The through silicon via (TSV) technology has proven to be the critical enabler to realize a three-dimensional (3D) gigscale system with higher performance but shorter interconnect length. However, the received dig...The through silicon via (TSV) technology has proven to be the critical enabler to realize a three-dimensional (3D) gigscale system with higher performance but shorter interconnect length. However, the received digital signal after trans- mission through a TSV channel, composed of redistribution layers (RDLs), TSVs, and bumps, is degraded at a high data-rate due to the non-idealities of the channel. We propose the Chebyshev multisection transformers to reduce the signal reflec- tion of TSV channel when operating frequency goes up to 20 GHz, by which signal reflection coefficient ($11) and signal transmission coefficient ($21) are improved remarkably by 150% and 73.3%, respectively. Both the time delay and power dissipation are also reduced by 4% and 13.3%, respectively. The resistance-inductance-conductance-capacitance (RLGC) elements of the TSV channel are iterated from scattering (S)-parameters, and the proposed method of weakening the signal reflection is verified using high frequency simulator structure (HFSS) simulation software by Ansoft.展开更多
To reduce the negative impact of the power amplifier(PA)nonlinear distortion caused by the orthogonal frequency division multiplexing(OFDM)waveform with high peak-to-average power ratio(PAPR)in integrated radar and co...To reduce the negative impact of the power amplifier(PA)nonlinear distortion caused by the orthogonal frequency division multiplexing(OFDM)waveform with high peak-to-average power ratio(PAPR)in integrated radar and communication(RadCom)systems is studied,the channel estimation in passive sensing scenarios.Adaptive channel estimation methods are proposed based on different pilot patterns,considering nonlinear distortion and channel sparsity.The proposed methods achieve sparse channel results by manipulating the least squares(LS)frequency-domain channel estimation results to preserve the most significant taps.The decision-aided method is used to optimize the sparse channel results to reduce the effect of nonlinear distortion.Numerical results show that the channel estimation performance of the proposed methods is better than that of the conventional methods under different pilot patterns.In addition,the bit error rate performance in communication and passive radar detection performance show that the proposed methods have good comprehensive performance.展开更多
With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only...With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different businessmodes, then apply the corresponding O2Oprocess to the mode, so as to broaden the enterprise selling channels for a better development.展开更多
With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only...With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.展开更多
With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only...With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.展开更多
Integrated data and energy transfer(IDET)is capable of simultaneously delivering on-demand data and energy to low-power Internet of Everything(Io E)devices.We propose a multi-carrier IDET transceiver relying on superp...Integrated data and energy transfer(IDET)is capable of simultaneously delivering on-demand data and energy to low-power Internet of Everything(Io E)devices.We propose a multi-carrier IDET transceiver relying on superposition waveforms consisting of multi-sinusoidal signals for wireless energy transfer(WET)and orthogonal-frequency-divisionmultiplexing(OFDM)signals for wireless data transfer(WDT).The outdated channel state information(CSI)in aging channels is employed by the transmitter to shape IDET waveforms.With the constraints of transmission power and WDT requirement,the amplitudes and phases of the IDET waveform at the transmitter and the power splitter at the receiver are jointly optimised for maximising the average directcurrent(DC)among a limited number of transmission frames with the existence of carrier-frequencyoffset(CFO).For the amplitude optimisation,the original non-convex problem can be transformed into a reversed geometric programming problem,then it can be effectively solved with existing tools.As for the phase optimisation,the artificial bee colony(ABC)algorithm is invoked in order to deal with the nonconvexity.Iteration between the amplitude optimisation and phase optimisation yields our joint design.Numerical results demonstrate the advantage of our joint design for the IDET waveform shaping with the existence of the CFO and the outdated CSI.展开更多
Strained-Si0.73Ge0.27 channels are successfully integrated with high-R/metal gates in p-type metai-oxide- semi- conductor field effect transistors (pMOSFETs) using the replacement post-gate process. A silicon cap an...Strained-Si0.73Ge0.27 channels are successfully integrated with high-R/metal gates in p-type metai-oxide- semi- conductor field effect transistors (pMOSFETs) using the replacement post-gate process. A silicon cap and oxide inter layers are inserted between Si0.73Ge0.27 and high-κ dielectric to improve the interface. The fab- ricated Si0.73Ge0.27 pMOSFETs with gate length of 3Onto exhibit good performance with high drive current (~428μA/μm at VDD = 1 V) and suppressed short-channel effects (DIBL^77mV/V and SS^90mV/decade). It is found that the enhancement of effective hole mobility is up to 200% in long-gate-length Si0.73Ge0.27-channel pMOSFETs compared with the corresponding silicon transistors. The improvement of device performance is reduced due to strain relaxation as the gate length decreases, while 26% increase of the drive current is still obtained for 30-nm-gate-length Si0.73Ge0.27 devices.展开更多
An 'Integrated Device and Circuit simulator' for thin film (0.05-0.2μm) submicron (0.5μm) and deep submicron (0.15, 0.25,0.35μm) CMOS/ SOI integrated circuit has been developed. This simulator has been used...An 'Integrated Device and Circuit simulator' for thin film (0.05-0.2μm) submicron (0.5μm) and deep submicron (0.15, 0.25,0.35μm) CMOS/ SOI integrated circuit has been developed. This simulator has been used for design and fabrication and physical library development of thin film submicron and deep submicron CMOS/ SOI integrated circuit.展开更多
Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this pape...Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this paper is to salvage as many data from the damaged packets as possible for higher audiovisual quality. This paper proposes an integrated joint source-channel decoder (I-JSCD) at a symbol-level using three-dimensional (3-D) trellis representation for first-order Markov sources encoded with VLC source code and convolutional channel code. This method combines source code and channel code state-spaces and bit-lengths to construct a two-dimensional (2-D) state-space, and then develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol. Experiment results demonstrate that our method results in significant improvement in decoding performance, it can salvage at least half of (50%) data in any channel error rate, and can provide additional error resilience to VLC stream like image, audio, video stream over high error rate links.展开更多
A CMOS front-end integrated circuit consisting of 16 identical analog channels is proposed for semiconductor radiation detectors. Each of the 16 channels has a low noise charge sensitive amplifier, a pulse shaper, a p...A CMOS front-end integrated circuit consisting of 16 identical analog channels is proposed for semiconductor radiation detectors. Each of the 16 channels has a low noise charge sensitive amplifier, a pulse shaper, a peak detect and hold circuit and a discriminator, while analog voltage and channel address are routed off the chip. It can accommodate both electron and hole collection with selectable gain and peaking time. Sequential and sparse readout, combining with self-trigger and external trigger, makes four readout modes. The circuit is implemented in a 0.35 μm DP4M (double-poly-quad-metal) CMOS technology with an area of 2.5×1.54 mm2 and power dissipation of 60 mW. A single channel chip is tested with Verigy 93000. The gain is adjustable from 13 to 130 mV·fC–1 while the peaking time varies between 0.7 and 1.6 μs. The linearity is more than 99% and the equivalent noise charge is about 600e.展开更多
This paper proposes an integrated joint source-channel decoder (I-JSCD) using Max-Log-MAP method for sources encoded with exp-Golomb codes and convolutional codes, and proposes a system applying this method to decod...This paper proposes an integrated joint source-channel decoder (I-JSCD) using Max-Log-MAP method for sources encoded with exp-Golomb codes and convolutional codes, and proposes a system applying this method to decoding the VLC data, e.g. motion vector differences (MVDs), of H.264 across an AWGN channel. This method combines the source code state-space and the channel code state-space together to construct a joint state-space, develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol, and then uses max-log approximation to simplify the algorithm. Experiments indicate that the proposed system gives significant improvements on peak signal-to-noise ratio (PSNR) (maximum about 15 dB) than a separate scheme. This also leads to a higher visual quality of video stream over a highly noisy channel.展开更多
We review recent work on broadband RF channelizers based on integrated optical frequency Kerr micro-combs combined with passive micro-ring resonator filters,with microcombs having channel spacings of 200 and 49 GHz.Th...We review recent work on broadband RF channelizers based on integrated optical frequency Kerr micro-combs combined with passive micro-ring resonator filters,with microcombs having channel spacings of 200 and 49 GHz.This approach to realizing RF channelizers offers reduced complexity,size,and potential cost for a wide range of applications to microwave signal detection.展开更多
We propose and experimentally demonstrate an integrated silicon photonic scheme to generate multi-channel millimeter-wave(MMW) signals for 5 G multi-user applications. The fabricated silicon photonic chip has a footpr...We propose and experimentally demonstrate an integrated silicon photonic scheme to generate multi-channel millimeter-wave(MMW) signals for 5 G multi-user applications. The fabricated silicon photonic chip has a footprint of 1.1 × 2.1 mm^2 and integrates 7 independent channels each having on-chip polarization control and heterodyne mixing functions. 7 channels of4-Gb/s QPSK baseband signals are delivered via a 2-km multi-core fiber(MCF) and coupled into the chip with a local oscillator(LO) light. The polarization state of each signal light is automatically adjusted and aligned with that of the LO light, and then 7 channels of 28-GHz MMW carrying 4-Gb/s QPSK signals are generated by optical heterodyne beating. Automated polarizationcontrol function of each channel is also demonstrated with ~7-ms tuning time and ~27-dB extinction ratio.展开更多
We find the time evolution law of a negative binomial optical field in a diffusion channel. We reveal that by adjusting the diffusion parameter, the photon number can be controlled. Therefore, the diffusion process ca...We find the time evolution law of a negative binomial optical field in a diffusion channel. We reveal that by adjusting the diffusion parameter, the photon number can be controlled. Therefore, the diffusion process can be considered a quantum controlling scheme through photon addition.展开更多
This paper proposes the concept of transaction-type covert storage channels, which are caused by database storage resources. It also proposes that the mode of auditing those channels be based on the transactions. Next...This paper proposes the concept of transaction-type covert storage channels, which are caused by database storage resources. It also proposes that the mode of auditing those channels be based on the transactions. Next, the paper analyzes and resolves the two problems arising from auditing the use of transaction-type covert storage channels in database systems: namely, the relationship between channel variables, which are altered (or viewed) by the transaction and satisfy integrity constraints in DBMS, and database states; and the circumvention of covert storage channel audit in DBMS.展开更多
The Singular Integral Operators Method (S.I.O.M.) is applied to the determination of the free-surface profile of an un-steady flow over a spillway, which defines a classical hydraulics problem in open channel flow. Th...The Singular Integral Operators Method (S.I.O.M.) is applied to the determination of the free-surface profile of an un-steady flow over a spillway, which defines a classical hydraulics problem in open channel flow. Thus, with a known flow rate Q, then the velocities and the elevations are computed on the free surface of the spillway flow. For the numerical evaluation of the singular integral equations both constant and linear elements are used. An application is finally given to the determination of the free-surface profile of a special spillway and comparing the numerical results with corresponding results by the Boundary Integral Equation Method (B.I.E.M.) and by using experiments.展开更多
As the process of economic globalization deepens,a large variety of integrated circuit designers tends to move the chip's manufacturing to the developing country.But during the globalization of semiconductor desig...As the process of economic globalization deepens,a large variety of integrated circuit designers tends to move the chip's manufacturing to the developing country.But during the globalization of semiconductor design and fabrication process,integrated circuits are suffering from increasing malicious alterations from the untrusted foundries,which pose a serious threat to the military,finance,transportation and other critical systems.An noninvasive approach was presented to measure the physical "sidechannel"parameter of a chip such as current or delay,which is effectively capable of detecting the malicious hardware alternations.The intrinsic relationship of a circuit's side-channel parameters was exploited to distinguish the effect of a Trojan in the presence of large random noise and process noise,such as the Dynamic current(IDDT)versus the maximum operating frequency(Fmax)correlation.The Monte Carlo analysis in Hspice using ± 20% Gauss variations in transistor threshold voltage(Vth)was carried out to simulate the circuit state in the real world.Simulation Results show that this approach is effective to detect the ultra-small Trojans.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61204044)
文摘The through silicon via (TSV) technology has proven to be the critical enabler to realize a three-dimensional (3D) gigscale system with higher performance but shorter interconnect length. However, the received digital signal after trans- mission through a TSV channel, composed of redistribution layers (RDLs), TSVs, and bumps, is degraded at a high data-rate due to the non-idealities of the channel. We propose the Chebyshev multisection transformers to reduce the signal reflec- tion of TSV channel when operating frequency goes up to 20 GHz, by which signal reflection coefficient ($11) and signal transmission coefficient ($21) are improved remarkably by 150% and 73.3%, respectively. Both the time delay and power dissipation are also reduced by 4% and 13.3%, respectively. The resistance-inductance-conductance-capacitance (RLGC) elements of the TSV channel are iterated from scattering (S)-parameters, and the proposed method of weakening the signal reflection is verified using high frequency simulator structure (HFSS) simulation software by Ansoft.
基金supported by the National Natural Science Foundation of China(61931015,62071335,62250024)the Natural Science Foundation of Hubei Province of China(2021CFA002)+1 种基金the Fundamental Research Funds for the Central Universities of China(2042022dx0001)the Science and Technology Program of Shenzhen(JCYJ20170818112037398).
文摘To reduce the negative impact of the power amplifier(PA)nonlinear distortion caused by the orthogonal frequency division multiplexing(OFDM)waveform with high peak-to-average power ratio(PAPR)in integrated radar and communication(RadCom)systems is studied,the channel estimation in passive sensing scenarios.Adaptive channel estimation methods are proposed based on different pilot patterns,considering nonlinear distortion and channel sparsity.The proposed methods achieve sparse channel results by manipulating the least squares(LS)frequency-domain channel estimation results to preserve the most significant taps.The decision-aided method is used to optimize the sparse channel results to reduce the effect of nonlinear distortion.Numerical results show that the channel estimation performance of the proposed methods is better than that of the conventional methods under different pilot patterns.In addition,the bit error rate performance in communication and passive radar detection performance show that the proposed methods have good comprehensive performance.
文摘With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different businessmodes, then apply the corresponding O2Oprocess to the mode, so as to broaden the enterprise selling channels for a better development.
文摘With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.
文摘With the rapid development of information technology, it appears that a single online channel or a single offline is not able to meet the consumers' shopping needs, the enterprises will have a better development only by making the online and offline channels be in fusion and promote each other. This paper will combine the general business modes with corporate channel integration pattern, build out different forms of the market mode including market, enterprise and customers basing on different influence level, and analyze out the enterprise how to implement the business mode of integration basing on the influence factors under the background of different business modes, then apply the corresponding O2O process to the mode, so as to broaden the enterprise selling channels for a better development.
基金financial support of Natural Science Foundation of China(No.61971102,62132004)MOST Major Research and Development Project(No.2021YFB2900204)+1 种基金Sichuan Science and Technology Program(No.2022YFH0022)Key Research and Development Program of Zhejiang Province(No.2022C01093)。
文摘Integrated data and energy transfer(IDET)is capable of simultaneously delivering on-demand data and energy to low-power Internet of Everything(Io E)devices.We propose a multi-carrier IDET transceiver relying on superposition waveforms consisting of multi-sinusoidal signals for wireless energy transfer(WET)and orthogonal-frequency-divisionmultiplexing(OFDM)signals for wireless data transfer(WDT).The outdated channel state information(CSI)in aging channels is employed by the transmitter to shape IDET waveforms.With the constraints of transmission power and WDT requirement,the amplitudes and phases of the IDET waveform at the transmitter and the power splitter at the receiver are jointly optimised for maximising the average directcurrent(DC)among a limited number of transmission frames with the existence of carrier-frequencyoffset(CFO).For the amplitude optimisation,the original non-convex problem can be transformed into a reversed geometric programming problem,then it can be effectively solved with existing tools.As for the phase optimisation,the artificial bee colony(ABC)algorithm is invoked in order to deal with the nonconvexity.Iteration between the amplitude optimisation and phase optimisation yields our joint design.Numerical results demonstrate the advantage of our joint design for the IDET waveform shaping with the existence of the CFO and the outdated CSI.
基金Supported by the National Basic Research Program of China under Grant No 2011CBA00605the National Natural Science Foundation of China under Grant No 61404165
文摘Strained-Si0.73Ge0.27 channels are successfully integrated with high-R/metal gates in p-type metai-oxide- semi- conductor field effect transistors (pMOSFETs) using the replacement post-gate process. A silicon cap and oxide inter layers are inserted between Si0.73Ge0.27 and high-κ dielectric to improve the interface. The fab- ricated Si0.73Ge0.27 pMOSFETs with gate length of 3Onto exhibit good performance with high drive current (~428μA/μm at VDD = 1 V) and suppressed short-channel effects (DIBL^77mV/V and SS^90mV/decade). It is found that the enhancement of effective hole mobility is up to 200% in long-gate-length Si0.73Ge0.27-channel pMOSFETs compared with the corresponding silicon transistors. The improvement of device performance is reduced due to strain relaxation as the gate length decreases, while 26% increase of the drive current is still obtained for 30-nm-gate-length Si0.73Ge0.27 devices.
文摘An 'Integrated Device and Circuit simulator' for thin film (0.05-0.2μm) submicron (0.5μm) and deep submicron (0.15, 0.25,0.35μm) CMOS/ SOI integrated circuit has been developed. This simulator has been used for design and fabrication and physical library development of thin film submicron and deep submicron CMOS/ SOI integrated circuit.
基金Supported by the Foundation of Ministry of Education of China (211CERS10)
文摘Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this paper is to salvage as many data from the damaged packets as possible for higher audiovisual quality. This paper proposes an integrated joint source-channel decoder (I-JSCD) at a symbol-level using three-dimensional (3-D) trellis representation for first-order Markov sources encoded with VLC source code and convolutional channel code. This method combines source code and channel code state-spaces and bit-lengths to construct a two-dimensional (2-D) state-space, and then develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol. Experiment results demonstrate that our method results in significant improvement in decoding performance, it can salvage at least half of (50%) data in any channel error rate, and can provide additional error resilience to VLC stream like image, audio, video stream over high error rate links.
基金Supported by the National Natural Science Foundation of China (No.40704025)
文摘A CMOS front-end integrated circuit consisting of 16 identical analog channels is proposed for semiconductor radiation detectors. Each of the 16 channels has a low noise charge sensitive amplifier, a pulse shaper, a peak detect and hold circuit and a discriminator, while analog voltage and channel address are routed off the chip. It can accommodate both electron and hole collection with selectable gain and peaking time. Sequential and sparse readout, combining with self-trigger and external trigger, makes four readout modes. The circuit is implemented in a 0.35 μm DP4M (double-poly-quad-metal) CMOS technology with an area of 2.5×1.54 mm2 and power dissipation of 60 mW. A single channel chip is tested with Verigy 93000. The gain is adjustable from 13 to 130 mV·fC–1 while the peaking time varies between 0.7 and 1.6 μs. The linearity is more than 99% and the equivalent noise charge is about 600e.
基金Supported by the Foundation of Ministry of Education of China (211CERS10)
文摘This paper proposes an integrated joint source-channel decoder (I-JSCD) using Max-Log-MAP method for sources encoded with exp-Golomb codes and convolutional codes, and proposes a system applying this method to decoding the VLC data, e.g. motion vector differences (MVDs), of H.264 across an AWGN channel. This method combines the source code state-space and the channel code state-space together to construct a joint state-space, develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol, and then uses max-log approximation to simplify the algorithm. Experiments indicate that the proposed system gives significant improvements on peak signal-to-noise ratio (PSNR) (maximum about 15 dB) than a separate scheme. This also leads to a higher visual quality of video stream over a highly noisy channel.
文摘We review recent work on broadband RF channelizers based on integrated optical frequency Kerr micro-combs combined with passive micro-ring resonator filters,with microcombs having channel spacings of 200 and 49 GHz.This approach to realizing RF channelizers offers reduced complexity,size,and potential cost for a wide range of applications to microwave signal detection.
基金supported by the National Key R&D Pro-gram of China under Grant 2016YFB0402501in part by the Natural Science Foundation of China under grant 61605112Open Fund of IPOC under grant BUPT
文摘We propose and experimentally demonstrate an integrated silicon photonic scheme to generate multi-channel millimeter-wave(MMW) signals for 5 G multi-user applications. The fabricated silicon photonic chip has a footprint of 1.1 × 2.1 mm^2 and integrates 7 independent channels each having on-chip polarization control and heterodyne mixing functions. 7 channels of4-Gb/s QPSK baseband signals are delivered via a 2-km multi-core fiber(MCF) and coupled into the chip with a local oscillator(LO) light. The polarization state of each signal light is automatically adjusted and aligned with that of the LO light, and then 7 channels of 28-GHz MMW carrying 4-Gb/s QPSK signals are generated by optical heterodyne beating. Automated polarizationcontrol function of each channel is also demonstrated with ~7-ms tuning time and ~27-dB extinction ratio.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB922103)the National Natural Science Foundation of China(Grant Nos.11175113,11274104,and 11404108)the Natural Science Foundation of Hubei Province,China(Grant No.2011CDA021)
文摘We find the time evolution law of a negative binomial optical field in a diffusion channel. We reveal that by adjusting the diffusion parameter, the photon number can be controlled. Therefore, the diffusion process can be considered a quantum controlling scheme through photon addition.
文摘This paper proposes the concept of transaction-type covert storage channels, which are caused by database storage resources. It also proposes that the mode of auditing those channels be based on the transactions. Next, the paper analyzes and resolves the two problems arising from auditing the use of transaction-type covert storage channels in database systems: namely, the relationship between channel variables, which are altered (or viewed) by the transaction and satisfy integrity constraints in DBMS, and database states; and the circumvention of covert storage channel audit in DBMS.
文摘The Singular Integral Operators Method (S.I.O.M.) is applied to the determination of the free-surface profile of an un-steady flow over a spillway, which defines a classical hydraulics problem in open channel flow. Thus, with a known flow rate Q, then the velocities and the elevations are computed on the free surface of the spillway flow. For the numerical evaluation of the singular integral equations both constant and linear elements are used. An application is finally given to the determination of the free-surface profile of a special spillway and comparing the numerical results with corresponding results by the Boundary Integral Equation Method (B.I.E.M.) and by using experiments.
文摘As the process of economic globalization deepens,a large variety of integrated circuit designers tends to move the chip's manufacturing to the developing country.But during the globalization of semiconductor design and fabrication process,integrated circuits are suffering from increasing malicious alterations from the untrusted foundries,which pose a serious threat to the military,finance,transportation and other critical systems.An noninvasive approach was presented to measure the physical "sidechannel"parameter of a chip such as current or delay,which is effectively capable of detecting the malicious hardware alternations.The intrinsic relationship of a circuit's side-channel parameters was exploited to distinguish the effect of a Trojan in the presence of large random noise and process noise,such as the Dynamic current(IDDT)versus the maximum operating frequency(Fmax)correlation.The Monte Carlo analysis in Hspice using ± 20% Gauss variations in transistor threshold voltage(Vth)was carried out to simulate the circuit state in the real world.Simulation Results show that this approach is effective to detect the ultra-small Trojans.