The high-frequency(HF)communication,commonly covering the frequency range between 3 and30MHz,is an effective and important long-distance communication approach.Using the ionosphere as a natural high altitude reflector...The high-frequency(HF)communication,commonly covering the frequency range between 3 and30MHz,is an effective and important long-distance communication approach.Using the ionosphere as a natural high altitude reflector,trans-horizon HF radio transmission is possible with advantages such as high mobility,convenient deployment,strong survivability and展开更多
Science fiction takes many forms, including academic work that calls on readers to think about social and cultural problems. This paper takes a piece of science fiction, Kirinyaga: A Fable of Utopia, as an example and...Science fiction takes many forms, including academic work that calls on readers to think about social and cultural problems. This paper takes a piece of science fiction, Kirinyaga: A Fable of Utopia, as an example and discusses the conflicts among globalization, modernization and tradition present in the text, thus highlighting the academic meaning of science fiction as a literary form.展开更多
The relationship between science fiction and science popularization has long been a controversial issue.Based on a brief historical review of the development of science fiction and science popularization in China, thi...The relationship between science fiction and science popularization has long been a controversial issue.Based on a brief historical review of the development of science fiction and science popularization in China, this paper analyses related literature and concepts and argues that the science–literature dispute can be somewhat lessened in that science fiction can be incorporated into science popularization under the framework of general science popularization.展开更多
The various definitions of science fiction reflect different understandings of science and fantasy and their relationship. Through a review of the development history of the British and American definitions of science...The various definitions of science fiction reflect different understandings of science and fantasy and their relationship. Through a review of the development history of the British and American definitions of science fiction and related controversies, we find that changes in science fiction's definition are often accompanied by the reorientation and reimagination of its position in society and culture. As people's perceptions deepen, the shifting boundary between science and fantasy has important implications for a better understanding of science fiction.展开更多
The proliferation of robot accounts on social media platforms has posed a significant negative impact,necessitating robust measures to counter network anomalies and safeguard content integrity.Social robot detection h...The proliferation of robot accounts on social media platforms has posed a significant negative impact,necessitating robust measures to counter network anomalies and safeguard content integrity.Social robot detection has emerged as a pivotal yet intricate task,aimed at mitigating the dissemination of misleading information.While graphbased approaches have attained remarkable performance in this realm,they grapple with a fundamental limitation:the homogeneity assumption in graph convolution allows social robots to stealthily evade detection by mingling with genuine human profiles.To unravel this challenge and thwart the camouflage tactics,this work proposed an innovative social robot detection framework based on enhanced HOmogeneity and Random Forest(HORFBot).At the core of HORFBot lies a homogeneous graph enhancement strategy,intricately woven with edge-removal techniques,tometiculously dissect the graph intomultiple revealing subgraphs.Subsequently,leveraging the power of contrastive learning,the proposed methodology meticulously trains multiple graph convolutional networks,each honed to discern nuances within these tailored subgraphs.The culminating stage involves the fusion of these feature-rich base classifiers,harmoniously aggregating their insights to produce a comprehensive detection outcome.Extensive experiments on three social robot detection datasets have shown that this method effectively improves the accuracy of social robot detection and outperforms comparative methods.展开更多
String validation routines have been widely used in many real-world applications,such as email validation and postcode validation.String test cases are adopted to test these validation routines,to identify potential d...String validation routines have been widely used in many real-world applications,such as email validation and postcode validation.String test cases are adopted to test these validation routines,to identify potential defects and security risks.Random Testing(RT)is a well-known testing approach to randomly generate string test cases from the input domain(i.e.,the set of all possible test inputs),which is simple to implement at a low cost.However,its testing effectiveness may be unsatisfactory for string validation routines.The main reason for this is that RT may have a high probability to generate invalid rather than valid string test cases,due to its randomness property.This research proposes a new RT approach based on the output types(i.e.,valid and invalid strings)for string validation routines,namely Output-type-guided Random Testing(RTO),which attempts to randomly generate both valid and invalid string test cases with a certain probability.This research performed an empirical study involving several real-world string validation routines collected from ten Java open-source projects,to investigate and compare testing performances of RT-O against the previous two widely-used RT methods.The results show that the generated string test cases by RT-O outperform test cases generated by other RT methods.展开更多
Traffic encryption techniques facilitate cyberattackers to hide their presence and activities.Traffic classification is an important method to prevent network threats.However,due to the tremendous traffic volume and l...Traffic encryption techniques facilitate cyberattackers to hide their presence and activities.Traffic classification is an important method to prevent network threats.However,due to the tremendous traffic volume and limitations of computing,most existing traffic classification techniques are inapplicable to the high-speed network environment.In this paper,we propose a High-speed Encrypted Traffic Classification(HETC)method containing two stages.First,to efficiently detect whether traffic is encrypted,HETC focuses on randomly sampled short flows and extracts aggregation entropies with chi-square test features to measure the different patterns of the byte composition and distribution between encrypted and unencrypted flows.Second,HETC introduces binary features upon the previous features and performs fine-grained traffic classification by combining these payload features with a Random Forest model.The experimental results show that HETC can achieve a 94%F-measure in detecting encrypted flows and a 85%–93%F-measure in classifying fine-grained flows for a 1-KB flow-length dataset,outperforming the state-of-the-art comparison methods.Meanwhile,HETC does not need to wait for the end of the flow and can extract mass computing features.The average time for HETC to process each flow is only 2 or 16 ms,which is lower than the flow duration in most cases,making it a good candidate for high-speed traffic classification.展开更多
Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always cre...Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always credible in practice.Some studies have applied cryptography tools to solve this problem by distributing trust,but they ignore the existence of collusion.In this paper,a blockchain-based Privacy-Preserving and Collusion-Resistant scheme(PPCR)for double auctions is proposed by employing both cryptography and blockchain technology,which is the first decentralized and collusion-resistant double auction scheme that guarantees bidder anonymity and bid privacy.A two-server-based auction framework is designed to support off-chain allocation with privacy preservation and on-chain dispute resolution for collusion resistance.A Dispute Resolution agreement(DR)is provided to the auctioneer to prove that they have conducted the auction correctly and the result is fair and correct.In addition,a Concise Dispute Resolution protocol(CDR)is designed to handle situations where the number of accused winners is small,significantly reducing the computation cost of dispute resolution.Extensive experimental results confirm that PPCR can indeed achieve efficient collusion resistance and verifiability of auction results with low on-chain and off-chain computational overhead.展开更多
This reconnaissance study was carried out in urgency as residents complained of groundwater contamination in a tribal stretch infectedwith chronic kidney disease of unknown etiology in central India where at least 100...This reconnaissance study was carried out in urgency as residents complained of groundwater contamination in a tribal stretch infectedwith chronic kidney disease of unknown etiology in central India where at least 100 people have already died and more than 300 hospitalized.Multi-indexing techniques were used to evaluate groundwater quality for drinking,irrigation,and industrial purposes.The comprehensive water quality index(CWQI)classifies∼52%of the 27 collected samples suitable for drinking,and∼37%partially suitable pending certain treatment.While the relative abundance of chemical parameters stands at Ca^(2+)>Na^(+)>Mg^(2+)>K^(+)for cations and HCO_(3)^(−)>Cl^(−)>NO_(3)^(−)>SO_(4)^(2−)>F^(−)for anions,the groundwater in the area suffers from general hardness,nitrate,and fluoride contamination.It is hypothesized that fluoride ions possibly couplewith excess alkaline earth elements and anions to form metal-complexes inviting Hofmeister phenomena to act in the human kidneys through ingested groundwater.For agricultural water quality assessment,historically developed 10 irrigation indices have been used that classify most groundwater samples suitable for agriculture.Corrosivity indices reveal that the groundwater has moderate to high corrosive affinity.Although the results of the irrigation and corrosivity indices are coherent with CWQI water classes,the use of so many indices based on certain chemical parameters to evaluate water samples for agricultural purposes delivers mixed results and confuses workers about the actual water quality in the field.This calls for the development of a new,robust,and comprehensive standard for appraisal of irrigation water quality that could be used uniformly worldwide.展开更多
The bandwidth resources allocation strategies of the existing Internet of Vehicles(IoV) are mainly base on the communication architecture of the traditional 802.11 x in the wireless local area network(WLAN). The tradi...The bandwidth resources allocation strategies of the existing Internet of Vehicles(IoV) are mainly base on the communication architecture of the traditional 802.11 x in the wireless local area network(WLAN). The traditional communication architecture of IoV will easily cause significant delay and low Packet Delivery Ratio(PDR) for disseminating critical security beacons under the condition of high-speed movement, distance-varying communication, and mixed traffic. This paper proposes a novel bandwidth-link resources cooperative allocation strategy to achieve better communication performance under the road conditions of intelligent transportation systems(ITS). Firstly, in traffic scenarios, based on the characteristic to predict the relative position of the mobile transceivers, a strategy is developed to cooperate on the mobile cellular network and the Dedicated Short-Range Communications(DSRC). Secondly, by adopting the general network simulator NS3, the dedicated mobile channel models that are suitable for the data interaction of ITS, is applied to confirm the feasibility and reliability of the strategy. Finally, by the simulation, comparison, and analysis of some critical performance parame-ters, we conclude that the novel strategy does not only reduce the system delay but also improve the other communication performance indicators, such as the PDR and communication capacity.展开更多
With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic （TEM） method is f...With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic （TEM） method is favorable for prospecting conductive layers because of the coupling relationship between its field structure and formation. However, the shielding effect of conductive overburden would not only require a longer observation time when prospecting the same depth but also weaken the anomalous response of underlying layers. Through direct time domain numerical simulation and horizontal layered earth forward modeling, this paper estimates the length of observation time required to prospect the target, and the distinguishable criterion of multilayer water-filled goal is presented with observation error according to the effect of noise on observation data. The observed emf curves from Dazigou Coal Mine, Shanxi Province can distinguish multilayer water-filled goaf. In quantitative inversion interpretation of observed curves, using electric logging data as initial parameters restrains the equivalence caused by coal formation thin layers. The deduced three-layer and two-layer water-filled goals are confirmed by the drilling hole. The result suggests that when observation time is long enough and with the anomalous situation of underlying layers being greater than the observation error, the use of the central loop TEM method to orosoect a multilaver water-filled goaf is feasible.展开更多
With the rapid development of software technology, software vulnerability has become a major threat to computer security. The timely detection and repair of potential vulnerabilities in software, are of great signific...With the rapid development of software technology, software vulnerability has become a major threat to computer security. The timely detection and repair of potential vulnerabilities in software, are of great significance in reducing system crashes and maintaining system security and integrity. This paper focuses on detecting three common types of vulnerabilities: Unused_Variable, Use_of_Uninitialized_Variable, and Use_After_ Free. We propose a method for software vulnerability detection based on an improved control flow graph(ICFG) and several predicates of vulnerability properties for each type of vulnerability. We also define a set of grammar rules for analyzing and deriving the three mentioned types of vulnerabilities, and design three vulnerability detection algorithms to guide the process of vulnerability detection. In addition, we conduct cases studies of the three mentioned types of vulnerabilities with real vulnerability program segments from Common Weakness Enumeration(CWE). The results of the studies show that the proposed method can detect the vulnerability in the tested program segments. Finally, we conduct manual analysis and experiments on detecting the three types of vulnerability program segments(30 examples for each type) from CWE, to compare the vulnerability detection effectiveness of the proposed method with that of the existing detection tool Cpp Check. The results show that the proposed method performs better. In summary, the method proposed in this paper has certain feasibility and effectiveness in detecting the three mentioned types of vulnerabilities, and it will also have guiding significance for the detection of other common vulnerabilities.展开更多
Abdominal organ segmentation is the segregation of a single or multiple abdominal organ(s) into semantic image segments of pixels identified with homogeneous features such as color and texture, and intensity. The abdo...Abdominal organ segmentation is the segregation of a single or multiple abdominal organ(s) into semantic image segments of pixels identified with homogeneous features such as color and texture, and intensity. The abdominal organ(s) condition is mostly connected with greater morbidity and mortality. Most patients often have asymptomatic abdominal conditions and symptoms, which are often recognized late;hence the abdomen has been the third most common cause of damage to the human body. That notwithstanding,there may be improved outcomes where the condition of an abdominal organ is detected earlier. Over the years, supervised and semi-supervised machine learning methods have been used to segment abdominal organ(s) in order to detect the organ(s) condition. The supervised methods perform well when the used training data represents the target data, but the methods require large manually annotated data and have adaptation problems. The semi-supervised methods are fast but record poor performance than the supervised if assumptions about the data fail to hold. Current state-of-the-art methods of supervised segmentation are largely based on deep learning techniques due to their good accuracy and success in real world applications. Though it requires a large amount of training data for automatic feature extraction, deep learning can hardly be used. As regards the semi-supervised methods of segmentation, self-training and graph-based techniques have attracted much research attention. Self-training can be used with any classifier but does not have a mechanism to rectify mistakes early. Graph-based techniques thrive on their convexity, scalability, and effectiveness in application but have an out-of-sample problem. In this review paper, a study has been carried out on supervised and semi-supervised methods of performing abdominal organ segmentation. An observation of the current approaches, connection and gaps are identified, and prospective future research opportunities are enumerated.展开更多
The integrated modular avionics （IMA） architecture is an open standard in avionics industry, in which the number of functionalities implemented by software is greater than ever before. In the IMA architecture, the r...The integrated modular avionics （IMA） architecture is an open standard in avionics industry, in which the number of functionalities implemented by software is greater than ever before. In the IMA architecture, the reliability of the avionics system is highly affected by the software applications. In order to enhance the fault tolerance feature with regard to software application failures, many industrial standards propose a layered health monitoring/fault management （HM/FM） scheme to periodically check the health status of software application processes and recover the malfunctioning software process whenever an error is located. In this paper, we make an analytical study of the HM/FM system for avionics application software. We use the stochastic Petri nets （SPN） to build a formal model of each component and present a method to combine the components together to form a complete system model with respect to three interlayer query strategies. We further investigate the effectiveness of these strategies in an illustrative system.展开更多
In a millimeter-wave(mmWave)Massive multiple-input multiple-output(MIMO)systems,full-digital beamforming(i.e.,connecting each antenna with a specific radio-frequency(RF)chain)becomes inefficient due to the hardware co...In a millimeter-wave(mmWave)Massive multiple-input multiple-output(MIMO)systems,full-digital beamforming(i.e.,connecting each antenna with a specific radio-frequency(RF)chain)becomes inefficient due to the hardware cost and power consumption.Therefore,hybrid analog and digital transceiver where the number of RF chains are much smaller than that of the antennas has drawn great research interest.In this work,we investigate the use of low-resolution analog-to-digital converters(ADCs)in the uplink of multi-user hybrid and full-digital mmWave Massive MIMO systems.To be specific,we compare the performance of full-digital minimum mean square error(MMSE)and hybrid MMSE beamforming in both sum rates and energy efficiency.Accurate approximations of sum rates and energy efficiency are provided for both schemes,which captures the dominant factors.The analytical results show that full-digital beamforming outperforms hybrid beamforming in terms of sum rates and requires only a small portion(γ)of antennas used by hybrid beamforming to achieve the same sum rates.We given sufficient condition for full-digital beamforming to outperform hybrid beamforming in terms of energy efficiency.Moreover,an algorithm is proposed to search for the optimal ADC resolution bits.Numerical results demonstrate the correctness of the analysis.展开更多
Most of the data publishing methods have not considered sensitivity protection,and hence the adversary can disclose privacy by sensitivity attack.Faced with this problem,this paper presents a medical data publishing m...Most of the data publishing methods have not considered sensitivity protection,and hence the adversary can disclose privacy by sensitivity attack.Faced with this problem,this paper presents a medical data publishing method based on sensitivity determination.To protect the sensitivity,the sensitivity of disease information is determined by semantics.To seek the trade-off between information utility and privacy security,the new method focusses on the protection of sensitive values with high sensitivity and assigns the highly sensitive disease information to groups as evenly as possible.The experiments are conducted on two real-world datasets,of which the records include various attributes of patients.To measure sensitivity protection,the authors define a metric,which can evaluate the degree of sensitivity disclosure.Besides,additional information loss and discernability metrics are used to measure the availability of released tables.The experimental results indicate that the new method can provide better privacy than the traditional one while the information utility is guaranteed.Besides value protection,the proposed method can provide sensitivity protection and available releasing for medical data.展开更多
Driven by the continuous penetration of high data rate services and applications,a large amount of unregulated visible light spectrum is used for communication to fully meet the needs of 6th generation(6G)mobile techn...Driven by the continuous penetration of high data rate services and applications,a large amount of unregulated visible light spectrum is used for communication to fully meet the needs of 6th generation(6G)mobile technologies.Visible light communication(VLC)faces many challenges as a solution that complements existing radio frequency(RF)networks.This paper studies the optimal configuration of LEDs in indoor environments under the constraints of illumination and quality of experience(QoE).Based on the Voronoi tessellation(VT)and centroidal Voronoi tessellation(CVT)theory,combined with the Lloyd’s algorithm,we propose two approaches for optimizing LED deployments to meet the illumination and QoE requirements of all users.Focusing on(i)the minimization of the number of LEDs to be installed in order to meet illumination and average QoE constraints,and(ii)the maximization of the average QoE of users to be served with a fixed number of LEDs.Monte Carlo simulations are carried out for different user distribution compared with hexagonal,square and VT deployment.The simulation results illustrate that under the same conditions,the proposed deployment approach can provide less LEDs and achieve better QoE performance.展开更多
A feedback control model of lattice hydrodynamic model is proposed by taking the information of the historic optimal velocity into account for the traffic system. The modern control theory is applied for the linear st...A feedback control model of lattice hydrodynamic model is proposed by taking the information of the historic optimal velocity into account for the traffic system. The modern control theory is applied for the linear stability condition with feedback control signal. The result shows that the stability of traffic flow is closely related to the information of the historic optimal velocity. Furthermore, numerical simulations conform that the new feedback control did increase the stability of traffic flow efficiently, which is in accord with theoretical analysis.展开更多
In head mounted display(HMD),in order to cancel pincushion distortion,the images displayed on the mobile should be prewarped with barrel distortion.The copyright of the mobile video should be verified on both the orig...In head mounted display(HMD),in order to cancel pincushion distortion,the images displayed on the mobile should be prewarped with barrel distortion.The copyright of the mobile video should be verified on both the original view and the pre-warped virtual view.A robust watermarking resistant against barrel distortion for HMDs is proposed in this paper.Watermark mask is embedded into image in consideration of imperceptibility and robustness of watermarking.In order to detect watermark from the pre-warped image with barrel distortion,an estimation method of the barrel distortion is proposed for HMDs.Then,the same warp is enforced on the embedded watermark mask with the estimated parameters of barrel distortion.The correlation between the warped watermark and the pre-warped image is computed to predicate the existence of watermark.As shown in experimental results,watermark of mobile video can be detected not only from the original views,but also from the pre-warped virtual view.It also shows that the proposed scheme is resistant against combined barrel distortion and common post-processing,such as JPEG compression.展开更多
文摘The high-frequency(HF)communication,commonly covering the frequency range between 3 and30MHz,is an effective and important long-distance communication approach.Using the ionosphere as a natural high altitude reflector,trans-horizon HF radio transmission is possible with advantages such as high mobility,convenient deployment,strong survivability and
文摘Science fiction takes many forms, including academic work that calls on readers to think about social and cultural problems. This paper takes a piece of science fiction, Kirinyaga: A Fable of Utopia, as an example and discusses the conflicts among globalization, modernization and tradition present in the text, thus highlighting the academic meaning of science fiction as a literary form.
文摘The relationship between science fiction and science popularization has long been a controversial issue.Based on a brief historical review of the development of science fiction and science popularization in China, this paper analyses related literature and concepts and argues that the science–literature dispute can be somewhat lessened in that science fiction can be incorporated into science popularization under the framework of general science popularization.
基金supported by the 2022 Science Popularization Enhancement Programme for Master’s and PhD Students funded by the China Association for Science and Technology:‘A Historiographical Study of the Definition of Science Fiction and Debates Involved’(grant no.KXYJS2022003)
文摘The various definitions of science fiction reflect different understandings of science and fantasy and their relationship. Through a review of the development history of the British and American definitions of science fiction and related controversies, we find that changes in science fiction's definition are often accompanied by the reorientation and reimagination of its position in society and culture. As people's perceptions deepen, the shifting boundary between science and fantasy has important implications for a better understanding of science fiction.
基金Funds for the Central Universities(grant number CUC24SG018).
文摘The proliferation of robot accounts on social media platforms has posed a significant negative impact,necessitating robust measures to counter network anomalies and safeguard content integrity.Social robot detection has emerged as a pivotal yet intricate task,aimed at mitigating the dissemination of misleading information.While graphbased approaches have attained remarkable performance in this realm,they grapple with a fundamental limitation:the homogeneity assumption in graph convolution allows social robots to stealthily evade detection by mingling with genuine human profiles.To unravel this challenge and thwart the camouflage tactics,this work proposed an innovative social robot detection framework based on enhanced HOmogeneity and Random Forest(HORFBot).At the core of HORFBot lies a homogeneous graph enhancement strategy,intricately woven with edge-removal techniques,tometiculously dissect the graph intomultiple revealing subgraphs.Subsequently,leveraging the power of contrastive learning,the proposed methodology meticulously trains multiple graph convolutional networks,each honed to discern nuances within these tailored subgraphs.The culminating stage involves the fusion of these feature-rich base classifiers,harmoniously aggregating their insights to produce a comprehensive detection outcome.Extensive experiments on three social robot detection datasets have shown that this method effectively improves the accuracy of social robot detection and outperforms comparative methods.
基金supported by the Science and Technology Development Fund of Macao,Macao SAR(Nos.0021/2023/RIA1 and 0046/2021/A)a Faculty Research Grant of Macao University of Science and Technology(No.FRG-22-103-FIE)supported by the National Natural Science Foundation of China(Nos.61872167 and 61502205).
文摘String validation routines have been widely used in many real-world applications,such as email validation and postcode validation.String test cases are adopted to test these validation routines,to identify potential defects and security risks.Random Testing(RT)is a well-known testing approach to randomly generate string test cases from the input domain(i.e.,the set of all possible test inputs),which is simple to implement at a low cost.However,its testing effectiveness may be unsatisfactory for string validation routines.The main reason for this is that RT may have a high probability to generate invalid rather than valid string test cases,due to its randomness property.This research proposes a new RT approach based on the output types(i.e.,valid and invalid strings)for string validation routines,namely Output-type-guided Random Testing(RTO),which attempts to randomly generate both valid and invalid string test cases with a certain probability.This research performed an empirical study involving several real-world string validation routines collected from ten Java open-source projects,to investigate and compare testing performances of RT-O against the previous two widely-used RT methods.The results show that the generated string test cases by RT-O outperform test cases generated by other RT methods.
基金supported by the National Natural Science Foundation of China under Grant No.U1736216。
文摘Traffic encryption techniques facilitate cyberattackers to hide their presence and activities.Traffic classification is an important method to prevent network threats.However,due to the tremendous traffic volume and limitations of computing,most existing traffic classification techniques are inapplicable to the high-speed network environment.In this paper,we propose a High-speed Encrypted Traffic Classification(HETC)method containing two stages.First,to efficiently detect whether traffic is encrypted,HETC focuses on randomly sampled short flows and extracts aggregation entropies with chi-square test features to measure the different patterns of the byte composition and distribution between encrypted and unencrypted flows.Second,HETC introduces binary features upon the previous features and performs fine-grained traffic classification by combining these payload features with a Random Forest model.The experimental results show that HETC can achieve a 94%F-measure in detecting encrypted flows and a 85%–93%F-measure in classifying fine-grained flows for a 1-KB flow-length dataset,outperforming the state-of-the-art comparison methods.Meanwhile,HETC does not need to wait for the end of the flow and can extract mass computing features.The average time for HETC to process each flow is only 2 or 16 ms,which is lower than the flow duration in most cases,making it a good candidate for high-speed traffic classification.
基金supported by the National Key R&D Program of China (No.2020YFB1005500)the Leading-edge Technology Program of Jiangsu Natural Science Foundation (No.BK20202001)+1 种基金the Fundamental Research Funds for the Central Universities (No.XJSJ23040)the Postdoctoral Science Foundation of Jiangsu Province (No.2021K596C)。
文摘Electronic auctions(e-auctions)remove the physical limitations of traditional auctions and bring this mechanism to the general public.However,most e-auction schemes involve a trusted auctioneer,which is not always credible in practice.Some studies have applied cryptography tools to solve this problem by distributing trust,but they ignore the existence of collusion.In this paper,a blockchain-based Privacy-Preserving and Collusion-Resistant scheme(PPCR)for double auctions is proposed by employing both cryptography and blockchain technology,which is the first decentralized and collusion-resistant double auction scheme that guarantees bidder anonymity and bid privacy.A two-server-based auction framework is designed to support off-chain allocation with privacy preservation and on-chain dispute resolution for collusion resistance.A Dispute Resolution agreement(DR)is provided to the auctioneer to prove that they have conducted the auction correctly and the result is fair and correct.In addition,a Concise Dispute Resolution protocol(CDR)is designed to handle situations where the number of accused winners is small,significantly reducing the computation cost of dispute resolution.Extensive experimental results confirm that PPCR can indeed achieve efficient collusion resistance and verifiability of auction results with low on-chain and off-chain computational overhead.
文摘This reconnaissance study was carried out in urgency as residents complained of groundwater contamination in a tribal stretch infectedwith chronic kidney disease of unknown etiology in central India where at least 100 people have already died and more than 300 hospitalized.Multi-indexing techniques were used to evaluate groundwater quality for drinking,irrigation,and industrial purposes.The comprehensive water quality index(CWQI)classifies∼52%of the 27 collected samples suitable for drinking,and∼37%partially suitable pending certain treatment.While the relative abundance of chemical parameters stands at Ca^(2+)>Na^(+)>Mg^(2+)>K^(+)for cations and HCO_(3)^(−)>Cl^(−)>NO_(3)^(−)>SO_(4)^(2−)>F^(−)for anions,the groundwater in the area suffers from general hardness,nitrate,and fluoride contamination.It is hypothesized that fluoride ions possibly couplewith excess alkaline earth elements and anions to form metal-complexes inviting Hofmeister phenomena to act in the human kidneys through ingested groundwater.For agricultural water quality assessment,historically developed 10 irrigation indices have been used that classify most groundwater samples suitable for agriculture.Corrosivity indices reveal that the groundwater has moderate to high corrosive affinity.Although the results of the irrigation and corrosivity indices are coherent with CWQI water classes,the use of so many indices based on certain chemical parameters to evaluate water samples for agricultural purposes delivers mixed results and confuses workers about the actual water quality in the field.This calls for the development of a new,robust,and comprehensive standard for appraisal of irrigation water quality that could be used uniformly worldwide.
基金supported in part by the National Natural Science Foundation of China (No.61573171)the Major Information Projects of State Ministry of Transportation (No.2013-364-836-900)
文摘The bandwidth resources allocation strategies of the existing Internet of Vehicles(IoV) are mainly base on the communication architecture of the traditional 802.11 x in the wireless local area network(WLAN). The traditional communication architecture of IoV will easily cause significant delay and low Packet Delivery Ratio(PDR) for disseminating critical security beacons under the condition of high-speed movement, distance-varying communication, and mixed traffic. This paper proposes a novel bandwidth-link resources cooperative allocation strategy to achieve better communication performance under the road conditions of intelligent transportation systems(ITS). Firstly, in traffic scenarios, based on the characteristic to predict the relative position of the mobile transceivers, a strategy is developed to cooperate on the mobile cellular network and the Dedicated Short-Range Communications(DSRC). Secondly, by adopting the general network simulator NS3, the dedicated mobile channel models that are suitable for the data interaction of ITS, is applied to confirm the feasibility and reliability of the strategy. Finally, by the simulation, comparison, and analysis of some critical performance parame-ters, we conclude that the novel strategy does not only reduce the system delay but also improve the other communication performance indicators, such as the PDR and communication capacity.
基金supported by the National Science Foundation of China(No.41374129)Science and Technology Project of Shanxi Province(No.20100321066)Research and Development Project of National Major Scientifi c Research Equipment(No.ZDYZ2012-1-05-04)
文摘With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic （TEM） method is favorable for prospecting conductive layers because of the coupling relationship between its field structure and formation. However, the shielding effect of conductive overburden would not only require a longer observation time when prospecting the same depth but also weaken the anomalous response of underlying layers. Through direct time domain numerical simulation and horizontal layered earth forward modeling, this paper estimates the length of observation time required to prospect the target, and the distinguishable criterion of multilayer water-filled goal is presented with observation error according to the effect of noise on observation data. The observed emf curves from Dazigou Coal Mine, Shanxi Province can distinguish multilayer water-filled goaf. In quantitative inversion interpretation of observed curves, using electric logging data as initial parameters restrains the equivalence caused by coal formation thin layers. The deduced three-layer and two-layer water-filled goals are confirmed by the drilling hole. The result suggests that when observation time is long enough and with the anomalous situation of underlying layers being greater than the observation error, the use of the central loop TEM method to orosoect a multilaver water-filled goaf is feasible.
基金Supported by the National Natural Science Foundation of China(61202110 and 61502205)the Project of Jiangsu Provincial Six Talent Peaks(XYDXXJS-016)
文摘With the rapid development of software technology, software vulnerability has become a major threat to computer security. The timely detection and repair of potential vulnerabilities in software, are of great significance in reducing system crashes and maintaining system security and integrity. This paper focuses on detecting three common types of vulnerabilities: Unused_Variable, Use_of_Uninitialized_Variable, and Use_After_ Free. We propose a method for software vulnerability detection based on an improved control flow graph(ICFG) and several predicates of vulnerability properties for each type of vulnerability. We also define a set of grammar rules for analyzing and deriving the three mentioned types of vulnerabilities, and design three vulnerability detection algorithms to guide the process of vulnerability detection. In addition, we conduct cases studies of the three mentioned types of vulnerabilities with real vulnerability program segments from Common Weakness Enumeration(CWE). The results of the studies show that the proposed method can detect the vulnerability in the tested program segments. Finally, we conduct manual analysis and experiments on detecting the three types of vulnerability program segments(30 examples for each type) from CWE, to compare the vulnerability detection effectiveness of the proposed method with that of the existing detection tool Cpp Check. The results show that the proposed method performs better. In summary, the method proposed in this paper has certain feasibility and effectiveness in detecting the three mentioned types of vulnerabilities, and it will also have guiding significance for the detection of other common vulnerabilities.
基金supported by National Natural Science Foundation of China(Nos.61772242,61976106 and 61572239)the China Postdoctoral Science Foundation(No.2017M611737)+1 种基金the Six Talent Peaks Project in Jiangsu Province(No.DZXX-122)the Key Special Project of Health and Family Planning Science and Technology in Zhenjiang City(No.SHW2017019)。
文摘Abdominal organ segmentation is the segregation of a single or multiple abdominal organ(s) into semantic image segments of pixels identified with homogeneous features such as color and texture, and intensity. The abdominal organ(s) condition is mostly connected with greater morbidity and mortality. Most patients often have asymptomatic abdominal conditions and symptoms, which are often recognized late;hence the abdomen has been the third most common cause of damage to the human body. That notwithstanding,there may be improved outcomes where the condition of an abdominal organ is detected earlier. Over the years, supervised and semi-supervised machine learning methods have been used to segment abdominal organ(s) in order to detect the organ(s) condition. The supervised methods perform well when the used training data represents the target data, but the methods require large manually annotated data and have adaptation problems. The semi-supervised methods are fast but record poor performance than the supervised if assumptions about the data fail to hold. Current state-of-the-art methods of supervised segmentation are largely based on deep learning techniques due to their good accuracy and success in real world applications. Though it requires a large amount of training data for automatic feature extraction, deep learning can hardly be used. As regards the semi-supervised methods of segmentation, self-training and graph-based techniques have attracted much research attention. Self-training can be used with any classifier but does not have a mechanism to rectify mistakes early. Graph-based techniques thrive on their convexity, scalability, and effectiveness in application but have an out-of-sample problem. In this review paper, a study has been carried out on supervised and semi-supervised methods of performing abdominal organ segmentation. An observation of the current approaches, connection and gaps are identified, and prospective future research opportunities are enumerated.
基金supported by the National Grand Fundamental Research Program of China (Nos. 2010CB328105, 2009CB320504)the Tsinghua University Initiative Scientific Research Programthe National Natural Science Foundation of China (Nos. 61070182,60973107, 60973144, 61173008, 61070021)
文摘The integrated modular avionics （IMA） architecture is an open standard in avionics industry, in which the number of functionalities implemented by software is greater than ever before. In the IMA architecture, the reliability of the avionics system is highly affected by the software applications. In order to enhance the fault tolerance feature with regard to software application failures, many industrial standards propose a layered health monitoring/fault management （HM/FM） scheme to periodically check the health status of software application processes and recover the malfunctioning software process whenever an error is located. In this paper, we make an analytical study of the HM/FM system for avionics application software. We use the stochastic Petri nets （SPN） to build a formal model of each component and present a method to combine the components together to form a complete system model with respect to three interlayer query strategies. We further investigate the effectiveness of these strategies in an illustrative system.
基金supported in part by the Key Research&Development Plan of Jiangsu Province(No.BE2018108)National Nature Science Foundation of China(Nos.61701198&61772243)+3 种基金Nature Science Foundation of Jiangsu Province(No.BK20170557)Nature Science Foundation for Higher Education Institutions of Jiangsu Province of China(No.17KJB510009)the open research fund of National Mobile Communications Research Laboratory,Southeast University(No.2018D13)Young Talent Project of Jiangsu University and Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX18_0742)
文摘In a millimeter-wave(mmWave)Massive multiple-input multiple-output(MIMO)systems,full-digital beamforming(i.e.,connecting each antenna with a specific radio-frequency(RF)chain)becomes inefficient due to the hardware cost and power consumption.Therefore,hybrid analog and digital transceiver where the number of RF chains are much smaller than that of the antennas has drawn great research interest.In this work,we investigate the use of low-resolution analog-to-digital converters(ADCs)in the uplink of multi-user hybrid and full-digital mmWave Massive MIMO systems.To be specific,we compare the performance of full-digital minimum mean square error(MMSE)and hybrid MMSE beamforming in both sum rates and energy efficiency.Accurate approximations of sum rates and energy efficiency are provided for both schemes,which captures the dominant factors.The analytical results show that full-digital beamforming outperforms hybrid beamforming in terms of sum rates and requires only a small portion(γ)of antennas used by hybrid beamforming to achieve the same sum rates.We given sufficient condition for full-digital beamforming to outperform hybrid beamforming in terms of energy efficiency.Moreover,an algorithm is proposed to search for the optimal ADC resolution bits.Numerical results demonstrate the correctness of the analysis.
基金supported by the National Natural Science Foundation of China(No.62062016)Doctoral research start‐up fund of Guangxi Normal University(RZ1900006676)Guangxi project of improving Middleaged/Young teachers'ability(No.2020KY020323)。
文摘Most of the data publishing methods have not considered sensitivity protection,and hence the adversary can disclose privacy by sensitivity attack.Faced with this problem,this paper presents a medical data publishing method based on sensitivity determination.To protect the sensitivity,the sensitivity of disease information is determined by semantics.To seek the trade-off between information utility and privacy security,the new method focusses on the protection of sensitive values with high sensitivity and assigns the highly sensitive disease information to groups as evenly as possible.The experiments are conducted on two real-world datasets,of which the records include various attributes of patients.To measure sensitivity protection,the authors define a metric,which can evaluate the degree of sensitivity disclosure.Besides,additional information loss and discernability metrics are used to measure the availability of released tables.The experimental results indicate that the new method can provide better privacy than the traditional one while the information utility is guaranteed.Besides value protection,the proposed method can provide sensitivity protection and available releasing for medical data.
基金This work was supported by National Natural Science Foundation of China(No.61772243)Jiangsu Provincial Key Research and Development Program(BE2018108)Six talent peak high level talent plan projects of Jiangsu Province(XYDXX-115).
文摘Driven by the continuous penetration of high data rate services and applications,a large amount of unregulated visible light spectrum is used for communication to fully meet the needs of 6th generation(6G)mobile technologies.Visible light communication(VLC)faces many challenges as a solution that complements existing radio frequency(RF)networks.This paper studies the optimal configuration of LEDs in indoor environments under the constraints of illumination and quality of experience(QoE).Based on the Voronoi tessellation(VT)and centroidal Voronoi tessellation(CVT)theory,combined with the Lloyd’s algorithm,we propose two approaches for optimizing LED deployments to meet the illumination and QoE requirements of all users.Focusing on(i)the minimization of the number of LEDs to be installed in order to meet illumination and average QoE constraints,and(ii)the maximization of the average QoE of users to be served with a fixed number of LEDs.Monte Carlo simulations are carried out for different user distribution compared with hexagonal,square and VT deployment.The simulation results illustrate that under the same conditions,the proposed deployment approach can provide less LEDs and achieve better QoE performance.
基金Supported by the National Natural Science Foundation of China under Grant No.61673168
文摘A feedback control model of lattice hydrodynamic model is proposed by taking the information of the historic optimal velocity into account for the traffic system. The modern control theory is applied for the linear stability condition with feedback control signal. The result shows that the stability of traffic flow is closely related to the information of the historic optimal velocity. Furthermore, numerical simulations conform that the new feedback control did increase the stability of traffic flow efficiently, which is in accord with theoretical analysis.
基金partially supported by Fundamental Research Funds for the Central Universities of China(2016JKF01203)National Natural Science Foundation of China(61401408,61402484,and 61502160)
文摘In head mounted display(HMD),in order to cancel pincushion distortion,the images displayed on the mobile should be prewarped with barrel distortion.The copyright of the mobile video should be verified on both the original view and the pre-warped virtual view.A robust watermarking resistant against barrel distortion for HMDs is proposed in this paper.Watermark mask is embedded into image in consideration of imperceptibility and robustness of watermarking.In order to detect watermark from the pre-warped image with barrel distortion,an estimation method of the barrel distortion is proposed for HMDs.Then,the same warp is enforced on the embedded watermark mask with the estimated parameters of barrel distortion.The correlation between the warped watermark and the pre-warped image is computed to predicate the existence of watermark.As shown in experimental results,watermark of mobile video can be detected not only from the original views,but also from the pre-warped virtual view.It also shows that the proposed scheme is resistant against combined barrel distortion and common post-processing,such as JPEG compression.
