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Advances in communication and networking technologies are rapidly making ubiq-
uitous network connectivity a reality. Wireless networks are indispensable for
supporting such access anywhere and at any time. Among various types of wire-
less networks, multihop wireless networks (MWNs) have been attracting increasing
attention for decades due to its broad civilian and military applications. Basically,
a MWN is a network of nodes connected by wireless communication links. Due
to the limited transmission range of the radio, many pairs of nodes in MWNs may
not be able to communicate directly, hence they need other intermediate nodes to
forward packets for them. Routing in such networks is an important issue and it
poses great challenges.
標(biāo)簽：
Multihop
Wireless
Networks
上傳時間：
2020-05-31
上傳用戶：shancjb
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The telecommunications industry has seen a rapid boost within the last decade. New realities
and visions of functionalities in various telecommunications networks have brought forward the
concept of next-generation networks (NGNs). The competitions among operators for support-
ing various services, lowering of the cost of having mobile and cellular phones and smartphones,
increasing demand for general mobility, explosion of digital traffic, and advent of convergence
network technologies added more dynamism in the idea of NGNs. In fact, facilitating con-
vergence of networks and convergence of various types of services is a significant objective of
NGNs.
標(biāo)簽：
Next-Generation
Converged
Networks
上傳時間：
2020-05-31
上傳用戶：shancjb
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This paper presents a Hidden Markov Model (HMM)-based speech
enhancement method, aiming at reducing non-stationary noise from speech
signals. The system is based on the assumption that the speech and the noise
are additive and uncorrelated. Cepstral features are used to extract statistical
information from both the speech and the noise. A-priori statistical
information is collected from long training sequences into ergodic hidden
Markov models. Given the ergodic models for the speech and the noise, a
compensated speech-noise model is created by means of parallel model
combination, using a log-normal approximation. During the compensation, the
mean of every mixture in the speech and noise model is stored. The stored
means are then used in the enhancement process to create the most likely
speech and noise power spectral distributions using the forward algorithm
combined with mixture probability. The distributions are used to generate a
Wiener filter for every observation. The paper includes a performance
evaluation of the speech enhancer for stationary as well as non-stationary
noise environment.
標(biāo)簽：
Telecommunications
Processing
Signal
for
上傳時間：
2020-06-01
上傳用戶：shancjb
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A wireless ad-hoc network is a wireless network deployed without any infrastructure. In
such a network, there is no access point or wireless router to forward messages among the
computing devices. Instead, these devices depend on the ad-hoc mode of their wireless net‐
work interface cards to communicate with each other. If the nodes are within the transmis‐
sion range of the wireless signal, they can send messages to each other directly. Otherwise,
the nodes in between will forward the messages for them. Thus, each node is both an end
system and a router simultaneously.
標(biāo)簽：
WIRELESS
NETWORKS
AD-HOC
上傳時間：
2020-06-01
上傳用戶：shancjb
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In the field of electricity, electrostatics, and circuit theory, there are many discoveries and
accomplishments that have lead to the foundation of the field of electrostatic discharge
(ESD) phenomenon. Below is a chronological list of key events that moved the field of
electrostatics forward:
標(biāo)簽：
Circuits
Devices
ESD
and
上傳時間：
2020-06-05
上傳用戶：shancjb
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RFID is at a critical price point that could enable its large-scale adoption.
What strengths are pushing it forward? What technical challenges and
privacy concerns must we still address?
標(biāo)簽：
an-introduction-to-rfid-technolog
上傳時間：
2020-06-08
上傳用戶：shancjb
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Recent work has shown that convolutional networks can
be substantially deeper, more accurate, and efficient to train
if they contain shorter connections between layers close to
the input and those close to the output. In this paper, we
embrace this observation and introduce the Dense Convo-
lutional Network (DenseNet), which connects each layer
to every other layer in a feed-forward fashion.
標(biāo)簽：
Convolutional
Connected
Networks
Densely
上傳時間：
2020-06-10
上傳用戶：shancjb
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ABSTRACTThe flyback power stage is a popular choice for single and multiple output dc-to-dc converters at powerlevels of 150 Watts or less. Without the output inductor required in buck derived topologies, such as theforward or push-pull converter, the component count and cost are reduced. This application note will reviewthe design procedure for the power stage and control electronics of a flyback converter. In these isolatedconverters, the error signal from the secondary still needs to cross the isolation boundary to achieveregulation. By using the UC3965 Precision Reference with Low Offset Error Amplifier on the secondaryside to drive an optocoupler and the UCC3809 Economy Primary Side Controller on the primary side, asimple and low cost 50 Watt isolated power supply is realized.
標(biāo)簽：
隔離
上傳時間：
2021-11-24
上傳用戶：kingwide
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This Section covers the design of power transformers used in buck-derived topologies: forward converter, bridge, half-bridge, and full-wave centertap. Flyback transformers (actually coupled inductors) are covered in a later Section. For more specialized applications, the principles discussed herein will generally apply.
標(biāo)簽：
反激變換器
變壓器
上傳時間：
2021-12-16
上傳用戶：fliang
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以STC12C5A60S2單片機為控制核心,采用2.4G(JF24D)無線遙控模塊進(jìn)行無線發(fā)射與接收,設(shè)計了一種雙電機遙控船模控制系統(tǒng).該系統(tǒng)通過切換檔桿實現(xiàn)前進(jìn)后退,方向盤左右轉(zhuǎn)動、暫停按鈕等控制直流電機的正轉(zhuǎn)、反轉(zhuǎn)、暫停,使得電機驅(qū)動的遙控船模實現(xiàn)前進(jìn)后退、左右轉(zhuǎn)向、暫停等功能,有效解決了驅(qū)動功率小和船模之間相互干擾等問題,可廣泛應(yīng)用于遙控船模領(lǐng)域.Using STC12C5A60S2 single-chip microcomputer as the controller and 2.4 G(JF24D)wireless remote control module for wireless transmission and reception, a dual-motor remote control ship model control system is designed. The system realizes forward and backward by switching the gear lever. The steering wheel rotates left and right and the pause button controls the forward, reverse and pause of the dc motor. The remote controller of ship model driven by the motor realizes forward and backward, left and right steering, pause and other functions. The ship model control system can effectively solve the problems of small driving power and mutual interference between ship models, and can be widely used in the field of remote controller of ship model.
標(biāo)簽：
電機
遙控船模
控制系統(tǒng)
上傳時間：
2022-03-27
上傳用戶：
