High Performance Processing and Analysis of Geospatial Data Using CUDA on GPU

Geospatial Big Data analytics are changing the way that businesses operate in many industries. Although a good number of research works have reported in the literature on geospatial data analytics and real-time data processing of large spatial data streams, only a few have addressed the full geospatial big data analytics project lifecycle and geospatial data science project lifecycle. Big data analysis differs from traditional data analysis primarily due to the volume, velocity and variety characteristics of the data being processed. One of a motivation of introducing new framework is to address these big data analysis challenges. Geospatial data science projects differ from most traditional data analysis projects because they could be complex and in need of advanced technologies in comparison to the traditional data analysis projects. For this reason, it is essential to have a process to govern the project and ensure that the project participants are competent enough to carry on the process. To this end, this paper presents, new geospatial big data mining and machine learning framework for geospatial data acquisition, data fusion, data storing, managing, processing, analysing, visualising and modelling and evaluation. Having a good process for data analysis and clear guidelines for comprehensive analysis is always a plus point for any data science project. It also helps to predict required time and resources early in the process to get a clear idea of the business problem to be solved.

Geospatial data exists in a variety of formats, including rasters, vector data, and large-scale geospatial databases. There exists an ever-growing number of sensors that are collecting this data, resulting in the explosive growth and scale of high-resolution remote sensing geospatial data collections. A particularly challenging domain of geospatial data processing involves mining information from high resolution remote sensing imagery. The prevalence of high-resolution raster geospatial data collections represents a significant data challenge, as a single remote sensing image is composed of hundreds of millions of pixels. We have developed a robust application framework which exploits graphics processing unit (GPU) clusters to perform high-throughput geospatial data processing. We process geospatial raster data concurrently across tiles of large geospatial data rasters, utilizing GPU co-processors driven by CPU threads to extract refined geospatial information. The framework can produce output rasters or perform image information mining to write data into a geospatial database.

Many-core framework, represented by Graphic Processing Unit (GPU), has been becoming more popular in scientific computing and data analysis, and Compute Unified Device Architecture (CUDA) allows developers to carry out computation on GPUs more conveniently. Matrix operation is one of the most important application scenarios of GPU computation and CUDA, widely appearing in domains like graph applications and artificial intelligence. This paper focuses on accelerating matrix power operation (MPO) process, which appears in many engineering problems and may be time-consuming when the scale of matrixes is large, with GPUs and CUDA. In this paper, three techniques are used to speed up the MPO process: matrix parallel reduction, matrix parallel multiplication and CUDA dynamic parallelism. The experiments were carried out on NVIDIA RTX 2080 Super and Intel(R) Core(TM) i7-10750H. The code is compiled and executed in Visual Studio 2019 community, the GPU driver version is 461.40, the CUDA version is 11.1, and the NVCC version is 11.1.74. With all three techniques, the MPO process can get hundreds of times speedup compared with the sequential multiplication process executed by Eigen library, even though the code of algorithm is hardly optimized. Moreover, with the number of power increasing, the efficiency of algorithm can be even higher because of the relatively fixed time consumed in data transmission and GPU memory allocation.

Geospatial information has been indispensable for many application fields, including traffic planning, urban planning, and energy management. Geospatial data are mainly stored in relational databases that have been developed over several decades, and most geographic information applications are desktop applications. With the arrival of big data, geospatial information applications are also being modified into, e.g., mobile platforms and Geospatial Web Services, which require changeable data schemas, faster query response times, and more flexible scalability than traditional spatial relational databases currently have. To respond to these new requirements, NoSQL (Not only SQL) databases are now being adopted for geospatial data storage, management, and queries. This paper reviews state-of-the-art geospatial data processing in the 10 most popular NoSQL databases. We summarize the supported geometry objects, main geometry functions, spatial indexes, query languages, and data formats of these 10 NoSQL databases. Moreover, the pros and cons of these NoSQL databases are analyzed in terms of geospatial data processing. A literature review and analysis showed that current document databases may be more suitable for massive geospatial data processing than are other NoSQL databases due to their comprehensive support for geometry objects and data formats and their performance, geospatial functions, index methods, and academic development. However, depending on the application scenarios, graph databases, key-value, and wide column databases have their own advantages.

Turbo Similarity Searching (TSS) is a two phases searching procedure that has been proven by previous works as one of the best searching method on chemical databases. TSS however consumes lots of computation time due to the number of searches and fusion carried out in the second phase of its procedure. Hence, TSS would not be able to cater the increase in the chemical database size due to this limitation. With the emergence of the parallel technology, this research looks into accelerating TSS on the widely-used many-cores i.e. the Graphics Processing Unit (GPU) and multi-cores platform. This would not only solve the computational time issue but also the cost as GPUs can be obtained at a lower cost. Hence, the implementation of TSS will help the medicinal chemist to execute the virtual screening in an accurate and fast manner. This study investigates the best possible method to parallelize TSS via experimentation of three parallel designs; two designs were implemented on GPU platform using the Compute Unified Device Architecture (CUDA) API namely CUDA 1 and CUDA 2 whilst one design was implemented on multi-core platform using OpenMP API. The CUDA 1 design had shown tremendous speedup and low GPU-memory utilization as compared to CUDA 2 design. In general observation, the parallel CUDA 1 was 131 times faster than sequential and 51 times faster than parallel OpenMP. This leads to the conclusion that CUDA 1 design as the best parallel design for TSS.

Implementation of Image Enhancement Algorithms and Recursive Ray Tracing using CUDA

This work presents an implementation of neocognitron neural network, using a high performance computing architecture based on GPU (graphics processing unit). Neocognitron is an artificial neural network, proposed by Fukushima and collaborators, constituted of several hierarchical stages of neuron layers, organized in two-dimensional matrices called cellular planes. For the high performance computation of face recognition application using neocognitron it was used CUDA (compute unified device architecture) as API (application programming interface) between the CPU and the GPU, from GeForce 8800 GTX of NVIDIA company, with 128 ALU's. As face image databases it was used a face database created at UFSCar, and the CMU-PIE (Carnegie Mellon University pose, illumination and expression) database. The load balancing was achieved through the use of cellular connections as threads organized in blocks, following the CUDA philosophy of development. The results showed the feasibility of this type of device as a massively parallel data processing tool, and that smaller the granularity and the data dependency of the parallel processing, better is its performance.

The small slop approximation (SSA) is an accurate method to calculate the electromagnetic (EM) scattering properties of rough surfaces. However, its computational complexity restricts its application to smaller domains and there is always the need for speedup in very large cases using pure central processing units (CPUs) hardware. With the development of graphics processing units (GPUs), more processors are dedicated to perform independent calculations. In addition, NVIDIA introduced a parallel computing platform, compute unified device architecture (CUDA), which provides researchers an easy way to use processors on GPU. To calculate EM scattering properties on GPU, we reformulate the SSA method with CUDA to take advantage of GPU threads. Because each thread executes synchronously and deals with a corresponding point data of rough surface, the CUDA-based SSA method calculates faster than the pure-CPU equivalent. To overcome memory limitations, the data of large rough surface are stored on hard disk. Moreover, a subsidiary thread is used to deal with the process of data transmission between the memory and the hard disk and reduce transmitting time further. The factors, block size, data transfers, and register, are also discussed in the optimization of the CUDA application. Test cases running on a NVIDIA GTX 460 GPU indicate that two orders of magnitude speedup, including file input and output, is obtained with our new formulation.

Watershed analysis, as a fundamental component of digital terrain analysis, is based on the Digital Elevation Model (DEM), which is a grid (raster) model of the Earth surface and topography. Watershed analysis consists of computationally and data intensive computing algorithms that need to be implemented by leveraging parallel and high-performance computing methods and techniques. In this paper, the Multiple Flow Direction (MFD) algorithm for watershed analysis is implemented and evaluated on multi-core Central Processing Units (CPU) and many-core Graphics Processing Units (GPU), which provides significant improvements in performance and energy usage. The implementation is based on NVIDIA CUDA (Compute Unified Device Architecture) implementation for GPU, as well as on OpenACC (Open ACCelerators), a parallel programming model, and a standard for parallel computing. Both phases of the MFD algorithm (i) iterative DEM preprocessing and (ii) iterative MFD algorithm, are parallelized and run over multi-core CPU and GPU. The evaluation of the proposed solutions is performed with respect to the execution time, energy consumption, and programming effort for algorithm parallelization for different sizes of input data. An experimental evaluation has shown not only the advantage of using OpenACC programming over CUDA programming in implementing the watershed analysis on a GPU in terms of performance, energy consumption, and programming effort, but also significant benefits in implementing it on the multi-core CPU.

Many algorithms for image processing and pattern recognition have recently been implemented on GPU (graphic processing unit) for faster computational times. However, the implementation using GPU encounters two problems. First, the programmer should master the fundamentals of the graphics shading languages that require the prior knowledge on computer graphics. Second, in a job which needs much cooperation between CPU and GPU, which is usual in image processings and pattern recognitions contrary to the graphics area, CPU should generate raw feature data for GPU processing as much as possible to effectively utilize GPU performance. This paper proposes more quick and efficient implementation of neural networks on both GPU and multi-core CPU. We use CUDA (compute unified device architecture) that can be easily programmed due to its simple C language-like style instead of GPU to solve the first problem. Moreover, OpenMP (Open Multi-Processing) is used to concurrently process multiple data with single instruction on multi-core CPU, which results ineffectively utilizing the memories of GPU. In the experiments, we implemented neural networks-based text detection system using the proposed architecture, and the computational times showed about 15 times faster than implementation using CPU and about 4 times faster than implementation on only GPU without OpenMP.

Based on the principle of QR loop iterations, this paper implements a parallel algorithm based on the hardware of GPU (Graphic Process Unit) by using routines from CUDA (Computer Unified Device Architecture) to find the eigenvalues of general matrices. CPU and GPU computing card form a client-server computing framework. Here, CPU can be regarded as a client and GPU card is considered as a computing server. For the experiment environment, this paper chooses a GPU card with the model of NVIDIA GeForce GTX460 as a server side and a CPU with the model of Intel Core i5-760 quad-core as a client side. Win7 64-bit is selected as the operating system. The parallel implementation consists of two parts:PA H and PA QR. PA H is a procedure that transforms a matrix A into the Hessenberg matrix B. PA QR is the actual parallel algorithm of the QR iterations that is imposed on the Hessenberg matrix B for finding eigenvalues of the general matrix A. The speedup ratio of the proposed algorithm is jarless when the number of iterations becomes greater. The experimental results show that the parallel implementation with CUDA on GPU only makes use of less running time than traditional sequential algorithms. The speedup ratio of PA H is between 1.79 and 7.81. The speedup ratio of PA QR is between 3.24 and 118.9. Especially, when the order of general matrix equals 8192, the amount of iterations becomes 10000. The speedup ratio of the PA-H and the PA QR can run up to 7.81 and 118.9 respectively.

In today's era, there is a great importance to parallel programming to gain high performance in terms of time required for data computation. There are some constraints to achieve parallelism on CPU (Central Processing Unit). It is possible to achieve data parallelism by SIMD (Single Instruction Multiple Data) on General Purpose Graphics Processing Unit (GPGPU) integrated with Central Processing Unit (CPU). In Database processing, most of the research is going on. In this implementation, Linear Regression Algorithm is used to achieve parallelism in database processing on images using a programming model, Compute Unified Device Architecture (CUDA) which uses multithreading technique. Most of the time is required to perform various operations on huge content-based database e.g. to read big images, datasets, etc. Linear Regression is one of the algorithm to predict, forecast, mine huge amount of data. Linear Regression using CUDA can achieve high performance. Here, Linear Regression is implemented on Graphics Processing Unit (GPU) and on CPU to process image database for prediction of data by finding Covariance matrix, Eigen values and Eigen vectors. The strongest Eigen vector is the best fit line. The time spent for computation is compared in both the implementations.

Most Computational Fluid Dynamics (CFD) applications solve the Naiver-Stokes equations using various discretization methods like Finite Difference Method (FDM), Finite Element Method (FEM), Finite Volume Method (FVM), etc. The most compute-intensive process in CFD algorithms is the pressure Poisson solver. Solving the pressure Poisson equation requires the solution of a set of linear simultaneous equations. As the problem size/complexity increases, so does the effort and time invested in solving the equations. This study presents fast and robust iterative solvers and the acceleration of the same using the Graphics Processing Unit (GPU) architecture. Serial versions of the codes are implemented in the C language and the parallelization on GPU is achieved using Compute Unified Device Architecture (CUDA). For this study, a two-dimensional heat conduction problem is considered. FDM is used for discretization. Iterative solvers Conjugate Gradient and Multi Grid methods have been implemented in serial and parallel. The performance enhancement with single GPU and CPU system over a single CPU in terms of computing time is reported. It is seen that multigrid algorithms are superior in convergence and nearly 13 times speed-up has been obtained through GPU acceleration using CUDA, for a grid size of 2048 X 2048. The tests have been done on a cluster with Intel(R) Xeon(R) CPU E5-2670 CPU and NVIDIA K10 GPU.

Performance models for asynchronous data transfers on consumer Graphics Processing Units

Data parallel programming provides an accessible model for exploiting the power of parallel computing elements without resorting to the explicit use of low level programming techniques based on locks, threads and monitors. The emergence of Graphics Processing Units (GPUs) with hundreds or thousands of processing cores has made data parallel computing available to a wider class of programmers. GPUs can be used not only for accelerating the processing of computer graphics but also for general purpose data-parallel programming. Low level data-parallel programming languages based on the Compute Unified Device Architecture (CUDA) provide an approach for developing programs for GPUs but these languages require explicit creation and coordination of threads and careful data layout and movement. This has created a demand for higher level programming languages and libraries which raise the abstraction level of data-parallel programming and increase programmer productivity. The Accelerator system was developed by Microsoft for writing data parallel code in a high level manner which can execute on GPUs, multicore processors using SSE3 vector instructions and FPGA chips. This paper compares the performance and development effort of the high level Accelerator system against lower level systems which are more difficult to use but may yield better results. Specifically, we compare against the NVIDIA CUDA compiler and sequential C++ code considering both the level of abstraction in the implementation code and the execution models. We compare the performance of these systems using several case studies. For some classes of problems, Accelerator has a performance comparable to CUDA, but for others its performance is significantly reduced; however in all cases it provides a model which is easier to use and enables greater programmer productivity.