NASSN： a NAS-based storage network

With the digital information and application requirement on the Internet increasing fleetly nowadays,it is urgent to work out a network storage system with a large capacity,a high availability and scalability.To solve the above-mentioned issues,a NAS-based storage network(for short NASSN)has been designed.Firstly,the NASSN integrates multi-NAS,iNAS(an iSCSI-based NAS)and enterprise SAN with the help of storage virtualization,which can provide a greater capacity and better scalability.Secondly,the NASSN can provide high availability with the help of server and storage subsystem redundancy technologies.Thirdly,the NASSN simultaneously serves for both the file I/O and the block I/O with the help of an iSCSI module,which has the advantages of NAS and SAN.Finally,the NASSN can provide higher I/O speed by a high network-attached channel which implements the direct data transfer between the storage device and client.In the experiments,the NASSN has ultra-high-throughput for both of the file I/O requests and the block I/O requests.     

Fractional Order ［Proportional Integral］ Controllers Parameters Algorithm Based on the Vector Method

In forensic investigations,it is vital that the authenticity of digital evidence should be ensured. In addition,technical means should be provided to ensure that digital evidence collected cannot be misused for the purpose of perjury. In this paper,we present a method to ensure both authenticity and non-misuse of data extracted from wireless mobile devices. In the method,the device ID and a timestamp become a part of the original data and the Hash function is used to bind the data together. Encryption is applied to the data,which includes the digital evidence,the device ID and the timestamp. Both symmetric and asymmetric encryption systems are employed in the proposed method where a random session key is used to encrypt the data while the public key of the forensic server is used to encrypt the session key to ensure security and efficiency. With the several security mechanisms that we show are supported or can be implemented in wireless mobile devices such as the Android,we can ensure the authenticity and non-misuse of data evidence in digital forensics.     

Theoretical and metrical standardization of strain rate sensitivity index

Strain rate sensitivity index m is one of the vital mechanical parameters for determining material superplasticity. In this paper, the existing formulae for measuring m value are reviewed, and it is found that the m values can be classified into three classes mi under constant length, mv under constant velocity, and mp under constant load. The constraint equation of the generalized m value is established according to the tensile constitutive equation and the basis theory for plastic mechanics. Based on three typical deformation paths, the m value is redefined. Furthermore, from the formula of generalized m value, the formulae for measuring mi, mv and mp are theoretically deduced. The precise methods with numerical simulation are presented. The results prove that the m value is a non-constant and its dependence on (ε) changes with the deformation path. Under different deformation paths, the m values calculated from the same formula are different. Using different formulae, the m values under the same deformation path are also different. Therefore, deformation path and corresponding formula should be given during the measurement of the m value. Moreover, it is explained theoretically and experimentally that why the mv value under constant velocity is sometimes negative but the mp value under constant load is sometimes lager than 1. The aim of the analysis and measurement of the m value is to facilitate the study on the relationship between macroscopical mechanical laws and microscopic physical mechanisms during superplastic deformation.     

Small Segment Coalescing: A Hardware Acceleration Method of Receive Side for TCP/IP Processing

Dealing with a hardware acceleration method, small segment coalescing (SSC) was proposed to achieve the acceleration of TCP/IP processing in the receiving process. To reduce the number of data copy, CPU interruptions and TCP/IP processing, SSC combines small received TCP segments that belong to the same TCP/IP connection into a large TCP package in Network Interface Card (NIC). The whole process is implemented by hardware in NIC so that SSC remains transparent to upper drivers. Based on the intensive study on TCP/IP protocol and NIC mechanism, the coalescing policy is carefully designed to make sure that SSC can make a reasonable decision on whether or when to start or finish coalescing without delay. In addition, SSC is implemented and integrated into LCE5718, which is a totally self-designed dual-port Gigabit Ethernet controller. Finally, the simulation environment is constructed to verify the function of the design. A field programmable gate array (FPGA) prototype is set up, and experiments are conducted to show the performance of SSC in different configurations.     

Layered heuristic algorithm for multiple restriction routes

A layered algorithm by bidirectional searching is proposed in this paper to solve the problem that it is difficult and time consuming to reach an optimal solution of the route search with multiple parameter restrictions for good quality of service. Firstly, a set of reachable paths to each intermediate node from the source node and the sink node based on adjacent matrix transformation are calculated respectively. Then a temporal optimal path is selected by adopting the proposed heuristic method according to a non-linear cost function. When the total number of the accumulated nodes by bidirectional searching reaches n-2, the paths from two directions to an intermediate node should be combined and several paths via different nodes from the source node to the sink node can be obtained, then an optimal path in the whole set of paths can be taken as the output route. Some simulation examples are included to show the effectiveness and efficiency of the proposed method. In addition, the proposed algorithm can be implemented with parallel computation and thus, the new algorithm has better performance in time complexity than other algorithms. Mathematical analysis indicates that the maximum complexity in time, based on parallel computation, is the same as the polynomial complexity of O(kn2-3kn+k), and some simulation results are shown to support this analysis.     

Agitator tank device and drag reduction agent evaluation

The device that consists of tank and disk agitator for evaluation drag reduction agents(DRA) was established.The effect of DRA was defined by testing the changes of agitator torque that drives the disk rotation.The HG-DRA for oil pipeline from Linyi to Puyang was studied by agitator tank device.The relationships between the drag reduction rate and Reynolds number,concentration,balance time were studied.The best concentration and the highest Renords number for the best drag reduction rate were confirmed.The results show that the drag reduction rate tested in agitator tank is close to that in pipeline.The maximum error of drag reduction rate between pipeline and agitator tank is 18.3%,which indicates that the agitator tank device is available to evaluate the effect of DRA for pipeline and it also has the advantages of simple,easy to be operated and using small volume of oil.Those are very helpful for operaters to know the properties of DRA and operate pipeline well.     

Pseudo minimum translational distance between convex polyhedra (Ⅱ)——Robot collision-free path planning

By using the pseudo minimum translational distance between convex objects, this paper presents two algorithms for robot path planning. First, an analytically tractable potential field is defined in the robot configuration space, and the concept of virtual obstacles is introduced and incorporated in the path planner to handle the local minima of the potential function. Second, based on the Lipschitz continuity and differentiability of the pseudo minimum translational distance, the flexible-trajectory approach is implemented. Simulation examples are given to show the effectiveness and efficiency of the path planners for both mobile robots and manipulators.     

On the graph traversal method for evaluating linear binary-chain programs

Grahne et al. have presented a graph algorithm for evaluating a subset of recursive queries. This method consists of two phases. In the first phase, the method transforms a linear binary-chain program into a set of equations over expressions containing predicate symbols. In the second phase, a graph is constructed from the equations and the answers are produced by traversing the relevant paths. A new algorithm is described which requires less time than Grahne' s. The key idea of the improvement is to reduce the search space that will be traversed when a query is invoked. Further, the evaluation of cyclic data is speeded up by generating most answers directly in terms of the answers already found and the associated "path information" instead of traversing the corresponding paths as usual. In this way, this algorithm achieves a linear time complexity for both acyclic and most of cyclic data.     

Windows and Fieldbus Based Software Computer Numerical Control System

Computer numerical control(CNC)system is the base of modern digital and intelligent manufacturing technolo- gy.And opened its architecture and constituted based on PC and Windows operating system(OS)is the main trend of CNC sys- tem.However,even if the highest system priority is used in user mode,real-time capability of Windows(2000,NT,XP)for applications is not guaranteed.By using a device driver,which is running in kernel mode,the real time performance of Windows can be enhanced greatly.The acknowledgment performance of Windows to peripheral interrupts was evaluated.Harmonized with an intelligent real-time serial communication bus(RTSB),strict real-time performance can be achieved in Windows platform. An opened architecture software CNC system which is hardware independence is proposed based on PC and RTSB.A numerical control real time kernel(NCRTK),which is implemented as a device driver on Windows,is used to perform the NC tasks.Tasks are divided into real-time and non real-time.Real-time task is running in kernel mode and non real-time task is running in user mode.Data are exchanged between kernel and user mode by DMA and Windows Messages.     

DFT study on adduct reaction paths of GaN MOCVD growth

The adduct reaction paths for GaN growth by metal organic chemical vapor deposition (MOCVD) were studied by quantum chemical calculations employing density functional theory (DFT). Five possible adduct reaction paths with or without the ex-cess NH3were proposed and the corresponding potential energy surfaces were calculated. From the calculation results, it is concluded that after the formation of DMGNH2from TMG:NH3, the further decomposition paths have very slim probability because of the high energy barriers; whereas the oligomerization pathway to form oligomers [DMGNH2]x(x=2, 3) is probable,because of zero energy barrier. Since the oligomers tend to further polymerize, the nanoparticles are easily formed through this path. When NH3is in excess, TMG:NH3 tends to combine with the second NH3to form two new complexes: the coordination-bonded compound H3N:TMG:NH3and the hydrogen-bonded compound TMG:NH3 NH3. The formation of hydrogen-bonded compound TMG:NH3 NH3 will be more probable because of the lower energy than H3N:TMG:NH3. By comparing the potential energy surfaces in five adduct reaction paths, we postulate that, under the growth conditions of GaN MOCVD, the formation of hydrogen-bonded compound TMG:NH3 NH3 followed by the reversible decomposition may be the main reaction path for GaN thin film growth; while the adduct oligomerization path to generate oligomers [DMGNH2]2 and [DMGNH2]3might be the main reaction path for nanoparticles formation.     

Deduplication technology for the mobile flash

The performance, capacity and reliability of the flash memory on devices such as smartphones and the Internet of Things are limited. Deduplication can resolve these restrictions by removing the duplicate I/O, but must be done under various resource constraints on the device. This paper proposes the M-Dedupe deduplication, which applies content-aware deduplication I/O requests on critical paths, and improves the performance and efficiency of mobile phones by improving the efficiency of flash garbage collection. The prototype system verification results show that the M-Dedupe reduces the write data by an average of 23.7%~42.5%, the average write response time by 21.2%~39.8%, and the average erased block by 16.8%~43.9%. Besides, it can achieve high-deciding duplication in the mobile flash system, improve the deduplication efficiency, and save the storage space.     

PCI设备驱动程序的开发及应用

基于课题PCI总线数据采集卡的研制成功，要实现对卡上硬件资源(如内存、中断等)的访问，必须编写运行在核心态的设备驱动程序．详细介绍了在Windows2000操作系统下WDM驱动模型的基本原理及编写驱动程序时所面临的主要问题和解决方案．以DriverWorks为开发工具开发基于PCI局部总线的设备驱动程序，实现了可以访问PCI设备配置空间、物理内存、I／O端口及实现中断服务程序的PCI设备WDM驱动程序．最后通过大量的实验，验证了用此方法编写的驱动程序安全可靠，完全满足要求．     

面向嵌入式驱动软件开发的设备仿真技术研究

分析了传统嵌入式驱动软件开发模式的不足，提出了一种基于仿真设备的软硬件协同开发模式。详细论述了设备仿真技术的具体设计与实现，结合应用实例证明了该技术能较有效地缩短嵌入式驱动软件开发周期。     

USB通信驱动程序设计

讨论了电力系统故障仿真测试装置中USB通信驱动程序的开发.在视窗操作系统中,USB设备驱动程序根据WDM(视窗驱动程序模型)设计.在WDM驱动程序模型中,每个硬件设备至少有两个驱动程序,其中一个驱动程序称为功能驱动程序,通常就是硬件设备驱动程序.它了解使硬件工作的所有细节,负责初始化I/O操作,处理I/O操作完成时所带来的中断事件,为用户提供一种适合设备的控制方式;另一个由操作系统提供的驱动程序称为总线驱动程序,它负责管理硬件与计算机的连接.     

基于插件技术的OFFICE文档透明加密

个人应用环境对OFFICE文档文件加密的需求急剧增加．分析了文件加密系统、虚拟磁盘加密和过滤驱动加密应用于上述需求存在的缺陷,提出并实现一种基于插件技术的OFFICE文件加密系统．该系统具有透明、自主、直观、方便迁移的加密特点,适合个人加密应用．该系统目前可实现对WORD和EXCEL这2类OFFICE文档文件的加密．     

一种基于IP网络的远程数据同步方法

为了实现一种可靠的数据同步子系统,为上层应用系统提供透明的数据同步存储,提出了一种基于IP网络的远程数据同步方法。该方法模拟一个SCSI磁盘设备,支持标准的SCSI磁盘指令,并包含一个位于本地服务器上的本地磁盘和一个位于远程服务器上的远程磁盘。当向该磁盘设备写入数据时,一方面把数据写入本地磁盘,同时把数据通过IP网络发送到远程服务器写入远程磁盘,从而实现数据远程同步。该方法在保证生产系统业务连续性的条件下实现了数据的实时同步,提供廉价的异地数据同步存储,增强了应用系统的可靠性。     

DSP的通信协议栈的研究与实现

提出了一种基于TMS320C6415的嵌入式通信协议栈的实现方法。协议栈以TCP/IP/PPP为主,底层设计物理层协议,通过McBSP与信道调制解调的DSP进行数据帧收发,实现多DSP互连传输数据和物理信道状态通告;上层增加会话层,数据通过PCI总线接口与主机应用层协议进行通信,在DSP内部采用μC/OS-II完成多任务的调度管理。在Windows 2000上用Driver Studio设计实现cPCI的WDM驱动。实验结果表明,该协议栈具有结构紧凑、层次分明、传输速率高、回路延迟小的特点,符合设计要求。以之为基础开发的协议栈软件实现了远程测量通信。     

便携式大容量数据采集系统的设计与实现

为了满足数据采集系统大容量存储、便携和低功耗的要求，研制了新型便携式大容量数据采集系统。该系统主要由NAND型闪速存储器K9K1G08UOM、微控制器ADuC812和USB接口芯片PDIUSBDl2构成。K9K1G08UOM是存储容量为128M字节的串行结构芯片，I／O端口既作为地址和命令的输人口，又作为数据的输入／输出口，128M字节的存储空间需要27位地址，分为4个周期输入。ADuC812带有8通道、12位A／D转换器，该A／D转换器模块的各种功能通过3个寄存器SFR来设置。对微控制器而言，PDIUSBD12看起来就像一个带8位数据总线和一个地址位（占用两个位置）的存储器件。ADuC812的多位地址和数据总线可直接与PDIUSBD12的数据总线相连。试验结果表明，该系统能实时记录8通道128M字节的数据。带USB接口的设计保证了与PC机的高速数据传输和良好的人机界面。     

WINDOWS下I/O端口的访问技术

本文总结了在Windows3.X、Windows95和WindowsNT下I/O端口访问技术的差别;提出了在Windows3.X和Windows95下不写设备驱动程序,直接进行I/O的可行性.