789 research outputs found

    Efficient algorithms for dilated mappings of binary trees

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    The problem is addressed to find a 1-1 mapping of the vertices of a binary tree onto those of a target binary tree such that the son of a node on the first binary tree is mapped onto a descendent of the image of that node in the second binary tree. There are two natural measures of the cost of this mapping, namely the dilation cost, i.e., the maximum distance in the target binary tree between the images of vertices that are adjacent in the original tree. The other measure, expansion cost, is defined as the number of extra nodes/edges to be added to the target binary tree in order to ensure a 1-1 mapping. An efficient algorithm to find a mapping of one binary tree onto another is described. It is shown that it is possible to minimize one cost of mapping at the expense of the other. This problem arises when designing pipelined arithmetic logic units (ALU) for special purpose computers. The pipeline is composed of ALU chips connected in the form of a binary tree. The operands to the pipeline can be supplied to the leaf nodes of the binary tree which then process and pass the results up to their parents. The final result is available at the root. As each new application may require a distinct nesting of operations, it is useful to be able to find a good mapping of a new binary tree over existing ALU tree. Another problem arises if every distinct required binary tree is known beforehand. Here it is useful to hardwire the pipeline in the form of a minimal supertree that contains all required binary trees

    Efficient algorithms for a class of partitioning problems

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    The problem of optimally partitioning the modules of chain- or tree-like tasks over chain-structured or host-satellite multiple computer systems is addressed. This important class of problems includes many signal processing and industrial control applications. Prior research has resulted in a succession of faster exact and approximate algorithms for these problems. Polynomial exact and approximate algorithms are described for this class that are better than any of the previously reported algorithms. The approach is based on a preprocessing step that condenses the given chain or tree structured task into a monotonic chain or tree. The partitioning of this monotonic take can then be carried out using fast search techniques

    Design and Implementation of Lightweight Certificateless Secure Communication Scheme on Industrial NFV-Based IPv6 Virtual Networks

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    With the fast growth of the Industrial Internet of Everything (IIoE), computing and telecommunication industries all over the world are moving rapidly towards the IPv6 address architecture, which supports virtualization architectures such as Network Function Virtualization (NFV). NFV provides networking services like routing, security, storage, etc., through software-based virtual machines. As a result, NFV reduces equipment costs. Due to the increase in applications on Industrial Internet of Things (IoT)-based networks, security threats have also increased. The communication links between people and people or from one machine to another machine are insecure. Usually, critical data are exchanged over the IoE, so authentication and confidentiality are significant concerns. Asymmetric key cryptosystems increase computation and communication overheads. This paper proposes a lightweight and certificateless end-to-end secure communication scheme to provide security services against replay attacks, man-in-the-middle (MITM) attacks, and impersonation attacks with low computation and communication overheads. The system is implemented on Linux-based Lubuntu 20.04 virtual machines using Java programming connected to NFV-based large-scale hybrid IPv4-IPv6 virtual networks. Finally, we compare the performance of our proposed security scheme with existing schemes based on the computation and communication costs. In addition, we measure and analyze the performance of our proposed secure communication scheme over NFV-based virtualized networks with regard to several parameters like end-to-end delay and packet loss. The results of our comparison with existing security schemes show that our proposed security scheme reduces the computation cost by 38.87% and the communication cost by 26.08%

    Analysis of Brain Imaging Data for the Detection of Early Age Autism Spectrum Disorder Using Transfer Learning Approaches for Internet of Things

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    In recent years, advanced magnetic resonance imaging (MRI) methods including functional magnetic resonance imaging (fMRI) and structural magnetic resonance imaging (sMRI) have indicated an increase in the prevalence of neuropsychiatric disorders such as autism spectrum disorder (ASD), effects one out of six children worldwide. Data driven techniques along with medical image analysis techniques, such as computer-assisted diagnosis (CAD), benefiting from deep learning. With the use of artificial intelligence (AI) and IoT-based intelligent approaches, it would be convenient to support autistic children to adopt the new atmospheres. In this paper, we classify and represent learning tasks of the most powerful deep learning network such as convolution neural network (CNN) and transfer learning algorithm on a combination of data from autism brain imaging data exchange (ABIDE I and ABIDE II) datasets. Due to their four-dimensional nature (three spatial dimensions and one temporal dimension), the resting state-fMRI (rs-fMRI) data can be used to develop diagnostic biomarkers for brain dysfunction. ABIDE is a collaboration of global scientists, where ABIDE-I and ABIDE-II consists of 1112 rs-fMRI datasets from 573 typical control (TC) and 539 autism individuals, and 1114 rs-fMRI from 521 autism and 593 typical control individuals respectively, which were collected from 17 different sites. Our proposed optimized version of CNN achieved 81.56% accuracy. This outperforms prior conventional approaches presented only on the ABIDE I datasets

    Maximally spatial-disjoint lightpaths in optical networks

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    Lightpaths enable end-to-end all-optical transmission between network nodes. For survivable routing, traffic is often carried on a primary lightpath, and rerouted to another disjointed backup lightpath in case of the failure of the primary lightpath. Though both lightpaths can be physically disjointed, they can still fail simultaneously if a disaster affects them simultaneously on the physical plane. Hence, we propose a routing algorithm for provisioning a pair of link-disjoint lightpaths between two network nodes such that the minimum spatial distance between them (while disregarding safe regions) is maximized. Through means of simulation, we show that our algorithm can provide higher survivability against spatial-based simultaneous link failures (due to the maximized spatial distance)

    Selective harmonic elimination in awide modulation range using modified Newton-raphson and pattern generation methods for a multilevel inverter

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    Considering the aim of having low switching losses, especially in medium-voltage and high-power converters, the pre-programmed pulse width modulation technique is very useful because the generated harmonic content can be known in advance and optimized. Among the different low switching frequency techniques, the Selective Harmonics Elimination (SHE) modulation method is most suitable because of its direct control over the harmonic spectrum. This paper proposes a method for obtaining multiple solutions for selectively eliminating specific harmonics in a wide range of modulation indices by using modified Newton-Raphson (NR) and pattern generation techniques. The different pattern generation and synthesis approach provide more degrees of freedom and a way to operate the converter in a wide range of modulation. The modified Newton-Raphson technique is not complex and ensures fast convergence on a solution. Moreover, multiple solutions are obtained by keeping a very small increase in the modulation index. In the previous methods, solutions were not obtainable at all modulation indices. In this paper, only exact solutions to the low-order harmonics elimination for Cascaded H-bridge inverter are reported for all modulation indices. Analytical and simulation results prove the robustness and correctness of the technique proposed in this paper. 2018 by the authors.Acknowledgments: This (publication, report, etc.) was made possible by NPRP grant # [X-033-2-007] from the Qatar National Research Fund (a member of Qatar Foundation).Scopu

    2-Carboxy­anilinium chloride monohydrate

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    In the mol­ecule of the title compound, C7H8NO2 +·Cl−·H2O, an intra­molecular N—H⋯O hydrogen bond results in the formation of a non-planar six-membered ring adopting a flattened boat conformation. In the crystal structure, inter­molecular O—H⋯O and N—H⋯Cl hydrogen bonds link the mol­ecules. There is a C=O⋯π contact between the carbonyl unit and the centroid of the benzene ring. There is a C=O⋯π contact [C⋯Cg = 3.5802 (18), C—O⋯Cg = 89 (1)°] between the carbonyl unit and the centroid of the benzene ring

    (2E)-3-(4-Chloro­phen­yl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one

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    In the mol­ecule of the title compound, C13H10ClNO, the benzene and pyrrole rings are oriented at a dihedral angle of 7.37 (12)°. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric R 2 2(10) dimers. There are C—H⋯π inter­actions between benzene and pyrrole rings and a benzene C—H group. A weak π–π inter­action between the pyrrole rings [centroid–centroid distance 3.8515 (11) Å] further stabilizes the structure. There is also a π inter­action between the pyrrole ring and the carbonyl group, with a carbon–centroid distance of 3.4825 (18) Å

    Comparison of oral versus injectable vitamin-D for the treatment of nutritional vitamin-D deficiency rickets

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    OBJECTIVE: To assess the safety and acceptability of a single dose of vitamin-D versus the efficacy of injectable Vitamin-D versus oral vitamin-D. STUDY DESIGN: Case control. PLACE AND DURATION OF STUDY: It was carried out at the Department of Paediatrics, Kharadar General Hospital, Karachi, from August 2003 to April 2004. METHODOLOGY: Children of the age of 6 months to 3 years with clinical, biochemical and radiological evidence of vitamin- D deficiency rickets were included. The history, clinical examination, complete blood picture, serum calcium. Phosphorus, alkaline phosphatase and X-ray of wrist joint were done. The children were divided into two groups A and B. Group A was given oral vitamin-D and group B was given intramuscular injection of vitamin-D on the first day and then they were followed for two more visits at 30 and 90 days with clinical, biochemical and radiological examinations to assess the outcome. RESULTS: There were 50 confirmed cases of rickets in each group. The mean age was 10.9+5.1 months and 14.7+8.1 months in group A and B respectively. In these children, clinical features were weakness, difficulty in walking, frontal bossing, ribcage deformity and widening of wrist were seen. After one dose of vitamin-D (cholecalciferol), there was appreciable gain of weight and height and raised levels of alkaline phosphatase became normal during follow-up. Radiological florid rickets and non-florid rickets in both groups healed clinically during follow-up period. Oral and injectable forms of vitamin-D (cholecalciferol) were effective but injectable form was shown to be statistically significant. There were no undesirable side effects and both forms of treatment were well-tolerated

    Comparison of oral versus injectable vitamin-D for the treatment of nutritional vitamin-D deficiency rickets

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    OBJECTIVE: To assess the safety and acceptability of a single dose of vitamin-D versus the efficacy of injectable Vitamin-D versus oral vitamin-D. STUDY DESIGN: Case control. PLACE AND DURATION OF STUDY: It was carried out at the Department of Paediatrics, Kharadar General Hospital, Karachi, from August 2003 to April 2004. METHODOLOGY: Children of the age of 6 months to 3 years with clinical, biochemical and radiological evidence of vitamin- D deficiency rickets were included. The history, clinical examination, complete blood picture, serum calcium. Phosphorus, alkaline phosphatase and X-ray of wrist joint were done. The children were divided into two groups A and B. Group A was given oral vitamin-D and group B was given intramuscular injection of vitamin-D on the first day and then they were followed for two more visits at 30 and 90 days with clinical, biochemical and radiological examinations to assess the outcome. RESULTS: There were 50 confirmed cases of rickets in each group. The mean age was 10.9+5.1 months and 14.7+8.1 months in group A and B respectively. In these children, clinical features were weakness, difficulty in walking, frontal bossing, ribcage deformity and widening of wrist were seen. After one dose of vitamin-D (cholecalciferol), there was appreciable gain of weight and height and raised levels of alkaline phosphatase became normal during follow-up. Radiological florid rickets and non-florid rickets in both groups healed clinically during follow-up period. Oral and injectable forms of vitamin-D (cholecalciferol) were effective but injectable form was shown to be statistically significant. There were no undesirable side effects and both forms of treatment were well-tolerated
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