For many years prior to the 1970s, engineers designed and built switch mode power supplies (SMPSs) using methods based largely on intuitive and exper- imentally derived techniques. In general, these power supplies were able to achieve their primary goal of high-efficiency power conversion; unfortu- nately, due to the lack of adequate theoretical analysis techniques, many of these power supplies only marginally met their desired performance require- ments. In many cases, they were considered to be unreliable.
标签： Supplies Switch Power Mode
上传时间： 2020-06-07
上传用户：shancjb
Radio frequency identifi cation (RFID) technology is a wireless communication technology that enables users to uniquely identify tagged objects or people. RFID is rapidly becoming a cost-effective technology. This is in large part due to the efforts of Wal-Mart and the Department of Defense (DoD) to incorporate RFID technology into their supply chains. In 2003, with the aim of enabling pallet-level tracking of inventory, Wal-Mart issued an RFID mandate requiring its top suppliers to begin tagging pallets and cases, with Electronic Product Code (EPC) labels. The DoD quickly followed suit and issued the same mandate to its top 100 suppliers. This drive to incorporate RFID technology into their supply chains is motivated by the increased ship- ping, receiving and stocking effi ciency and the decreased costs of labor, storage, and product loss that pallet-level visibility of inventory can offer.
标签： A_Guide_to_Radio_Frequency_IDenti fication RFID
上传时间： 2020-06-08
上传用户：shancjb
To a quantum mechanic the whole universe is one godawful big interacting wavefunction ? but to the rest of us, it’s a world full of separate and distinguishable objects that hurt us when we kick them. At a few months of age, human children recognize objects, expect them to be permanent and move continuously, and display surprise when they aren’t or don’t. We associate visual, tactile, and in some cases audible and olfactory sensations with identifiable physical things. We’re hardwired to understand our environment as being composed of separable things with specific properties and locations. We understand the world in terms of what was where when.
上传时间： 2020-06-08
上传用户：shancjb
The basic topic of this book is solving problems from system and control theory using convex optimization. We show that a wide variety of problems arising in system and control theory can be reduced to a handful of standard convex and quasiconvex optimization problems that involve matrix inequalities. For a few special cases there are “analytic solutions” to these problems, but our main point is that they can be solved numerically in all cases. These standard problems can be solved in polynomial- time (by, e.g., the ellipsoid algorithm of Shor, Nemirovskii, and Yudin), and so are tractable, at least in a theoretical sense. Recently developed interior-point methods for these standard problems have been found to be extremely efficient in practice. Therefore, we consider the original problems from system and control theory as solved.
标签： Linear_Matrix_Inequalities_in_Sys tem
上传时间： 2020-06-10
上传用户：shancjb
This introductory chapter is devoted to reviewing the fundamental ideas of control from a multivariable point of view. In some cases, the mathematics and operations on systems (modelling, pole placement, etc.), as previously treated in introductory courses and textbooks, convey to the readers an un- realistic image of systems engineering. The simplifying assumptions, simple examples and “perfect” model set-up usually used in these scenarios present the control problem as a pure mathematical problem, sometimes losing the physical meaning of the involved concepts and operations. We try to empha- sise the engineering implication of some of these concepts and, before entering into a detailed treatment of the different topics, a general qualitative overview is provided in this chapter.
标签： MultivariableControlSystems
上传时间： 2020-06-10
上传用户：shancjb
