118 research outputs found

    Hopf-zero bifurcation of the ring unidirectionally coupled Toda oscillators with delay

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    In this paper, the Hopf-zero bifurcation of the ring unidirectionally coupled Toda oscillators with delay was explored. First, the conditions of the occurrence of Hopf-zero bifurcation were obtained by analyzing the distribution of eigenvalues in correspondence to linearization. Second, the stability of Hopf-zero bifurcation periodic solutions was determined based on the discussion of the normal form of the system, and some numerical simulations were employed to illustrate the results of this study. Lastly, the normal form of the system on the center manifold was derived by using the center manifold theorem and normal form method

    Completion Delay of Random Linear Network Coding in Full-Duplex Relay Networks

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    As the next-generation wireless networks thrive, full-duplex and relaying techniques are combined to improve the network performance. Random linear network coding (RLNC) is another popular technique to enhance the efficiency and reliability in wireless communications. In this paper, in order to explore the potential of RLNC in full-duplex relay networks, we investigate two fundamental perfect RLNC schemes and theoretically analyze their completion delay performance. The first scheme is a straightforward application of conventional perfect RLNC studied in wireless broadcast, so it involves no additional process at the relay. Its performance serves as an upper bound among all perfect RLNC schemes. The other scheme allows sufficiently large buffer and unconstrained linear coding at the relay. It attains the optimal performance and serves as a lower bound among all RLNC schemes. For both schemes, closed-form formulae to characterize the expected completion delay at a single receiver as well as for the whole system are derived. Numerical results are also demonstrated to justify the theoretical characterizations, and compare the two new schemes with the existing one

    Kernel Correlation-Dissimilarity for Multiple Kernel k-Means Clustering

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    The main objective of the Multiple Kernel k-Means (MKKM) algorithm is to extract non-linear information and achieve optimal clustering by optimizing base kernel matrices. Current methods enhance information diversity and reduce redundancy by exploiting interdependencies among multiple kernels based on correlations or dissimilarities. Nevertheless, relying solely on a single metric, such as correlation or dissimilarity, to define kernel relationships introduces bias and incomplete characterization. Consequently, this limitation hinders efficient information extraction, ultimately compromising clustering performance. To tackle this challenge, we introduce a novel method that systematically integrates both kernel correlation and dissimilarity. Our approach comprehensively captures kernel relationships, facilitating more efficient classification information extraction and improving clustering performance. By emphasizing the coherence between kernel correlation and dissimilarity, our method offers a more objective and transparent strategy for extracting non-linear information and significantly improving clustering precision, supported by theoretical rationale. We assess the performance of our algorithm on 13 challenging benchmark datasets, demonstrating its superiority over contemporary state-of-the-art MKKM techniques.Comment: 36 pages. This paper was accepted by Pattern Recognition on January 31, 202

    Implementation strategies to promote linkage to care for key populations after HIV self-testing: a scoping review

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    # Background In human immunodeficiency virus (HIV) care, key populations are sex workers, people who inject drugs, prisoners, transgender people, and men who have sex with men (MSM), who are at high risk and burden of HIV infection but face barriers to HIV prevention, treatment, and health services. HIV self-testing (HIVST) is effective in scaling up HIV testing uptake among key populations due to its cost-effective, confidential, and convenient feature. However, lacking linkage to care support remains a key challenge. This scoping synthesised the global evidence regarding implementing strategies to promote linkage to care for key populations after HIVST. # Methods This scoping review was conducted according to the Joanna Briggs Institute Manual for Evidence Synthesis. A data search was conducted on September 1, 2021. The searched databases were PubMed, Embase, EBSCOhost, Cochrane Library, Wan Fang Data (Chinese), China National Knowledge Infrastructure (Chinese), and Japan Medical Abstracts Society (Japanese). # Results Twenty studies from 2011 records met the eligibility criteria and were included for review. The study populations were MSM (9), mixed high-risk populations (7), female sex workers (3), and transgender youth (1). Implementation strategies to promote linkage to care for key populations after HIVST were classified into seven categories: 1) HIVST kits with linkage-to-care information, 2) web-based or mobile app-guided HIVST, 3) remote HIVST counselling, 4) intensive follow-up, 5) HIVST promotion through social media and key opinion leaders, 6) community engagement in HIVST and 7) financial incentive. The digital-supported intervention mainly targeted MSM in high-income settings, and the community-based approach and financial incentive strategies were mainly implemented in low and middle-income settings. Comparison of linkage outcomes between studies is problematic due to mixed interpretation and measurement of linkage to care after HIVST. # Conclusions Implementation strategies to promote linkage to care for key populations are diverse and should be incorporated in different settings and backgrounds. Innovative digital-supported HIVST research for female sex workers and high-risk populations in low and middle-income settings is warranted. A standardised definition of linkage to care following HIVST and a unified measurement of linkage outcomes should be developed and applied in future research

    Employability skills and self-perception of diploma 3 graduates in the world of work

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    This study aims to determine the world's perception of Diploma 3 graduates regarding work skills. The research used a questionnaire survey method on Diploma 3 graduates who had worked for 2-5 years. Measurement of work aspects includes individual qualities, basic skills, interpersonal skills, thinking skills, resource management, systems and technology, and information skills. The instrument's validity in each aspect ranges from 0.416 to 0.683, with a reliability of 0.882. The research technique used simple random sampling with 109 respondents in this study. The results of the study stated that the self-perception of graduates are (1) an individual quality score of 85.5 with a very high interpretation; (2) basic skills get a score of 81.8 with a high interpretation; (3) an interpersonal score of 84.8 with a very high interpretation; (4) thinking skills get a score of 83.1 with a very high interpretation; (5) resource management obtained a score of 88.6 with a very high interpretation; (6) systems and technology got a score of 92.4 with a very high interpretation, and (7) information skills got a score of 85.1 with a very high interpretation. Thus, the average worldwide employment of Diploma 3 graduates is 85.9, with a high interpretation. This finding implies that the higher graduates' employability skills, the higher their self-perception at work

    Vitamin D status and its association with parathyroid hormone concentrations in women of child-bearing age living in Jakarta and Kuala Lumpur.

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    Objective:To describe the vitamin D status of women living in two Asian cities, – Jakarta (6°S) and Kuala-Lumpur (2°N), to examine the association between plasma 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations, and to determine a threshold for plasma 25-hydroxyvitamin D above which there is no further suppression of PTH. Also, to determine whether dietary calcium intake influences the relationship between PTH and 25-hydroxyvitamin D.Design:Cross-sectional.Setting:Jakarta, Indonesia and Kuala Lumpur, Malaysia.Participants:A convenience sample of 504 non-pregnant women 18–40 years.Main measures:Plasma 25-hydroxyvitamin D and PTH.Results:The mean 25-hydroxyvitamin D concentration was 48 nmol/l. Less than 1% of women had a 25-hydroxyvitamin D concentration indicative of vitamin D deficiency (<17.5 nmol/l); whereas, over 60% of women had a 25-hydroxyvitamin D concentration indicative of insufficiency (<50 nmol/l). We estimate that 52 nmol/l was the threshold concentration for plasma 25-hydroxyvitamin D above which no further suppression of PTH occurred. Below and above this concentration the slopes of the regression lines were −0.18 (different from 0; P=0.003) and −0.01 (P=0.775), respectively. The relation between vitamin D status and parathyroid hormone concentration did not differ between women with low, medium or high calcium intakes (P=0.611); however, even in the highest tertile of calcium intake, mean calcium intake was only 657 mg/d.Conclusion:On the basis of maximal suppression of PTH we estimate an optimal 25-hydroxyvitamin D concentration of ∼ 50 nmol/l. Many women had a 25-hydroxyvitamin D below this concentration and may benefit from improved vitamin D status
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