Internet of Things and its enhanced data security

The Internet of Things (IoT), an emerging global Internet-based technical architecture facilitating the exchange of information, goods and services in the internet world has an impact on the security and privacy of the involved stakeholders. Measures ensuring the architectures resilience to attacks, data authentication, and access control and client privacy need to be established. This paper includes a survey of IoT and various security issues related to it. Furthermore, out of all security issues, concern over data authentication and transfer is taken into consideration. Here we will discuss the idea for two levels of security in form of two different approaches i.e. Advance Encryption Standards (AES) and the Steganography approach via an image and the simulating of these two logics in the MATLAB

Design of Small Scale Anaerobic Digester for Application in Indian Village: A Review

Proper choosing of design of anaerobic digester and estimation of it size is an important point in the successful implementation of anaerobic digester. The end users of anaerobic digester in most cases are farmers whose technical knowledge of the systems is limited. And there is a lack of information available on design methods for these systems. The goals of this study were to develop literature that could be used by laymen to decide the design and size of anaerobic digester. To develop a design formula that could be used for anaerobic digester sizing based on livestock waste availability. The case studies were conducted on three scales: one household, six households, and a village of 67 and 28 households. The biogas produced in case study for one household was0.44 m3, for six household was 2.60 m3, for Kapurpur village of 67 household was 11.33 m3

Effect of scouring in sand on monopile supported offshore wind turbines

This paper analyzes the influence of scour on the overall response of monopile-supported offshore wind turbines (OWTs) in 20-m water depth. Scouring effects on OWTs have been often studied within the geotechnical domain, considering static loads at the mudline. The present work attempts to address the scour-induced problems in OWTs by making use of an integrated aerodynamic–hydrodynamic load approach in sandy soils. The OWT analysis is simulated for operational and shut-down (parked) condition. Under parked situations, the OWT blades are feathered, and power production is suspended, owing to structural safety concerns. The 50 Monte Carlo responses of stochastic sea-state condition (wind speed with turbulence, significant wave height, and peak spectral period) are generated. Irregular, long-crested waves are generated using the Joint North Sea Wave Project (JONSWAP) spectrum. Then from each simulation, the ensemble response is obtained. Sandy soils of varying densities are considered. Results indicate that OWTs founded on loose sands suffer significant stiffness (and hence natural frequency) reductions, shifting the structure into the resonance regime. Lateral responses also show an escalation with reduction in density of sandy soil

Dynamic analysis of monopile supported offshore wind turbines

This paper describes the stochastic dynamic response of National Renewable Energy Laboratory 5 MW offshore fixedbased wind turbine (OWT) under various soil conditions – medium dense sand, stiff clay and layered profiles in 20 m depth of water. The aerodynamic and hydrodynamic OWT loads are derived using the force-controlled approach. Usually the OWT generates power in an operational regime and survives at extreme wind speeds. Therefore, two met-ocean conditions adhering to the irregular Joint North Sea Wave Project spectrum are considered – one in an operational regime (average wind speed Vw = 12 m/s, significant wave height Hs = 4 m and peak spectral period Tp= 10 s) and another in a near cut-out regime (Vw = 22 m/s, Hs = 10 m, Tp = 14 s). The soil is modelled by way of a non-linear ground-to-spring model. For each sea state, time domain stochastic responses are calculated and the ensemble average response is calculated from 50 Monte-Carlo simulations. The change in ensemble average response due to changes in pile penetration depth and diameter of the piles for the three soil configurations is described. Results indicate that the dynamic response mainly depends on the stiffness of the soil and reiterate the need for detailed site-specific geotechnical investigations before designing OWT foundations

Need for objective task-based evaluation of AI-based segmentation methods for quantitative PET

Artificial intelligence (AI)-based methods are showing substantial promise in segmenting oncologic positron emission tomography (PET) images. For clinical translation of these methods, assessing their performance on clinically relevant tasks is important. However, these methods are typically evaluated using metrics that may not correlate with the task performance. One such widely used metric is the Dice score, a figure of merit that measures the spatial overlap between the estimated segmentation and a reference standard (e.g., manual segmentation). In this work, we investigated whether evaluating AI-based segmentation methods using Dice scores yields a similar interpretation as evaluation on the clinical tasks of quantifying metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of primary tumor from PET images of patients with non-small cell lung cancer. The investigation was conducted via a retrospective analysis with the ECOG-ACRIN 6668/RTOG 0235 multi-center clinical trial data. Specifically, we evaluated different structures of a commonly used AI-based segmentation method using both Dice scores and the accuracy in quantifying MTV/TLG. Our results show that evaluation using Dice scores can lead to findings that are inconsistent with evaluation using the task-based figure of merit. Thus, our study motivates the need for objective task-based evaluation of AI-based segmentation methods for quantitative PET

Coupling between feedback loops in autoregulatory networks affects bistability range, open-loop gain and switching times

Biochemical regulatory networks governing diverse cellular processes such as stress-response, differentiation and cell cycle often contain coupled feedback loops. We aim at understanding how features of feedback architecture, such as the number of loops, the sign of the loops and the type of their coupling, affect network dynamical performance. Specifically, we investigate how bistability range, maximum open-loop gain and switching times of a network with transcriptional positive feedback are affected by additive or multiplicative coupling with another positive- or negative-feedback loop. We show that a network's bistability range is positively correlated with its maximum open-loop gain and that both quantities depend on the sign of the feedback loops and the type of feedback coupling. Moreover, we find that the addition of positive feedback could decrease the bistability range if we control the basal level in the signal-response curves of the two systems. Furthermore, the addition of negative feedback has the capacity to increase the bistability range if its dissociation constant is much lower than that of the positive feedback. We also find that the addition of a positive feedback to a bistable network increases the robustness of its bistability range, whereas the addition of a negative feedback decreases it. Finally, we show that the switching time for a transition from a high to a low steady state increases with the effective fold change in gene regulation. In summary, we show that the effect of coupled feedback loops on the bistability range and switching times depends on the underlying mechanistic details