Probabilistically safe vehicle control in a hostile environment

In this paper we present an approach to control a vehicle in a hostile environment with static obstacles and moving adversaries. The vehicle is required to satisfy a mission objective expressed as a temporal logic specification over a set of properties satisfied at regions of a partitioned environment. We model the movements of adversaries in between regions of the environment as Poisson processes. Furthermore, we assume that the time it takes for the vehicle to traverse in between two facets of each region is exponentially distributed, and we obtain the rate of this exponential distribution from a simulator of the environment. We capture the motion of the vehicle and the vehicle updates of adversaries distributions as a Markov Decision Process. Using tools in Probabilistic Computational Tree Logic, we find a control strategy for the vehicle that maximizes the probability of accomplishing the mission objective. We demonstrate our approach with illustrative case studies

Small UAV Research and Evolution in Long Endurance Electric Powered Vehicles

This paper describes recent research into the advancement of small, electric powered unmanned aerial vehicle (UAV) capabilities. Specifically, topics include the improvements made in battery technology, design methodologies, avionics architectures and algorithms, materials and structural concepts, propulsion system performance prediction, and others. The results of prototype vehicle designs and flight tests are discussed in the context of their usefulness in defining and validating progress in the various technology areas. Further areas of research need are also identified. These include the need for more robust operating regimes (wind, gust, etc.), and continued improvement in payload fraction vs. endurance

Nanoscale surface element identification and dopant homogeneity in the high-TcT_{c} superconductor PrxCa1−xFe2As2Pr_xCa_{1−x}Fe_2As_2

We use scanning tunneling microscopy to determine the surface structure and dopant distribution in $Pr_xCa_{1−x}Fe_2As_2$, the highest-Tc member of the 122 family of iron-based superconductors. We identify the cleaved surface termination by mapping the local tunneling barrier height, related to the work function. We image the individual Pr dopants responsible for superconductivity, and show that they do not cluster, but in fact repel each other at short length scales. We therefore suggest that the low volume fraction high-Tc superconducting phase is unlikely to originate from Pr inhomogeneity.Physic

Close-coupling calculations of rotational energy transfer in p-H2+HD

We report quantum-mechanical close-coupling calculations for rotational state resolved cross sections for p-H2+HD collisions. The low temperature limit of p-H2+HD is investigated, which is of significant astrophysical interest in regard to the cooling of primordial gas and the interstellar media. Sharp resonances have been reproduced in the cross sections of some transition states at very low kinetic energies, E< 0.00001 eV.Comment: 10 pages, 6 figure

The use of corporate reputation in the development of brand image strategy in the Taiwanese pharmaceutical industry

This doctoral research aims to investigate the reputation building process of companies and to examine the applicability of western-developed theories about the uses of corporate reputation in a non-western context. It is the first study that synthesises three theories (value creation, strategic resources and corporate communication) to examine the strategic consequences of the uses of corporate reputation. Corporate reputation is an attribute or a set of attributes ascribed to a firm and inferred from the firm’s past actions. It is the belief of market participants about a firm’s strategic character (Weigelt and Camerer, 1988). Also, corporate reputation is the public’s cumulative judgement of a firm over time (Roberts and Dowling, 2002). The review of theoretical literature indicates the uses of corporate reputation by business organizations can be theorized along six dominant paradigmatic perspectives: 1-public relations; 2-marketing; 3-management, 4-economic; 5-sociological; 6-finance and accounting. The uses of corporate reputation in these six paradigms are comprehensively discussed. The objective of this study is to establish the use of corporate reputation in the development of brand image strategy. A review of the uses of the concept of corporate reputation is discussed in detail in chapter 2. The review of the literature also identified a research gap by showing that scarce research has been conducted on how these three main functions (value creation, strategic resources and corporate communication) affect a company’s brand positioning strategy. The following research question thus is proposed: How do (Taiwanese pharmaceutical) companies use their corporate reputation to develop a brand image strategy? The research hypotheses based on three theories (value-based theory, resource-based theory and integrated marketing communication theory) appear in Chapter 3. The research question is constructed theoretically, and then a conceptual model, which begins with three antecedents of corporate reputation and simultaneously illustrates the outcomes of their use, are discussed. The construct of the uses of corporate reputation has three dimensions: value creation, strategic resources and corporate communication. Each of these three dimensions includes several items. The items were proposed based on the previous researchers’ summaries and the qualitative interview. The researcher will then depict the proposed research conceptual framework and a number of hypotheses that will be further investigated and tested. Then the quantative study was completed by providing the data analysis and the results were explained. A multi-stage procedure was involved in this research. First, data examination and screening to prepare for subsequent quantitative analyses and then the descriptive statistics were presented. Second, a reliability test was performed on measurement scales to ensure that they achieve an acceptable level of reliability for further analysis. The resulting solutions were then re-assessed using confirmatory factor analysis. Finally, PLS (Partial Least Squares) was used to test the hypothesized relationships between the research constructs as postulated in the conceptual model, and to assess the overall goodness-of-fit between the proposed model and the collected data set. The researcher then discusses the validation of the measurement model and the research findings. The findings are then further discussed in terms of the contribution to marketing theory and relevance to marketing managers. Then the items of adapted scales were subjected to several rounds of adjustments and were finally found to possess acceptable measurement properties. Reliability and construct validity tests indicated that all scales satisfied widely accepted criteria such as the minimum reliability of 0.7. The results of scale purification will be discussed. And an evaluation of the research hypotheses and their significance are summarized, the findings of all hypotheses testing will be reviewed and compared with previous research. According to the research findings, the hypotheses that value creation, as one dimension of corporate reputation, has a positive impact on brand segmentation, brand differentiation and brand positioning are all accepted. The hypotheses that strategic resource, as one dimension of corporate reputation, has a positive impact on brand segmentation and brand differentiation are rejected. However, the hypothesis that strategic resource, as one dimension of corporate reputation, has a positive impact on brand positioning is accepted. The hypotheses that corporate communication, as one dimension of corporate reputation, has a positive impact on brand segmentation and brand differentiation are both accepted. The hypothesis that corporate communication, as one dimension of corporate reputation, has a positive impact on brand positioning is partially supported. Finally, the hypothesis that the (see in Table 5.18) moderating effect of price policy on corporate reputation has a positive impact on brand image strategy is partially but negatively supported. This thesis makes a significant contribution to the study of corporate reputation of firms in the Taiwanese pharmaceutical industry from the robustness of the qualitative and quantitative data collection.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

State resolved rotational excitation cross sections and rates in H2+H2 collisions

Rotational transitions in molecular hydrogen collisions are computed. The two most recently developed potential energy surfaces for the H2-H2 system are used from the following works: 1) A.I. Boothroyd, P.G. Martin, W.J. Keogh, M.J. Peterson, J. Chem. Phys., 116 (2002) 666, and 2) P. Diep, J.K. Johnson, J. Chem. Phys., 113 (2000) 3480; ibid. 112, 4465. Cross sections for rotational transitions 00->20, 22, 40, 42, 44 and corresponding rate coefficients are calculated using a quantum-mechanical approach. Results are compared for a wide range of kinetic temperatures 300 K < T < 3000 K.Comment: 9 pages, 3 figures, 3 table

Menthol stereoisomers exhibit different effects on α4β2 nAChR upregulation and dopamine neuron spontaneous firing

Menthol contributes to poor cessation rates among smokers, in part because menthol enhances nicotine reward and reinforcement. Mentholated tobacco products contain (−)-menthol and (+)-menthol, in varying proportions. We examined these two menthol stereoisomers for their ability to upregulate α4β2 nAChRs and to alter dopamine neuron firing frequency using long-term, low-dose (≤ 500 nM) exposure that is pharmacologically relevant to smoking. We found that (−)-menthol upregulates α4β2 nAChRs while (+)-menthol does not. We also found that (−)-menthol decreases dopamine neuron baseline firing and dopamine neuron excitability, while (+)-menthol exhibits no effect. We then examined both stereoisomers for their ability to inhibit α4β2 nAChR function at higher concentrations (>10 µM) using the Xenopus oocyte expression system. To probe for the potential binding site of menthol, we conducted flooding simulations and site-directed mutagenesis. We found that menthol likely binds to the 9’ position on the TM2 helix. We found that menthol inhibition is dependent on the end-to-end distance of the side chain at the 9’ residue. Additionally, we have found that (−)-menthol is only modestly (∼25%) more potent than (+)-menthol at inhibiting wildtype α4β2 nAChRs and a series of L9’ mutant nAChRs. These data reveal that menthol exhibits a stereoselective effect on nAChRs and that the stereochemical effect is much greater for long-term, sub µM exposure in mice than for acute, higher level exposure. We hypothesize that of the two menthol stereoisomers, only (−)-menthol plays a role in enhancing nicotine reward through nAChRs on dopamine neurons