Characteristic size extraction method and device for impact crater of numerical simulation plate-shaped structure

Abstract

The invention relates to the technical field of numerical simulation result analysis, in particular to a feature size extraction method and device for a numerical simulation plate-shaped structure impact crater. Comprising the following steps: identifying particle set fragments of a target plate after collision, and determining a maximum fragment particle set with the maximum number of particles; performing optimization alignment on the maximum fragment particle set and the particles corresponding to the target plate before impact to determine the overall displacement and rigid rotation of the particle set of the target plate before impact, and performing superposition of the particle sets of the target plate before impact and the target plate after impact; based on the superposed particle sets of the post-impact target plate and the pre-impact target plate, identifying a particle set of an impact pit formation area; projection analysis and particle volume summation are carried out on a particle set in an impact pit forming area, the depth, diameter and volume of an impact pit are rapidly extracted, the problems of high subjectivity, large error, long consumed time and the like caused by traditional manual brute force interpretation are solved, and the analysis efficiency and reliability of a high-speed / ultra-high-speed impact large-scale parallel simulation result are greatly improved.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of numerical simulation result analysis, in particular to a feature size extraction method and device for a numerical simulation plate structure impact crater. BACKGROUND

[0002] The formation of craters, perforations and other damages by projectile impact on metal / non-metal target plates is a typical phenomenon in high-speed / ultra-high-speed collision dynamics. Ground tests and numerical simulations are the main means of collision dynamics research. Ground tests are a method of obtaining data by measurement in a real or nearly real physical environment. Ground tests can truly reflect physical laws and the results are intuitive and credible. However, ground tests require a large amount of resources and human resources, and the cost is high. Designing test schemes, preparing samples, and repeating tests take a long time, are difficult to iterate quickly, and high-risk tests such as high-speed / ultra-high-speed collisions may damage equipment or endanger personnel safety. Numerical simulation is a method of simulating physical processes through computer models. It can reproduce extreme scenarios such as high-speed / ultra-high-speed collisions, does not require physical manufacturing, is flexible in parameter modification, can quickly compare and optimize multiple schemes, and can obtain full-field data and intuitively display process details. The meshless method such as Smoothed Particle Hydrodynamics (SPH) has become the mainstream and efficient choice for high-speed / ultra-high-speed collision dynamics simulation due to its significant advantages in handling high strain rate material deformation, fragmentation, and complex physical processes.

[0003] With the rapid improvement of computing power, by carrying out large-scale numerical simulation, the influence of changes in parameters such as projectile size, material, impact angle, and impact speed on target plate cratering, perforation, and other damages in high-speed / ultra-high-speed collision dynamics research can be quickly obtained. This also requires the identification of the impact damage characteristics of a large number of target plates to establish a regular understanding. The current method of extracting the size of target plate craters and perforations is mainly through manual interpretation of numerical simulation results, which has the problems of strong subjectivity, large error, and time-consuming.

[0004] Therefore, a new feature size extraction method and device for a numerical simulation plate structure impact crater are needed. SUMMARY

[0005] In order to solve the problem of strong subjectivity, large error, and time-consuming in the current manual interpretation method for extracting the size of target plate craters and perforations, the present application provides a feature size extraction method and device for a numerical simulation plate structure impact crater.

[0006] In one aspect, the present application provides a feature size extraction method for a numerical simulation plate structure impact crater, the method comprising: identify a set of particles of the target plate after the impact, determine a largest fragment particle set with the most number of particles; align the largest fragment particle set with the particles corresponding to the target plate before the impact to determine the overall displacement and rigid rotation of the set of particles of the target plate before the impact, and perform a registration of the set of particles of the target plate before the impact and the target plate after the impact; identify a set of particles of the impact crater region based on the registered set of particles of the target plate after the impact and the target plate before the impact; perform a projection analysis on the set of particles of the impact crater region to extract the depth, diameter, and volume of the impact crater.

[0007] In another aspect, there is provided a device for numerically simulating the extraction of characteristic dimensions of an impact crater of a plate-like structure, the device comprising: a determining unit configured to identify a set of particles of the target plate after the impact, and determine a largest fragment particle set with the most number of particles; an aligning unit configured to align the largest fragment particle set with the particles corresponding to the target plate before the impact to determine the overall displacement and rigid rotation of the set of particles of the target plate before the impact, and perform a registration of the set of particles of the target plate before the impact and the target plate after the impact; an identifying unit configured to identify a set of particles of the impact crater region based on the registered set of particles of the target plate after the impact and the target plate before the impact; an extracting unit configured to perform a projection analysis on the set of particles of the impact crater region to extract the depth, diameter, and volume of the impact crater.

[0008] In another aspect, there is provided a computing device comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the method of any of the embodiments of the present specification when executing the computer program.

[0009] In another aspect, there is provided a computer-readable storage medium having stored therein a computer program, the computer program, when executed in a computer, causing the computer to execute the method of any of the embodiments of the present specification.

[0010] In another aspect, there is provided a computer program product comprising a computer program, the computer program, when executed by a processor, implementing the steps of the method as described above.

[0011] This invention provides a method for extracting the characteristic dimensions of impact craters in a plate-like structure through numerical simulation. By identifying the largest set of fragment particles in the target plate after impact, the method optimizes the alignment of the largest set of fragment particles with the corresponding particles in the target plate before impact to determine the overall displacement and rigid rotation of the particle set in the target plate before impact. This achieves the overlap of the particle sets in the target plate before and after impact. Furthermore, the method identifies the particle set in the impact crater region and performs projection analysis and particle volume summation to quickly obtain the depth, diameter, and volume of the impact crater. This method overcomes the problems of strong subjectivity, large errors, and long time consumption caused by traditional manual brute-force interpretation, and greatly improves the efficiency and reliability of the analysis of large-scale parallel simulation results of high-speed / ultra-high-speed impacts. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart of a method for extracting the feature dimensions of a plate-shaped impact crater in numerical simulation, provided by an embodiment of the present invention. Figure 2 This is a diagram showing the cratering result of a target plate impact according to an embodiment of the present invention; Figure 3 This is a final effect diagram of particle set alignment provided by an embodiment of the present invention; Figure 4 This is a schematic diagram of missing particle identification provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of a particle set in an impact crater region provided by an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the size definition of a particle set in a given projection direction according to an embodiment of the present invention; Figure 7 This is a hardware architecture diagram of an electronic device provided in an embodiment of the present invention; Figure 8 This is a structural diagram of a feature size extraction device for a numerical simulation plate-shaped impact crater provided in an embodiment of the present invention. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0015] The specific implementation method is described below.

[0016] Please refer to Figure 1 This invention provides a method for extracting the feature dimensions of impact craters in a plate-like structure from numerical simulations. The method includes: Step 100: Identify the particle set fragments of the target plate after impact and determine the largest fragment particle set with the most particles. Step 102: Optimize the alignment of the largest fragment particle set with the particles corresponding to the target plate before impact to determine the overall displacement and rigid rotation of the particle set of the target plate before impact, and make the particle sets of the target plate before impact and the target plate after impact coincide. Step 104: Based on the particle sets of the target plate after the collision and the target plate before the collision, identify the particle set in the crater region. Step 106: Perform projection analysis and particle volume summation on the particle set in the impact crater region to extract the depth, diameter and volume of the impact crater.

[0017] In this embodiment of the invention, by identifying the largest fragment particle set of the target plate after impact, the largest fragment particle set is optimized and aligned with the corresponding particles of the target plate before impact to determine the overall displacement and rigid rotation of the particle set of the target plate before impact, thereby achieving the overlap of the particle sets of the target plate before and after impact. Furthermore, the particle set of the impact crater region is identified and projection analysis and particle volume summation are performed to quickly obtain the depth, diameter, and volume of the impact crater. This overcomes the problems of strong subjectivity, large errors, and long time consumption caused by traditional manual brute force interpretation, and greatly improves the efficiency and reliability of the analysis of large-scale parallel simulation results of high-speed / ultra-high-speed impacts.

[0018] The following description Figure 1 The execution method of each step is shown.

[0019] For step 100: In some implementations, step 100, "identifying the particle cluster fragments of the target plate after impact," includes: Select any particle from the total particle list and recursively search for all particles connected to that particle to obtain a particle set fragment; when the distance between particles is less than twice the smooth spacing, the particles have connectivity, and the connectivity has transitivity. Remove all particles identified as particle set fragments from the total particle list, then proceed to select any particle from the total particle list until all particle set fragments are identified.

[0020] In this embodiment of the invention, the specific implementation method is illustrated by the process of extracting the crater features formed by the impact of a target plate composed of two-dimensional particle sets with a length of 40mm and a width of 10mm. Figure 2 This represents a typical cratering result from a target impact. The light-colored particle set x0 represents the target before impact, and the dark-colored particle set x1 represents the target after impact. Note that the target undergoes overall displacement under the impact. When the impact point is at the edge of the target, the target may also rotate as a whole.

[0021] In this embodiment, the smooth length of each particle in the target particle set x0 is denoted as h. If the distance between two particles is less than 2h, then there is an interaction force between the two particles. At this time, the two particles are connected, and the connection has transitivity, that is, two particles that are simultaneously connected to a certain particle are also interconnected.

[0022] First, select any particle and recursively find all particles connected to it, which belong to the first fragment. Then, remove the identified particles from the total particle list and repeat the first step to obtain the second fragment. Repeat the above process until all fragments are identified. Divide a target particle set after impact into several fragments, with each fragment being disconnected from the others. Finally, sort the fragments by the number of particles in each fragment. Define the largest fragment particle set x1_b that contains the most particles extracted from the target particle set x1 after impact, and let x0_b represent the part of x1_b that corresponds to the particles in the target particle set x0 before impact.

[0023] Regarding step 102: In this step, step 102 may include: Determine the corresponding particle in the target plate before impact of the largest fragment particle set, perform rigid rotation and overall displacement on the corresponding particle set in the target plate before impact, and perform alignment optimization with the largest fragment particle set to obtain the final rigid rotation and overall displacement. Based on the final rigid rotation and overall displacement, the particle sets of the target plate before and after the impact coincide.

[0024] In some implementations, the final rigid rotation and overall displacement are calculated as follows: Rigid rotation θ = θx, θy, θz, where θx, θy, θz represent the rotation angles of the particle set along the X, Y, and Z axes, respectively. The rotation matrix is ​​expressed by the following formula: The alignment optimization objective between the corresponding particles of the largest fragment particle set in the target plate before impact and the largest fragment particle set is: In the formula, These are the corresponding particles of the largest fragment particle set in the target plate before impact. Let represent the largest fragment particle set, where i represents the particle number in the set, i=1,2,3,…, and d is the overall displacement. It is a rigid rotation. These are the rotation matrices of the particle set along the X, Y, and Z axes, respectively.

[0025] In this step, through particle coordinate alignment optimization, using the two parameters of the overall displacement d of the particle set and the rigid rotation θ, the particle set x0 of the target plate before impact can be transformed into x00 = R_x R_y R_z x0 + d. Then, it is compared with the target plate x1 after impact, and the alignment is continuously optimized until the particle set x00 after the target plate has moved and rotated before impact coincides with the target plate x1 before impact. The final effect of particle set alignment is as follows. Figure 3 As shown.

[0026] Regarding step 104: In this embodiment, step 104 includes: For each target particle in the target plate before the collision after the overlap, a particle with a nearest neighbor distance of no more than twice the average particle spacing is searched in the target plate after the collision after the overlap. If a neighboring particle exists, it means that a real particle exists at the target particle's location after the collision. If there are no neighboring particles, it means that the target particle's position was missing after the collision. Based on the locations where all particles are missing, the particle set in the impact crater region is determined.

[0027] In this embodiment, combined with Figure 4 For each particle in the particle set x00 that collided with the target plate after overlapping, find its nearest neighbor x1 particle whose distance is no more than twice the average particle spacing. If there is a nearest neighbor particle (particle j in the figure), then that position represents a real particle. If there is no nearest neighbor particle (particle i in the figure), then that position represents a missing particle.

[0028] For each particle in the particle set x00 of the target plate before and after the collision, after searching for particles in the target plate x1 after the collision whose neighbor distance does not exceed twice the average particle spacing, the particles in the particle set x00 of the target plate before the collision are divided into real particles and missing particles, such as... Figure 5 As shown, the missing particles are light-colored particles.

[0029] Regarding step 106: In some implementations, step 106 may include: The particle collection in the impact crater region is projected onto the direction of the plate normal, and the projection distance is determined as the depth of the impact crater. Calculate the volume of all particles in the particle concentration in the impact crater region and sum them to obtain the volume of the impact crater. In the direction perpendicular to the plate normal, take several uniformly distributed directions and project the particle set of the impact crater region into several directions respectively. Calculate the average value of the projection distance in all projection directions to obtain the diameter of the impact crater.

[0030] In this embodiment, the particle set consisting of missing particles is projected onto the plate normal direction (parallel to the y-axis), and the projection distance is the pit depth; the volume of all missing particles is the pit volume; in the direction perpendicular to the plate normal, several uniformly distributed directions (parallel to the x-axis) are selected, and the missing particle set is projected onto these directions. The average of the projection distances along all projection directions is the pit diameter. A schematic diagram of the distance of the missing particle set along a certain projection direction is shown below. Figure 6 As shown.

[0031] After completing the particle set information analysis of the impact crater region, the system automatically reads each numerical simulation result file sequentially and quickly generates information such as the particle set dimensions X, Y, and Z in the three orthogonal directions of the target plate, as well as the depth, diameter, and volume of each impact crater. Simultaneously, it can calculate the mass percentages (a, b, c) of the three largest fragments of the target plate after impact; and the dimensions (α1, β1, and γ1) of the largest fragment in the three orthogonal directions of the impacted target plate, for subsequent statistical analysis.

[0032] For targets with multiple damage points, a fast search program is run on all pore particles, and steps 10-106 are repeated to analyze and obtain the characteristic dimensions of multiple craters on the target plate. Impact perforation of the target plate can be considered an extreme case of impact cratering, which can also be quickly identified using this algorithm.

[0033] The technical effects brought about by this invention are reflected in the following aspects: 1) This algorithm is applicable to the analysis of characteristic dimensions such as crater formation and perforation (perforation is considered a special case of impact crater formation) of target plates by single or multiple projectiles at high speed / hyperspeed. It can simultaneously extract information such as the dimensions of the target plate in three orthogonal directions before impact and the fragmentation of the impact, and automatically generate data tables for subsequent result analysis.

[0034] 2) This algorithm quickly identifies the particle set information of the impact-damaged crater region by comparing the initial unimpacted target particle set with the impacted target particle set information. It obtains information such as the impact crater size, and its principle is simple. Verification results show that the time to extract the crater feature size and other information for a single three-projectile impact on a target plate (filled with 5 million SPH particles) is approximately 30 seconds, which is fast and efficient. This algorithm is particularly suitable for batch simulation result processing, overcoming the time-consuming problems of brute-force methods and greatly improving analysis efficiency.

[0035] 3) This algorithm obtains parameters such as the characteristic size of the impact crater by comparing and identifying particle information in the damaged area. The calculation error of parameters such as the diameter and depth of the impact crater does not exceed 1-2 particle sizes, and the calculation accuracy is relatively high. In addition, it unifies the processing benchmark and extraction method of batch simulation results, and eliminates the subjectivity and error caused by manually picking the coordinates of particles around the impact crater.

[0036] Figure 7 , Figure 8 As shown, this embodiment of the invention provides a device for extracting the feature dimensions of impact craters in a plate-like structure through numerical simulation. The device can be implemented in software, hardware, or a combination of both. From a hardware perspective, such as... Figure 7 The diagram shown is a hardware architecture diagram of a computing device for extracting the feature dimensions of a numerical simulation plate-shaped impact crater according to an embodiment of the present invention. (Except for...) Figure 7 In addition to the processor, memory, network interface, and non-volatile memory shown, the computing device in the embodiment may also include other hardware. Taking software implementation as an example, such as... Figure 8 As shown, a device in a logical sense is formed by the CPU of the computing device in which it is located reading the corresponding computer program from the non-volatile memory into the memory for execution.

[0037] like Figure 8 As shown, this embodiment provides a feature size extraction device for numerical simulation of plate-shaped impact craters, used to implement the method as described in any embodiment of the specification, including: The determination unit 801 is used to identify the particle set fragments of the target plate after impact and to determine the largest fragment particle set with the most particles. Alignment unit 802 is used to optimize the alignment of the largest fragment particle set with the particles corresponding to the target plate before impact, so as to determine the overall displacement and rigid rotation of the particle set of the target plate before impact, and to achieve the overlap of the particle sets of the target plate before impact and the target plate after impact. The identification unit 803 is used to identify the particle set in the impact crater region based on the particle set of the overlapping post-impact target plate and the pre-impact target plate. Extraction unit 804 is used to perform projection analysis on the particle set in the impact crater region to extract the depth, diameter and volume of the impact crater.

[0038] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a feature size extraction device for a numerical simulation plate-shaped impact crater. In other embodiments of the present invention, a feature size extraction device for a numerical simulation plate-shaped impact crater may include more or fewer components than illustrated, or combine some components, or split some components, or arrange different components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0039] The information interaction and execution process between the various units in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0040] This application also provides a computing device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a method for extracting the feature size of a plate-shaped impact crater according to any embodiment of the present invention.

[0041] Embodiments of this application also provide a computer-readable storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement the numerical simulation method for extracting the feature size of impact craters of plate-like structures provided in the above-described method embodiments.

[0042] Embodiments of this application also provide a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium and executes the computer program, causing the computer device to perform the feature size extraction method for numerical simulation plate-shaped impact craters described in any of the above embodiments.

[0043] For ease of description, the above systems or devices are described separately as various modules or units based on their functions. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware components.

[0044] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0045] Finally, it should be noted that in this document, relational terms such as first, second, third, and fourth are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0046] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for extracting the feature dimensions of impact craters in a plate-like structure using numerical simulation, characterized in that, include: Identify the particle set fragments of the target plate after impact and determine the largest fragment particle set with the most particles. The maximum fragment particle set is optimized and aligned with the particles corresponding to the target plate before impact to determine the overall displacement and rigid rotation of the particle set of the target plate before impact, and to achieve the overlap of the particle sets of the target plate before and after impact. Based on the particle sets of the target plate after the collision and the target plate before the collision, the particle set of the impact crater region is identified. Projective analysis was performed on the particle set in the impact crater region to extract the depth, diameter, and volume of the impact crater.

2. The method according to claim 1, characterized in that, The identification of particle fragments from the target plate after impact includes: Select any particle from the total particle list, and recursively search for all particles connected to that particle to obtain a particle set fragment; when the distance between the particles is less than twice the smooth spacing, the particles have connectivity, and the connectivity has transitivity. Remove all particles identified as particle set fragments from the total particle list, then proceed to select any particle from the total particle list until all particle set fragments are identified.

3. The method according to claim 1, characterized in that, The maximum fragment particle set is optimized and aligned with the particles corresponding to the target plate before impact to determine the overall displacement and rigid rotation of the particle set of the target plate before impact, and the particle sets of the target plate before and after impact are overlapped, including: Determine the corresponding particle in the target plate before impact of the largest fragment particle set, perform rigid rotation and overall displacement on the corresponding particle set in the target plate before impact, and perform alignment optimization with the largest fragment particle set to obtain the final rigid rotation and overall displacement. Based on the final rigid rotation and overall displacement, the particle sets of the target plate before and after the impact coincide.

4. The method according to claim 3, characterized in that, The final rigid rotation and overall displacement are calculated as follows: Rigid rotation θ = θx, θy, θz, where θx, θy, θz represent the rotation angles of the particle set along the X, Y, and Z axes, respectively. The rotation matrix is ​​expressed by the following formula: The alignment optimization objective between the corresponding particles of the largest fragment particle set in the target plate before impact and the largest fragment particle set is: In the formula, The corresponding particles of the largest fragment particle set in the target plate before impact. Let d represent the largest fragment particle set, i represent the particle number in the particle set, i=1,2,3,…, and d represent the overall displacement. It is a rigid rotation. These are the rotation matrices of the particle set along the X, Y, and Z axes, respectively.

5. The method according to claim 1, characterized in that, The identification of particle sets in the impact crater region based on the particle sets of the overlapping post-impact target plate and the pre-impact target plate includes: For each target particle in the target plate before the collision after the overlap, a particle with a nearest neighbor distance of no more than twice the average particle spacing is searched in the target plate after the collision after the overlap. If a neighboring particle exists, it means that a real particle exists at the target particle's location after the collision. If there are no neighboring particles, it means that the target particle's position was missing after the collision. Based on the locations where all particles are missing, the particle set in the impact crater region is determined.

6. The method according to claim 1, characterized in that, The projection analysis of the particle set in the impact crater region to extract the depth, diameter, and volume of the impact crater includes: The particle collection in the impact crater region is projected onto the direction of the plate normal, and the projection distance is determined as the depth of the impact crater. Calculate the volume of all particles in the particle concentration in the impact crater region and sum them to obtain the volume of the impact crater. In a direction perpendicular to the plate normal, several uniformly distributed directions are selected, and the particle set of the impact crater region is projected into these directions respectively. The average value of the projection distance of all projection directions is calculated to obtain the diameter of the impact crater.

7. A device for extracting the feature dimensions of a plate-like impact crater through numerical simulation, implementing the method as described in any one of claims 1-6, characterized in that, include: The determination unit is used to identify the particle set fragments of the target plate after impact and to determine the largest fragment particle set with the most particles. The alignment unit is used to optimize the alignment of the largest fragment particle set with the particles corresponding to the target plate before impact, so as to determine the overall displacement and rigid rotation of the particle set of the target plate before impact, and to achieve the overlap of the particle sets of the target plate before impact and the target plate after impact. The identification unit is used to identify the particle set in the impact crater region based on the particle set of the overlapping post-impact target plate and the pre-impact target plate. The extraction unit is used to perform projection analysis on the particle set in the impact crater region to extract the depth, diameter, and volume of the impact crater.

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