Multiplication Operators on Weighted Banach Spaces of a Tree

We study multiplication operators on the weighted Banach spaces of an infinite tree. We characterize the bounded and the compact operators, as well as determine the operator norm. In addition, we determine the spectrum of the bounded multiplication operators and characterize the isometries. Finally, we study the multiplication operators between the weighted Banach spaces and the Lipschitz space by characterizing the bounded and the compact operators, determine estimates on the operator norm, and show there are no isometries

A Model of Attitudes toward the Acceptance of Mobile Phone Use in Public Places

Since the first commercial launch of cellular telecoms by NET in Tokyo Japan in 1979 and the launch of the NMT system in Denmark, Finland, Norway and Sweden in 1981, the mobile phone has undergone continual incremental innovation for changing market needs. This study investigates the factors affecting the attitudes towards the social acceptance of mobile phones in public places and how this attitude affects its usage. Theories on innovation and technology acceptance were reviewed, and studies relating demographic factors to technology acceptance were examined. A model was proposed relating the usage frequency and attitudes towards acceptance of mobile phone in public places to demographic factors, such as country, age, education, gender, and work status. A survey was conducted among mobile phone users, and the sample consisted of 1079 respondents in the United States, France, Italy, Turkey, and Finland. A structural equation model was developed to analyze the survey data. Results of the analysis indicate that the attitudes about mobile phone use in public places depend on country, and age factors. This attitude in turn significantly affects the usage frequency of mobile phones. In addition, usage frequency also is affected by gender and work status. Implications of the findings for both academicians and practitioners are discussedAttitudes about Mobile Phone Use, Simultaneous Relationships, Demographic Factors, Mobile Phone Voice Messaging, Mobile Phone Text Messaging

TAXONOMY DEVELOPMENT IN INFORMATION SYSTEMS: DEVELOPING A TAXONOMY OF MOBILE APPLICATIONS

The complexity of the information systems field often lends itself to classification schemes, or taxonomies, which provide ways to understand the similarities and differences among objects under study. Developing a taxonomy, however, is a complex process that is often done in an ad hoc way. This research-in-progress paper uses the design science paradigm to develop a systematic method for taxonomy development in information systems. The method we propose uses an indicator or operational level model that combines both empirical to deductive and deductive to empirical approaches. We evaluate this method by using it to develop a taxonomy of mobile applications, which we have chosen because of their ever-increasing number and variety. The resulting taxonomy contains seven dimensions with fifteen characteristics. We demonstrate the usefulness of this taxonomy by analyzing a range of current and proposed mobile applications. From the results of this analysis we identify combinations of characteristics where applications are missing and thus are candidates for new and potentially useful applications.taxonomy, design science, mobile application

Influence of compaction energy on soil engineering properties

Strength and deformation parameters of compacted soil are known to be related to soil type and moisture content. However, little attention has been directed towards understanding the influence of compaction energy on these properties. This paper describes laboratory and field studies conducted to evaluate the relationship between soil type, soil moisture content, and compaction energy on seven cohesive soil types. In the lab, specimens were compacted with impact energy at levels of 355, 592 (standard Proctor), 987, 1643, and 2693 kJ/m³ (modified Proctor) over a wide range of moisture contents to determine dry unit weight, unconfined compressive strength and the secant (50 percent strain) stiffness. In total, 175 Proctor tests and 95 unconfined compression tests were performed. At each energy level, a soil was tested at 4 to 5 moisture contents with respect to its standard Proctor moisture range. In addition, 54 consolidated undrained triaxial tests were performed at the five energies and four moisture contents for one soil to evaluate changes in effective stress shear strength parameters. This paper summarizes the results of statistical analyses performed on all lab and field tests conducted. The models that best explain variability in dry unit weight, strength, and stiffness are presented. Models are presented individually for each soil type and also inclusive of all soils grouped together. Independent variables used in the modeling include compaction energy, moisture content, confining pressure, Atterberg limits, material passing the No. 200 sieve, and clay fraction. In addition, a new compaction model, derived from a linear rate equation, is presented and checked for validity in estimating soil dry unit weight as a function of compaction energy. Results indicate that compaction energy, combined with moisture content, is a key factor in determining soil strength and stiffness parameters. It is concluded that the strength and stability of a compacted soil cannot be assessed in terms of relative compaction alone. Instead, this research encourages the use of strength and stiffness in the design and construction phases of earthwork operations, being the true functional requirements for compaction specifications

Handling uncertainty in citizen science data: towards an improved amateur-based large-scale classification

© 2018 Citizen Science, traditionally known as the engagement of amateur participants in research, is showing great potential for large-scale processing of data. In areas such as astronomy, biology, or geo-sciences, where emerging technologies generate huge volumes of data, Citizen Science projects enable image classification at a rate not possible to accomplish by experts alone. However, this approach entails the spread of biases and uncertainty in the results, since participants involved are typically non-experts in the problem and hold variable skills. Consequently, the research community tends not to trust Citizen Science outcomes, claiming a generalised lack of accuracy and validation. We introduce a novel multi-stage approach to handle uncertainty within data labelled by amateurs in Citizen Science projects. Firstly, our method proposes a set of transformations that leverage the uncertainty in amateur classifications. Then, a hybridisation strategy provides the best aggregation of the transformed data for improving the quality and confidence in the results. As a case study, we consider the Galaxy Zoo, a project pursuing the labelling of galaxy images. A limited set of expert classifications allow us to validate the experiments, confirming that our approach is able to greatly boost accuracy and classify more images with respect to the state-of-art

Organizational Commitment and Turnover Intentions of Clinical Laboratory Scientists in Ghana

High employee turnover rate coupled with frequent strike actions embarked on by clinical laboratory scientists in Ghana over the years has become a major issue that needs to be addressed. This study examined the different dimensions of organizational commitment (affective, continuance and normative commitment) as predictors of turnover intentions of medical laboratory scientists in selected health facilities in Ghana. The study consisted of 141 medical laboratory scientists drawn from various public health institutions. Two standardized instruments were used to measure organisational commitment and turnover intentions. Results of the study revealed that turnover intentions correlated insignificantly with affective commitment, but correlated significantly with continuance commitment and negatively with normative commitment. Further analysis revealed a linear positive relationship between the predictor variables combined (affective commitment, continuance commitment, normative commitment) and criterion variable (turnover intentions) among clinical laboratory scientists. Based on the findings, retention strategies of clinical laboratory scientists were proposed. Key words: Organisational Commitment, Turnover Intentions, Clinical Laboratory Scientists

A cryogenic surface-electrode elliptical ion trap for quantum simulation

Two-dimensional crystals of trapped ions are a promising system with which to implement quantum simulations of challenging problems such as spin frustration. Here, we present a design for a surface-electrode elliptical ion trap which produces a 2-D ion crystal and is amenable to microfabrication, which would enable higher simulated coupling rates, as well as interactions based on magnetic forces generated by on-chip currents. Working in an 11 K cryogenic environment, we experimentally verify to within 5% a numerical model of the structure of ion crystals in the trap. We also explore the possibility of implementing quantum simulation using magnetic forces, and calculate J-coupling rates on the order of 10^3 / s for an ion crystal height of 10 microns, using a current of 1 A

Expression differences by continent of origin point to the immortalization process

Analysis of recently available microarray expression data sets obtained from immortalized cell lines of the individuals represented in the HapMap project have led to inconclusive comparisons across cohorts with different ancestral continent of origin (ACOO). To address this apparent inconsistency, we applied a novel approach to accentuate population-specific gene expression signatures for the CEU [homogeneous US residents with northern and western European ancestry (HapMap samples)] and YRI [homogenous Yoruba people of Ibadan, Nigeria (HapMap samples)] trios. In this report, we describe how four independent data sets point to the differential expression across ACOO of gene networks implicated in transforming the normal lymphoblast into immortalized lymphoblastoid cells. In particular, Werner syndrome helicase and related genes are differentially expressed between the YRI and CEU cohorts. We further demonstrate that these differences correlate with viral titer and that both the titer and expression differences are associated with ACOO. We use the 14 genes most differentially expressed to construct an ACOO-specific ‘immortalization network’ comprised of 40 genes, one of which show significant correlation with genomic variation (eQTL). The extent to which these measured group differences are due to differences in the immortalization procedures used for each group or reflect ACOO-specific biological differences remains to be determined. That the ACOO group differences in gene expression patterns may depend strongly on the process of transforming cells to establish immortalized lines should be considered in such comparisons