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31.
针对多层微波集成电路设计的微带线层间互连问题,介绍了垂直通孔互连、垂直带条互连和层耦合过渡互连三种高性能的互连方法,并且采用三维电磁仿真软件HFSS对这三种互连结构进行了建模和仿真。仿真结果表明,垂直通孔互连和垂直带条互连在0.1~25 GHz的频宽范围内,回波损耗S11<-20 dB,插入损耗S21>-1 dB,互连性能优良,而层耦合过渡互连在20~68 GHz内回波损耗S11 <-20 dB,插入损耗S21>-1 dB,具有在毫米波频段实现互连的潜力。  相似文献   
32.
In today's tough economic environment, governments at all levels face significant budget shortfalls and public rail transit systems must compete with other public services for government subsidies. It is critical that public rail transit systems be concerned with their operational performance and efficient use of resources. In this paper, we develop a methodology that measures a rail transit system's performance relative to that of other rail transit systems, compares its performance to an appropriate efficient benchmark system, and identifies the sources of its inefficiency. We analyze the relationship between public subsidies and operational performance of public rail systems and show an inverse relationship between subsidization and efficiency.  相似文献   
33.
3S技术是测量技术发展史的一次重大突破,给测量领域带来了新的生命力,并已推广应用在国家基础建设的各个方面。本文以京沪高铁天津段这样的国家重点建设工程项目为例,介绍了3S技术在该项目从土地规划到建设运营方面的应用。  相似文献   
34.
为提高设备检维修现场管理水平,中国石化南通石油分公司大岸桥石油机械厂钳工车间将6S现场管理理念导入钳工车间日常检维修管理中,通过对检维修现状和方式的分析,创新管理理念,制定有效的计划及措施并落到实处,使钳工现场检维修管理模式得到优化,提升了车间的管理水平。  相似文献   
35.
Takeovers by telecommunications carriers have surged during between 1996 and 2005, stimulated by the Telecommunications Act of 1996. In this study, we hypothesize and test the short-term and long-term performance of telecommunications carrier mergers and acquisitions (M&As) between 1996 and 2005 according to three main categories (strategic types, bidder characteristics, and payment methods). For short-term performance, this study investigates abnormal market returns of bidding firms after M&A announcements and our study shows that telecommunications carrier M&A announcements do result in a significant increase in shareholder wealth in the short run. However, from a long-term perspective, which has been investigated in terms of the survival rate and the operating performance after M&As, the telcos experience a statistically significant decrease of up to 10%. The results also show that though strategic type, bidder characteristics, and payment method play an important role in the value creation of M&As in the short term, only the bidder size matters in the success of M&As over a long period of time.  相似文献   
36.
随着计算机网络的飞速发展,OA系统已是高校信息化建设的重要标志。本文研究了高校信息化办公现状,针对存在的问题,设计并实现了基于B/S体系结构的协同办公系统。系统实现采用了MVC模式。经测试,系统满足设计需求,运行可靠。  相似文献   
37.
This study extends the literature on modeling the volatility of housing returns to the case of condominium returns for five major U.S. metropolitan areas (Boston, Chicago, Los Angeles, New York, and San Francisco). Through the estimation of ARMA models for the respective condominium returns, we find volatility clustering of the residuals. The results from an ARMA‐TGARCH‐M model reveal the absence of asymmetry in the conditional variance. Dummy variables associated with the housing market collapse unique to each metropolitan area were statistically insignificant in the conditional variance equation, but negative and statistically significant in the mean equation. Condominium markets in Los Angeles and San Francisco exhibit the greatest persistence to volatility shocks.  相似文献   
38.
We investigate whether Article 11 pro forma financial information assists investors in valuing IPOs. While the SEC expects it to be helpful in assisting investment decisions, Article 11 pro forma financial information is based on registrants' understanding and assumptions, and registrants can exercise their own judgment when preparing pro forma financial statements. It is therefore an empirical question whether the information contained in pro forma financial statements is useful to investors. We examine the association between pro forma adjustments of earnings and book value of equity and the IPO offer value and find asymmetric results. While positive pro forma adjustments of earnings and book value of equity are positively associated with the IPO offer value, negative pro forma adjustments of earnings and book value of equity are negatively associated with the IPO offer value, suggesting that negative pro forma adjustments are priced as growth opportunities. Additional analyses reveal that the association between pro forma adjustments of book value of equity and the IPO offer value varies across different time periods and industries and that pro forma adjustments of book value of equity are initially mispriced by investors. In contrast, we do not find similar results for pro forma adjustments of earnings. Further empirical tests show that the asymmetric results of mispricing of pro forma adjustments of earnings and book value of equity may be explained by the requirements of Article 11 of Regulation S‐X for pro forma adjustments dictating that adjustments to earnings reflect only recurring items while adjustments to book value reflect both recurring and nonrecurring items.  相似文献   
39.
通过对民营企业采用5S管理为例,阐述了现场管理是企业生产管理的一项基础性管理工作。5S管理是一种较为先进科学的管理方法,要深刻认识5S管理的重要性,并应用于企业管理的实践中。通过对企业员工日常行为的规范,提升企业整体的现场管理水平,从而提高企业的竞争力。  相似文献   
40.
We investigate how new information impacts quote clustering in the bond market. We find that clustering, along with quote activity, price volatility and bid-ask spreads, increases sharply in the minutes following releases of macroeconomic news. Each returns to near-normal levels within the hour. Effects are strongest for more liquid on-the-run notes and for the announcements typically associated with substantial information flow. The strong positive comovement of clustering, quote activity, price volatility, and bid-ask spreads supports the conclusion that innovations of these variables are endogenous to the arrival and incorporation of information into prices.  相似文献   
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