The Death of the Performer: Thoughts Towards a Barthesian Theory of Contemporary Music

When examining a particular creative work, one has to be aware of a number of hidden relationships embedded within that work as a whole. Who created this work? What was their goal in doing so (if there ever was an established goal)? How am I supposed to interpret this work, given the nature in which it was created? Going down these paths of inquiry can serve to make the relationship between the audience and the work itself murkier, turning the simple act of consumption into something much more sinister and perilous. But it is necessary that we [the global we] head down such paths, if for no other reason that the artistic climate of the last several decades has in many ways become dependent on such introspective lines of inquiry. This can be seen clearly in several avenues of philosophical thought, and it is the goal of this paper to explore one particular example of such contemplative navel-gazing: Roland Barthes. To start, I will offer my own take on the central concepts of Barthes' article, with a secondary goal of reconciling his ideology with current trends in contemporary Western art music. In the end, I plan to establish a connection between recent and on-going trends in the contemporary music world and the reader-centric philosophy of Barthes

Energy Harvesting toward the Vibration Reduction of Turbomachinery Blades via Resonance Frequency Detuning

Piezoelectric-based energy harvesting devices provide an attractive approach to powering remote devices as ambient mechanical energy from vibrations is converted to electrical energy. These devices have numerous potential applications, including actuation, sensing, structural health monitoring, and vibration control -- the latter of which is of particular interest here. This work seeks to develop an understanding of energy harvesting behavior within the framework of a semi-active technique for reducing turbomachinery blade vibrations, namely resonance frequency detuning. In contrast with the bulk of energy harvesting research, this effort is not focused on maximizing the power output of the system, but rather providing the low power levels required by resonance frequency detuning. The demands of this technique dictate that harvesting conditions will be far from optimal, requiring that many common assumptions in conventional energy harvesting research be relaxed. Resonance frequency detuning has been proposed as a result of recent advances in turbomachinery blade design that have, while improving their overall efficiency, led to significantly reduced damping and thus large vibratory stresses. This technique uses piezoelectric materials to control the stiffness, and thus resonance frequency, of a blade as the excitation frequency sweeps through resonance. By detuning a structure*s resonance frequency from that of the excitation, the overall peak response can be reduced, delaying high cycle fatigue and extending the lifetime of a blade. Additional benefits include reduced weight, drag, and noise levels as reduced vibratory stresses allow for increasingly light blade construction. As resonance frequency detuning is most effective when the stiffness states are well separated, it is necessary to harvested at nominally open- and short-circuit states, corresponding to the largest separation in stiffness states. This presents a problem from a harvesting standpoint however, as open- and short-circuit correspond to zero charge displacement and zero voltage, respectively, and thus there is no energy flow. It is, then, desirable to operate as near these conditions as possible while still harvesting sufficient energy to provide the power for state-switching. In this research a metric is developed to study the relationship between harvested power and structural stiffness, and a key result is that appreciable energy can be harvested far from the usual optimal conditions in a typical energy harvesting approach. Indeed, sufficient energy is available to power the on-blade control while essentially maintaining the desired stiffness states for detuning. Furthermore, it is shown that the optimal switch in the control law for resonance frequency detuning may be triggered by a threshold harvested power, requiring minimal on-blade processing. This is an attractive idea for implementing a vibration control system on-blade, as size limitations encourage removing the need for additional sensing and signal processing hardware