In the archive of the Ground Wide Angle Camera(GWAC),we found 43 white light flares from 43 stars,among which,three are sympathetic or homologous flares,and one of them also has a quasi-periodic pulsation with a perio...
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In the archive of the Ground Wide Angle Camera(GWAC),we found 43 white light flares from 43 stars,among which,three are sympathetic or homologous flares,and one of them also has a quasi-periodic pulsation with a period of 13.0±1.5 *** these 43 flare stars,there are 19 new active stars and 41 stars that have available TESS and/or K2 light curves,from which we found 931 stellar *** also obtained rotational or orbital periods of 34 GWAC flare stars,of which 33 are less than 5.4 days,and ephemerides of three eclipsing binaries from these light *** with low resolution spectra from LAMOST and the Xinglong 2.16 m telescope,we found that L_(Hα)/L_(bol) are in the saturation region in the rotation-activity *** the LAMOST medium-resolution spectrum,we found that Star#3(HAT 178-02667)has double Hαemissions which imply it is a binary,and two components are both active *** stars have flare frequency distributions(FFDs)from TESS and/or K2 light *** FFDs show that the flares detected by GWAC can occur at a frequency of 0.5to 9.5 yr^(-1).The impact of flares on habitable planets was also studied based on these FFDs,and flares from some GWAC flare stars may produce enough energetic flares to destroy ozone layers,but none can trigger prebiotic chemistry on their habitable planets.
Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using a...
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Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction *** the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management ***,an audio-based location distinction method is designed to detect the position change of the ***,the audio frequency response(AFR)of several frequency points is utilized as a device *** device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different *** on the features above,amovement detection algorithmfor device identification and location distinction is ***,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and *** experiments are conducted to evaluate the performance of the proposed *** experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.
In the archive of the Ground Wide Angle Camera (GWAC), we found 43 white light flares from 43 stars, among which, three are sympathetic or homologous flares, and one of them also has a quasi-periodic pulsation with a ...
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The basic concept of smart environment is to be aware of the context information related to environmental and human behavioral changes, and to provide appropriate services accordingly. To obtain the context informatio...
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The basic concept of smart environment is to be aware of the context information related to environmental and human behavioral changes, and to provide appropriate services accordingly. To obtain the context informatio...
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The basic concept of smart environment is to be aware of the context information related to environmental and human behavioral changes, and to provide appropriate services accordingly. To obtain the context information, people often use video cameras, microphones, and other devices. These devices can obtain a wealth of environmental information, but could easily lead to privacy issues. Large environmental information also need more computing resources to process the information. In this paper, we study human behavior identification based on simple sensors. Using fuzzy logic we analyze the sensor data and try to identify four different activities. Experimental results show that the proposed method can correctly identify 83.7 % of these four activities. Results given here will be useful for designing smart homes, smart office, and so on.
Text classification is the key technology for topic tracking, and vector space model (VSM) is one of the most simple and effective topics representation model. Feature selection algorithm in VSM is an important means ...
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Text classification is the key technology for topic tracking, and vector space model (VSM) is one of the most simple and effective topics representation model. Feature selection algorithm in VSM is an important means of data pre-processing, and it can reduce vector space dimension and improve the generalization ability of the algorithm. Therefore, it is necessary for feature selection algorithms to be in-depth and extensive research. So we develop a topic tracking system to study how feature dimension and the value of K-neighbors affect topic tracking. Then we get the variation law that they affect topic tracking, and add up their optimal values in topic tracking. Finally, TDT evaluation methods prove that optimal topic tracking performance based on adjusting the value of K-neighbors for text increases by 7.246% more than feature dimension.
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