Most traffic control systems available in major cities in Cameroon are still out dated, make use of theories and models which are very slow to implement, waste resources and their efficiency is very low. Thus the numb...Most traffic control systems available in major cities in Cameroon are still out dated, make use of theories and models which are very slow to implement, waste resources and their efficiency is very low. Thus the number of road accidents encountered on our major highways and inter urban traffic networks has been increasing despite the various efforts made by government and certain NGO to synthesize road users on certain aspects of traffic control and safety road use. Taxis are not left out in the whole show and most of the blame always falls on them. The need to use available Information and Communication Technology ICT to improve on the control of traffic in inter urban cities and major highways is imperative. ITS optimizes the use of resources, reduce pollution, contribute to environmental protection and increases the national economy. . This paper starts by giving a brief situation of the transportation system in Cameroon, its drawbacks and proposes an optimized ITS based system.展开更多
For conventional optical polarization imaging of underwater target,the polarization degree of backscatter should be pre-measured by averaging the pixel intensities in the no target region of the polarization images,an...For conventional optical polarization imaging of underwater target,the polarization degree of backscatter should be pre-measured by averaging the pixel intensities in the no target region of the polarization images,and the polarization property of the target is assumed to be completely depolarized.When the scattering background is unseen in the field of view or the target is polarized,conventional method is helpless in detecting the target.An improvement is to use lots of co-polarization and cross polarization detection components.We propose a polarization subtraction method to estimate depolarization property of the scattering noise and target signal.And experiment in a quartz cuvette container is performed to demonstrate the effectiveness of the proposed method.The results show that the proposed method can work without scattering background reference,and further recover the target along with smooth surface for polarization preserving response.This study promotes the development of optical polarization imaging systems in underwater environments.展开更多
This paper proposes a distributed control method based on the differential flatness(DF) property of robot swarms. The swarm DF mapping is established for underactuated differentially flat dynamics, according to the co...This paper proposes a distributed control method based on the differential flatness(DF) property of robot swarms. The swarm DF mapping is established for underactuated differentially flat dynamics, according to the control objective. The DF mapping refers to the fact that the system state and input of each robot can be derived algebraically from the flat outputs of the leaders and the cooperative errors and their finite order derivatives. Based on the proposed swarm DF mapping, a distributed controller is designed. The distributed implementation of swarm DF mapping is achieved through observer design. The effectiveness of the proposed method is validated through a numerical simulation of quadrotor swarm synchronization.展开更多
Network storage provides high scalability, availability and flexibility for storage systems, and is widely applied to many fields. Particularly, I/O performance is of great significance. Its application is wide and ex...Network storage provides high scalability, availability and flexibility for storage systems, and is widely applied to many fields. Particularly, I/O performance is of great significance. Its application is wide and expanding rapidly. I/O performance has already become the bottleneck of the whole performance of computer systems for a long time, and under the condition of the present computer technology, I/O performance optimization method looks especially important. In the paper, I/O performance model was analyzed based on the combination of quasi birth, death process and queuing model, and then solved the model. A number of important related performance indicators and the relationship between them were given. By the way of example, this method can show the I/O performance more accurately. Finally, we got some useful conclusions, which may be used to evaluate network storage performance, and are the basis of confirming I/O scheduling strategy.展开更多
Aiming at the problem of merging heterogeneous semantic taxonomy emerged in Web information integration, a method of building Web classification ontology （WCO） has been proposed. A WCO that is logically consistent w...Aiming at the problem of merging heterogeneous semantic taxonomy emerged in Web information integration, a method of building Web classification ontology （WCO） has been proposed. A WCO that is logically consistent with the suggested upper merged ontology （SUMO） is defined, together with axioms needed to classify Web pages. WCO can be used as a foundation of merging heterogeneous semantic taxonomy, and could be used to support Web information integration and classification based Web information retrieval.展开更多
According to the problem of energy consumption in wireless sensor network （WSN）,this paper puts forward a routing optimization algorithm with quality of multi-service, using the function of routing optimization with...According to the problem of energy consumption in wireless sensor network （WSN）,this paper puts forward a routing optimization algorithm with quality of multi-service, using the function of routing optimization with quality of multi-service and membership function of satisfaction, which integrates the energy consumption of communication and residual and the information of time delay into the membership function of satisfaction to solve the equilibrium factor, so that it can become the optimal routing that balances the network lifetime, transmission delay of data, and node energy consumption of nodes. Simulation experiment shows that adopting the algorithm can make lifecycle of nodes longer and network transmit more data packets at the same time. Experimental results verify the algorithm can effectively balance the network energy, reduce the energy consumption and prolong the network lifetime.展开更多
Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in th...Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in this era of technology.Instruction-assisted 3D technology can display stereo graphics and promote students'understanding of the geometrical structure and characteristics of graphics.Spatial ability includes several aspects.Few software programs are available for training different aspects of spatial ability for senior high school students.This study aims to explore an effective method for training the spatial ability for senior high school students,and to promote the development of students'independent inquiry ability.Methods First,an inquiry design strategy to improve the spatial ability of students is proposed.Based on this strategy,unity3D was used to develop a 3D inquiry environment that can use leap motion to complete a gesture interaction.Finally,researchers carried out experience-based activities and issued user experience questionnaires to participants to verify the application effect of the spatial ability inquiry environment and used interviews to understand the user experience of participants exploring the leap motion device in a 3D inquiry environment.Results 32 learners participated in the experiment.learners have a high score for perceived usefulness and willingness to use.Compared with the perceived ease of use and perceived usefulness,the average score of the application effect is relatively low.In terms of willingness to use,most of the learners expressed their willingness to use a similar inquiry environment for spatial ability training in the future.Conclusions The spatial ability inquiry environment can help learners better understand different concepts.The users showed a strong willingness to continue using the device.The device also updates the teaching concept to a certain extent and emphasizes the dominant position of a student.展开更多
Imaging logging has become a popular means of well logging because it can visually represent the lithologic and structural characteristics of strata.The manual interpretation of imaging logging is affected by the limi...Imaging logging has become a popular means of well logging because it can visually represent the lithologic and structural characteristics of strata.The manual interpretation of imaging logging is affected by the limitations of the naked eye and experiential factors.As a result,manual interpretation accuracy is low.Therefore,it is highly useful to develop effective automatic imaging logging interpretation by machine learning.Resistivity imaging logging is the most widely used technology for imaging logging.In this paper,we propose an automatic extraction procedure for the geological features in resistivity imaging logging images.This procedure is based on machine learning and achieves good results in practical applications.Acknowledging that the existence of valueless data significantly affects the recognition effect,we propose three strategies for the identification of valueless data based on binary classification.We compare the effect of the three strategies both on an experimental dataset and in a production environment,and find that the merging method is the best performing of the three strategies.It effectively identifies the valueless data in the well logging images,thus significantly improving the automatic recognition effect of geological features in resistivity logging images.展开更多
When people want to move to a new job, it is often difficult since there is too much job information available. To select an appropriate job and then submit a resume is tedious. It is particularly difficult for univer...When people want to move to a new job, it is often difficult since there is too much job information available. To select an appropriate job and then submit a resume is tedious. It is particularly difficult for university students since they normally do not have any work experience and also are unfamiliar with the job market. To deal with the informa- tion overload for students during their transition into work, a job recommendation system can be very valuable. In this research, after fully investigating the pros and cons of current job recommendation systems for university students, we propose a student profiling based re-ranking framework. In this system, the students are recommended a list of potential jobs based on those who have graduated and obtained job offers over the past few years. Furthermore, recommended employers are also used as input for job recommendation result re-ranking. Our experimental study on real recruitment data over the past four years has shown this method＇s potential.展开更多
Endmember extraction is a key step in the hyperspectral image analysis process. The kernel new simplex growing algorithm （KNSGA）, recently developed as a nonlinear alternative to the simplex growing algorithm （SGA...Endmember extraction is a key step in the hyperspectral image analysis process. The kernel new simplex growing algorithm （KNSGA）, recently developed as a nonlinear alternative to the simplex growing algorithm （SGA）, has proven a promising endmember extraction technique. However, KNSGA still suffers from two issues limiting its application. First, its random initialization leads to inconsistency in final results; second, excessive computation is caused by the iterations of a simplex volume calculation. To solve the first issue, the spatial pixel purity index （SPPI） method is used in this study to extract the first endrnember, eliminating the initialization dependence. A novel approach tackles the second issue by initially using a modified Cholesky fac- torization to decompose the volume matrix into triangular matrices, in order to avoid directly computing the determinant tauto- logically in the simplex volume formula. Theoretical analysis and experiments on both simulated and real spectral data demonstrate that the proposed algorithm significantly reduces computational complexity, and runs faster than the original algorithm.展开更多
The Clapping and Broadcasting Synchronization （CBS） algorithm, which is specifically designed for large-scale sensor networks with low communication overhead and high synchronization accuracy, is introduced. The CBS...The Clapping and Broadcasting Synchronization （CBS） algorithm, which is specifically designed for large-scale sensor networks with low communication overhead and high synchronization accuracy, is introduced. The CBS protocol uses broadcasting rather than pairwise communication to accomplish synchronization. In the CBS scheme, the initial offset of local clocks can be successfully eliminated by the operation of clapping nodes, which leads to significant improvement in synchronization accuracy. The CBS protocol was implemented on the TelosB platform and its performance was evaluated in a variety of experiments. The results demonstrate that the CBS protocol outperforms the current state-of-the-art approach, the Flooding Time Synchronization Protocol （FTSP）, in both single-hop and multi-hop scenarios in terms of synchronous precision and energy consumption. In multi-hop scenarios, the CBS algorithm keeps about 50% of its synchronization errors within 1 ms. In comparison, the FTSP keeps less than 7% of its synchronization errors within this range. In both single-hop and multi-hop scenarios, the CBS protocol is over 3.2 times more energy-efficient than the FTSP.展开更多
文摘Most traffic control systems available in major cities in Cameroon are still out dated, make use of theories and models which are very slow to implement, waste resources and their efficiency is very low. Thus the number of road accidents encountered on our major highways and inter urban traffic networks has been increasing despite the various efforts made by government and certain NGO to synthesize road users on certain aspects of traffic control and safety road use. Taxis are not left out in the whole show and most of the blame always falls on them. The need to use available Information and Communication Technology ICT to improve on the control of traffic in inter urban cities and major highways is imperative. ITS optimizes the use of resources, reduce pollution, contribute to environmental protection and increases the national economy. . This paper starts by giving a brief situation of the transportation system in Cameroon, its drawbacks and proposes an optimized ITS based system.
基金National Natural Science Foundation of China(Nos.11847069,11847127)Science Foundation of North University of China(No.XJJ20180030)。
文摘For conventional optical polarization imaging of underwater target,the polarization degree of backscatter should be pre-measured by averaging the pixel intensities in the no target region of the polarization images,and the polarization property of the target is assumed to be completely depolarized.When the scattering background is unseen in the field of view or the target is polarized,conventional method is helpless in detecting the target.An improvement is to use lots of co-polarization and cross polarization detection components.We propose a polarization subtraction method to estimate depolarization property of the scattering noise and target signal.And experiment in a quartz cuvette container is performed to demonstrate the effectiveness of the proposed method.The results show that the proposed method can work without scattering background reference,and further recover the target along with smooth surface for polarization preserving response.This study promotes the development of optical polarization imaging systems in underwater environments.
基金Project supported by the National Natural Science Foundation of China (Nos. 62373025, 12332004,62003013, and 11932003)。
文摘This paper proposes a distributed control method based on the differential flatness(DF) property of robot swarms. The swarm DF mapping is established for underactuated differentially flat dynamics, according to the control objective. The DF mapping refers to the fact that the system state and input of each robot can be derived algebraically from the flat outputs of the leaders and the cooperative errors and their finite order derivatives. Based on the proposed swarm DF mapping, a distributed controller is designed. The distributed implementation of swarm DF mapping is achieved through observer design. The effectiveness of the proposed method is validated through a numerical simulation of quadrotor swarm synchronization.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 61073047)the Fundamental Research Funds for the Central Universities(Grant No.HEUCFT1007andHEUCF100607)the State Key Laboratory of High-End Server & Storage Technology(Grant No.2009HSSA08)
文摘Network storage provides high scalability, availability and flexibility for storage systems, and is widely applied to many fields. Particularly, I/O performance is of great significance. Its application is wide and expanding rapidly. I/O performance has already become the bottleneck of the whole performance of computer systems for a long time, and under the condition of the present computer technology, I/O performance optimization method looks especially important. In the paper, I/O performance model was analyzed based on the combination of quasi birth, death process and queuing model, and then solved the model. A number of important related performance indicators and the relationship between them were given. By the way of example, this method can show the I/O performance more accurately. Finally, we got some useful conclusions, which may be used to evaluate network storage performance, and are the basis of confirming I/O scheduling strategy.
基金the National Natural Science Foundation of China(60773218)the Natural Science Foundation of Liaoning Province (20072031)
文摘Aiming at the problem of merging heterogeneous semantic taxonomy emerged in Web information integration, a method of building Web classification ontology （WCO） has been proposed. A WCO that is logically consistent with the suggested upper merged ontology （SUMO） is defined, together with axioms needed to classify Web pages. WCO can be used as a foundation of merging heterogeneous semantic taxonomy, and could be used to support Web information integration and classification based Web information retrieval.
文摘According to the problem of energy consumption in wireless sensor network （WSN）,this paper puts forward a routing optimization algorithm with quality of multi-service, using the function of routing optimization with quality of multi-service and membership function of satisfaction, which integrates the energy consumption of communication and residual and the information of time delay into the membership function of satisfaction to solve the equilibrium factor, so that it can become the optimal routing that balances the network lifetime, transmission delay of data, and node energy consumption of nodes. Simulation experiment shows that adopting the algorithm can make lifecycle of nodes longer and network transmit more data packets at the same time. Experimental results verify the algorithm can effectively balance the network energy, reduce the energy consumption and prolong the network lifetime.
基金the National Key Research and Development Program of China(2018YFB1004903)the Key Discipline Cultivation Program of Zhejiang Province(18JYXK018).
文摘Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in this era of technology.Instruction-assisted 3D technology can display stereo graphics and promote students'understanding of the geometrical structure and characteristics of graphics.Spatial ability includes several aspects.Few software programs are available for training different aspects of spatial ability for senior high school students.This study aims to explore an effective method for training the spatial ability for senior high school students,and to promote the development of students'independent inquiry ability.Methods First,an inquiry design strategy to improve the spatial ability of students is proposed.Based on this strategy,unity3D was used to develop a 3D inquiry environment that can use leap motion to complete a gesture interaction.Finally,researchers carried out experience-based activities and issued user experience questionnaires to participants to verify the application effect of the spatial ability inquiry environment and used interviews to understand the user experience of participants exploring the leap motion device in a 3D inquiry environment.Results 32 learners participated in the experiment.learners have a high score for perceived usefulness and willingness to use.Compared with the perceived ease of use and perceived usefulness,the average score of the application effect is relatively low.In terms of willingness to use,most of the learners expressed their willingness to use a similar inquiry environment for spatial ability training in the future.Conclusions The spatial ability inquiry environment can help learners better understand different concepts.The users showed a strong willingness to continue using the device.The device also updates the teaching concept to a certain extent and emphasizes the dominant position of a student.
文摘Imaging logging has become a popular means of well logging because it can visually represent the lithologic and structural characteristics of strata.The manual interpretation of imaging logging is affected by the limitations of the naked eye and experiential factors.As a result,manual interpretation accuracy is low.Therefore,it is highly useful to develop effective automatic imaging logging interpretation by machine learning.Resistivity imaging logging is the most widely used technology for imaging logging.In this paper,we propose an automatic extraction procedure for the geological features in resistivity imaging logging images.This procedure is based on machine learning and achieves good results in practical applications.Acknowledging that the existence of valueless data significantly affects the recognition effect,we propose three strategies for the identification of valueless data based on binary classification.We compare the effect of the three strategies both on an experimental dataset and in a production environment,and find that the merging method is the best performing of the three strategies.It effectively identifies the valueless data in the well logging images,thus significantly improving the automatic recognition effect of geological features in resistivity logging images.
基金Acknowledgements This work was partially supported by the State Key Laboratory of Software Development Environment of China （SKLSDE- 2015ZX-17）, the National Natural Science Foundation of China （Grant No. 61472021）, and the Fundamental Research Funds for the Central Universities.
文摘When people want to move to a new job, it is often difficult since there is too much job information available. To select an appropriate job and then submit a resume is tedious. It is particularly difficult for university students since they normally do not have any work experience and also are unfamiliar with the job market. To deal with the informa- tion overload for students during their transition into work, a job recommendation system can be very valuable. In this research, after fully investigating the pros and cons of current job recommendation systems for university students, we propose a student profiling based re-ranking framework. In this system, the students are recommended a list of potential jobs based on those who have graduated and obtained job offers over the past few years. Furthermore, recommended employers are also used as input for job recommendation result re-ranking. Our experimental study on real recruitment data over the past four years has shown this method＇s potential.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(Nos.LY13F020044 and LZ14F030004)the National Natural Science Foundation of China(No.61571170)
文摘Endmember extraction is a key step in the hyperspectral image analysis process. The kernel new simplex growing algorithm （KNSGA）, recently developed as a nonlinear alternative to the simplex growing algorithm （SGA）, has proven a promising endmember extraction technique. However, KNSGA still suffers from two issues limiting its application. First, its random initialization leads to inconsistency in final results; second, excessive computation is caused by the iterations of a simplex volume calculation. To solve the first issue, the spatial pixel purity index （SPPI） method is used in this study to extract the first endrnember, eliminating the initialization dependence. A novel approach tackles the second issue by initially using a modified Cholesky fac- torization to decompose the volume matrix into triangular matrices, in order to avoid directly computing the determinant tauto- logically in the simplex volume formula. Theoretical analysis and experiments on both simulated and real spectral data demonstrate that the proposed algorithm significantly reduces computational complexity, and runs faster than the original algorithm.
基金Supported by the National Key Basic Research and Development Program (973) of China (No. 2010CB334707)the National Natural Science Foundation of China (Nos. 60803126 and 61003298)+1 种基金the Natural Science Foundation of Zhejiang Province (Nos. Z1080979 and Y1101336)the Program for Zhejiang Provincial Key Innovative Research Team on Sensor Networks
文摘The Clapping and Broadcasting Synchronization （CBS） algorithm, which is specifically designed for large-scale sensor networks with low communication overhead and high synchronization accuracy, is introduced. The CBS protocol uses broadcasting rather than pairwise communication to accomplish synchronization. In the CBS scheme, the initial offset of local clocks can be successfully eliminated by the operation of clapping nodes, which leads to significant improvement in synchronization accuracy. The CBS protocol was implemented on the TelosB platform and its performance was evaluated in a variety of experiments. The results demonstrate that the CBS protocol outperforms the current state-of-the-art approach, the Flooding Time Synchronization Protocol （FTSP）, in both single-hop and multi-hop scenarios in terms of synchronous precision and energy consumption. In multi-hop scenarios, the CBS algorithm keeps about 50% of its synchronization errors within 1 ms. In comparison, the FTSP keeps less than 7% of its synchronization errors within this range. In both single-hop and multi-hop scenarios, the CBS protocol is over 3.2 times more energy-efficient than the FTSP.
