7,000 research outputs found

    Segmentation of ultrasound images of thyroid nodule for assisting fine needle aspiration cytology

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    The incidence of thyroid nodule is very high and generally increases with the age. Thyroid nodule may presage the emergence of thyroid cancer. The thyroid nodule can be completely cured if detected early. Fine needle aspiration cytology is a recognized early diagnosis method of thyroid nodule. There are still some limitations in the fine needle aspiration cytology, and the ultrasound diagnosis of thyroid nodule has become the first choice for auxiliary examination of thyroid nodular disease. If we could combine medical imaging technology and fine needle aspiration cytology, the diagnostic rate of thyroid nodule would be improved significantly. The properties of ultrasound will degrade the image quality, which makes it difficult to recognize the edges for physicians. Image segmentation technique based on graph theory has become a research hotspot at present. Normalized cut (Ncut) is a representative one, which is suitable for segmentation of feature parts of medical image. However, how to solve the normalized cut has become a problem, which needs large memory capacity and heavy calculation of weight matrix. It always generates over segmentation or less segmentation which leads to inaccurate in the segmentation. The speckle noise in B ultrasound image of thyroid tumor makes the quality of the image deteriorate. In the light of this characteristic, we combine the anisotropic diffusion model with the normalized cut in this paper. After the enhancement of anisotropic diffusion model, it removes the noise in the B ultrasound image while preserves the important edges and local details. This reduces the amount of computation in constructing the weight matrix of the improved normalized cut and improves the accuracy of the final segmentation results. The feasibility of the method is proved by the experimental results.Comment: 15pages,13figure

    Deformation effect on the center-of-mass correction energy in nuclei ranging from Oxygen to Calcium

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    The microscopic center-of-mass (c.m.) correction energies for nuclei ranging from Oxygen to Calcium are systematically calculated by both spherical and axially deformed relativistic mean-field (RMF) models with the effective interaction PK1. The microscopic c.m. correction energies strongly depend on the isospin as well as deformation and deviate from the phenomenological ones. The deformation effect is discussed in detail by comparing the deformed with the spherical RMF calculation. It is found that the direct and exchange terms of the c.m. correction energies are strongly correlated with the density distribution of nuclei and are suppressed in the deformed case.Comment: 7 pages, 3 figures, accepted by Chin.Phys.Let

    Deformation effect on the center-of-mass correction energy in nuclei ranging from Oxygen to Calcium

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    The microscopic center-of-mass (c.m.) correction energies for nuclei ranging from Oxygen to Calcium are systematically calculated by both spherical and axially deformed relativistic mean-field (RMF) models with the effective interaction PK1. The microscopic c.m. correction energies strongly depend on the isospin as well as deformation and deviate from the phenomenological ones. The deformation effect is discussed in detail by comparing the deformed with the spherical RMF calculation. It is found that the direct and exchange terms of the c.m. correction energies are strongly correlated with the density distribution of nuclei and are suppressed in the deformed case.Comment: 7 pages, 3 figures, accepted by Chin.Phys.Let

    1-(4-Methyl­phenyl­sulfon­yl)-5-phenyl-4,5-dihydro-1H-pyrazole

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    The title compound, C16H16N2O2S, was synthesized by the reaction of 5-phenyl-4,5-dihydro-1H-pyrazole and 4-methyl­benzene-1-sulfonyl chloride. The five-membered pyrazoline ring is nearly planar, with a miximum deviation of 0.078 (2) Å

    Theoretical investigation of the thermal performance of a novel solar loop-heat-pipe façade-based heat pump water heating system

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    The aim of the paper was to present a dedicated theoretical investigation into the thermal performance of a novel solar loop-heat-pipe façade based heat pump water heating system. This involved thermo-fluid analyses, computer numerical model development, the model running up, modelling result analyses and conclusion. An energy balance network was established on each part and the whole range of the system to address the associated energy conversion and transfer processes. On basis of this, a computer numerical model was developed and run up to predict the thermal performance of such a system at different system configurations, layouts and operational conditions. It was suggested that the loop heat pipes could be filled with either water, R134a, R22 or R600a; of which R600a is the favourite working fluid owing to its relatively larger heat transfer capacity and positive pressure in operation. Variations in the system configuration, i.e., glazing covers, heat exchangers, would lead to identifiable differences in the thermal performance of the system, represented by the thermal efficiency and COP. Furthermore, impact of the external operational parameters, i.e., solar radiation and ambient air temperature, to the system's thermal performance was also investigated. The research was based on an innovative loop-heat-pipe façade and came up with useful results reflecting the thermal performance of the combined system between the façade and heat pump. This would help promote development and market penetration of such an innovative solar heating technology, and thus contribute to achieving the global targets in energy saving and carbon emission reduction

    Interactions of Bargaining Power and Introduction of Online Channel in Two Competing Supply Chains

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    This paper studies the effect of dual-channel format on supply chain’s competition ability and the effect of different bargaining powers on the competition between two supply chains and the optimal pricing decisions of all supply chain members when one supply chain introduces an online retailing channel. We develop four game models and obtain the optimal pricing decisions in closed form of these models and give some sensitivity analysis through numerical approach. Some new managerial insights are obtained as follows: Regardless of the two supply chain members’ bargaining forms, the optimal price, the maximal demand, and the maximal profit decrease as the self-price sensitivity decreases. The industry holds advantage in getting higher profit when the supply chain without online retailing channel is led by the retailer. In addition, we find that a manufacturer as a leader of its supply chain can get more profit when the competing supply chain’s leader is the manufacturer than when the competing supply chain’s leader is the retailer

    Evaluation of Governance Risk in Industry-University-Research Collaborative Innovation Project: Based on BP Neural Networks

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    Funding: This research was funded by [Projects of the National Social Science Foundation of China] grant number [18BGL020] Abstract Effective evaluation of project governance risks is of great significance to the successful implementation of industry-university-research collaborative innovation project. By introducing the idea of project governance into risk management in industry-university-research collaborative innovation project, this paper analyzes governance risk sources from four aspects, based on the project characteristics, which include the background of participators, organizational structure, project objectives and the relationship of the main participators from the view of project governance. The governance risks are categorized as structure risk, morality risk and behavior risk. The evaluation system of governance risk in Industry-University-Research collaborative innovation project is established. The BP neural network model is applied to assess risk and the MATLAB is used to process data according to the features of project governance risk and theory analysis. Finally, the model is checked by empirical test. This model solves the problem that the risks are difficult to quantify. Scientific nature of the feasibility of the evaluation is improved by the model. At the same time, not only the research field of project governance risk but also risk research of industry-university-research collaborative innovation project is extended. Keywords: industry-university-research, collaborative innovation, project governance risk, risk origin, BP neural network
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