In this talk, I will present a line of work done at the Image and Video Understanding Lab (IVUL), which focuses on developing deep graph convolutional networks (DeepGCNs). A GCN is a deep learning network that processes generic graph inputs, thus extending the impact of deep learning to irregular grid data including 3D point clouds and meshes, social graphs, protein interaction graphs, etc. By adapting architectural operations from the CNN realm and reformulating them for graphs, we were the first to show that GCNs can go as deep as CNNs. Developing such a high capacity deep learning platform for generic graphs opens up many opportunities for exciting research, which spans applications in the field of computer vision and beyond, architecture design, and theory. In this talk, I will showcase some of the GCN research done at IVUL and highlight some interesting research questions for future work.

Backstepping is a widely applicable control technique based on Lyapunov theory that under rather mild assumptions leads to families of control laws for a large class of nonlinear systems. Focusing on systems of ordinary differential equations, we introduce the basic concept (integrator backstepping), generalize it, among others, to systems in strict feedback form and pure feedback form, which all enjoy an inherent controllability property, captured in the system structure. The course ends with extending the setting to the adaptive backstepping case, resorting to the certainty equivalence principle and Barbalat's lemma. The course is furnished by a series of exercises to let the students gather experience on tailored examples.

Structured media provide the momentum compensation for the scattering of waves. It is well-known that nano-scale modulations of the refractive index may lead to a temporal and spatial control over light propagation. Yet, also engineering the gain and loss profile uncovers analogous shaping effects. However, only the interplay between both the refractive index and gain and loss modulations introduces unidirectionality in light management. Thus, non-Hermitian optics has become one of the most fertile grounds in optics. A generalized Hilbert transform allows tailoring the two quadratures of the complex permittivity to design periodic or disordered non-Hermitian media, holding either global or local unidirectionality following arbitrary vector fields to tailor the flow of light. The method allows restricting the permittivity within realistic values rendering it suitable for applications.

In this talk, Tareq will present his research contributions and future directions to advance some critical IoT-enabling technologies: sensing, localization, and communications. He will demonstrate how we take advantage of structure in sensed-data and sensor arrays. This structure can help mitigate sensing uncertainties, improve localization accuracy, and enhance the performance of communication systems, all while reducing the computational overhead.  The Internet of Things (IoT) has ushered a new era in many fields including retail, medicine, agriculture, and the automotive industry. In fact, it is projected that by 2025, one trillion IoT devices will be deployed worldwide: the equivalent of 1000 devices per person. To reach such a scale, major advancements are needed in various IoT-enabling technologies.

Backstepping is a widely applicable control technique based on Lyapunov theory that under rather mild assumptions leads to families of control laws for a large class of nonlinear systems. Focusing on systems of ordinary differential equations, we introduce the basic concept (integrator backstepping), generalize it, among others, to systems in strict feedback form and pure feedback form, which all enjoy an inherent controllability property, captured in the system structure. The course ends with extending the setting to the adaptive backstepping case, resorting to the certainty equivalence principle and Barbalat's lemma. The course is furnished by a series of exercises to let the students gather experience on tailored examples.

In this talk, we represent recent advances of radio frequency (RF) sensing technology for healthcare, specifically in monitoring human activities inside homes, retirement facilities, and hospitals. Sensing technologies and data analytics are considered powerful tools in efficient indoor monitoring of human activities.  Monitoring of activities of daily living (ADL) can identify falls, which are considered as the leading cause of fatal and non-fatal injuries for people aged 65 and over. It can also detect variants in activity patterns and changes in routines and lifestyle as well as the state of physical, cognitive, and psychological health of the person. In addition to monitoring ADL, RF-based gesture recognition using hands and arms is shown to be an important contactless technology for Man-Machine-Interface (MMI). Adding to the indoor applications, RF-based vital sign monitoring has vast medical use, as respiration and heartbeats are essential diagnostic barometers for many health problems. More recently, RF sensors have also been proposed for gait analysis for rehabilitation and timely diagnosis of many neurological, orthopedic and medical conditions. Changes in gait patterns can also be precursors of falls. In this talk, we present successful examples in each of the above application areas and discuss pertinent open problems worthy of investigations.

This tutorial establishes and promotes the area of dual system functionality, allowing the radar to house voice and data transmission, leading to technological advances in radar and communications systems. The tutorial develops novel signaling schemes for embedding information into the radar pulsed emissions which, in most cases, is blind to the primary radar operation and radar ambiguity function. It considers different antenna configurations, including multiple-input multiple-output (MIMO) radars and shows how to achieve high data rate communications by combining amplitude-shift keying, phase-shift keying, and code shift keying modulations with waveform-diversity and spatial degrees of freedom.

The field of bioelectronics combines the worlds of electronics and biology with the aim of developing new tools for biomedical research and healthcare. The majority of implantable devices are mechanically stiff and the mechanical properties mismatch with soft tissue causes an immune response which results in their rejection from the body. Another limitation is associated with the fact that most devices utilize metal electrodes to record from/stimulate tissue. These electrodes offer limited coupling with ion fluxes used by cells to communicate with each other, resulting in low efficiency. Such challenges can be overcome with the integration of soft, conducting polymers displaying mixed (ionic and electronic) conduction. In this talk, I will present approaches that leverage the properties of organic conducting materials in order to develop bioelectronic devices interfacing with the body. These devices include organic electrochemical transistors for measuring metabolites, neural activity and integrity of cellular layers.

 In this tutorial, we review sparse arrays from the coarray perspective that strives for full augment ability, i.e., maximizing the number of spatial autocorrelation lags. In this respect, we discuss sparse array performance for direction finding and also address the passive and active arrays for stationary and moving platforms.  We then contrast these configurations with sparse arrays that achieve MaxSINR for both narrowband and wideband sources operating in an interference-active environment. The tutorial also considers both single point source and multiple point sources. We cover the two important cases where the array aperture size is constrained and unconstrained and demonstrate optimum performance in both cases. For the former, and with a limited aperture, we introduce a hybrid design that seeks a full augmentable array which at the same time optimizes beamformer performance. The problem is formulated as a quadratically constraint quadratic program, with the cost function penalized with weighted l1-norm squared of the beamformer weight vector. The wideband problem is tackled by two different approaches, one includes a delay line filter implementation and the other one is the DFT approach. 

As autonomy in individual robots becomes advanced, one of the next challenges is to coordinate multiple of such intelligent robots, which are then expected to innovatively transform legacy industries (e.g., warehouse automation, connected-vehicle management, etc.). Towards collaboration of multiple robots, this talk will particularly introduce a game-theoretical framework for clustering a large number of multiple robots and assigning the robot teams to given tasks, where the network of the robots is strongly connected and the individuals are asynchronous. The proposed decentralised algorithm guarantees convergence of selfish agents having social inhibition towards a Nash stable partition (i.e., social agreement) within polynomial time.

In this seminar, I will present our work on manipulating magnetization with acoustic waves. The temporally and spatially varying strain in acoustic waves produces a corresponding change in the local anisotropy of magnetostrictive materials through the Villari effect. This magneto-acoustic coupling may be used for patterning magnetic films and for nonlinear signal processing such as amplification and correlation of spin waves. I will discuss our experiments and results towards these application possibilities, and also present the techniques we have developed to characterize magnetostriction. 

Graduate Seminar Part 2. Fiber-optic distributed acoustic sensor (DAS) and distributed temperature sensor (DTS) are considered important for many applications. It is challenging to design a hybrid DAS-DTS system using the same optical fiber because the operation principles of the two sensors are different. In this talk, we summarize the concept of using the widespread standard multimode fiber (MMF) for simultaneous distributed acoustic and temperature sensing. In particular, we operate the MMF in a quasi-single-mode (QSM) state to simultaneously fulfill the functional requirements of the DAS and DTS. This technique is significant for many industrial applications because it efficiently tackles a long-standing issue in practical implementation. 

Graduate Seminar Part 1. In this talk, catalyst- and mask-free GaN nanowires ensemble were grown by plasma-assisted molecular beam epitaxy (PA-MBE) under nitrogen-rich condition. Prior to optoelectronic device realization, we conducted fundamental studies including diffusion-induced growth mechanisms on various substrates. On bare fused silica substrate, without any buffer layer, hundreds-of-nanometer scale grains of GaN nanowires were examined by SEM and interfaces were investigated by TEM. Despite the poly-crystalline properties of the coalescent columnar GaN layer, each grain showed the preferential orientation along the c-axis growth direction. To provide conductivity and transparency on amorphous fused silica as a thermally durable substrate, transparent conductive oxide (TCO) layers were deposited by RF magnetron sputtering method on a fused silica glass substrate. Next, for the heterogeneous integration toward solar cell application, we introduced n-GaN nanowires as an electron transport layer (ETL) for methylammonium lead iodide (MAPbI3) perovskite solar cells (PSCs). n-GaN nanowires showed high electron mobility and UV blocking characteristics with MAPbI3. Moreover, finite-difference time-domain (FDTD) simulation confirmed that the roughened interfaces of GaN nanowire arrays are helpful for photon recycling. These achievements can open a new pathway for the heterogeneous integration of group-III nitride and perovskite semiconductors and substrate-independent epitaxy.

Robotics is set to play an ever increasingly important role in society, due to its influence in every aspect of life, including medicine and healthcare, manufacturing, services..etc

With the advent of Internet-of-Things (IoT), the conventional radio frequency (RF) communication technology with a congested spectrum of 300 GHz cannot meet the ever-increasing demand for broadband transmission. By exploiting an unlicensed spectrum of ~ 30 PHz, optical wireless communication (OWC) technology is supposed to significantly relieve the load of RF spectrum to support the massive connectivity of IoT devices in the era of fifth-generation networks and beyond. Up to now, continuous breakthroughs in the field of free-space optical communication, visible light communication, and underwater wireless optical communication (UWOC) are laying a solid foundation for the realization of OWC across satellite-air-ground-ocean (SAGO) boundaries, which is expected to considerably accelerate the pace of realizing globally-connected IoT. In this talk, we will briefly introduce the current progress of UWOC research and development toward applications in SAGO OWC.

In this speech, In this speech, Okumura-Hata expressions will be presented for calculating the attenuation of the field strength of mobile communication stations in the megapolis on the example of the capital of Uzbekistan - Tashkent in the frequency bands 900 and 1800 MHz. Expressions allow to take into account factors that affect the signal attenuation in detail. Knowing the levels of the distribution patterns of the field strength in urban environments can correctly determine the number of base stations required to provide high-quality mobile communication. High quality of mobile communications, in turn, creates the best conditions for a quick payback on the development of a mobile network.

Our talk will consider a cloud-enabled system, and will investigate ways of managing its performance through two particular interference mitigation techniques. In the first part of the talk, inspired by the classical information theoretical results on characterizing the interference channel achievable rate region, we will consider rate-splitting (RS) and common message decoding (CMD) schemes. The talk will shed light on ways of tackling two of the underlying optimization problems in this realm.

In this talk, I will address these questions with a focus on smart and multifunctional nanomaterial-based memory devices than can sense different physical qualities of the environment (Memsors) in addition to pressure-driven microfluidic logic gates which can process and analyze non-electronic media in an attempt to explore, enable and empower a wider range of IoT applications.

The emerging need to improve the quality of life for elderly and disabled individuals who rely on wheelchairs for mobility is our motivation for this work. Research on robotics wheelchair covers broad range from motion control, how to control the wheelchair movement, to complete autonomy.

In this talk we will  see patterned ferromagnetic films control of film aspect ratio which changing film demagnetizing fields increasing the ferromagnetic resonance (FMR) frequencies, Physical separation of two domain dynamics viz. domain wall motion and magnetization rotation incorporated with spiral inductors. Measurement results achieved showing 70% boost in inductance at frequencies between 2 GHz - 6 GHz.

In this talk we discuss approaches to low power design for advanced communication and computing platforms. Specifically, we present the concept of cognitive power management, where contrary to common approaches that assume a 100% error free hardware, the algorithm is made aware of the statistical error performance of the underlying hardware platform. By accounting for hardware errors at the system level, the explorable power management design space is significantly expanded, leading to novel power saving schemes that deliver expected application performance at much lower power consumption.  Sample case studies including LTE system design and in-memory computing platforms will be presented and discussed.

Africa has one of the highest inequality factors in the world, reflecting its developed and developing nature. As such it suffers from the traditional “digital divide”, with low internet connectivity reach in rural areas, which is both economic and geographic in nature. In this talk we will summarize recent proposals to bridge the digital divide and offer a South African perspective on the problem. We will cover active research in South Africa on the topic and speculate what the network future in Africa might be.

Although there is a rich history of cross-layer design for embedded computing systems to achieve desired QoS, we are facing ever more challenges from the intertwined goals of energy- efficiency, thermal design constraints, as well as resilience to errors emanating from the application, environment and hardware platforms. We posit that next-generation computing platforms must necessarily deploy intelligent cross-layer design achieved through self-awareness principles inspired by biology and nature.  Such an approach will move us from current strategies (using limited cross-layer coordination) to a holistic cross-layer strategy that enables intelligent cross-layer management policies which can adaptively tune itself based on the current state of the system. The talk will present design exemplars that embrace this intelligent cross-layer approach, and highlight the role of self-awareness in achieving dynamic adaptivity.

As the title suggests, this interaction focuses on three different set-ups of free-space optical (FSO) communication. We will start with the historical background of FSO system and review traditional data transmission techniques for FSO system. In the first set-up, we will discuss a novel modulation scheme for traditional multi-input multi-output configuration, called optical space shift keying (OSSK). Two recent modified versions of OSSK scheme will also be elaborated.

The talk will discuss how recent advances in wireless computing and communication nodes can be harnessed to serve the multitude of deployment scenarios required to empower communities of the future with smart and connected systems. In this talk, we address fundamental questions that should be asked when contemplating future smart and connected systems, namely, How, Where and What? (1) How can we design computing and communication nodes that best utilize resources in a way that is cognizant of both the abilities of the platform, as well as the requirements of the network? (2) Where are the nodes deployed? By understanding the context of deployment, one can architect unique solutions that are currently unimaginable. With the transformation to diverse applications such as body area networking, critical infrastructure monitoring, precision agriculture, autonomous driving, etc., the need for innovative solutions becomes even more amplified. (3) What benefit can be inferred from the data gathered by nodes in the capacity of computing, communication, and sensing?