Deep learning model-aware regulatization with applications to Inverse Problems

There are various inverse problems – including reconstruction problems arising in medical imaging - where one is often aware of the forward operator that maps variables of interest to the observations. It is therefore natural to ask whether such knowledge of the forward operator can be exploited in deep learning approaches increasingly used to solve inverse problems. In this paper, we provide one such way via an analysis of the generalisation error of deep learning approaches to inverse problems. In particular, by building on the algorithmic robustness framework, we offer a generalisation error bound that encapsulates key ingredients associated with the learning problem such as the complexity of the data space, the size of the training set, the Jacobian of the deep neural network and the Jacobian of the composition of the forward operator with the neural network. We then propose a ‘plug-and-play’ regulariser that leverages the knowledge of the forward map to improve the generalization of the network. We likewise also use a new method allowing us to tightly upper bound the Jacobians of the relevant operators that is much more computationally efficient than existing ones. We demonstrate the efficacy of our model-aware regularised deep learning algorithms against other state-of-the-art approaches on inverse problems involving various sub-sampling operators such as those used in classical compressed sensing tasks, image super-resolution problems and accelerated Magnetic Resonance Imaging (MRI) setups

Adaptive Cross-Layer Multipath Routing Protocol for Mobile Ad Hoc Networks

[EN] Mobile ad hoc networks (MANETs) are generally created for temporary scenarios. In such scenarios, where nodes are in mobility, efficient routing is a challenging task. In this paper, we propose an adaptive and cross-layer multipath routing protocol for such changing scenarios. Our routing mechanisms operate keeping in view the type of applications. For simple applications, the proposed protocol is inspired from traditional on-demand routing protocols by searching shortest routes from source to destination using default parameters. In case of multimedia applications, the proposed mechanism considers such routes which are capable of providing more data rates having less packet loss ratio. For those applications which need security, the proposed mechanism searches such routes which are more secure in nature as compared to others. Cross-layer methodology is used in proposed routing scheme so as to exchange different parameters across the protocol stack for better decision-making at network layer. Our approach is efficient and fault tolerant in a variety of scenarios that we simulated and tested.The authors would like to extend their sincere appreciation to the Deanship of Scientific Research at King Saud University for funding this research group no. 037-1435-RG.Iqbal, Z.; Khan, S.; Mehmood, A.; Lloret, J.; Alrajeh, NA. (2016). Adaptive Cross-Layer Multipath Routing Protocol for Mobile Ad Hoc Networks. Journal of Sensors. 2016:1-18. https://doi.org/10.1155/2016/5486437S1182016Abusalah, L., Khokhar, A., & Guizani, M. (2008). A survey of secure mobile Ad Hoc routing protocols. IEEE Communications Surveys & Tutorials, 10(4), 78-93. doi:10.1109/surv.2008.080407Murthy, S., & Garcia-Luna-Aceves, J. J. (1996). An efficient routing protocol for wireless networks. Mobile Networks and Applications, 1(2), 183-197. doi:10.1007/bf01193336Toh, C.-K. (1997). Wireless Personal Communications, 4(2), 103-139. doi:10.1023/a:1008812928561Pearlman, M. R., & Haas, Z. J. (1999). Determining the optimal configuration for the zone routing protocol. IEEE Journal on Selected Areas in Communications, 17(8), 1395-1414. doi:10.1109/49.779922ZHEN, Y., WU, M., WU, D., ZHANG, Q., & XU, C. (2010). Toward path reliability by using adaptive multi-path routing mechanism for multimedia service in mobile Ad-hoc network. The Journal of China Universities of Posts and Telecommunications, 17(1), 93-100. doi:10.1016/s1005-8885(09)60431-3Sivakumar, R., Sinha, P., & Bharghavan, V. (1999). CEDAR: a core-extraction distributed ad hoc routing algorithm. IEEE Journal on Selected Areas in Communications, 17(8), 1454-1465. doi:10.1109/49.779926Zapata, M. G. (2002). Secure ad hoc on-demand distance vector routing. ACM SIGMOBILE Mobile Computing and Communications Review, 6(3), 106-107. doi:10.1145/581291.581312Khan, S., & Loo, J. (2010). Cross Layer Secure and Resource-Aware On-Demand Routing Protocol for Hybrid Wireless Mesh Networks. Wireless Personal Communications, 62(1), 201-214. doi:10.1007/s11277-010-0048-ySharma, V., & Alam, B. (2012). Unicaste Routing Protocols in Mobile Ad Hoc Networks: A Survey. International Journal of Computer Applications, 51(14), 9-18. doi:10.5120/8108-1714Tarique, M., Tepe, K. E., Adibi, S., & Erfani, S. (2009). Survey of multipath routing protocols for mobile ad hoc networks. Journal of Network and Computer Applications, 32(6), 1125-1143. doi:10.1016/j.jnca.2009.07.002Shiwen Mao, Shunan Lin, Yao Wang, Panwar, S. S., & Yihan Li. (2005). Multipath video transport over ad hoc networks. IEEE Wireless Communications, 12(4), 42-49. doi:10.1109/mwc.2005.1497857Li, Z., Chen, Q., Zhu, G., Choi, Y., & Sekiya, H. (2015). A Low Latency, Energy Efficient MAC Protocol for Wireless Sensor Networks. International Journal of Distributed Sensor Networks, 11(8), 946587. doi:10.1155/2015/946587Zheng, Z., Liu, A., Cai, L. X., Chen, Z., & Shen, X. (2016). Energy and memory efficient clone detection in wireless sensor networks. IEEE Transactions on Mobile Computing, 15(5), 1130-1143. doi:10.1109/tmc.2015.2449847Dong, M., Ota, K., Liu, A., & Guo, M. (2016). Joint Optimization of Lifetime and Transport Delay under Reliability Constraint Wireless Sensor Networks. IEEE Transactions on Parallel and Distributed Systems, 27(1), 225-236. doi:10.1109/tpds.2015.2388482Hamrioui, S., Lorenz, P., Lloret, J., & Lalam, M. (2013). A Cross Layer Solution for Better Interactions Between Routing and Transport Protocols in MANET. Journal of Computing and Information Technology, 21(3), 137. doi:10.2498/cit.1002136Sanchez-Iborra, R., & Cano, M.-D. (2014). An approach to a cross layer-based QoE improvement for MANET routing protocols. Network Protocols and Algorithms, 6(3), 18. doi:10.5296/npa.v6i3.5827Cho, J.-H., Swami, A., & Chen, I.-R. (2011). A Survey on Trust Management for Mobile Ad Hoc Networks. IEEE Communications Surveys & Tutorials, 13(4), 562-583. doi:10.1109/surv.2011.092110.0008

Impact Resisting Concrete

Different percentages of polymers have been added to concrete, to evaluate its  impact resistance. Mixes have been made for plain concrete with crushed stone, also plain concrete mixes with round gravel, Concrete mixes with (0.2, 0.85, 1.5 and 2.0) % of Melment to 100 Kg of binder, Concrete mixes with (0.2, 0.5, 0.75 and 1.5) liter of Glenium to 100 Kg of cement and concrete mixes with three sheets of polystyrene and concrete mixes made using polystyrene sheets with 0.85% by weight of Melment. Concrete with polystyrene sheets and Melment gives average compressive strength of 59.3Mpa, tensile strength of 5.8 Mpa and impact strength when the first crack appears was 1486 blows at 28 days. Using 0.85 % of Melment per 100Kg of binder enhance the concrete resistance to Impact. Using 0.5 Liter of Glenium per 100Kg of cement shows good performance of concrete to Impact. Using three layers of Polystyrene sheets with 0.85% of Melment gives high compressive strength and improve the Impact capacity of concrete. Polystyrene sheets increases the adhesive forces between materials in the mix and superplasticizers increases the workability so as to produce self compacting concrete. Keywords: Polystyrene, Melment, Glenium, Impact Strength. Self Compacting Concrete

Performance Optimization of a Blockchain-Enabled Information and Data Exchange Platform for Smart Grids

Data Availability Statement: Not applicable.Copyright © 2023 by the authors. Exchanging information and data within smart grids is crucial to improve interoperability among system users. Traditional cloud-based data exchange schemes are centralized on a single trusted third-party platform. The schemes consequently suffer from single-point failure, a lack of data protection, and uncontrolled access. Blockchain enables data exchange in a decentralised and secure manner. A new platform is proposed in this work for exchanging data within smart grids using blockchain. It allows users to securely exchange data without losing ownership. This platform provides solutions to three critical problems: privacy, scalability, and user ownership. Particularly, the blockchain-based smart contract technology gives participants the programmability to access data. All interactions are authenticated and recorded by the other participants in the tamper-resistant blockchain network. Furthermore, the performance of the proposed blockchain platform is enhanced by integrating it with an artificial neural network (ANN). The proposed method is used to predict the network’s throughput and latency, and the network administrator uses these predicted values to change the network’s settings for a high throughput and low latency. Throughout the results, the proposed model achieves performance improvements in blockchain-enabled information and data exchange and adapts well to the dynamics of smart grids.European Union’s Horizon 2020 research and innovation program under grant agreement No. 774500

Circulating Citrate Is Associated with Liver Fibrosis in Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is associated with mitochondrial damage. Circulating mitochondrial metabolites may be elevated in NAFLD but their associations with liver damage is not known. This study aimed to assess the association of key mitochondrial metabolites with the degree of liver fibrosis in the context of NAFLD and nonalcoholic steatohepatitis (NASH). Cross-sectional analyses were performed on two cohorts of biopsy-proven NAFLD and/or NASH subjects. The association of circulating mitochondrial metabolite concentrations with liver fibrosis was assessed using linear regression analysis. In the single-center cohort of NAFLD subjects (n = 187), the mean age was 54.9 ±13.0 years, 40.1% were female and 86.1% were White. Type 2 diabetes (51.3%), hypertension (43.9%) and obesity (72.2%) were prevalent. Those with high citrate had a higher proportion of moderate/significant liver fibrosis (stage F ≥ 2) (68.4 vs. 39.6%, p = 0.001) and advanced fibrosis (stage F ≥ 3) (31.6 vs. 13.6%, p = 0.01). Citrate was associated with liver fibrosis independent of age, sex, NAFLD activity score and metabolic syndrome (per 1 SD increase: β = 0.19, 95% CI: 0.03–0.35, p = 0.02). This association was also observed in a cohort of NASH subjects (n = 176) (β = 0.21, 95% CI: 0.07–0.36, p = 0.005). The association of citrate with liver fibrosis was observed in males (p = 0.005) but not females (p = 0.41). In conclusion, circulating citrate is elevated and associated with liver fibrosis, particularly in male subjects with NAFLD and NASH. Mitochondrial function may be a target to consider for reducing the progression of liver fibrosis and NASH.</p

Twin reversed arterial perfusion sequence in a monochorionic monoamniotic twin pregnancy: a very rare condition

Background: Twin reversed arterial perfusion sequence (TRAP) is a very rare congenital anomaly. We present sonographic findings of TRAP sequence in the case of a multiparous woman with a monochorionic monoamniotic twin pregnancy who was referred to our unit for blood sugar control. Case presentation: The patient had a history of co-twin demise at 13 weeks of gestation without appropriate fetal surveillance afterwards. We found a monochorionic placentation with a normal appearing pump twin, an abnormal appearing co-twin without obvious cardiac activity and reversed arterial flow toward instead of away from the anomalous acardiac fetus. Therefore, the sonographic diagnosis of TRAP sequence was confirmed. Conclusions: We recommend considering the potential rare complications of monochorionic twin pregnancy which necessitates proper surveillance and intervention to monitor suitable growth of pump twin. © 2020, The Author(s)

Pharmacokinetics of Caffeic Acid from Methanol Seed Extract of Syzygium cumini L in Rats

Purpose: To describe caffeic acid-based pharmacokinetics of methanol extract of seed of Syzygium cumini L. in rats.Methods: A dose of the extract (500 mg, equivalent to 37.135 mg caffeic acid) was administered orally to 6 male Wister rats, weighing 200 ± 10 g. Blood samples (0.5 mL), collected from the tail vein at 0, 15, 30, 60, 120, 240 and 720 min, were processed and analyzed using high performance liquid chromatography and detected with florescent light detector (FLD).Results: Following the administration of the extract, caffeic acid achieved maximum plasma concentration (5.96 ± 0.49 μg/mL) in 1.0 h which was also the time to achieve maximum concentration (Tmax). Mean resident time (MRT) and half-life (t1/2) were 4.092 ± 0.94 h and 0.14 ± 0.01 h, respectively.Conclusion: The results indicate that absorption of caffeic acid from the oral route is fast, but lower amounts are absorbed. The method developed for the extraction of caffeic acid from the plasma and HPLC determination may be useful in establishing phyto-bioequivalence between Syzygium cumini seed products.Keywords: Caffeic acid, Pharmacokinetics, Syzygium cumini, Phytobioequivalence, Absorptio

M-flation: Inflation From Matrix Valued Scalar Fields

We propose an inflationary scenario, M-flation, in which inflation is driven by three $N\times N$ hermitian matrices $\Phi_i, i=1,2,3$. The inflation potential of our model, which is strongly motivated from string theory, is constructed from $\Phi_{i}$ and their commutators. We show that one can consistently restrict the classical dynamics to a sector in which the $\Phi_i$ are proportional to the $N\times N$ irreducible representations of SU(2). In this sector our model effectively behaves as an N-flation model with $3 N^2$ number of fields and the effective inflaton field has a super-Planckian field value. Furthermore, the fine-tunings associated with unnaturally small couplings in the chaotic type inflationary scenarios are removed. Due to the matrix nature of the inflaton fields there are $3N^2-1$ extra scalar fields in the dynamics. These have the observational effects such as production of iso-curvature perturbations on cosmic microwave background. Moreover, the existence of these extra scalars provides us with a natural preheating mechanism and exit from inflation. As the effective inflaton field can traverse super-Planckian distances in the field space, the model is capable of producing a considerable amount of gravity waves that can be probed by future CMB polarization experiments such as PLANCK, QUIET and CMBPOL.Comment: minor changes, the counting of the alpha and beta modes are corrected, references adde