Proposing a model for evaluation of effective electronic learning strategies on students' achievement: A case study in virtual universities

The aim of the present study was to evaluate the effective electronic learning strategies on virtual students' academic improvement. The research method of the present study is correlational-descriptive. The population of the study includes all the virtual universities' students of Iran in academic year of 2011-2012. According to Morgan's Table, finally 363 participants were selected for the study. There are three data collection instruments including: a researcher-made questionnaire about electronic learning strategies (α=.94), a researcher-made questionnaire of educational interest (α=.92), and a comparison of students' mean scores during two successive terms in achievement tests (tests of the taken courses). Validity of the mentioned questionnaires was provided in terms of content. The results of the study indicated that there has been a significant relationship between electronic learning strategies based on cognitive presence, social presence, and teaching presence with virtual students' achievements

Proposing a model for evaluation of effective electronic learning strategies on students' achievement: A case study in virtual universities

The aim of the present study was to evaluate the effective electronic learning strategies on virtual students' academic improvement. The research method of the present study is correlational-descriptive. The population of the study includes all the virtual universities' students of Iran in academic year of 2011-2012. According to Morgan's Table, finally 363 participants were selected for the study. There are three data collection instruments including: a researcher-made questionnaire about electronic learning strategies (α=.94), a researcher-made questionnaire of educational interest (α=.92), and a comparison of students' mean scores during two successive terms in achievement tests (tests of the taken courses). Validity of the mentioned questionnaires was provided in terms of content. The results of the study indicated that there has been a significant relationship between electronic learning strategies based on cognitive presence, social presence, and teaching presence with virtual students' achievements

Innate and discretionary accruals quality and corporate governance: A case study of Tehran Stock Exchange

In this paper, we present an empirical study to find the relationship between discretionary accruals quality as well as innate accruals quality and portion of non-executive board of directors, concentration of ownership ratio and board size in Tehran Stock Exchange. The survey selects 118 qualified stocks from this exchange and using a random technique chooses 42 firms. The study implements two linear regression techniques to estimate the first part of the information and then using structural equation modeling examines six hypotheses. Based on the results of this survey we can conclude that an increase on non-executive members positively influences on discretionary accruals quality and negatively influences innate accruals quality. Concentration of ownership ratio positively influences on discretionary accruals quality and negatively impacts on innate accruals quality. Finally, size of board of directors negatively impacts discretionary accruals quality and positively influences on innate accruals quality

Measuring relative performance of banking industry using a DEA and TOPSIS

One of the primary concerns in banking industry is to measure the relative importance of banking industry using popular multi criteria decision making (MCDM) techniques such as data envelopment analysis (DEA) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). In this paper, we use these two MCDM techniques to measure the relative efficiencies of 16 private and governmental banks in terms of electronic payment. There are three inputs with DEA methods including the number of issued cards, the number of ATM machines and the number of POSs and there are two outputs including the number of successful ATMs and the number of successful POSs transactions. The proposed study of this paper uses the necessary data of one of Iranian provinces and the results of the implementation of DEA and TOPSIS have indicated that 9 out of 16 banks were efficient. Our study also indicates that mean of relative efficiency for private banks was 82% while this number was 75% for governmental banks

Loss-Modified Transformer-Based U-Net for Accurate Segmentation of Fluids in Optical Coherence Tomography Images of Retinal Diseases.

Optical coherence tomography (OCT) imaging significantly contributes to ophthalmology in the diagnosis of retinal disorders such as age-related macular degeneration and diabetic macular edema. Both diseases involve the abnormal accumulation of fluids, location, and volume, which is vitally informative in detecting the severity of the diseases. Automated and accurate fluid segmentation in OCT images could potentially improve the current clinical diagnosis. This becomes more important by considering the limitations of manual fluid segmentation as a time-consuming and subjective to error method. Deep learning techniques have been applied to various image processing tasks, and their performance has already been explored in the segmentation of fluids in OCTs. This article suggests a novel automated deep learning method utilizing the U-Net structure as the basis. The modifications consist of the application of transformers in the encoder path of the U-Net with the purpose of more concentrated feature extraction. Furthermore, a custom loss function is empirically tailored to efficiently incorporate proper loss functions to deal with the imbalance and noisy images. A weighted combination of Dice loss, focal Tversky loss, and weighted binary cross-entropy is employed. Different metrics are calculated. The results show high accuracy (Dice coefficient of 95.52) and robustness of the proposed method in comparison to different methods after adding extra noise to the images (Dice coefficient of 92.79). The segmentation of fluid regions in retinal OCT images is critical because it assists clinicians in diagnosing macular edema and executing therapeutic operations more quickly. This study suggests a deep learning framework and novel loss function for automated fluid segmentation of retinal OCT images with excellent accuracy and rapid convergence result. [Abstract copyright: Copyright: © 2023 Journal of Medical Signals & Sensors.

Dual-Tree Complex Wavelet Input Transform for Cyst Segmentation in OCT Images Based on a Deep Learning Framework

Optical coherence tomography (OCT) represents a non-invasive, high-resolution cross-sectional imaging modality. Macular edema is the swelling of the macular region. Segmentation of fluid or cyst regions in OCT images is essential, to provide useful information for clinicians and prevent visual impairment. However, manual segmentation of fluid regions is a time-consuming and subjective procedure. Traditional and off-the-shelf deep learning methods fail to extract the exact location of the boundaries under complicated conditions, such as with high noise levels and blurred edges. Therefore, developing a tailored automatic image segmentation method that exhibits good numerical and visual performance is essential for clinical application. The dual-tree complex wavelet transform (DTCWT) can extract rich information from different orientations of image boundaries and extract details that improve OCT fluid semantic segmentation results in difficult conditions. This paper presents a comparative study of using DTCWT subbands in the segmentation of fluids. To the best of our knowledge, no previous studies have focused on the various combinations of wavelet transforms and the role of each subband in OCT cyst segmentation. In this paper, we propose a semantic segmentation composite architecture based on a novel U-net and information from DTCWT subbands. We compare different combination schemes, to take advantage of hidden information in the subbands, and demonstrate the performance of the methods under original and noise-added conditions. Dice score, Jaccard index, and qualitative results are used to assess the performance of the subbands. The combination of subbands yielded high Dice and Jaccard values, outperforming the other methods, especially in the presence of a high level of noise

The Principle of Dominance and the Limitation of Changing the Use of Agricultural and Garden Lands

The purpose of the present study was to investigate the principle of dominance and limitations imposed on changing the use of agricultural and garden lands. The former and latter are considered as important subjects continuously debated and discussed. Changing the use of garden and agricultural lands is a theoretically argued subject and is followed by the principal question of: how in the face of the dominance principle, the legal limitations in changing the use of agricultural and garden lands are justifiable? In terms of the method of study.the present research falls into the category of descriptive-analytic researches, and library studies have been conducted to answer the mentioned question. The results of the present study indicate that illegal change of use of agricultural lands is an obvious instance of conflict between personal and societal rights. Because the owner of an agricultural land, due to his/her personal rights is allowed to use the land in any legitimate and legal way he/she desires; however, the rights of the society and the future humans forbids the owner to use the land in ways that would harm the public/society. Based on the stated content, it is concluded that the ownership right is absolutely preserved for the real owner based on the principle of dominance, but in cases where this right is conflictual with societal rights, the societal rights would be counted prioritized over the former, and therefore it would be necessary to control personal rights. This preference has a clear and obvious instance in the context of changing the use of agricultural and garden lands; and it is rational that the society’s right will be dominant over the rights of the owner of agricultural and garden lands

The effect of mesenchymal stem cells as co-culture in in vitro nuclear maturation of ovine oocytes

This study compared the effects of ovine mesenchymal stem cells (MSCs) and ovine oviductal epithelial cells (OECs) as feeder cells in cell free culture systems (HEPES-modified tissue culture medium, TCM199) supplemented with polyvinyl alcohol (PVA) or fetal calf serum (FCS) on in vitro oocyte maturation and subsequent embryo development (IVM/IVC). Cumulus-oocyte complexes (COCs) were harvested from ovine ovaries and subjected to IVM in the above-mentioned culture media. After culture for 24 h, nuclear maturation of the oocytes was evaluated by 4, 6-diamino- 2-phenylindole (DAPI) staining. After fertilization the presumptive zygotes were cultured under identical culture conditions and embryo development was evaluated. The percentage of oocytes at nuclear maturation (metaphase II) cultured in the MSC group was higher than for the IVM medium + PVA group (P<0.05), while between MSCs, OECs and IVM medium + FCS it was non-significant. The rates (%) of cleavage and the percentage of total blastocysts in MSCs and the IVM medium + FCS group were higher than for OECs and the IVM medium + PVA group (P<0.05). These rates were non-significant between MSCs and the IVM medium + FCS group or between OECs and the IVM medium + PVA group. The percentage of hatched blastocysts (%) was significantly increased in MSCs and the IVM medium + FCS group when compared to OECs and the IVM medium + PVA group (P<0.05). In conclusion, the effects of mesenchymal stem cells as co-culture on oocyte maturation and the successive embryo development in vitro are similar to those in the medium supplemented with FCS. This study suggests that co-culturing with mesenchymal stem cells may be a promising alternative to FCS-medium