scholarly journals Algorithm and Architecture Optimization for 2D Discrete Fourier Transforms with Simultaneous Edge Artifact Removal

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Faisal Mahmood ◽  
Märt Toots ◽  
Lars-Göran Öfverstedt ◽  
Ulf Skoglund
Keyword(s):  
Energy Consumption ◽  
Biomedical Applications ◽  
High Performance ◽  
Fourier Transforms ◽  
External Memory ◽  
Image Size ◽  
Artifact Removal ◽  
Spectral Leakage ◽  
Discrete Fourier Transforms ◽  
Intermediate Storage

Two-dimensional discrete Fourier transform (DFT) is an extensively used and computationally intensive algorithm, with a plethora of applications. 2D images are, in general, nonperiodic but are assumed to be periodic while calculating their DFTs. This leads to cross-shaped artifacts in the frequency domain due to spectral leakage. These artifacts can have critical consequences if the DFTs are being used for further processing, specifically for biomedical applications. In this paper we present a novel FPGA-based solution to calculate 2D DFTs with simultaneous edge artifact removal for high-performance applications. Standard approaches for removing these artifacts, using apodization functions or mirroring, either involve removing critical frequencies or necessitate a surge in computation by significantly increasing the image size. We use a periodic plus smooth decomposition-based approach that was optimized to reduce DRAM access and to decrease 1D FFT invocations. 2D FFTs on FPGAs also suffer from the so-called “intermediate storage” or “memory wall” problem, which is due to limited on-chip memory, increasingly large image sizes, and strided column-wise external memory access. We propose a “tile-hopping” memory mapping scheme that significantly improves the bandwidth of the external memory for column-wise reads and can reduce the energy consumption up to 53%. We tested our proposed optimizations on a PXIe-based Xilinx Kintex 7 FPGA system communicating with a host PC, which gives us the advantage of further expanding the design for biomedical applications such as electron microscopy and tomography. We demonstrate that our proposed optimizations can lead to 2.8× reduced FPGA and DRAM energy consumption when calculating high-throughput 4096×4096 2D FFTs with simultaneous edge artifact removal. We also used our high-performance 2D FFT implementation to accelerate filtered back-projection for reconstructing tomographic data.

A FPGA-BASED PARAMETRIZABLE SYSTEM FOR HIGH-RESOLUTION FREQUENCY-DOMAIN IMAGE FILTERING

2005 ◽  
Vol 14 (05) ◽  
pp. 895-921
Author(s):  
ISA SERVAN UZUN ◽  
ABBES AMIRA
Keyword(s):  
Image Processing ◽  
Frequency Domain ◽  
High Performance ◽  
Fourier Transforms ◽  
Processing System ◽  
Image Filtering ◽  
Input Image ◽  
Frame Rate ◽  
Detailed Knowledge ◽  
Image Size

Signal and image processing applications require high computational power with the ability to experiment different algorithms involving matrix transforms. Reconfigurable hardware devices in the form of Field Programmable Gate Arrays (FPGAs) have been proposed to obtain high performance at an economical price. However, the users must program FPGAs at a very low level and must have a detailed knowledge of the architecture of the device being used. In trying to reconcile the dual requirements of high performance and the ease of development, this paper reports the design and realization of the Fast Fourier Transforms (FFTs) using a FPGA-based environment, which enables system designer to meet different system requirements (i.e., chip area, speed, memory, etc.) for a range of signal processing and imaging applications. The use of the proposed environment has been proven by the developing a high-level FPGA-based parametrizable image processing system for frequency-domain filtering application. The system achieves real-time image filtering performance exceeding those of currently available solutions by an order of magnitude in frame rate and input image size.

scholarly journals Cell shape characterization and classification with discrete Fourier transforms and self-organizing maps

2017 ◽  
Vol 93 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Fabian L. Kriegel ◽  
Ralf Köhler ◽  
Jannike Bayat-Sarmadi ◽  
Simon Bayerl ◽  
Anja E. Hauser ◽  
...  
Keyword(s):  
Cell Shape ◽  
Fourier Transforms ◽  
Self Organizing Maps ◽  
Discrete Fourier Transforms ◽  
Shape Characterization ◽  
Self Organizing

scholarly journals Energy Saving Quantitative Analysis of Passive, Active, and Renewable Technologies in Different Climate Zones

2021 ◽  
Vol 11 (15) ◽  
pp. 7115
Author(s):  
Chul-Ho Kim ◽  
Min-Kyeong Park ◽  
Won-Hee Kang
Keyword(s):  
Renewable Energy ◽  
Energy Consumption ◽  
Energy Saving ◽  
High Performance ◽  
Energy Systems ◽  
Outdoor Air ◽  
Climate Zones ◽  
Renewable Energy Systems ◽  
Active Systems ◽  
High Performance Buildings

The purpose of this study was to provide a guideline for the selection of technologies suitable for ASHRAE international climate zones when designing high-performance buildings. In this study, high-performance technologies were grouped as passive, active, and renewable energy systems. Energy saving technologies comprising 15 cases were categorized into passive, active, and renewable energy systems. EnergyPlus v9.5.0 was used to analyze the contribution of each technology in reducing the primary energy consumption. The energy consumption of each system was analyzed in different climates (Incheon, New Delhi, Minneapolis, Berlin), and the detailed contributions to saving energy were evaluated. Even when the same technology is applied, the energy saving rate differs according to the climatic characteristics. Shading systems are passive systems that are more effective in hot regions. In addition, the variable air volume (VAV) system, combined VAV–energy recovery ventilation (ERV), and combined VAV–underfloor air distribution (UFAD) are active systems that can convert hot and humid outdoor temperatures to create comfortable indoor environments. In cold and cool regions, passive systems that prevent heat loss, such as high-R insulation walls and windows, are effective. Active systems that utilize outdoor air or ventilation include the combined VAV-economizer, the active chilled beam with dedicated outdoor air system (DOAS), and the combined VAV-ERV. For renewable energy systems, the ground source heat pump (GSHP) is more effective. Selecting energy saving technologies that are suitable for the surrounding environment, and selecting design strategies that are appropriate for a given climate, are very important for the design of high-performance buildings globally.

scholarly journals High-Bandpass Filters in Electrocardiography: Source of Error in the Interpretation of the ST Segment

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
F. Buendía-Fuentes ◽  
M. A. Arnau-Vives ◽  
A. Arnau-Vives ◽  
Y. Jiménez-Jiménez ◽  
J. Rueda-Soriano ◽  
...  
Keyword(s):  
Real Time ◽  
Fourier Transforms ◽  
Pass Filter ◽  
Discrete Fourier Transforms ◽  
Real Time Mode ◽  
Asymptomatic Patients ◽  
St Segment ◽  
Coronary Syndromes ◽  
Clinically Significant ◽  
High Pass

Introduction. Artifactual variations in the ST segment may lead to confusion with acute coronary syndromes. Objective. To evaluate how the technical characteristics of the recording mode may distort the ST segment. Material and Method. We made a series of electrocardiograms using different filter configurations in 45 asymptomatic patients. A spectral analysis of the electrocardiograms was made by discrete Fourier transforms, and an accurate recomposition of the ECG signal was obtained from the addition of successive harmonics. Digital high-pass filters of 0.05 and 0.5 Hz were used, and the resulting shapes were compared with the originals. Results. In 42 patients (93%) clinically significant alterations in ST segment level were detected. These changes were only seen in “real time mode” with high-pass filter of 0.5 Hz. Conclusions. Interpretation of the ST segment in “real time mode” should only be carried out using high-pass filters of 0.05 Hz.

scholarly journals Compiler-directed scratchpad memory data transfer optimization for multithreaded applications on a heterogeneous many-core architecture

2021 ◽  
Author(s):  
Xiaohan Tao ◽  
Jianmin Pang ◽  
Jinlong Xu ◽  
Yu Zhu
Keyword(s):  
Energy Consumption ◽  
High Performance ◽  
Scientific Computing ◽  
Data Transfer ◽  
Performance Model ◽  
Experimental Result ◽  
Transfer Model ◽  
Scratchpad Memory ◽  
On Chip ◽  
Many Core

AbstractThe heterogeneous many-core architecture plays an important role in the fields of high-performance computing and scientific computing. It uses accelerator cores with on-chip memories to improve performance and reduce energy consumption. Scratchpad memory (SPM) is a kind of fast on-chip memory with lower energy consumption compared with a hardware cache. However, data transfer between SPM and off-chip memory can be managed only by a programmer or compiler. In this paper, we propose a compiler-directed multithreaded SPM data transfer model (MSDTM) to optimize the process of data transfer in a heterogeneous many-core architecture. We use compile-time analysis to classify data accesses, check dependences and determine the allocation of data transfer operations. We further present the data transfer performance model to derive the optimal granularity of data transfer and select the most profitable data transfer strategy. We implement the proposed MSDTM on the GCC complier and evaluate it on Sunway TaihuLight with selected test cases from benchmarks and scientific computing applications. The experimental result shows that the proposed MSDTM improves the application execution time by 5.49$$\times$$ × and achieves an energy saving of 5.16$$\times$$ × on average.

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