Towards sustainable smart cities: A review of trends, architectures, components, and open challenges in smart cities

Internet of Things security

The surge in global population is compelling a shift toward smart agriculture practices. This coupled with the diminishing natural resources, limited availability of arable land, increase in unpredictable weather conditions makes food security a major concern for most countries. As a result, the use of Internet of Things (IoT) and data analytics (DA) are employed to enhance the operational efficiency and productivity in the agriculture sector. There is a paradigm shift from use of wireless sensor network (WSN) as a major driver of smart agriculture to the use of IoT and DA. The IoT integrates several existing technologies, such as WSN, radio frequency identification, cloud computing, middleware systems, and end-user applications. In this paper, several benefits and challenges of IoT have been identified. We present the IoT ecosystem and how the combination of IoT and DA is enabling smart agriculture. Furthermore, we provide future trends and opportunities which are categorized into technological innovations, application scenarios, business, and marketability.

An Overview of Internet of Things (IoT) and Data Analytics in Agriculture: Benefits and Challenges

Internet of Things (IoT) technology has attracted much attention in recent years for its potential to alleviate the strain on healthcare systems caused by an aging population and a rise in chronic illness. Standardization is a key issue limiting progress in this area, and thus this paper proposes a standard model for application in future IoT healthcare systems. This survey paper then presents the state-of-the-art research relating to each area of the model, evaluating their strengths, weaknesses, and overall suitability for a wearable IoT healthcare system. Challenges that healthcare IoT faces including security, privacy, wearability, and low-power operation are presented, and recommendations are made for future research directions.

Internet of Things for Smart Healthcare: Technologies, Challenges, and Opportunities

https://digitalcommons.uri.edu/cgi/viewcontent.cgi?article=1069&context=ele_facpubs

Towards fog-driven IoT eHealth: Promises and challenges of IoT in medicine and healthcare

In molecular communication, some molecules stay longer in the medium and impinge on later transmissions. The bit error rate (BER) of a diffusion-based molecular communication channel which has memory is analysed. The effect of four previous symbols on the current symbol is considered. Human insulin hormone is used as the messenger molecule and the first passage time of a molecule has been defined as the delay. Channel memory has been found to have a profound influence on the BER.

Effect of memory on BER in molecular communication


 Of late, inorganic perovskite material, especially the lead-free CsGeBr3, has gained considerable interest in the green photovoltaic industry due to its outstanding optoelectronic, thermal, and elastic properties. In this work, we systematically investigated the strain-driven optical, electronic, and mechanical properties of CsGeBr3 through the first-principles density functional theory. The unstrained planar CsGeBr3 compound demonstrates a direct bandgap of 0.92 eV at its R-point. However, by incorporating external biaxial tensile (compressive) strain the bandgap lowering (increasing) can be tuned to this perovskite. Moreover, due to the increase of tensile (compressive) strain, a red-shift (blue-shift) behavior of the absorption-coefficient and dielectric function is found in the photon energy spectrum. Strain-induced mechanical properties also reveal that CsGeBr3 perovskites are mechanically stable and highly ductile material and can be made suitable for photovoltaic applications. The strain-dependent optoelectronic and mechanical behaviors of CsGeBr3 explored here would be beneficial for its future applications in optoelectronics and photovoltaic cells design.

Strain-Driven Optical, Electronic, and Mechanical Properties of Inorganic Halide Perovskite CsGeBr3

Low power UWB receiver architecture is proposed for a Wireless Body Area Network (WBAN). This receiving technology is a synergy of existing downconversion-based narrowband rejection mechanism in RF front end and signal processing in frequency domain. Frequency components of converted and filtered UWB pulses are separated into real and imaginary parts, independently correlated and effectively combined to achieve an improved output Signal to noise ratio (SNR). An extensive mathematical analysis has been performed to formulate the close-form expressions for SNRs in order to compare system performances toward favorable BER under BPSK modulation scheme. Analysis shows that optimal rotation of coordination plays an important role for the enhancement of receiving SNR which is further confirmed by computer simulation. A wide range of link level simulation (LLS) urges that the proposed system is more power efficient in higher-order modulation (HOM) schemes. Transmitted Reference (TR) scheme has been considered as the basis for wideband communication.

/pdf/a-tr-uwb-downconversion-autocorrelation-receiver-for-1w1fjzxl1o.pdf

A TR-UWB downconversion autocorrelation receiver for wireless body area network

The Wireless Personal Area Network (WPAN) is one of the fledging paradigms that the next generation of wireless systems is sprouting towards. Among them, a more specific category is the Wireless Body Area Network (WBAN) used for health monitoring. On the other hand, Ultra-Wideband (UWB) comes with a number of desirable features at the physical layer for wireless communications. One big challenge in adoption of UWB in WBAN is the fact that signals get attenuated exponentially. Due to the intrinsic structural complexity in human body, electromagnetic waves show a profound variation during propagation through it. The reflection and transmission coefficients of human body are highly dependent upon the dielectric constants as well as upon the frequency. The difference in structural materials such as fat, muscles and blood essentially makes electromagnetic wave attenuation to be different along the way. Thus, a complete characterization of body channel is a challenging task. The connection between attenuation and frequency of the signal makes the investigation of UWB in WBAN an interesting proposition. In this paper, we study analytically the impact of body channels on electromagnetic signal propagation with reference to UWB. In the process, scattering, reflectivity and transmitivity have been addressed with analysis of approximate layer-wise modeling, and with numerical depictions. Pulses with Gaussian profile have been employed in our analysis. It shows that, under reasonable practical approximations, the human body channel can be modeled in layers so as to have the effects of total reflections or total transmissions in certain frequency bands. This could help decide such design issues as antenna characteristics of implant devices for WBAN employing UWB.

/pdf/studies-of-scattering-reflectivity-and-transmitivity-in-wban-58p5q775qa.pdf

Md. Humaun Kabir

Papers

Effect of memory on BER in molecular communication

Strain-Driven Optical, Electronic, and Mechanical Properties of Inorganic Halide Perovskite CsGeBr3

A TR-UWB downconversion autocorrelation receiver for wireless body area network

Studies of Scattering, Reflectivity, and Transmitivity in WBAN Channel: Feasibility of Using UWB

Design and Implementation of Web-based Smart Class Routine Management System for Educational Institutes