obtained in our participants comply with the framework of optimal feedback control, i.e., adaptation of joint dynamics only takes place when motor performance is at risk or when this is energetically advantageous.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Biomechatronics & Human-Machine Contro

Quantitative comparison of time-varying system identification methods to describe human joint impedance

Accurate and swift tuning of joint impedance is crucial to perform movement and interaction with our environment. Time-varying system identification enables quantification of joint impedance during movement. Many methods have been developed over the years, each with their own mathematical approach and underlying assumptions. Yet, for the identification of joint impedance, a systematic comparison revealing each method's unique strengths and weaknesses, is lacking. Here, we propose a quantitative framework to compare these methods. The framework is used to review five time-varying system identification methods using both simulated data and experimental data. These methods included three time-domain methods: ensemble, short data segment, and basis impulse response function; and two frequency-domain methods: ensemble spectral, and kernel-based regression. In the simulation study, joint stiffness – the static component of impedance – was simulated as a square wave to mimic the most extreme case of time-varying behavior. The identification results were compared based on the (1) variance accounted for (VAF), (2) bias, (3) random, and (4) total estimation error with respect to the simulated joint stiffness; and (5) rise time between two stiffness levels. In the experimental study, human ankle joint impedance was identified. Identification performance was compared using the variability in estimating joint stiffness – representative of the random error – and VAF. The performance metrics revealed distinct identification properties for each method. Therefore, researchers must make a well-justified decision which method is most appropriate for their application. The combination of simulation and experimental work with extensive performance quantification creates a framework for quantitative assessment of newly developed time-varying system identification methods.Biomechatronics & Human-Machine Contro

Revealing time-varying joint impedance with kernel-based regression and nonparametric decomposition

During movements, humans continuously regulate their joint impedance to minimize control effort and optimize performance. Joint impedance describes the relationship between a joint's position and torque acting around the joint. Joint impedance varies with joint angle and muscle activation and differs from trial-to-trial due to inherent variability in the human control system. In this paper, a dedicated time-varying system identification (SI) framework is developed involving a parametric, kernel-based regression, and nonparametric, “skirt decomposition,” SI method to monitor the time-varying joint impedance during a force task. Identification was performed on single trials and the estimators included little a priori assumptions regarding the underlying time-varying joint mechanics. During the experiments, six (human) participants used flexion of the wrist to apply a slow sinusoidal torque to the handle of a robotic manipulator, while receiving small position perturbations. Both methods revealed that the sinusoidal change in joint torque by activation of the wrist flexor muscles resulted in a sinusoidal time-varying joint stiffness and resonance frequency. A third-order differential equation allowed the parametric kernel-based estimator to explain on average 76% of the variance (range 52%-90%). The nonparametric skirt decomposition method could explain on average 84% of the variance (range 66%-91%). This paper presents a novel framework for identification of time-varying joint impedance by making use of linear time-varying models based on a single trial of data.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Biomechatronics & Human-Machine ControlTeam Jan-Willem van Wingerde