Quantitative Evaluation of Register Pressure on Software Pipelined Loops

Software Pipelining is a loop scheduling technique that extracts loop parallelism by overlapping the execution of several consecutive iterations. One of the drawbacks of software pipelining is its high register requirements, which increase with the number of functional units and their degree of pipelining. This paper analyzes the register requirements of software pipelined loops. It also evaluates the effects on performance of the addition of spill code. Spill code is needed when the number of registers required by the software pipelined loop is larger than the number of registers of the target machine. This spill code increases memory traffic and can reduce performance. Finally, compilers can apply transformations in order to reduce the number of memory accesses and increase functional unit utilization. The paper also evaluates the negative effect on register requirements that some of these transformations might produce on loops.     

一种内调焦对心器用电视测微镜头的设计

利用CODE V光学软件设计了一种用于内调焦对心器的电视测微镜头。该镜头由四片透镜组成,采用正负正焦距对称结构。其焦距为17.20 mm,数值孔径为0.063,视场为16.82°。该镜头工作在486～656 nm波段,总长为68 mm。系统的全视场畸变为-1.13%,调制传递函数MTF值在空间频率为60 lp/mm时大于0.64。设计结果表明,该系统的成像质量良好,结构紧凑,满足使用要求。     

国产CODECASE2115小口径管焊接接头性能研究

依据国产CODECASE2115小口径管材的成分和性能,合理选择了焊接材料和焊接工艺,并对焊接接头进行试验与分析,验证了可以获得合格焊接接头的相应的焊接材料和焊接工艺,实现了超超临界锅炉中耐热钢管国产化材料的焊接工艺,扩大了耐热钢管及焊接材料的供货方范围,且国产的CODECASE2115奥氏体钢管与国外同类材料相比,价格与供货期都更有优势,也为这种材料在超超临界机组中的应用积累了试验数据。     

Visual Mark for Robot Manipulation and Its RT-Middleware Component

In this paper, a visual marker called Coded Landmark for Ubiquitous Environment (CLUE) is proposed for easy robot manipulation using the RT-middleware component technology. Currently, home service robots are being expected to work in human living environments; however, such environments might be highly complex for robots. One of the solutions to solve such problems might be the development of structured environments for robots, such as visual marks in human living space, which could often be used in industrial fields, e.g., marked lines for mobile robots in industry. For application of structured environments from the factory to the human living environment, the affinity to humans might be important, such as marks invisible to humans, but visible to robots. In this paper, an invisible marker, CLUE, which is based on QR codes, is proposed; this will provide robots with information on the objects that are to be manipulated and visual guidance required for robot manipulation based on the RT-middleware platform. Finally, by means of actual robot applications, the method to use the proposed robot technology component is shown.     

CONTROL STRATEGY FOR ELECTRO-HYDRAULIC POSITION SERVO SYSTEM WITH GENERALIZED PULSE CODE MODULATION

A hybrid control strategy has been designed and developed for the electro-hydraulic posi-tion servo control system with generalized Pulse code modulation (GPCM), which is suitable for the area where the work condition is poor and a large flow rate is required. It is difficult to control the GPCM system because the system is discrete. With consideration of the stability and speediness of the GPCM position servo control system, a control strategy is developed through the theoretical and ex-perimental analyses. The control strategy integrates the merits of Bang-Bang control, PID control and fuzzy control. With this hybrid control strategy, the electro hydraulic control system has good per-formances, and the servo control is carried out with GPCM through on-off valves.     

Group Based Common-Receiver/DS CDMA Wireless Networks And (GBCR) Code Protocol for Its Performance Study

A spreading code protocol (GBCR protocol)suitable for DS CDMA wireless data networks is proposedin this paper. The network is co-ordinated by a centralstation (CS) which maintains a database tracking each user's status. Users are divided intogroups, each of which is assigned a group-basedcommon (GBC) code used by a transmitter in thegroup to acquire the current state of its target. Data communication is allowed only after apositive ACK packet from the CS is received by thetransmitter, so that all successful terminals aresheltered by the CS from possible third-partyinterference which may use the same receiver-based code.Analytical results reveal that the GBCR protocol caneffectively improve network stability andthroughput-delay performance.     

Natural convection/radiation heat transfer simulations of enclosed array of vertical rods

Abstract

Experiments performed by Arya and Keyhani (1990) measured the temperature of 12 vertical heated rods within a constant temperature, internally finned cylindrical enclosure. Measurements were performed with air and helium in the enclosure for ranges of rod heat generation rate and gas pressure. In the current work, steady three-dimensional computational fluid dynamics simulations of conduction, natural convection and radiation heat transfer within the experiment were conducted to benchmark the simulation techniques. In the computational model, different thermal conductivities were applied to a spacer plate between a plate that held the heaters, and one of the enclosure endplates. This was done to model a range of contact resistance between the plates. This was necessary because the experimental endplate conditions were not completely documented. The calculations accurately reproduced the local and average temperatures when a high contact resistance was modelled. These results emphasise that conditions far from data measurement locations can affect experimental results. Those conditions must be well documented if they are to be used to benchmark computational methods.     

基于OTA技术实现USIM卡动态更新菜单

3G网络下的USIM卡利用OTA技术,让OTA服务器以数据短消息的形式将相应的OTA下载数据透明地传送给卡,对卡内的数据与菜单进行更新。在USIM卡COS(卡片操作系统)基础上,提出一个三层应用结构模型,阐述了业务菜单数据在卡内如何组织形成并且动态更新。对于菜单数据在COS中如何有效的存储和读取,自定义了一套以C语言实现的字节编码规则。该研究结果已经成功应用到卡的芯片中,有效解决USIM卡中的应用和服务主动与手机终端进行交互操作的问题。     

单片机实现遥控器键盘功能接口及应用

在介绍红外遥控器原理的前提下,深入研究了PS2键盘鼠标协议的工作原理和实现过程.重点给出了红外遥控键盘收发系统是如何实现的,包括红外遥控器与P87LPC764单片机的硬件接口电路和接口软件模块实现遥控键盘的编程方法,该设计适用于各种电子产品.     

半自动弯针机的设计与实现——用于悬臂式环氧树脂探针卡的制造

首先介绍了在半导体芯片制造中,环氧树脂探针卡的作用及其制作工艺.基于探针的弯曲需严格符合一定的设计规格,阐述了半自动弯针机的设计,详细说明基于MicroLynx控制器对步进电机的控制,实现对探针的针尖长度及弯曲角度的精确控制.该项技术已应用于探针卡的实际生产中.