Harmonization of Life Cycle Climate Performance and Its Improvements for Heat Pump Applications

Life Cycle Climate Performance (LCCP) is an evaluation method by which heating, ventilation, air conditioning and refrigeration systems can be evaluated for their global warming impact over the course of their complete life cycle. LCCP is more inclusive than previous metrics such as Total Equivalent Warming Impact. It is calculated as the sum of direct and indirect emissions generated over the lifetime of the system “from cradle to grave”. Direct emissions include all effects from the release of refrigerants into the atmosphere during the lifetime of the system. This includes annual leakage and losses during the disposal of the unit. The indirect emissions include emissions from the energy consumption during manufacturing process, lifetime operation, and disposal of the system. This thesis proposes a standardized approach to the use of LCCP and traceable data sources for all aspects of the calculation. An equation is proposed that unifies the efforts of previous researchers. Data sources are recommended for average values for all LCCP inputs. A residential heat pump sample problem is presented illustrating the methodology. The heat pump is evaluated at five U.S. locations in different climate zones. An excel tool was developed for residential heat pumps using the proposed method. The primary factor in the LCCP calculation is the energy consumption of the system. The effects of advanced vapor compression cycles are then investigated for heat pump applications. Advanced cycle options attempt to reduce the energy consumption in various ways. There are three categories of advanced cycle options: subcooling cycles, expansion loss recovery cycles and multi-stage cycles. The cycles selected for research are the suction line heat exchanger cycle, the expander cycle, the ejector cycle, and the vapor injection cycle. The cycles are modeled using Engineering Equation Solver and the results are applied to the LCCP methodology. The expander cycle, ejector cycle and vapor injection cycle are effective in reducing LCCP of a residential heat pump by 5.6%, 8.2% and 10.5%, respectively in Phoenix, AZ. The advanced cycles are evaluated with the use of low GWP refrigerants and are capable of reducing the LCCP of a residential heat by 13.7%, 16.3% and 18.6% using a refrigerant with a GWP of 10. To meet the U.S. Department of Energy’s goal of reducing residential energy use by 40% by 2025 with a proportional reduction in all other categories of residential energy consumption, a reduction in the energy consumption of a residential heat pump of 34.8% with a refrigerant GWP of 10 for Phoenix, AZ is necessary. A combination of advanced cycle, control options and low GWP refrigerants are necessary to meet this goal.

Self-Organizing Map Neural Architectures Based on Limit Cycle Attractors

Recent efforts to develop large-scale neural architectures have paid relatively little attention to the use of self-organizing maps (SOMs). Part of the reason is that most conventional SOMs use a static encoding representation: Each input is typically represented by the fixed activation of a single node in the map layer. This not only carries information in an inefficient and unreliable way that impedes building robust multi-SOM neural architectures, but it is also inconsistent with rhythmic oscillations in biological neural networks. Here I develop and study an alternative encoding scheme that instead uses limit cycle attractors of multi-focal activity patterns to represent input patterns/sequences. Such a fundamental change in representation raises several questions: Can this be done effectively and reliably? If so, will map formation still occur? What properties would limit cycle SOMs exhibit? Could multiple such SOMs interact effectively? Could robust architectures based on such SOMs be built for practical applications? The principal results of examining these questions are as follows. First, conditions are established for limit cycle attractors to emerge in a SOM through self-organization when encoding both static and temporal sequence inputs. It is found that under appropriate conditions a set of learned limit cycles are stable, unique, and preserve input relationships. In spite of the continually changing activity in a limit cycle SOM, map formation continues to occur reliably. Next, associations between limit cycles in different SOMs are learned. It is shown that limit cycles in one SOM can be successfully retrieved by another SOM’s limit cycle activity. Control timings can be set quite arbitrarily during both training and activation. Importantly, the learned associations generalize to new inputs that have never been seen during training. Finally, a complete neural architecture based on multiple limit cycle SOMs is presented for robotic arm control. This architecture combines open-loop and closed-loop methods to achieve high accuracy and fast movements through smooth trajectories. The architecture is robust in that disrupting or damaging the system in a variety of ways does not completely destroy the system. I conclude that limit cycle SOMs have great potentials for use in constructing robust neural architectures.

SCHUBERT’S WINTERREISE AND THE PIANO TRIO IN Eb; TWO REMARKABLE WORKS FROM ONE REMARKABLE YEAR – 1827: A RECORDING PROJECT

During Franz Schubert’s penultimate year of 1827, he produced two profoundly important and mature works that are the focus of this recording project. The works are, in chronological order: • Winterreise (cycle of 24 songs on the poetry of Wilhelm Müller, 1794-1827) • Piano Trio in Eb Major, Op. 100, D. 929 A unique feature of the project is to present Winterreise in two poetic orders: as traditionally performed and published by Schubert, and in the final ordering published by the poet. The program notes accompanying the dissertation’s three compact discs have extensive information as well as comparative tables of Müller’s and Schubert’s final ordering of the cycle. There are significant differences in ordering, and ultimately the listener will determine which is more dramatically satisfying. Dark melancholy is the central emotion in Winterreise, which Schubert composed at various times throughout 1827 in a mood of corresponding gloom and distress. By contrast, the summer and fall of that year produced, in quick succession, the two glowing and remarkable Piano Trios in Bb and Eb, the second of which is included on these compact discs. The contrast between the trios and Winterreise follows the outward circumstances of Schubert’s life and health, a pattern of sorrow and later consolation and elation. The sound recordings for this dissertation recording project are available on three compact discs that can be found in the Digital Repository at the University of Maryland (DRUM). Winterreise was recorded in August 2009, at the University of Baltimore recital hall in Baltimore, Maryland with University of Maryland Professor François Loup. The trio, recorded in live performance in Baltimore in the spring of 2010, features two members of the Baltimore Symphony Orchestra: Qing Li, B.S.O. principal second violin, and Bo Li, B.S.O. section cellist.

Online and Traditional Lectures: Evaluating Effects of Social Presence and Learner Control

Online courses are rapidly replacing traditional, face-to-face lectures in American universities (Allen & Seaman, 2011). As technology improves, this trend will likely continue and accelerate. Researchers must evaluate the impact of online courses compared to their traditional counterparts. This two-part study quantifies the effect of two variables – social presence and learner control – on students’ recall, application and perceived learning levels in different lecture formats. Students in introductory courses at a four-year, public, American university were randomly assigned into three groups to view distinct lecture formats, one in a traditional classroom and two via the Internet. Upon viewing the single lecture, the students were asked to fill out a test and survey to quantify teacher immediacy, recall and application, and perceived learning levels across lecture formats. The study found that different levels of social presence and learner control affected students’ perceived learning levels but did not impact recall or application.