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1.
设计和实现了一种新的分组调度机制,可以根据网络服务和应用的要求配置不同的策略。分析了分组调度机制的总体框架以及涉及的关键技术,详细讨论了流分类、排队、分组准入控制、分组丢弃和调度5个模块的设计和实现,同时对分组调度机制的性能进行了分析和测量,并对结果进行了讨论。  相似文献   

2.
CAPP系统自动分组的实现   总被引:1,自引:0,他引:1  
对零件分组是实施计算机辅助工艺过程设计的首要任务。本文结合SJCAPP系统的研制开发,介绍了计算机对零件自动分组的实现、软件设计技巧,并就提高分组速度,保证分组准确无误等进行了探讨。  相似文献   

3.
文章在对传统毕业设计分组弊端剖析的基础上,提出了基于模糊评估的毕业设计分组法。以港工专业为例,建立了毕业生成绩评定指标体系,并通过非结构性决策模糊集分析单元系统理论确定各指标权重,采用模糊评估法进行成绩综合评定,在毕业设计中按成绩优劣对学生合理搭配,科学分组,从而更好的实现毕业设计目的。  相似文献   

4.
在分组间插的OTDM局域网中,光分组的发送和接收不仅受限于电子处理速度的限制,而且受限于光分组压缩解压缩器的结构。本文提出了使用分组重排和光时分解复用器构建并行解压缩器来缓解该受限问题的方案。同时,通过对传统的周期预留多址接入CRMA(Cycle Reservation Multiple Access)协议进行进一步扩展,得到了在受限条件下既能避免将数据分组简单丢弃、又能获取很高网络性能可行的高速网络接入控制协议。  相似文献   

5.
张宇  胡晓光  姜红  陈敏璠  莫修浩 《包装工程》2023,44(21):279-285
目的 研究一种红外光谱法与化学计量学相结合的方法,以对现场提取的快递包装纸盒样品进行快速检验分类。方法 利用红外光谱法对53个快递包装纸盒样品进行检验,依据其主要填料差异进行分类,并利用系统聚类进行分组。基于该分组,训练随机森林模型、多层感知器判别、Fisher判别3种预测模型,实现对新样品组别的分类预测。结果 53个快递包装纸盒样品被分为3类,而后进一步细分为9组,训练得到的3种判别模型中的Fisher判别预测准确率较高。结论 该检验方法快速、无损、准确,依据化学计量学实现对快递包装纸盒样品的快速检验,为公安机关检验此类物证提供依据。  相似文献   

6.
从预报水下结构声辐射的Helmholtz边界积分方程出发,基于壳体上数量有限的振动传感器,提出了壳体表面振速分组测量的声辐射预报方法。专门设计了一个多舱段复杂壳体模型,分别进行了单台设备激励、多台设备激励的壳体振动与声辐射试验。对比分析结果表明,该分组预报方法是准确的、可行的,最后还对表面振动分组的原则进行了讨论。  相似文献   

7.
自动识别典型零件的成组双向联想记忆法   总被引:1,自引:0,他引:1  
成组双向联想记忆法是利用BAM网络对零件进行分组的方法,它的提出使零件分组走向了智能化。但使用成组双向联想记忆法分组时,必须事先给出每个零件组的“典型零件”供BAM网络学习,实际工作中要满足这一条件有时是困难的。为此,本文提出了一种能自动识别典型零件的成组双向联想记忆法。该方法具有自组织、自适应、学习和联想记忆的功能,能一边学习一边自动识别出典型零件并分组,是一种智能分组方法。  相似文献   

8.
一种能处理无线链路拥塞的TCP/ARQ改进算法   总被引:3,自引:0,他引:3  
采用链路层自动请求重传(ARQ)方法来对分组差错进行恢复,并对传统的TCP/ARQ算法加以改进,加入了在无线链路拥塞情况下的自适应拥塞避免算法。仿真结果表明,这种能处理无线链路拥塞的TCP/ARQ算法对于提高无线网络的吞吐量非常有效。  相似文献   

9.
本文主要介绍了分组传输网络PTN的实现协议与关键技术,并对其应用优势进行了探讨,以供大家参考。  相似文献   

10.
本文提出了一种利用纯相位型液晶空间光调制器(LC-SLM)实现相息图三维显示的方法.该方法以LC-SLM为显示器件,通过相息图的衍射进行三维像的重构.详细研究了相息图的计算及其与LC-SLM参数间的关系,并对再现像像质进行了讨论.为提高显示的空问分辨率,采用分时复用技术,对三维物体进行分组取样,并计算每一分组的相息图,形成分组相息图序列,再现时依次将相息图输入到LC-SLM,利用人眼的视觉残留效应以达到连续扫描三维成像的目的.实验结果表明,该方法实现了三维物体的再现,为三维显示提供了一种有效的方法.  相似文献   

11.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

12.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

13.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

14.
We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.  相似文献   

15.
Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.  相似文献   

16.
ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.  相似文献   

17.
As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.  相似文献   

18.
Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.  相似文献   

19.
TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.  相似文献   

20.
The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.  相似文献   

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