Optimization of Fast-Decodable Full-Rate STBC with Non-Vanishing Determinants

Full-rate STBC (space-time block codes) with non-vanishing determinants achieve the optimal diversity-multiplexing tradeoff but incur high decoding complexity. To permit fast decoding, Sezginer, Sari and Biglieri proposed an STBC structure with special QR decomposition characteristics. In this paper, we adopt a simplified form of this fast-decodable code structure and present a new way to optimize the code analytically. We show that the signal constellation topology (such as QAM, APSK, or PSK) has a critical impact on the existence of non-vanishing determinants of the full-rate STBC. In particular, we show for the first time that, in order for APSK-STBC to achieve non-vanishing determinant, an APSK constellation topology with constellation points lying on square grid and ring radius \sqrt{m^2+n^2} (m,n\emph{\emph{integers}}) needs to be used. For signal constellations with vanishing determinants, we present a methodology to analytically optimize the full-rate STBC at specific constellation dimension.Comment: Accepted by IEEE Transactions on Communication

Soil Matric Suction and Active Zone Depth in Oklahoma

Soil matric suction is an important parameter in unsaturated soils. The shrink-swell properties of expansive soils is controlled by soil matric suction. Matric suction variations cause volume change in expansive soils, which further causes damages to pavements and foundations. This research makes use of field measurements of matric suction obtained from the Oklahoma Mesonet and the Department of Energy�s Atmospheric Radiation Measurement network to estimate active zone depth. The long-term matric suction measurement indicated a seasonal pattern of matric suction variation. The shallower depth of soil is more sensitive to the climatic conditions. Two methodologies, empirical equation and numerical analysis, were used to calculate the active zone depth in Oklahoma. The active zone depth is approximately 0.5 to 4 m depending on the soil properties and climatic conditions. The diffusion coefficient and saturated hydraulic conductivity are the two important parameters controlling the active zone depth.Civil Engineerin

Assessing Eastern Redcedar Encroachment and Environmental Factors in Oklahoma by Remote Sensing and Gis

The study area in this project covers 16 contiguous counties, most of which are located in central and western Oklahoma. The maps and the shapefiles of eastern redcedar are from remote sensing imagery. I use ArcGIS and ERDAS to analyze the shapfiles and the imagery of the redcedar, land cover and the elevation. To examine the relationships between eastern redcedar and environmental factors and the land use, I build three regression models in SPSS. This research evaluates the relationships between eastern redcedar and environmental factors as well as the land use. The analysis of this research suggests that the herbaceous land cover and the variations in topography are important factors associated with eastern redcedar encroachment in Oklahoma. The type of herbaceous cover is the most easily encroached by eastern redcedar. The deciduous forest is another type that is also easily encroached by the cedars. The climate conditions (including average temperature and precipitation), open water, and the land use (cultivated crops) are not affected by eastern redcedar.Department of Geograph

INTERNATIONAL STUDENTS' PATHWAY: MAINLAND CHINESE STUDENTS IN SINGAPORE

Master'sMASTER OF SOCIAL SCIENCE

High optical transmittance of aluminum ultrathin film with hexagonal nanohole arrays as transparent electrode

We fabricate samples of aluminum ultrathin films with hexagonal nanohole arrays and characterize the transmission performance. High optical transmittance larger than 60% over a broad wavelength range from 430 nm to 750 nm is attained experimentally. The Fano-type resonance of the excited surface plasmon plaritons and the directly transmitted light attribute to both of the broadband transmission enhancement and the transmission suppression dips

The chromatic Point Spread Function of weak lensing measurement in Chinese Space Station survey Telescope

The weak gravitational lensing is a powerful tool in modern cosmology. To accurately measure the weak lensing signal, one has to control the systematic bias to a small level. One of the most difficult problems is how to correct the smearing effect of the Point Spread Function (PSF) on the shape of the galaxies. The chromaticity of PSF for a broad-band observation can lead to new subtle effects. Since the PSF is wavelength dependent and the spectrum energy distributions between stars and galaxies are different, the effective PSF measured from the star images will be different from that smears the galaxies. Such a bias is called colour bias. We estimate it in the optical bands of the Chinese Space Station Survey Telescope from simulated PSFs, and show the dependence on the colour and redshift of the galaxies. Moreover, due to the spatial variation of spectra over the galaxy image, there exists another higher-order bias, colour gradient bias. Our results show that both colour bias and colour gradient bias are generally below $0.1$ percent in CSST. Only for small-size galaxies, one needs to be careful about the colour gradient bias in the weak lensing analysis using CSST data

RNA-seq analysis of gene expression changes during pupariation in Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

Background: The oriental fruit fly, Bactrocera dorsalis (Hendel) has been considered to be one of the most important agricultural pest around the world. As a holometabolous insect, larvae must go through a metamorphosis process with dramatic morphological and structural changes to complete their development. To better understand the molecular mechanisms of these changes, RNA-seq of B. dorsalis from wandering stage (WS), late wandering stage (LWS) and white puparium stage (WPS) were performed. Results: In total, 11,721 transcripts were obtained, out of which 1914 genes (578 up-regulated and 1336 down-regulated) and 2047 genes (655 up-regulated and 1392 down-regulated) were found to be differentially expressed between WS and LWS, as well as between WS and WPS, respectively. Of these DEGs, 1862 and 1996 genes were successfully annotated in various databases. The analysis of RNA-seq data together with qRT-PCR validation indicated that during this transition, the genes in the oxidative phosphorylation pathway, and genes encoding P450s, serine protease inhibitor, and cuticular proteins were down-regulated, while the serine protease genes were up-regulated. Moreover, we found some 20-hydroxyecdysone (20E) biosynthesis and signaling pathway genes had a higher expression in the WS, while the genes responsible for juvenile hormone (JH) synthesis, degradation, signaling and transporter pathways were down-regulated, suggesting these genes might be involved in the process of larval pupariation in B. dorsalis. For the chitinolytic enzymes, the genes encoding chitinases (chitinase 2, chitinase 5, chitinase 8, and chitinase 10) and chitin deacetylase might play the crucial role in the degradation of insect chitin with their expressions significantly increased during the transition. Here, we also found that chitin synthase 1A might be involved in the chitin synthesis of cuticles during the metamorphosis in B. dorsalis. Conclusions: Significant changes at transcriptional level were identified during the larval pupariation of B. dorsalis. Importantly, we also obtained a vast quantity of RNA-seq data and identified metamorphosis associated genes, which would all help us to better understand the molecular mechanism of metamorphosis process in B. dorsalis

EVALUATION OF THE ENHANCED INTEGRATED CLIMATIC MODEL FOR SPECIFICATION OF SUBGRADE SOILS IN OKLAHOMA

The main objective of this study was to collect and evaluate climatic and soil data pertaining to Oklahoma for the climatic model (EICM) in the mechanistic-empirical design guide for pavements. The EICM climatic input files were updated and extended over a large area covering Oklahoma climatic conditions. Large cluster of raw climate and soil moisture data were obtained from the Oklahoma Mesonet for evaluation and use in creating the necessary input parameters for the climatic model. Historical climatic data were also employed for classifying climatic regions in Oklahoma using cluster analysis. Thornthwaite Moisture Index (TMI) contour maps were created using the climatic data and ArcGIS software. A comprehensive validation study was also undertaken in comparing the moisture migration processes in the EICM and commercially available software using the climatic and soil data in Oklahoma.Final report, October 2011-December 2013N