Windows内核线程与用户线程共享缓冲区的实现

Windows操作系统实现了对内核的保护机制,用户级线程没有权限直接访问内核级缓冲区,不能直接与内核级线程共享缓冲区.研究了实现Windows内核线程与用户线程之间共享缓冲区的方法,包括DeviceIoControl方式和存储器映射方式,给出了部分源代码,同时分析了应用时应注意的问题.

用户级实时线程的设计与实现

连续媒质的应用程序要求有实时线程高效灵活的支持 ,包括对线程属性的动态管理和多线程模式的支持。本文介绍在RT

多线程技术

多线程技术已经在许多商用操作系统中实现，并即将在国产操作系统ＣＯＳＩＸＶ２．Ｘ系列中实现。由于多个线程共享同一个进程的地址空间，使得线程创建，线程之间的切换及通信的开销大大降低，因而很适合于多ＣＰＵ、多任务等并行环境下的处理。本文结合ＳｕｎＳｏｆｔＳｏｌａｒｉｓ２．Ｘ系列，从用户级多线程库和操作系统核心两个层次上，对多线程机制的实现进行了剖析。

分布式操作系统中线程包实现方法的对比研究

内核级线程是微内核操作系统的基本调度单位,较好地支持了细粒度的并行计算,但在支持用户分布式并发模型上还有许多缺点,而用户级线程是在核心线程的支持下建立的更高层次的用户级调度单位,能较好地支持用户程序的并发执行。文章重点分析了分布式操作系统中线程包的两种实现方法,并对比研究了它们的优缺点。

JAVA的多线程机制与多媒体技术

阐述多线程概念 ,JAVA多线程机制 ;提出将JAVA多线程组和线程优先级的机制运用在多媒体技术上 ;最后详细讨论一个基于JAVA多线程机制的。

线程模型实现机制的研究

随着计算模式由单处理机计算模式向多处理机计算模式的转变,传统的进程模型已不能适应新的计算模式的需要,必须引进线程模型,为此讨论了几种线程模型的实现方法。包括在不支持线程和支持线程的OS上实现线程模型的方法,以及在语言级实现线程模型的方法。这对操作系统的研究具有指导意义。

Chaboche强化模型的使用条件及适用性

基于结合Chaboche模型的ISO-KIN强化模型和Mises屈服准则,推导复杂加载模式下非线性混合强化材料模型,提出以出现反向加载来判定模拟过程中是否需要使用结合Chaboche模型的ISO-KIN强化模型的充分条件的应用原则。采用径向返回算法计算应力应变增量,实现其在有限元程序ABAQUS上进行板料塑性成形模拟的应用。以单凸型蒙皮和复杂S型蒙皮拉形工艺为例,计算不同材料强化模型对板料回弹量的影响,并与试验结果进行对比。结果表明,对于出现反向加载的复杂受力情况,相比于线性随动强化模型和各向同性强化模型,结合Chaboche模型的ISO-KIN强化模型对回弹的预测精度更高。

NEW REMOTE USER AUTHENTICATION SCHEME USING SMART CARD

Because the modified remote user authentication scheme proposed by Shen, Lin and Hwang is insecure, the Shen-Lin-Hwang＇ s scheme is improved and a new secure remote user authentication scheme based on the bi- linear parings is proposed. Moreover, the effectiveness of the new scheme is analyzed, and it is proved that the new scheme can prevent from all kinds of known attack. The one-way hash function is effective in the new scheme. The new scheme is proved that it has high effectiveness and fast convergence speed. Moreover, the ap- plication of the new scheme is easy and operational.

Modeling and Characterizing Internet Backbone Traffic

With enormous growth of the number of Internet users and appearance of new applications, characterization of Internet traffic has attracted more and more attention and has become one of the major challenging issues in telecommunication network over the past few years. In this paper, we study the network traffic pattern of the aggregate traffic and of specific application traffic, especially the popular applications such as P2P, VoIP that contribute most network traffic. Our study verified that majority Internet backbone traffic is contributed by a small portion of users and a power function can be used to approximate the contribution of each user to the overall traffic. We show that P2P applications are the dominant traffic contributor in current Internet Backbone of China. In addition, we selectively present the traffic pattern of different applications in detail.

User Identification Based on Multiple Attribute Decision Making in Social Networks

Social networks are becoming increasingly popular and influential,and users are frequently registered on multiple networks simultaneously,in many cases leaving large quantities of personal information on each network.There is also a trend towards the personalization of web applications;to do this,the applications need to acquire information about the particular user.To maximise the use of the various sets of user information distributed on the web,this paper proposes a method to support the reuse and sharing of user profiles by different applications,and is based on user profile integration.To realize this goal,the initial task is user identification,and this forms the focus of the current paper.A new user identification method based on Multiple Attribute Decision Making(MADM) is described in which a subjective weight-directed objective weighting,which is obtained from the Similarity Weight method,is proposed to determine the relative weights of the common properties.Attribute Synthetic Evaluation is used to determine the equivalence of users.Experimental results show that the method is both feasible and effective despite the incompleteness of the candidate user dataset.

Behavior Measurement Model Based on Prediction and Control of Trusted Network

In order to construct the trusted network and realize the trust of network behavior,a new multi-dimensional behavior measurement model based on prediction and control is presented.By using behavior predictive equation,individual similarity function,group similarity function,direct trust assessment function,and generalized predictive control,this model can guarantee the trust of an end user and users in its network.Compared with traditional measurement model,the model considers different characteristics of various networks.The trusted measurement policies established according to different network environments have better adaptability.By constructing trusted group,the threats to trusted group will be reduced greatly.Utilizing trusted group to restrict individuals in network can ensure the fault tolerance of trustworthiness of trusted individuals and group.The simulation shows that this scheme can support behavior measurement more efficiently than traditional ones and the model resists viruses and Trojans more efficiently than older ones.

Energy Efficient Power Allocation for Relay-Aided D2D Communications in 5G Networks

As one of the key technologies for the fifth generation(5G) wireless networks,device-to-device(D2D) communications allow user equipment(UE) in close proximity to communicate with each other directly.Forwarded by a relay,the relay-aided D2D(RA-D2D) communications can not only be applied to communications in much longer distance but also achieve a high quality of service(Qo S) .In this paper,we first propose a two-layer system model allowing RA-D2 D links to underlay traditional cellular uplinks.Then we maximize the energy efficiency of the RA-D2 D link while satisfying the minimum data-rate of the cellular link.The optimal transmit power at both D2 D transmitter and D2 D relay sides is obtained by transforming the nonlinear fractional programming into a nonlinear parameter programming.Simulation results show that our proposed power allocation method is more energy efficient than the existing works,and the proposed RA-D2 D scheme outperformed direct D2 D scheme when the distance between two D2 D users is longer.

Empirical Study on Customer Satisfaction Influencing Factors of Industry Application Products Based on Experiential Level Theory

The rapid development of industry application products has greatly influenced society. It has become essential for some telecommunication companies to focus on customer satisfaction with industrial products used by the government and enterprise customers. Following the review of a previous study of customer satisfaction and with the help of experiential level theory,this article attempts to establish a Satisfaction Factors Model for researching customer satisfaction with industry applications. We chose a product named "Mobile Monitor" and investigated the emotional satisfaction of 127 users and company leaders from different walks of life,and showed that 7 of the product's features affected the customers' overall emotional satisfaction. Lastly,this paper points out management implications of this application based on quantitative results. It presents a preliminary exploration program for customer satisfaction research in this specific field. The empirical research on a specific product based on experimental level theory may serve as a reference for other companies that desire to carry out similar surveys in future.

Quantifying Creep of Concrete Filled Steel Tubes

Using age adjusted effective modulus(AAEM)method,creep of concrete filled steel tube(CFST)member was formulated considering of creep coefficient and aging coefficient.Ten CFST specimens were tested including eight for creep and two for shrinkage.The experimental result was compared with the computed result using AAEM in which the creep coefficient was taken from calibration of ACI model based on experimental result on sealed concrete,and aging coefficient was supplied from relaxation test on sealed concrete specimen.Furthermore,the creep of CFST member was analyzed using author's own subroutine to input concrete properties through user programmable feature(UPF)in ANSYS software.Comparison was made on authors' own experimental database,some existing experimental results,and results from AAEM and numerical analysis.Finally,the conditions of applicability of AAEM method are put forward,and numerical approach to compute creep of CFST specimen is delineated.

Study on customization process and application via Internet

Networked customization is an important way for enterprises to satisfy customers?individual requirements. From this point of view, the study on networked customization process and application is started with analyzing the customization process in detail, in which the customization process is divided into 6 stages including information capture, need submission, need affirmation, need interaction, creating customization orders and customization production. A general customization process chart for common products is presented, which describes the communication between customers and enterprises in the entire customization process. The method of analyzing customization process is presented. The product customization subsystem in the system of ceramic product marketing and customization of Chongqing CHN & CHN Ceramics Co. Ltd. is introduced to explicate the process of customization via Internet.

Numerical Simulation of the Water Entry of a Structure in Free Fall Motion

To solve the problems concerning water entry of a structure, the RANS equations and volume of fluid （VOF） method are used. Combining the user-defined function （UDF） procedure with dynamic grids, the water impact on a structure in free fall is simulated, and the velocity, displacement and the pressure distribution on the structure are investigated. The results of the numerical simulation were compared with the experimental data, and solidly consistent results have been achieved, which validates the numerical model. Therefore, this method can be used to study the water impact problems of a structure.

Joint User Scheduling and Antenna Selection in Distributed Massive MIMO Systems with Limited Backhaul Capacity

Massive MIMO systems offer a high spatial resolution that can drastically increase the spectral and/or energy efficiency by employing a large number of antennas at the base station(BS).In a distributed massive MIMO system,the capacity of fiber backhaul that links base station and remote radio heads is usually limited,which becomes a bottleneck for realizing the potential performance gain of both downlink and uplink.To solve this problem,we propose a joint antenna selection and user scheduling which is able to achieve a large portion of the potential gain provided by the massive MIMO array with only limited backhaul capacity.Three sub-optimal iterative algorithms with the objective of sumrate maximization are proposed for the joint optimization of antenna selection and user scheduling,either based on greedy fashion or Frobenius-norm criteria.Convergence and complexity analysis are presented for the algorithms.The provided Monte Carlo simulations show that,one of our algorithms achieves a good tradeoff between complexity and performance and thus is especially fit for massive MIMO systems.

Privacy-Preserving Relative Location Based Services for Mobile Users

Location-aware applications have been used widely with the assistance of the latest positioning features in Smart Phone such as GPS,AGPS,etc.However,all the existing applications gather users' geographical data and transfer them into the pertinent information to give meaning and value.For this kind of solutions,the user's privacy and security issues might be raised because the geographical location has to be exposed to the service provider.A novel and practical solution is proposed in this article to provide the relative location of two mobile users based on their WiFi scanned results without any additional sensors.There is no privacy concern in this solution because end users will not collect and send any sensitive information to the server.This solution adopts a Client/Server(C/S) architecture,where the mobile user as a client reports the ambient WiFi APs and the server calculates the distances based on the WiFi AP's topological relationships.A series of technologies are explored to improve the accuracy of the estimated distance and the corresponding algorithms are proposed.We also prove the feasibility with the prototype of "Circle Your Friends" System(CYFS) on Android phone which lets the mobile user know the distance between him and his social network friends.

User Behaviors Analysis in Website Identification Registration

Nowadays, an increasing number of web applications require identification registration. However, the behavior of website registration has not ever been thoroughly studied. We use the database provided by the Chinese Software Develop Net (CSDN) to provide a complete perspective on this research point. We concentrate on the following three aspects: complexity, correlation, and preference. From these analyses, we draw the following conclusions: firstly, a considerable number of users have not realized the importance of identification and are using very simple identifications that can be attacked very easily. Secondly, there is a strong complexity correlation among the three parts of identification. Thirdly, the top three passwords that users like are 123456789, 12345678 and 11111111, and the top three email providers that they prefer are NETEASE, qq and sina. Further, we provide some suggestions to improve the quality of user passwords.