江阴市高级中学体育馆扩声系统工程

介绍了江阴市高级中学新体育馆主要建声设计技术指标,阐述了声学系统的设计思路,对体育馆扩声系统的组成、设备的选择以及声场布置作了分析。给出了扩声系统的测试结果,对声学特性指标实际测量结果与EASE建模结果进行了比较。该工程方案可供从事体育场馆建设和扩声系统设计者参考。     

《本期重点导读》

正本期【声频工程】栏目刊登了丁雷有关"江阴市高级中学体育馆扩声系统工程"的文章,介绍了江阴市高级中学新体育馆主要建声设计技术指标,阐述了声学系统的设计思路,对体育馆扩声系统的组成、设备的选择以及声场布置作了分析。给出了扩声系统的测试结果,对声学特性指标实际测量结果与EASE建模结果进行了比较。该工程方案可供从事体育场馆建设和扩声系统设计者参考。【电声基础】栏目刊登了纪     

基于语言清晰度的体育馆声学工程——以江阴市体育馆为例

以江阴市体育馆为例，论述了语言清晰度的理论设计依据与实现方法，介绍了该馆声学工程中的建声设计和电声设计，对声学特性指标实际测量结果与EASE建模技术结果进行了比较。该工程方案可供从事体育场馆建设和扩声系统设计者参考。     

指挥调度大厅的扩声系统研究

为了获得良好的扩声质量,把组成扩声系统的各个部分作为一个整体来处理。介绍了扩声系统原理和系统声学特性,从扩声系统稳定性设计,扬声器、扩音机、音柱等部件的设计与配置等方面进行总结,在实际工作中对改善扩声系统的整体效能有一定的价值。     

微机技术在厅堂音质控制中的应用

使用声学ＣＡＤ系统软件，对厅堂建声特性和扩声系统声学特性进行设计计算，以达到控制厅堂音质的目的。     

北京剧院音响系统简介

本文简要介绍了北京第十一届亚运会配套新建工程项目——北京剧院的观众厅扩声系统、立体声电影还音系统、卡拉OK歌舞厅扩声系统和公共区背景音乐系统之构成以及扩声系统声学特性实测结果。     

有关歌舞厅声学设计的几个问题

有关歌舞厅声学设计的几个问题建设部建筑设计院曹孝振中华人民共和国文化部颁布了两个行业标准——“歌舞厅扩声系统的声学特性指标与测量方法”（ＷＨ０１－９３），“歌舞厅照明及光污染限定标准“（ＷＨ０２０１－９４），作为歌舞厅分级管理的强制性法规，并据此对歌...     

某企业多功能厅扩音系统的设计及调试

以某企业多功能厅的扩声系统设计为例,对多功能厅扩声系统的设计指标、Bose Modeler(R)软件作为扩声系统计算机辅助设计与分析的方法、扬声器的选型及布置、关键设备选型、系统调试等过程进行了阐述,并针对企业多功能厅扩声系统的系统结构及设备选型进行了分析与探讨.     

体育馆声学设计的实质——语言清晰度设计

指明了体育馆声学设计主要是建声系统和扩声系统的语言清晰度设计.从体育馆建声设计标准和体育馆扩声系统指标要求进行论述.引用奥组委对最大声压级的具体要求.     

江阴市体育中心体育场扩声系统设计

阐述了江阴市体育中心体育场扩声系统的设计理念,介绍了体育场扩声系统的组成、扩声设备的选择、主扩声系统扬声器的布置方式等,说明了该体育场扩声系统设计的难点及解决措施.利用EASE4.0声学设计软件对该体育场扩声系统进行了辅助设计,经EASE4.0模拟测试结果证明,当系统同时正常工作时,完全达到项目的有关要求和设计指标,并...     

Examining International Country-to-Country Flow of Theatrical Films

The present study examined the country-to-country flow of theatrical films. We hypothesize that a country's level of film imports is influenced by the domestic cinema market size of the exporter, and cultural and linguistic ties between the 2 countries. Regression models tested a dataset drawn from UNESCO's data on annual film imports from major cinema-exporting markets. Results revealed that trade traffic rises with exporters' and importers' home cinema economies, but is lessened by cultural distance between them. The test of the interactional effect of market size and cultural distance, however, reveals that the film flow's cultural discount was significantly moderated by the exporter's market size, which advances the literature. Finally, the flow escalates when both sides speak a common language.     

The Economics of the Television Market for Theatrical Movies

The new bargaining strategy of network bidding for feature films before their theatrical release is a logical extension of the networks' activities in the regular TV programming market.     

ADC性能及其对接收机性能的影响

对模-数变换器(ADC)的性能及其对数字接收机性能的影响进行了讨论,其中详细论述了如何根据输入带宽决定ADC的最高采样频率、如何根据数字接收机的动态范围选取ADC的位数以及ADC的虚假响应和噪声对数字接收机的动态和灵敏度的影响,从而指出数字接收机的性能不可能超过所采用的ADC的性能。因此,要提高数字接收机的性能首先要保证ADC的性能。     

设备性能

Rogers与许多电缆经营者一样,采取了升级方式,而不是全部重建。因为重建就要铺设许多新电缆,造价太高。公司决定建一个最多由10个干线放大器和3个线路延伸器级组成的600MHz双向设施,利用反向桥式切换开关把反向路径隔成每50～100户为一个馈送区。     

Performance engineering

Failure caused by poor performance renders a system just as useless as failure caused by functional errors, and can be even more expensive to correct. For many years, performance in software systems has been achieved through a fix-it-later approach, using optimisation and tuning techniques. Recent evidence shows that, with the increased use of highly complex, multi-layered, client/server, distributed architectures, these techniques cannot be relied on to deliver even the level of performance required during early operation when workloads are small, let alone over extended periods. This paper describes some of the ways in which performance can be engineered into systems — examples of how these techniques have been used in recent BT projects are included.     

绩效管理促企业文化变革是中小企业首选

如果说是什么对当前中国民营企业的发展影响最大？那就是企业文化。从概念上来说，企业文化是指在一定的社会历史条件下，企业在生产经营和管理活动中所创造出来的具有本企业特色的精神财富。包括文化观念、价值观念、企业精神、道德规范、行为准则、历史传统、文化环境等。企业文化这个词对于中国的中小企业来说是既熟悉，而又陌生的。说熟悉，是因为每个企业老板动辄都在拿企业文化说事儿；     

Fab Performance

To remain competitive and to boost profitability, manufacturers in capital-intensive and highly competitive industries want to maximize throughput and minimize flow time. Achieving high throughput conflicts with achieving low flow time. In order to unhide the tradeoff between throughput and flow time, a performance measure, called manufacturing performance, has been developed. The manufacturing performance is defined by the quotient of the ratio between throughput and flow time of an actual manufacturing system and this ratio of a reference system. The reference system can be adapted by the user in correspondence with objectives. By applying the manufacturing performance to one workstation and using analytic approximations for this workstation, manufacturing performance can be expressed analytically. It seems that manufacturing performance has an optimal value that is given by equipment availability and coefficient of variation. Manufacturing performance is applied also to a four-workstation manufacturing line. Results from analytic approximations show the practicability of the manufacturing performance. Comparison of manufacturing performance with overall fab efficiency, an earlier proposed metric, showed that the manufacturing performance is a more clear metric. This conclusion was based upon simulations with a two-stations manufacturing line. The manufacturing performance is a technical performance metric for manufacturing lines that supports, for instance, economical considerations to obtain optimal throughput-flow time combinations under economical optimal results. This is a useful addition to the existing metrics, which may benefit manufacturers in their operations. The authors consider this contribution as a discussion paper and demand for comment.     

Performance Modelling

Performance modelling is arguably the most subtle and sophisticated form of modelling employed as a matter of routine in the telecommunications industry. While most other techniques are aimed at deriving the basic consequences of different scenarios, performance models are targeted at crucial second-order effects, at interactions, or at mechanisms for their control. This paper discusses the techniques used for this, and illustrates these by some case studies drawn from a range of different analyses.     

高性能并行集群的性能测试与优化研究

以IBM BladeCenter高性能集群系统性能测试为背景,研究大规模集群的性能测试与优化方法.通过对基于区域分解大规模线性方程组中并行求解算法在4个测试方案下的测试和分析,得到了其加速性能随计算节点数的变化曲线.结果表明,该高性能计算机集群具有很好的加速性能、稳定性,达到了预期的测试目标,为基于该并行平台的进一步并行开发研究奠定了基础.     

Performance of Reduced-Rank Equalization

We evaluate the performance of reduced-rank equalizers for both single-input single-output (SISO) and multiple-input multiple-output (MIMO) frequency-selective channels. Each equalizer filter is constrained to lie in a Krylov subspace, and can be implemented as a reduced-rank multistage Wiener filter (MSWF). Both reduced-rank linear and decision-feedback equalizers (DFEs) are considered. Our results are asymptotic as the filter length goes to infinity. For SISO channels, the output mean-squared error (MSE) is expressed in terms of the moments of the channel spectrum. For MIMO channels, both successive and parallel interference cancellation are considered. The asymptotic performance in that case requires the computation of moments, which depend on shifted versions of the channel impulse response for different users. Those are also expressed in terms of the MIMO channel frequency response. Numerical results are presented, which show that near full-rank performance can be achieved with relatively low-rank equalizers