ISSN 
2012 Vol. 41, No. 5
2012, 41(5): 642-648.
doi: 10.3969/j.issn.1001-0548.2012.05.001
Abstract:
Regarding to the complex network composed of the vast amount of tags in social tagging systems in Internet with their co-occurrences, the weights as the statistical semantic similarity of tag-tag edges and two abstract operators for weights computation were introduced, and a model of tag semantic similarity measurement is established. Comparing with traditional "users-items-tags" tripartite graph based statistic measures or network topology focused nodes similarity measures, this model provides a well defined formal system, which explicitly addresses both the statistical influential factors and the topological influential factors in computation of tag semantic similarities. A cluster of concrete implementations of the abstract operators are devised, which have similar format with T norms and S norms in fuzzy logics. In this cluster, concrete operators of different types or addressing different scopes of network topological factors are configurated with particular parameters (e.g.,parameter h and order l). By incorporating the AUC index and precision index in link prediction of complex network, an experiment is conducted to analyze the effectiveness and feasibility of these concrete operators. The experimental results show that these concrete operators introduce the effects of "semantic complementation" as well as the effects of "semantic destruction" when they are applied, but lower ordered calculations (e.g., 2≤l≤5 in the model) with these operators are helpful for precise analysis of tag semantic similarities, therefore they are useful in devising high accurate tag-aware recommendation algorithms for social tagging systems.
Regarding to the complex network composed of the vast amount of tags in social tagging systems in Internet with their co-occurrences, the weights as the statistical semantic similarity of tag-tag edges and two abstract operators for weights computation were introduced, and a model of tag semantic similarity measurement is established. Comparing with traditional "users-items-tags" tripartite graph based statistic measures or network topology focused nodes similarity measures, this model provides a well defined formal system, which explicitly addresses both the statistical influential factors and the topological influential factors in computation of tag semantic similarities. A cluster of concrete implementations of the abstract operators are devised, which have similar format with T norms and S norms in fuzzy logics. In this cluster, concrete operators of different types or addressing different scopes of network topological factors are configurated with particular parameters (e.g.,parameter h and order l). By incorporating the AUC index and precision index in link prediction of complex network, an experiment is conducted to analyze the effectiveness and feasibility of these concrete operators. The experimental results show that these concrete operators introduce the effects of "semantic complementation" as well as the effects of "semantic destruction" when they are applied, but lower ordered calculations (e.g., 2≤l≤5 in the model) with these operators are helpful for precise analysis of tag semantic similarities, therefore they are useful in devising high accurate tag-aware recommendation algorithms for social tagging systems.
2012, 41(5): 649-657.
doi: 10.3969/j.issn.1001-0548.2012.05.002
Abstract:
By analyzing some factual data from short message service database, more features of short message networks (SMNs) are captured, including degree distribution as well as weight distribution demonstrating the behavior of power-law with droop-head and heavy-tail, average vertex weight with vertex degree without power-law behavior etc. And then, a weighted evolutionary model (WEM) is proposed for SMNs by taking the short message interactive times between users as weights. The proposed WEM adopts a weighted local priority mechanism for node growing and a weight updating scheme which is based on the familiarity and recent contact frequency between users. Simulation results show that WEM fits real SMNs pretty well.
By analyzing some factual data from short message service database, more features of short message networks (SMNs) are captured, including degree distribution as well as weight distribution demonstrating the behavior of power-law with droop-head and heavy-tail, average vertex weight with vertex degree without power-law behavior etc. And then, a weighted evolutionary model (WEM) is proposed for SMNs by taking the short message interactive times between users as weights. The proposed WEM adopts a weighted local priority mechanism for node growing and a weight updating scheme which is based on the familiarity and recent contact frequency between users. Simulation results show that WEM fits real SMNs pretty well.
2012, 41(5): 658-662.
doi: 10.3969/j.issn.1001-0548.2012.05.003
Abstract:
The paper proposes a detecting method of multiple moving targets in stepped-frequency radar based on time-dechirping, in order to solve such problems that conventional processing methods without velocity compensation will reduce the detection performance because of range profile distortion and that velocity compensation methods cannot detect multiple targets with different velocities. This method performs the time-frequency transform processing for echo of all sub-pulses, and then the target parameter estimates value is obtained by two-dimensionally searching the processing products. The paper also describes the principle of detection and formulates the mathematical expressions of velocity resolution and cross-term peak strictly. Simulations for multi-moving targets are employed to validate the method.
The paper proposes a detecting method of multiple moving targets in stepped-frequency radar based on time-dechirping, in order to solve such problems that conventional processing methods without velocity compensation will reduce the detection performance because of range profile distortion and that velocity compensation methods cannot detect multiple targets with different velocities. This method performs the time-frequency transform processing for echo of all sub-pulses, and then the target parameter estimates value is obtained by two-dimensionally searching the processing products. The paper also describes the principle of detection and formulates the mathematical expressions of velocity resolution and cross-term peak strictly. Simulations for multi-moving targets are employed to validate the method.
2012, 41(5): 663-667,677.
doi: 10.3969/j.issn.1001-0548.2012.05.004
Abstract:
To deal with the problem of radar emitter recognition caused by noise environment, this paper presents a new method for emitter recognition based on backward cloud model and attribute similarity. In this method, a radar emitter database including noise data according with the reality is first constructed, the cloud numerical characteristic is then calculated based on backward cloud model. After that, the method for determining recognition weight of coefficients and a new classification implement based on backward cloud model and attribute similarity are proposed. Simulation results show that the proposed method can deal with the randomness and vagueness caused by noise environment much better and can conduct emitter recognition effectively in the adverse noise environment.
To deal with the problem of radar emitter recognition caused by noise environment, this paper presents a new method for emitter recognition based on backward cloud model and attribute similarity. In this method, a radar emitter database including noise data according with the reality is first constructed, the cloud numerical characteristic is then calculated based on backward cloud model. After that, the method for determining recognition weight of coefficients and a new classification implement based on backward cloud model and attribute similarity are proposed. Simulation results show that the proposed method can deal with the randomness and vagueness caused by noise environment much better and can conduct emitter recognition effectively in the adverse noise environment.
2012, 41(5): 668-670.
doi: 10.3969/j.issn.1001-0548.2012.05.005
Abstract:
Link quality, transmission rate of wireless links and channel competition among them determine the transmission capacity of multi-rate and multi-hop wireless networks together. This paper first builds a transmission mode and channel competition mode of wireless links, according to IEEE 802.11 DCF basic mode, and then gives the channel competition degree definitions both of wireless link and node, and finally proposes a channel competition aware end-to-end delay routing metric (CCAD) for multi-rate and multi-hop wireless networks. CCAD calculates the delays of wireless link and route, based on the transmission mode of wireless links and the channel competition degree of wireless nodes. As a result, link quality, transmission rate and channel competition are captured and measured together. NS2 simulation results show CCAD outperforms other metrics that have appeared in the literature, such as ETX, ETT and MIC.
Link quality, transmission rate of wireless links and channel competition among them determine the transmission capacity of multi-rate and multi-hop wireless networks together. This paper first builds a transmission mode and channel competition mode of wireless links, according to IEEE 802.11 DCF basic mode, and then gives the channel competition degree definitions both of wireless link and node, and finally proposes a channel competition aware end-to-end delay routing metric (CCAD) for multi-rate and multi-hop wireless networks. CCAD calculates the delays of wireless link and route, based on the transmission mode of wireless links and the channel competition degree of wireless nodes. As a result, link quality, transmission rate and channel competition are captured and measured together. NS2 simulation results show CCAD outperforms other metrics that have appeared in the literature, such as ETX, ETT and MIC.
2012, 41(5): 671-677.
doi: 10.3969/j.issn.1001-0548.2012.05.006
Abstract:
Due to the high security level of elliptic curve cryptography, the constructions of pseudorandom sequences generated from elliptic curves have been paid more attention recently. But the study mainly is concentrated upon the application of elliptic curves over prime fields. This paper defines pseudorandom numbers in the interval [0,1) by using elliptic curves over extension fields and presents a construction of binary threshold sequences. A discrepancy bounds for the pseudorandom numbers is derived and used to study the pseudorandomness of the binary threshold sequences in terms of estimating upper bounds on the well-distribution measure and the correlation measure of order l, both introduced by Mauduit and Sarkozy. The proofs are based on bounds on exponential sums and earlier relations of Mauduit, Niederreiter and Sarkozy between discrepancy and both measures above. Moreover, a lower bound on the linear complexity profile of the binary threshold sequences is presented in terms of the correlation measure of order l.
Due to the high security level of elliptic curve cryptography, the constructions of pseudorandom sequences generated from elliptic curves have been paid more attention recently. But the study mainly is concentrated upon the application of elliptic curves over prime fields. This paper defines pseudorandom numbers in the interval [0,1) by using elliptic curves over extension fields and presents a construction of binary threshold sequences. A discrepancy bounds for the pseudorandom numbers is derived and used to study the pseudorandomness of the binary threshold sequences in terms of estimating upper bounds on the well-distribution measure and the correlation measure of order l, both introduced by Mauduit and Sarkozy. The proofs are based on bounds on exponential sums and earlier relations of Mauduit, Niederreiter and Sarkozy between discrepancy and both measures above. Moreover, a lower bound on the linear complexity profile of the binary threshold sequences is presented in terms of the correlation measure of order l.
2012, 41(5): 678-683.
doi: 10.3969/j.issn.1001-0548.2012.05.007
Abstract:
Home eNodeB (HeNB) is a small cellular base station, typically designed for use in a home or small business. Deployed in untrusted environments, HeNB must be authenticated when it accesses to operator's core network. 3GPP has presented a method that EAP-AKA runs within IKEv2 between HeNB and security gateway for mutual authentication of HeNB and core network. This paper proposes a fast re-authentication scheme based on 3GPP standard. The proposed procedures reduce significantly the authentication overhand and improve the authentication speed compared with the initial authentication, without compromising the provided security services. Moreover, the proposed method does not modify the infrastructure in 3GPP and can be applied easily to the HeNB system. A detailed analysis of security is made by using AVISPA. In addition, an analysis of energy cost is carried out that compares the energy consumption induced by re-authentication and initial authentication. Finally, an analysis of communication cost analysis is provided that estimates the cost improvement of proposed re-authenitication over the initial authentication procedure.
Home eNodeB (HeNB) is a small cellular base station, typically designed for use in a home or small business. Deployed in untrusted environments, HeNB must be authenticated when it accesses to operator's core network. 3GPP has presented a method that EAP-AKA runs within IKEv2 between HeNB and security gateway for mutual authentication of HeNB and core network. This paper proposes a fast re-authentication scheme based on 3GPP standard. The proposed procedures reduce significantly the authentication overhand and improve the authentication speed compared with the initial authentication, without compromising the provided security services. Moreover, the proposed method does not modify the infrastructure in 3GPP and can be applied easily to the HeNB system. A detailed analysis of security is made by using AVISPA. In addition, an analysis of energy cost is carried out that compares the energy consumption induced by re-authentication and initial authentication. Finally, an analysis of communication cost analysis is provided that estimates the cost improvement of proposed re-authenitication over the initial authentication procedure.
2012, 41(5): 684-687.
doi: 10.3969/j.issn.1001-0548.2012.05.008
Abstract:
The simple power analysis attacks (SPA) of chosen-message contrary pairs is proposed by Miyamoto,which is an attack method based on searching the collision of modular multiplication. But in the real environment searching the collision is difficult. For this problem, the K-means clustering algorithm is proposed which can identify the modular multiplication collision automatically. The insignificant effects of collision attack are validated in the ASIC environment which suggested by Miyamoto. After the improvement method, by using a couple of power consumption curves it can recover more than 88% of the secret keys. Finally, the countermeasure of this attack method is discussed.
The simple power analysis attacks (SPA) of chosen-message contrary pairs is proposed by Miyamoto,which is an attack method based on searching the collision of modular multiplication. But in the real environment searching the collision is difficult. For this problem, the K-means clustering algorithm is proposed which can identify the modular multiplication collision automatically. The insignificant effects of collision attack are validated in the ASIC environment which suggested by Miyamoto. After the improvement method, by using a couple of power consumption curves it can recover more than 88% of the secret keys. Finally, the countermeasure of this attack method is discussed.
2012, 41(5): 688-692.
doi: 10.3969/j.issn.1001-0548.2012.05.009
Abstract:
Interference alignment (IA) is one of the promising technologies to solve the co-channel interference in wireless communication systems. It can provide users with degree of freedom that is linear to the number of users in systems. Considering that the objective function is too complicated to obtain the optimal precoding matrix in interference alignment, this paper, according to projection heory of subspace, proves an equivalent condition that the maximum desired signal can be achieved. And a Mini-norm of inner product algorithm is proposed to select the precoding matrix. Its performance is examined in a multi-user interference system by zero-forcing (ZF) and minimum-mean-square-error (MMSE) receiver respectively. Simulation results demonstrate the sum rate of proposed scheme is higher than existing schemes.
Interference alignment (IA) is one of the promising technologies to solve the co-channel interference in wireless communication systems. It can provide users with degree of freedom that is linear to the number of users in systems. Considering that the objective function is too complicated to obtain the optimal precoding matrix in interference alignment, this paper, according to projection heory of subspace, proves an equivalent condition that the maximum desired signal can be achieved. And a Mini-norm of inner product algorithm is proposed to select the precoding matrix. Its performance is examined in a multi-user interference system by zero-forcing (ZF) and minimum-mean-square-error (MMSE) receiver respectively. Simulation results demonstrate the sum rate of proposed scheme is higher than existing schemes.
2012, 41(5): 693-696.
doi: 10.3969/j.issn.1001-0548.2012.05.010
Abstract:
Duffing system is sensitive to specific signal and immune against the noise. This characteristic can be used to detect weak signal. For the fork problem of Duffing oscillator, intermittent chaos action represented by Duffing system in weak direct sequence spread spectrum (DSSS) signal detection is deduced through analyzing the Duffing system and Feigenbaum action. A new method based on intermittent chaotic action is proposed for weak DSSS signal detection. Finally, simulation experiment shows the validity of this method.
Duffing system is sensitive to specific signal and immune against the noise. This characteristic can be used to detect weak signal. For the fork problem of Duffing oscillator, intermittent chaos action represented by Duffing system in weak direct sequence spread spectrum (DSSS) signal detection is deduced through analyzing the Duffing system and Feigenbaum action. A new method based on intermittent chaotic action is proposed for weak DSSS signal detection. Finally, simulation experiment shows the validity of this method.
2012, 41(5): 697-701,786.
doi: 10.3969/j.issn.1001-0548.2012.05.011
Abstract:
Cooperative spectrum sensing is regarded as a key technology to tackle the challenges such as hidden terminal problem in local spectrum sensing of cognitive radio networks. In this paper, the cooperation strategy based on data fusion is chosen for better collective sensing performance, in which all cooperative users send their own local results of energy detection to the fusion centre for linear data combination and final decision. As the main focus of this work, the optimization of linear data fusion is investigated. Specifically, the optimal weight vectors for all users are derived under Neyman-Pearson (N-P) and Bayesian criteria, respectively. Monte Carlo simulations and numerical results are given under the assumption that the sensing channels follow Suzuki distribution. Obtained results demonstrate that the two optimal fusion schemes under N-P criterion, MDC and NDC have the similar detection performance, and they both outperform three other generally used schemes, including EGC, SC and MRC. Further, the optimal fusion scheme BAY, which is derived under Bayesian criterion, is verified to be more reliable than other schemes.
Cooperative spectrum sensing is regarded as a key technology to tackle the challenges such as hidden terminal problem in local spectrum sensing of cognitive radio networks. In this paper, the cooperation strategy based on data fusion is chosen for better collective sensing performance, in which all cooperative users send their own local results of energy detection to the fusion centre for linear data combination and final decision. As the main focus of this work, the optimization of linear data fusion is investigated. Specifically, the optimal weight vectors for all users are derived under Neyman-Pearson (N-P) and Bayesian criteria, respectively. Monte Carlo simulations and numerical results are given under the assumption that the sensing channels follow Suzuki distribution. Obtained results demonstrate that the two optimal fusion schemes under N-P criterion, MDC and NDC have the similar detection performance, and they both outperform three other generally used schemes, including EGC, SC and MRC. Further, the optimal fusion scheme BAY, which is derived under Bayesian criterion, is verified to be more reliable than other schemes.
2012, 41(5): 702-705.
doi: 10.3969/j.issn.1001-0548.2012.05.012
Abstract:
The distance between signal paths is limited in the power combining amplifiers using parallel multi-port microstrip lines as the output ports. There is no enough room for the unit amplifiers and their biasing elements. With the problem, a planar chain power divider/combiner is presented in this paper. A four-path planar divider/combiner is designed and fabricated. Its measured results are given: the return loss is less than -13 dB on the wide bandwidth of 2.0～4.5 GHz. The insertion loss is less than 0.8 dB. Additionally, a four-element power combining amplifier is also designed and fabricated. Its small signal gain on the bandwidth of 2.0～4.5 GHz is 13～19 dB, the saturated output power at 3.2 GHz is 26.4 dBm, and the power-combining efficiency is up to 85%.
The distance between signal paths is limited in the power combining amplifiers using parallel multi-port microstrip lines as the output ports. There is no enough room for the unit amplifiers and their biasing elements. With the problem, a planar chain power divider/combiner is presented in this paper. A four-path planar divider/combiner is designed and fabricated. Its measured results are given: the return loss is less than -13 dB on the wide bandwidth of 2.0～4.5 GHz. The insertion loss is less than 0.8 dB. Additionally, a four-element power combining amplifier is also designed and fabricated. Its small signal gain on the bandwidth of 2.0～4.5 GHz is 13～19 dB, the saturated output power at 3.2 GHz is 26.4 dBm, and the power-combining efficiency is up to 85%.
2012, 41(5): 706-711.
doi: 10.3969/j.issn.1001-0548.2012.05.013
Abstract:
In this paper, we propose an innovation denoising method named fractional integral denoising algorithm (FIDA) in order to remove noise as largely as possible. Our approach is based on the Riemann-Liouville definition of fractional calculus. The structures of FIDA on eight directions are discussed first. In the first aspect,the structures of fractional integral masks for FIDA on eight directions are constructed respectively. The eight directions used in our algorithm are 135 degrees, 90 degress, 45 degrees, 0 degrees, 180 degrees, 315 degrees, 270 degrees and 225 degrees. In addition, we also present the numerical implementation rules of FIDA for digital image. The experimental results show the effectiveness of our method according to the visual perception and peak signal noise ratio (PSNR) subjectively and objectively. Those results also demonstrate that FIDA can effectively remove noise while preserving the image's significant information simultaneously, especially for the edges and texture information with weak variation on gray intensity.
In this paper, we propose an innovation denoising method named fractional integral denoising algorithm (FIDA) in order to remove noise as largely as possible. Our approach is based on the Riemann-Liouville definition of fractional calculus. The structures of FIDA on eight directions are discussed first. In the first aspect,the structures of fractional integral masks for FIDA on eight directions are constructed respectively. The eight directions used in our algorithm are 135 degrees, 90 degress, 45 degrees, 0 degrees, 180 degrees, 315 degrees, 270 degrees and 225 degrees. In addition, we also present the numerical implementation rules of FIDA for digital image. The experimental results show the effectiveness of our method according to the visual perception and peak signal noise ratio (PSNR) subjectively and objectively. Those results also demonstrate that FIDA can effectively remove noise while preserving the image's significant information simultaneously, especially for the edges and texture information with weak variation on gray intensity.
2012, 41(5): 712-716.
doi: 10.3969/j.issn.1001-0548.2012.05.014
Abstract:
The gain of the driven-adjustable digitally controlled oscillator (DCO) varies largely in the output frequency range. To solve the problem, a circuit design method is presented to keep the DCO gain invariant in time-domain. To verify the proposed design method, a digitally controlled phase-locked loop (DCPLL) with the DCO is implemented by SMIC 0.18 μm logic 1P6M CMOS technology. The area of the DCO is 0.025 mm2. The measured results show that the frequency range of the DCO is from 76 MHz to 208 MHz. When the frequency of the DCO is 208 MHz, the measured peak-to-peak jitter and cycle jitter of the corresponding four-divided clock are 110 ps and 14.82 ps, respectively. The corresponding power of the DCO is 1.512 mW.
The gain of the driven-adjustable digitally controlled oscillator (DCO) varies largely in the output frequency range. To solve the problem, a circuit design method is presented to keep the DCO gain invariant in time-domain. To verify the proposed design method, a digitally controlled phase-locked loop (DCPLL) with the DCO is implemented by SMIC 0.18 μm logic 1P6M CMOS technology. The area of the DCO is 0.025 mm2. The measured results show that the frequency range of the DCO is from 76 MHz to 208 MHz. When the frequency of the DCO is 208 MHz, the measured peak-to-peak jitter and cycle jitter of the corresponding four-divided clock are 110 ps and 14.82 ps, respectively. The corresponding power of the DCO is 1.512 mW.
2012, 41(5): 717-722.
doi: 10.3969/j.issn.1001-0548.2012.05.015
Abstract:
To resolve the problem of future air traffic management under great traffic flow, high density, and small separation condition, a hybrid control system structure for flight confliction supervisory control is proposed.Firstly, a set of kinematic equations for the aircraft are proposed according to different flight stages. The confliction hyper-surfaces are defined based on air traffic control rules to forbidden the trajectory of the system composed by multiple aircrafts to cross it, and the crossing events can be recognized by a designed supervisor. In addition, the flight confliction discrete controller is designed according to resolutions available for air traffic controller to decide which control input should be applied. The continuous control input vector is derived under the condition that the difference value of confliction hyper-surfaces keeps negative in a resolution period, which keeps the air traffic system in the safe space. Case study proves that the method based on hybrid system theory can detect potential conflictions and resolve them in advance.
To resolve the problem of future air traffic management under great traffic flow, high density, and small separation condition, a hybrid control system structure for flight confliction supervisory control is proposed.Firstly, a set of kinematic equations for the aircraft are proposed according to different flight stages. The confliction hyper-surfaces are defined based on air traffic control rules to forbidden the trajectory of the system composed by multiple aircrafts to cross it, and the crossing events can be recognized by a designed supervisor. In addition, the flight confliction discrete controller is designed according to resolutions available for air traffic controller to decide which control input should be applied. The continuous control input vector is derived under the condition that the difference value of confliction hyper-surfaces keeps negative in a resolution period, which keeps the air traffic system in the safe space. Case study proves that the method based on hybrid system theory can detect potential conflictions and resolve them in advance.
2012, 41(5): 723-728.
doi: 10.3969/j.issn.1001-0548.2012.05.016
Abstract:
n this paper, a hybrid control based on adaptive inverse dynamics and position-error-based (PEB)architecture is proposed to overcome the dynamic parametric uncertainties and guarantee the transparency in teleoperation systems. First, the models of the human operator and the environment are incorporated into the dynamics of the master and the slave, respectively. Then, adaptive controllers based on inverse dynamics are designed and incorporated into PEB architecture. The performance of the system is studied by Lyapunov function.Simulation studies show that the proposed hybrid control method has good performances of position and force tracking.
n this paper, a hybrid control based on adaptive inverse dynamics and position-error-based (PEB)architecture is proposed to overcome the dynamic parametric uncertainties and guarantee the transparency in teleoperation systems. First, the models of the human operator and the environment are incorporated into the dynamics of the master and the slave, respectively. Then, adaptive controllers based on inverse dynamics are designed and incorporated into PEB architecture. The performance of the system is studied by Lyapunov function.Simulation studies show that the proposed hybrid control method has good performances of position and force tracking.
2012, 41(5): 729-734.
doi: 10.3969/j.issn.1001-0548.2012.05.017
Abstract:
Aimed at output voltage control of contactless power transfer (CPT) system, a novel capacitor array regulating strategy is presented. A special resonant capacitor array structure is designed for the strategy at the secondary side of the CPT system. The computing method of the array equivalent capacitance is also given.Furthermore, the relation between the array capacitance and the output voltage is analyzed and the output voltage regulating method is presented based on the switching among the array capacitors. The output control is realized by a piecewise control algorithm according to the output error amplitude. The control strategy can directly realize output control and satisfy the requirements for multi pickup and wide range control instead of using any auxiliary regulating stage. Finally, experiment results verify the capacitor array structure and the output control strategy.
Aimed at output voltage control of contactless power transfer (CPT) system, a novel capacitor array regulating strategy is presented. A special resonant capacitor array structure is designed for the strategy at the secondary side of the CPT system. The computing method of the array equivalent capacitance is also given.Furthermore, the relation between the array capacitance and the output voltage is analyzed and the output voltage regulating method is presented based on the switching among the array capacitors. The output control is realized by a piecewise control algorithm according to the output error amplitude. The control strategy can directly realize output control and satisfy the requirements for multi pickup and wide range control instead of using any auxiliary regulating stage. Finally, experiment results verify the capacitor array structure and the output control strategy.
2012, 41(5): 735-740.
doi: 10.3969/j.issn.1001-0548.2012.05.018
Abstract:
With the problem of QoS management for wireless multimedia sensor networks (WMSNs), a measurement-based QoS route mechanism is suggested. First the end-to-end QoS metrics are obtained through distributed measurement, second the hop-by-hop link QoS dynamics are estimated with NT(network tomography)model, and then feed back to the network layer route algorithm. An improved ant colony algorithm (ACA) is employed and the QoS metrics act as the heuristic factor. Simulation results show that this mechanism outperforms traditional algorithms in terms of QoS rating.
With the problem of QoS management for wireless multimedia sensor networks (WMSNs), a measurement-based QoS route mechanism is suggested. First the end-to-end QoS metrics are obtained through distributed measurement, second the hop-by-hop link QoS dynamics are estimated with NT(network tomography)model, and then feed back to the network layer route algorithm. An improved ant colony algorithm (ACA) is employed and the QoS metrics act as the heuristic factor. Simulation results show that this mechanism outperforms traditional algorithms in terms of QoS rating.
2012, 41(5): 741-747.
doi: 10.3969/j.issn.1001-0548.2012.05.019
Abstract:
Based on sensor nodesBased on sensor nodes' location information, the paper proposes a scheme on next-generation Based on sensor nodes' location information, the paper proposes a scheme on next-generation all-IP wireless sensor networks. The scheme creates the sensor node's IPv6 address structure based on location information and the automatic IPv6-address configuration algorithm. In the scheme, the location information is utilized to achieve the routing on the link layer and the reduced IPv6 stack is used to perform the routing. The paper analyzes the scheme's performance parameters, including consumed energy and routing delay time. The analytical results prove the validity and efficiency of the scheme.
Based on sensor nodesBased on sensor nodes' location information, the paper proposes a scheme on next-generation Based on sensor nodes' location information, the paper proposes a scheme on next-generation all-IP wireless sensor networks. The scheme creates the sensor node's IPv6 address structure based on location information and the automatic IPv6-address configuration algorithm. In the scheme, the location information is utilized to achieve the routing on the link layer and the reduced IPv6 stack is used to perform the routing. The paper analyzes the scheme's performance parameters, including consumed energy and routing delay time. The analytical results prove the validity and efficiency of the scheme.
2012, 41(5): 748-750.
doi: 10.3969/j.issn.1001-0548.2012.05.020
Abstract:
In order to ensure the video can be received by the legal client without attack of frame dropping,frame rearranging, and so on, a remote attestation protocol of video security based on Trusted Platform Module (TPM) is proposed. The architecture of the remote attestation protocol is explained in detail. Video content hash algorithm which is based on Fourier-Mellin is put forward to authenticate the video frame contents in order to prevent the man-in-the-middle from fabricating the response of remote attestation. To improve the efficiency of remote attestation, an attestation mode of differentiable granularity is developed. The experiments prove the effectiveness of the video hash algorithm and also demonstrate the characteristics of the proposed attestation mode of differentiable granularity.
In order to ensure the video can be received by the legal client without attack of frame dropping,frame rearranging, and so on, a remote attestation protocol of video security based on Trusted Platform Module (TPM) is proposed. The architecture of the remote attestation protocol is explained in detail. Video content hash algorithm which is based on Fourier-Mellin is put forward to authenticate the video frame contents in order to prevent the man-in-the-middle from fabricating the response of remote attestation. To improve the efficiency of remote attestation, an attestation mode of differentiable granularity is developed. The experiments prove the effectiveness of the video hash algorithm and also demonstrate the characteristics of the proposed attestation mode of differentiable granularity.
2012, 41(5): 751-758.
Abstract:
A new algorithm for reducing impulsive noise in color images is presented. Firstly, the synchronous pulse burst property of spiking cortical model (SCM) and the characteristic that impulse noise is significantly different from surrounding image pixels are introduced to locate noises in each channel of color images. Secondly, according to the number and position of detected noises, just the noises are filtered by the properly selected window and related filtering methods, and free-noise pixels are kept unchanged. Experimental data show that the proposed method can preserve more image details while sufficiently remove noises sufficiently. The good visual effect and objective results are achieved for color images corrupted at heavy level.
A new algorithm for reducing impulsive noise in color images is presented. Firstly, the synchronous pulse burst property of spiking cortical model (SCM) and the characteristic that impulse noise is significantly different from surrounding image pixels are introduced to locate noises in each channel of color images. Secondly, according to the number and position of detected noises, just the noises are filtered by the properly selected window and related filtering methods, and free-noise pixels are kept unchanged. Experimental data show that the proposed method can preserve more image details while sufficiently remove noises sufficiently. The good visual effect and objective results are achieved for color images corrupted at heavy level.
2012, 41(5): 759-763.
doi: 10.3969/j.issn.1001-0548.2012.05.022
Abstract:
In order to predict the uncertain trajectories in an efficient and accurate fashion, this paper introduces an uncertain trajectory prediction algorithm based on trajectory continuous time Bayesian networks (CTBN). It contains three essential phases: mining hotspot regions by partitioning trajectories into distinct hotspot clusters; constructing trajectory CTBN which is a states combination of three important variables including street identifier, moving speed, and moving direction; predicting the motion behavior of moving objects in order to obtain possible trajectories. Experimental results demonstrate that the proposed method can accurately predict the possible motion curves of moving objects in different trajectory data sets when compared with the naive prediction algorithm. In addition, experiments verify the essential role of hotspot region mining, which can help save prediction time at about 60% with a guarantee of high prediction accuracy.
In order to predict the uncertain trajectories in an efficient and accurate fashion, this paper introduces an uncertain trajectory prediction algorithm based on trajectory continuous time Bayesian networks (CTBN). It contains three essential phases: mining hotspot regions by partitioning trajectories into distinct hotspot clusters; constructing trajectory CTBN which is a states combination of three important variables including street identifier, moving speed, and moving direction; predicting the motion behavior of moving objects in order to obtain possible trajectories. Experimental results demonstrate that the proposed method can accurately predict the possible motion curves of moving objects in different trajectory data sets when compared with the naive prediction algorithm. In addition, experiments verify the essential role of hotspot region mining, which can help save prediction time at about 60% with a guarantee of high prediction accuracy.
2012, 41(5): 764-769.
doi: 10.3969/j.issn.1001-0548.2012.05.023
Abstract:
The logical abstract structure and concept of autonomous decentralized system (ADS) middleware are introduced. A physical structure of ADS middleware with high reliability and fault-tolerant capacity is presented and the related key technologies are discussed in detail. In order to construct data-driven application system design technology, the normalized handle programming model supporting several kinds of communication methods and information mapping mechanism are proposed. For the implementation of online expansion and online maintenance, generalized mixed-queue model are provided. The three-stage survival signal confirmation algorithm and reliable multicast communication algorithm based on the publish/subscribe model are put forward for the realization of online fault-tolerant capacity. Though the construction of 10 nodes ADS, the characteristics of ADS were verified.
The logical abstract structure and concept of autonomous decentralized system (ADS) middleware are introduced. A physical structure of ADS middleware with high reliability and fault-tolerant capacity is presented and the related key technologies are discussed in detail. In order to construct data-driven application system design technology, the normalized handle programming model supporting several kinds of communication methods and information mapping mechanism are proposed. For the implementation of online expansion and online maintenance, generalized mixed-queue model are provided. The three-stage survival signal confirmation algorithm and reliable multicast communication algorithm based on the publish/subscribe model are put forward for the realization of online fault-tolerant capacity. Though the construction of 10 nodes ADS, the characteristics of ADS were verified.
2012, 41(5): 770-774.
doi: 10.3969/j.issn.1001-0548.2012.05.024
Abstract:
The energy consumption of embedded software has become a key factor in embedded system design, and it is a fundamental work of analysis and optimization of energy consumption to measure the energy consumption of embedded software. This paper proposes a statistical model of embedded software energy consumption, including the energy consumptions of processor, memory and I/O controller, etc. Then, by analyzing the instruction cycle of ARM instruction set, a method for computing the instruction cycle number is designed so as to rapidly calculate the processor energy consumption of embedded software. This model has implemented in a high-precision instruction-level energy simulator HMSim. The experimental results show that the error rate of embedded software energy consumption estimated by this model is less than 10% compared with that measured by an electronic instrument. The achieved results also reflect how the embedded system energy consumption is influenced by different software designs.
The energy consumption of embedded software has become a key factor in embedded system design, and it is a fundamental work of analysis and optimization of energy consumption to measure the energy consumption of embedded software. This paper proposes a statistical model of embedded software energy consumption, including the energy consumptions of processor, memory and I/O controller, etc. Then, by analyzing the instruction cycle of ARM instruction set, a method for computing the instruction cycle number is designed so as to rapidly calculate the processor energy consumption of embedded software. This model has implemented in a high-precision instruction-level energy simulator HMSim. The experimental results show that the error rate of embedded software energy consumption estimated by this model is less than 10% compared with that measured by an electronic instrument. The achieved results also reflect how the embedded system energy consumption is influenced by different software designs.
2012, 41(5): 775-780.
doi: 10.3969/j.issn.1001-0548.2012.05.025
Abstract:
A solution of virtual service consolidation oriented to next generation green data center is introduced in this paper. Due to the peak-valley of the workload of services is in different time, a way to problem modeling is proposed based on workload timesharing analysis, which can achieve maximal resource utilization on the premise of keeping the required QoS. Meanwhile, the associated services and the mutual services, and the compatibility between services and servers are taken into account and five principles of consolidation are considered. By regarding the modeling as a multi-dimension bin packing problem with constraints, we propose a GGA-based heuristic to search for the global optimal solution. The experimental results show that the solution can get a better consolidation ratio than the former model.
A solution of virtual service consolidation oriented to next generation green data center is introduced in this paper. Due to the peak-valley of the workload of services is in different time, a way to problem modeling is proposed based on workload timesharing analysis, which can achieve maximal resource utilization on the premise of keeping the required QoS. Meanwhile, the associated services and the mutual services, and the compatibility between services and servers are taken into account and five principles of consolidation are considered. By regarding the modeling as a multi-dimension bin packing problem with constraints, we propose a GGA-based heuristic to search for the global optimal solution. The experimental results show that the solution can get a better consolidation ratio than the former model.
2012, 41(5): 781-786.
doi: 10.3969/j.issn.1001-0548.2012.05.026
Abstract:
The correlation between geographic distance and network delay plays an important role in network measurement. The analysis shows that the relation between distance and delay is linear. By comparing different network delay estimation methods, it is concluded that the statistical result of RTT of HTTP servers uniformly distributed in the earth should be calculated by using TCP handshake procedure. Measurement result under real condition reveals the linear relations between graphic distance and round trip delay in different areas show significant differences.
The correlation between geographic distance and network delay plays an important role in network measurement. The analysis shows that the relation between distance and delay is linear. By comparing different network delay estimation methods, it is concluded that the statistical result of RTT of HTTP servers uniformly distributed in the earth should be calculated by using TCP handshake procedure. Measurement result under real condition reveals the linear relations between graphic distance and round trip delay in different areas show significant differences.
2012, 41(5): 787-791.
doi: 10.3969/j.issn.1001-0548.2012.05.027
Abstract:
Traditional interaction security measurement method can not reflect the inherent security of software interaction basic attributes. In order to remedy this deficiency, this paper presents a method for the metrics of interaction inherent security. Through analyzing intrinsic security problems existed in the basic attributes of interaction, we puts forward the concepts of input-point complexity and input-point concentration ratio etc.,proposes a metric model of the inherent security of interaction of software based on input-point concentration ratio,and measures the inherent security of interaction of software through three examples. The measurement results show that it is effective by using input-point concentration ratio to measure inherent security of interaction. This method greatly reduces the disturbance of the changing of external factors on the metric results and, therefore,improves the credibility, integrity, and generality of the results.
Traditional interaction security measurement method can not reflect the inherent security of software interaction basic attributes. In order to remedy this deficiency, this paper presents a method for the metrics of interaction inherent security. Through analyzing intrinsic security problems existed in the basic attributes of interaction, we puts forward the concepts of input-point complexity and input-point concentration ratio etc.,proposes a metric model of the inherent security of interaction of software based on input-point concentration ratio,and measures the inherent security of interaction of software through three examples. The measurement results show that it is effective by using input-point concentration ratio to measure inherent security of interaction. This method greatly reduces the disturbance of the changing of external factors on the metric results and, therefore,improves the credibility, integrity, and generality of the results.
2012, 41(5): 792-795.
doi: 10.3969/j.issn.1001-0548.2012.05.028
Abstract:
Event-related potential (ERP) measurements are used to build functional network of spatial attention. The clustering coefficient is picked for analyzing this complex network. One new statistical parameter of existing edges percent between paired regions of interest (ROI) is proposed for analyzing ERP networks. Upon this,the properties of ERP functional network and the influences of locations of attention and stimulus are investigated.The fact that the clustering coefficient of ERP network is bigger than that of equivalent random network demonstrates the small world property of ERP network. Comparing existing edges percent between four ROI, the result shows that more edges exist between the stimulus contralateral posterior and anterior brain regions than those in ipsilateral regions. The statistical parameters of ERP networks between attention and unattention are obviously different, which indicates these parameters might be important indices of reflecting the ongoing brain dynamics. Proposal of new statistical parameters of complex networks may be a useful approach to study detailedly the connectivity of brain in various cognitive tasks.
Event-related potential (ERP) measurements are used to build functional network of spatial attention. The clustering coefficient is picked for analyzing this complex network. One new statistical parameter of existing edges percent between paired regions of interest (ROI) is proposed for analyzing ERP networks. Upon this,the properties of ERP functional network and the influences of locations of attention and stimulus are investigated.The fact that the clustering coefficient of ERP network is bigger than that of equivalent random network demonstrates the small world property of ERP network. Comparing existing edges percent between four ROI, the result shows that more edges exist between the stimulus contralateral posterior and anterior brain regions than those in ipsilateral regions. The statistical parameters of ERP networks between attention and unattention are obviously different, which indicates these parameters might be important indices of reflecting the ongoing brain dynamics. Proposal of new statistical parameters of complex networks may be a useful approach to study detailedly the connectivity of brain in various cognitive tasks.
2012, 41(5): 796-800.
doi: 10.3969/j.issn.1001-0548.2012.05.029
Abstract:
S-adenosyl-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In this paper, using bioinformatics strategy and validating by experiment, a novel SAMDC of Salvia miltiorrhiza Bge was cloned and identified which was being blasted by search of Salvia miltiorrhiza expressed sequencetags (EST) database with homologous gene cDNA of Nicotiana tabacum. This sequence was confirmed by RT- PCR, molecular cloning and sequencing. Sequence analysis showed that the Salvia miltiorrhiza SAMDC (SmSAMDC) consisted of three open reading frames (ORFs) (tiny ORF, small ORF and main ORF), and the main ORF encoded 360 amino acids with a calculated molecular weight of 39.4 kD and isoelectric point of 4.71. Tertiary structure predicted that 25.28%, 24.17% and 50.56% amino acids composed a helix,extending strand and random coil, respectively. Alignments of deduced amino acid sequences demonstrated that the SmSAMDC had several highly conserved motifs in plant SAMDC family, including a putative pro-enzyme cleavage site a PEST sequence.
S-adenosyl-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In this paper, using bioinformatics strategy and validating by experiment, a novel SAMDC of Salvia miltiorrhiza Bge was cloned and identified which was being blasted by search of Salvia miltiorrhiza expressed sequencetags (EST) database with homologous gene cDNA of Nicotiana tabacum. This sequence was confirmed by RT- PCR, molecular cloning and sequencing. Sequence analysis showed that the Salvia miltiorrhiza SAMDC (SmSAMDC) consisted of three open reading frames (ORFs) (tiny ORF, small ORF and main ORF), and the main ORF encoded 360 amino acids with a calculated molecular weight of 39.4 kD and isoelectric point of 4.71. Tertiary structure predicted that 25.28%, 24.17% and 50.56% amino acids composed a helix,extending strand and random coil, respectively. Alignments of deduced amino acid sequences demonstrated that the SmSAMDC had several highly conserved motifs in plant SAMDC family, including a putative pro-enzyme cleavage site a PEST sequence.
