Once upon a time, cellular wireless networks provided two basic services: voice
telephony and low-rate text messaging. Users in the network were separated
by orthogonal multiple access schemes, and cells by generous frequency reuse
patterns [1]. Since then, the proliferation of wireless services, fierce competition,
andthe emergenceof new service classes such as wireless data and multimediahave
resulted in an ever increasing pressure on network operators to use resources in a
moreefficient manner.In the contextof wireless networks,two of the most common
resources are power and spectrum—and, due to regulations, these resources are
typically scarce. Hence, in contrast to wired networks, overprovisioning is not
feasible in wireless networks.
標簽：
Maximization
Nonconvex
Wireless
Utility
Systems
in
上傳時間：
2020-06-01
上傳用戶：shancjb
For more than a century, overhead lines have been the most commonly used
technology for transmitting electrical energy at all voltage levels, especially on the
highest levels. However, in recent years, an increase in both the number and length
of HVAC cables in the transmission networks of different countries like Denmark,
Japan or United Kingdom has been observed. At the same time, the construction of
offshore wind farms, which are typically connected to the shore through HVAC
cables, increased exponentially.
標簽：
Electromagnetic
Transients
Cables
Power
in
上傳時間：
2020-06-07
上傳用戶：shancjb
Thepredecessorvolumeofthisbookwaspublishedin1996.Intheyears
since then, some things have changed and some have not.
Two of the things that have not changed are the desire for better
models and faster simulations. I performed the original simulations on
my “hyperfast” 133-MHz computer! At the time, I thought if I could just
getafastercomputer,allofourSPICEproblemswouldbehistory,right?
TodayIamsimulatingonacomputerthathasa2.6-GHzprocessorwith
512 MB of RAM, and I would still say that simulations run too slow.
The computer technology has evolved, but so have the models. In 1996
wewereperformingsimulationson100-kHzpowerconverters,whereas
today I routinely see 1- and 2-MHz power converters.
標簽：
Switch-Mode
Simulation
Supply
Power
上傳時間：
2020-06-07
上傳用戶：shancjb
