超通用水分子形交換方塊之FPGA設計
本研究提出一個新的超通用、每邊w個端點的四邊形水分子形交換方塊(Water-Molecule-Shaped Switch Block; WMSB)架構,以應用在FPGA之多點連線(multipoint interconnection)和諸多交換網路的設計上。超通用交換方塊(HUSB)的領域中,Fan[2]提出當前唯一一個(4, w)-HUSB,但Fan’s (4, w)-HUSB所需的開關個數大約是6.3w個開關,在接下來的篇幅之中,我們將證明(4, w)-WMSB是只需6w個開關的HUSB;此外,我們還證明沒有(4, w)-HUSB可以使用小於6w個開關。本研究中還使用VPR(一種CAD)及其內建的大量標準線路以證明(4, w)-WMSB不僅是理論上最佳的亦是實用性佳的交換方塊。鑑此,(4, w)-WMSB開關效率高(switch-efficiency)的設計十分適用於其他的交換網路設計,如公共電話網路(Public Switched Telephone Network)。
The Effect of Hands Free - Cell Phone Conversation on Visual Fields
It is a known fact that using a cell phone while driving can lead to reckless driving. According to research done by the World Health Organisation (2011) thousands of car accidents occur worldwide, each day, due to cell phone use whilst driving. Many of these car accidents result in serious injury or death of drivers, passengers or pedestrians. According to the Automobile Association (2012), cell phones are the number one cause of traffic accidents in South Africa. The high rate of car accidents due to cell phone use has led to legislation being passed, in most countries, banning hand-held cell phone use while driving. Hands-free phone equipment is not prohibited as it is widely regarded as a safe means of making and taking a phone call while behind the wheel. The purpose of this study was to show that the act of talking on a cell phone and not the method of talking (hand-held versus hands-free) increases accident probability. This study used a Friedman Visual field analyser which measures subject’s visual fields with and without engaging in hands-free cellular conversation. The results showed a significant constriction of the visual fields when subjects were conversing on a cell phone. These results were and can be explained by the fact that the test subject experiences cognitive distraction. Cognitive distraction occurs because the driver has to divide his/her attention between the cell phone conversation and the tasks relating to driving. These results have significant ramifications for road safety in a driving environment.