Empirical prior latent Dirichlet allocation model

In this study, empirical prior Dirichlet allocation (epLDA) model that uses latent semantic indexing framework to derive the priors required for topics computation from data is presented. The parameters of the priors so obtained are related to the parameters of the conventional LDA model using exponential function. The model was implemented and tested with benchmarked data and it achieves a prediction accuracy of 92.15%. It was observed that the epLDA model consistently outperforms the conventional LDA model on different datasets with an average percentage accuracy of 6.33%; this clearly demonstrates the advantage of using side information obtained from data for the computation of the mixture components.Keywords: latent Dirichlet allocation; semantic indexing; empirical prior; hidden structures; Prediction accurac

Passions around Pheochromocytoma

Scientific adviser: ass. prof. Petrenko E.V. Head of department: prof. Yabluchansky M.I

Prevalence of Strongyle

Gastrointestinal parasitism is one of the major health problems affecting productivity of small ruminants worldwide. A dry season study was undertaken to determine the prevalence of Strongyle ova in goats and their faecal egg counts, as well as to compare different faecal culture methods for larval counts and identification. Out of 200 faecal samples examined, 114 were from male and 86 from female goats. An overall prevalence of 42(21%) for Strongyle ova was observed with a mean EPG of 91.67 + 6.12. The prevalence was higher in the male 26(22.8%) than in female 16(18.6%) with mean EPG of 90.38 ± 7.35 and 93.75 ± 11.06 respectively (p > 0.05). It was also higher in adults 38(22.22%) compared with the young 4(13.79%). All positive goats were of the Sahelian breed. No significant difference (p > 0.05%) was observed between sexes and age but a significant difference (p < 0.05) was observed between breeds. The infection was higher from samples collected in the abattoir 36 (25.35%) compared with 6(18.75%) in Mairi Village and none was positive from the University of Maiduguri Farm. A significant difference (p<0.05) was thus observed between locations. Only Strongyle ova was seen throughout the study and on subjection of the positive samples to larval recovery, Oesophagostomum columbianum was the only larva recovered. The test tube method yielded the highest larval recovery with mean larval count of 9.14 + 0.72 (p<0.05), compared with bottle with no charcoal; bottle with charcoal and Baermann’s techniques.Keywords: Goats, Strongyle ova, Faecal Culture Techniques, Prevalenc

Optimisation of Cellular Network System using Frequency-Reuse Technique

This paper presents a technique called “Channel Reuse” that can be employed by cellular network operators as an antidote to the challenges of limited channels in radio communication. This frequency reuse plays a key role in improving system capacity and spectral efficiency. In order to realise this, a simulated work has been carried out aimed at providing mobile telephone services to 32,000 subscribers within a landmass area of 4 Km2 using only 500 channels. This has been implemented using winprop software. In addition, an analytical solution has equally been proffered to complement the simulated work. The overall results show that for efficient cellular radio communication system, a good engineering design work is necessary in order to guarantee good signal quality, wider coverage, stem dropped call and call failure rate. Keywords: Frequency reuse, co-channel interference, cellular system, traffi

Adaptive spam filterings system using complement naive bayes model

Naïve bayes filter is a simple probabilistic filtering method based on Bayes theorem. A crucial problem with the conventional naïve bayes filter is the assumption of uniform priors in the computation of the posterior distribution. For online data such as email environment where the training data are constantly updated so as to outsmart the tricks of spammers, the prior knowledge cannot be uniform. Skewedness in the prior knowledge caused by the updated information has been reported to affect the accuracy and then the effectiveness of the traditional naïve bayes filter. In this study, the skewedness is addressed using complement naïve bayes model. The complement naïve bayes model was implemented and tested on benchmarked data and the result compared with the results obtained with the results obtained from the conventional naïve bayes filter on the same dataset. The complement naïve bayes based filter outperforms the conventional naïve bayes filter by 5.39%.Keywords: Spam, Spam filtering, complement naïve bayes, adaptive filtering, prior, bias, accuracy, filter, adaptive, skewednessVol. 26, No 1, June, 201

Passions around Pheochromocytoma

Scientific adviser: ass. prof. Petrenko E.V. Head of department: prof. Yabluchansky M.I

An analysis of activities of bee hunters and beekeepers in Oyo State, Nigeria.

The study compared the socio-economic characteristics of bee hunters and beekeepers. It also compared the bee sting prevention techniques and problems the two categories of bee farmers encountered in bee farming. The population for the study is made up of both bee hunters and beekeepers. A snowball technique was used to select the bee hunters as there was no official record while the list of beekeepers was obtained from beekeepers association. A total of fifty respondents were selected for the study consisting of 20 bee hunters and 30 beekeepers. An interview schedule was used in collecting data from the bee hunters since it was assumed that majority of them might not be able to read and write, while a questionnaire was used in gathering information from the beekeepers since it was believed that they were literates. The finding of the study showed that 76.7% of beekeepers are below 51 years of age, while 30% of the bee hunters’ fall within this age category, majority (90%) of the two categories of bee farmers was male. The beekeepers have higher education than bee hunters. About 75.0% of bee hunters used no prevention methods against bee sting while 100.0% of the beekeepers used bees dress/suit. About 60% of the bee hunters cited sting as problem they encountered while 46.7% of the beekeepers cited inadequate working space. Also, the keepers had better yields and made more income than the bee hunters. Since majority of bee hunters did not make use of bee sting prevention methods while beekeepers made use of bee dress, bee hunters should be trained of the importance of using bee sting prevention methods and should also be encouraged to have their own farms and move from being a bee hunter to beekeeper.KEY WORDS: Bee hunters, Beekeepers, Hives, Honey

Development of a mobile airline reservation and payment system

Airline Reservation in developing countries is carried out either manually or electronically. Either methods, reservation and payment operations are done in piece-meal fashion; this is cost prohibitive, time consuming and tedious leading to inefficiency. We present an integrated mobile airline reservation and payment system. Ours is a Client/Proxy/Server system with the proxy layer serving as mobility-aware middle layer providing real-time self service support. The study shows that mobile technology is matured for airline operators in developing countries as an avenue to improve efficiency, reduce operation costs, improved revenue generation and provision of value-added customer service for airline passengers.mobile business; m-business; WML; wireless markup language; wireless application protocols; airline reservations; reservation payment systems; WAP; mobile communications; developing countries; cost reduction; inefficiency; proxy layers; real-time; self service; clients; servers; airline operators; revenue generation; added value; customer service; air passengers; travel industry; Nigeria; Afrijet; Lagos; electronic finance; e-finance.

Durability assessment of basalt fiber polymer as reinforcement to expanded clay concrete in harsh environment

Basalt fiber-reinforced polymer composites are receiving considerable attention as they represent a low-cost green source of raw materials. In most cases, fiber-reinforced polymer composites face harsh environments, such as chloride ions in coastal marine environments or cold regions with salt deicing. The resistance of fiber-reinforced polymers subjected to the above environments is critical for the safe design and application of such composites. This research aims to develop a framework to investigate the durability properties of the lightweight expanded clay basalt fiber polymer reinforced concrete exposed to the NaCl environment. The specified quantity of concrete structural elements was cured in its specified curing solution for 28-day curing period before testing. The main effect of micro silica is to enhance concrete strength and durability. Dispersed basalt fibers with 20 mm length and 1.6 percent volume were added to the concrete mixtures. The concrete beams were reinforced with 2 null 10 mm rebars as reinforcement while the concrete cylindrical columns were reinforced with dispersed chopped basalt fiber. The results show that addition of dispersed chopped basalt fiber in the concrete caused an increase in the flexural and compressive strength of the concrete structural elements. Micro silica enhanced the concrete strength even when immersed in NaCl solution. Basalt fiber and micro silica fume utilization enhanced the mechanical properties of the concrete

A new mode of mineral replacement reactions involving the synergy between fluid-induced solid-state diffusion and dissolution-reprecipitation: A case study of the replacement of bornite by copper sulfides

Mineral replacement reactions are one of the most important phenomena controlling the geochemical cycle of elements on Earth. In the early years, solid-state diffusion was proposed as the main mechanism for mineral replacement reactions, but over the past 20 years the importance of the coupled dissolution-reprecipitation (CDR) mechanism has been recognized. In the presence of a fluid phase and at low temperatures (e.g., <300 °C), CDR is the predominant mineral replacement process compared to relatively slow solid-state diffusion. However, in the present case study, we show that the rate of solid-state diffusion is comparable to the rate of CDR processes during the replacement of bornite (Cu5FeS4) by copper sulfides at 160–200 °C. The experiments initially produced chalcopyrite lamellae homogeneously distributed in the entire bornite grain, and each lamella was enveloped by digenite. The lamellae were formed by removing Fe3+ from bornite via solid-state diffusion, since there was no evidence for fluid entering the bornite grains during lamellae formation. An interesting discovery is that solid-state exsolution of chalcopyrite lamellae was induced by the bulk hydrothermal fluids surrounding the mineral grains, because in the absence of fluids under otherwise identical conditions, no exsolution occurred, and because the exsolution rate and lamellae size were sensitive to the composition of hydrothermal fluids. We hypothesize that this fluid-induced solid-state diffusion (FI-SSD) mechanism is made possible by the similar topology of the crystal structure of these phases. The solid-state diffusion of Fe3+ within bornite and across the resultant chalcopyrite and digenite phase boundaries is facilitated by the near-identical S framework. Parallel to and after lamellae exsolution, CDR reactions proceeded from the surface to the interior of the grains or along fractures, replacing chalcopyrite by digenite, and digenite by covellite and/or chalcocite, depending on experimental conditions. The synergy between FI-SSD and CDR resulted in complex reaction pathways for reactions in five acidic hydrothermal fluids with or without added Cu2+, Cu+, Cl−, SO42−, and SO32−. The outcomes of these experiments imply that (1) under conditions where cation diffusion rates are of the same order of magnitude as dissolution and precipitation rates, hydrothermal fluids can induce and control solid-state diffusion processes, e.g., exsolution; (2) mineral replacement can be a result of the synergy between FI-SSD and CDR mechanisms; this happens at low temperatures (≤200 °C) in chalcogenide systems, but could affect silicate and oxide systems at amphibolite to granulite to eclogitic metamorphic grade; and (3) the synergy between FI-SSD and CDR mechanisms can lead to complex reaction pathways that cannot be easily predicted empirically