53 research outputs found

    A Target Sequential Effect on the Forced-Choice Prime Visibility Test in Unconscious Priming Studies: A Caveat for Researchers

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    In unconscious priming studies, most researchers adopt a combination of subjective and objective measures to assess the visibility of the prime. Although some carry out the visibility test at the end of the experiment separately from the unconscious priming task, others suggest that the forced-choice visibility test should be conducted immediately after the response to the target within each trial. In the present study, the influence of prime and target on the forced-choice prime discrimination was assessed within each trial. The results showed that the target affected the response in the forced-choice prime visibility test. Participants tended to make the same response or avoid repeating the same response they made to the target as in Experiments 1 and 3 rather than randomly guessing. However, even when the forcedchoice visibility test was conducted separately from the priming experiment, the problem was not completely solved, because some participants tended to make one same response in the forced-choice visibility test as in Experiments 2. From another point of view, using these strategies in the forced-choice task can be seen as a helpless move by the participants when they are unaware of the stimuli. Furthermore, the results revealed that the forced-choice test performed immediately after the response to the target within each trial could possibly impair the unconscious priming as well as produce misleading visibility test results. Therefore, it is suggested that the forced-choice prime visibility test and the unconscious priming task may better be conducted separately

    Power Allocation Strategy of Maximizing Secrecy Rate for Secure Directional Modulation Networks

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    In this paper, given the beamforming vector of confidential messages and artificial noise (AN) projection matrix and total power constraint, a power allocation (PA) strategy of maximizing secrecy rate (Max-SR) is proposed for secure directional modulation (DM) networks. By the method of Lagrange multiplier, the analytic expression of the proposed PA strategy is derived. To confirm the benefit from the Max-SRbased PA strategy, we take the null-space projection (NSP) beamforming scheme as an example and derive its closed-form expression of optimal PA strategy. From simulation results, we find the following facts: in the medium and high signal-to-noiseratio (SNR) regions, compared with three typical PA parameters such ? = 0:1, 0:5, and 0:9, the optimal PA shows a substantial SR performance gain with maximum gain percent up to more than 60%. Additionally, as the PA factor increases from 0 to 1, the achievable SR increases accordingly in the low SNR region whereas it first increases and then decreases in the medium and high SNR regions, where the SR can be approximately viewed as a convex function of the PA factor. Finally, as the number of antennas increases, the optimal PA factor becomes large and tends to one in the medium and high SNR region. In other words, the contribution of AN to SR can be trivial in such a situation

    GPI-Based Secrecy Rate Maximization Beamforming Scheme for Wireless Transmission With AN-Aided Directional Modulation

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    In a directional modulation network, a general power iterative (GPI) based beamforming scheme is proposed to maximize the secrecy rate (SR), where there are two optimization variables required to be optimized. The ?rst one is the useful precoding vector of transmitting con?dential messages to the desired user while the second one is the arti?cial noise (AN) projection matrix of forcing more AN to eavesdroppers. In such a secure network, the paramount problem is how to design or optimize the two optimization variables by different criteria. To maximize the SR (Max-SR), an alternatively iterative structure (AIS) is established between the AN projection matrix and the precoding vector for con?dential messages. To choose a good initial value of iteration process of GPI, the proposed Max-SR method can readily double its convergence speed compared to the random choice of initial value. With only four iterations, it may rapidly converge to its rate ceil. From simulation results, it follows that the SR performance of the proposed AIS of GPI-based Max-SR is much better than those of conventional leakage-based and null-space projection methods in the medium and large signal-to-noise ratio (SNR) regions, and its achievable SR performance gain gradually increases as SNR increases

    Problematic Internet use (PIU) in youth: A brief literature review of selected topics

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    We aimed to discuss several selected topics related to problematic Internet use (PIU), including fear of missing out, nomophobia, cyberchondria, cyberbullying, and certain health conditions (e.g. autism-spectrum disorder and schizophrenia) among youth. We also aimed to review some recent evidence examining PIU during COVID-19. The review was conducted using keywords relevant to the selected topics and searching in the PubMed database and Google Scholar. The results of this review indicate that PIU could be associated with health issues in a minority of the youth population. Moreover, the COVID-19 pandemic may lead to PIU and subsequent health problems. Information from this review could help healthcare providers to design individualized and appropriate interventions to tackle health issues related to PIU among youth

    Genetic variants associated with fasting glucose and insulin concentrations in an ethnically diverse population: results from the Population Architecture using Genomics and Epidemiology (PAGE) study

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    Background: Multiple genome-wide association studies (GWAS) within European populations have implicated common genetic variants associated with insulin and glucose concentrations. In contrast, few studies have been conducted within minority groups, which carry the highest burden of impaired glucose homeostasis and type 2 diabetes in the U.S. Methods: As part of the 'Population Architecture using Genomics and Epidemiology (PAGE) Consortium, we investigated the association of up to 10 GWAS-identified single nucleotide polymorphisms (SNPs) in 8 genetic regions with glucose or insulin concentrations in up to 36,579 non-diabetic subjects including 23,323 European Americans (EA) and 7,526 African Americans (AA), 3,140 Hispanics, 1,779 American Indians (AI), and 811 Asians. We estimated the association between each SNP and fasting glucose or log-transformed fasting insulin, followed by meta-analysis to combine results across PAGE sites. Results: Overall, our results show that 9/9 GWAS SNPs are associated with glucose in EA (p = 0.04 to 9 × 10-15), versus 3/9 in AA (p= 0.03 to 6 × 10-5), 3/4 SNPs in Hispanics, 2/4 SNPs in AI, and 1/2 SNPs in Asians. For insulin we observed a significant association with rs780094/GCKR in EA, Hispanics and AI only. Conclusions: Generalization of results across multiple racial/ethnic groups helps confirm the relevance of some of these loci for glucose and insulin metabolism. Lack of association in non-EA groups may be due to insufficient power, or to unique patterns of linkage disequilibrium

    Evaluation of a computer-aided diagnostic model for corneal diseases by analyzing in vivo confocal microscopy images

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    ObjectiveIn order to automatically and rapidly recognize the layers of corneal images using in vivo confocal microscopy (IVCM) and classify them into normal and abnormal images, a computer-aided diagnostic model was developed and tested based on deep learning to reduce physicians’ workload.MethodsA total of 19,612 corneal images were retrospectively collected from 423 patients who underwent IVCM between January 2021 and August 2022 from Renmin Hospital of Wuhan University (Wuhan, China) and Zhongnan Hospital of Wuhan University (Wuhan, China). Images were then reviewed and categorized by three corneal specialists before training and testing the models, including the layer recognition model (epithelium, bowman’s membrane, stroma, and endothelium) and diagnostic model, to identify the layers of corneal images and distinguish normal images from abnormal images. Totally, 580 database-independent IVCM images were used in a human-machine competition to assess the speed and accuracy of image recognition by 4 ophthalmologists and artificial intelligence (AI). To evaluate the efficacy of the model, 8 trainees were employed to recognize these 580 images both with and without model assistance, and the results of the two evaluations were analyzed to explore the effects of model assistance.ResultsThe accuracy of the model reached 0.914, 0.957, 0.967, and 0.950 for the recognition of 4 layers of epithelium, bowman’s membrane, stroma, and endothelium in the internal test dataset, respectively, and it was 0.961, 0.932, 0.945, and 0.959 for the recognition of normal/abnormal images at each layer, respectively. In the external test dataset, the accuracy of the recognition of corneal layers was 0.960, 0.965, 0.966, and 0.964, respectively, and the accuracy of normal/abnormal image recognition was 0.983, 0.972, 0.940, and 0.982, respectively. In the human-machine competition, the model achieved an accuracy of 0.929, which was similar to that of specialists and higher than that of senior physicians, and the recognition speed was 237 times faster than that of specialists. With model assistance, the accuracy of trainees increased from 0.712 to 0.886.ConclusionA computer-aided diagnostic model was developed for IVCM images based on deep learning, which rapidly recognized the layers of corneal images and classified them as normal and abnormal. This model can increase the efficacy of clinical diagnosis and assist physicians in training and learning for clinical purposes

    The 5th International Conference on Biomedical Engineering and Biotechnology (ICBEB 2016)

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