758 research outputs found

    Business Communication Curriculum: Where Has it Been?, Where is it Now?, and Where is it Going?

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    Business communication curriculum plays an integral role in preparing students for the workforce. In order for students to succeed in the ever-changing world of business, the business communication curriculum must reflect the current trends that are being accepted in the business world. This article reviews studies conducted during the past 30 years that have reviewed what has been included in the curriculum and what employers have expected from incoming employees. This article discusses the purpose and philosophy of business communication and developing a business communication curriculum, which includes what has been included in the curriculum in the past, what is currently being included in the curriculum, and what should be included in the curriculum in the future

    Femtosecond frequency comb measurement of absolute frequencies and hyperfine coupling constants in cesium vapor

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    We report measurements of absolute transition frequencies and hyperfine coupling constants for the 8S_{1/2}, 9S_{1/2}, 7D_{3/2}, and 7D_{5/2} states in ^{133}Cs vapor. The stepwise excitation through either the 6P_{1/2} or 6P_{3/2} intermediate state is performed directly with broadband laser light from a stabilized femtosecond laser optical-frequency comb. The laser beam is split, counter-propagated and focused into a room-temperature Cs vapor cell. The repetition rate of the frequency comb is scanned and we detect the fluorescence on the 7P_{1/2,3/2} -> 6S_{1/2} branches of the decay of the excited states. The excitations to the different states are isolated by the introduction of narrow-bandwidth interference filters in the laser beam paths. Using a nonlinear least-squares method we find measurements of transition frequencies and hyperfine coupling constants that are in agreement with other recent measurements for the 8S state and provide improvement by two orders of magnitude over previously published results for the 9S and 7D states.Comment: 14 pages, 14 figure

    Time series classification with ensembles of elastic distance measures

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    Several alternative distance measures for comparing time series have recently been proposed and evaluated on time series classification (TSC) problems. These include variants of dynamic time warping (DTW), such as weighted and derivative DTW, and edit distance-based measures, including longest common subsequence, edit distance with real penalty, time warp with edit, and move–split–merge. These measures have the common characteristic that they operate in the time domain and compensate for potential localised misalignment through some elastic adjustment. Our aim is to experimentally test two hypotheses related to these distance measures. Firstly, we test whether there is any significant difference in accuracy for TSC problems between nearest neighbour classifiers using these distance measures. Secondly, we test whether combining these elastic distance measures through simple ensemble schemes gives significantly better accuracy. We test these hypotheses by carrying out one of the largest experimental studies ever conducted into time series classification. Our first key finding is that there is no significant difference between the elastic distance measures in terms of classification accuracy on our data sets. Our second finding, and the major contribution of this work, is to define an ensemble classifier that significantly outperforms the individual classifiers. We also demonstrate that the ensemble is more accurate than approaches not based in the time domain. Nearly all TSC papers in the data mining literature cite DTW (with warping window set through cross validation) as the benchmark for comparison. We believe that our ensemble is the first ever classifier to significantly outperform DTW and as such raises the bar for future work in this area

    Characterization and Quantification of Isoprene-Derived Epoxydiols in Ambient Aerosol in the Southeastern United States

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    Isoprene-derived epoxydiols (IEPOX) are identified in ambient aerosol samples for the first time, together with other previously identified isoprene tracers (i.e., 2-methyltetrols, 2-methylglyceric acid, C5-alkenetriols, and organosulfate derivatives of 2-methyltetrols). Fine ambient aerosol collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS) was analyzed using both gas chromatography/quadrupole mass spectrometry (GC/MS) and gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) with prior trimethylsilylation. Mass concentrations of IEPOX ranged from ~1 to 24 ng m^(−3) in the aerosol collected from the two sites. Detection of particle-phase IEPOX in the AMIGAS samples supports recent laboratory results that gas-phase IEPOX produced from the photooxidation of isoprene under low-NO_x conditions is a key precursor of ambient isoprene secondary organic aerosol (SOA) formation. On average, the sum of the mass concentrations of IEPOX and the measured isoprene SOA tracers accounted for about 3% of the organic carbon, demonstrating the significance of isoprene oxidation to the formation of ambient aerosol in this region

    On the segmentation and classification of hand radiographs

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    This research is part of a wider project to build predictive models of bone age using hand radiograph images. We examine ways of finding the outline of a hand from an X-ray as the first stage in segmenting the image into constituent bones. We assess a variety of algorithms including contouring, which has not previously been used in this context. We introduce a novel ensemble algorithm for combining outlines using two voting schemes, a likelihood ratio test and dynamic time warping (DTW). Our goal is to minimize the human intervention required, hence we investigate alternative ways of training a classifier to determine whether an outline is in fact correct or not. We evaluate outlining and classification on a set of 1370 images. We conclude that ensembling with DTW improves performance of all outlining algorithms, that the contouring algorithm used with the DTW ensemble performs the best of those assessed, and that the most effective classifier of hand outlines assessed is a random forest applied to outlines transformed into principal components

    Doctor of Philosophy

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    dissertationEwing sarcoma is a malignant disease of young people that arises most frequently in bones of the femur and pelvis. The disease most often afflicts adolescents, creating physical, emotional and developmental challenges during an individual's most formative years. Mainstays of therapy include surgery and chemotherapy, meaning that survival may come at very high costs - amputation and lifelong disability. Those whose suffer metastasis or relapse must confront a poor prognosis. This is due in part to a lack of effective therapeutic options capable of destroying cancer at the cellular and molecular levels. To this end, molecular research continues to pursue greater understanding of the underlying biology of these tumors. The principal genetic lesion in Ewing sarcoma is a translocation that fuses chromosomes 11 and 22, giving rise to an oncogenic fusion protein known as EWS/FLI. EWS/FLI causes massive transcriptional misregulation, generating a gene expression program that transforms cells into cancer. Studies of transcriptional consequences of EWS/FLI misregulation have identified numerous genes that are necessary - but not sufficient - for tumorigenesis of Ewing sarcoma. These efforts have produced several candidates for molecular therapies for this malignancy, but no new therapies have yet reached the clinic. Research continues this pursuit, and hope persists. The work presented in this thesis is some of the first efforts to investigate the metabolic underpinnings of Ewing sarcoma. Specifically, these data provide preliminary insights into the effects that EWS/FLI has on misregulating metabolism, generating a program of biosynthesis that promotes and/or contributes to oncogenesis in these tumors. Numerous metabolic pathways are altered upon silencing of EWS/FLI, suggesting that EWS/FLI drives expression changes of key enzymes involved in metabolic processes. These data appear to indicate that generating a pro-oncogenic metabolic program is a key part of how EWS/FLI drives oncogenesis. Due to the fact that metabolic enzymes are generally amenable to pharmacological modulation, these findings offer new hope to the pursuit of a molecular therapy for Ewing sarcoma

    Properties of a Novel Ion-Exchange Film

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    A new ion-exchange material (based on polyacrylic acid) and some of its analytical applications have been reported. This paper contains data on the ion-exchange properties of the film form of the material and its potential application to the decontamination of waste water and drinking water. The film has a high exchange capacity of 5 to 6 meq/g and a pK(sub a) of 5.7. The calcium form is the most effective for removing metal ions from solution, and the optimum pH range is between 5 and 7. The exchange rates are slower for the film than for bead and powder forms of the ion-exchange material; otherwise, the properties are similar. The film is effective when hard water solutions are employed and also when metal ions are in the complex matrix of waste water from electroplating. The film can be used in flow systems having a flow channel large enough to allow passage of turbid solutions
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