作者机构：
[Bian, Dong-fen] Beijing Inst Technol, Sch Math & Stat, Beijing 100081, Peoples R China.;[Fan, Li-li] Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.;[He, Lin] Chinese Acad Sci, Acad Math & Syst Sci, Inst Appl Math, Beijing 100190, Peoples R China.;[Zhao, Hui-jiang] Wuhan Univ, Sch Math & Stat, Wuhan 430072, Hubei, Peoples R China.;[Zhao, Hui-jiang] Wuhan Univ, Computat Sci Hubei Key Lab, Wuhan 430072, Hubei, Peoples R China.
通讯机构：
[Bian, Dong-fen] B;Beijing Inst Technol, Sch Math & Stat, Beijing 100081, Peoples R China.
关键词：
compressible Navier-Stokes equations;inflow problem;viscous shock wave;large density oscillations
摘要：
This paper is concerned with the inflow problem for one-dimensional compressible Navier-Stokes equations. For such a problem, Huang, Matsumura, and Shi showed in [4] that there exists viscous shock wave solution to the inflow problem and both the boundary layer solution, the viscous shock wave, and their superposition are time-asymptotically nonlinear stable provided that both the initial perturbation and the boundary velocity are assumed to be sufficiently small. The main purpose of this paper is to show that similar stability results still hold for a class of large initial perturbation which can allow the initial density to have large oscillations. The proofs are given by an elementary energy method and our main idea is to use the smallness of the strength of the viscous shock wave and the boundary velocity to control the possible growth of the solutions induced by the nonlinearity of the compressible Navier-Stokes equations and the inflow boundary condition. The key point in our analysis is to deduce the desired uniform positive lower and upper bounds on the density.
摘要：
It is well known that drivers can adjust their speeds based on forecasted traffic states in driving process, and this forecast behavior affects traffic features. In this paper, an improved car-following model with delay time, by incorporating the behavior of forecast speed difference, is proposed from the full velocity difference model. Its linear steady condition is deduced. Numerical simulations indicate that values of acceleration and deceleration of new model are more reasonable than those of the original model in starting and braking processes, and the kinematic wave speed is proper. Moreover, the behavior of forecast speed difference is found not only to smoothen the traffic fluctuation, but also to reduce the energy consumption in stable and unstable cases.
期刊：
CANADIAN MATHEMATICAL BULLETIN-BULLETIN CANADIEN DE MATHEMATIQUES,2019年62(4):727-740 ISSN：0008-4395
通讯作者：
Deng, Guotai
作者机构：
[Deng, Guotai] Cent China Normal Univ, Sch Math & Stat, Wuhan 430079, Hubei, Peoples R China.;[Deng, Guotai] Cent China Normal Univ, Hubei Key Lab Math Sci, Wuhan 430079, Hubei, Peoples R China.;[Liu, Chuntai] Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.;[Ngai, Sze-Man] Hunan Normal Univ, Key Lab High Performance Comp & Stochast Informat, Minist Educ China, Coll Math & Stat, Changsha 410081, Hunan, Peoples R China.;[Ngai, Sze-Man] Georgia Southern Univ, Dept Math Sci, Statesboro, GA 30460 USA.
通讯机构：
[Deng, Guotai] C;Cent China Normal Univ, Sch Math & Stat, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Hubei Key Lab Math Sci, Wuhan 430079, Hubei, Peoples R China.
摘要：
This study aims at investigating the reachable set estimation for delayed memristive neural networks (MNNs) with bounded disturbances. Under the framework of Filippov's solution and differential inclusion theory, a reachable set estimation criterion is established by means of Lyapunov functional. The obtained condition guarantees that all the states of MNNs are bounded. Moreover, a delay-dependent feedback controller design problem for MNNs is also considered. The exponential stability and stabilisability conditions are obtained. Two numerical examples are presented to demonstrate the usefulness of the proposed results.
期刊：
SIAM JOURNAL ON MATHEMATICAL ANALYSIS,2019年51(1):595-625 ISSN：0036-1410
通讯作者：
Ruan, Lizhi
作者机构：
[Fan, Lili] Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.;[Ruan, Lizhi] Cent China Normal Univ, Hubei Key Lab Math Phys, Sch Math & Stat, Wuhan 430079, Hubei, Peoples R China.;[Xiang, Wei] City Univ Hong Kong, Dept Math, Tat Chee Ave, Hong Kong, Peoples R China.
通讯机构：
[Ruan, Lizhi] C;Cent China Normal Univ, Hubei Key Lab Math Phys, Sch Math & Stat, Wuhan 430079, Hubei, Peoples R China.
摘要：
This paper is devoted to the study of the initial-boundary value problem on the half line for a one-dimensional radiative Euler equations, which is a system coupled by the classic compressible nonisentropic Euler equations with an elliptic equation. In particular, we focus our attention on the inflow problem when the velocity of the inward flow on the boundary is given as a positive constant. We give a rigorous proof of the asymptotic stability of the rarefaction wave without restrictions on the smallness of the wave strength, provided that the data on the boundary is supersonic. It is the first rigorous result on the initial-boundary value problem for the radiative Euler equations. New and subtle analysis is developed to overcome difficulties due to the boundary effect to derive energy estimates.
关键词：
Cloud data center;genetic algorithm (GA);multiobjective optimization (MOO);resource allocation;resource prediction
摘要：
In order to optimize the resource utilization of physical machines (PMs), the workload prediction of virtual machines (VMs) is vital but challenging. Most of existing literatures focus on either resource prediction or allocation individually, but both of them are highly correlated. In this paper, we propose a multiobjective genetic algorithm (GA) to dynamically forecast the resource utilization and energy consumption in cloud data center. We formulate a multiobjective optimization problem of resource allocation, which considers the CPU and memory utilization of VMs and PMs, and the energy consumption of data center. The proposed GA forecasts the resource requirement of next time slot according to the historical data in previous time slots. We further propose a VM placement algorithm to allocate VMs for next time slot based on the prediction results of GA. In our simulation-based analysis, the optimal solution for resource prediction under stable and unstable utilization tendency is found by the proposed GA. The prediction result is superior to the previous proposed Grey forecasting model. Results show that the proposed VM placement algorithm not only increases the average utilization level of CPU and memory but also decreases the energy consumption of cloud data center.
摘要：
In wireless sensor networks, sensor nodes collect plenty of data for each time period. If all of data are transmitted to a Fusion Center (FC), the power of sensor node would run out rapidly. On the other hand, the data also needs a filter to remove the noise. Therefore, an efficient fusion estimation model, which can save the energy of the sensor nodes while maintaining higher accuracy, is needed. This paper proposes a novel mixed H2/H∞-based energy-efficient fusion estimation model (MHEEFE) for energy-limited Wearable Body Networks. In the proposed model, the communication cost is firstly reduced efficiently while keeping the estimation accuracy. Then, the parameters in quantization method are discussed, and we confirm them by an optimization method with some prior knowledge. Besides, some calculation methods of important parameters are researched which make the final estimates more stable. Finally, an iteration-based weight calculation algorithm is presented, which can improve the fault tolerance of the final estimate. In the simulation, the impacts of some pivotal parameters are discussed. Meanwhile, compared with the other related models, the MHEEFE shows a better performance in accuracy, energy-efficiency and fault tolerance.
期刊：
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY,2018年26(5):1850061 ISSN：0218-348X
通讯作者：
Liu, Chuntai
作者机构：
[Liu, Chuntai] Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Liu, Chuntai] W;Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.
关键词：
Augment Tree;Cantor Set;Iterated Function System;Lipschitz Equivalence;Self-Similar Set
摘要：
Self-similarity and Lipschitz equivalence are two basic and important properties of fractal sets. In this paper, we consider those properties of the union of Cantor set and its translate. We give a necessary and sufficient condition that the union is a self-similar set. Moreover, we show that the union satisfies the strong separation condition if it is of the self-similarity. By using the augment tree, we characterize the Lipschitz equivalence between Cantor set and the union of Cantor set and its translate.
摘要：
Big data gathered from real systems, such as public infrastructure, healthcare, smart homes, industries, and so on, by sensor networks contain enormous value, and need to be mined deeply, which depends on a data storing and retrieving service. HBase is playing an increasingly important part in the big data environment since it provides a flexible pattern for storing extremely large amounts of unstructured data. Despite the fast-speed reading by RowKey, HBase does not natively support multi-conditional query, which is a common demand and operation in relational databases, especially for data analysis of ubiquitous sensing applications. In this paper, we introduce a method to construct a linear index by employing a Hilbert space-filling curve. As a RowKey generating schema, the proposed method maps multiple index-columns into a one-dimensional encoded sequence, and then constructs a new RowKey. We also provide a R-tree-based optimization to reduce the computational cost of encoding query conditions. Without using a secondary index mode, experimental results indicate that the proposed method has better performance in multi-conditional queries.
作者机构：
[Zhao, Juan] Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.;[Li, Zhitang] Huazhong Univ Sci & Technol, Network Ctr, Wuhan 430074, Peoples R China.;[Li, Zhitang] Natl Engn Lab Next Generat Internet Access Syst, Wuhan 430074, Peoples R China.
通讯机构：
[Zhao, Juan] W;Wuhan Polytech Univ, Sch Math & Comp Sci, Wuhan 430023, Hubei, Peoples R China.
关键词：
Reversible data hiding;Three-dimensional histogram shifting;Reversible watermarking;Reversible steganography;H.264
摘要：
<Abstract ID="Abs1" Language="En" OutputMedium="All"><Heading>Abstract</Heading><Para ID="Par1">Histogram shifting is an important method of reversible data hiding. However, every pixel, difference, or prediction-error is respectively changed to hide a data bit in the traditional histogram shifting, which constrains the capacity-distortion embedding performance. An efficient three-dimensional histogram shifting is proposed for reversible data hiding in this paper. Take H.264 videos as covers to show this method. In a 4?×?4 quantized discrete cosine transform luminance block, which is not inferred by others, three alternating current coefficients are selected randomly as an embeddable group. According to the different values of the selected coefficient groups, they could be divided into different sets. Data could be hidden according to these sets. In the traditional histogram shifting, only one information bit could be hidden with at most one modification of one coefficient, whereas two data bits could be hidden at the same cost by using the proposed scheme. The superiority of the presented technique is verified through experiments.</Para></Abstract>
