scholarly journals High-Precision Sub-Nyquist Sampling System Based on Modulated Wideband Converter for Communication Device Testing

2021 ◽  
pp. 1-11
Author(s):  
Zolboo Byambadorj ◽  
Koji Asami ◽  
Takahiro J. Yamaguchi ◽  
Akio Higo ◽  
Masahiro Fujita ◽  
...  
Keyword(s):  
High Precision ◽  
Sampling System ◽  
Communication Device ◽  
Modulated Wideband Converter

scholarly journals Atmospheric Fossil Fuel CO2 Measurement Using a Field Unit in a Central European City During the Winter of 2008/09

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 835-845 ◽  
Author(s):  
M Molnár ◽  
L Haszpra ◽  
É Svingor ◽  
I Major ◽  
I Svetlik
Keyword(s):  
High Precision ◽  
Fossil Fuel ◽  
Rural Site ◽  
Mixing Ratio ◽  
European City ◽  
Sampling System ◽  
Central European ◽  
Mixing Ratios ◽  
Clean Air ◽  
Field Unit

A high-precision atmospheric CO2 monitoring station was developed as a field unit. Within this, an integrating CO2 sampling system was applied to collect samples for radiocarbon measurements. One sampler was installed in the second largest city of Hungary (Debrecen station) and 2 independent 14CO2 sampling lines were installed ∼300 km from Debrecen in a rural site at Hegyhátsál station as independent background references, where high-precision atmospheric CO2 mixing ratios have been measured since 1994. Fossil fuel CO2 content in the air of the large Hungarian city of Debrecen was determined during the winter of 2008 using both the measurements of CO2 mixing ratio and 14C content of air. Fossil fuel CO2 was significantly enhanced at Debrecen relative to the clean-air site at Hegyhátsál.

Design and Realization of Resolution Detection System for AD7730

2012 ◽  
Vol 241-244 ◽  
pp. 190-193
Author(s):  
Xiao Ming Chang ◽  
Bin Sun ◽  
Shi Xuan Yao
Keyword(s):  
Instrument Development ◽  
High Precision ◽  
Virtual Instrument ◽  
Detection System ◽  
Performance Parameter ◽  
Analog Signal ◽  
Sampling System ◽  
Development Environment ◽  
Signal Sampling ◽  
Application System

Before using high-precision ADC AD7730 in analog signal sampling system, it’s required to measure the actual resolution if needed. This paper introduces the design of resolution detection system for ADC, which is used to evaluate the resolution performance parameter of ADC. First, a framework of the application system is designed, and specified at the example of 24bit ADC AD7730 application based on the Virtual Instrument Development Environment LabVIEW. Finally, actual resolutions of input channels are given and evaluated.

Analysis and Signal Recovery of Modulated Wideband Converter with Gain Mismatch

2013 ◽  
Vol 284-287 ◽  
pp. 2609-2614 ◽  
Author(s):  
You Hua Wang ◽  
Jian Qiu Zhang
Keyword(s):  
Signal Reconstruction ◽  
Reconstruction Algorithm ◽  
Signal Recovery ◽  
Sampling System ◽  
Error Matrix ◽  
Gain Variation ◽  
Gain Error ◽  
Low Pass ◽  
Modulated Wideband Converter ◽  
Low Pass Filters

Recently, a sub-Nyquist sampling system, called as Modulated Wideband Converter (MWC), for sparse analog signals is proposed in [1]. In this paper, the gain mismatch, i.e. the gain variation of the mixers, the low pass filters and the low-date rate ADCs, in the MWC is, firstly, analyzed. A gain error matrix defined to model the gain mismatch is, then, proposed to formulate all of these non-idealities of the gains. Based on the gain error matrix, a more accurate signal reconstruction algorithm is presented. Numerical simulation results show that the proposed signal reconstruction algorithm outperforms the reference algorithm in the presence of gain mismatch, while the analytical results are verified.

Automatic measurement of SAED patterns from asbestos minerals

1988 ◽  
Vol 46 ◽  
pp. 846-847
Author(s):  
J. C. Russ ◽  
T. Taguchi ◽  
P. M. Peters ◽  
E. Chatfield ◽  
J. C. Russ ◽  
...  
Keyword(s):  
Diffraction Pattern ◽  
High Precision ◽  
Diffraction Data ◽  
Automatic Measurement ◽  
Automatic Method ◽  
Important Method ◽  
X Ray ◽  
Integrated Intensity ◽  
Asbestiform Minerals ◽  
True Center

Conventional SAD patterns as obtained in the TEM present difficulties for identification of materials such as asbestiform minerals, although diffraction data is considered to be an important method for making this purpose. The preferred orientation of the fibers and the spotty patterns that are obtained do not readily lend themselves to measurement of the integrated intensity values for each d-spacing, and even the d-spacings may be hard to determine precisely because the true center location for the broken rings requires estimation. We have implemented an automatic method for diffraction pattern measurement to overcome these problems. It automatically locates the center of patterns with high precision, measures the radius of each ring of spots in the pattern, and integrates the density of spots in that ring. The resulting spectrum of intensity vs. radius is then used just as a conventional X-ray diffractometer scan would be, to locate peaks and produce a list of d,I values suitable for search/match comparison to known or expected phases.

On effects of non-systematic reflections on weak-beam images of partial dislocations

1991 ◽  
Vol 49 ◽  
pp. 688-689
Author(s):  
K. Z. Botros ◽  
S. S. Sheinin
Keyword(s):  
High Precision ◽  
Stacking Fault ◽  
Important Application ◽  
Stacking Fault Energy ◽  
Sharp Peak ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Deviation Parameter ◽  
Beam Diffraction

The main features of weak beam images of dislocations were first described by Cockayne et al. using calculations of intensity profiles based on the kinematical and two beam dynamical theories. The feature of weak beam images which is of particular interest in this investigation is that intensity profiles exhibit a sharp peak located at a position very close to the position of the dislocation in the crystal. This property of weak beam images of dislocations has an important application in the determination of stacking fault energy of crystals. This can easily be done since the separation of the partial dislocations bounding a stacking fault ribbon can be measured with high precision, assuming of course that the weak beam relationship between the positions of the image and the dislocation is valid. In order to carry out measurements such as these in practice the specimen must be tilted to "good" weak beam diffraction conditions, which implies utilizing high values of the deviation parameter Sg.

Digital differential hysteresis iimage processing displays what the microscope acquires but the eye can't see

1995 ◽  
Vol 53 ◽  
pp. 642-643
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
Image Processing ◽  
Visual System ◽  
High Precision ◽  
Image Data ◽  
Processing Technology ◽  
Output Data ◽  
Contrast Resolution ◽  
Pixel Intensity ◽  
Data Reading ◽  
Hysteresis Properties

Differential hysteresis processing is a new image processing technology that provides a tool for the display of image data information at any level of differential contrast resolution. This includes the maximum contrast resolution of the acquisition system which may be 1,000-times higher than that of the visual system (16 bit versus 6 bit). All microscopes acquire high precision contrasts at a level of <0.01-25% of the acquisition range in 16-bit - 8-bit data, but these contrasts are mostly invisible or only partially visible even in conventionally enhanced images. The processing principle of the differential hysteresis tool is based on hysteresis properties of intensity variations within an image.Differential hysteresis image processing moves a cursor of selected intensity range (hysteresis range) along lines through the image data reading each successive pixel intensity. The midpoint of the cursor provides the output data. If the intensity value of the following pixel falls outside of the actual cursor endpoint values, then the cursor follows the data either with its top or with its bottom, but if the pixels' intensity value falls within the cursor range, then the cursor maintains its intensity value.

The Evolution of Augmentative Communication and the Importance of Alternate Access

2011 ◽  
Vol 20 (1) ◽  
pp. 34-37 ◽  
Author(s):  
David Chapple
Keyword(s):  
Augmentative And Alternative Communication ◽  
Cell Phone ◽  
Handheld Devices ◽  
Alternative Communication ◽  
Access Methods ◽  
The Past ◽  
Communication Device ◽  
Internet Browser ◽  
A Cell ◽  
Development Of Language

Abstract Over the past 20 years, there have been many advances in the computer industry as well as in augmentative and alternative communication (AAC) devices. Computers are becoming more compact and have multiple purposes, such as the iPhone, which is a cell phone, mp3 player, and an Internet browser. AAC devices also have evolved to become multi-purpose devices; the most sophisticated devices have functionality similar to the iPhone and iPod. Recently, the idea of having the iPhone and iPad as a communication device was initiated with the development of language applications specifically for this format. It might be true that this idea could become the future of AAC devices; however, there are major access issues to overcome before the idea is a reality. This article will chronicle advancements in AAC devices, specifically on access methods, throughout the years, towards the transition to handheld devices. The newest technologies hold much promise with both features and affordability factors being highly attractive. Yet, these technologies must be made to incorporate alternate access if they are to meet their fullest potential as AAC tools.

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