New Adaptive Data Transmission Scheme Over HF Radio

Acceptable Bit Error rate can be maintained by adapting some of the design parameters such as modulation, symbol rate, constellation size, and transmit power according to the channel state.<br />An estimate of HF propagation effects can be used to design an adaptive data transmission system over HF link. The proposed system combines the well known Automatic Link Establishment (ALE) together with variable rate transmission system. The standard ALE is modified to suite the required goal of selecting the best carrier frequency (channel) for a given transmission. This is based on measuring SINAD (Signal plus Noise plus Distortion to Noise plus Distortion), RSL (Received Signal Level), multipath phase distortion and BER (Bit Error Rate) for each channel in the frequency list. Channel condition evaluation is done by two arrangements. In the first an FFT analysis is used where a pilot signal is transmitted over the channel, while the data itself is used in the second arrangement. Passive channel assessment is used to avoid bad channels hence limiting the frequency pool size to be used in the point to point communication and the time required for scanning and linking. An exchange of channel information between the transmitting and receiving stations is considered to select the modulation scheme for transmission. Mainly MPSK and MFSK are considered with different levels giving different data rate according to the channel condition. The results of the computer simulation have shown that when transmitting at a fixed channel symbol rate of 1200 symbol/sec, the information rate ranges from 2400 bps using 4FSK up to 3600 bps using 8PSK for SNR ranges from 11dB up to 26dB.<br /

Adsorption of acid orange 7 by cetylpyridinium bromide modified sugarcane bagasse

In the present study, the adsorption of acid orange 7 (AO7) dye from aqueous solution by sugarcane bagasse (SB) and cetylpyridinium bromide (CPBr) modified sugarcane bagasse (SBC) was examined. SBC was prepared by reacting SB with different concentrations (0.1, 1.0 and 4.0 mM) of cationic surfactant, CPBr. The SB and SBC were characterized using Fourier transform infrared (FTIR) spectroscopy. The adsorption experiments were carried out in a batch mode. The effect of initial AO7 concentrations (5-1000 mg/L), initial CPBr concentrations and pH of AO7 solution (2-9) on the adsorption capacity of SB and SBC were investigated. The experimental adsorption data were analyzed using Langmuir and Freundlich isotherm models. The adsorption of AO7 onto SB and SBC followed Freundlich and Langmuir isotherm models, respectively. The maximum uptake of AO7 was obtained by SBC4.0 (SB treated with 4.0 mMCPBr) with the adsorption capacity of 144.928 mg/g. The highest AO7 removal was found to be at pH 2 and 7 for SB and SBC, respectively. As a conclusion, sugarcane bagasse modified with CPBr can become an alternative adsorbent for the removal of anionic compounds in aqueous solution

The School Principal Role in Motivating Second Cycle Teachers In AI Ain City.

This study aims to identify the role of school principals in motivating teachers in the second cycle schools in Al Ain City, through answering the following research questions: To what extent do school principals in Al Ain City schools assume the role of teacher motivation from the viewpoint of second cycle teachers in Al Ain schools? And what are the teachers\u27 proposals for activating the role of school principals in teacher recommendations/suggestions? A mixed (quantitative - qualitative) approach was used, which adopted a questionnaire and open questions. The research sample included 258 teachers in 4 boy schools in the second cycle in Al Ain. The study revealed that the motivational practices of school principals in the moral, administrative and social aspects, ranged from average to weak while financial motivation was very weak. Moreover, teachers stressed the need for enhancing all forms of motivation through making motivation methods such as professional development programs for school principals, giving school principals more powers and independence, and good vocational and educational choice of school principals who are able to invest the potential of teachers and motivate them

Towards designing a high intelligibility rule based standard malay text-to-speech synthesis system

Although text-to-speech (TTS) technology has gained some interest from amateur and professional researchers in developing a Standard Malay (SM) text- to- speech synthesizer, however, up to this day, there is rarely any high intelligible TTS system which is freely accessible to be implemented and introduced to the community of SM speakers. Therefore, identification of the core components required for the development of SM TTS system especially in establishing the NLP module should be carried out intensively. This paper presents a rule-based text- to- speech synthesis system for Standard Malay, named SMaTTS. An intelligible and adequately natural sounding formant-based speech synthesis system with a light and user-friendly Graphical User Interface (GUI) was developed. Result and suggestion for future improvements is discussed. The available Malay TTS synthesizers, the algorithms and speech engine in used, as well as their strong and weak points for each of the system are discussed in this paper. Assessment was made at all possible levels; phoneme, word and sentence level. The overall performance of the system is analyzed using Categorical Estimation (CE) for a comprehensive analysis. Result and suggestion for future improvements is discussed

SCAFFOLDINGAND REINFORCEMENT: USING DIGITAL LOGBOOKS IN LEARNING VOCABULARY

Reinforcement and scaffolding are tested approaches to enhance learning achievements. Keeping a record of the learning process as well as the new learned words functions as scaffolding to help learners build a comprehensive vocabulary. Similarly, repetitive learning of new words reinforces permanent learning for long-term memory. Paper-based logbooks may prove to be good records of the learning process, but if learners use digital logbooks, the results may be even better. Digital logbooks with an extended page with hyperlinked information on word-knowledge may work both ways – as scaffolding to learning as well as reinforcement to the learning process. In the present paper the researcher has suggested for the development of a software called ‘Vocabulary log book,’ which combines the features of Microsoft Word, online dictionary and online grammar books, so that the information needed by learners of a foreign language to learn its lexicon is available on a single page. The researcher believes that such a page will help learners master the new words quickly and efficiently

SMaTTS: standard malay text to speech system

This paper presents a rule-based text- to- speech (TTS) Synthesis System for Standard Malay, namely SMaTTS. The proposed system using sinusoidal method and some pre- recorded wave files in generating speech for the system. The use of phone database significantly decreases the amount of computer memory space used, thus making the system very light and embeddable. The overall system was comprised of two phases the Natural Language Processing (NLP) that consisted of the high-level processing of text analysis, phonetic analysis, text normalization and morphophonemic module. The module was designed specially for SM to overcome few problems in defining the rules for SM orthography system before it can be passed to the DSP module. The second phase is the Digital Signal Processing (DSP) which operated on the low-level process of the speech waveform generation. A developed an intelligible and adequately natural sounding formant-based speech synthesis system with a light and user-friendly Graphical User Interface (GUI) is introduced. A Standard Malay Language (SM) phoneme set and an inclusive set of phone database have been constructed carefully for this phone-based speech synthesizer. By applying the generative phonology, a comprehensive letter-to-sound (LTS) rules and a pronunciation lexicon have been invented for SMaTTS. As for the evaluation tests, a set of Diagnostic Rhyme Test (DRT) word list was compiled and several experiments have been performed to evaluate the quality of the synthesized speech by analyzing the Mean Opinion Score (MOS) obtained. The overall performance of the system as well as the room for improvements was thoroughly discussed

Synthesis, structural and optical properties of ZnO Nano-rods used in Solar Cells fabrication

Sudan has vast areas of fertile land, abundance of minerals, water, winds and sunshine, many types of these energies become a valid option. However, in this research, the focus shall only be concern-ing one type of renewable energy, which is solar energy. The conventional solar cells are mainly made up of doped silicon electrodes. Their major task is to convert visible light to electrical energy according to the photovoltaic (PV) conversion method. However the production of these crystalline silicon solar cells is very complicated and expensive. Therefore the aim of this research is to produce ZnO nano-rods with optimum characteristics that can be used in the construction of low-cost solar cells. Zinc Oxide (ZnO) nano-rods in powder form were synthesized using the hydrothermal method, which is a simple and inex-pensive method. The refinement of X-Ray diffraction (XRD) pattern was used to find and investigate the structural properties of the nano-rods. The morphology and size of the ZnO nano-rods were determined by a Transmission Electron Microscope (TEM), while the EDX studies confirmed the formation of ZnO functional group. The optical band gap energy was obtained using both UV-VIS-NIR diffuse reflectance and absortion spectroscopy also photo-luminesces (PL) was used

English digits speech recognition system based on hidden Markov Models

The field of Automatic Speech Recognition (ASR) is about 60 years old. There have been many interesting advances and developments since the invention of the first speech recognizer at Bell Labs in the early 1950' s. The development of ASR increased gradually until the invention of Hidden Markov Models (HMM) in early 1970's. Researchers' contribution were to make use of ASR technology to what can be seen nowadays of various advancements in fields like multi-modal, multi-linguaVcross-lingual ASR using statistical techniques such as HMM, SVM, neural network, etc [1]