Characterizations and Quantifications of Macroscopic Quantumness and Its Implementations using Optical Fields

We present a review and discussions on characterizations and quantifications of macroscopic quantum states as well as their implementations and applications in optical systems. We compare and criticize different measures proposed to define and quantify macroscopic quantum superpositions and extend such comparisons to several types of optical quantum states actively considered for experimental implementations within recent research topics.Comment: 13 pages, 2 figures, references added, review article to be published in the Special Issue of Optics Communications on Macroscopic Quantumness: Theory and Applications in Optical Science

System and Thermal Modeling of Hydraulic Hybrids: Thermal Characteristics Analysis

Hybrid vehicles have become a popular alternative to conventional powertrain architectures by offering improved fuel efficiency along with various other environmental benefits. Among them, hydraulic hybrid vehicles (HHVs) have several benefits, which make it the superior technology for certain applications over other types of hybrid vehicles, such as lower component costs, more environmentally friendly construction materials, higher power densities, and more regenerative energy available from braking. There have been various studies on HHVs, such as energy management optimization, control strategies for various system configurations, the effect of system parameters on the hybrid system, and proposals for novel hybrid architectures. One area not been thoroughly covered in the past is a detailed modeling and examination of the thermal characteristics for HHVs due to a difficulty of describing the rapid thermal transients in the unsteady state systems. In this dissertation, a comprehensive system and thermal modeling has been studied for hydraulic hybrid transmissions (HHTs). The main motivation behind developing a thermal model of HHTs is to gain a deeper understanding of the system’s thermal performance, and key influencing factors, without relying on experimental data. This will enable HHVs to be designed more efficiently by identifying and addressing potential issues with transmission’s thermal performance prior to hardware testing. Since there exists no thermal study on HHVs in the past, a thermal modeling method has been introduced, which can be applicable to hydraulic hybrid architectures. A thermal modeling methodology based on a novel numerical scheme and accurate theoretical description has been developed in order to capture the rapid thermal transient in the hydraulic system under unsteady state conditions. The model has been applied to a series HHT and validated with measured data from the hardware-in-the-loop (HIL) test rig with a standard driving cycle, FTP-72. In addition, the proposed thermal modeling methodology has been used to analyze and optimize the cooling system of a novel HHV architecture, which is implemented in a sport utility vehicle (SUV) in Maha Fluid Power Research Center. The modeling results have been compared with the measured data while driving the vehicle. In both studies, the simulation results have shown a good correlation with the experimental data in terms of the overall trends and variation ranges. The goal of the developed model is the application to the system and thermal issues in HHVs, such as thermal stability analysis, management of the cooling system, packaging and hydraulic component optimization, and evaluation of thermal characteristics of different architectures. As an advanced topic of this research, thermal management of an open and a closed circuit hydraulic hybrid systems has been studied by simulation. The comparison results show a potential to a better thermal management for the open circuit systems with smaller heat exchangers, as well as less power consumption with incorporation of smaller charge pumps compared to the closed circuit systems. In the future, the developed comprehensive system and thermal modeling method can be applied to different advanced topics, such as analysis of performance and thermal characteristics, systems and components optimization, and systems evaluation with different external conditions, for different hydraulic hybrid systems

Universal Auto-encoder Framework for MIMO CSI Feedback

Existing auto-encoder (AE)-based channel state information (CSI) frameworks have focused on a specific configuration of user equipment (UE) and base station (BS), and thus the input and output sizes of the AE are fixed. However, in the real-world scenario, the input and output sizes may vary depending on the number of antennas of the BS and UE and the allocated resource block in the frequency dimension. A naive approach to support the different input and output sizes is to use multiple AE models, which is impractical for the UE due to the limited HW resources. In this paper, we propose a universal AE framework that can support different input sizes and multiple compression ratios. The proposed AE framework significantly reduces the HW complexity while providing comparable performance in terms of compression ratio-distortion trade-off compared to the naive and state-of-the-art approaches.Comment: 7 pages, 11 figure