sign function
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PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261213
Author(s):  
Shaofeng Lu ◽  
Yuefeng Lu ◽  
Ying Sun

The determination of the relation between a number and a numerical interval is one of the core problems in the scientific calculation of privacy protection. The calculation of the relationship between two numbers and a numerical interval to protect privacy is also the basic problem of collaborative computing. It is widely used in data queries, location search and other fields. At present, most of the solutions are still fundamentally limited to the integer level, and there are few solutions at the real number level. To solve these problems, this paper first uses Bernoulli inequality generalization and a monotonic function property to extend the solution to the real number level and designs two new protocols based on the homomorphic encryption scheme, which can not only protect the data privacy of both parties involved in the calculation, but also extend the number domain to real numbers. In addition, this paper designs a solution to the confidential cooperative determination problem between real numbers by using the sign function and homomorphism multiplication. Theoretical analysis shows that the proposed solution is safe and efficient. Finally, some extension applications based on this protocol are given.


Author(s):  
Bouiri Abdesselam ◽  
Benoudjafer Cherif ◽  
Boughazi Othmane ◽  
Abdallah Abden ◽  
Chojaa Hamid

<p><span lang="EN-US">Due to drawbacks of classical linear controller like proportional-integral (PI), many studies have been used non-linear controller specially when it comes to robustness, but this is less efficient in sliding mode controller (SM) due to the sign function, this function is known as a problem chattering phenomenon, this main disadvantage it can be compensated by Lyapunov backstepping condition, This paper presents nonlinear power control strategy of the doubly-fed-induction generator (DFIG) for wind application system (WAS) using sliding mode combining with backstepping controller (SM-BS) to control produced statoric powers to mitigate unnecessary chattering effects inherent in traditional SMC, to check the effectiveness of the controller, we compare performance of sliding mode controller and sliding mode controller combining with backstepping (SM-BS) in terms of required reference tracking, robustness under parametric variations of the generator, sensitivity to perturbations and reaction to speed variations under investigating further of the chattering phenomenon.</span></p>


Author(s):  
Junhe Zhao ◽  
Linlin Yang ◽  
Baochang Zhang ◽  
Guodong Guo ◽  
David Doermann

Binary Neural Networks (BNN) are promising machine learning solutions for deployment on resource-limited devices. Recent approaches to training BNNs have produced impressive results, but minimizing the drop in accuracy from full precision networks is still challenging. One reason is that conventional BNNs ignore the uncertainty caused by weights that are near zero, resulting in the instability or frequent flip while learning. In this work, we investigate the intrinsic uncertainty of vanishing near-zero weights, making the training vulnerable to instability. We introduce an uncertainty-aware BNN (UaBNN) by leveraging a new mapping function called certainty-sign (c-sign) to reduce these weights' uncertainties. Our c-sign function is the first to train BNNs with a decreasing uncertainty for binarization. The approach leads to a controlled learning process for BNNs. We also introduce a simple but effective method to measure the uncertainty-based on a Gaussian function. Extensive experiments demonstrate that our method improves multiple BNN methods by maintaining stability of training, and achieves a higher performance over prior arts.


Information ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 297
Author(s):  
Hiroki Okada ◽  
Shinsaku Kiyomoto ◽  
Carlos Cid

TFHE is a fast fully homomorphic encryption scheme proposed by Chillotti et al. in Asiacrypt’ 2018. Integer-wise TFHE is a generalized version of TFHE that can encrypt the plaintext of an integer that was implicitly presented by Chillotti et al., and Bourse et al. presented the actual form of the scheme in CRYPTO’ 2018. However, Bourse et al.’s scheme provides only homomorphic integer additions and homomorphic evaluations of a sign function. In this paper, we construct a technique for operating any 1-variable function in only one bootstrapping of the integer-wise TFHE. For applications of the scheme, we also construct a useful homomorphic evaluation of several integer arithmetics: division, equality test, and multiplication between integer and binary numbers. Our implementation results show that our homomorphic division is approximately 3.4 times faster than any existing work and that its run time is less than 1 second for 4-bit integer inputs.


2021 ◽  
Vol 24 (1) ◽  
pp. 40-51
Author(s):  
Shams Abd Al-Salam Hashim ◽  
Ahmed K. Hammoudi

The main purpose of this paper is to design a robust second order sliding mode controller that can deal with uncertain nonlinear systems. This controller can keep the main advantages of the first order sliding mode controller, such as the ability to make the system asymptotically stable by forcing the error and its derivatives to have a zero value, the simplicity in the operation, and the robustness in the existence of perturbations. In spite of the features that characterize the first order sliding mode controller (1 SMC), it still suffers from the unwanted phenomenon “chattering”, which originates from a discontinuous control part (sign function). In this context, saturation function can be used instead of sign function to reduce this problematic chattering. Different from the saturation function method, the second order sliding mode controller can be used to overcome the chattering; suffered by the first order sliding mode controller and to retain the stability and performance of the system. In this paper, the twisting and the super twisting second-order algorithms of the sliding mode controller were used, and their results were compared with the first order sliding mode controller. So, this subject focused on the chattering problem who suffers from it the 1 SMC and try to reduce it by using the 2 SMC, the uncertain pendulum system was adopted in this work for the purpose of checking the three controllers. The simulations results showed that the second order sliding mode controller has the ability to reduce both the chattering magnitude and the steady state error and achieve an asymptotically stable system. The results were obtained by using MATLAB programming.


2021 ◽  
Vol 31 (08) ◽  
pp. 2150140
Author(s):  
Haikong Lu ◽  
Karthikeyan Rajagopal ◽  
Fahimeh Nazarimehr ◽  
Sajad Jafari

A chaotic system that can show multiscroll and megastable attractors is studied in this paper. Two cases of the system with periodic and quasi-periodic excitations are discussed. Various stabilities of the system determined by changing parameters and initial values are investigated for both cases. In Case-A of the proposed system, multiscroll attractors are shown for the various parameter values. In Case-B with quasi-periodic excitation, the system shows various multiscroll attractors. Dynamical properties of these two cases are studied using the bifurcation diagram and Lyapunov exponents.


Author(s):  
Rena Mamedova (Sarabska)

An early article is devoted to the study of the concept of Eurasianism in the  context of comparative art history. The presented article emphasizes that modern art history requires methodological innovations that will reveal the features not only of the national specifics of music, but also the parameters of its dialogue with other cultures. The article discusses the concept of musical genocide as an analogue of an innate program that determines the vectors of the artistic culture evolution. As a result, it is possible to determine both universal ethnocultural and the specificity of regional conditioned properties of culture. The purpose of the research is to determine the comparative parameters of the Eurasian culture. The research methodology lies in the method of historicism. Of fundamental importance, he can reveal the logic of historical thinking. The prospect of using the method of historicism lies in the possibility of approaching the complex whole of Eurasian culture in its historical movement, in the unity and development of its constituent parts. Behind the variety of manifestations, the main, common lines of the historical development of Eurasia are being built. The scientific novelty of the research undertaken in this article is to form a number of provisions of the comparative analysis. For example, the concept of a gene formula, a typological series. Conclusions. The category of the gene formula formulated in the article is a historically conditioned sign function of culture. The gene formula is generated by the collective experience of the ethnos and has semantic meaning. At the same time, the gene formula defines a specific type of pitch that ensures the vitality of the music and realizes the identity of the culture.


2021 ◽  
Author(s):  
Zhaorui Li ◽  
Bohang Chen ◽  
Huixian Sun ◽  
Guangkai Liu ◽  
Shilei Zhu

Author(s):  
Chong Yang ◽  
Lu Dace ◽  
Wang Hongli

Rotational Inverted Pendulum is a typical nonlinear, unstable and strong coupling system. How to design a control system to restore the equilibrium state quickly and stably is a problem worth studying. High order super twisting sliding mode system has the advantages of traditional sliding mode control system. Super twisting system can elimination control chatter due to the discontinuities of control variable which contain in traditional sliding mode system. The super twisting system is designed. The saturation function replaces the sign function in the super twisting control function to improve the smoothness of the control variable. The simulation shows that this design has excellent precision. Inverted pendulum has smaller movement stroke than traditional super twisting system. Control chatter is also smaller than traditional super twisting system.


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