We show in the context of a new economic geography model that when labor is heterogenous trade liberalization may lead to industrial agglomeration and inter-regional trade. Labor heterogeneity gives local monopoly power to firms but also introduces variations in the quality of the job match. Matches are likely to be better when there are more firms and workers in the local market, giving rise to an agglomeration force which can offset the forces against, trade costs and the erosion of monopoly power. We derive analytically a robust agglomeration equilibrium and illustrate its properties with numerical simulations
标签： 经济、城市化和经济增长
上传时间： 2016-04-02
上传用户：kinda233
The TAS3204 is a highly-integrated audio system-on-chip (SOC) consisting of a fully-programmable, 48-bit digital audio processor, a 3:1 stereo analog input MUX, four ADCs, four DACs, and other analog functionality. The TAS3204 is programmable with the graphical PurePath Studio™ suite of DSP code development software. PurePath Studio is a highly intuitive, drag-and-drop environment that minimizes software development effort while allowing the end user to utilize the power and flexibility of the TAS3204’s digital audio processing core. TAS3204 processing capability includes speaker equalization and crossover, volume/bass/treble control, signal mixing/MUXing/splitting, delay compensation, dynamic range compression, and many other basic audio functions. Audio functions such as matrix decoding, stereo widening, surround sound virtualization and psychoacoustic bass boost are also available with either third-party or TI royalty-free algorithms. The TAS3204 contains a custom-designed, fully-programmable 135-MHz, 48-bit digital audio processor. A 76-bit accumulator ensures that the high precision necessary for quality digital audio is maintained during arithmetic operations. Four differential 102 dB DNR ADCs and four differential 105 dB DNR DACs ensure that high quality audio is maintained through the whole signal chain as well as increasing robustness against noise sources such as TDMA interference. The TAS3204 is composed of eight functional blocks: Clocking System Digital Audio Interface Analog Audio Interface Power supply Clocks, digital PLL I2C control interface 8051 MCUcontroller Audio DSP – digital audio processing 特性 Digital Audio Processor Fully Programmable With the Graphical, Drag-and-Drop PurePath Studio™ Software Development Environment 135-MHz Operation 48-Bit Data Path With 76-Bit Accumulator Hardware Single-Cycle Multiplier (28 × 48)
上传时间： 2016-05-06
上传用户：fagong
Description The L9352B is an integrated quad low-side power switch to drive inductive loads like valves used in ABS systems. Two of the four channels are current regulators with current range from 0 mA to 2.25 A. All channels are protected against fail functions. They are monitored by a status output.
标签： L9352B
上传时间： 2019-03-27
上传用户：guaixiaolong
The AZ1117 is a series of low dropout three-terminal regulators with a dropout of 1.15V at 1A output current. The AZ1117 series provides current limiting and thermal shutdown. Its circuit includes a trimmed bandgap reference to assure output voltage accuracy to be within 1% for 1.5V, 1.8V, 2.5V, 2.85V, 3.3V, 5.0V and adjustable versions or 2% for 1.2V version. Current limit is trimmed to ensure specified output current and controlled short-circuit current. On-chip thermal shutdown provides protection against any combination of overload and ambient temperature that would create excessive junction temperature. The AZ1117 has an adjustable version, that can provide the output voltage from 1.25V to 12V with only 2 external resistors.
上传时间： 2019-04-11
上传用户：heaven0o0o0
Abstract—In the future communication applications, users may obtain their messages that have different importance levels distributively from several available sources, such as distributed storage or even devices belonging to other users. This scenario is the best modeled by the multilevel diversity coding systems (MDCS). To achieve perfect (information-theoretic) secrecy against wiretap channels, this paper investigates the fundamental limits on the secure rate region of the asymmetric MDCS (AMDCS), which include the symmetric case as a special case. Threshold perfect secrecy is added to the AMDCS model. The eavesdropper may have access to any one but not more than one subset of the channels but know nothing about the sources, as long as the size of the subset is not above the security level. The question of whether superposition (source separation) coding is optimal for such an AMDCS with threshold perfect secrecy is answered. A class of secure AMDCS (S-AMDCS) with an arbitrary number of encoders is solved, and it is shown that linear codes are optimal for this class of instances. However, in contrast with the secure symmetric MDCS, superposition is shown to be not optimal for S-AMDCS in general. In addition, necessary conditions on the existence of a secrecy key are determined as a design guideline.
标签： Fundamental Limits Secure Class on of
上传时间： 2020-01-04
上传用户：kddlas
The new digital radio system DAB (Digital Audio Broadcasting, nowadays often called Digital Radio) is a very innovative and universal multimedia broadcast system which will replace the existing AM and FM audio broadcast services in many parts of the world in the future. It was developed in the 1990s by the Eureka 147/DAB project. DAB is very well suited for mobile reception and provides very high robustness against multipath reception. It allows use of single frequency networks (SFNs) for high frequency efficiency.
标签： Broadcasting Principles Digital Audio
上传时间： 2020-05-27
上传用户：shancjb
The ever-increasing demand for private and sensitive data transmission over wireless net- works has made security a crucial concern in the current and future large-scale, dynamic, and heterogeneous wireless communication systems. To address this challenge, computer scientists and engineers have tried hard to continuously come up with improved crypto- graphic algorithms. But typically we do not need to wait too long to find an efficient way to crack these algorithms. With the rapid progress of computational devices, the current cryptographic methods are already becoming more unreliable. In recent years, wireless re- searchers have sought a new security paradigm termed physical layer security. Unlike the traditional cryptographic approach which ignores the effect of the wireless medium, physi- cal layer security exploits the important characteristics of wireless channel, such as fading, interference, and noise, for improving the communication security against eavesdropping attacks. This new security paradigm is expected to complement and significantly increase the overall communication security of future wireless networks.
标签： Communications Physical Security Wireless Layer in
上传时间： 2020-05-31
上传用户：shancjb
Spread-spectrum communication is a core area within the field of digital communication. Originally used in military networks as countermeasures against the threats of jamming and interception, spread-spectrum systems are now widely used in commercial applications and are part of several wireless and mobile communication standards. Although spread-spectrum communication is a staple topic in textbooks on digital communication, its treatment is usually cursory. This book is designed to provide a more intensive examination of the subject that is suitable for graduate students and practicing engineers with a solid background in the theory of digital communication. As the title indicates, this book stresses principles rather than specific current or planned systems, which are described in manyotherbooks.My goal in this bookis to providea concisebut lucidexplanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles.
标签： Spread-Spectrum Communication Systems 2nd
上传时间： 2020-06-01
上传用户：shancjb
Electrostatic discharge (ESD) is one of the most prevalent threats to the reliability of electronic components. It is an event in which a finite amount of charge is trans- ferred from one object (i.e., human body) to another (i.e., microchip). This process can result in a very high current passing through the microchip within a very short period of time, and, hence, more than 35% of chip damages can be attributed to an ESD-related event. As such, designing on-chip ESD structures to protect integrated circuits against the ESD stresses is a high priority in the semiconductor industry.
标签： Electrostatic Protection Discharge
上传时间： 2020-06-05
上传用户：shancjb
Welcome to the exciting, empowering world of home automation! If you have ever wanted your home to do more than just protect you against the outside elements and want to interface it to the digital domain, this book will show you how. By demonstrating several easy-to-build projects, you will be able to take the skills you learned from this book and expand upon and apply them toward custom home automation projects of your own design.
标签： Programming Your Hom
上传时间： 2020-06-06
上传用户：shancjb
