119 research outputs found

    Development and Validation of the Inviting Teaching Effectiveness Scale based on the Invitational Theory

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    This study reports on a new instrument, the Inviting Teaching Effectiveness Scale (ITES), which is a 20-item measure based on the fundamental teaching competencies derived from the principles of Invitational Education (Purkey & Novak, 1984). The initial instrument had included 30 items and was then validated on a random sample of 640 students enrolled at the University of Bahrain. The final version of the developed Scale contains 20 items and measures four aspects of inviting teaching effectiveness: Invitational instruction, inviting relationships, invitational assessment and inviting classroom environment. As the new Scale displayed sound psychometric properties, it can be considered as a potentially useful tool to assess teacher performance and improve teaching practices at tertiary level of education. Information about test construction, reliability, validity, and generalizability are presented and implications and benefits associated with use of the instrument as a tool for measuring teaching effectiveness are discussed

    Using Item Response Models to Develop a Criterion-Referenced Test to Measure the Students' Achievement in Educational Evaluation

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    The purpose of the study was to develop a criterion-referenced test to measure student's achievement in educational evaluation using item response theory. To achieve this goal, the author constructed a 3-option multiple-choice achievement test of 48 items that was later administered to 348 students enrolled at the University of Bahrain. The findings of study revealed that the students' responses to 31 items fit the Rasch model assumptions while 17 items did not fit the model. All items of the final version of the test, however, were located within the range of the model's infit and outfit indicators. Also, the reliability estimates for persons and items were .87 and .93, respectively, indicating a high reliability of the test, and the maximum information extracted from the three-option test is obtained at the average ability levels. Based on these results, the author recommends using the developed test as a reliable measure of the level of university student's achievement in the subject of educational evaluatio

    Development of a convolutional neural network joint detector for non-orthogonal multiple access uplink receivers

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    We present a novel approach to signal detection for Non-Orthogonal Multiple Access (NOMA) uplink receivers using Convolutional Neural Networks (CNNs) in a single-shot fashion. The defacto NOMA detection method is the so-called Successive Interference Cancellation which requires precise channel estimation and accurate successive detection of the user equipment with the higher powers. It is proposed converting incoming packets into 2D image-like streams. These images are fed to a CNN-based deep learning network commonly used in the image processing literature for image classification. The classification label for each packet converted to an image is the transmitted symbols by all user equipment joined together. CNN network is trained using uniformly distributed samples of incoming packets at different signals to noise ratios. Furthermore, let’s performed hyperparameter optimization using the exhaustive search method. Our approach is tested using a modeled system of two user equipment systems in a 64-subcarrier Orthogonal Frequency Division Multiplexing (OFDM) and Rayleigh channel. It is found that a three-layer CNN with 32 filters of size 7Ă—7 has registered the highest training and testing accuracy of about 81. In addition, our result showed significant improvement in Symbol Error Rate (SER) vs. Signal to Noise Ratio (SNR) compared to other state-of-the-art approaches such as least square, minimum mean square error, and maximum likelihood under various channel conditions. When the channel length is fixed at 20, our approach is at least one significant Figure better than the maximum likelihood method at (SNR) of 2 dB. Finally, the channel length to 12 is varied and it is registered about the same performance. Hence, our approach is more robust to joint detection in NOMA receivers, particularly in low signal-to-noise environment

    Insight into mechanics of AFM tip-based nanomachining: bending of cantilevers and machined grooves

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    Atomic force microscope (AFM) tip-based nanomachining is currently the object of intense research investigations. Values of the load applied to the tip at the free end of the AFM cantilever probe used for nanomachining are always large enough to induce plastic deformation on the specimen surface contrary to the small load values used for the conventional contact mode AFM imaging. This study describes an important phenomenon specific for AFM nanomachining in the forward direction: under certain processing conditions, the deformed shape of the cantilever probe may change from a convex to a concave orientation. The phenomenon can principally change the depth and width of grooves machined, e.g. the grooves machined on a single crystal copper specimen may increase by 50% on average following such a change in the deformed shape of the cantilever. It is argued that this phenomenon can take place even when the AFM-based tool is operated in the so-called force-controlled mode. The study involves the refined theoretical analysis of cantilever probe bending, the analysis of experimental signals monitored during the backward and forward AFM tip-based machining and the inspection of the topography of produced grooves

    Real-Time classification of various types of falls and activities of daily livings based on CNN LSTM network

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    In this research, two multiclass models have been developed and implemented, namely, a standard long-short-term memory (LSTM) model and a Convolutional neural network (CNN) combined with LSTM (CNN-LSTM) model. Both models operate on raw acceleration data stored in the Sisfall public dataset. These models have been trained using the TensorFlow framework to classify and recognize among ten different events: five separate falls and five activities of daily livings (ADLs). An accuracy of more than 96% has been reached in the first 200 epochs of the training process. Furthermore, a real-time prototype for recognizing falls and ADLs has been implemented and developed using the TensorFlow lite framework and Raspberry PI, which resulted in an acceptable performance

    Comparison between torsional spring constants of rectangular and V-shaped AFM cantilevers

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    The properties of force-sensing micro-cantilevers are of fundamental importance for measurements employing atomic force microscopy (AFM) techniques. Due to the well-known arguments of Sader, it is generally accepted that V-shaped cantilevers are more sensitive to lateral forces than rectangular ones. We present results of numerical (finite element modelling) and experimental comparison between torsional spring constants of rectangular and V-shaped commercial AFM cantilevers. As representative example of such beams, we considered AFM probes available commercially. In particular, we tested scaled-up models of V-shaped cantilevers which had the same geometrical shapes as commercial AFM cantilevers. Both the rectangular and the Vshaped larger scale models were made of the same material; they had the same length, thickness, normal spring constant, as well as the same location and shape of the tip base. In the experiments and the simulations, an external lateral load was applied to the free end of the tip. A good agreement between the experimental work and finite element method (FEM) simulations was observed. The results show that the torsional spring constant of the V-shape cantilevers considered here was greater than that of the equivalent rectangular beams by up to 45%. The discrepancy with the results from Sader should be caused by differences in both the load transfer scheme and the geometrical shapes of the V-shaped beams

    Evaluation of Streptocin SH3, a Bacteriocin produced by Streptococcus sanguinis isolated from Human Dental Plaque

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    Background: Bacteriocin is a peptidic toxin has many advantages to bacteria in their ecological niche and has strong antibacterial activity. Objective: The aim of this study was to evaluation of bacteriocin using Streptococcus sanguinis isolated from human dental caries. Subjects and Methods: Thirty five streptococcus isolates were diagnosed and tested for their production of bacteriocin, and then the optimal conditions for production of bacteriocin were determined.  After that, the purification of bacteriocin was made partially by ammonium sulfate at 95% saturation levels, followed by and gel filtration chromatography using Sephadex G-50 column. Finally, physical characteristics were also studied and determined the bacteriocin stability. Results: Among all streptococcal isolates, the S. sanguinis SH3 isolate with batter antimicrobial activity was selected, and used in further experiments. The optimum conditions for bacteriocin production were in Todd Hewitt broth (THB) supplemented with 1% glucose at 37°C for 24h under anaerobic conditions and inoculum size of (1.2 ˟ 109CFU/ml) and pH 7, where the inhibition zone diameter reached to 29 mm against Enterococcus faecalis. The purified bacteriocin had high inhibitory activity against S. pneumoniae, S. pyogenes, E. faecalis, E. faecium and  Leuconostoc mesenteroides. Streptocin SH3 keeps its effectiveness within the pH range 3-10, and temperature until 80ºC for 20 min. Conclusion: Bacteriocin produced from S. sanguinis has high activity against many pathogens and has high stability over wide ranges of temperature and pH, which makes it a good alternative in the medical and food preservation field

    Using Multiplex PCR Assay for Detection of Genital Mycoplasmasand Ureaplasmaspp in an Infertility Males.

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    ABSTACTThe result of the multiplex-PCR revealed positive results in 13(15.1%) of the 86 seminal fluid samples from infertile patients which represented M.hominis 5(5.8%), U.urealyticum in 5(5.8%) and U.parvum3(3.5%).Conclusion: in light of the results obtained this study we concludes that the efficiency of multiplex-PCR large and rapid in diagnosis of Ureaplasmaspp and Mycoplasma hominis in seminal fluid.Recommendation : the study of detection of other microorganism (viruses, fungi, Chlamydia and Neisseria gonorrhea) in men infertility.Key words: Multiplex-PCR,Mycoplasma, Ureaplasma,Men, Infertility

    Bacterial Contamination of Imported and Local Corn Kernel (Used as Animal Feed) in Iraq

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    This study was carried out to determine bacterial contamination of imported and local corn kernel (used as animal feed) in Iraq, which causes diseases and great economic losses. A total of 163 samples were collected (100 samples of the imported corn kernel from border points and 63 samples of the local corn kernel from the provinces) and cultured then Isolates were identified according to morphological Characteristics, biochemical tests and Agglutination test. The results indicated a total Gram-negative bacteria in 94 samples of the total samples (163) at (58%), includes: 57 Isolates from the imported corn kernel at (57%), which includes :Salmonella spp. in 14 samples at (14%), Escherichia coli in 21 samples at (21%), Klebsiella spp. in 13 samples at (13%), Proteus spp. in 9 samples at (9%) but absence of Serratia spp. and Enterobacter spp. . Addition to 37 Isolates from the local corn kernel at (60%),which includes: Salmonella spp. in 10 samples at (16%), Escherichia coli in 15 samples at (24%), Proteus spp. in 6 samples at (10%), Serratia spp. in 3 samples at (5%), Enterobacter spp. in 3 samples at (5%) but absence of Klebsiella spp. This study concluded that must be evaluated the microbial quality of imported and local corn kernel (used as animal feed) by manufacturers and health authorities to ensure safety and quality of corn to prevent diseases and great economic losses

    Bacterial Contamination of Imported and Local Corn Kernel (Used as Animal Feed) in Iraq

    Get PDF
    This study was carried out to determine bacterial contamination of imported and local corn kernel (used as animal feed) in Iraq, which causes diseases and great economic losses. A total of 163 samples were collected (100 samples of the imported corn kernel from border points and 63 samples of the local corn kernel from the provinces) and cultured then Isolates were identified according to morphological Characteristics, biochemical tests and Agglutination test. The results indicated a total Gram-negative bacteria in 94 samples of the total samples (163) at (58%), includes: 57 Isolates from the imported corn kernel at (57%), which includes :Salmonella spp. in 14 samples at (14%), Escherichia coli in 21 samples at (21%), Klebsiella spp. in 13 samples at (13%), Proteus spp. in 9 samples at (9%) but absence of Serratia spp. and Enterobacter spp. . Addition to 37 Isolates from the local corn kernel at (60%),which includes: Salmonella spp. in 10 samples at (16%), Escherichia coli in 15 samples at (24%), Proteus spp. in 6 samples at (10%), Serratia spp. in 3 samples at (5%), Enterobacter spp. in 3 samples at (5%) but absence of Klebsiella spp. This study concluded that must be evaluated the microbial quality of imported and local corn kernel (used as animal feed) by manufacturers and health authorities to ensure safety and quality of corn to prevent diseases and great economic losses
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