e-Collaboration for Tertiary Education Using Mobile Systems

Electronic collaboration has revolutionized academic activities by enabling academic collaborations through devices such ascomputers and other mobile devices. With this development, learning and academic collaboration can now take place acrosscontinents and different time zones. In electronic collaboration, knowledge sharing is done remotely, in real-time and notlocation-bound. Although several institutions in the developed countries have been using some form of eCollaboration foracademic activities and for improving collaborations among students, much has not been done in this domain in thedeveloping world. Using Java as software technology of choice, we take electronic learning a step further by making itpossible for students to learn and collaborate through mobile phones thus leveraging on the existing mobile diffusion amongstudents in Nigeria. The intention is to contribute to research and development in mobile learning relevant to the growth andquality of education by encouraging group participation among students and fostering joint academic contributions amongthe academia.KEYWORDS: Electronic collaboration, Mobile collaboration software, mobile phone and electronic learning

Analysis of radio frequency spectrum usage using cognitive radio

This paper presents the analysis of radio frequency (RF) spectrum usage using cognitive radio. The aim was to determine the unused spectrum frequency bands for efficiently utilization. A program was written to reuse a range of vacant frequency with different model element working together to produce a spectrum sensing in MATLAB/Simulink environment. The developed Simulink model was interfaced with a register transfer level - software defined radio, which measures the estimated noise power of the received signal over a given time and bandwidth. The threshold estimation performed generates a 1\0 output for decision and prediction. It was observed that some spectrum, identified as vacant frequency, were underutilized in FM station in Benin City. The result showed that when cognitive radio displays “1” output, which is decision H1, the channel is occupied and cannot be used by the cognitive radio for communication. Conversely, when “0” output (decision H0) is displayed, the channel is unoccupied. There is a gradual decrease in the probability of detection (Pd), when the probability of false alarm (Pfa) is increased from 1% to 5%. In the presence of higher Pfa, the Pd of the receiver maintains a high stability. Hence, the analysis finds the spectrum hole and identifies how it can be reuse

Women's role in reproductive health decision making and vulnerability to STD and HIV/AIDS in Ekiti, Nigeria

An exploratory study of women’s role in reproductive decision making in Ekiti shows that women in the state are increasingly taking active decisions on matters affecting their daily lives. More women than ever before believed that they could take decisions on family size, when to have a baby and choice of spacing period. The cultural barrier against short postpartum abstinence appeared to have diminished and sex during lactation was not considered a major cultural and religious taboo. Knowledge of contraception has become universal in recent years, and the majority of women take decisions on the method and timing of family planning. All women who used family planning considered their decision in this regard very important. The ability of women to take decisions on these issues may not only enhance their bargaining power but also reduce their vulnerability to STDs including AIDS from diseased or high-risk partners

Kinetic characterization of the critical step in HIV-1 protease maturation

HIV maturation requires multiple cleavage of long polyprotein chains into functional proteins that include the viral protease itself. Initial cleavage by the protease dimer occurs from within these precursors, and yet only a single protease monomer is embedded in each polyprotein chain. Self-activation has been proposed to start from a partially dimerized protease formed from monomers of different chains binding its own N termini by self-association to the active site, but a complete structural understanding of this critical step in HIV maturation is missing. Here, we captured the critical self-association of immature HIV-1 protease to its extended amino-terminal recognition motif using large-scale molecular dynamics simulations, thus confirming the postulated intramolecular mechanism in atomic detail. We show that self-association to a catalytically viable state requires structural cooperativity of the flexible β-hairpin “flap” regions of the enzyme and that the major transition pathway is first via self-association in the semiopen/open enzyme states, followed by enzyme conformational transition into a catalytically viable closed state. Furthermore, partial N-terminal threading can play a role in self-association, whereas wide opening of the flaps in concert with self-association is not observed. We estimate the association rate constant (k(on)) to be on the order of ∼1 × 10(4) s(−1), suggesting that N-terminal self-association is not the rate-limiting step in the process. The shown mechanism also provides an interesting example of molecular conformational transitions along the association pathway

Optimization of accurate estimation of single diode solar photovoltaic parameters and extraction of maximum power point under different conditions

Introduction. With the snowballing requirement of renewable resources of energy, solar energy has been an area of key concern to the increasing demand for electricity. Solar photovoltaic has gotten a considerable amount of consideration from researchers in recent years. Purpose. For generating nearly realistic curves for the solar cell model it is needed to estimate unknown parameters with utmost precision. The five unknown parameters include diode-ideality factor, shunt-resistance, photon-current, diode dark saturation current, and series-resistance. Novelty. The proposed research method hybridizes flower pollination algorithm with least square method to better estimate the unknown parameters, and produce more realistic curves. Methodology. The proposed method shows many promising results that are more realistic in nature, as compared to other methods. Shunt-resistance and series-resistance are considered and diode constant is not neglected in this approach that previously has been in practice. The values of series-resistance and diode-ideality factor are found using flower pollination algorithm while shunt-resistance, diode dark saturation current and photon-current are found through least square method. Results. The combination of these techniques has achieved better results compared to other techniques. The simulation studies are carried on MATLAB/Simulink.Вступ. З огляду на величезну потребу у відновлюваних енергетичних ресурсах, сонячна енергія стала ключовою сферою розв’язання проблеми зростання попиту на електроенергію. За останні роки сонячна фотоелектрична техніка отримала значну увагу з боку дослідників. Мета. Для створення майже реалістичних кривих для моделі сонячних батарей необхідно оцінити невідомі параметри з максимальною точністю. П'ять невідомих параметрів включають коефіцієнт ідеальності діодів, опір шунту, фотонний струм, струм темного насичення діодів і послідовний опір. Новизна. Запропонований метод дослідження поєднує алгоритм запилення квітів із методом найменших квадратів для кращої оцінки невідомих параметрів та отримання більш реалістичних кривих. Методологія. Запропонований метод демонструє багато перспективних результатів, які є більш реалістичними за своєю природою, порівняно з іншими методами. Розглянуто опір шунта і послідовний опір, і в цьому підході, який раніше застосовувався на практиці, не нехтують постійною діода. Значення послідовного опору та коефіцієнта ідеальності діодів визначаються за допомогою алгоритму запилення квіток, тоді як опір шунту, струм темного насичення діодів і фотонний струм - методом найменших квадратів. Результати. Поєднання цих методів забезпечило кращі результати у порівнянні з іншими методами. Моделювання проводиться на MATLAB/Simulink

The Preparation of some New Mannich and Shiff bases derived from 2-Mercaptobenzimidazole

The present work involved two steps: the first step include Mannich reaction was carried out on 2- mercaptobenzimidazole using formaldehyde and different secondary amine or amide to gives the compounds(2-16). The secnd step include preparation of (Ethylbenzimidazoly-2-mercaptoacetate)(17) from the reaction of 2- mercaptobenzimidazole with ethylchloroacetate than prepared hydrazide derivative[18]from reaction of compound(17) with hydrazinehydrate. Followed Preparation of shiff bases(19-24) and there reaction with mercaptoacetic acid to give a new compounds containing thiazolidinderivetives(25-30).Structure confirmation of all prepared compound were proved using FTIR and element analysis (C.H.N.S) and mesurmentedmelting point

Complexes of Some Transition Metal with 2-Benzoyl thiobenzimidazole and 1,10-Phenanthroline and Studying their Antibacterial Activity

Mixed ligands of 2-benzoyl Thiobenzimiazole (L1) with 1,10-phenanthroline (L2) complexes of Cr(III) , Ni(II) and Cu(II) ions were prepared. The ligand and the complexes were isolated and characterized in solid state by using FT-IR, UV-Vis spectroscopy, 1H, 13C-NMR, flame atomic absorption, elemental micro analysis C.H.N.S, magnetic susceptibility , melting points and conductivity measurements. 2-Benzoyl thiobenzimiazole behaves as bidenetate through oxygen atom of carbonyl group and nitrogen atom of imine group. From the analyses Octahedral geometry was suggested for all prepared complexes. A theoretical treatment of ligands and their metal complexes in gas phase were studied using HyperChem-8 program, moreover, ligands in gas phase also has been studied using Gaussian program (GaussView Currently Available Version (5.0.9) along with Gaussian 09 which was the latest in the Gaussian series of programs). The antibacterial activity of the prepared complexes have been determined and compared with that of the ligand and the standard metronidazole

Tourism Companies Assessment via Social Media Using Sentiment Analysis

ازدادت وسائل التواصل الاجتماعي بشكل كبير وواضح لانها وسيلة إعلام للمستخدمين للتعبير عن مشاعرهم من خلال آلاف المنشورات والتعليقات حول شركات السياحة. وبالتالي ، يصعب على السائح قراءة جميع التعليقات لتحديد ما إذا كانت تلك الآراء إيجابية أم سلبية لتقييم نجاح الشركة. في هذه البحث,تم استخدام التنقيب عن النص لتصنيف المشاعر من خلال جمع مراجعات اللهجة العراقية حول شركات السياحة من الفيس بوك لتحليلها باستخدام تحليل المشاعر لتتبع المشاعر الموجوده في المنشورات والتعليقات. ثم تم تصنيفها إلى تعليق إيجابي أو سلبي أو محايد باستخدام Naïve Bayes, Rough Set Theory , K-Nearest Neighbor. من بين 71 شركة سياحة عراقية وجدت أن 28٪ من هذه الشركات لديها تقييم جيد جدا ، و 26٪ من هذه الشركات لديها تقييم جيد ، و 31٪ من هذه الشركات لديها تقييم متوسط ​​، و 4٪ من هذه الشركات لديها تقييم مقبول و 11٪ من هذه الشركات لديها تقييم سيء. ساعدت النتائج التجريبية الشركات على تحسين عملها وبرامجها واستجابة كافية وسريعة لمتطلبات العملاءIn recent years, social media has been increasing widely and obviously as a media for users expressing their emotions and feelings through thousands of posts and comments related to tourism companies. As a consequence, it became difficult for tourists to read all the comments to determine whether these opinions are positive or negative to assess the success of a tourism company. In this paper, a modest model is proposed to assess e-tourism companies using Iraqi dialect reviews collected from Facebook. The reviews are analyzed using text mining techniques for sentiment classification. The generated sentiment words are classified into positive, negative and neutral comments by utilizing Rough Set Theory, Naïve Bayes and K-Nearest Neighbor methods. After experimental results, it was determined that out of 71 tested Iraqi tourism companies, 28% from these companies have very good assessment, 26% from these companies have good assessment, 31% from these companies have medium assessment, 4% from these companies have acceptance assessment and 11% from these companies have bad assessment. These results helped the companies to improve their work and programs responding sufficiently and quickly to customer demands