scholarly journals Non-contact PIM Measurement Method for Antenna using High-level IM Standard

Author(s):  
Masayoshi Kuwata ◽  
Nobuhiro kuga

<p>A non-contact passive intermodulation distortion (PIM) measurement method for antenna using high-level IM standard (HIMS) is described as proposed herein. A novel method to estimate coupling loss between sensing antenna and a sample antenna is proposed, after which a complete one-port non-contact measurement for antenna is realized. Measurements are conducted in three stages: measuring IM characteristics of HIMS, estimating coupling loss using HIMS, and estimating practical PIM level of a sample antenna. A high-level IM standard consisting of a Schottky barrier diode was used for this study. The method enables ready evaluation of practical PIM of a sample antenna from a complete one-port non-contact measurement with excellent stability and repeatability. Then the validity of the proposed method was confirmed experimentally using a printed dipole antenna. After presenting an applicable measurement method for array antenna incorporating the proposed method, its effectiveness was verified experimentally.</p>

2021 ◽  
Author(s):  
Masayoshi Kuwata ◽  
Nobuhiro kuga

<p>A non-contact passive intermodulation distortion (PIM) measurement method for antenna using high-level IM standard (HIMS) is described as proposed herein. A novel method to estimate coupling loss between sensing antenna and a sample antenna is proposed, after which a complete one-port non-contact measurement for antenna is realized. Measurements are conducted in three stages: measuring IM characteristics of HIMS, estimating coupling loss using HIMS, and estimating practical PIM level of a sample antenna. A high-level IM standard consisting of a Schottky barrier diode was used for this study. The method enables ready evaluation of practical PIM of a sample antenna from a complete one-port non-contact measurement with excellent stability and repeatability. Then the validity of the proposed method was confirmed experimentally using a printed dipole antenna. After presenting an applicable measurement method for array antenna incorporating the proposed method, its effectiveness was verified experimentally.</p>


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ha Min Son ◽  
Wooho Jeon ◽  
Jinhyun Kim ◽  
Chan Yeong Heo ◽  
Hye Jin Yoon ◽  
...  

AbstractAlthough computer-aided diagnosis (CAD) is used to improve the quality of diagnosis in various medical fields such as mammography and colonography, it is not used in dermatology, where noninvasive screening tests are performed only with the naked eye, and avoidable inaccuracies may exist. This study shows that CAD may also be a viable option in dermatology by presenting a novel method to sequentially combine accurate segmentation and classification models. Given an image of the skin, we decompose the image to normalize and extract high-level features. Using a neural network-based segmentation model to create a segmented map of the image, we then cluster sections of abnormal skin and pass this information to a classification model. We classify each cluster into different common skin diseases using another neural network model. Our segmentation model achieves better performance compared to previous studies, and also achieves a near-perfect sensitivity score in unfavorable conditions. Our classification model is more accurate than a baseline model trained without segmentation, while also being able to classify multiple diseases within a single image. This improved performance may be sufficient to use CAD in the field of dermatology.


1999 ◽  
Vol 354 (1379) ◽  
pp. 153-159 ◽  
Author(s):  
Anne C. Stone ◽  
Mark Stoneking

The Norris Farms No. 36 cemetery in central Illinois has been the subject of considerable archaeological and genetic research. Both mitochondrial DNA (mtDNA) and nuclear DNA have been examined in this 700–year–old population. DNA preservation at the site was good, with about 70% of the samples producing mtDNA results and approximately 15% yielding nuclear DNA data. All four of the major Amerindian mtDNA haplogroups were found, in addition to a fifth haplogroup. Sequences of the first hypervariable region of the mtDNA control region revealed a high level of diversity in the Norris Farms population and confirmed that the fifth haplogroup associates with Mongolian sequences and hence is probably authentic. Other than a possible reduction in the number of rare mtDNA lineages in many populations, it does not appear as if European contact significantly altered patterns of Amerindian mtDNA variation, despite the large decrease in population size that occurred. For nuclear DNA analysis, a novel method for DNA–based sex identification that uses nucleotide differences between the X and Y copies of the amelogenin gene was developed and applied successfully in approximately 20 individuals. Despite the well–known problems of poor DNA preservation and the ever–present possibility of contamination with modern DNA, genetic analysis of the Norris Farms No. 36 population demonstrates that ancient DNA can be a fruitful source of new insights into prehistoric populations.


2018 ◽  
Vol 246 ◽  
pp. 03020
Author(s):  
Tan Wei ◽  
Xuan Liu ◽  
Chen Yi ◽  
Erfu Yang

With the development of industrial automation, location measurement of 3D objects is becoming more and more important, especially as it can provide necessary positional parameters for the manipulator to grasp the object accurately. In view of the disabled object which is in widespread use currently, its image is captured to obtain positional parameters and transmitted to manipulators in industry. The above process is delayed, affecting the work efficiency of the manipulator. A method for calculating the position information of target object in motion is proposed. This method uses monocular vision technology to track 3D moving objects,then uses contour sorting method to extract the minimum constrained contour rectangle, and combines the video alignment technology to realize the tracking. Thus, the measurement error is reduced. The experimental results and analysis show that the adopted measurement method is effective.


EP Europace ◽  
2017 ◽  
Vol 20 (1) ◽  
pp. 149-156 ◽  
Author(s):  
René van Es ◽  
John Hauck ◽  
Vincent J H M van Driel ◽  
Kars Neven ◽  
Harry van Wessel ◽  
...  

Author(s):  
Shang Liu ◽  
Xiao Bai

In this chapter, the authors present a new method to improve the performance of current bag-of-words based image classification process. After feature extraction, they introduce a pairwise image matching scheme to select the discriminative features. Only the label information from the training-sets is used to update the feature weights via an iterative matching processing. The selected features correspond to the foreground content of the images, and thus highlight the high level category knowledge of images. Visual words are constructed on these selected features. This novel method could be used as a refinement step for current image classification and retrieval process. The authors prove the efficiency of their method in three tasks: supervised image classification, semi-supervised image classification, and image retrieval.


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