On the geometry of fixed points and discontinuity
Year 2024,
, 155 - 170, 29.02.2024
Rajendra Prasad Pant
,
Nihal Özgür
,
Bharti Joshı
,
Mangey Ram
Abstract
Recently, there has been a considerable effort to obtain new solutions to the Rhoades' open problem on the existence of contractive mappings that admit discontinuity at the fixed point. An extended version of this problem is also stated using a geometric approach. In this paper, we obtain new solutions to this extended version of the Rhoades' open problem. A related problem, the fixed-circle problem (resp. fixed-disc problem) is also studied. Both of these problems are related to the geometric properties of the fixed point set of a self-mapping on a metric space. Furthermore, a new result about metric completeness and a short discussion on the activation functions used in the study of neural networks are given. By providing necessary examples, we show that our obtained results are effective.
References
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$(\epsilon -\delta)$ contractions and applications to neural networks, Aequationes Math. 94 (5),
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Appl. Gen. Topol. 18 (1), 173-182, 2017.
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Rend. Circ. Mat. Palermo (2) 69 (1), 21-28, 2020.
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the Data Sciences. Springer, Cham. 2020.
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Turkish J. Math. 44 (4), 1115-1126, 2020.
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fractional-order bidirectional associative memory neural networks with discontinuous
activations: state feedback control and impulsive control schemes, Proc. R. Soc. A
473 (2204), 20170322, 21 pp, 2017.
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Cohen-Grossberg neural networks with discontinuous activation functions, Discrete
Dyn. Nat. Soc. 2013, 917835, 11 pp, 2013.
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neuron activations, IEEE Trans. Circuits Syst. I, Fundam. Theory Appl. 50 (11),
1421-1435, 2003.
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recurrent neural networks with discontinuous and nonmonotonic activation functions,
IEEE Access 7, 116430-116437, 2019.
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associative memory neural networks with discontinuous activation functions,
Appl. Math. Comput. 219 (3), 899-910, 2012.
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advanced contractions on $F$-metric space, J. Appl. Anal. Comput. 10 (6), 2313-2322,
2020.
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Axioms, 8 (2), 72, 2019.
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activation function for quadratic programming, IEEE Transactions on Neural
Networks 19 (4), 558-570, 2008.
- [16] N. Mlaiki, U. Çelik, N. Tas, N. Y. Özgür and A. Mukheimer, Wardowski type contractions
and the fixed-circle problem on S-metric spaces, J. Math. 2018, 9127486, 9
pp, 2018.
- [17] X. Nie, J. Liang and J. Cao, Multistability analysis of competitive neural networks
with Gaussian-wavelet-type activation functions and unbounded time-varying delays,
Appl. Math. Comput. 356, 449-468, 2019.
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piecewise linear activation functions and time-varying delays, Neural Networks
65, 65-79, 2015.
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nonmonotonic piecewise linear activation functions, IEEE Trans. Neural
Netw. Learn. Syst. 26 (11), 2901-2913, 2015.
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neural networks with discontinuous nonmonotonic piecewise linear activation functions,
IEEE Transactions On Cybernatics 46 (3), 679-693, 2015.
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activation functions, in: 4th Australian Control Conference (AUCC), IEEE,
245-250, 2014.
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infection detection based on deep features and Bayesian optimization, Applied Soft
Computing, 97, 106580, 2020.
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2805, 2019.
- [24] N. Özgür and N. Tas, New discontinuity results at fixed point on metric spaces, J.
Fixed Point Theory Appl. 23 (2), 28, 14 pp, 2021.
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Math. Sci. Soc. 42 (4), 1433-1449, 2019.
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viewpoint, Facta Univ. Ser. Math. Inform. 34 (3), 459-472, 2019.
- [27] N. Y. Özgür and N. Tas, Some fixed-circle theorems and discontinuity at fixed circle,
AIP Conf. Proc. 1926 (1), 020048, 2018.
- [28] N. Y. Özgür and N. Tas, Generalizations of metric spaces: from the fixed-point theory
to the fixed-circle theory, in: Rassias T. (eds) Applications of Nonlinear Analysis.
Springer Optim. Appl. 134, Springer, Cham 2018.
- [29] R. P. Pant, Discontinuity and fixed points, J. Math. Anal. Appl. 240 (1), 284-289,
1999.
- [30] R. P. Pant, N. Y. Özgür and N. Tas, On discontinuity problem at fixed point, Bull.
Malays. Math. Sci. Soc. 43 (1), 499-517, 2020.
- [31] R. P. Pant, N. Y. Özgür and N. Tas, Discontinuity at fixed points with applications,
Bull. Belg. Math. Soc.-Simon Stevin 26 (4), 571-589, 2019.
- [32] R. P. Pant, N. Özgür, N. Tas, A. Pant and M. C. Joshi, New results on discontinuity
at fixed point, J. Fixed Point Theory Appl. 22 (2), 39, 14 pp, 2020.
- [33] A. Pant and R. P. Pant, Fixed points and continuity of contractive maps, Filomat 31
(11), 3501-3506, 2017.
- [34] A. Pant, R. P. Pant, V. Rakocevic and R. K. Bisht, Generalized Meir-Keeler Type
Contractions and Discontinuity at Fixed Point II, Math. Slovaca 69 (6), 1501-1507,
2019.
- [35] S. Pourbahrami, L. M. Khanli, and S. Azimpour, An Automatic Clustering of Data
Points with Alpha and Beta Angles on Apollonius and Subtended Arc Circle based
on Computational Geometry, in: 28th Iranian Conference on Electrical Engineering
(ICEE), IEEE 1-6, 2020.
- [36] D. Reem and S. Reich, Fixed points of polarity type operators, J. Math. Anal. Appl.
467 (2), 1208-1232, 2018.
- [37] B. E. Rhoades, Contractive definitions and continuity, Contemp. Math. 72, 233-245,
1988.
- [38] H. N. Saleh, S. Sessa, W. M. Alfaqih, M. Imdad and N. Mlaiki, Fixed circle and fixed
disc results for new types of $\Theta c$-contractive mappings in metric spaces, Symmetry 12
(11), 1825, 2020.
- [39] S. Sharma, S. Sharma and A. Athaiya, Activation functions in neural networks, Int.
J. Adv. Eng. Sci. Appl. Math. 4 (12), 310-316, 2020.
- [40] K. K. Singh, M. Siddhartha and A. Singh, Diagnosis of coronavirus disease (COVID-
19) from chest X-ray images using modified XceptionNet, Romanian J. Inf. Sci. Technol.
23 (657), 91-105, 2020.
- [41] R. G. Singh and A. P. Singh, Multiple complex extreme learning machine using holomorphic
mapping for prediction of wind power generation system, Int. J. Comput.
Appl. 123 (18), 24-33, 2015.
- [42] P. V. Subrahmanyam, Completeness and fixed-points, Monatsh. Math. 80 (4), 325-
330, 1975.
- [43] N. Tas and N. Özgür, New fixed-figure results on metric spaces, in: Debnath, P.,
Srivastava, H.M., Kumam, P., Hazarika, B. (eds) Fixed Point Theory and Fractional
Calculus, Forum for Interdisciplinary Mathematics, Springer, Singapore, 2022.
- [44] N. Tas and N. Y. Özgür, A new contribution to discontinuity at fixed point, Fixed
Point Theory 20 (2), 715-728, 2019.
- [45] N. Tas, N. Y. Özgür and N. Mlaiki, New types of Fc-contractions and the fixed-circle
problem, Mathematics 6, 188, 2018.
- [46] A. Tomar, M. Joshi and S. K. Padaliya, Fixed point to fixed circle and activation
function in partial metric space, J. Appl. Anal. 28 (1), 57-66, 2022.
- [47] H. Wu and C. Shan, Stability analysis for periodic solution of BAM neural networks
with discontinuous neuron activations and impulses, Appl. Math. Modelling 33 (6),
2564-2574, 2017.
- [48] L. Zhang, Implementation of fixed-point neuron models with threshold, ramp and sigmoid
activation functions, in: IOP Conference Series: Materials Science and Engineering
224 (19), 012054, IOP Publishing, 2017.
- [49] H. Zhang, Z. Wang and D. Liu, A comprehensive review of stability analysis of
continuous-time recurrent neural networks, IEEE Trans. Neural Netw. Learn. Syst.
25 (7), 1229-1262, 2014.
- [50] D. Zheng and P. Wang, Weak $\theta $-$\phi $-contractions and discontinuity, J. Nonlinear Sci.
Appl. 10, 2318-2323, 2017.
Year 2024,
, 155 - 170, 29.02.2024
Rajendra Prasad Pant
,
Nihal Özgür
,
Bharti Joshı
,
Mangey Ram
References
- [1] H. Baghani, A new contractive condition related to Rhoades’ open question, Indian J.
Pure Appl. Math. 51 (2), 565-578, 2020.
- [2] R. K. Bisht and N. Özgür, Geometric properties of discontinuous fixed point set of
$(\epsilon -\delta)$ contractions and applications to neural networks, Aequationes Math. 94 (5),
847-863, 2020.
- [3] R. K. Bisht and R. P. Pant, A remark on discontinuity at fixed points, J. Math. Anal.
Appl. 445 (2), 1239-1242, 2017.
- [4] R. K. Bisht and R. P. Pant, Contractive definitions and discontinuity at fixed point,
Appl. Gen. Topol. 18 (1), 173-182, 2017.
- [5] R. K. Bisht and V. Rakocevic, Fixed points of convex and generalized convex contractions,
Rend. Circ. Mat. Palermo (2) 69 (1), 21-28, 2020.
- [6] O. Calin, Activation Functions, in: Deep Learning Architectures. Springer Series in
the Data Sciences. Springer, Cham. 2020.
- [7] U. Çelik and N. Özgür, A new solution to the discontinuity problem on metric spaces,
Turkish J. Math. 44 (4), 1115-1126, 2020.
- [8] X. Ding, J. Cao, X. Zhao and F. E. Alsaadi, Mittag-Leffler synchronization of delayed
fractional-order bidirectional associative memory neural networks with discontinuous
activations: state feedback control and impulsive control schemes, Proc. R. Soc. A
473 (2204), 20170322, 21 pp, 2017.
- [9] Y. Du, Y. Li and R. Xu, Multistability and multiperiodicity for a general class of delayed
Cohen-Grossberg neural networks with discontinuous activation functions, Discrete
Dyn. Nat. Soc. 2013, 917835, 11 pp, 2013.
- [10] M. Forti and P. Nistri, Global convergence of neural networks with discontinuous
neuron activations, IEEE Trans. Circuits Syst. I, Fundam. Theory Appl. 50 (11),
1421-1435, 2003.
- [11] Y. Huang, X. Yuan, H. Long, X. Fan and T. Cai, Multistability of fractional-order
recurrent neural networks with discontinuous and nonmonotonic activation functions,
IEEE Access 7, 116430-116437, 2019.
- [12] Y. Huang, H. Zhang and Z. Wang, Multistability and multiperiodicity of delayed bidirectional
associative memory neural networks with discontinuous activation functions,
Appl. Math. Comput. 219 (3), 899-910, 2012.
- [13] A. Hussain, H. Al-Sulami, N. Hussain, and H. Farooq, Newly fixed disc results using
advanced contractions on $F$-metric space, J. Appl. Anal. Comput. 10 (6), 2313-2322,
2020.
- [14] E. Karapınar, Recent advances on the results for nonunique fixed in various spaces,
Axioms, 8 (2), 72, 2019.
- [15] Q. Liu and J. Wang, A one-layer recurrent neural network with a discontinuous hardlimiting
activation function for quadratic programming, IEEE Transactions on Neural
Networks 19 (4), 558-570, 2008.
- [16] N. Mlaiki, U. Çelik, N. Tas, N. Y. Özgür and A. Mukheimer, Wardowski type contractions
and the fixed-circle problem on S-metric spaces, J. Math. 2018, 9127486, 9
pp, 2018.
- [17] X. Nie, J. Liang and J. Cao, Multistability analysis of competitive neural networks
with Gaussian-wavelet-type activation functions and unbounded time-varying delays,
Appl. Math. Comput. 356, 449-468, 2019.
- [18] X. Nie and W. X. Zheng, Multistability of neural networks with discontinuous nonmonotonic
piecewise linear activation functions and time-varying delays, Neural Networks
65, 65-79, 2015.
- [19] X. Nie and W. X. Zheng, Multistability and instability of neural networks with discontinuous
nonmonotonic piecewise linear activation functions, IEEE Trans. Neural
Netw. Learn. Syst. 26 (11), 2901-2913, 2015.
- [20] X. Nie and W. X. Zheng, Dynamical behaviors of multiple equilibria in competitive
neural networks with discontinuous nonmonotonic piecewise linear activation functions,
IEEE Transactions On Cybernatics 46 (3), 679-693, 2015.
- [21] X. Nie and W. X. Zheng, On multistability of competitive neural networks with discontinuous
activation functions, in: 4th Australian Control Conference (AUCC), IEEE,
245-250, 2014.
- [22] M. Nour, Z. Cömert and K. Polat, A novel medical diagnosis model for COVID-19
infection detection based on deep features and Bayesian optimization, Applied Soft
Computing, 97, 106580, 2020.
- [23] N. Özgür, Fixed-disc results via simulation functions, Turkish J. Math. 43 (6), 2794-
2805, 2019.
- [24] N. Özgür and N. Tas, New discontinuity results at fixed point on metric spaces, J.
Fixed Point Theory Appl. 23 (2), 28, 14 pp, 2021.
- [25] N. Y. Özgür and N. Tas, Some fixed-circle theorems on metric spaces, Bull. Malays.
Math. Sci. Soc. 42 (4), 1433-1449, 2019.
- [26] N. Y. Özgür and N. Tas, Fixed-circle problem on S-metric spaces with a geometric
viewpoint, Facta Univ. Ser. Math. Inform. 34 (3), 459-472, 2019.
- [27] N. Y. Özgür and N. Tas, Some fixed-circle theorems and discontinuity at fixed circle,
AIP Conf. Proc. 1926 (1), 020048, 2018.
- [28] N. Y. Özgür and N. Tas, Generalizations of metric spaces: from the fixed-point theory
to the fixed-circle theory, in: Rassias T. (eds) Applications of Nonlinear Analysis.
Springer Optim. Appl. 134, Springer, Cham 2018.
- [29] R. P. Pant, Discontinuity and fixed points, J. Math. Anal. Appl. 240 (1), 284-289,
1999.
- [30] R. P. Pant, N. Y. Özgür and N. Tas, On discontinuity problem at fixed point, Bull.
Malays. Math. Sci. Soc. 43 (1), 499-517, 2020.
- [31] R. P. Pant, N. Y. Özgür and N. Tas, Discontinuity at fixed points with applications,
Bull. Belg. Math. Soc.-Simon Stevin 26 (4), 571-589, 2019.
- [32] R. P. Pant, N. Özgür, N. Tas, A. Pant and M. C. Joshi, New results on discontinuity
at fixed point, J. Fixed Point Theory Appl. 22 (2), 39, 14 pp, 2020.
- [33] A. Pant and R. P. Pant, Fixed points and continuity of contractive maps, Filomat 31
(11), 3501-3506, 2017.
- [34] A. Pant, R. P. Pant, V. Rakocevic and R. K. Bisht, Generalized Meir-Keeler Type
Contractions and Discontinuity at Fixed Point II, Math. Slovaca 69 (6), 1501-1507,
2019.
- [35] S. Pourbahrami, L. M. Khanli, and S. Azimpour, An Automatic Clustering of Data
Points with Alpha and Beta Angles on Apollonius and Subtended Arc Circle based
on Computational Geometry, in: 28th Iranian Conference on Electrical Engineering
(ICEE), IEEE 1-6, 2020.
- [36] D. Reem and S. Reich, Fixed points of polarity type operators, J. Math. Anal. Appl.
467 (2), 1208-1232, 2018.
- [37] B. E. Rhoades, Contractive definitions and continuity, Contemp. Math. 72, 233-245,
1988.
- [38] H. N. Saleh, S. Sessa, W. M. Alfaqih, M. Imdad and N. Mlaiki, Fixed circle and fixed
disc results for new types of $\Theta c$-contractive mappings in metric spaces, Symmetry 12
(11), 1825, 2020.
- [39] S. Sharma, S. Sharma and A. Athaiya, Activation functions in neural networks, Int.
J. Adv. Eng. Sci. Appl. Math. 4 (12), 310-316, 2020.
- [40] K. K. Singh, M. Siddhartha and A. Singh, Diagnosis of coronavirus disease (COVID-
19) from chest X-ray images using modified XceptionNet, Romanian J. Inf. Sci. Technol.
23 (657), 91-105, 2020.
- [41] R. G. Singh and A. P. Singh, Multiple complex extreme learning machine using holomorphic
mapping for prediction of wind power generation system, Int. J. Comput.
Appl. 123 (18), 24-33, 2015.
- [42] P. V. Subrahmanyam, Completeness and fixed-points, Monatsh. Math. 80 (4), 325-
330, 1975.
- [43] N. Tas and N. Özgür, New fixed-figure results on metric spaces, in: Debnath, P.,
Srivastava, H.M., Kumam, P., Hazarika, B. (eds) Fixed Point Theory and Fractional
Calculus, Forum for Interdisciplinary Mathematics, Springer, Singapore, 2022.
- [44] N. Tas and N. Y. Özgür, A new contribution to discontinuity at fixed point, Fixed
Point Theory 20 (2), 715-728, 2019.
- [45] N. Tas, N. Y. Özgür and N. Mlaiki, New types of Fc-contractions and the fixed-circle
problem, Mathematics 6, 188, 2018.
- [46] A. Tomar, M. Joshi and S. K. Padaliya, Fixed point to fixed circle and activation
function in partial metric space, J. Appl. Anal. 28 (1), 57-66, 2022.
- [47] H. Wu and C. Shan, Stability analysis for periodic solution of BAM neural networks
with discontinuous neuron activations and impulses, Appl. Math. Modelling 33 (6),
2564-2574, 2017.
- [48] L. Zhang, Implementation of fixed-point neuron models with threshold, ramp and sigmoid
activation functions, in: IOP Conference Series: Materials Science and Engineering
224 (19), 012054, IOP Publishing, 2017.
- [49] H. Zhang, Z. Wang and D. Liu, A comprehensive review of stability analysis of
continuous-time recurrent neural networks, IEEE Trans. Neural Netw. Learn. Syst.
25 (7), 1229-1262, 2014.
- [50] D. Zheng and P. Wang, Weak $\theta $-$\phi $-contractions and discontinuity, J. Nonlinear Sci.
Appl. 10, 2318-2323, 2017.