DOPPLER CORRECTION FOR DIGITAL MODULATION IN A FADING CHANNEL WITH SINGLE-INPUT SINGLE-OUTPUT

In a high mobility wireless channel, the Doppler effect is compounded and must be corrected by using pilot-aided symbols. The pilot symbol rate depends on the severity of the Doppler effect. There are existing algorithms such as differential decision-feedback (D-DF) and double-differential decision-feedback (DD-DF) for single-input single output (SISO) systems to improve channel tap estimation. Such algorithms improve the bit error rate (BER) performance of pilot symbol aided decision feedback demodulation. In this thesis, the use of minimum mean square error (MMSE) estimation was implemented to further improve channel tap estimation for the D-DF and DD-DF algorithms. BER performance showed significant improvement for higher order modulation schemes. On the other hand, implementation of the new algorithm on quadrature phase-shift keying (QPSK) showed negligible improvement. Also, the MMSE algorithm is not very effective for cases with very high Doppler frequency shifts. Finally, it was observed that the performance improvement due to MMSE estimation decreases as the signal to-noise ratio increases. To counter this, adaptive tolerances, tied to the variance of channel tap estimation, were found to provide better channel estimation surge detection capabilities. Such implementation dramatically improved the bit error rate performances for D-DF with the MMSE algorithm but was not effective for the DD-DF algorithm.Military Expert 5, Republic of Singapore Air ForceApproved for public release; distribution is unlimited

Population Aging and Intergenerational Transfers: Introducing Age into National Accounts

In all societies intergenerational transfers are large and have an important influence on inequality and growth. The development of each generation of youth depends on the resources that it receives from productive members of society for health, education, and sustenance. The well-being of the elderly depends on familial support and a variety of social programs. The National Transfer Accounts (NTA) system provides a comprehensive approach to measuring all reallocations of income across age and time at the aggregate level. It encompasses reallocations achieved through capital accumulation and transfers, distinguishing those mediated by public institutions from those relying on private institutions. This paper introduces the methodology and presents preliminary results emphasizing economic support systems in Taiwan and the United States. As the two economies differ in their demographic configuration, their level of development, and their old-age support systems, comparing them will shed light on the economic implications of population aging under alternative institutional arrangements.

Identifying and categorising profane words in hate speech

This study attempts to explore the different types of Hate Speech appearing in social media by identifying profane words used in hate speech. This study also compares the profane words used in different generations to assist in identifying the user's profile. Five-hundred (500) comments posted on YouTube on the abusive topics were collected. Profane words are classified into eight different types of hate speech. The finding shows 35% of profane words found in our sample are words related to sexual orientation. Comparison of the terms between 1970 and 2017 also show a high percentage of profane words are sexual orientation. Though the results are found based on only 500 comments collected from YouTube link in the current study, they are useful in establishing the list of profane words which will serve as the base for automatic hate speech identification in our future study. The originality of this research is the development of a training list of profane words for each category and comparison of the type of the words used in 1970 century with today's social media platform

Genomic analysis of mouse tumorigenesis

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2006.Includes bibliographical references.The availability of the human and mouse genome sequences has spurred a growing interest in analyzing mouse models of human cancer using genomic techniques. Comparative genomic studies on mouse and human tumors can be valuable in two major ways: in validating mouse models and in identifying genes that are common to mouse and human tumorigenesis. Many analytic tools have emerged in recent years for human genome mining. Some of these tools have been translated to the murine versions. The work in this thesis described the application of two new whole-genome analytic techniques to study mouse tumorigensis: Representational Oligonucleotide Microarray Analysis (ROMA) for tumor DNA copy number asessment and single nucleotide polymorphism (SNP) genotyping using the SNaPshotM system (Applied Biosystems) to detect loss of heterozygosity (LOH) in mouse tumors. The murine version of ROMA was tested on DNA from early-stage KrasGJ2D-derived lung cancers and metastatic retinoblastoma in mice with retinal-specific Rb and p130 deletions. We were interested in identifying the additional genetic lesions that got positively selected during tumorigenesis of these mice.(cont.) Several recurrent chromosomal copy number gains and losses were observed in the DNA of KrasGJ2D-derived lung tumors. In addition, a focal amplification of the murine N-Myc locus was detected in the metastatic retinoblastomas, demonstrating the capability of ROMA to detect copy number changes at a single-gene resolution. For genome-wide allelotyping, a panel of 147 mouse SNPs were individually validated in 129S4/SvJae vs. C57BL/6J strains and were chosen as markers in the genotyping panel. We worked out a multiplex protocol to genotype the SNPs in an efficient manner. Through this protocol, we generated low-density global LOH maps of lung tumors from mice expressing KrasG12D. LOH that spanned entire chromosomes was seen in a subset of the tumors. A loss of the wild-type p53 allele was also observed in some cases.by Mandy Chi-Mun Tam.Ph.D

Establishment, Regeneration, and Succession of Korean Red Pine (Pinus densiflora S. et Z.) Forest in Korea

Seed production of Korean red pine (Pinus densiflora Siebold & Zucc.) was ranging from 25 to 27 seeds/m2 with a viability averaging between 42 and 44%. Seed dispersal reaches about 80 m. Germination rate of seed varied from 19 to 90%, and survival rate of seedling varied from 0 to 30% depending on moisture condition in field experiment. Survivorship curve of the pine population showed type III. Species composition of the pine forest was characterized by possessing plants with resistant capacity to water deficit such as Rhododendron micranthum, Vaccinium hirtum var. koreanum, Spodiopogon sibiricus, and Lespedeza cyrtobotrya. Ecological longevity of the pine was about 140 years based on mean age of gap makers. Natural maintenance of the pine forest depended on disturbance regime, which is dominated by endogenous factor. Natural regeneration of the pine forest is possible only in a very restricted site such as ridgetop with thin and infertile soil condition. Therefore, active and systematic management is required for artificial regeneration of the forest as is known in silivicultural method. Pine gall midge damage accelerated succession of the pine forest to the deciduous broadleaved forest dominated by oak except on the ridgetop where the forest can be maintained naturally

Genotoxicity Assessment of Multispecies Probiotics Using Reverse Mutation, Mammalian Chromosomal Aberration, and Rodent Micronucleus Tests

Genotoxicity assessment is carried out on freeze dried powder of cultured probiotics containing Lactobacillus rhamnosus LCR177, Bifidobacterium adolescentis BA286, and Pediococcus acidilactici PA318. Ames tests, in vitro mammalian chromosome aberration assay, and micronucleus tests in mouse peripheral blood are performed. For 5 strains of Salmonella Typhimurium, the Ames tests show no increased reverse mutation upon exposure to the test substance. In CHO cells, the frequency of chromosome aberration does not increase in responding to the treatment of probiotics. Likewise, the frequency of micronucleated reticulocytes in probiotics-fed mice is indistinguishable from that in the negative control group. Taken together, the toxicity assessment studies suggest that the multispecies probiotic mixture does not have mutagenic effects on various organisms

GScluster: Network-weighted gene-set clustering analysis

Background: Gene-set analysis (GSA) has been commonly used to identify significantly altered pathways or functions from omics data. However, GSA often yields a long list of gene-sets, necessitating efficient post-processing for improved interpretation. Existing methods cluster the gene-sets based on the extent of their overlap to summarize the GSA results without considering interactions between gene-sets. Results: Here, we presented a novel network-weighted gene-set clustering that incorporates both the gene-set overlap and protein-protein interaction (PPI) networks. Three examples were demonstrated for microarray gene expression, GWAS summary, and RNA-sequencing data to which different GSA methods were applied. These examples as well as a global analysis show that the proposed method increases PPI densities and functional relevance of the resulting clusters. Additionally, distinct properties of gene-set distance measures were compared. The methods are implemented as an R/Shiny package GScluster that provides gene-set clustering and diverse functions for visualization of gene-sets and PPI networks. Conclusions: Network-weighted gene-set clustering provides functionally more relevant gene-set clusters and related network analysis

Biclustering analysis of transcriptome big data identifies condition-specific microRNA targets

We present a novel approach to identify human microRNA (miRNA) regulatory modules (mRNA targets and relevant cell conditions) by biclustering a large collection of mRNA fold-change data for sequence-specific targets. Bicluster targets were assessed using validated messenger RNA (mRNA) targets and exhibited on an average 17.0% (median 19.4%) improved gain in certainty (sensitivity + specificity). The net gain was further increased up to 32.0% (median 33.4%) by incorporating functional networks of targets. We analyzed cancer-specific biclusters and found that the PI3K/Akt signaling pathway is strongly enriched with targets of a few miRNAs in breast cancer and diffuse large B-cell lymphoma. Indeed, five independent prognostic miRNAs were identified, and repression of bicluster targets and pathway activity by miR-29 was experimentally validated. In total, 29 898 biclusters for 459 human miRNAs were collected in the BiMIR database where biclusters are searchable for miRNAs, tissues, diseases, keywords and target genes