Multiproject staff scheduling with variable resource constraints

An analytical approach and a PC software based solution are presented to a project management problem, in which multiple resources must be allocated to perform both routine tasks and a set of projects with varying levels of priority. The performance of a priority-based decision rule was tested on this project management problem. The model was able to provide division-level management with an effective tool for staff workload planning and program management. A sequential, iterative approach is developed and used to test and evaluate alternative PC commercial software on a set of projects and evolving criteria. A PC commercial software package, with associated heuristics, is demonstrated to provide useful results to multiproject staff scheduling problems in an actual organization     

Media synchronization in multimedia Web using a neuro-fuzzyframework

We consider the problem of multimedia synchronization in a Web environment. The workload generated by the multimedia server during a Web session exhibits variations that are quite different from the traffic fluctuation offered by a single media stream, e.g., a variable bit rate (VBR) video. We propose a set of parameters that can be used to characterize the workload generated by the multimedia server in a Web-type browsing environment. The workload characterization scheme is subsequently used in designing a server-based synchronization scheme. The problem of scheduling multimedia information to ensure media synchronization in a Web environment is identified as a multicriteria scheduling problem, which is NP-hard. The ability of fuzzy control to deal with multivariables makes it a good alternative for the multicriteria scheduling problem considered. Consequently, we propose a neuro-fuzzy scheduler (NFS) that makes an intelligent compromise among multicriteria by properly combining some scheduling heuristics. Performance of the NFS is compared with several known heuristics and a branch and bound algorithm. The results show that the proposed NFS ran dynamically adjust to the varying workload quite well     

移动对象全局K最接近邻居查询研究

基于两个对象在一段时间内的范围距离度量,给出了一种新的时空查询形式-全局最接近邻居查询。该查询检索移动对象在一段时间内范围距离最小的运动对象。通过考察查询和连续最接近邻居之间关系,给出了一个基本查询处理算法。根据数据对象集的运动性不同,精化了运动和静止数据集下的全局距离的定义,并对R树结构索引的数据集给出了裁减、更新和访问启发式规则。采用分支界定技术和给出的启发式规则,设计了迭代的深度优先和基于堆的最好优先的查询处理算法。大量的实验表明,最好优先的查询处理算法具有突出的性能。     

智能测量集成电路的设计与仿真

文章以电子体重秤专用集成电路为例,介绍了基于嵌入式MPU的智能测量专用集成电路的设计及硬件仿真。在一块芯片内实现了数据采集、数据处理、数据显示等智能测量系统所需完成的功能,并在所设计的硬件仿真系统中,通过硬件仿真,验证了系统功能的正确性,为目标芯片提供了软件开发平台。并且该设计具有较强的通用性,可用于多种智能测量场合。     

Statistical simulation methods for investigating the structure ofreliability optimization

Qualitative and quantitative techniques for reliability sampling plants are described. An example shows how to apply the techniques to detect service life and the effectiveness of reliability. The relationships between sample size, confidence limits number of failed units during the test, and the fraction of reliable units is shown. By statistical simulation, 55 practical sampling plans were developed. The statistical simulation, with the aid of finite differences and computer analysis, provided a good solution of the authors' research problems. The distribution of the data corresponds rather accurately to the given curves, which are the inverses of the functions of the theoretical distribution based on the formalised approach     

信任驱动的网格作业调度算法

针对目前网格资源管理中信任机制与作业调度机制分离的缺陷,基于网格信任模型与信任效益函数,提出了信任驱动的网格作业调度问题。对传统批作业调度算法进行信任扩展,提出了两种信任驱动的网格作业调度启发式。对信任驱动网格作业调度算法进行大规模仿真实验,有力地证明了信任驱动算法优于传统时间驱动算法,在平均信任效益和总信任效益等方面具有较好的综合性能。     

基于MACR和CAL启发式的求差知识编译算法

DKCHER算法是基于超扩展规则的求差知识编译算法.本文首先研究了DKCHER算法的执行流程,并定义了互补量的概念,然后设计了启发式策略MACR（maximum complementary amount of clauses with middle result）,用于动态选择与中间结果互补量最大的子句.针对互补展开过程,设计了动态启发式策略CAL（optimal sequence sorted by complementary amount of literals）,将互补展开中的文字按照与输入公式互补量的大小进行排序并展开.将上述两种启发式策略与DKCHER算法相结合,分别设计了MACR_DKCHER算法、CAL_DKCHER算法和MACR_CAL_DKCHER算法.实验结果表明,MACR启发式策略能够提升DKCHER算法的编译效率和编译质量,编译效率最高可提升9倍,编译质量最高可提升1.9倍;CAL启发式策略在子句数和变量数比值较大的实例上,能够提高DKCHER算法的编译效率,但会降低DKCHER算法的编译质量;MACR_CAL启发式最高可将DKCHER算法的编译效率提高12倍,但会导致DKCHER算法的编译质量有所降低.     

Broadcast Data Allocation for Efficient Access of Multiple Data Items in Mobile Environments

The issue of data broadcast has received much attention in mobile computing. A periodic broadcast of frequently requested data can reduce the workload of the up-link channel and facilitate data access for the mobile user. Many approaches have been proposed to schedule data items for broadcasting. However, the issues of accessing multiple data items on the broadcast channel are less discussed. Two problems are discussed in this paper, that is, deciding the content of the broadcast channel based on the queries from the clients, and scheduling the data items to be broadcast. We will show that these two problems are NP-complete. Different heuristics to these problems are presented and compared through performance evaluations.     

一种基于IMM的自适应跟踪数据率算法

针对交互式多模型(IMM),提出一种自适应跟踪数据率的算法.该算法利用IMM模型更新概率对各模型产生的采样间隔时间进行混合估计,产生系统的自适应采样间隔时间.在保证跟踪精度的基础上,有效地降低了跟踪采样次数.仿真结果表明了方法的有效性.     

智能测控电路片上系统的设计与仿真

智能测量控制电路在工业测控及各类消费产品中应用极广,介绍了其基于8bit嵌入式微控制器的单芯片系统的设计及仿真。在单芯片内完成智能测控系统所需的数据调理、模数转换、用户按键输入、数码显示、控制量输出等功能。设计了基于FPGA的硬件仿真平台,验证了系统功能的正确性。本设计具有较强的通用性,可用于多种测控场合。     

DTN-Balance: A Forwarding-Capacity and Forwarding-Queue Aware Routing for Self-organizing DTNs

In delay-tolerant networks (DTNs), intermittent network connectivity and lack of global system information pose serious challenges to achieve effective data forwarding. Most state-of-the-art DTN routing algorithms are based on hill-climbing heuristics in order to select the best available next hop to achieve satisfactory network throughput and routing efficiency. An adverse consequence of this approach is that a small subset of good users take on most of the forwarding tasks. This can quickly deplete scarce resources (e.g. storage, battery, etc.) in heavily utilized devices which degrades the network reliability. A system with a significant amount of traffic carried by a small number of users is not robust to denial of service attacks and random failures. To overcome these deficiencies, this paper proposes a new routing algorithm, DTN-Balance, that takes the forwarding capacity and forwarding queue of the relay nodes into account to achieve a better load distribution in the network. For this, we defined a new routing metric called message forwarding utility combining nodal available bandwidth and forwarding workload. Applying small world theory, we impose an upper bound on the end-to-end hop count that results in a sharp increase in routing efficiency. Queued messages in a forwarding node are arranged by DTN-Balance based on message dropping utility metric for a more intelligent decision in the case of a message drop. The performance of our method is compared with that of the existing algorithms by simulations on real DTN traces. The results show that our algorithm provides outstanding forward efficiency at the expense of a small drop in the throughput.

     

一种面向多媒体SOC的微状态低功耗设计方法

针对目前移动多媒体SOC设计中日益突出的功耗问题,结合传统的动态功率管理和动态频率调整中的负载预测和反馈控制两种方法,同时利用系统中各类IP和设计模块的可配置特性,提出了一种基于微状态的面向多媒体应用SOC的系统级低功耗设计方法。该方法以F-ARIMA过程作为负载预测模型,以最后期限缺失率作为反馈控制信号来实现系统实时动态在微状态之间进行切换,从而尽可能使得负载能均匀分布于运行期间。该方法在保证多媒体服务质量(QOS)的同时,有效降低了系统功耗。     

Destination-driven routing for low-cost multicast

We present a destination-driven algorithm that optimizes for applications, such as group video or teleconferencing, that require multicast trees with low total cost. The destination-driven algorithm uses a greedy strategy based on shortest-path trees and minimal spanning trees but biases routes through destinations. The performance of the algorithm is analyzed through extensive simulation and compared with several Steiner tree heuristics and the popular shortest-path tree (SPT) method. The algorithm is found to produce trees with significantly lower overall cost than the SPT while maintaining reasonable per-destination performance. Its performance also compares well with other known Steiner heuristics. Moreover, the algorithm does not suffer from high complexity common to most Steiner tree heuristics and builds a route by querying only incident links for cost information     

基于压缩感知信号重构的wifi室内定位算法研究

针对位置指纹定位算法在训练阶段信号数据采集量大和定位精度不高的问题,提出一种压缩感知(CS,Compressed Sensing)与K均值改进支持向量机(SVM,Support Vector Machine)相结合的定位算法模型(CS-KSVM)。CS算法在训练阶段利用已采集到的部分参考点wifi信号强度数据对整个指纹信号库进行重构以降低信号采集工作量,再用K均值改进SVM算法来实现测试点的准确分类。实验仿真结果表明,CS-KSVM算法在相同采样点条件下的定位精度明显要高于传统定位算法,同时在相同定位精度条件下大大减少了定位需要的采样点数。CS-KSVM算法在3米之内的定位准确度可以达到93.2%。     

仿真技术在晶圆制造光刻区派工中的应用

对光刻区的派工法则进行了分析研究.在传统的先来先服务规则的基础上,根据光刻区的生产特性及实际情况,以最小化完工时间为目标,主要考虑到减少设备的调整时间,提出一种启发式综合派工法则.对某晶圆制造厂的一组光刻设备进行实例研究,运用Extend仿真软件对传统先来先服务规则和启发式综合派工法则分别建立仿真模型,通过仿真得出主要生产性能参数.结果表明,启发式综合派工法则明显优于现有的先来先服务规则.     

一种基于V／F变换的数字相敏检测方法

本文提出一种基于电压频率变换（Ｖ／Ｆ）的数字相敏检测方法。这种方法可对被检测信号进行矢量分析，文中分析了这种数字相敏检测方法在加性高斯白噪声和谐波干扰环境下的检测性能，并给出了这种方法与常用的正交采样法的计算机模拟比较结果，此外，文中还给出了本文所提出方法用微处理器实现的结构。     

PCM/FM遥测系统中用于去除多谱勒频率和载波频偏的新方法

本文首先分析了均匀采样二阶DPLL(Digital Phase-Locked Loop)误差传递函数的特性,并基于均匀采样二阶DPLL误差传递函数的高通特性提出了脉冲编码调制/调频(PCM/FM)遥测系统中用于去除多谱勒频率和载波频偏的新方法;然后给出了设计实例和相应的计算机仿真结果;最后给出了有效的实现方法。计算机仿真结果表明,基于均匀采样二阶DPLL误差传递函数的高通特性用于去除多谱勒频率和载波频偏的方法是可行的。     

Minimizing Packet Waiting Time in a Multibeam Satellite System

In this paper, we examine the problem of time-slot assignment in an SS/TDMA system operating in a packet-switched environment. We seek to assign time slots in order to minimize average packet waiting time and in order to maximize transponder utilization. We show that an assignment which achieves both objectives exists and develop a branch-and-bound algorithm to find it. In addition, we suggest several heuristics which require much less computational effort and give very close to optimal results. We derive theoretical bounds on the performance of these heuristics and perform simulation trials to show that, on average, the heuristics are very much better than their bounds suggest, and are, in fact, extremely close to optimal.     

A note on efficient SS/TDMA assignment algorithms

A time-slot assignment procedure using the maximum-weight matching algorithm is proposed and investigated. In contrast with previous methods, based on the maximum-cardinality matching, the proposed procedure allows the inclusion of known heuristics in a more direct manner. Computer simulation gives evidence of efficiency improvements by using this approach     

The fuzzy based QMPR selection for OLSR routing protocol

In this paper, a heuristics for highly efficient selection of multipoint relays (MPR) in optimized link state routing (OLSR) protocol is proposed. MPR selection is one of the most important and critical function of OLSR protocol. This paper proposes a Fuzzy logic based novel routing metric for MPR selection based on the energy, stability and buffer occupancy of the nodes. An algorithm is designed to cope with these constraints in order to find quality MPR (QMPR) that guarantees the QoS in OLSR. The aim of this paper is to formulate, build, evaluate, validate and compare rules for QMPR selection using fuzzy logic. It has been validated that proposed composite metric (based on energy, stability and buffer occupancy) selects a more stable MPR. By mathematical analysis and simulation, it is shown that efficiency of OLSR protocol has been improved using this new routing metric, in terms of energy efficiency and network life time.