Folklore research entails field trips, serve as secondary role. Writing of title, abstract and while textual study and circumstantial investigation merely keywords for folklore papers differs from that of other types ...Folklore research entails field trips, serve as secondary role. Writing of title, abstract and while textual study and circumstantial investigation merely keywords for folklore papers differs from that of other types of articles. Proceeding from writing strategies and linguistic features, the authors intend to share their experience with fellow researchers.展开更多
The use of high-temperature fuel cells as a power technology can improve the efficiency of electricity generation and achieve near-zero emissions of carbon dioxide.This work explores the performance of a 10 kW high-te...The use of high-temperature fuel cells as a power technology can improve the efficiency of electricity generation and achieve near-zero emissions of carbon dioxide.This work explores the performance of a 10 kW high-temperature molten carbonate fuel cell.The key materials of a single cell were characterized and analyzed using X-ray diffraction and scanning electron microscopy.The results show that the pore size of the key electrode material is 6.5 lm and the matrix material is a-LiAlO_(2).Experimentally,the open circuit voltage of the single cell was found to be 1.23 V.The current density was greater than 100 mA/cm^(2)at an operating voltage of 0.7 V.The 10 kW fuel cell stack comprised 80 single fuel cells with a total area of 2000 cm^(2)and achieved an open circuit voltage of greater than 85 V.The fuel cell stack power and current density could reach 11.7 kW and 104.5 mA/cm2 at an operating voltage of 56 V.The influence and long-term stable operation of the stack were also analyzed and discussed.The successful operation of a 10 kW high-temperature fuel cell promotes the large-scale use of fuel cells and provides a research basis for future investigations of fuel cell capacity enhancement and distributed generation in China.展开更多
Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wirele...Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’uncertainty.However,the physical layer secret key generation(PHY-SKG)depends on two fundamental parameters,i.e.,coherence time and power allocation.The coherence time for PHY-SKG is not applicable to secure wireless channels.This is because coherence time is for a certain period of time.Thus,legitimate users generate the secret keys(SKs)with a shorter key length in size.Hence,an attacker can quickly get information about the SKs.Consequently,the attacker can easily get valuable information from authentic users.Therefore,we considered the scheme of power allocation to enhance the secret key generation rate(SKGR)between legitimate users.Hence,we propose an alternative method,i.e.,a power allocation,to improve the SKGR.Our results show 72%higher SKGR in bits/sec by increasing power transmission.In addition,the power transmission is based on two important parameters,i.e.,epsilon and power loss factor,as given in power transmission equations.We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR.The SKGR is approximately 40.7%greater at 250 from 50 mW at epsilon=1.The value of SKGR is reduced to 18.5%at 250 mW when epsilonis 0.5.Furthermore,the transmission power is also measured against the different power loss factor values,i.e.,3.5,3,and 2.5,respectively,at epsilon=0.5.Hence,it is concluded that the value of epsilon and power loss factor impacts power transmission and,consequently,impacts the SKGR.展开更多
The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness,...The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.展开更多
This paper presents an improved simple power attack against the key schedule of Camellia. While the original attack required an exact determination of the Hamming weight of intermediate data values based on power meas...This paper presents an improved simple power attack against the key schedule of Camellia. While the original attack required an exact determination of the Hamming weight of intermediate data values based on power measurements, in this paper, two types of the simple power attack are presented and shown to be tolerant of errors that might occur in the Hamming weight determinations. In practical applications of the attack, such errors are likely to occur due to noise and distortion in the power measurements and their mapping to the Hamming weights of the data. To resist these attacks, the required design rationale of key schedules and several practical countermeasures are suggested.展开更多
In the government work report for Two Sessions 2019, key words about E-commerce and internet were mentioned lots of times. This included terms such as Internet+, cross-border E-commerce,industrial internet, digital ec...In the government work report for Two Sessions 2019, key words about E-commerce and internet were mentioned lots of times. This included terms such as Internet+, cross-border E-commerce,industrial internet, digital economy,sharing economy, online and offline consumption, Internet+education and soon.Keywords No.1:Internet+Work Report:1. Internet+was advanced across the board and new technologies and models were used to transform traditional industries. 2. We will speed up efforts to pursue Internet+in all industries and sectors.展开更多
This paper has proposed a new methodology extracting stability classes of field association words depending on automatically power link analysis to enhance the precision of decision tree. In this paper, we have studie...This paper has proposed a new methodology extracting stability classes of field association words depending on automatically power link analysis to enhance the precision of decision tree. In this paper, we have studied the effects of the time variation based on the frequencies of specific words called field association words that connected to documents using power link in a specific period. The stability classes have referred to the popularity of field association words based on the change of time in a given period. The new approach has evaluated by conducting experiments simulating results of 1575 files (about 5.16 MB). Based on these experiments, it has turned out that, the F-measure for ascending, stable and descending classes have achieved 93.6%, 99.8% and 75.7%, respectively. These results mean that F-measure was increasing by 12%, 4% and 34% than traditional methods because of the power link analysis.展开更多
As the scale of the power system continues to expand,the environment for power operations becomes more and more complex.Existing risk management and control methods for power operations can only set the same risk dete...As the scale of the power system continues to expand,the environment for power operations becomes more and more complex.Existing risk management and control methods for power operations can only set the same risk detection standard and conduct the risk detection for any scenario indiscriminately.Therefore,more reliable and accurate security control methods are urgently needed.In order to improve the accuracy and reliability of the operation risk management and control method,this paper proposes a method for identifying the key links in the whole process of electric power operation based on the spatiotemporal hybrid convolutional neural network.To provide early warning and control of targeted risks,first,the video stream is framed adaptively according to the pixel changes in the video stream.Then,the optimized MobileNet is used to extract the feature map of the video stream,which contains both time-series and static spatial scene information.The feature maps are combined and non-linearly mapped to realize the identification of dynamic operating scenes.Finally,training samples and test samples are produced by using the whole process image of a power company in Xinjiang as a case study,and the proposed algorithm is compared with the unimproved MobileNet.The experimental results demonstrated that the method proposed in this paper can accurately identify the type and start and end time of each operation link in the whole process of electric power operation,and has good real-time performance.The average accuracy of the algorithm can reach 87.8%,and the frame rate is 61 frames/s,which is of great significance for improving the reliability and accuracy of security control methods.展开更多
文摘Folklore research entails field trips, serve as secondary role. Writing of title, abstract and while textual study and circumstantial investigation merely keywords for folklore papers differs from that of other types of articles. Proceeding from writing strategies and linguistic features, the authors intend to share their experience with fellow researchers.
基金This project was supported by National Key R&D Program of China(2017YFB0601903)Beijing Science and Technology Commission Technology Collaborative Innovation Project(201100004520001)the Huaneng Clean Energy Institute(TZ-11-SST01-JY-01).
文摘The use of high-temperature fuel cells as a power technology can improve the efficiency of electricity generation and achieve near-zero emissions of carbon dioxide.This work explores the performance of a 10 kW high-temperature molten carbonate fuel cell.The key materials of a single cell were characterized and analyzed using X-ray diffraction and scanning electron microscopy.The results show that the pore size of the key electrode material is 6.5 lm and the matrix material is a-LiAlO_(2).Experimentally,the open circuit voltage of the single cell was found to be 1.23 V.The current density was greater than 100 mA/cm^(2)at an operating voltage of 0.7 V.The 10 kW fuel cell stack comprised 80 single fuel cells with a total area of 2000 cm^(2)and achieved an open circuit voltage of greater than 85 V.The fuel cell stack power and current density could reach 11.7 kW and 104.5 mA/cm2 at an operating voltage of 56 V.The influence and long-term stable operation of the stack were also analyzed and discussed.The successful operation of a 10 kW high-temperature fuel cell promotes the large-scale use of fuel cells and provides a research basis for future investigations of fuel cell capacity enhancement and distributed generation in China.
基金supported by the China National Key R&D Program(No.2018YFB0803600)Natural Science Foundation of China(No.61801008)+3 种基金Scientific Research Common Program of Beijing Municipal Education Commission(No.KM201910005025)the Chinese Postdoctoral Science Foundation(No.2020M670074)Key Project of Hunan Provincial,Department of Education(No.26420A205)The Construct Program of Applied Characteristics Discipline in Hunan University of Science and Engineering.
文摘Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’uncertainty.However,the physical layer secret key generation(PHY-SKG)depends on two fundamental parameters,i.e.,coherence time and power allocation.The coherence time for PHY-SKG is not applicable to secure wireless channels.This is because coherence time is for a certain period of time.Thus,legitimate users generate the secret keys(SKs)with a shorter key length in size.Hence,an attacker can quickly get information about the SKs.Consequently,the attacker can easily get valuable information from authentic users.Therefore,we considered the scheme of power allocation to enhance the secret key generation rate(SKGR)between legitimate users.Hence,we propose an alternative method,i.e.,a power allocation,to improve the SKGR.Our results show 72%higher SKGR in bits/sec by increasing power transmission.In addition,the power transmission is based on two important parameters,i.e.,epsilon and power loss factor,as given in power transmission equations.We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR.The SKGR is approximately 40.7%greater at 250 from 50 mW at epsilon=1.The value of SKGR is reduced to 18.5%at 250 mW when epsilonis 0.5.Furthermore,the transmission power is also measured against the different power loss factor values,i.e.,3.5,3,and 2.5,respectively,at epsilon=0.5.Hence,it is concluded that the value of epsilon and power loss factor impacts power transmission and,consequently,impacts the SKGR.
文摘The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.
基金the National Natural Science Foundation of China (60673072)the Natural Basic Research Program of China (2007CB311201)
文摘This paper presents an improved simple power attack against the key schedule of Camellia. While the original attack required an exact determination of the Hamming weight of intermediate data values based on power measurements, in this paper, two types of the simple power attack are presented and shown to be tolerant of errors that might occur in the Hamming weight determinations. In practical applications of the attack, such errors are likely to occur due to noise and distortion in the power measurements and their mapping to the Hamming weights of the data. To resist these attacks, the required design rationale of key schedules and several practical countermeasures are suggested.
文摘In the government work report for Two Sessions 2019, key words about E-commerce and internet were mentioned lots of times. This included terms such as Internet+, cross-border E-commerce,industrial internet, digital economy,sharing economy, online and offline consumption, Internet+education and soon.Keywords No.1:Internet+Work Report:1. Internet+was advanced across the board and new technologies and models were used to transform traditional industries. 2. We will speed up efforts to pursue Internet+in all industries and sectors.
文摘This paper has proposed a new methodology extracting stability classes of field association words depending on automatically power link analysis to enhance the precision of decision tree. In this paper, we have studied the effects of the time variation based on the frequencies of specific words called field association words that connected to documents using power link in a specific period. The stability classes have referred to the popularity of field association words based on the change of time in a given period. The new approach has evaluated by conducting experiments simulating results of 1575 files (about 5.16 MB). Based on these experiments, it has turned out that, the F-measure for ascending, stable and descending classes have achieved 93.6%, 99.8% and 75.7%, respectively. These results mean that F-measure was increasing by 12%, 4% and 34% than traditional methods because of the power link analysis.
基金This paper is supported by the Science and technology projects of Yunnan Province(Grant No.202202AD080004).
文摘As the scale of the power system continues to expand,the environment for power operations becomes more and more complex.Existing risk management and control methods for power operations can only set the same risk detection standard and conduct the risk detection for any scenario indiscriminately.Therefore,more reliable and accurate security control methods are urgently needed.In order to improve the accuracy and reliability of the operation risk management and control method,this paper proposes a method for identifying the key links in the whole process of electric power operation based on the spatiotemporal hybrid convolutional neural network.To provide early warning and control of targeted risks,first,the video stream is framed adaptively according to the pixel changes in the video stream.Then,the optimized MobileNet is used to extract the feature map of the video stream,which contains both time-series and static spatial scene information.The feature maps are combined and non-linearly mapped to realize the identification of dynamic operating scenes.Finally,training samples and test samples are produced by using the whole process image of a power company in Xinjiang as a case study,and the proposed algorithm is compared with the unimproved MobileNet.The experimental results demonstrated that the method proposed in this paper can accurately identify the type and start and end time of each operation link in the whole process of electric power operation,and has good real-time performance.The average accuracy of the algorithm can reach 87.8%,and the frame rate is 61 frames/s,which is of great significance for improving the reliability and accuracy of security control methods.