Supersonic airplane design optimization method for aerodynamic performance and low sonic boom

This paper presents a new methodology for the optimization of supersonic airplane designs to meet the dual design objectives of low sonic boom and high aerodynamic performance. Two sets of design parameters are used on an existing High Speed Civil Transport (HSCT) configuration to maximize the aerodynamic performance and minimize the sonic boom under the flight track. One set of the parameters perturbs the camber line of the wing sections to maximize the lift-over-drag ratio (L/D). A preliminary optimization run yielded a 3.75 percent improvement in L/D over a baseline low-boom configuration. The other set of parameters modifies the fuselage area to achieve a target F-function. Starting from an initial configuration with strong bow, wing, and tail shocks, a modified design with a flat-top signature is obtained. The methods presented can easily incorporate other design variables and objective functions. Extensions to the present capability in progress are described

Application of CFD to sonic boom near and mid flow-field prediction

A 3-D parabolized Navier-Stokes (PNS) code was used to calculate the supersonic overpressures from three different geometries at near- and mid-flow fields. Wind tunnel data is used for code validation. Comparison of the computed results with different grid refinements is shown. It is observed that a large number of grid points is needed to resolve the tail shock/expansion fan interaction. Therefore, an adaptive grid approach is employed to calculate the flow field. The agreement between the numerical results and the wind tunnel data confirms that computational fluid dynamics can be applied to the problem of sonic boom prediction

Theories of astigmatism

Patients with astigmatism are encountered virtually every day by practicing clinicians. This paper consists of an extensive literature review of the theories of astigmatism development, from both a mechanical and functional aspect. It is a goal of this work to present a broad view of the field which can be useful in day to day encounters with astigmatic patients

Challenges and complexities in application of LCA approaches in the case of ICT for a sustainable future

In this work, three of many ICT-specific challenges of LCA are discussed. First, the inconsistency versus uncertainty is reviewed with regard to the meta-technological nature of ICT. As an example, the semiconductor technologies are used to highlight the complexities especially with respect to energy and water consumption. The need for specific representations and metric to separately assess products and technologies is discussed. It is highlighted that applying product-oriented approaches would result in abandoning or disfavoring of new technologies that could otherwise help toward a better world. Second, several believed-untouchable hot spots are highlighted to emphasize on their importance and footprint. The list includes, but not limited to, i) User Computer-Interfaces (UCIs), especially screens and displays, ii) Network-Computer Interlaces (NCIs), such as electronic and optical ports, and iii) electricity power interfaces. In addition, considering cross-regional social and economic impacts, and also taking into account the marketing nature of the need for many ICT's product and services in both forms of hardware and software, the complexity of End of Life (EoL) stage of ICT products, technologies, and services is explored. Finally, the impact of smart management and intelligence, and in general software, in ICT solutions and products is highlighted. In particular, it is observed that, even using the same technology, the significance of software could be highly variable depending on the level of intelligence and awareness deployed. With examples from an interconnected network of data centers managed using Dynamic Voltage and Frequency Scaling (DVFS) technology and smart cooling systems, it is shown that the unadjusted assessments could be highly uncertain, and even inconsistent, in calculating the management component's significance on the ICT impacts.Comment: 10 pages. Preprint/Accepted of a paper submitted to the ICT4S Conferenc

Analisis Filogenetik Gen gyrA dan gyrB dari Genus Mesorhizobium, Rhizobium dan Ensifer

Nucleotide sequence of gyrA and gyrB genes encoding subunit A and B of gyrase enzyme from genus of Rhizobium, Ensifer and Mesorhizobium were analyzed to determine evolutionary relationship among them. Maximum Likelihood  and Kimura 2 parameter methods were used to construct phylogenetic tree and measure genetic distance. Phylogenetic tree based on nucleotide sequence of gyrA gene was compared to phylogenetic tree based on nucleotide sequence of gyrB gene. Comparison of identity percentage among nucleotide sequence of gyrA gene from genus Rhizobium, Ensifer and Mesorhizobium show similarity, where each of them have narrow range of identity percentage, however nucleotide sequence of gyrB gene from genus Rhizobium and Ensifer show wider identity percentage range than genus Mesorhizobium.  Several member of genus Rhizobium and Ensifer have double copy of gyrB gene with identity percentage less than 50 percent between them. Topology of phylogenetic tree based on nucleotide sequence of gyrA gene have similar topology to topology of phylogenetic tree based on nucleotide sequence of gyrB gene, except for additional branch formed by one of additional copy of gyrB sequences.

What is CLS and Why Do They Say Such Terrible Things about it?

This paper argues that the category “Commonwealth literature” represents a vision and a future art, not a body of literature shaped by a common tradition. It discusses the vision that guided Commonwealth Literary Studies at its inception and analyses the problems that got in the way of this vision becoming a reality

Stimulus Complexity and Categorical Effects in Human Auditory Cortex: An Activation Likelihood Estimation Meta-Analysis

Investigations of the functional organization of human auditory cortex typically examine responses to different sound categories. An alternative approach is to characterize sounds with respect to their amount of variation in the time and frequency domains (i.e., spectral and temporal complexity). Although the vast majority of published studies examine contrasts between discrete sound categories, an alternative complexity-based taxonomy can be evaluated through meta-analysis. In a quantitative meta-analysis of 58 auditory neuroimaging studies, we examined the evidence supporting current models of functional specialization for auditory processing using grouping criteria based on either categories or spectro-temporal complexity. Consistent with current models, analyses based on typical sound categories revealed hierarchical auditory organization and left-lateralized responses to speech sounds, with high speech sensitivity in the left anterior superior temporal cortex. Classification of contrasts based on spectro-temporal complexity, on the other hand, revealed a striking within-hemisphere dissociation in which caudo-lateral temporal regions in auditory cortex showed greater sensitivity to spectral changes, while anterior superior temporal cortical areas were more sensitive to temporal variation, consistent with recent findings in animal models. The meta-analysis thus suggests that spectro-temporal acoustic complexity represents a useful alternative taxonomy to investigate the functional organization of human auditory cortex