Latent fingerprints are the unintentional impressions found at the crime scenes and are considered crucial evidence in criminal identification.Law enforcement and forensic agencies have been using latent fingerprints ...Latent fingerprints are the unintentional impressions found at the crime scenes and are considered crucial evidence in criminal identification.Law enforcement and forensic agencies have been using latent fingerprints as testimony in courts.However,since the latent fingerprints are accidentally leftover on different surfaces,the lifted prints look inferior.Therefore,a tremendous amount of research is being carried out in automatic latent fingerprint identification to improve the overall fingerprint recognition performance.As a result,there is an ever-growing demand to develop reliable and robust systems.In this regard,we present a comprehensive literature review of the existing methods utilized in latent fingerprint acquisition,segmentation,quality assessment,enhancement,feature extraction,and matching steps.Later,we provide insight into different benchmark latent datasets available to perform research in this area.Our study highlights various research challenges and gaps by performing detailed analysis on the existing state-of-the-art segmentation,enhancement,extraction,and matching approaches to strengthen the research.展开更多
When the face of the inspected person and the photograph on their identification(ID)card cannot be clearly matched,the individual is undocumented,or the ID is forged,it is often difficult for the on‑site police to res...When the face of the inspected person and the photograph on their identification(ID)card cannot be clearly matched,the individual is undocumented,or the ID is forged,it is often difficult for the on‑site police to respond in time.This study proposes a number of key technologies for collecting fingerprints at mobile terminals for fast comparison using an automated fingerprint ID system(AFIS).These technologies ensure intelligent mobile fingerprint collection and allow the transmission of fingerprint information from the terminal to AFIS,over a wireless public security network for real‑time fingerprint comparison.This study also analyzes the feasibility and effectiveness of the proposed technologies for system design and the applicability of fingerprint ID algorithms.The system achieved good results in a test by the Shanghai Public Security Bureau Criminal Investigation Corps.展开更多
As the first individualization-information processing equipment put into practical service worldwide,Automated Fingerprint Identification System(AFIS)has always been regarded as the first choice in individualization o...As the first individualization-information processing equipment put into practical service worldwide,Automated Fingerprint Identification System(AFIS)has always been regarded as the first choice in individualization of criminal suspects or those who died in mass disasters.By integrating data within the existing regional large-scale AFIS database,many countries are constructing an ultra large state-of-the-art AFIS(or Imperial Scale AFIS)system.Therefore,it is very important to develop a series of ten-print data quality controlling process for this system of this type,which would insure a substantial matching efficiency,as the pouring data come into this imperial scale being.As the image quality of ten-print data is closely relevant to AFIS matching proficiency,a lot of police departments have allocated huge amount of human and financial resources over this issue by carrying out manual verification works for years.Unfortunately,quality control method above is always proved to be inadequate because it is an astronomical task involved,in which it has always been problematic and less affiant for potential errors.Hence,we will implement quality control in the above procedure with supplementary-acquisition effect caused by the delay of feedback instructions sent from the human verification teams.In this article,a series of fingerprint image quality supervising techniques has been put forward,which makes it possible for computer programs to supervise the ten-print image quality in real-time and more accurate manner as substitute for traditional manual verifications.Besides its prominent advantages in the human and financial expenditures,it has also been proved to obviously improve the image quality of the AFIS ten-print database,which leads up to a dramatic improvement in the AFIS-matching accuracy as well.展开更多
Fingerprint has been widely used in a variety of biometric identification systems in the past several years due to its uniqueness and immutability. With the rapid development of fingerprint identification techniques, ...Fingerprint has been widely used in a variety of biometric identification systems in the past several years due to its uniqueness and immutability. With the rapid development of fingerprint identification techniques, many fingerprint identification systems are in urgent need to deal with large-scale fingerprint storage and high concurrent recognition queries, which bring huge challenges to the system. In this circumstance, we design and implement a distributed and load-balancing fingerprint identification system named Pegasus, which includes a distributed feature extraction subsystem and a distributed feature storage subsystem. The feature extraction procedure combines the Hadoop Image Processing Interface(HIPI) library to enhance its overall processing speed; the feature storage subsystem optimizes MongoD B's default load balance strategy to improve the efficiency and robustness of Pegasus.Experiments and simulations are carried out, and results show that Pegasus can reduce the time cost by 70% during the feature extraction procedure. Pegasus also balances the difference of access load among front-end mongos nodes to less than 5%. Additionally, Pegasus reduces over 40% of data migration among back-end data shards to obtain a more reasonable data distribution based on the operation load(insertion, deletion, update, and query) of each shard.展开更多
In recent years,oil spill accidents occur frequently in the marine area of China.Finding out the spilled oil source is a key step in the relevant investigation.In this paper,a step-by-step fingerprinting identificatio...In recent years,oil spill accidents occur frequently in the marine area of China.Finding out the spilled oil source is a key step in the relevant investigation.In this paper,a step-by-step fingerprinting identification method was used in a spilled oil accident in the Bohai Sea in 2002.Advanced chemical fingerprinting and data interpretation techniques were used to characterize the chemical composition and determine the possible sources of two spilled oil samples.The original gas chromatography -flame ionization detec-tion (GC-FID) chromatogram of saturated hydrocarbons was compared.The gas chromatography-mass spectrometry (GC/MS) chromatograms of aromatic hydrocarbons terpane and sterane,n-alkane and poly-aromatic hydrocarbons (PAHs) were analyzed.The correlation analysis on diagnostic ratios was performed with Student’s t-test.It is found that the oil fingerprinting of the spilled oil (designated as sz1) from the polluted sand beach was identical with the suspected oil (designated as ky1) from a nearby crude oil refinery factory.They both showed the fingerprinting character of mixed oil.The oil fingerprinting of the spilled oil (designated as ms1) collected from the port was significantly different from oil ky1 and oil sz1 and was with a lubricating oil fingerprint character.The identification result not only gave support for the spilled oil investigation,but also served as an example for studying spilled oil accidents.展开更多
By gas chromatogram, six crude oils fingerprinting distributed in four oilfields and four oil platforms were analyzed and the corre- sponding normal paraffin hydrocarbon ( including pristane and phytane) concentrati...By gas chromatogram, six crude oils fingerprinting distributed in four oilfields and four oil platforms were analyzed and the corre- sponding normal paraffin hydrocarbon ( including pristane and phytane) concentration was obtained by the internal standard methed. The normal paraffin hydrocarbon distribution patterns of six crude oils were built and compared. The cluster analysis on the normal paraffin hydrocarbon concentration was conducted for classification and some ratios of oils were used for oils comparison. The results indicated: there was a clear difference within different crude oils in different oil fields and a small difference between the crude oils in the same oil platform. The normal paraffin hydrocarbon distribution pattern and ratios, as well as the cluster analysis on the nomad paraffin hydrocarbon concentration can have a better differentiation result for the crude oils with small difference than the original gas chromatogram.展开更多
Fingerprint image is a typical non-restraint image that has some uncertainty, which makes it difficult to perform identification using classical approach. Therefore, fuzzy pattern recognition is applied to match indiv...Fingerprint image is a typical non-restraint image that has some uncertainty, which makes it difficult to perform identification using classical approach. Therefore, fuzzy pattern recognition is applied to match individual query by searching the entire template database. The fuzzy maximum subordinate principle is used to solve shift matching. Through experimenting and analyzing, the approximate principle fuzzy method is employed by selecting fuzzy characteristics and determining the similarity function to achieve the further accuracy. Theoretical and experimental results show this approach is effective and reasonable.展开更多
An embedded method which can provide privacy-safeguard and data-security layer for the Personal Health Records (PHR) is proposed. In our method, the fingerprint image of a patient or doctor is obtained with fingerprin...An embedded method which can provide privacy-safeguard and data-security layer for the Personal Health Records (PHR) is proposed. In our method, the fingerprint image of a patient or doctor is obtained with fingerprint scanner and the values of fingerprint features points are calculated and saved in an IC card. As a result, saving the fingerprint image is not required in our method. Based on the user's password, a transformation is applied on the fingerprint topology structural values. After that, we take these points' coordinates on the transformed topology structure as a cryptographic key, which is used with Advanced Encryption Standard (AES) algorithm to encrypt the users' privacy information, such as prescription, laboratory sheet, medical certificate, etc. The experimental results demonstrate that our method could bring patients the self-control and self-management on their own medical privacy information.展开更多
We developed a computerized seed identification system. Fifteen rice varietiesthat were widely used in China were analyzed by AFLP fingerprinting. 12 primerpairs were screened, In order to simplify the procedure and c...We developed a computerized seed identification system. Fifteen rice varietiesthat were widely used in China were analyzed by AFLP fingerprinting. 12 primerpairs were screened, In order to simplify the procedure and cut down the cost inseed identification. the least number of primer pairs for practical seed identifi-cation should be seleeled. In this study. 3 primer pairs were selected. They展开更多
We have developed a microwave-assisted hydrothermal method,where both microwave and hydrothermal techniques are utilized to synthesize CdTe nanocrystals with high quality in less than 55 s.Among the known preparation ...We have developed a microwave-assisted hydrothermal method,where both microwave and hydrothermal techniques are utilized to synthesize CdTe nanocrystals with high quality in less than 55 s.Among the known preparation methods,the monodisperse CdTe nanocrystals showing narrow emission spectra,widest scope of emission peak(from 500 nm to 822 nm) and high quantum yield(up to 80%) were synthesized by this route.The quantum yield of CdTe with near-infrared emission(800 nm) is up to 10%,which is better than that of InAs(0.5%―2%) synthesized in organic phase.Moreover,we detected the latent fingerprints on aluminum,plastic,glass and papers by prepared CdTe nanocrystals,and photoluminescence fingerprints images were taken with a digital camera.Then the images would transmitt into fingerprint detection system of computer to identify the criminals in suit.展开更多
The mobility of the targets asks for high requirements of the locating speed in indoor positioning systems.The standard medium access control(MAC)algorithm will often cause lots of packet conflicts and high transmissi...The mobility of the targets asks for high requirements of the locating speed in indoor positioning systems.The standard medium access control(MAC)algorithm will often cause lots of packet conflicts and high transmission delay if multiple users communicate with one beacon at the same time,which will severely limit the speed of the system.Therefore,an optimized MAC algorithm is proposed based on channel reservation to enable users to reserve beacons.A frame threshold is set to ensure the users with shorter data frames do not depend on the reservation mechanism,and multiple users can achieve packets switching with relative beacon in a fixed sequence by using frequency division multiplexing technology.The simulation results show that the optimized MAC algorithm proposed in this paper can improve the positioning speed significantly while maintaining the positioning accuracy.Moreover,the positioning accuracy can be increased to a certain extent if more channel resources can be obtained,so as to provide effective technical support for the location and tracking applications of indoor moving targets.展开更多
With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological tech...With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological technology can be better accepted and used by the public. In this paper, we propose a novel quantum bit(qbit)-based scheme to solve the security and privacy problem existing in the traditional fingerprint identification system. By exploiting the properties of quantum mechanics, our proposed scheme, cancelable remote quantum fingerprint templates protection scheme, can achieve the unconditional security guaranteed in an information-theoretical sense. Moreover, this novel quantum scheme can invalidate most of the attacks aimed at the fingerprint identification system. In addition, the proposed scheme is applicable to the requirement of remote communication with no need to worry about its security and privacy during the transmission. This is an absolute advantage when comparing with other traditional methods. Security analysis shows that the proposed scheme can effectively ensure the communication security and the privacy of users' information for the fingerprint identification.展开更多
Red emissive carbon dots(CDs)powder was synthesized on a large scale from phloroglucinol and boric acid by a novel solid state reaction with yield up to 75%.This method is safe and convenient,for it needs neither high...Red emissive carbon dots(CDs)powder was synthesized on a large scale from phloroglucinol and boric acid by a novel solid state reaction with yield up to 75%.This method is safe and convenient,for it needs neither high pressure reactors nor complicated post-treatment procedures.The as-prepared carbon dots powder exhibited strong red fluorescence with excitation-independent behavior.XPS measurement and PL spectra suggest that such red fluorescence arise from boron-doped structures in CDs,which increases along with the boron concentration on CDs surface but decreases when the concentration quenching effect takes place.To overcome the aggregation induced fluorescence quenching of the solid CDs powder,the conventional methods are dispersing CDs into a large amount of inert substrates.But our present work provides a new strategy to realize strong red fluorescence of CDs in solid state.As a result,such carbon dots powder works well for latent fingerprint identification on various material surfaces.展开更多
The fingerprint identification technology has been developed and applied effectively to security systems in financial transactions,personal information security,national security,and other fields.In this paper,we prop...The fingerprint identification technology has been developed and applied effectively to security systems in financial transactions,personal information security,national security,and other fields.In this paper,we proposed the development of a fingerprint identification system based on image processing methods that clarify fingerprint contours,using machine learning methods to increase processing speed and increase the accuracy of the fingerprint identification process.The identification system consists of the following main steps:improving image quality and image segmentation to identify the fingerprint area,extracting features,and matching the database.The accuracy of the system reached 97.75%on the mixed high-and low-quality fingerprint database.展开更多
Laterally reversed(mirrored)fingerprints are difficult to detect by applying routine search procedures.One suggestion to avoid errors when dealing with probable reversals is to perform comparisons with both direct and...Laterally reversed(mirrored)fingerprints are difficult to detect by applying routine search procedures.One suggestion to avoid errors when dealing with probable reversals is to perform comparisons with both direct and reversed fingerprints.This simple procedure has been applied and led to the detection of two more cases of reversed fingerprint usage in fake documents.In one of the reported cases,experts found on the web the same fingerprints used by criminals in fake documents.This finding is important because it indicates that matched fingerprints do not necessarily link different criminal cases.展开更多
Fingerprint identification is one of the most important biometric authentication methods. However, current devices for recording digital fingerprints can only capture plain-touch fingerprints. Rolled fingerprints hav...Fingerprint identification is one of the most important biometric authentication methods. However, current devices for recording digital fingerprints can only capture plain-touch fingerprints. Rolled fingerprints have much more information for recognition, so a method is needed to construct a rolled fingerprint from a series of plain-touch fingerprints. This paper presents a novel algorithm for image mosaicing for real time rolled fingerprint construction in which the images are assembled with corrections to create a smooth, non-fragmented rolled fingerprint in real time. Experimental results demonstrate its effectiveness by comparing it with other conventional algorithms.展开更多
The interpretation of fingerprint evidence depends on the judgments of fingerprint examiners.This study assessed the accuracy of different judgments made by fingerprint examiners following the Analysis,Comparison,and ...The interpretation of fingerprint evidence depends on the judgments of fingerprint examiners.This study assessed the accuracy of different judgments made by fingerprint examiners following the Analysis,Comparison,and Evaluation(ACE)process.Each examiner was given five marks for analysis,comparison,and evaluation.We compared the experts’judgments against the ground truth and used an annotation platform to evaluate how Chinese fingerprint examiners document their comparisons during the identification process.The results showed that different examiners demonstrated different accuracy of judgments and different mechanisms to reach them.展开更多
To ensure the safety of infrastructure users,the long-term skid resistance is a crucial factor and is determined in large by the mineralogical and morphological characteristics of surfacing aggregate.Most studies have...To ensure the safety of infrastructure users,the long-term skid resistance is a crucial factor and is determined in large by the mineralogical and morphological characteristics of surfacing aggregate.Most studies have investigated these aggregate properties separately without considering the interrelation between one another.The objective of this study is to consider the morphological characteristics as well as the mineralogical fingerprint of aggregate to develop an innovative approach to optimize the aggregate selection process.The investigations are based on 11 different aggregate types with a broad range of mineralogy,commonly used in Germany.The long-term influence of polishing and wearing on the surface aggregate was simulated by means of the Aachen Polishing Machine and the MicroDeval test respectively.To evaluate the impact of these tests,the aggregate shape was characterized by means of an imaging system called Aggregate Image Measurement System while the skid resistance of aggregates was evaluated with the British Pendulum Test.The test results show that the quartz and calcite are the key crystals to determine the anti-wear resistance of aggregates.A correlation between the skid resistance,morphological properties and mineralogy is derived,which proves the mineralogical fingerprint technology is practical for characterization of aggregates used in pavement surface layers.展开更多
文摘Latent fingerprints are the unintentional impressions found at the crime scenes and are considered crucial evidence in criminal identification.Law enforcement and forensic agencies have been using latent fingerprints as testimony in courts.However,since the latent fingerprints are accidentally leftover on different surfaces,the lifted prints look inferior.Therefore,a tremendous amount of research is being carried out in automatic latent fingerprint identification to improve the overall fingerprint recognition performance.As a result,there is an ever-growing demand to develop reliable and robust systems.In this regard,we present a comprehensive literature review of the existing methods utilized in latent fingerprint acquisition,segmentation,quality assessment,enhancement,feature extraction,and matching steps.Later,we provide insight into different benchmark latent datasets available to perform research in this area.Our study highlights various research challenges and gaps by performing detailed analysis on the existing state-of-the-art segmentation,enhancement,extraction,and matching approaches to strengthen the research.
文摘When the face of the inspected person and the photograph on their identification(ID)card cannot be clearly matched,the individual is undocumented,or the ID is forged,it is often difficult for the on‑site police to respond in time.This study proposes a number of key technologies for collecting fingerprints at mobile terminals for fast comparison using an automated fingerprint ID system(AFIS).These technologies ensure intelligent mobile fingerprint collection and allow the transmission of fingerprint information from the terminal to AFIS,over a wireless public security network for real‑time fingerprint comparison.This study also analyzes the feasibility and effectiveness of the proposed technologies for system design and the applicability of fingerprint ID algorithms.The system achieved good results in a test by the Shanghai Public Security Bureau Criminal Investigation Corps.
基金The authors gratefully acknowledge the support of the Swiss National Science Foundation(through grant No.IZ32Z0_l68366)the University of Lausanne,and the support of the Collaborative Innovation Center of Judicial Civilization,China.And the authors also gratefully acknowledge the support of Liaoning Provincial Police Key Scientific Research Proj ect(through grant No.2016LNKJJH01)China Ministry of Public Safety Key Scientific Research Project(through grant No.2016JSYJAO1).
文摘As the first individualization-information processing equipment put into practical service worldwide,Automated Fingerprint Identification System(AFIS)has always been regarded as the first choice in individualization of criminal suspects or those who died in mass disasters.By integrating data within the existing regional large-scale AFIS database,many countries are constructing an ultra large state-of-the-art AFIS(or Imperial Scale AFIS)system.Therefore,it is very important to develop a series of ten-print data quality controlling process for this system of this type,which would insure a substantial matching efficiency,as the pouring data come into this imperial scale being.As the image quality of ten-print data is closely relevant to AFIS matching proficiency,a lot of police departments have allocated huge amount of human and financial resources over this issue by carrying out manual verification works for years.Unfortunately,quality control method above is always proved to be inadequate because it is an astronomical task involved,in which it has always been problematic and less affiant for potential errors.Hence,we will implement quality control in the above procedure with supplementary-acquisition effect caused by the delay of feedback instructions sent from the human verification teams.In this article,a series of fingerprint image quality supervising techniques has been put forward,which makes it possible for computer programs to supervise the ten-print image quality in real-time and more accurate manner as substitute for traditional manual verifications.Besides its prominent advantages in the human and financial expenditures,it has also been proved to obviously improve the image quality of the AFIS ten-print database,which leads up to a dramatic improvement in the AFIS-matching accuracy as well.
基金Project supported by the National Basic Research Program(973)of China(No.2014CB340303) the National Natural Science Foundation of China(Nos.61222205 and 61402490)+1 种基金 the Program for New Century Excellent Talents in University,China(No.141066) the Fok Ying-Tong Education Foundation
文摘Fingerprint has been widely used in a variety of biometric identification systems in the past several years due to its uniqueness and immutability. With the rapid development of fingerprint identification techniques, many fingerprint identification systems are in urgent need to deal with large-scale fingerprint storage and high concurrent recognition queries, which bring huge challenges to the system. In this circumstance, we design and implement a distributed and load-balancing fingerprint identification system named Pegasus, which includes a distributed feature extraction subsystem and a distributed feature storage subsystem. The feature extraction procedure combines the Hadoop Image Processing Interface(HIPI) library to enhance its overall processing speed; the feature storage subsystem optimizes MongoD B's default load balance strategy to improve the efficiency and robustness of Pegasus.Experiments and simulations are carried out, and results show that Pegasus can reduce the time cost by 70% during the feature extraction procedure. Pegasus also balances the difference of access load among front-end mongos nodes to less than 5%. Additionally, Pegasus reduces over 40% of data migration among back-end data shards to obtain a more reasonable data distribution based on the operation load(insertion, deletion, update, and query) of each shard.
文摘In recent years,oil spill accidents occur frequently in the marine area of China.Finding out the spilled oil source is a key step in the relevant investigation.In this paper,a step-by-step fingerprinting identification method was used in a spilled oil accident in the Bohai Sea in 2002.Advanced chemical fingerprinting and data interpretation techniques were used to characterize the chemical composition and determine the possible sources of two spilled oil samples.The original gas chromatography -flame ionization detec-tion (GC-FID) chromatogram of saturated hydrocarbons was compared.The gas chromatography-mass spectrometry (GC/MS) chromatograms of aromatic hydrocarbons terpane and sterane,n-alkane and poly-aromatic hydrocarbons (PAHs) were analyzed.The correlation analysis on diagnostic ratios was performed with Student’s t-test.It is found that the oil fingerprinting of the spilled oil (designated as sz1) from the polluted sand beach was identical with the suspected oil (designated as ky1) from a nearby crude oil refinery factory.They both showed the fingerprinting character of mixed oil.The oil fingerprinting of the spilled oil (designated as ms1) collected from the port was significantly different from oil ky1 and oil sz1 and was with a lubricating oil fingerprint character.The identification result not only gave support for the spilled oil investigation,but also served as an example for studying spilled oil accidents.
基金the National Natural Science Foundation of China under contract No.49976027 the Important Topic of Scientific Research of the State 0ceanic Administration, China, on the construction system of oil fingerprinting database and the key technology (from 2004 to 2005 ).
文摘By gas chromatogram, six crude oils fingerprinting distributed in four oilfields and four oil platforms were analyzed and the corre- sponding normal paraffin hydrocarbon ( including pristane and phytane) concentration was obtained by the internal standard methed. The normal paraffin hydrocarbon distribution patterns of six crude oils were built and compared. The cluster analysis on the normal paraffin hydrocarbon concentration was conducted for classification and some ratios of oils were used for oils comparison. The results indicated: there was a clear difference within different crude oils in different oil fields and a small difference between the crude oils in the same oil platform. The normal paraffin hydrocarbon distribution pattern and ratios, as well as the cluster analysis on the nomad paraffin hydrocarbon concentration can have a better differentiation result for the crude oils with small difference than the original gas chromatogram.
文摘Fingerprint image is a typical non-restraint image that has some uncertainty, which makes it difficult to perform identification using classical approach. Therefore, fuzzy pattern recognition is applied to match individual query by searching the entire template database. The fuzzy maximum subordinate principle is used to solve shift matching. Through experimenting and analyzing, the approximate principle fuzzy method is employed by selecting fuzzy characteristics and determining the similarity function to achieve the further accuracy. Theoretical and experimental results show this approach is effective and reasonable.
文摘An embedded method which can provide privacy-safeguard and data-security layer for the Personal Health Records (PHR) is proposed. In our method, the fingerprint image of a patient or doctor is obtained with fingerprint scanner and the values of fingerprint features points are calculated and saved in an IC card. As a result, saving the fingerprint image is not required in our method. Based on the user's password, a transformation is applied on the fingerprint topology structural values. After that, we take these points' coordinates on the transformed topology structure as a cryptographic key, which is used with Advanced Encryption Standard (AES) algorithm to encrypt the users' privacy information, such as prescription, laboratory sheet, medical certificate, etc. The experimental results demonstrate that our method could bring patients the self-control and self-management on their own medical privacy information.
文摘We developed a computerized seed identification system. Fifteen rice varietiesthat were widely used in China were analyzed by AFLP fingerprinting. 12 primerpairs were screened, In order to simplify the procedure and cut down the cost inseed identification. the least number of primer pairs for practical seed identifi-cation should be seleeled. In this study. 3 primer pairs were selected. They
基金Supported by the National Natural Science Foundation of China(Nos.20775076 and 20875084)the National Technology Research & Development Program in the 11th Five-Year Plan of China(No.2006BAK10B09)
文摘We have developed a microwave-assisted hydrothermal method,where both microwave and hydrothermal techniques are utilized to synthesize CdTe nanocrystals with high quality in less than 55 s.Among the known preparation methods,the monodisperse CdTe nanocrystals showing narrow emission spectra,widest scope of emission peak(from 500 nm to 822 nm) and high quantum yield(up to 80%) were synthesized by this route.The quantum yield of CdTe with near-infrared emission(800 nm) is up to 10%,which is better than that of InAs(0.5%―2%) synthesized in organic phase.Moreover,we detected the latent fingerprints on aluminum,plastic,glass and papers by prepared CdTe nanocrystals,and photoluminescence fingerprints images were taken with a digital camera.Then the images would transmitt into fingerprint detection system of computer to identify the criminals in suit.
基金Supported by the National Natural Science Foundation of China(No.61771186)Outstanding Youth Project of Heilongjiang Natural Science Foundation(No.YQ2020F012)Undergraduate University Project of Young Scientist Creative Talent of Heilongjiang Province(No.UNPYSCT-2017125)。
文摘The mobility of the targets asks for high requirements of the locating speed in indoor positioning systems.The standard medium access control(MAC)algorithm will often cause lots of packet conflicts and high transmission delay if multiple users communicate with one beacon at the same time,which will severely limit the speed of the system.Therefore,an optimized MAC algorithm is proposed based on channel reservation to enable users to reserve beacons.A frame threshold is set to ensure the users with shorter data frames do not depend on the reservation mechanism,and multiple users can achieve packets switching with relative beacon in a fixed sequence by using frequency division multiplexing technology.The simulation results show that the optimized MAC algorithm proposed in this paper can improve the positioning speed significantly while maintaining the positioning accuracy.Moreover,the positioning accuracy can be increased to a certain extent if more channel resources can be obtained,so as to provide effective technical support for the location and tracking applications of indoor moving targets.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61379153 and 61572529)
文摘With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological technology can be better accepted and used by the public. In this paper, we propose a novel quantum bit(qbit)-based scheme to solve the security and privacy problem existing in the traditional fingerprint identification system. By exploiting the properties of quantum mechanics, our proposed scheme, cancelable remote quantum fingerprint templates protection scheme, can achieve the unconditional security guaranteed in an information-theoretical sense. Moreover, this novel quantum scheme can invalidate most of the attacks aimed at the fingerprint identification system. In addition, the proposed scheme is applicable to the requirement of remote communication with no need to worry about its security and privacy during the transmission. This is an absolute advantage when comparing with other traditional methods. Security analysis shows that the proposed scheme can effectively ensure the communication security and the privacy of users' information for the fingerprint identification.
基金financially supported by the National Natural Science Foundation of China(Nos.21975048,21771039)the Science and Technology Commission of Shanghai Municipality(No.19DZ2270100)。
文摘Red emissive carbon dots(CDs)powder was synthesized on a large scale from phloroglucinol and boric acid by a novel solid state reaction with yield up to 75%.This method is safe and convenient,for it needs neither high pressure reactors nor complicated post-treatment procedures.The as-prepared carbon dots powder exhibited strong red fluorescence with excitation-independent behavior.XPS measurement and PL spectra suggest that such red fluorescence arise from boron-doped structures in CDs,which increases along with the boron concentration on CDs surface but decreases when the concentration quenching effect takes place.To overcome the aggregation induced fluorescence quenching of the solid CDs powder,the conventional methods are dispersing CDs into a large amount of inert substrates.But our present work provides a new strategy to realize strong red fluorescence of CDs in solid state.As a result,such carbon dots powder works well for latent fingerprint identification on various material surfaces.
基金This research was supported by the National Natural Science Foundation of China(Nos.00001 and 00010)Chongqing Municipal Education Commission(No.KJ120616).
文摘The fingerprint identification technology has been developed and applied effectively to security systems in financial transactions,personal information security,national security,and other fields.In this paper,we proposed the development of a fingerprint identification system based on image processing methods that clarify fingerprint contours,using machine learning methods to increase processing speed and increase the accuracy of the fingerprint identification process.The identification system consists of the following main steps:improving image quality and image segmentation to identify the fingerprint area,extracting features,and matching the database.The accuracy of the system reached 97.75%on the mixed high-and low-quality fingerprint database.
文摘Laterally reversed(mirrored)fingerprints are difficult to detect by applying routine search procedures.One suggestion to avoid errors when dealing with probable reversals is to perform comparisons with both direct and reversed fingerprints.This simple procedure has been applied and led to the detection of two more cases of reversed fingerprint usage in fake documents.In one of the reported cases,experts found on the web the same fingerprints used by criminals in fake documents.This finding is important because it indicates that matched fingerprints do not necessarily link different criminal cases.
文摘Fingerprint identification is one of the most important biometric authentication methods. However, current devices for recording digital fingerprints can only capture plain-touch fingerprints. Rolled fingerprints have much more information for recognition, so a method is needed to construct a rolled fingerprint from a series of plain-touch fingerprints. This paper presents a novel algorithm for image mosaicing for real time rolled fingerprint construction in which the images are assembled with corrections to create a smooth, non-fragmented rolled fingerprint in real time. Experimental results demonstrate its effectiveness by comparing it with other conventional algorithms.
文摘The interpretation of fingerprint evidence depends on the judgments of fingerprint examiners.This study assessed the accuracy of different judgments made by fingerprint examiners following the Analysis,Comparison,and Evaluation(ACE)process.Each examiner was given five marks for analysis,comparison,and evaluation.We compared the experts’judgments against the ground truth and used an annotation platform to evaluate how Chinese fingerprint examiners document their comparisons during the identification process.The results showed that different examiners demonstrated different accuracy of judgments and different mechanisms to reach them.
基金supported by the National Key Research and Development Program of China(2019YFE0116300)National Natural Science Foundation of China(52250610218)+3 种基金Natural Science Foundation of Heilongjiang Province of China(JJ2020ZD0015)Opening Project Fund of Materials Service Safety Assessment Facilities(MSAF-2021-005)National Key Research and Development Program of China(2018YFB1600100)the German Research Foundation(OE 514/15-1(Project ID 459436571))。
文摘To ensure the safety of infrastructure users,the long-term skid resistance is a crucial factor and is determined in large by the mineralogical and morphological characteristics of surfacing aggregate.Most studies have investigated these aggregate properties separately without considering the interrelation between one another.The objective of this study is to consider the morphological characteristics as well as the mineralogical fingerprint of aggregate to develop an innovative approach to optimize the aggregate selection process.The investigations are based on 11 different aggregate types with a broad range of mineralogy,commonly used in Germany.The long-term influence of polishing and wearing on the surface aggregate was simulated by means of the Aachen Polishing Machine and the MicroDeval test respectively.To evaluate the impact of these tests,the aggregate shape was characterized by means of an imaging system called Aggregate Image Measurement System while the skid resistance of aggregates was evaluated with the British Pendulum Test.The test results show that the quartz and calcite are the key crystals to determine the anti-wear resistance of aggregates.A correlation between the skid resistance,morphological properties and mineralogy is derived,which proves the mineralogical fingerprint technology is practical for characterization of aggregates used in pavement surface layers.