最新刊期
卷 41 ， 期 4 ， 2013
- 摘要：Currently,temporal and spatial factors are not considered together in current history trajectory indices,and the performance of indexes is sensitive to query size.This paper realizes adaptive octree based Trajectory clustering index(ATTI),which uses octree index spatial and temporal factors together and implements the query workload adaptive mechanism by virtual octree forest.The results show that ATTI can reduce half of range query process delay.关键词：adaptation;spatial index range query;spatio-temporal;octree2|2|0更新时间：2025-07-16
- 摘要：For the poor scalability,effectiveness and efficiency of the up-to-date utility based scheduling solutions,in this paper,we proposed a marginal utility function based scheduling method.In accordance with the feature of the marginal utility functions,the networking applications were divided into two classes,e.g.elastic and inelastic class.And then we built a utility based network resource scheduling model with the utility functions obtained from the corresponding marginal utility functions.The simulation experiments show that compare to the latest similar method and the corresponding approach in Lingo9.0,our algorithm increased the total utility by average of 5 and 4 percent with only 0.2% and 0.003% in the elapsed time.关键词：utility;marginal utility;marginal utility function;resource scheduling2|4|7更新时间：2025-07-16
- 摘要：Sparse representation coefficient contains strong discriminant information and sparsity preserving projections extracts features by sparse representation coefficient.This paper obtains kernel sparse representation coefficient in the high dimensional space by kernel method and use kernel sparse representation coefficient to construct adjacency matrix,then propose kernel sparsity preserving projections.Kernel sparse representation coefficient contains stronger discriminant information than sparse representation coefficient;therefore,KSPP could extract more efficient features than SPP.KSPP achieves good results in biometrics experiments of several databases.关键词：sparse representation;adjacency matrix;sparsity preserving projections;kernel method2|2|12更新时间：2025-07-16
- 摘要：At present all kinds of security methods are used to solve security problems of WSNs (wireless sensor networks).Along with the development of Internet of Things,wireless sensors in sensing layer of Internet of Things will also be diversified.Therefore,according to the sensing layer's characteristics and its unique security problems of Internet of Things,we propose a trust evaluation mechanism based on energy monitoring to solve the security issues of sensing layer.Firstly,this paper establishes an energy monitoring mechanism of wireless sensors.Secondly,it uses the correlation coefficient method to calculate the data of energy monitoring and conclude the trust metric of sensors.Simulation results show that the trust evaluation method of wireless sensors proposed in this paper has higher accuracy.关键词：WSNs(wireless sensor networks);energy monitoring;trust evaluation;correlation coefficient2|2|3更新时间：2025-07-16
- 摘要：It is significant to reduce packet delivery delay for real-time applications in a wireless network.The algorithm of computing networking coding gain(NCG) and the method of simplifying coding graph are presented,which are used in the proposed coding gain aware routing(CGAR) protocol.The NCG and expected transmission count(ETX) of wireless links are used in CGAR to compute the time of transmitting a packet coming from a new flow,which is used as a routing metric in choosing a route so as to reduce packet delivery delay.Simulation results show that the proposed CGAR outperforms the DCAR and COPE protocols in terms of delay.关键词：wireless networks;network coding;delay;routing2|2|3更新时间：2025-07-16
- 摘要：A new coverage optimization problem named disjoint set k-cover for fusion-based coverage of WSN is investigated in this paper where sensor nodes are assumed using a fusion-based collective probabilistic sensor model.First,the problem is formulated as a fusion-based coverage game and then the game is proved as a potential game.So that the optimal solution is a pure Nash equilibrium.Second,we present the conditions that determine the independence of coverage utility among sensor nodes.Furthermore,two distributed algorithms only based on local information are proposed and proven to be convergent to pure Nash equlibria.Finally,experimental results show that Nash equilibria can provide a near-optimal and well-balanced solution to the problem.关键词：wireless sensor network;coverage optimization;fusion sensing;game theory;distributed computing2|2|5更新时间：2025-07-16
- 摘要：The fault probability of the elementary gate p for the reliability estimation of gate-level circuits had been given based on expert experience or as a constant generally.Considering the time change of properties of fault probability and the input-interconnects of different elementary gates,a fault probability model considering input loads and time factor is constructed.Theoretical analysis and experimental results show that the bimodal lognormal distribution based on weak link model is more suitable to describe the time distribution of the input-interconnect fault probability.The reliability values of ISCAS 85 benchmark circuits are calculated and compared by the iterative probability transfer matrix based on the proposed model,the reliability calculation method recommended by MIL-HDBK-217 standard and the reliability simulation method adopted by Monte Carlo.The industrial standard is also used to further test.It shows that the proposed model is reasonable.关键词：time factor;input load;input-interconnect;CMOS device;the fault probability of different elementary gates2|2|2更新时间：2025-07-16
- 摘要：In this paper,we puts forward a fuzzy transformation method for double-input-single-output fuzzy system,and points out that not only this fuzzy transformation has intimate connections with single-input-single-output fuzzy systems,but also the fuzzy system constructed with this fuzzy transformation has good universal approximation.By applying the fuzzy transformation to the fuzzy reasoning modeling method,we establish a new fuzzy reasoning modeling method and derive the differential equation model and the state-space model for the system which is studied.The theoretical analysis and simulate experiment show that the differential equations based on fuzzy transformation have good universal approximation.关键词：fuzzy control;fuzzy transformation;universal approximation;differential equations;state space model2|2|11更新时间：2025-07-16
- 摘要：A novel dynamic cache partitioning strategy based on pseudo-LRU policies(PLRU-SCP)is proposed in this paper.The analysis circuit for the proposed strategy makes use of a new statistical method based on binary tree,and the partitioning circuit employs the non-exhaustive algorithm.Besides,we presents a novel shared cache structure.According to simulation results,the proposed shared cache with PLRU-SCP outperforms those without the partitioning strategy using LRU policy(LRU-NP)by 11.05% on average performance,and has a better performance than those with the utility-based partitioning strategy using LRU method(LRU-UCP)by 8.66%.关键词：shared cache;pseudo-LRU policy;binary tree analysis;non-exhaustive partitioning algorithm2|2|2更新时间：2025-07-16
- 摘要：Asynchronous datapath of LDPC decoder is proposed in this paper.Glitches and redundant computations are decreased by asynchronous design.Clock tree is replaced by handshake control units.Taking advantages of input data statistical characteristic,key arithmetic elements in the datapath are proposed.Two types of datapaths including synchronous design and clock-gating design are also implemented as contrasts.Three designs exploit similar architecture and realize the same function by 0.18μm CMOS process.Simulation result shows that the proposed asynchronous design features the lowest power.Compared with the synchronous and clock-gating designs,it saves 42.0% and 32.6% power respectively.Its performance is a little bit worse than the synchronous design,but is better than the clock-gating design.The delay of the synchronous design is 1.09ns,the clock-gating design is 1.61ns,and the proposed design is 1.20ns.关键词：LDPC code;asynchronous design;low power;comparator;adder2|4|1更新时间：2025-07-16
- 摘要：Owing to the exponential nature of the memory or run-time complexity,many existing methods can only synthesize 3-qubit logic circuits using quantum logic gate library,however,a few can optimally synthesize 3-qubit logic circuits for quantum NOT,CNOT,Controlled-V and Controlled-V+(NCV)gates,the key approach reduces the NCV quantum circuit synthesis problem to four-valued logic synthesis.This paper proposes using NCV gates to create a new quantum logic gate library,which is exactly the same as NCV gate library in the synthesis of all optimal 3-qubit circuits,thus it also reduces the four-valued logic synthesis to easily solved two-valued logic synthesis.We present a 3-qubit efficient synthesis algorithms based on perfect hash function,which can quickly construct all optimal 3-qubit circuits--the average speed that synthesizes circuits with minimum cost is nearly 127 times faster than that of the best result of Maslov 2007.关键词：reversible logic;NCV gate library;multiple-valued logic;perfect hash function;quantum cost2|2|3更新时间：2025-07-16
- 摘要：Central Force Optimization (CFO) is a new deterministic multi-dimensional search metaheuristic algorithm based on the metaphor of gravitational kinematics.CFO is a deterministic algorithm that explores a decision space by "flying" a group of "probes" whose trajectories are governed by two simple equations derived from the gravitational metaphor.The paper makes a thorough research on the probes move governed by the equations of gravitational motion through the Celestial Mechanics,establishing the relationship between CFO algorithm and Celestial Mechanics and analyzing CFO convergence through mathematics analysis of Celestial Mechanics.Finally,Whatever initial probes distribute,all the probes converge the deterministic result.It provides a theoretical base for further researching.关键词：probe;central force optimization;deterministic algorithm;analyse of convergence2|2|4更新时间：2025-07-16
- 摘要：Inspired by some complex system concepts,a new evolutionary algorithm is designed in paper.In the new algorithm,crossover,selecting operator,mutating operator and evolutionary strategy are improved by some characteristic properties of complex system.These improvements represent the complexity of energy distribution,space searching and information use during the evolution.And the simple procedure structure of evolutionary algorithm is reserved.Then,the influences of two parameters are discussed in paper.Finally,all functions of CEC'2012 competition on large scale problems are tested by the new evolutionary algorithm.And testing results of the new evolutionary algorithm are compared with those of other excellent algorithms.The results show that comprehensive capabilities of the new evolutionary algorithm,presented in the paper,are better than all comparing algorithms.关键词：complex system;evolution algorithm;large scale;global optimization2|2|2更新时间：2025-07-16
- 摘要：In order to solve the problems that the image fusion method based on separable discrete wavelet transform has block effect in the fused image and the spatial resolution is lower in the fusion result image of nonsubsampled non-separable wavelet transform,a new multispectral image fusion method based on sampled two channel non-separable wavelets is proposed.The filter banks relating to this kind ofwavelet are constructed.The multi-resolution decompositions of the intensity of the multispectral image and panchromatic image are performed in sampled mode using the constructed filter bank.The low frequency and high frequency coefficients are fused by different fusion rules.The experiment results show that this method has good visual effect.The fusion performance outperforms the IHS fusion method,the fusion method based on DWT,IHS-DWT,IHS-Contourlet transform,IHS-Curvelet transform and SRF in preserving spectral quality and high spatial resolution information.When compared with the fusion method based on nonsubsampled two-channel non-separable wavelet,the proposed method has been observed to have higher spatial resolution and good global spectral information.关键词：image fusion;two-channel sampled non-separable wavelets;multispectral image;panchromatic image2|3|5更新时间：2025-07-16
- 摘要：Diffusion weighted magnetic resonance image (DWI) should be denoised effectively for the corresponding procedure due to its property of imaging and application.Different from the normal gray level image,the noise in DWI is distributed under the Rician distribution.The commonly used local denoising method is lack of the synthetic implementation of the statistical information of noise,especially the Rician noise in the DWI.This paper proposed a modified LMMSE restoration method used for DWI.The proposed method used the local information to estimate the parameter of the Rician noise and modified the LMMSE using the principle of the anisotropic filter.The simulation and experiment of the synthetic DWI and real human brain DWI dataset demonstrated that the proposed method can effectively remove the Rician noise compared to the commonly used local denoising method and improve the robustness and validity of the DTI.关键词：diffusion weighted magnetic resonance imaging;image restoration;linear minimum mean square error;Rician noise2|2|0更新时间：2025-07-16
- 摘要：Conventional self-phasing method is difficult to achieve excellent impedance matching and circularly polarized (CP) radiation simultaneously over a wide band in quadrifilar helix antenna (QHA) designs.This is because the lowest points of return loss and axial ratio cannot match.Although QHA with additional feeding network can solve the problem above,the size is too large to be used in handset applications.In this paper,we proposed a QHA attached a compact feeding network on its bottom end to achieve balanced power division and quadrature phasing in a wide bandwidth.QHA with the proposed feeding network could achieve broadband CP radiation.Moreover,the configuration is compact and very suitable for GPS/CNSS portable mobile handset applications.关键词：circularly polarized antenna;quadrifilar helix antenna;feeding network;broadband;mobile handset2|2|7更新时间：2025-07-16
- 摘要：In this paper,the termination(almost termination)of generalized quantum loop program(for short GQLoop)is firstly investigated,where the loop bodies of GQLoop are described by bit flip channel,depolarizing channel,amplitude damping channel and phase damping channel,respectively.Secondly,when the loop bodies are the embedding of two kinds of GQLoop,the conditions of the termination(almost termination)of GQLoop are addressed.It shows that the conditions of the termination(almost termination)of GQLoop depend on the parameters occuring in the quantum channels.Finally,when the loop bodies are an unitary operation on the principle system and the environment under the open quantum system,after implementing unitary operation,the computed processing of the quantum program is discussed by performing a partial trace over the environment.关键词：generalized quantum loop program;quantum operation;termination;almost termination;composite quantum system2|2|5更新时间：2025-07-16
- 摘要：The frequency ranges of intermittent sine signals are relatively wide when Duffing chaotic system detects those given signals by utilizing the state changes.According to this problem,a method is analyzed and proved in this paper,which is based on the relation of system's parameters and measured signals' amplitudes and frequencies by the method of Mélnikov,that Duffing system's damping parameters can be increased to improve the ability of detecting sine signals.In addition,simulation results of Duffing system's detecting intermittent sine signals are shown by adjusting damping parameters under noise and noise free condition separately.Simulation results show that the presented method is effective.关键词：Duffing system;damping;frequency range;signal detection2|2|5更新时间：2025-07-16
- 摘要：Based on NP(Neyman-Pearson)criterion,a reliability test to evaluate the blind processing results of LFM(Linear Frequency Modulation)signals is proposed in this paper.The reference signals are constructed depending on the certain modulation model in accordance to the identified result at first.By analysis of the parameters differences from the probability distribution characteristics of the modulus of the correlation series under the different hypotheses,the reliability test problem for blind processing results of LFM signals is performed by the proposed statistic and the threshold based on NP criterion.Simulation results show that the proposed method can be used to verify the reliability for blind processing results of LFM signals at low signal-to-noise ratio.关键词：blind signal processing;reliability test;NP(Neyman-Pearson)criterion;LFM(linear frequency modulation)2|3|6更新时间：2025-07-16
- 摘要：A novel polarization-space-time adaptive matched filter (PST-AMF) detector is proposed for slowly moving target detection in airborne polarimetric phased array radar in Gaussian clutter environments with unknown target polarization steering vector and clutter covariance matrix.The adaptive polarimetric detector has been developed by using the likelihood ratio test (LRT) principle,which incorporates firstly the estimation of the target polarisation into its detector.The quantitative expressions of probability of detection and false alarm are deduced.We also prove that it ensures constant false alarm (CFAR) property with respect to the covariance matrix of noise.More remarkably,it has the same performance,but a lower complexity,than the corresponding polarization-space-time generalized likelihood ratio test (PST-GLRT).The new PST-AMF detector performed significantly better than the traditional space-time adaptive matched filter (ST-AMF) detector,especially in the case of the target slowly moving.Finally,Simulations demonstrate the robustness of the detection algorithm.关键词：polarization array;space time adaptive processing;polarization-space-time adaptive processing;filtering;detection2|2|3更新时间：2025-07-16
- 摘要：In this paper,a network-traffic based topic extracting and analyzing method is introduced.The new topic definition for web2.0 and the classification of user behavior is given;the detecting method of user behavior,topic extracting method,and data storage algorithm is also proposed.At last,a prototype of topic collector based on network traffic is implemented;the testing results show that the user behavior and the hot topic can be collected and detected effectively and correctly,and the new method provides a new data channel for analyzing public opinion.关键词：public opinion;hot topic;emergent event;network traffic2|2|1更新时间：2025-07-16
- 摘要：As a typical method for solving non-smooth convex optimization problems,cutting plane method is widely used in solving support vector machine problems. However,this algorithm suffers from the instability problem. To ease this instability,researchers proposed an optimized cutting plane algorithm which incorporated a line search stage. However,the computational complexity of such algorithm is too high for applications where the number of training samples is large. In this paper we propose an active set based optimized cutting plane algorithm to reduce the computation complexity of the original algorithm. When computing the objective function and performing line search,only those samples which fall in the active set are considered. Compared to optimized cutting plane algorithm,the proposed algorithm needs to calculate the objective function and perform line search only for a small fraction of the samples,leading to a significant drop in computational complexity without losing accuracy.关键词：cutting plane algorithm;support vector machine;optimized cutting plane algorithm;active set2|2|0更新时间：2025-07-16
- 摘要：Support Vector Data Description(SVDD)is introduced into multiple instance learning.Three multi-instance learning methods based on SVDD are presented,which include Multiple Instance Learning based on SVDD and bag classification(mi-SVDD)or instance classification(MI-SVDD),and Multiple Instance Learning based on SVDD and positive instance prediction(SVDD-MILD-I).Experimental results on MUSK dataset show that precisions of mi-SVDD and MI-SVDD are quite comparable to those of mi-SVM and MI-SVM;SVDD-MILD-I can get highest accuracy among all the methods known so far.Experimental results in the application of content based image retrieval in COREL image collections demonstrate that precision achieved by SVDD-MILD_I is higher than the others.Additionally,SVDD-MILD_I discriminates the misclassification-prone images between Beach and Mountains quite well.关键词：machine leaning;pattern classification;multi-instance learning;support vector data description2|2|2更新时间：2025-07-16
- 摘要：Coordinate descent (CD) method is one of the most efficient algorithms in dealing with the large-scale optimization problems for its simple operation,cheap computational cost and practical efficiency.However until now,almost all the-state-of-art CD algorithms require the smoothness assumption of loss functions due to solving the subproblems in closed-form.In this paper,within the structural learning framework,we present a new stochastic CD(SCD)algorithm for non-smooth losses,in which the randomly selected single variable problem is solved using Comid method.Theoretical analysis indicates that the proposed algorithm has an O(√t/t) convergence rate for general convex problems and an O(lnt/t) convergence rate for strongly convex problems.The experiments demonstrate the expected efficiency of our SCD algorithms when coping with the L1-regularized Hinge loss problems.关键词：machine learning;optimization;large-scale;coordinate descent methods;non-smooth losses;structural learning;COMID2|2|4更新时间：2025-07-16
- 摘要：This paper proposed attribute-based signeryption(ABSC) scheme.By introducing the idea of signeryption,attribute-based eneryption(ABE) was improved to attribute-based signeryption,which can complete eneryption and signature with the cost of once encryption,or to complete the mutual authention and signature with the cost of once eneryption,or to complete the mutual authentication with the cost of once signature.Through constructing the access structure on vector space,ABSC breaks the threshold limit.And based on the discrete logarithm problem,the verification algorithm was designed so that the deceptions from the internal participants can be found.关键词：attributed-based;vector space;signcryption2|2|2更新时间：2025-07-16
- 摘要：In order to minimize the transmission errors for stereoscopic images,we propose an error concealment algorithm based on local reliable disparities.First,taking the block loss and the factors of color similarity and geometric distance proximity into account,we design a base-point-biased window to conduct the adaptive weight disparity matching.Second,local reliable disparities are calculated according to the disparity constancy and left-right consistency.Finally,the Winner-Takes-All (WTA) strategy is adopted to estimate the disparity of lost block which will be used to get the data of corresponding block for error concealment.Experimental results show that compared with other algorithms,the proposed method can produce better PSNR and subjective quality of reconstructed image while the computational complexity is almost the same.关键词：stereoscopic images;error concealment;base-point-biased;adaptive weigh;winner-takes-all2|2|1更新时间：2025-07-16
- 摘要：The traditional techniques of PET image reconstruction such as the least-squares and the penalty weighted least-squares can obtain high quality image,but they can't suppress the noise well under the limited angle situation.The total variation(TV) was used widely as penalty in image reconstruction,which applied the sparsity prior of image and could accurately reconstruct the image from the limited angle (a small quality of measurement).This article combined the advantages of the weighted least squares and total variation and constructed the objective function based on them,and solved the objective function using the alternate methods.The objective function was decomposed into two simple optimization problems for solving quadratic optimization and total variation regularization,the over relaxation method and the gradient descent method were used to solve these two optimization problems.Simulations using Zubal model were utilized to estimate the qualities of the reconstructed images,the evaluation parameters included CORR,VAR and SNR.The experimental results show the proposed algorithm has better performance in noise suppression and good reconstruction effect under limited angle situations.关键词：positron emission tomography;image reconstruction;weighted least squares;total variation2|3|4更新时间：2025-07-16
- 摘要：The dark channel prior algorithm is effective to some extent when working on some single outdoor scene hazing images.However,it has to expend large amounts of memory storage and computational time.Besides,the result of the sky region is not accurate enough.In this paper,we estimate the transmission map through processing the edges and non-edges respectively with different neighborhoods and obtain more accurate atmospheric light value by departing the sky part or the most hazed region of the image.This method can get a similar or even a better dehazing result than the classical haze removal methods,and moreover take less memory consumption and get much faster computational speed.关键词：image restoration;dark channel prior;dehazing;sky region2|2|24更新时间：2025-07-16
- 摘要：Secure multiparty computation is a key privacy-preserving technology in cyberspaces and a research focus in the international cryptographic community.We first present a new encoding scheme to encode private data.By using this encoding scheme together with homomorphic encryption scheme,we construct a new scheme for Yao's millionaires' problem and prove its privacy-preserving property.This new scheme is more concise,more general and can be applied to compare any two objects on which a total order can be defined.We finally utilize the new scheme to propose a solution to the coprime problem and prove the privacy-preserving properties of the solution.关键词：cryptography;homomorphic encryption;secure multiparty computation;millionaires' problem;coprime problem3|2|35更新时间：2025-07-16
- 摘要：This paper aims to present an approach for mining regular association rules and maximal association rules using soft set and inclusion degree theory from transactional datasets.We first give the notions of inclusion degree,association rule and maximum association rules between attribute sets of soft set.Then we discuss the relationship between inclusion degree and confidence.Furthermore,we give an algorithm of soft maximal association rules mining using inclusion degree of soft set.The experiments show the algorithm improves greatly the performance of maximal association rules mining.关键词：soft sets;inclusion degree;association rules;soft maximal association rules2|3|6更新时间：2025-07-16
- 摘要：It is an open issue how to generate base classifiers with higher diversity and accuracy for ensemble learning.In this paper,a novel algorithm is proposed to solve this problem---particle swarm optimization is used to search for an optimal feature weight distribution which makes the classification error rate of training data sample by the distribution in AdaBoost minimal.Then,the feature subspace is constructed according to the optimal feature weight distribution,which is applied into the training process of AdaBoost.Thus,the accuracy of base classifier is advanced;meanwhile,the diversity between classifiers is improved.Finally,majority voting method is utilized to fuse the base classifiers' results and experiments have been done to attest the validity of the proposed algorithm.关键词：ensemble learning;random subspace;Adaboost algorithm;particle swarm optimization2|2|11更新时间：2025-07-16
- 摘要：In this paper,the design and implementation of a broadband balanced power amplifier(PA)using a GaN HEMT transistor is presented.Two Lange couplers are used for a balanced PA configuration,and two multi-section matching networks are used in both input and output ports to improve the bandwidth of PA.The carrier sheet is made of AlSiC whose thermal expansion coefficient is close to silicon's,and the power amplifier operates in a pulse mode in order to reduce the heat dissipated on it.By biasing the amplifier at V_DS=28V,I_DS=110mA,the measurement results show 12～13dB linear gain and 56%～65% drain efficiency in the 1.5～3.5GHz frequency range.Moreover,an output power higher than 8W is maintained over the band.关键词：wideband power amplifier;GaN HEMT;balanced power amplifier6|3|7更新时间：2025-07-16
- 摘要：This paper discribes a 5GHz double sideband up-converted mixer design in a SoC-based sensor chip for physiological signal detection.Characterized by conventional Gilbert core,the proposed topology introduced current-bleeding and third-order distortion cancellation to relax nonlinearity.By biasing the transconductance stages into heterogeneous operation region the conversion loss was better than 5dB and the mixer obtained in-band(4.5GHz-5.5GHz) IIP3 ranged from 22.3dBm to 39.8dBm,and the noise figure is less than 8.2dB.Differential implementation and inductive source degeneration are adopted,by which the second and the third harmonics are further suppressed,given that the mixer merely consumes 8.4mW from 1.2V supply.关键词：radar sensor chip;up-converted mixer;distortions;linearization2|2|1更新时间：2025-07-16
- 摘要：To solve the pumping units motor energy consumption problem,a constraint relational mode of power factor,control angle and delay angle,and automatic control method are proposed.Controller of pumping unit is designed based on self-learning algorithm.The design adopts current voltage adjusting technology,samples the signal of phase angle between voltage and current,analyzes the signal with self-learning algorithm,adjusts the direction and the size of thyristor control angle to change working voltage of motor,so as to save energy efficiently.Testing results show that motor average effective power loss decreases by 14.95%,average none effective power loss decreases by 30.42%.关键词：algorithm;energy saving;controller;frequency control;motor2|3|1更新时间：2025-07-16
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