System Design Algorithm Research Articles

Design and operation of an adiabatic compressed air energy storage system incorporating a detailed heat exchanger model

Heat exchangers (HEXs) are among the key components of adiabatic compressed air energy storage (A-CAES) systems. However, the existing HEX models applied in the A-CAES systems are overly simplistic, limiting research regarding design and operational simulation. For the first time, this study incorporates a comprehensive HEX model, including calculations for geometric dimensioning, heat transfer, and pressure drop, into the A-CAES system model; in addition, a novel layered, interactive system design and operational simulation algorithms are developed. The developed models and algorithms can facilitate the design process and yield reasonable operational simulation results with only basic parameters. The design algorithm can determine all key parameters of the system and assess the effect of the HEX pressure drop and heat transfer area on the system performance. The operational simulation algorithm considers the performance of all key equipment under off-design conditions. The design exergy efficiency and daily net income of the system are 73.15 % and $26,998, respectively; however, these values decrease during operation to 72.15 % and $25,034, respectively. A comprehensive analysis of the key parameters during operation revealed that the primary causes for the degradation were the sliding pressure in the energy storage process and variations in the air storage tank parameters.

Enhancing User Experience in E-commerce through Personalization Algorithms A Study on Information System Design

This research aims to improve user experience in e-commerce through the use of personalization algorithms in information system design. The research methods used involve literature analysis, prototype development, and user testing. Literature analysis was conducted to understand the concept of personalization, relevant algorithms, and factors influencing user experience in e-commerce. Based on this understanding, a prototype e-commerce information system with personalization features was implemented. User testing is carried out to collect data about user experiences before and after implementing a personalization algorithm. The research results show that the use of personalization algorithms significantly improves user experience in e-commerce. Users report feeling more engaged, increased relevance of content, and ease in finding products that match their preferences. Apart from that, this research also identifies several important factors that need to be considered in the design of e-commerce information systems that use personalization algorithms, such as data privacy, transparency, and user control. In conclusion, the use of personalization algorithms can effectively improve user experience in e-commerce, with the important note of considering relevant factors.

A Review of the Various Control Algorithms for Trajectory Control of Unmanned Underwater Vehicles

Unmanned underwater vehicles (UUVs) have become increasingly popular in recent years due to their use in various applications. The motivations for using UUVs include the exploration of difficult and dangerous underwater environments, military tasks in mine detection, intelligence gathering and surveillance, the inspection of offshore oil and gas infrastructure in the oil and gas industry, scientific research for studying marine life, and the search and rescue of missing persons or submerged airplanes or boats in underwater environments. UUVs offer many advantages in achieving the desired applications with increased safety, efficiency, and cost-effectiveness. However, there are also several challenges associated with their communication, navigation, power requirements, maintenance, and payload limitations. These types of vehicles are also prone to various disturbances caused by currents of the ocean, propulsion systems, and unmolded uncertainties. Practically, it is a challenging task to design a controller that will ensure optimal performance under these conditions. Therefore, the control system design is of prime importance in the overall development of UUVs. Also, the UUV controller receives input from different sensors, and the data from these sensors are used by the controller to perform different tasks. The control systems of UUVs should take into account all uncertainties and make them stable so that all sensors can perform optimally. This paper presents a complete review of different control system design algorithms for UUVs. The basic logic designs of several control system algorithms are also presented. A comparison is made based on reliability, robustness, precession, and the ability of the controller to handle the nonlinearity that is faced by UUVs during their missions. Simulation and experimental results are thoroughly studied to gain insight into each algorithm. The advantages and disadvantages of each algorithm are also presented, which will facilitate the selection of a suitable algorithm for the control system design of UUVs.

Design and preliminary evaluation of a lower limb exoskeleton based on hydraulic actuator

PurposeThis paper aims to propose a novel system design and control algorithm of lower limb exoskeleton, which provides walking assistance and load sharing for the wearer.Design/methodology/approachIn this paper, the valve-controlled asymmetrical hydraulic cylinder is selected for driving the hip and knee joint of exoskeleton. Pressure shoe is developed that purpose on detecting changes in plantar force, and a fuzzy recognition algorithm using plantar pressure is proposed. Dynamic model of the exoskeleton is established, and the sliding mode control is developed to implement the position tracking of exoskeleton. A series of prototype experiments including benchtop test, full assistance, partial assistance and loaded walking experiments are set up to verify the tracking performance and power-assisted effect of the proposed exoskeleton.FindingsThe control performance of PID control and sliding mode control are compared. The experimental data shows the tracking trajectories and tracking errors of sliding mode control and demonstrate its good robustness to nonlinearities. sEMG of the gastrocnemius muscle tends to be significantly weakened during assisted walking.Originality/valueIn this paper, a structure that the knee joint and hip joint driven by the valve-controlled asymmetrical cylinder is used to provide walking assistance for the wearer. The sliding mode control is proposed to deal with the nonlinearities during joint rotation and fluids. It shows great robustness and frequency adaptability through experiments under different motion frequencies and assistance modes. The design and control method of exoskeleton is a good attempt, which takes positive impacts on the productivity or quality of the life of wearers.

Low-cost and simple optical system based onwavefront coding and deep learning.

With the development of computational imaging, the integration of optical system design and digital algorithms has made more imaging tasks easier to perform. Wavefront coding (WFC) is a typical computational imaging technique that is used to address the constraints of optical aperture and depth of field. In this paper, we demonstrated a low-cost and simple optical system based on WFC and deep learning. We constructed an optimized encoding method for the phase plate under the framework of deep learning, which reduces the requirement for aberration correction in the full field of view. Optical coding was achieved with just a double-bonded lens and a simple cubic phase mask, and digital decoding used the deep residual UNet++ network framework. The final image obtained has good resolution, whereas the depth of field of the system expanded by a factor of 13, which is of great significance for the high-precision inspection and attaching of small parts of machine vision.

Hierarchical Feature Enhancement Algorithm for Multispectral Infrared Images of Dark and Weak Targets

A multispectral infrared zoom optical system design and a single-frame hierarchical guided filtering image enhancement algorithm are proposed to address the technical problems of low contrast, blurred edges, and weak signal strength of single-spectrum infrared imaging of faint targets, which are easily drowned out by noise. The multispectral infrared zoom optical system, based on the theory of complex achromatic and mechanical positive group compensation, can simultaneously acquire multispectral image information for faint targets. The single-frame hierarchical guided filtering image enhancement algorithm, which extracts the background features and detailed features of faint targets in a hierarchical manner and then weights fusion, effectively enhances the target and suppresses the interference of complex background and noise. Solving multi-frame processing increases data storage and real-time challenges. The experimental verification of the optical system design and image enhancement algorithm proposed in this paper separately verified that the experimental enhancement was significant, with the combined use improving Mean Square Error (MSE) by 14.32, Signal-Noise Ratio (SNR) by 11.64, Peak Signal-to-Noise Ratio (PSNR) by 12.78, and Structural Similarity (SSIM) by 14.0% compared to guided filtering. This research lays the theoretical foundation for the research of infrared detection and tracking technology for clusters of faint targets.

The Fiber Bragg Grating (FBG) Sensing Glove: A Review

The fiber Bragg grating (FBG) sensors, which have unique advantages such as small size, biocompatibility, and high sensitivity, have received much attention in hand motion tracking applications. Despite the reported good performance and potential benefits of existing FBG sensing gloves, they still face challenges in terms of glove design, wearability, motion-sensing algorithms, and system accuracy and reliability. This paper aims to provide a comprehensive survey of FBG sensing gloves, focusing on the topics of sensing characteristics, functionality, performance, system design, structure, and motion tracking algorithms. Through this survey, we have identified challenges and research gaps for FBG sensing gloves, including the need for innovation in system and structure design, the development of more advanced models that can better accommodate individual differences, and the improvement of multiplexing sensing capabilities. This survey can serve as a guide for future research in this exciting field.

Image Quality Assessment for Digital Volume Correlation-Based Optical Coherence Elastography

Optical coherence elastography (OCE) based on digital volume correlation (DVC) has the advantages of full 3D displacements and strain tensor quantification. However, the measurement results are often unreliable due to the poor quality of the optical coherence tomography (OCT) speckle patterns. This paper proposes an image evaluation index based on OCT-DVC (CMGG, combined mean attenuation intensity, breadth and dispersion of the gray level distribution), which comprehensively considers the OCT signals’ attenuation and the breadth and dispersion of the gray level distribution of the OCT images. Virtual deformation experiments of phantoms by numerically applied displacements and deformation measurement of pork meat were conducted. The results of the mean bias errors have a corresponding good relationship with CMGG, which demonstrates the effectiveness of the proposed CMGG. Based on this index, a lot of time may be saved by a pretest evaluation during DVC-OCE measurement. CMGG also guides the development of OCE system design, adjustment and new DVC-OCE algorithms.

An online auction-based incentive mechanism for soft-deadline tasks in Collaborative Edge Computing

Recently, Collaborative Edge Computing (CEC) has been proposed as an effective method to improve the performance of Mobile Edge Computing (MEC) systems by offloading workload from busy MEC servers to idle ones. Although extensive research has been conducted to study the system design and scheduling algorithms in CEC, the incentive mechanism between end-users and collaborative servers yet receives much less attention. To fill the gap, in this paper, we propose an online auction-based incentive mechanism where the task requests arrive stochastically and MEC servers need to decide whether to accept them without future information. To guarantee the applicability of our mechanism, we consider a comprehensive model where both the valuation of tasks and operation costs of edge servers are represented by general functions. Through theoretical analysis, we formally proved our mechanism achieves desirable properties, such as truthfulness and polynomial time complexity. Based on the primal–dual optimization framework, we further demonstrate the competitive ratio of our mechanism with respect to the optimal offline social welfare. Extensive simulations are conducted to verify our theoretical analysis and validate the effectiveness of our mechanism.

Optimization of System Design and Calibration Algorithm for SPAD-Based LiDAR Imager

This paper presents the optimization of system design and calibration algorithm for LiDAR imager based on the single-photon avalanche diode (SPAD) image sensor. The supply voltage and the gating high-voltage driving circuit of the SPAD is optimized based on theoretical analysis and experimental data to improve the trigger times of the SPAD for the laser echo. The real-time calibration algorithm is realized in field programmable gate array (FPGA) to obtain the flight time and improve measurement reliability. A 10-bit time-efficient and area-efficient shifted inter-frame multi-event histogram and bubbling-based peak detection algorithm are used to calculate flight time, which requires the memory as low as 16 times smaller than storing complete histogram if the pixel values are coded on up to 10 bits and can detect up to four different targets simultaneously without increasing the measurement time. The performance of different kinds of background noise measurement methods is analysis based on experimental data, which shows that the measurement results are more accurate with the increasing of TDC event detection ability. The proposed crosstalk suppression algorithm based on LiDAR transmission function can reduce optical crosstalk between adjacent pixels to improve the measurement reliability of the LiDAR imager. The LiDAR imager is presented capable of measuring 10 m range with 70 Klux background noise and 30°×45° field of view.

System Design and SVM Identification Algorithm for the Ultrasonically Catalyzed Single-Sensor E-Nose

In this article, a system design method and Support Vector Machine (SVM) gas identification algorithm for the ultrasonically catalyzed single-sensor E-nose is proposed and investigated for the first time. In the aspect of hardware, the E-nose system consists of an ultrasonic module, sensing module, data processing module, personal computer, and power supply module. In the aspect of software, a microcontroller in the data processing module is coded by C programming language for data acquisition and operational control, and a user interface is made on the PC by C# programming language for display and sending commands. Performance of the integrated E-nose is tested and evaluated by methanol, ethanol, acetone, and hydrogen gases, respectively. The experimental results show that the integrated E-nose can achieve up to 100% gas identification success rate in the concentration range greater than 10% LEL (LEL = lower explosive limit), with a concentration measurement error less than 10%, and the SVM algorithm can effectively improve the gas identification ability in the low-concentration range (1%–10% LEL). For 1% LEL methanol target gas, it raises the gas identification success rate from 0% to 90%.

Intelligent Reflecting Surface-Aided Indoor Visible Light Communication Systems

This letter explores the use of intelligent reflecting surfaces (IRSs) to address the line-of-sight (LoS) blockage issue in an indoor visible light communication (VLC) system. This is done while considering practical user behaviors such as random receiver orientation and the presence of obstructions in the direct link between the transmitter and the receiver. Specifically, a system model for an IRS-aided VLC system is proposed and a rate maximization problem is considered to determine the optimal orientation of the IRS mirror array to establish robust non-LoS links. A low-complexity iterative solution based on the sine-cosine algorithm is proposed for this non-convex optimization problem. Simulation results are used to verify the effectiveness of the proposed IRS-aided VLC system design and optimization algorithm in overcoming the LoS blockage issue.

A Novel Fast Multiple-Scattering Approximate Model for Oceanographic Lidar

An effective lidar simulator is vital for its system design and processing algorithms. However, laser transmission is a complex process due to the effects of sea surface and various interactions in seawater such as absorption, scattering, and so on. It is sophisticated and difficult for multiple scattering to accurately simulate. In this study, a multiple-scattering lidar model based on multiple-forward-scattering-single-backscattering approximation for oceanic lidar was proposed. Compared with previous analytic models, this model can work without assuming a homogeneous water and fixed scattering phase function. Besides, it takes consideration of lidar system and environmental parameters including receiver field of view, different scattering phase functions, particulate sizes, stratified water, and rough sea surface. One should note that because the scattering phase function is difficult to determine accurately, the simulation accuracy may be reduced in a complex oceanic environment. The Cox–Munk model used in our method simulates capillarity waves but ignores gravity waves, and the pulse stretching is not included. The wide-angle scattering occurs in the dense subsurface phytoplankton, which sometimes makes it hard to use this model. In this study, we firstly derived this method based on an analytical solution by convolving Gaussians of the forward-scattering contribution of layer dr and the energy density at R in the small-angle-scattering approximation. Then, the effects of multiple scattering and water optical properties were analyzed using the model. Meanwhile, the validation with Monte Carlo model was implemented. Their coefficient of determination is beyond 0.9, the RMSE is within 0.02, the MAD is within 0.02, and the MAPD is within 8%, which indicates that our model is efficient for oceanographic lidar simulation. Finally, we studied the effects of FOV, SPF, rough sea surface, stratified water, and particle size. These results can provide reference for the design of the oceanic lidar system and contribute to the processing of lidar echo signals.

Suboptimal control for nonlinear slow‐fast coupled systems using reinforcement learning and Takagi–Sugeno fuzzy methods

SummaryIn this article, by using singular perturbation theory, reinforcement learning (RL), and Takagi–Sugeno (T‐S) fuzzy methods, a RL‐fuzzy‐based composite suboptimal control method is proposed for nonlinear slow‐fast coupled systems (SFCSs) with unknown slow dynamics. First, the SFCSs is decomposed into slow and fast subsystems and the original optimal control problem is reduced to two subproblems. Then, for the slow subsystem, a nonlinear coordinate transformation is introduced to transform the nonquadratic slow utility function into the quadratic form. Unmeasurable virtual slow subsystem state is reconstructed by the state measurements of original system and slow controller design algorithm is proposed in the framework of RL by utilizing the actor‐critic neural networks to approximate the controller and cost function. For the fast subsystem, T‐S fuzzy model is established and state measurements of the original system are exploited to reconstruct the unmeasurable fast subsystem state. Fast controller is designed with the approach of parallel distributed compensation. The obtained slow and fast controllers form the composite suboptimal controller for the original SFCSs. Considering the state reconstruction error, convergence of the slow controller design algorithm, suboptimality of the composite controller, and stability of the closed‐loop SFCSs are analyzed. Finally, the effectiveness of our proposed method is illustrated by examples.

A two‐dimensional quasi‐optical system design method with low cross‐polarization based on Gaussian beam mode analysis

AbstractIn the design of quasi‐optical systems, the cross‐polarization introduced by off‐axis mirrors is a major concern to us. By Gaussian beam mode analysis (GBMA), the electric field could be predicted precisely with this factor. In this study, we present some significant expressions and a method based on the energy of modes to analyze the influence of design parameters such as the distance between two objects and the incident angles of beams on the cross‐polarization level of a two‐dimensional (2D) multi‐reflector system with a feed containing cross‐polarization. Finally, combining these discussions, an innovative 2D quasi‐optical system design algorithm with low cross‐polarization based on the particle swarm optimization (PSO) algorithm is proposed considering various system variables. In order to verify the validity and accuracy of our method, we compare the results of our approach and physical optics (PO) in the commercial software package GRASP10 with the example of a double ellipsoidal mirror system.

A Gesture Air-Writing Tracking Method that Uses 24 GHz SIMO Radar SoC

Gesture air-writing is an advanced nontouching interaction method that replaces traditional typewriter keyboards, touch screens and other input devices. Due to its low power consumption, noncontact detection and independence from light conditions, millimeter wave radar has become a valuable gesture air-writing solution. In this paper, we proposed a prototype of a gesture air-writing tracking system that is based on the 24-GHz frequency-modulated continuous-wave (FMCW) radar system-on-chip (SoC). The transmitted chirp signal of this radar chip covers up to a 4-GHz bandwidth, which provides sufficient range resolution to track hand gestures. With the development of single input, multiple output (SIMO) antennas, the air-writing symbols can be reconstructed in an observation plane. A system design and signal processing algorithm for gesture air-writing applications is proposed for the prototype system in this paper. To test the performance of the proposed method, experiments with cases of five simple gestures, air-writing numbers and letter tracking are carried out. The experimental results verify the efficiency and accuracy of the proposed method.

ФЕНОМЕНОЛОГІЯ ПРОЕКТУВАННЯ НОВІТНІХ ОСВІТНІХ СИСТЕМ У ГЛОБАЛЬНОМУ ОСВІТНЬОМУ СЕРЕДОВИЩІ

Introduction. It is taken as a benchmark that every person is interested in the fact that not only the widest possible reveal his dignity and potential opportunities, not only to receive education, but also the ability to adapt to the new political and socio-economic realities of the present. The state, however, should take care of the satisfaction of these needs of the individual, which would be combined with the examination of the needs of the community as a whole. To do this, it is necessary to rely on the theoretical model of the "innovative person", which is tested in the world and focused on instilling proficiency, solid knowledge, flexibility and mobility into high school graduates.Purpose. The purpose of the article is the theoretical substantiation of the algorithm of system design of the model of the modern educational system, which reveals the essence and features of the global educational environment.Methods. The system of general scientific and special methods of theoretical (analysis of scientific literature on the studied problem, systematization, generalization of materials, content analysis) and empirical research (monitoring of military specialists, use of diagnostic tools, etc.). Results. On the basis of the analysis of domestic and foreign practice in the design of educational systems, we generalized the procedural programming of the JC system of higher education, which is a complex and objective procedure, through which a unified information, pedagogical and methodological basis ensures the unity of requirements to the content and quality of training of specialists, regardless of departmental subordination institutions of higher education and forms of ownership.Originality. The organizational framework for ensuring the processes of designing and forecasting of perspective educational systems, the quality of design decisions is a logical scheme of interaction of decision-making levels. They can be submitted using the following system analysis formula: object as target category - process as a category of means to achieve the goal - system that implements the process.Conclusion. The priority of the directions of the state policy in the context of the integration of the national higher education into the European and world educational space is that the necessary prerequisite for the design of an innovative model of higher education is the coherent renewal of the educational system, in particular, the improvement of its staffing, which to a large extent depends on the ability of the education system to train highly skilled professionals.

Optical Navigation Preparations for the New Horizons Kuiper-Belt Extended Mission

Acquiring and processing astrometric measurements of a spacecraft’s target using on-board images, generically referred to as optical navigation, is an integral function of the orbit determination and navigation of NASA’s New Horizons spacecraft. Since New Horizons’ reconnaissance of the Pluto system in July 2015, many preparations have been completed to further enhance the optical navigation system and prepare for the reconnaissance of New Horizons’ next target, Kuiper Belt Object (486958) 2014 MU69 (unofficially nicknamed Ultima Thule). Due to its low relative brightness compared to most planetary exploration targets, Ultima Thule presents several unique challenges to the optical navigation system. The optical navigation system design, imaging schedule, and technical algorithms that were developed and tailored to these challenges are explored in detail. Additionally, several operational readiness tests, simulation methods, and test results are presented and analyzed to assess the optical navigation system performance and implications to flight operations. Lastly, a first look at Ultima as viewed from the New Horizons LORRI imager is presented.

3D-printable portable open-source platform for low-cost lens-less holographic cellular imaging

Digital holographic microscopy is an emerging, potentially low-cost alternative to conventional light microscopy for micro-object imaging on earth, underwater and in space. Immediate access to micron-scale objects however requires a well-balanced system design and sophisticated reconstruction algorithms, that are commercially available, however not accessible cost-efficiently. Here, we present an open-source implementation of a lens-less digital inline holographic microscope platform, based on off-the-shelf optical, electronic and mechanical components, costing less than $190. It employs a Blu-Ray semiconductor-laser-pickup or a light-emitting-diode, a pinhole, a 3D-printed housing consisting of 3 parts and a single-board portable computer and camera with an open-source implementation of the Fresnel-Kirchhoff routine. We demonstrate 1.55 μm spatial resolution by laser-pickup and 3.91 μm by the light-emitting-diode source. The housing and mechanical components are 3D printed. Both printer and reconstruction software source codes are open. The light-weight microscope allows to image label-free micro-spheres of 6.5 μm diameter, human red-blood-cells of about 8 μm diameter as well as fast-growing plant Nicotiana-tabacum-BY-2 suspension cells with 50 μm sizes. The imaging capability is validated by imaging-contrast quantification involving a standardized test target. The presented 3D-printable portable open-source platform represents a fully-open design, low-cost modular and versatile imaging-solution for use in high- and low-resource areas of the world.

Space‐variant analysis and target echo simulation of geosynchronous SAR

The geosynchronous synthetic aperture radar (GEO SAR) echo simulation has an important significance for GEO SAR system design and image algorithm verification. The study discusses the main steps of the GEO SAR echo simulation process and the calculation of key parameters. At the same time, because GEO SAR has a high orbital altitude and a long-time delay, the error caused by the ‘go-stop-go’ hypothesis must be taken into account. For this reason, the authors have studied the slant range iterative model without the assumption. It is used to calculate the distance between the satellite and target in the echo simulation. Experimental results show that the method is effective and feasible. Based on this, the space variant characteristics of GEO SAR are analysed in detail. It can be seen that the echo signals do not satisfy the range and azimuth invariance.