87 research outputs found

    Rao\u27s Quadratic Entropy and Some New Applications

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    Many problems in statistical inference are formulated as testing the diversity of populations. The entropy functions measure the similarity of a distribution function to the uniform distribution and hence can be used as a measure of diversity. Rao (1982a) proposed the concept of quadratic entropy. Its concavity property makes the decomposition similar to ANOVA for categorical data feasible. In this thesis, after reviewing the properties and providing a modification to quadratic entropy, various applications of quadratic entropy are explored. First, analysis of quadratic entropy with the suggested modification to analyze the contingency table data is explored. Then its application to ecological biodiversity is established by constructing practically equivalent confidence intervals. The methods are applied on a real dinosaur diversity data set and simulation experiments are performed to study the validity of the intervals. Quadratic entropy is also used for clustering multinomial data. Another application of quadratic entropy that is provided here is to test the association of two categorical variables with multiple responses. Finally, the gene expression data inspires another application of quadratic entropy in analyzing large scale data, where a hill-climbing type iterative algorithm is developed based on a new minimum quadratic entropy criterion. The algorithm is illustrated on both simulated and real data

    Eyes grow towards mild hyperopia rather than emmetropia in Chinese preschool children

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    Purpose: To document one-year changes in refraction and refractive components in preschool children. Methods: Children, 3–5 years old, in the Jiading District, Shanghai, were followed for one year. At each visit, axial length (AL), refraction under cycloplegia (1% cyclopentolate), spherical dioptres (DS), cylinder dioptres (DC), spherical equivalent refraction (SER) and corneal curvature radius (CR) were measured. Results: The study included 458 right eyes of 458 children. The mean changes in DS, DC and SER were 0.02 ± 0.35 D, −0.02 ± 0.33 D and 0.01 ± 0.37 D, while the mean changes in AL, CR and lens power (LP) were 0.27 ± 0.10 mm, 0.00 ± 0.04 mm and − 0.93 ± 0.49 D. The change in the SER was linearly correlated with the baseline SER (coefficient = −0.147, p < 0.001). When the baseline SER was at 1.05 D (95% CI = 0.21 to 2.16), the change in SER was 0 D. The baseline SER was also linearly associated with the change in LP (coefficient = 0.104, p = 0.013), but not with the change in AL (p = 0.957) or with the change in CR (p = 0.263). Conclusion: In eyes with a baseline SER less than +1.00 D, LP loss was higher compared to axial elongation, leading to hyperopic shifts in refraction, whereas for those with baseline SER over this range, loss of LP compared to axial elongation was reduced, leading to myopic shifts. This model indicated the homeostasis of human refraction and explained how refractive development leads to a preferred state of mild hyperopia.The study was funded by Chinese National NatureScience Foundation (No. 81670898), Chinese Nat-ural Science Foundation for Young Staff (No.81800881), The Shanghai Three Year Public HealthAction Program (No. GWIV-3.3), The ShanghaiHigh-level Oversea Training Team Program on EyePublic Health (No. GWTD2015S08), The ShanghaiOutstanding Academic Leader Program (No.16XD1402300), Shanghai Nature Science Founda-tion (NO. 15ZR1438400), Three-year Action Pro-gram of Shanghai Municipality for Strengtheningthe Construction of the Public Health System(NO.GWIV-13.2), Key Discipline of PublicHealth-Eye health in Shanghai (No.15GWZK0601), Municipal Human ResourcesDevelopment Program for Outstanding YoungTalents in Medical and Health Sciences in Shanghai(Grant No. 2017YQ019), Shanghai Sailing Program(No. 17YF1416100), Foundation of ShanghaiMunicipal Commission of Health and FamilyPlanning (No. 20184Y0217), National Key R&DProgramofChina(2016YFC0904800,2019YFC0840607), National Science and Technol-ogy Major Project of China (2017ZX09304010) andSongjiang Science Foundation (No. 19SJKJGG30)

    Acute pain pathways:protocol for a prospective cohort study

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    INTRODUCTION: Opioid analgesics are often used to treat moderate-to-severe acute non-cancer pain; however, there is little high-quality evidence to guide clinician prescribing. An essential element to developing evidence-based guidelines is a better understanding of pain management and pain control among individuals experiencing acute pain for various common diagnoses. METHODS AND ANALYSIS: This multicentre prospective observational study will recruit 1550 opioid-naïve participants with acute pain seen in diverse clinical settings including primary/urgent care, emergency departments and dental clinics. Participants will be followed for 6 months with the aid of a patient-centred health data aggregating platform that consolidates data from study questionnaires, electronic health record data on healthcare services received, prescription fill data from pharmacies, and activity and sleep data from a Fitbit activity tracker. Participants will be enrolled to represent diverse races and ethnicities and pain conditions, as well as geographical diversity. Data analysis will focus on assessing patients’ patterns of pain and opioid analgesic use, along with other pain treatments; associations between patient and condition characteristics and patient-centred outcomes including resolution of pain, satisfaction with care and long-term use of opioid analgesics; and descriptive analyses of patient management of leftover opioids. ETHICS AND DISSEMINATION: This study has received approval from IRBs at each site. Results will be made available to participants, funders, the research community and the public. TRIAL REGISTRATION NUMBER: NCT04509115

    Enable Concurrent Byzantine Fault Tolerance Computing with Software Transactional Memory

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    Byzantine fault tolerance typically is achieved via state-machine replication, which requires the execution of all requests at the server replicas sequentially in a total order. This could severely limit the system throughput. We have seen tremendous efforts on the partial removal of the constraint on the sequential execution of all requests. Most of them rely on using application semantics to develop customized replication algorithms that could identify independent requests and execute them in parallel. In this paper, we describe concurrency control mechanisms for Byzantine fault tolerance systems using software transactional memory. This is an attractive approach to increasing the system throughput because no application-specific rules are required to determine whether or not two requests are conflicting. We present mechanisms for two common types of software transactional memory implementations, one based on transaction logs with two-phase locking, and the other based on multiversion concurrency control. We show that standard concurrency control mechanisms designed for these types cannot be used directly to ensure one-copy serializability, and introduce our solutions

    Enable Concurrent Byzantine Fault Tolerance Computing with Software Transactional Memory

    No full text
    Byzantine fault tolerance typically is achieved via state-machine replication, which requires the execution of all requests at the server replicas sequentially in a total order. This could severely limit the system throughput. We have seen tremendous efforts on the partial removal of the constraint on the sequential execution of all requests. Most of them rely on using application semantics to develop customized replication algorithms that could identify independent requests and execute them in parallel. In this paper, we describe concurrency control mechanisms for Byzantine fault tolerance systems using software transactional memory. This is an attractive approach to increasing the system throughput because no application-specific rules are required to determine whether or not two requests are conflicting. We present mechanisms for two common types of software transactional memory implementations, one based on transaction logs with two-phase locking, and the other based on multiversion concurrency control. We show that standard concurrency control mechanisms designed for these types cannot be used directly to ensure one-copy serializability, and introduce our solutions

    Intention preservation in deterministic multithreading: a partial solution

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    Deformation and fracture behaviours of a YAG single crystal characterized using nanoindentation method

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    In this work, nanoindentation tests were carried out to understand the deformation and fracture behaviours of yttrium aluminium garnet (YAG) single crystal. The elastic modulus, hardness and fracture toughness of the YAG crystal were 267.8 ± 1.3 GPa, 24.66 ± 0.37 GPa and 1.82 ± 0.23 MPa m, respectively. A pop-in was observed on the nanoindentation loading curve at approximately 1 mN load, associated with the occurrence of the elastic-plastic transition. When the indentation load was in the range of 1–6 mN, YAG deformed both elastically and plastically. Evident slip band along (−110) was observed beneath the indent impression. Dislocations, stacking faults, lattice bending and kinking were found in the plastically deformed subsurface. Radial cracks formed when the indentation load exceeded 6 mN, with the half-penny cracks initiated below the surface during unloading. The knowledge of the fracture toughness of YAG and the insights into its deformation behaviour under quasi-static contact attained from this study would greatly benefit the process optimization of ultra-precision machining of YAG single crystal

    SRSegNet: Super-resolution-assisted small targets polyp segmentation network with combined high and low resolution

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    Accurate and reliable segmentation of polyp targets is crucial in the treatment of colorectal cancer. However, in clinical practice, polyp structures represent only a small portion of the image, which is essential for the accurate diagnosis and treatment of colorectal cancer. The small size of lesion areas leads to a reduction in feature representation, thereby affecting the performance of traditional segmentation methods. To address this issue, To address this issue, recent advancements in segmentation methods for small medical objects meticulously extract feature information from these objects using attention mechanisms. However, these methods mainly focus on general small medical objects and perform poorly in the segmentation of small polyps.Therefore, this study fully exploits the advantages of joint learning and multi-task learning. By guiding the high-resolution features to guide the low-resolution encoder through joint learning and fusing effective features from the super-resolution task to assist the segmentation task, our method enhances the model’s ability to extract texture details. We also design a high-resolution guidance module and an information complementation module, effectively integrating learning between different resolutions and tasks.Evaluation experiments on two settings on the Kvasir-SEG, CVC-ClinicDB, CVC-ColonDB, CVC-300, and ETIS datasets demonstrate that our method achieves significant advantages in the segmentation of small polyps, outperforming various state-of-the-art methods

    Developing A Rule-Based Dynamic Safety Checking Method for Enhancing Construction Safety

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    Safety code compliance checking before construction is a key step in risk control. However, the conventional safety compliance checking methods are static model-oriented, which can lead to both the low adaptability of the model to the dynamic construction process, and low checking efficiency. This paper develops a dynamic safety checking method based on BIM and topology for enhancing construction safety management, by incorporating actual construction processes. Firstly, based on the four stages of automatic safety checking, a comprehensive dynamic safety checking framework is proposed. Secondly, the object attributes and spatial location in the BIM model are extracted to form a dynamic topological relationship database. Following this, the dynamic safety checking method is designed, and the checking results are intuitively reported to users based on BIM software. An actual construction scenery is taken as an example to verify the feasibility of the method in the final stage. The results showed that the dynamic safety checking method, based on topology and rules, can help to accurately identify safety risks in the pre-construction stage and reduce the safety risks due to poor design considerations or construction process modification
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