Exponential Decay and Fermi's Golden Rule from an Uncontrolled Quantum Zeno Effect

We modify the theory of the Quantum Zeno Effect to make it consistent with the postulates of quantum mechanics. This modification allows one, throughout a sequence of observations of an excited system, to address the nature of the observable and thereby to distinguish survival from non-decay, which is necessary whenever excited states are degenerate. As a consequence, one can determine which types of measurements can possibly inhibit the exponential decay of the system. We find that continuous monitoring taken as the limit of a sequence of ideal measurements will only inhibit decay in special cases, such as in well-controlled experiments. Uncontrolled monitoring of an unstable system, however, can cause exponentially decreasing non-decay probability at all times. Furthermore, calculating the decay rate for a general sequence of observations leads to a straightforward derivation of Fermi's Golden Rule, that avoids many of the conceptual difficulties normally encountered. When multiple decay channels are available, the derivation reveals how the total decay rate naturally partitions into a sum of the decay rates for the various channels, in agreement with observations. Continuous and unavoidable monitoring of an excited system by an uncontrolled environment may therefore be a mechanism by which to explain the exponential decay law.Comment: 18 pages, no figures. Added references to theory and experiments, distinguished survival from non-decay, and added derivation for multiple decay channel

Dilemma elimination for achieving compliance

Drama theory provides a means of modelling pre-play communication: that is the exchanges which take place between parties as they collectively shape the confrontational arena within which they must eventually take decisive action. Participants communicate objects called ‘positions’ and ‘intentions’ and share their ‘doubts’ about each others’ declarations. On the basis of this ‘communicated common knowledge’ those involved, seeking to act rationally, normally experience dilemmas. These prompt them to devise frame-breaking changes that alter the form of the interaction, perhaps placing additional pressure upon some parties whilst relieving that experienced by others. At some point these changes cease and the participants play their actions, possibly using game theory to inform their individual strategies. Within this context, this paper explores the process of dilemma elimination, specifically seeing whether there may be favourable sequences that could be adopted: these would show a commander the most beneficial route for advantageously resolving confrontations with other parties. Such sequences would both reduce or eliminate the commander’s own dilemmas, whilst aggravating or otherwise engineering those facing other parties so as to render them more compliant. The paper uses a new version of drama theory (DT2) that offers a simpler but no less powerful formulation of the dilemmas which has as yet not been widely applied in any field

Digital controller for a Baum folding machine

A digital controller for controlling the operation of a folding machine enables automatic folding of a desired number of sheets responsive to entry of that number into a selector. The controller includes three decade counter stages for corresponding rows of units, tens and hundreds push buttons. Each stage including a decimal-to-BCD encoder, a buffer register, and a digital or binary counter. The BCD representation of the selected count for each digit is loaded into the respective decade down counters. Pulses generated by a sensor and associated circuitry are used to decrease the count in the decade counters. When the content of the decade counter reaches either 0 or 1, a solenoid control valve is actuated which interrupts operation of the machine. A repeat switch, when actuated, prevents clearing of the buffer registers so that multiple groups of the same number of sheets can be folded without reentering the number into the selector

Flight test validation of a design procedure for digital autopilots

Commercially available general aviation autopilots are currently in transition from an analogue circuit system to a computer implemented digital flight control system. Well known advantages of the digital autopilot include enhanced modes, self-test capacity, fault detection, and greater computational capacity. A digital autopilot's computational capacity can be used to full advantage by increasing the sophistication of the digital autopilot's chief function, stability and control. NASA's Langley Research Center has been pursuing the development of direct digital design tools for aircraft stabilization systems for several years. This effort has most recently been directed towards the development and realization of multi-mode digital autopilots for GA aircraft, conducted under a SPIFR-related program called the General Aviation Terminal Operations Research (GATOR) Program. This presentation focuses on the implementation and testing of a candidate multi-mode autopilot designed using these newly developed tools

Asymmetric Time Evolution And Indistinguishable Events

With a time asymmetric theory, in which quantum mechanical time evolution is given by a semigroup of operators rather than by a group, the states of open systems are represented by density operators exhibiting a branching behavior. To treat the indistinguishably of the members of experimental ensembles, we hypothesize that environmental interference occurs during events that are themselves fundamentally indistinguishable.Center for Complex Quantum System

Advanced symbology for general aviation approach to landing displays

A set of flight tests designed to evaluate the relative utility of candidate displays with advanced symbology for general aviation terminal area instrument flight rules operations are discussed. The symbology was previously evaluated as part of the NASA Langley Research Center's Terminal Configured Vehicle Program for use in commercial airlines. The advanced symbology included vehicle track angle, flight path angle and a perspective representation of the runway. These symbols were selectively drawn on a cathode ray tube (CRT) display along with the roll attitude, pitch attitude, localizer deviation and glideslope deviation. In addition to the CRT display, the instrument panel contained standard turn and bank, altimeter, rate of climb, airspeed, heading, and engine instruments. The symbology was evaluated using tracking performance and pilot subjective ratings for an instrument landing system capture and tracking task

Sustaining a focus on occupation in community mental health practice

Occupational therapists working in community mental health teams (CMHTs) are often challenged to justify their unique approach to health through occupation, within an environment that tends to press for generic working. Such a challenge requires practitioners to identify and communicate evidence that supports their unique occupational contribution. In the absence of extensive robust and relevant research evidence, it is suggested that the contribution of theoretical evidence be considered. This paper, therefore, explores the potential of occupational justice and its related concepts to provide the profession with a theoretical justification for occupational therapists adopting an occupation-focused role in CMHTs. It begins with an overview of how CMHTs, generic working and occupational science have evolved. The concept of occupational justice and its related risk factors are then analysed in relation to practice. The potential conflict between the professional commitment to client-centred practice and the generic worker model is also discussed. The paper concludes with recommendations for further exploration and consideration