scholarly journals A Novel Method to Decrease Electric Field and SAR Using an External High Dielectric Sleeve at 3 T Head MRI: Numerical and Experimental Results

2015 ◽  
Vol 62 (4) ◽  
pp. 1063-1069 ◽  
Author(s):  
Bu S. Park ◽  
Sunder S. Rajan ◽  
Joshua W. Guag ◽  
Leonardo M. Angelone

Author(s):  
Bu S. Park ◽  
Joshua W. Guag ◽  
Leonardo M. Angelone ◽  
Sunder S. Rajan

We present experimental and numerical simulation results showing that high dielectric materials (HDMs) located outside of a RF head coil decrease the electric field (E-field, |E|) with minimum change of the RF magnetic field (B1+) at 3T MRI imaging. Compared to previous research using HDMs located between the RF coil and sample, our method locating the HDM outside the coil allowed an increased sample size and more flexibility of HDM thickness optimization. Numerical simulation results showed more than 30% decrease in the local SAR at the boundary region of the head model. Validating experimental results showed a 21% decrease in the maximum |Etotal| using a HDM made of distilled water.





Author(s):  
Seiji Nomura ◽  
Kosaku Kurata ◽  
Hiroshi Takamatsu

The irreversible electroporation (IRE) is a novel method to ablate abnormal cells by applying a high voltage between two electrodes that are stuck into abnormal tissues. One of the advantages of the IRE is that the extracellular matrix (ECM) may be kept intact, which is favorable for healing. For a successful IRE, it is therefore important to avoid thermal damage of ECM resulted from the Joule heating within the tissue. A three-dimensional (3-D) analysis was conducted in this study to predict temperature rise during the IRE. The equation of electric field and the heat conduction equation were solved numerically by a finite element method. It was clarified that the highest temperature rise occurred at the base of electrodes adjacent to the insulated surface. The result was significantly different from a two-dimensional (2-D) analysis due to end effects, suggesting that the 3-D analysis is required to determine the optimal condition.



Author(s):  
Qing Li ◽  
F.C. Sun

A novel method to detect vehicles is presented in the paper. Assumption of the vehicle is made using the geometrical features of the vehicle rear by the statistical histogram. Then hypothesis is verified using the property of the shadow cast by the car according to a prior acknowledgement of traffic scene. Finally, the vehicle detection is realized by hypothesis and verification of objects. The experimental results show the efficiency and feasibility of the method.



Author(s):  
M.H.A. Wahab ◽  
N. A. M. Jamail ◽  
E. Sulaiman ◽  
Q.E. Kamarudin ◽  
N.A. Othman ◽  
...  

<p>Nowadays, XLPE cable has been widely used because it has better resistance than other cables. XLPE insulation has unique features including a high dielectric strength and high insulation resistance. A lot of researches based on hardware and software have been conducted to prove the effectiveness of XLPE cable such as AC and DC applications and Space Charge Distribution measurement under HVDC at High Temperature. This research focused on analysis of space charge and electric field on XLPE cable with effect of non-uniform contamination layer by using Quickfield Software. Non-uniform contaminations have been applied along XLPE cable using Arsenic Tribromide (AsBr3), Boron Bromide (BBr3), Ethylene Dichloride (CH2C1), Formic Acid (CH1O2), Formamide (CH3NO) and Alcohol element. Presence of these contamination elements represent of underground contamination. The size and layer of the contamination were non-uniform type. From the results, it is shown that lower dielectric constant of contamination will affect more on charge of XLPE insulation. As a conclusion, it can be seen lower dielectric constant value of contamination element greatly affecting the performance of XLPE insulation. Furthermore, size of contamination also influences the content of charge in contamination where the bigger the contamination size, the more charge contained in the contamination.</p>



Author(s):  
Loránd Lehel Tóth ◽  
Raymond Pardede ◽  
Gábor Hosszú

The article presents a method to decipher Rovash inscriptions made by the Szekelys in the 15th-18th centuries. The difficulty of the deciphering work is that a large portion of the Rovash inscriptions contains incomplete words, calligraphic glyphs or grapheme errors. Based on the topological parameters of the undeciphered symbols registered in the database, the presented novel algorithm estimates the meaning of the inscriptions by the matching accuracies of the recognized graphemes and gives a statistical probability for deciphering. The developed algorithm was implemented in software, which also contains a built-in dictionary. Based on the dictionary, the novel method takes into account the context in identifying the meaning of the inscription. The proposed algorithm offers one or more words in a different random values as a result, from which users can select the relevant one. The article also presents experimental results, which demonstrate the efficiency of method.



Author(s):  
Changdong Xu ◽  
Xin Geng

Hierarchical classification is a challenging problem where the class labels are organized in a predefined hierarchy. One primary challenge in hierarchical classification is the small training set issue of the local module. The local classifiers in the previous hierarchical classification approaches are prone to over-fitting, which becomes a major bottleneck of hierarchical classification. Fortunately, the labels in the local module are correlated, and the siblings of the true label can provide additional supervision information for the instance. This paper proposes a novel method to deal with the small training set issue. The key idea of the method is to represent the correlation among the labels by the label distribution. It generates a label distribution that contains the supervision information of each label for the given instance, and then learns a mapping from the instance to the label distribution. Experimental results on several hierarchical classification datasets show that our method significantly outperforms other state-of-theart hierarchical classification approaches.



2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Xueping Su ◽  
Meng Gao ◽  
Jie Ren ◽  
Yunhong Li ◽  
Matthias Rätsch

With the continuous development of economy, consumers pay more attention to the demand for personalization clothing. However, the recommendation quality of the existing clothing recommendation system is not enough to meet the user’s needs. When browsing online clothing, facial expression is the salient information to understand the user’s preference. In this paper, we propose a novel method to automatically personalize clothing recommendation based on user emotional analysis. Firstly, the facial expression is classified by multiclass SVM. Next, the user’s multi-interest value is calculated using expression intensity that is obtained by hybrid RCNN. Finally, the multi-interest value is fused to carry out personalized recommendation. The experimental results show that the proposed method achieves a significant improvement over other algorithms.



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