Reconfigurable data parallel constant geometry fast Fourier transform architectures on Network-on-Chip

اختصاصی از هایدی Reconfigurable data parallel constant geometry fast Fourier transform architectures on Network-on-Chip دانلود با لینک مستقیم و پر سرعت .

Reconfigurable data parallel constant geometry fast Fourier transform
architectures on Network-on-Chip

ژورنال:Microprocessors and Microsystems

سال:November 2015

قیمت اصلی:35.95$

Abstract

This paper reports the design and development of reconfigurable (up to 8192-point), data parallel, constant geometry fast Fourier transform (CG-FFT) architectures based on Network-on-Chip (NoC) paradigm. Twiddle factor multiplications have been realized using pipelined CORDIC rotators in the proposed architecture in order to ensure its high throughput. Mapping of FFT functions to cores has been done by considering the proposed signal flow graph (SFG) for CG-FFT architecture, which helps in optimizing the design of network components (routers and network interfaces) and reducing the latency of FFT computation. The proposed input-size aware architecture can withstand faults in other processing elements (PEs) as it can accomplish the entire FFT computation using only one PE as well. When mapped onto mesh based NoC, the proposed architectures could achieve reduction in latency by 5×, compared to several existing FFT architectures on NoC. Hardware realization of the PE and the network components of the proposed architectures have been done using Xilinx Kintex-7 family field-programmable gate array (FPGA) device. The maximum operating frequency of a PE in the proposed architecture has been found to be 184.010 MHz, which meets the timing specifications of several application standards, such as DVB-T/H, DAB, 802.11a/n and UWB. In addition to the FPGA-prototype, the proposed architectures have also been synthesized in ASIC design flow to obtain area and power results.

Keywords

• Constant geometry, Fast Fourier transform, FPGA,
• Network-on-Chip, Reconfigurable architecture

Tartaric acid assisted hydrothermal synthesis of different flower-like ZnO hierarchical architectures with tunable optical and

اختصاصی از هایدی Tartaric acid assisted hydrothermal synthesis of different flower-like ZnO hierarchical architectures with tunable optical and oxygen vacancy-induced photocatalytic properties دانلود با لینک مستقیم و پر سرعت .

Tartaric acid assisted hydrothermal synthesis of different flower-like ZnO hierarchical architectures with tunable optical and oxygen vacancy-induced photocatalytic properties

ژورنال:Applied Surface Science

سال: December 2015

قیمت اصلی:35.95$

Abstract

Different flower-like ZnO hierarchical architectures were prepared by tartaric acid assisted hydrothermal synthesis, especially four flower-like ZnO nanostructures were obtained simultaneously under the same reaction condition. The cauliflower-like ZnO is assembled by spherical shaped nanoparticles, and the chrysanthemum-like and other flower-like ZnO nanostructures are assembled by hexagonal rods/prisms with from planar to semi-pyramid, and to pyramid tips. TA acts as a capping agent and structure-directing agent during the synthesis. All ZnO possess the hexagonal wurtzite structure. The PL spectra can be tuned by changing TA concentration. XRD, PL and Raman spectra confirmed that oxygen vacancies mainly come from the ZnO surface. The flower-like samples of 1:4.5 and 1:3 with the largest aspect ratios have highest photocatalytic performance. They decompose 85% MB within 60 min. Combining PL Gaussian fitting with K, the higher content of oxygen vacancy is, the higher photocatalytic activity is. The enhanced photocatalytic performance is mainly induced by oxygen vacancy of ZnO. The possible formation mechanism, growth and change process of flower-like ZnO were proposed.

Keywords

• ZnO hierarchical architectures, Hydrothermal synthesis, Flower-like,Optical property,
• Photocatalytic performance