Terms Of Design Complexity Research Articles

A comparative investigation of two-phase immersion thermal management system for lithium-ion battery pack

The applications of lithium-ion batteries (LIBs) still suffer from thermal sensitivity and safety issues, especially given the rigorous requirements of fast charging and discharging. When choosing a proper battery thermal management system (BTMS), a comprehensive investigation should be made in terms of design complexity, system cost, and cooling efficiency, which usually forms a trade-off. In this study, four types of BTMS including air cooling, single phase immersion, indirect cooling, and two phase immersion are first evaluated on pouch battery pack. To describe the uniform heat generation, batteries are simulated by a three-dimensional electrochemical-thermal coupled model. Results show that air cooling and immersion cooling exhibits less extra weight, while two phase immersion delivers better in suppressing temperature rise and maintaining temperature uniformity. Then, the simulations involving different coolants are conducted for two phase immersion-based BTMS. The thermal behaviors of battery pack are examined at 5, 7, and 9 C discharge rates. The R1336mzz(Z) coolant with high boiling heat transfer coefficient is suitable for thermal management at high discharge rates. Besides, analysis reveals that increasing the immersion level of battery pack can improve battery temperature behaviors. This work is expected to provide preliminary proof of BTMS design for fast discharging.

Design of an efficient routing algorithm on the WK-recursive network

The WK-recursive network proposed by Vecchia and Sanges[1] is widely used in the design and implementation of local area networks and parallel processing architectures. It provides a high degree of regularity and scalability, which conform well to a design and realization of distributed systems involving a large number of computing elements. In this paper, the routing of a message is investigated on the WK-recursive network, which is key to the performance of this network. We present an efficient shortest path algorithm on the WK-recursive network, which is simpler than Chen and Duh[2] in terms of design complexity.

Hybrid Beamforming for MISO System via Convolutional Neural Network

Hybrid beamforming (HBF) is a promising approach to obtain a better balance between hardware complexity and system performance in massive MIMO communication systems. However, the HBF optimization problem is a challenging task due to its nonconvex property in terms of design complexity and spectral efficiency (SE) performance. In this work, a low-complexity convolutional neural network (CNN)-based HBF algorithm is proposed to solve the SE maximization problem under the constant modulus constraint and transmit power constraint in a multiple-input single-output (MISO) system. The proposed CNN framework uses multiple convolutional blocks to extract more channel features. Considering that the solutions for the HBF are hard to obtain, we derive an unsupervised learning mechanism to avoid any labeled data when training the constructed CNN. We discuss the performance of the proposed algorithm in terms of both the generalization ability for multiple CSIs and the specific solving ability for an individual CSI, respectively. Simulations show its advantages in both SE and complexity over other related algorithms.

Multi-input interleaved DC-DC converter for hybrid renewable energy applications

The increasing demand for hybrid energy systems based on renewable energy sources has enabled the new dimension for multi-input converter (MIC). Various topologies have been introduced over the last decade. However, most of these topologies have several drawbacks in terms of design complexity or efficiency. Therefore, this research aims to introduce a multi-input DC-DC converter for hybrid renewable energy applications. The proposed multi-input converter is able to hybridize different sources such as solar PV array and PEMFC. Analysis and simulation have been carried out for the double input two-phase interleaved converter in operating the boost mode. The proposed converter is designed in matlab simulink by using interleaved boost converter method to achieve a boosted and smoothened output. The proposed topology has shown a remarkable performance in terms of output voltage boosting, voltage ripple reduction as well as enhanced efficiency through interleaved boosting technique. From the simulation results, it can be observed that the proposed converter can gain high efficiency which is higher than 97%. The obtained results have been validated with previously published works and the proposed technique has been proven to yield compatible and improved outcomes.

Design of Bilayer and Multi-Layer LDPC Ensembles From Individual Degree Distributions

A new approach for designing bilayer and multi-layer LDPC codes is proposed and studied in the asymptotic regime. The ensembles are defined through individual uni-variate degree distributions, one for each layer. We present a construction that: 1) enables low-complexity decoding for high-SNR channel instances, 2) provably approaches capacity for low-SNR instances, 3) scales linearly (in terms of design complexity) in the number of layers. For the setup where decoding the second layer is significantly more costly than the first layer, we propose an optimal-cost decoding schedule and study the trade-off between code rate and decoding cost.

A comprehensive review: metrology in additive manufacturing and 3D printing technology

Additive manufacturing (AM) is making a big leap in the manufacturing technology world primarily due to its unique capability to produce parts in a layer-by-layer fashion from the digital 3D model with immense versatility in terms of design complexity. In addition, AM does not require any additional tooling and can produce parts with minimal to no material loss. Despite these technological advantages, AM is not making inroads to its potential, mainly due to a lack of fundamental understanding of all the AM processes and cohesive efforts in standardization, metrology (the science of measurement), qualification and certification. As a result, AM produces parts with higher complexity and features yet lacking dimensional accuracy, precision, the required level of tolerances and intended material properties. Particularly, the process-specific standardized metrology and inspection methods for the parts made by AM play a major role in imparting the desired quality and subsequently facilitate the process of certification of the AM part. Considering this, the present article provides (1) a comprehensive review of generic metrology and in-situ, real-time inspection methods that are currently utilized for the parts produced from conventional manufacturing processes in use, as well as (2) a comprehensive review of metrology and in-situ, real-time inspection methods currently and/or may be utilized for the parts produced from AM processes. In addition to these, the appropriate metrology and inspection methods are recommended here for various AM processes. NSWC Corona, the leading agency for the U.S. Navy’s Metrology and Calibration (METCAL) program, is playing an important role towards addressing these AM metrology challenges.

Polarimetric Calibration of RISAT-1 Compact-Pol Data

India's radar imaging satellite RISAT-1 was the first spaceborne SAR platform operated in the compact polarimetric (CP) mode, which posed several advantages compared to the commonly used quad-pol system architecture in terms of design complexity and data quality. But, to make use of the advantages offered by the compact polarimetry mode, the acquired datasets should be free from the system induced polarimetric distortions, which include the channel imbalances, phase bias, and crosstalk between the channels. In addition to these system induced errors, the ionosphere also induces polarimetric distortion to the datasets in terms of Faraday rotation. For accurate ground target characterization using the CP datasets, the polarimetric distortions should be estimated and minimized. This article focuses on the CP calibration of the RISAT-1 dataset using trihedral and dihedral corner reflectors deployed at the study area. The Cloude CP decomposition technique is used to assess the ground target characterization quality of the dataset before and after polarimetric calibration.

Energy Efficient Single-Ended 6-T SRAM for Multimedia Applications

Image processing and other multimedia applications require large embedded storage. In some of the earlier works approximate memory has been shown as a potential energy-efficient solution for such error-tolerant applications. In this brief, we propose a single ended 6-T (SE6T) static random access memory (SRAM) cell which has about 50% less dynamic power compared to conventional 6-T SRAM cell with the same bit error rate (BER). Since image processing applications are tolerant to errors, ultra low voltage power-efficient embedded memories with BER can be used for storage. We show that 1 KB ( $256 \times 32$ ) SE6T memory consumes $ {0.45\times }$ dynamic power, $ {0.83\times }$ leakage power and takes $ {0.60\times }$ area as compared to conventional 6T SRAM memory for similar peak signal to noise ratio (PSNR). We have also proposed heterogeneous SE6T 1K SRAM memory and show that for a given power budget, PSNR enhances by at least by 14 dB compared to when homogeneous (identically sized bit-cells) SE6T SRAM memory are used. When compared with heterogeneous 6T SRAM memory, the heterogeneous SE6T SRAM memory consumes $ {0.44\times }$ dynamic power, $ {0.86\times }$ leakage power and takes $ {0.6\times }$ area for almost similar PSNR. For a given PSNR, the SE6T memory is cumulatively better in terms of design complexity, area and power when compared with other hybrid and heterogeneous approximate memories.

PZL-10 Turboshaft Engine–System Design Review

Abstract The PZL – 10-turboshaft gas turbine engine is straight derivative of GTD-10 turboshaft design by OKMB (Omsk Engine Design Bureau). Prototype engine first run take place in 1968. Selected engine is interested platform to modify due gas generator layout 6A+R-2, which is modern. For example axial compressor design from successful Klimov designs TB2-117 (10A-2-2) or TB3-117 (12A-2-2) become obsolete in favour to TB7-117B (5A+R-2-2). In comparison to competitive engines: Klimov TB3-117 (1974 – Mi-14/17/24), General Electric T-700 (1970 – UH60/AH64), Turbomeca Makila (1976 – II225M) the PZL-10 engine design is limited by asymmetric power turbine design layout. This layout is common to early turboshaft design such as Soloview D-25V (Mil-6 power plant). Presented article review base engine configuration (6A+R+2+1). Proposed modifications are divided into different variants in terms of design complexity. Simplest variant is limited to increase turbine inlet temperature (TIT) by safe margin. Advanced configuration replace engine layout to 5A+R+2-2 and increase engine compressor pressure ratio to 9.4:1. Upgraded configuration after modification offers increase of generated power by 28% and SFC reduction by 9% – validated by gas turbine performance model. Design proposal corresponds to a major trend of increasing available power for helicopter engines – Mi-8T to Mi-8MT – 46%, H225M – Makila 1A to 1A2 — 9%), Makila 1A2 to Makila 2-25%.

Function and Regulation of Phase-Separated Biological Condensates.

Achieving functional specificity while minimizing cost to fitness is a key constraint during evolution. Formation of biological condensates by liquid-liquid phase separation (LLPS) appears to serve as an important regulatory mechanism to generate moderate specificity in molecular recognition while maintaining a reasonable cost for fitness in terms of design complexity. Formation of biological condensates serves as a unique mechanism of molecular recognition achieving some level of specificity without a huge cost to fitness. Rapid formation of biological condensates in vivo induced by specific cellular or environmental triggers has been shown to be an important mechanism for increasing cellular fitness. Here we discuss the functions and regulation of biological condensates, especially those formed by LLPS, involving interactions between proteins and nucleic acids. These condensates are spatially isolated within the cytosol or nucleus and can facilitate specific biochemical functions under conditions such as stress. The misregulation of biological condensates resulting in nondynamic aggregates has been implicated in a number of diseases. Understanding the functional importance of biological condensates and their regulation opens doors for development of therapies targeting dysfunctional biological condensates, as well as spatiotemporal engineering of functions in cells.

Reversible Logic-Based Fault-Tolerant Nanocircuits in QCA

Parity-preserving reversible circuits are gaining importance for the development of fault-tolerant systems in nanotechnology. On the other hand, Quantum-dot Cellular Automata (QCA), a potential alternative to CMOS, promises efficient digital design at nanoscale. This work targets design of reversible ALU (arithmetic logic unit) in QCA (Quantum-dot Cellular Automata) framework. The design is based on the fault tolerant reversible adders (FTRA) introduced in this paper. The proposed fault tolerant adder is a parity-preserving gate, and QCA implementation of FTRA achieved 47.38% fault-free output in the presence of all possible single missing/additional cell defects. The proposed designs are verified and evaluated over the existing ALU designs and found to be more efficient in terms of design complexity and quantum cost.

Optimal State Space Control of DC Motor

In comparison to classical cascade control architecture of DC motors, the state feedback control offers advantages in terms of design complexity, hardware realization and adaptivity. This paper presents a methodic approach to state space control of a DC motor. The state space model identified from experimental data provides the basis for a linear quadratic regulator (LQR) design. The state feedback linear control is augmented with a feedforward control for compensation of Coulomb friction. The controller is successfully applied and the closed loop behavior is evaluated on the experimental testbed under various reference signals.