CN111737639A - 1-norm and 2-norm mixed time-varying graph signal distributed restoration method - Google Patents
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Abstract
The invention discloses a distributed repair method of a 1-norm and 2-norm mixed time-varying graph signal, which aims at the problem of poor repair effect of the existing time-varying graph signal repair method on an edge, and the repair problem of the time-varying graph signal is normalized into an unconstrained optimization problem of 1-norm and 2-norm mixing, wherein the time smoothness of the time-varying graph signal is characterized by adopting a 2-norm, the space smoothness is characterized by adopting a 1-norm with sparse solution, and the optimization problem is solved in a distributed manner by utilizing an alternating direction multiplier method; simulation experiments show that the method has better repairing performance, and particularly has better repairing effect on the edge of the graph signal.
Description
Technical Field
The invention relates to a time-varying graph signal processing technology neighborhood, in particular to a 1-norm and 2-norm mixed time-varying graph signal distributed repairing method.
Background
The time-varying graph signals are widely used in practical applications, such as urban temperature data acquired by a temperature sensor every hour, sea surface pressure data acquired by a pressure sensor every year, and the like. However, as the sensor is affected by its own performance and environmental factors, some corruption of the collected data may occur. Therefore, it is necessary to restore the time-varying graph signal according to the spatiotemporal correlation between data and restore the original data as much as possible.
Typically, the time-varying graph signals involve large amounts of data, requiring distributed repairs with relatively low computational complexity. In the existing distributed repair method, the spatial and temporal smoothness of the time-varying graph signal are measured by 2-norm, and the spatial sparsity of the graph signal cannot be well represented, which is shown in poor effect of repairing the edge of the graph signal.
Disclosure of Invention
The invention aims to provide a distributed repair method of a 1-norm and 2-norm mixed time-varying graph signal, aiming at the problem that the existing repair method of the time-varying graph signal has poor repair effect on edges.
The technical scheme for realizing the purpose of the invention is as follows:
a1-norm and 2-norm mixed time-varying graph signal distributed restoration method comprises the following steps:
1) converting a repairing process of a time-varying graph signal sampled by a sensor into an unconstrained optimization problem of mixing 1-norm and 2-norm, and constructing a graph model G (V, E) corresponding to the time-varying graph signal by using a 6-nearest neighbor algorithm, wherein V is a vertex set and comprises N vertexes in total, corresponds to each sensor node, and E is an edge set; let D be the degree matrix, W be the adjacency matrix, I be the unit matrix, and the Laplace matrix be defined as
2) Setting the dynamic model of the time-varying image signal asWherein xtIs the graph signal at time t, xt+1Is the graph signal at time t +1, wtIs additive random noise at the time t, tau is a parameter to be estimated, and x is obtained according to the first 10 graph signalstT is 0, …,9, and the parameter τ is estimated to be 0.022;
3) graph signal x for time t in time sequencet=[x(1),x(2),…,x(N)]TThe restoration is carried out, and the prediction graph signal at the time t is set asWhereinThe graph signal at the t-1 th moment after the restoration;
4) according to a certain proportion, randomly destroying the zero-setting image signal to obtain the image signal after zero-settingWherein xMFor uncorrupted picture signals, xμFor corrupted picture signals, xMThe number of the elements contained in the Chinese character is recorded as | M |;
5) for the destroyed picture signal xμApplying noise to obtain an observed value b of the graph signal, wherein n is additive noise;
6) initialization of original variables for each vertex i ∈ VAuxiliary variable z(0)(i) 0, dual variable w(0)(i) When the iteration time m is 0, the iteration termination threshold value is set;
7) obtaining the original variable by solving the minimum quadratic problemOriginal variablesThe expression is as follows:
wherein, the symbol (·)-1Representative matrix inversion operation (·)TRepresenting the matrix transpose operation, for each vertex i ∈ V, the repair value of the next graph signal at the m-th iterationEqual to the original variableThe value of the ith element in (1), i.e
8) For each vertex i ∈ V, auxiliary variables at the mth iteration are calculatedWherein H1(i, j) is the ith row and jth column element value of the high-pass filter corresponding matrix, sigma is the neighborhood radius, B (i, sigma) is the set of vertex i and its sigma order neighborhood nodes, and the function Sβ/γ(. cndot.) is defined as:
9) for each vertex i ∈ V, update the dual variable w at the mth iteration(m+1)(i)=w(m)(i)+s(i)-z(m +1)(i);
10) For each vertex i ∈ V, judgeWhether the result is true or not; if yes, ending the iteration, and then carrying out the m-th iteration to obtain the repair value of the lower graph signalAs the t-th timing chart signalThe repair result of (2); otherwise, returning the iteration times m +1 to the step 7) to continue the iteration until the iteration times m +1 are reachedUntil it is established.
In step 1), the objective function of the unconstrained optimization problem is a weighted sum of data fidelity, a 1-norm airspace non-smooth penalty term and a 2-norm time domain non-smooth penalty term, and the expression is as follows:
in formula (1), α is a weighting factor,is an N × N matrix, I|M|Is a unit matrix of | M | × | M |,H1an N × N matrix corresponding to the high-pass filter;
let auxiliary variable z be H1x, then equation (1) becomes:
the augmented lagrange function corresponding to equation (2) is:
in the formula (3), w is a dual variable, γ is a penalty factor,
based on the augmented Lagrange function, an alternating direction multiplier method is used for iterative solution of a formula (2), and the following results are obtained:
in step 4), the ratios are 10%, 20% and 50% of the total signal plot of the destroyed plot signal, respectively.
The invention provides a distributed repair method of a 1-norm and 2-norm mixed time-varying graph signal, which is used for solving the repair problem of the time-varying graph signal into an unconstrained optimization problem of 1-norm and 2-norm mixing, wherein the time smoothness of the time-varying graph signal is described by adopting a 2-norm, the space smoothness is described by adopting a 1-norm with sparse solution, and the optimization problem is solved in a distributed manner by utilizing an alternating direction multiplier method; simulation experiments show that the method has better repairing performance, and particularly has better repairing effect on the edge of the graph signal.
Detailed Description
The invention will now be further illustrated with reference to the following examples, but is not intended to be limited thereto.
Example (b):
a1-norm and 2-norm mixed time-varying graph signal distributed restoration method comprises the following steps:
1) the time-varying graph signals selected were temperature data per hour for 218 cities in the united states recorded by day 1/8/2010 with dimensions 218 × 24, X ═ XtT is 0, …,23, which means that a repairing process of a time-varying graph signal sampled by a temperature sensor is converted into an unconstrained optimization problem of mixing 1-norm and 2-norm, and a graph model G corresponding to the time-varying graph signal is constructed by using a 6-neighbor algorithm, wherein V is a vertex set and comprises 128 vertices, corresponding to each sensor node, and E is an edge set; let D be the degree matrix, W be the adjacency matrix, I be the unit matrix, and the Laplace matrix be defined as
The unconstrained optimization problem is characterized in that an objective function is a weighted sum of data fidelity, a 1-norm spatial domain unsmooth penalty term and a 2-norm temporal unsmooth penalty term, and an expression is as follows:
in formula (1), α is a weighting factor,is an N × N matrix, I|M|Is a unit matrix of | M | × | M |,H1an N × N matrix corresponding to the high-pass filter;
let auxiliary variable z be H1x, then equation (1) becomes:
the augmented lagrange function corresponding to equation (2) is:
in the formula (3), w is a dual variable, γ is a penalty factor,
based on the augmented Lagrange function, an alternating direction multiplier method is used for iterative solution of a formula (2), and the following results are obtained:
2) setting the dynamic model of the time-varying image signal asWherein xtIs the graph signal at time t, xt+1Is the graph signal at time t +1, wtIs additive random noise at the time t, tau is a parameter to be estimated, and x is obtained according to the first 10 graph signalstT is 0, …,9, and the parameter τ is estimated to be 0.022;
3) graph signal x for time t in time sequencet=[x(1),x(2),…,x(N)]TRepairing to repair the graph signal at time tFor example, the prediction map signal at time t isWhereinThe graph signal at the t-1 th moment after the restoration;
4) randomly destroying or zeroing the graph signals to obtain graph signals according to the proportion of 10%, 20% and 50% of the total graphWherein xMFor uncorrupted picture signals, xμFor corrupted picture signals, xMThe number of the elements contained in the Chinese character is recorded as | M |;
5) for the destroyed picture signal xμApplying noise to obtain an observed value b of the graph signal, wherein n is additive noise;
6) initialization of original variables for each vertex i ∈ VAuxiliary variable z(0)(i) 0, dual variable w(0)(i) When the iteration time m is 0, the iteration termination threshold value is set;
7) by solving the least quadratic problem, equation (4) above, the original variables are obtainedOriginal variablesThe expression of (a) is:
wherein, the symbol (·)-1Representative matrix inversion operation (·)TRepresenting the matrix transpose operation, for each vertex i ∈ V, the repair value of the next graph signal at the m-th iterationEqual to the original variableThe value of the ith element in (1), i.e
8) For each vertex i ∈ V, calculate the m-th timeAuxiliary variables under iterationWherein H1(i, j) is the ith row and jth column element value of the high-pass filter corresponding matrix, sigma is the neighborhood radius, B (i, sigma) is the set of vertex i and its sigma order neighborhood nodes, and the function Sβ/γ(. cndot.) is defined as:
9) for each vertex i ∈ V, update the dual variable w at the mth iteration(m+1)(i)=w(m)(i)+s(i)-z(m +1)(i);
10) For each vertex i ∈ V, judgeWhether the result is true or not; if yes, ending the iteration, and then carrying out the m-th iteration to obtain the repair value of the lower graph signalAs the t-th timing chart signalThe repair result of (2); otherwise, returning the iteration times m +1 to the step 7) to continue the iteration until the iteration times m +1 are reachedUntil it is established.
In order to verify the effectiveness of the method, the method is subjected to a simulation experiment and compared with the existing method; the evaluation indexes of the repairing method are as follows:
wherein x is0And x are the actual and repaired values of the graph signal, respectively, and the performance comparison shown in table 1 below was obtained by testing, and the average values of 24 RMSE and MRE were taken in table 1.
TABLE 1 repair Performance of American City temperature data
Further verifying the effect of the method on map signal edge repair, constructing a Minnesota traffic map signal with smooth segments, wherein the values of the map signal are respectively 1 and-1, and the map signal comprises an edge. According to the method, graph signals are damaged according to the proportion of 10%, the graph signals are repaired by the method and the existing method, the penalty of spatial smoothness is respectively 1-norm and 2-norm, and after the graph signals are repaired by the method and the existing method, RMSE values are respectively calculated to be 0.044 and 0.0625.
From the simulation results, the method of the present invention has better repairing performance than the existing method, especially in the aspect of repairing the graph signal edge.
Claims (3)
1. A distributed repair method for a 1-norm and 2-norm mixed time-varying graph signal is characterized by comprising the following steps:
1) converting a repairing process of a time-varying graph signal sampled by a sensor into an unconstrained optimization problem of mixing 1-norm and 2-norm, and constructing a graph model G (V, E) corresponding to the time-varying graph signal by using a 6-nearest neighbor algorithm, wherein V is a vertex set and comprises N vertexes in total, corresponds to each sensor node, and E is an edge set; let D be the degree matrix, W be the adjacency matrix, I be the unit matrix, and the Laplace matrix be defined as
2) Setting the dynamic model of the time-varying image signal asWherein xtIs the graph signal at time t, xt+1Is the graph signal at time t +1, wtIs additive random noise at the time t, tau is a parameter to be estimated, and x is obtained according to the first 10 graph signalstT is 0, …,9, and the parameter τ is estimated to be 0.022;
3) graph signal x for time t in time sequencet=[x(1),x(2),…,x(N)]TRepairing, wherein the prediction graph signal at the time t isWhereinThe graph signal at the t-1 th moment after the restoration;
4) according to a certain proportion, randomly destroying the zero-setting image signal to obtain the image signal after zero-settingWherein xΜFor uncorrupted picture signals, xμFor corrupted picture signals, xΜThe number of the elements contained in the Chinese character is recorded as | M |;
5) for the destroyed picture signal xμApplying noise to obtain an observed value b of the graph signal, wherein n is additive noise;
6) initialization of original variables for each vertex i ∈ VAuxiliary variable z(0)(i) 0, dual variable w(0)(i) When the iteration time m is 0, the iteration termination threshold value is set;
7) obtaining the original variable by solving the minimum quadratic problemOriginal variablesThe expression of (a) is:
wherein, the symbol (·)-1Representative matrix inversion operation (·)TRepresenting the matrix transpose operation, for each vertex i ∈ V, the repair value of the next graph signal at the m-th iterationEqual to the original variableThe value of the ith element in (1), i.e
8) For each vertex i ∈ V, auxiliary variables at the mth iteration are calculatedWherein H1(i, j) is the ith row and jth column element value of the high-pass filter corresponding matrix, sigma is the neighborhood radius, B (i, sigma) is the set of vertex i and its sigma order neighborhood nodes, and the function Sβ/γ(. cndot.) is defined as:
9) for each vertex i ∈ V, update the dual variable w at the mth iteration(m+1)(i)=w(m)(i)+s(i)-z(m+1)(i);
10) For each vertex i ∈ V, judgeWhether the result is true or not; if yes, ending the iteration, and then carrying out the m-th iteration to obtain the repair value of the lower graph signalAs the t-th timing chart signalThe repair result of (2); otherwise, returning the iteration times m +1 to the step 7) to continue the iteration until the iteration times m +1 are reachedUntil it is established.
2. The distributed restoration method for 1-norm and 2-norm mixed time-varying graph signals according to claim 1, wherein in step 1), the objective function of the unconstrained optimization problem is a weighted sum of data fidelity, a 1-norm spatial non-smooth penalty term and a 2-norm temporal non-smooth penalty term, and the expression is as follows:
in formula (1), α is a weighting factor,is an N × N matrix, IΜIs a unit matrix of | M | × | M |,H1an N × N matrix corresponding to the high-pass filter;
let auxiliary variable z be H1x, then equation (1) becomes:
the augmented lagrange function corresponding to equation (2) is:
in the formula (3), w is a dual variable, γ is a penalty factor,
based on the augmented Lagrange function, an alternating direction multiplier method is used for iterative solution of a formula (2), and the following results are obtained:
3. the distributed repair method for the 1-norm and 2-norm mixed time-varying graph signals according to claim 1, wherein in the step 4), the proportion of the corrupted graph signals is 10%, 20% and 50% of the total graph signal.
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CN112865748A (en) * | 2021-01-13 | 2021-05-28 | 西南大学 | Method for constructing online distributed multitask graph filter based on recursive least squares |
CN113190790A (en) * | 2021-03-30 | 2021-07-30 | 桂林电子科技大学 | Time-varying graph signal reconstruction method based on multiple shift operators |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160173736A1 (en) * | 2014-12-11 | 2016-06-16 | Mitsubishi Electric Research Laboratories, Inc. | Method and System for Reconstructing Sampled Signals |
CN110780604A (en) * | 2019-09-30 | 2020-02-11 | 西安交通大学 | Space-time signal recovery method based on space-time smoothness and time correlation |
CN110807255A (en) * | 2019-10-30 | 2020-02-18 | 桂林电子科技大学 | Optimization design method of M-channel joint time vertex non-downsampling filter bank |
CN111242867A (en) * | 2020-01-14 | 2020-06-05 | 桂林电子科技大学 | Graph signal distributed online reconstruction method based on truncated Taylor series approximation |
-
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Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160173736A1 (en) * | 2014-12-11 | 2016-06-16 | Mitsubishi Electric Research Laboratories, Inc. | Method and System for Reconstructing Sampled Signals |
CN110780604A (en) * | 2019-09-30 | 2020-02-11 | 西安交通大学 | Space-time signal recovery method based on space-time smoothness and time correlation |
CN110807255A (en) * | 2019-10-30 | 2020-02-18 | 桂林电子科技大学 | Optimization design method of M-channel joint time vertex non-downsampling filter bank |
CN111242867A (en) * | 2020-01-14 | 2020-06-05 | 桂林电子科技大学 | Graph signal distributed online reconstruction method based on truncated Taylor series approximation |
Non-Patent Citations (1)
Title |
---|
杨杰;蒋俊正;: "利用联合图模型的传感器网络数据修复方法", 西安电子科技大学学报 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112865748A (en) * | 2021-01-13 | 2021-05-28 | 西南大学 | Method for constructing online distributed multitask graph filter based on recursive least squares |
CN112865748B (en) * | 2021-01-13 | 2022-05-10 | 西南大学 | Method for constructing online distributed multitask graph filter based on recursive least squares |
CN113190790A (en) * | 2021-03-30 | 2021-07-30 | 桂林电子科技大学 | Time-varying graph signal reconstruction method based on multiple shift operators |
CN113190790B (en) * | 2021-03-30 | 2023-05-30 | 桂林电子科技大学 | Time-varying graph signal reconstruction method based on multiple shift operators |
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Application publication date: 20201002 Assignee: Guangxi Liuzhou Dino Xincheng Technology Co.,Ltd. Assignor: GUILIN University OF ELECTRONIC TECHNOLOGY Contract record no.: X2023980045651 Denomination of invention: A Distributed Restoration Method for Time-Varying Graph Signals with 1-Norm and 2-Norm Mixing Granted publication date: 20230516 License type: Common License Record date: 20231105 |