A user-space device driver can do many of the things that kernel drivers can t, such as perform a long-running computation, block while waiting for an event, or read files from the file system. Unlike kernel drivers, a user-space device driver can use other device drivers--that is, access the network, talk to a serial port, get interactive input from the user, pop up GUI windows, or read from disks. User-space drivers implemented using FUSD can be much easier to debug it is impossible for them to crash the machine, are easily traceable using tools such as gdb, and can be killed and restarted without rebooting even if they become corrupted. FUSD drivers don t have to be in C--Perl, Python, or any other language that knows how to read from and write to a file descriptor can work with FUSD. User-space drivers can be swapped out, whereas kernel drivers lock physical memory.
標簽:
user-space
can
drivers
perform
上傳時間:
2014-01-01
上傳用戶:saharawalker
模擬退火算法的基本思想是從一給定解開始,從鄰域中隨機產(chǎn)生另一個解,接受Metropolis準則允許目標函數(shù)在有限范圍內變壞,它由一控制參數(shù)t決定,其作用類似于物理過程中的溫度T,對于控制參數(shù)的每一取值,算法持續(xù)進行“產(chǎn)生—判斷—接受或舍去”的迭代過程,對應著固體在某一恒定溫度下的趨于熱平衡的過程,當控制參數(shù)逐漸減小并趨于0時,系統(tǒng)越來越趨于平衡態(tài),最后系統(tǒng)狀態(tài)對應于優(yōu)化問題的全局最優(yōu)解,該過程也稱為冷卻過程,由于固體退火必須緩慢降溫,才能使固體在每一溫度下都達到熱平衡,最終趨于平衡狀態(tài),因此控制參數(shù)t經(jīng)緩慢衰減,才能確保模擬退火算法最終優(yōu)化問題的整體最優(yōu)解。
標簽:
Metropolis
控制
參數(shù)
模擬退火算法
上傳時間:
2013-12-25
上傳用戶:cmc_68289287