11,039 research outputs found

    Pion condensation in a soft-wall AdS/QCD model

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    Finite isospin chemical potential ÎĽI\mu_I and temperature TT have been introduced in the framework of soft-wall AdS/QCD model. By self-consistently solve the equation of motion, we obtain the phase boundary of pion condensation phase, across which the system undergoes a phase transition between pion condensation phase and normal phase. Comparing the free energy of solutions with and without pion condensation, we find that the phase transition is of first order type both at large ÎĽI\mu_I and small ÎĽI\mu_I. Qualitatively, the behavior at large ÎĽI\mu_I is in agreement with the lattice simulation in Phys.Rev.D66(2002)034505, while the behavior at small ÎĽI\mu_I is different from lattice simulations and previous studies in hard wall AdS/QCD model. This indicates that a full back-reaction model including the interaction of gluo-dynamics and chiral dynamics might be necessary to describe the small ÎĽI\mu_I pion condensation phase. This study could provide certain clues to build a more realistic holographic model.Comment: Regular article, 21 page

    Introduction to the Special Issue on Sustainable Solutions for the Intelligent Transportation Systems

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    The intelligent transportation systems improve the transportation system’s operational efficiency and enhance its safety and reliability by high-tech means such as information technology, control technology, and computer technology. In recent years, sustainable development has become an important topic in intelligent transportation’s development, including new infrastructure and energy distribution, new energy vehicles and new transportation systems, and the development of low-carbon and intelligent transportation equipment. New energy vehicles’ development is a significant part of green transportation, and its automation performance improvement is vital for smart transportation. The development of intelligent transportation and green, low-carbon, and intelligent transportation equipment needs to be promoted, a significant feature of transportation development in the future. For intelligent infrastructure and energy distribution facilities, the electricity for popular electric vehicles and renewable energy, such as nuclear power and hydrogen power, should be considered

    Design of Personnel Big Data Management System Based on Blockchain

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    With the continuous development of information technology, enterprises, universities and governments are constantly stepping up the construction of electronic personnel information management system. The information of hundreds of thousands or even millions of people’s information are collected and stored into the system. So much information provides the cornerstone for the development of big data, if such data is tampered with or leaked, it will cause irreparable serious damage. However, in recent years, electronic archives have exposed a series of problems such as information leakage, information tampering, and information loss, which has made the reform of personnel information management more and more urgent. The unique characteristics of the blockchain, such as non-tampering and traceability make it have great application potential in personnel information management, and can effectively solve many problems of traditional file management. However, the blockchain is limited by its own shortcomings such as small storage space and slow synchronization time, and cannot be directly applied to the big data field. This paper proposes a personnel management system based on blockchain, we analyzed the defects of the blockchain and proposed an improved method, constructs a novel data storage model of on-chain and out-of-chain that can effectively solve the problem of data redundancy and insufficient storage space. Based on this, we developed a prototype system with query, add, modify, and track personnel information, verified the feasibility of applying blockchain to personnel information management, explore the possibility of combining blockchain with big data

    Effect of a combination of omeprazole and high-dose proton pump inhibitors on the treatment of patients with liver cirrhosis complicated with upper gastrointestinal hemorrhage

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    Purpose: To determine the effect of a combination of omeprazole and high-dose proton pump inhibitor (PPI) on the treatment of patients with liver cirrhosis complicated with upper gastrointestinal hemorrhage.Methods: A total of 100 patients with liver cirrhosis and upper gastrointestinal hemorrhage who were admitted to Qingdao Chengyang District People’s Hospital from January 2019 to September 2020 were matched and randomly assigned to a control group and a study group. Patients in both groups received a high-dose PPI treatment, while those in the study group were given omeprazole in addition to highdose PPI. Total treatment effectiveness, incidence of adverse reactions, bleeding volume, hemostasis time, liver function after treatment, Quality of Life Index (QLI) scores, Visual Analogue Scale (VAS) scores, and bleeding (%) at 1, 2 and 4 weeks after treatment were compared for the two groups of patients.Results: Omeprazole-PPI combination produced a much more favorable outcome than treatment with only high-dose PPI, in terms of effectiveness, QLI scores and liver function (p < 0.05). The study group had significantly lower incidence of adverse reactions, bleeding volume, VAS scores, and degree of bleeding at 1, 2 and 4 weeks after treatment, as well as shorter hemostasis time, than the control group (p < 0.05).Conclusion: A combination treatment of omeprazole and high-dose PPI produces better therapeutic effect than high-dose PPI alone, in patients with liver cirrhosis and upper gastrointestinal hemorrhage

    Analysis on the Key Factors of the Network Separation in China in the Era of Telecommunications 4.0

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    The era of telecommunications 4.0 is a challenge to regulators and operators insofar as external environment, technology (such as SDN and NFV), and consumers’ requirements have changed. This paper’s main objective is to introduce and discuss several issues around the implementation of network separation as a regulatory remedy. The paper discusses network separation practice in several countries (including Sweden, the UK, Italy, Ireland, New Zealand, Australia and Singapore) and summarizes their advantages, disadvantages, process as well as effects. All findings are rendered in tabular form according to different separation modes which are accounting separation, functional separation, operational separation and ownership separation. Moreover, this paper discusses the main elements of a possible test for the adequacy of network separation. A sequential decision tree procedure with three questions is proposed: (1) Is there significant market power in China in the era of telecommunications 4.0? (2) Are there little vertical complementarities between services along the supply chain? (3) Is network separation a better regulatory tool than any other alternative remedy? By answering these three questions, the paper concludes that network separation is not suitable for China under the current situation

    Spatio-Temporal Kronecker Compressive Sensing for Traffic Matrix Recovery

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    A traffic matrix is generally used by several network management tasks in a data center network, such as traffic engineering and anomaly detection. It gives a flow-level view of the network traffic volume. Despite the explicit importance of the traffic matrix, it is significantly difficult to implement a large-scale measurement to build an absolute traffic matrix. Generally, the traffic matrix obtained by the operators is imperfect, i.e., some traffic data may be lost. Hence, we focus on the problems of recovering these missing traffic data in this paper. To recover these missing traffic data, we propose the spatio-temporal Kronecker compressive sensing method, which draws on Kronecker compressive sensing. In our method, we account for the spatial and temporal properties of the traffic matrix to construct a sparsifying basis that can sparsely represent the traffic matrix. Simultaneously, we consider the low-rank property of the traffic matrix and propose a novel recovery model. We finally assess the estimation error of the proposed method by recovering real traffic

    Spatio-Temporal Kronecker Compressive Sensing for Traffic Matrix Recovery

    Get PDF
    A traffic matrix is generally used by several network management tasks in a data center network, such as traffic engineering and anomaly detection. It gives a flow-level view of the network traffic volume. Despite the explicit importance of the traffic matrix, it is significantly difficult to implement a large-scale measurement to build an absolute traffic matrix. Generally, the traffic matrix obtained by the operators is imperfect, i.e., some traffic data may be lost. Hence, we focus on the problems of recovering these missing traffic data in this paper. To recover these missing traffic data, we propose the spatio-temporal Kronecker compressive sensing method, which draws on Kronecker compressive sensing. In our method, we account for the spatial and temporal properties of the traffic matrix to construct a sparsifying basis that can sparsely represent the traffic matrix. Simultaneously, we consider the low-rank property of the traffic matrix and propose a novel recovery model. We finally assess the estimation error of the proposed method by recovering real traffic

    Experimental investigation on permeability and mechanical deformation of coal containing gas under load

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    Coalbed effective permeability is widely used as a primary index to evaluate gas-drainage effect in CBM exploitation field. However, it seems to be difficult to obtain by the reason of dynamic change in close relationship with crustal stress, methane pressure, porosity, and adsorption. Due to their dissimilar adsorption properties and tectonic deformation degrees, different types of coal containing gas have various stress-strain and gas seepage curves. The paper presents the experimental investigations of the dynamic relationship between coal permeability and deformation under load. In this work, stress-strain and permeability investigations were performed using anthracite lump with a vitrinite reflectance of about 3.24% at various pressures and temperatures. The permeability (including the initial, minimum, and maximum) decreased with increasing temperature. At a constant confining pressure, the strains in different directions almost all increased with increasing axial stress and decreased with increasing pore methane pressure during the prefracture stage. At a constant pore pressure, the compression strength of the coal specimens increased approximately linearly during the prefracture stage and sharply decreased during the postfracture stage, while the permeability decreased rapidly and then increased slowly during the prefracture and remained stable during the postfracture stage. The permeability of the coal specimens mainly depended on the inner fissures. The permeability was greater during the postfracture than that during the prefracture stage. At the same temperature, the gas seepage curve of each coal specimen could be divided into three sections: decreasing, increasing, and constant sections. The necessary time for the permeability to reach a steady state increased as the confining and pore pressures increased. At high confining pressures (i.e., 6 MPa and 8 MPa), no significant differences between the methane seepage velocities of the specimens were evident, and their seepage curves were similar to prefracture. However, clear differences were observable at the postfracture stage. The seepage abilities of the coal specimens were more sensitive to stress than temperature in the same condition
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