A new distribution principle of bus protection is presented.The protection system description,its design features,hardware structure,construction of data communication network are given.Dynamic simulation experiments ...A new distribution principle of bus protection is presented.The protection system description,its design features,hardware structure,construction of data communication network are given.Dynamic simulation experiments show its distinguishing advantages over traditional centralized principle.展开更多
The interaction between the heat source location, its intensity, thermal expansion coefficient, the machine system configuration and the running environment creates complex thermal behavior of a machine tool, and also...The interaction between the heat source location, its intensity, thermal expansion coefficient, the machine system configuration and the running environment creates complex thermal behavior of a machine tool, and also makes thermal error prediction difficult. To address this issue, a novel prediction method for machine tool thermal error based on Bayesian networks (BNs) was presented. The method described causal relationships of factors inducing thermal deformation by graph theory and estimated the thermal error by Bayesian statistical techniques. Due to the effective combination of domain knowledge and sampled data, the BN method could adapt to the change of running state of machine, and obtain satisfactory prediction accuracy. Ex- periments on spindle thermal deformation were conducted to evaluate the modeling performance. Experimental results indicate that the BN method performs far better than the least squares (LS) analysis in terms of modeling estimation accuracy.展开更多
Public key cryptographic （PKC） algorithms, such as the RSA, elliptic curve digital signature algorithm （ECDSA） etc., are widely used in the secure communication sys- tems, such as OpenSSL, and a variety of in- for...Public key cryptographic （PKC） algorithms, such as the RSA, elliptic curve digital signature algorithm （ECDSA） etc., are widely used in the secure communication sys- tems, such as OpenSSL, and a variety of in- formation security systems. If designer do not securely implement them, the secret key will be easily extracted by side-channel attacks （SCAs） or combinational SCA thus mitigat- ing the security of the entire communication system. Previous countermeasures of PKC im- plementations focused on the core part of the algorithms and ignored the modular inversion which is widely used in various PKC schemes. Many researchers believe that instead of straightforward implementation, constant time modular inversion （CTMI） is enough to resist the attack of simple power analysis combined with lattice analysis. However, we find that the CTMI security can be reduced to a hidden t-bit multiplier problem. Based on this feature, we firstly obtain Hamming weight of interme- diate data through side-channel leakage. Then, we propose a heuristic algorithm to solve the problem by revealing the secret （partial and full） base of CTMI. Comparing previous nec-essary input message for masking filtering, our procedure need not any information about the secret base of the inversion. To our knowl- edge, this is the first time for evaluating the practical security of CTM! and experimental results show the fact that CTMI is not enough for high-level secure communication systems.展开更多
Media literacy and understanding the digital information around us are an area of communication that affects all of us. How people are represented in the media, social media and our civic participation affect our repr...Media literacy and understanding the digital information around us are an area of communication that affects all of us. How people are represented in the media, social media and our civic participation affect our representations and understanding of the truth. The author would argue through research and practical examples that civic engagement and associations with a peer group can counteract some of the issues facing digital media today. In an age of the so-called ＂fake news,＂ there are tools we can provide for our teams, our employees, and our collaborators to make sure we are all on the same page and dealing with the same set of verifiable facts展开更多
High-resolution bathymetric side-scan sonar(BSSS) performs the functions of traditional side-scan sonar, while also providing a depth-sounding function that allows simultaneous measurement of seafloor topography and g...High-resolution bathymetric side-scan sonar(BSSS) performs the functions of traditional side-scan sonar, while also providing a depth-sounding function that allows simultaneous measurement of seafloor topography and geomorphology. Submarine microtopography and microgeomorphology detection ability and advanced underwater acoustic digital communication are important technical capabilities of the Jiaolong manned submersible. High resolution BSSS achieved accurate detection of seafloor topography and geomorphology at a depth of 7000 m, and successful mapping of local microtopography and microgeomorphology in the Mariana Trench.展开更多
The current massive use of digital communications demands a secure link by using an embedded system（ES） with data encryption at the protocol level. The serial peripheral interface（SPI） protocol is commonly used by...The current massive use of digital communications demands a secure link by using an embedded system（ES） with data encryption at the protocol level. The serial peripheral interface（SPI） protocol is commonly used by manufacturers of ESs and integrated circuits for applications in areas such as wired and wireless communications. We present the design and experimental implementation of a chaotic encryption and decryption algorithm applied to the SPI communication protocol. The design of the chaotic encryption algorithm along with its counterpart in the decryption is based on the chaotic Hénon map and two methods for blur and permute（in combination with DNA sequences）. The SPI protocol is configured in 16 bits to synchronize a transmitter and a receiver considering a symmetric key. Results are experimentally proved using two low-cost dsPIC microcontrollers as ESs. The SPI digital-to-analog converter is used to process, acquire, and reconstruct confidential messages based on its properties for digital signal processing. Finally, security of the cryptogram is proved by a statistical test. The digital processing capacity of the algorithm is validated by dsPIC microcontrollers.展开更多
This paper addresses a channel scheduling problem for group of dynamically decoupled nonlinear subsystems with actuators connected through digital communication channels and controlled by a centralized controller. Due...This paper addresses a channel scheduling problem for group of dynamically decoupled nonlinear subsystems with actuators connected through digital communication channels and controlled by a centralized controller. Due to the limited communication capacity, only one channel can be activated and hence there is only one pair of sensor and actuator can communicate with the controller at each time instant. In addition, the communication channels are not reliable so Markovian packed dropout is introduced. A predictive control framework is adopted for controller/scheduler co-design to alleviate the performance loss caused by the limited communication capacity. Instead of sending a single control value, the controller sends a sequence of predicted control values to a selected actuator so that there are control input candidates which can be fed to the subsystem when the actuator does not communicate with the controller. A stochastic algorithm is proposed to schedule the usage of the communication medium and sufficient conditions on stochastic stability are given under some mild assumptions.展开更多
文摘A new distribution principle of bus protection is presented.The protection system description,its design features,hardware structure,construction of data communication network are given.Dynamic simulation experiments show its distinguishing advantages over traditional centralized principle.
基金Project supported by National Natural Science Foundation of China(No. 50675199)the Science and Technology Project of Zhejiang Province (No. 2006C11067), China
文摘The interaction between the heat source location, its intensity, thermal expansion coefficient, the machine system configuration and the running environment creates complex thermal behavior of a machine tool, and also makes thermal error prediction difficult. To address this issue, a novel prediction method for machine tool thermal error based on Bayesian networks (BNs) was presented. The method described causal relationships of factors inducing thermal deformation by graph theory and estimated the thermal error by Bayesian statistical techniques. Due to the effective combination of domain knowledge and sampled data, the BN method could adapt to the change of running state of machine, and obtain satisfactory prediction accuracy. Ex- periments on spindle thermal deformation were conducted to evaluate the modeling performance. Experimental results indicate that the BN method performs far better than the least squares (LS) analysis in terms of modeling estimation accuracy.
基金supported by the Key Technology Research and Sample-Chip Manufacture on Resistance to Physical Attacks at Circuit Level(546816170002)
文摘Public key cryptographic （PKC） algorithms, such as the RSA, elliptic curve digital signature algorithm （ECDSA） etc., are widely used in the secure communication sys- tems, such as OpenSSL, and a variety of in- formation security systems. If designer do not securely implement them, the secret key will be easily extracted by side-channel attacks （SCAs） or combinational SCA thus mitigat- ing the security of the entire communication system. Previous countermeasures of PKC im- plementations focused on the core part of the algorithms and ignored the modular inversion which is widely used in various PKC schemes. Many researchers believe that instead of straightforward implementation, constant time modular inversion （CTMI） is enough to resist the attack of simple power analysis combined with lattice analysis. However, we find that the CTMI security can be reduced to a hidden t-bit multiplier problem. Based on this feature, we firstly obtain Hamming weight of interme- diate data through side-channel leakage. Then, we propose a heuristic algorithm to solve the problem by revealing the secret （partial and full） base of CTMI. Comparing previous nec-essary input message for masking filtering, our procedure need not any information about the secret base of the inversion. To our knowl- edge, this is the first time for evaluating the practical security of CTM! and experimental results show the fact that CTMI is not enough for high-level secure communication systems.
文摘Media literacy and understanding the digital information around us are an area of communication that affects all of us. How people are represented in the media, social media and our civic participation affect our representations and understanding of the truth. The author would argue through research and practical examples that civic engagement and associations with a peer group can counteract some of the issues facing digital media today. In an age of the so-called ＂fake news,＂ there are tools we can provide for our teams, our employees, and our collaborators to make sure we are all on the same page and dealing with the same set of verifiable facts
基金supported by the National Key R&D Program of China (Grant No. 2017YFC0305700)the Qingdao National Laboratory for Marine Science and Technology (Grant No. QNLM2016ORP0406)+4 种基金the National Natural Science Foundation of China (Grant No. 41641049)the Taishan Scholar Project Funding (Grant No. TSPD20161007)the Shandong Provincial Natural Science Foundation (Grant No. ZR2015EM005)the Shandong Provincial Key R&D Program (Grant No. 2016GSF115006)the Qingdao Independent Innovation Project (Grant No. 15-9-1-90-JCH)
文摘High-resolution bathymetric side-scan sonar(BSSS) performs the functions of traditional side-scan sonar, while also providing a depth-sounding function that allows simultaneous measurement of seafloor topography and geomorphology. Submarine microtopography and microgeomorphology detection ability and advanced underwater acoustic digital communication are important technical capabilities of the Jiaolong manned submersible. High resolution BSSS achieved accurate detection of seafloor topography and geomorphology at a depth of 7000 m, and successful mapping of local microtopography and microgeomorphology in the Mariana Trench.
基金Project supported by the CONACYT,México(No.166654)
文摘The current massive use of digital communications demands a secure link by using an embedded system（ES） with data encryption at the protocol level. The serial peripheral interface（SPI） protocol is commonly used by manufacturers of ESs and integrated circuits for applications in areas such as wired and wireless communications. We present the design and experimental implementation of a chaotic encryption and decryption algorithm applied to the SPI communication protocol. The design of the chaotic encryption algorithm along with its counterpart in the decryption is based on the chaotic Hénon map and two methods for blur and permute（in combination with DNA sequences）. The SPI protocol is configured in 16 bits to synchronize a transmitter and a receiver considering a symmetric key. Results are experimentally proved using two low-cost dsPIC microcontrollers as ESs. The SPI digital-to-analog converter is used to process, acquire, and reconstruct confidential messages based on its properties for digital signal processing. Finally, security of the cryptogram is proved by a statistical test. The digital processing capacity of the algorithm is validated by dsPIC microcontrollers.
基金supported by the Energy Innovation Research Programme of Singapore under Grant No.NRF2013EWT-EIRP004-012Qilu Youth Scholar Discipline Construction Funding from Shandong University+1 种基金the National Natural Science Foundation of China(NSFC)under Grant Nos.61573220,61633014Projects of Major International(Regional)Joint Research Program NSFC under Grant No.61720106011
文摘This paper addresses a channel scheduling problem for group of dynamically decoupled nonlinear subsystems with actuators connected through digital communication channels and controlled by a centralized controller. Due to the limited communication capacity, only one channel can be activated and hence there is only one pair of sensor and actuator can communicate with the controller at each time instant. In addition, the communication channels are not reliable so Markovian packed dropout is introduced. A predictive control framework is adopted for controller/scheduler co-design to alleviate the performance loss caused by the limited communication capacity. Instead of sending a single control value, the controller sends a sequence of predicted control values to a selected actuator so that there are control input candidates which can be fed to the subsystem when the actuator does not communicate with the controller. A stochastic algorithm is proposed to schedule the usage of the communication medium and sufficient conditions on stochastic stability are given under some mild assumptions.
