Modeling Spammer Behavior: Artificial Neural Network vs. Naïve Bayesian Classifier

The exponential growth of spam emails in recent years is a fact of life. Internet subscribers world-wide are unwittingly paying an estimated €10 billion a year in connection costs just to receive “junk” emails, according to a study undertaken for the European Commission. Though there is no universal definition of spam, unwanted and unsolicited commercial email as a mass mailing to a large number of recipients is basically known as the junk email or spam to the internet community. Spams are considered to be potential threat to Internet Security. Spam's direct effects include the consumption of computer and network resources and the cost in human time and attention of dismissing unwanted messages. More importantly, these ever increasing spams are taking various forms and finding home not only in mailboxes but also in newsgroups, discussion forums etc without the consent of the recipients. Overflowing mailboxes are overwhelming users, causing newsgroups and discussion forums to be flooded with irrelevant or inappropriate messages. As a consequence, users are getting discouraged not to use them anymore though these systems can provide numerous benefits to them.Full Tex

Investigation into teachers’ practice in relation to curriculum implementation in ELT in Bangladesh

The study investigates teachers’ practices in relation to curriculum implementation in secondary level education in Bangladesh. The research examines five English language teachers’ classroom activities and compares if their activities are implemented as recommended by the curriculum. It also focuses on the factors that influence the teachers to implement the curriculum. The researcher conducted qualitative research to collect data for this study. As a result, the researcher made classroom observations to see the activities of the teachers in the classroom and conducted interviews afterwards to understand what factors influence the teachers. The analysis of the study reveals that the teachers focus on part of the curriculum in their activities in the classroom. The interviews analysis reveals that the teachers’ activities are different from the recommended activities in the classroom. The result of the study showed that the teachers’ activities are not congruent with the principles of the curriculum as their activities are influenced by other contextual factors

Parallel evolution strategy for protein threading.

A protein-sequence folds into a specific shape in order to function in its aqueous state. If the primary sequence of a protein is given, what is its three dimensional structure? This is a long-standing problem in the field of molecular biology and it has large implication to drug design and cure. Among several proposed approaches, protein threading represents one of the most promising technique. The protein threading problem (PTP) is the problem of determining the three-dimensional structure of a given but arbitrary protein sequence from a set of known structures of other proteins. This problem is known to be NP-hard and current computational approaches to threading are time-consuming and data-intensive. In this thesis, we proposed an evolution strategy (ES) based approach for protein threading (EST). We also developed two parallel approaches for the PTP problem and both are parallelizations of our novel EST. The first method, we call SQST-PEST (Single Query Single Template Parallel EST) threads a single query against a single template. We use ES to find the best alignment between the query and the template, and ES is parallelized. The second method, we call SQMT-PEST (Single Query Multiple Templates Parallel EST) to allow for threading a single query against multiple templates within reasonable time. We obtained better results than current comparable approaches, as well as significant reduction in execution time.Dept. of Computer Science. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .I85. Source: Masters Abstracts International, Volume: 44-03, page: 1403. Thesis (M.Sc.)--University of Windsor (Canada), 2005

Genetic variability of submergence tolerance in rice related to yield and yield contributing traits: Submergence tolerance in rice

Twenty-three rice genotypes were evaluated during kharif II season for understanding the submergence tolerance associated with short-duration and high yielding traits. For this, relative performance of seven quantitative plant traits of the genotypes viz. days to maturity, panicles per hill, panicle weight, spikelets sterility, spikelets per panicle, 1000-seed weight and grain yield were analyzed under normal and submerged conditions. The genotypic variation was found in all the relative plant traits. Multivariate techniques viz. k-means cluster analysis and discriminant function analysis (DFA) were used for grouping the genotypes. Maximum number of genotypes (15) were grouped in cluster 3 followed by cluster 1 (4). The genotype BRRI dhan31, BRRI dhan39, BRRI dhan56 and BRRI dhan57 under cluster 1 performed better compared to other cluster members. DFA showed that function 1 and 2 explained 80.5 percent and 16.9 percent respectively with a cumulative of 97.4 percent of total variance of the genotypes. Panicles per hill, panicle weight, sterility percent, 1000-grain weight and grain yield mostly contributed in grouping the genotypes. The panicle weight followed by grain yield played the major role for the maximum variance in the genotypes. The results suggest that the short-duration genotypes BRRI dhan33 and BRRI dhan56 and BRRI dhan57 performed better under submerged condition and the plant traits like panicle weight or grain yield could be the best choice for submergence tolerance in rice

Microcredit - A More Credible Social than Economic Program in Bangladesh

Calculated under the framework of economic-profit counting, the productivity of microcredit in Bangladesh is found very low. In this survey about 48% of the borrowers had to compromise their normal wages for self-employed labor to be able to pay the high interest for the credit. Similarly its social productivity is also found marginal. However, about 90% of the borrowers felt comfortable with microcredit even at so high interest rate seemingly to avoid losing or compromising their social and political empowerment at the hands of the local moneylenders or relatives. Borrowers give high value to their socio-political empowerments and are ready to compromise normal wages for their self-employed labor. In the game of political economy of credit for the poor, microcredit is seen as a means of protecting and enhancing socio-political empowerments of the low income and distressed people in the society and is appraised as a credible social than economic institution.Grameen Bank, microcredit, microenterprise, subsistent, poverty alleviation, stereotype, empowerment

Genetic analysis of specific and non-specific immune response in Oreochomis niloticus L.

Gynogenesis or androgenesis were used to produce completely homozygous inbred tish, from which clonal lines were established by subsequent gynogenesis, androgenesis and sib mating. Homozygosity of the inbred lines was verified using multilocus DNA fingerprinting and isozyme locus ADA*, which showed all gynogenetic offspring to have only maternal inheritance. DNA fingerprints of meiotic and mitotic gynogens showed bands consistent with those of their mother but not of their father. Inbred clones also showed identical banding patterns with their mitotic mother and not their father. The outbred clones, in contrast, shared bands with both parents according to Mendelian inheritance. Sex ratios of both meiotic and mitotic gynogenetics were analysed and a significantly higher number of females (P<0.05) were found in both gynogenetic groups. All inbred clones, except one line, were 100% females. MHC class II B genotypes of the clonal lines were determined by PCR. Scale grafting was carried out between clonal lines where two sets of grafts were reciprocally exchanged. Both .sets of grafts were completely rejected by reciprocal recipient fish. The mean survival time of the .second set of grafts was significantly shorter than that of the first set. This suggested that the differences in the MHC haplotypes of different clonal lines exerted strong alloantigenic effects on the foreign grafts which led to their rejection and memory in immune system. Non-specific immune re.spon.se of different inbred and outbred clonal lines was examined by analysing an array of immunological parameters. Significantly different SCI urn lysozyme activity (P 10 phagocytosed bacteria between the different groups. In the artificial challenge, significantly different susceptibility to A. hydrophilci infection was found between inbred clonal lines. The outbred clonal lines showed an intermediate infection level between that of their parents, and their disease resistance was higher than that of the lea.st resistant parent. The artificial challenge results revealed that there was a genetic difference in the disease resistance between different clonal groups of fish. It also suggested that disease resistance of an outbred population might be improved by crossbreeding

Effect of shadowing and diffraction on the received GNSS signal

Abstract. The characteristics of the GNSS received signal depend on the propagation medium environment. Typically, the transmitted signal interacts with several numbers of obstacles which leads to the multipath propagation to receiver end. In such cases, diffraction over the edges or wedges of the obstacles in the propagation path should be considered. The effects of diffraction and shadowing are the important elements in radio wave propagation because of their strong influence on the received signal quality. Especially, received signal strength and characteristics are very significant for GNSS applications. This master’s thesis investigates the effect of knife-edge diffraction model and shadowing environment on the received GNSS signal. Characterization of the received signal is investigated both theoretically and experimentally. In the measurement, a dual circular polarized antenna has been used to receive the multipath GPS signal in the shadow region in which antenna was placed in the zenith direction. The measurement was performed for two scenarios 1) the receiver was in the static position, and 2) in motion for the second measurement. Measurement results show that, the received signals following the Knife-edge diffraction pattern for both measurements case. In the first measurement case, knife-edge diffraction has been identified in received signal attenuation whereas the interference pattern in the LoS propagation can be observed because of multipath effect. In the deep shadow region, a linearly polarized signal has been received in both antennas because the incident RHCP signal turned into a linearly polarized signal after diffraction. For the second measurement case, knife-edge attenuation pattern is also visible. A clear agreement between the measured and theoretical aspects has been achieved in the case of knife-edge diffraction