Excess air in the noble gas groundwater paleothermometer

Master of ScienceGeologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/115443/1/39015082859235.pd

On the Depth of Deep Neural Networks: A Theoretical View

People believe that depth plays an important role in success of deep neural networks (DNN). However, this belief lacks solid theoretical justifications as far as we know. We investigate role of depth from perspective of margin bound. In margin bound, expected error is upper bounded by empirical margin error plus Rademacher Average (RA) based capacity term. First, we derive an upper bound for RA of DNN, and show that it increases with increasing depth. This indicates negative impact of depth on test performance. Second, we show that deeper networks tend to have larger representation power (measured by Betti numbers based complexity) than shallower networks in multi-class setting, and thus can lead to smaller empirical margin error. This implies positive impact of depth. The combination of these two results shows that for DNN with restricted number of hidden units, increasing depth is not always good since there is a tradeoff between positive and negative impacts. These results inspire us to seek alternative ways to achieve positive impact of depth, e.g., imposing margin-based penalty terms to cross entropy loss so as to reduce empirical margin error without increasing depth. Our experiments show that in this way, we achieve significantly better test performance.Comment: AAAI 201

Bipolaronic blockade effect in quantum dots with negative charging energy

We investigate single-electron transport through quantum dots with negative charging energy induced by a polaronic energy shift. For weak dot-lead tunnel couplings, we demonstrate a bipolaronic blockade effect at low biases which suppresses the oscillating linear conductance, while the conductance resonances under large biases are enhanced. Novel conductance plateau develops when the coupling asymmetry is introduced, with its height and width tuned by the coupling strength and external magnetic field. It is further shown that the amplitude ratio of magnetic-split conductance peaks changes from 3 to 1for increasing coupling asymmetry. Though we demonstrate all these transport phenomena in the low-order single-electron tunneling regime, they are already strikingly different from the usual Coulomb blockade physics and are easy to observe experimentally.Comment: 6 pages, 5 figure

Learning Experiences of Asian International Undergraduate Students in U.S. Universities

The number of Asian international undergraduate students in U.S. universities is constantly increasing. This significant increase in number impacts universities in regards to its mission statements, administration system, academic atmosphere, and school environment (Andrade, 2008; Bertrand & Lee, 2012; Huang, 2006). The purpose of this literature review is to help administrators and educators in U.S. universities to effectively know the overall academic performance and college life of Asian international students by introducing their learning experiences through demonstrating data and examples from existed studies. Also, this research synthesis provides college administrators and educators with practical strategies to enhance the learning experiences of Asian international undergraduate students through analyses of successful case studies from various universities across the country. Selected research studies from relevant journals reveal that learning experiences of Asian international undergraduate students have a close relationship with the administration of universities and teaching strategies of educators (Constantine, Kindaichi, Okazaki, Gainor, Baden, 2005; Hung & Hyun, 2010)

THE ASSESSMENT INDICATORS OF TOURISM ECOSYSTEM HEALTH

The tourism ecosystem is the kind of special ecosystem in which destination residents, the external tourists and its surrounding environment are tightly interacted, and it is also the nature -economy-society complex that mainly carries out the tourism activity. As a multiplexed system, the tourism ecosystem also has the healthy problems. From the angle of forced system, this paper analyzes reasons of the system’s healthy problems and successfully builds tourism ecosystem health evaluating indicator system with the utilization pressure, the state, the response model. Besides, this paper carries on the synthetic evaluation and the analysis to the tourism ecosystem health's indicator system through bestowing on the weights, which proposes the new research mentality for the tourism sustainable development. Key words: tourism ecosystem, health, indicator system, evaluatio