概述
DDR （Double Data Rate）DRAM由于性能和价格的优势，正日益广泛的应用于计算机平台以及各种嵌入式产品设计中。DDR规范从DDR1，DDR2发展到DDR3，并且也发展出主要应用于移动设备领域的LPDDR（低功耗DDR）。随着总线速度的提高...概述
DDR （Double Data Rate）DRAM由于性能和价格的优势，正日益广泛的应用于计算机平台以及各种嵌入式产品设计中。DDR规范从DDR1，DDR2发展到DDR3，并且也发展出主要应用于移动设备领域的LPDDR（低功耗DDR）。随着总线速度的提高，信号完整性问题，互操作问题越来越被设计和测试人员关注。而由于DDR总线复杂度高，探测困难，测试和分析也有非常大挑战。展开更多
Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there have been various kinds of methods for vehicle traveling time prediction. But few consider bot...Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there have been various kinds of methods for vehicle traveling time prediction. But few consider both aspects of time and space. In this paper, a vehicle traveling time prediction method based on grey theory （GT） and linear regression analysis （LRA） is presented. In aspects of time, we use the history data sequence of bus speed on a certain road to predict the future bus speed on that road by GT. And in aspects of space, we calculate the traffic affecting factors between various roads by LRA. Using these factors we can predict the vehicle＇s speed at the lower road if the vehicle＇s speed at the current road is known. Finally we use time factor and space factor as the weighting factors of the two results predicted by GT and LRA respectively to find the final result, thus calculating the vehicle＇s traveling time. The method also considers such factors as dwell time, thus making the prediction more accurate.展开更多
1928年,一代围棋大师吴清源东渡日本,经过艰苦磨砺之后,以十番期为舞台,将所有对手——击败,成为“昭和围棋之王”。十番棋这种形式,对于失败者来说,几乎等于被长期钉在了耻辱柱上,正是因为其残酷性,吴先生才会庆幸今日的棋手不必再去...1928年,一代围棋大师吴清源东渡日本,经过艰苦磨砺之后,以十番期为舞台,将所有对手——击败,成为“昭和围棋之王”。十番棋这种形式,对于失败者来说,几乎等于被长期钉在了耻辱柱上,正是因为其残酷性,吴先生才会庆幸今日的棋手不必再去面对这种噩梦。1998年的 IT 行业,CPU、显示卡和主板是竞争最激烈的三个领域,主板之争其实可归结为总线速度及超顿能力之争,而这其中起决定性作用的,就是主板芯片组。展开更多
文摘概述
DDR （Double Data Rate）DRAM由于性能和价格的优势，正日益广泛的应用于计算机平台以及各种嵌入式产品设计中。DDR规范从DDR1，DDR2发展到DDR3，并且也发展出主要应用于移动设备领域的LPDDR（低功耗DDR）。随着总线速度的提高，信号完整性问题，互操作问题越来越被设计和测试人员关注。而由于DDR总线复杂度高，探测困难，测试和分析也有非常大挑战。
基金the National Natural Science Foundation of China (No. 50575145)the National High Technology Research and Development Program (863) of China(Nos. 2006AA04Z432 and 2007AA04Z419)
文摘Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there have been various kinds of methods for vehicle traveling time prediction. But few consider both aspects of time and space. In this paper, a vehicle traveling time prediction method based on grey theory （GT） and linear regression analysis （LRA） is presented. In aspects of time, we use the history data sequence of bus speed on a certain road to predict the future bus speed on that road by GT. And in aspects of space, we calculate the traffic affecting factors between various roads by LRA. Using these factors we can predict the vehicle＇s speed at the lower road if the vehicle＇s speed at the current road is known. Finally we use time factor and space factor as the weighting factors of the two results predicted by GT and LRA respectively to find the final result, thus calculating the vehicle＇s traveling time. The method also considers such factors as dwell time, thus making the prediction more accurate.
文摘1928年,一代围棋大师吴清源东渡日本,经过艰苦磨砺之后,以十番期为舞台,将所有对手——击败,成为“昭和围棋之王”。十番棋这种形式,对于失败者来说,几乎等于被长期钉在了耻辱柱上,正是因为其残酷性,吴先生才会庆幸今日的棋手不必再去面对这种噩梦。1998年的 IT 行业,CPU、显示卡和主板是竞争最激烈的三个领域,主板之争其实可归结为总线速度及超顿能力之争,而这其中起决定性作用的,就是主板芯片组。
