Tool Box Research Articles

Hybrid IGA-FEA of fiber reinforced thermoplastic composites for forward design of AI-enabled 4D printing

Fused deposition modeling (FDM)-based 4D printing uses thermoplastics to produce artifacts and requires computational analysis to assist its design processes of complex geometries. Previously, finite element analysis (FEA) has been used to simulate 4D printing deformations, and its accuracy has been computationally and experimentally verified. However, using FEA also leads to several limitations, such as geometric approximation error and the computational time-cost due to the high degrees of freedom. To address these issues, this paper introduces isogeometric analysis (IGA) into the deformation simulations and propounds a composite design by hybridizing FEA and IGA elements to reduce the number of degrees of freedom while maintaining the simulation accuracy. Moreover, since the hybrid IGA-FEA method used for modeling 4D printing structure deformation excludes real-time interactivity, we develop a polycube-based random forest regressor machine learning (ML) model to learn the IGA-FEA-based structural mechanics simulations and provide fast deformation predictions. Given the input actuator block distribution and geometry configurations, our well-trained model can predict the residual stress-induced deformation behaviors of mesh-like thermoplastic composite structures. With an error less than 0.11% and computation speed 20 times faster than hybrid IGA-FEA simulations, our model can create real-time (0.93 s) and truthful (99.89% accuracy) results. The effectiveness of the proposed model is demonstrated with several complex design examples. We believe the presented workflow effectively combines IGA, FEA, ML, and 4D printing to provide a powerful computational tool that enriches the 4D printing design tool box, and brings huge application potentials.

CRISPR/Cas-based Human T cell Engineering: Basic Research and Clinical Application

Engineering human T cells for the treatment of cancer, viral infections and autoimmunity has been a long-standing dream of many immunologists and hematologists. Although primary human T cells have been genetically engineered for decades, this process was challenging, time consuming and mostly limited to transgene insertions mediated by viral transduction. The absence of widely accessible tools to efficiently and precisely engineer T cells genetically in a targeted manner limited their applicability as a living drug. This fundamentally changed with the discovery of CRISPR/Cas9 and its adaptation to human T cells. CRISPR/Cas9 has made T cell engineering widely accessible and accelerated the development of engineered adoptive T cell therapies. Only 6 years after the discovery of CRISPR/Cas9 as a biotechnological tool the first CRISPR engineered T cells have been administered to patients with refractory cancers in a phase I clinical trial. Novel Cas proteins - natural and engineered ones - are rapidly emerging. These offer for instance increased flexibility, activity and/or specificity. Moreover, sophisticated protein engineering and fusions of Cas with deaminases or reverse transcriptases enable genomic DNA editing without the need for a double strand cut. Thus, the “CRISPR tool box” for experimental use as well as for novel therapeutic approaches is rapidly expanding. In this review, we will summarize the current state of CRISPR/Cas-based engineering in human T cells for basic research and its clinical applications.

“Counting drops and observing color”: Teachers’ and students’ first experiences in small-scale chemistry practicum of acid-base solutions

This research introduced small-scale chemistry practicum techniques on the concept of acid-base identification, determination of pH with indicators, and neutralization reactions with the concept of titration. This research aims to reveal teachers’ and students’ first experiences in small-scale chemistry practicum. This research is action research to introduce a small-scale practicum technique for the solution of minimizing chemical tools and materials, as well as the availability of space for school chemistry practicum. This study involved 26 teacher participants and 36 student participants. The data collected in the form of quantitative data related to teacher responses to small-scale chemistry practicum workshops and student responses to small-scale chemistry practicum in the pilot class. The instrument used is an activity response questionnaire. Qualitative data is collected through observation, interviews, and documentation. The practicum involves qualitative observations and quantitative calculations. The qualitative aspect relates to the observation of color changes that occur in the mixture of solutions made from acid and alkaline solutions with a certain composition. Teachers got a lot of inspiration in terms of practicing chemistry with fewer material requirements, as well as modifying the tools used for laboratory activities. The tool and material box package illustrated to them that practicum activities do not have to be carried out in a laboratory room, but can also be practiced in conventional classrooms, even done independently by students at home. Students have a unique experience in the process of counting the number of droplets because it requires concentration and careful observation.

Reconstituting teachers’ professional knowledge: using Cultural Studies to rethink multicultural education

ABSTRACT This article examines the utility of drawing on Cultural Studies to aid teachers in reassessing understandings and approaches to multicultural education; how engaging with notions of cultural complexity, hybridity and essentialism offers a critical tool box around issues of cultural difference that ultimately provides a better understanding of school communities in a global context. We revisit teachers involved in the Rethinking Multiculturalism, Reassessing Multicultural Education project from a decade ago who, at the time, expressed the greatest sense of impact of the professional learning they received in the project. We asked these teachers to reflect on that experience, and whether the theory employed in the training continued to influence their teaching practice. This is contrasted with current, more instrumentalised, approaches to teacher professional learning raising questions about the nature of professional knowledge, the relationship between theory and practice and the broader utility of Cultural Studies in education.

A modified direct inverse Prandtl–Ishlinskii model based on two sets of operators for the piezoelectric actuator hysteresis compensation

Piezoelectric actuator (PEA) is widely applied in the field of micro/nano high precision positioning. However PEA has the phenomenon of hysteresis non-linearity between input voltage and output displacement, due to the natural property of piezoelectric materials. The PEA hysteresis can be compensated by hysteresis models, which makes the input voltage and output displacement more linearity. The research work on compensation of PEA hysteresis by using various hysteresis models has been being a hot topic. This paper presents a modified direct inverse rate-independent Prandtl–Ishlinskii (PI) (MDIPI) model for compensating the hysteresis of PEA. The proposed MDIPI model has two different sets of operators compared with classical PI (CPI) model having one set of operators. For the two sets operators in MDIPI model one is rate operators and the other is modified classical operators. By combining the two sets operators, the MDIPI model has the properties of the adaption and accuracy in hysteresis compensation. The MDIPI model can be used as feedforward controller to compensate different reference trajectories. Parameters of MDIPI model are calculated by matlab optimization tool box. The experiments of compensating the complex displacement trajectory and sinusoidal trajectory are validated on a platform of commercial PEA. The MDIPI model has achieved more accurate results than the Krasnosel’skii–Pokrovkii (KP), Preisach and CPI models. It is effective in improving the accuracy of PEA hysteresis compensation.

Power quality improvement using ultra capacitor based dynamic voltage restorer with real twisting sliding mode control

Introduction. Power quality is a major problem in today's power system, since it may have an impact on customers and utilities. Problem. Power quality is important issue of financial consequences for utilities, their consumers and load apparatus vendors. Voltage sag/swell are the most significant and usually occurring power quality issues in a secondary distribution system for sensitive loads. Goal. Dynamic voltage restorer is a fast, flexible, effective and dynamic custom power device can be used to compensate voltage sag/swell with integration of energy storage. Ultra capacitors have ideal properties of great power density and low energy density for elimination of voltage sag/swell. Their performance is mostly determined by the control strategy established for switching of voltage source converters. Originality. In this research, a strategy for the voltage source converter of dynamic voltage restorer based on the real twisting sliding mode control and ultra capacitor is developed to correct the fault that successfully eliminates the impacts of voltage sag/swell. Methodology. Ultra capacitor along with real twisting sliding mode control gives the more robustness and faster response, with also increasing the compensation time of the dynamic voltage restorer. Testing environment. To evaluate the performance of the proposed control approach, the MATLAB / Simulink SimPower System tool box is employed. Practical values. According to Simulation results clearly shows that the ultra capacitor along with real twisting sliding mode control effectively eliminate the voltage sag/swell in a very short time of 2 ms as compared to IEEE standards that is 20 ms, with less than 5 % total harmonic distortion for sensitive loads as per Information Technology Industry Council Curve and SEMI-F-47 Standards.

Age-related changes and longitudinal stability of individual differences in ABCD Neurocognition measures

Temporal stability of individual differences is an important prerequisite for accurate tracking of prospective relationships between neurocognition and real-world behavioral outcomes such as substance abuse and psychopathology. Here we report age-related changes and longitudinal test-retest stability (TRS) for the Neurocognition battery of the Adolescent Brain and Cognitive Development (ABCD) study, which included the NIH Toolbox (TB) Cognitive Domain and additional memory and visuospatial processing tests administered at baseline (ages 9–11) and two-year follow-up. As expected, performance improved significantly with age, but the effect size varied broadly, with Pattern Comparison and the Crystallized Cognition Composite showing the largest age-related gain (Cohen’s d:.99 and.97, respectively). TRS ranged from fair (Flanker test: r = 0.44) to excellent (Crystallized Cognition Composite: r = 0.82). A comparison of longitudinal changes and cross-sectional age-related differences within baseline and follow-up assessments suggested that, for some measures, longitudinal changes may be confounded by practice effects and differences in task stimuli or procedure between baseline and follow-up. In conclusion, a subset of measures showed good stability of individual differences despite significant age-related changes, warranting their use as prospective predictors. However, caution is needed in the interpretation of observed longitudinal changes as indicators of neurocognitive development.

An efficient workflow for meshing large scale discrete fracture networks for solving subsurface flow problems

A large percentage of subsurface hydrocarbon reservoirs are characterized as very complex due to presence of small to large scale fractures. Modeling of multi-physics processes like, environmental flow, CO2 sequestration, hydrocarbon flows, and so on, through such geologically complex reservoirs is challenging. Main challenges comes from the large scale variation in the fracture scales. Use of traditional modeling approaches, based on dual-porosity/dual permeability medium, to model such complex systems is complicated and results in incorrect flow patterns. Precise and efficient modeling of the fracture networks requires fractures to be represented as lower dimensional objects, which requires an efficient gridding technique. In last decade alone modeling of flow through discrete fracture systems has attracted attention from a number of researchers. As a result few new gridding and discretization techniques have been proposed to model flow through discrete fracture network systems (DFNs). DFN’s usually involve very high or very low angle fracture-fracture intersections and sometime presence of small to very large length scale fracture networks. In this article an efficient workflow for meshing of large scale complex DFN’s networks as lower dimensional objects is presented supported by quantitative results with aim of developing a software tool box, which could be coupled to a subsurface multi-phase flow simulator.

An insight into multifunctional tool box: Akkermansia muciniphila provides dynamic benefits to the human gut

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Financial Sector Supervision in Digital Age: Transformation in Progress

Abstract The paper aims at the identification and analysis of major issues facing financial sector supervision resulting from the digitalization of financial markets and the digitalization of supervisory architecture with the tool box applied. It is based on the desk research using foremostly industrial studies which provide necessary information on the current international accomplishments and plans. The paper indicates a growing application of new supervisory tool box and digital-based suptech instruments. It is reinforced by increased digitalization of supervisory analytics, application of big data, and artificial intelligence. Digitalization involves additionally changing relationships between supervisors and supervised entities. The findings of the paper allow for better understanding of the necessary adaptive actions to be taken by both supervisors and supervised entities. The issues raised by the paper are poorly documented by current research and may constitute a contribution to further research in the area.

Evaluation of Vascular Cognitive Impairment Using the ICMR-Neuro Cognitive Tool Box (ICMR-NCTB) in a Stroke Cohort from India.

Vascular cognitive impairment (VCI) presents with a spectrum of cognitive impairment due to stroke and poses a huge socioeconomic burden especially in low middle-income countries. There is a critical need for early recognition and identification of VCI patients. Therefore, we developed and validated culturally appropriate neuropsychological instruments, the ICMR-Neuro Cognitive Tool-Box (ICMR-NCTB) and Montreal Cognitive Assessment (MoCA) to diagnose vascular MCI and dementia in the Indian context. A total of 181 participants: 59 normal cognition, 25 stroke with normal cognition, 46 vascular MCI (VaMCI) and 51 vascular dementia (VaD) were recruited for the study. The ICMR-NCTB and MoCA were administered to patients with VCI and major cognitive domains were evaluated. The ICMR-NCTB was found to have good internal reliability in VaMCI and VaD. The sensitivity of the ICMR-NCTB to detect VaMCI and VaD ranged from 70.8% to 72.9% and 75.9% to 79.7%, respectively, and the specificity for VaMCI and VaD ranged from 84.8% to 86.1% and 82.5% to 85.2%, respectively. The MoCA had excellent sensitivity and specificity to detect VaMCI and VaD at ideal cut-off scores. The ICMR-NCTB is a valid neuropsychological toolbox that can be used for comprehensive cognitive assessment and diagnosis of VCI in India. In addition, the Indian version of MoCA is more adept as a screening instrument to detect VCI due to its high sensitivity. The ICMR-NCTB will aid in early detection and management of many patients, thereby reducing the burden of vascular MCI and dementia in India.

Investigation of the relationship between Ironworker’s gait stability and different types of load carrying using wearable sensors

Load carrying can cause changes in gait stability. Maintaining gait stability (body balance) on a steel frame is an important factor in the prevention of accidents. However, the effects of load carrying on a restricted surface (width), where ironworkers usually perform their jobs, have rarely been investigated. In this context, this study investigates the effect of different types of load-carrying scenarios on the gait stability of ironworkers. Accordingly, to identify the relationships between the weight of load, type of load-carrying method, type of load-carrying tools, and gait stability, represented as the dynamic time warping (DTW) values, an experiment was conducted under 15 different load-carrying conditions. The change in DTW according to the different load conditions was as follows: For one-handed load-carrying using a toolbox, the average DTW values were 23.31 at a weight of 3 kg, 23.80 at 6 kg, 33.20 at 10 kg, 65.84 at 16 kg, and 103.50 at 20 kg. Moreover, for one-handed load-carrying using a bucket, the average DTW values were 23.07 at 3 kg, 24.76 at 6 kg, 34.35 at 10 kg, 77.52 at 16 kg, and 108.28 at 20 kg. Finally, in the case of both-handed load carrying, the average DTW values were 24.31 at 6 kg, 28.11 at 10 kg, 27.23 at 16 kg, 37.90 at 20 kg, and 40.96 at 32 kg. As the weight of the load increased, the DTW values in almost all the experimental cases also increased. Furthermore, the DTW values for bucket carrying and tool box carrying showed clear differences above a certain weight (16 kg). Thus, the results of the experiments indicate that different types of load-carrying conditions significantly affect the ironworkers’ gait stability as they walk on a steel frame. Finally, the calculated DTW values were compared with the subjective perceived ratings to validate the experimental results. The DTW value was highly correlated with the subjective perceived rating scores (Pearson coefficient: 0.929). The results of this study will facilitate the use of gait stability measurements to enhance the construction safety of ironworkers.

Design and Simulation of an Inverter Drive System with a Display for a Renewable Energy System in the Rural Isolated Communities of Uganda

In medical diagnostics, therapeutic, laboratory, intensive care unit devices, and machines application, two form of Electrical Energy is utilized. Alternatives current (AC) and Direct current (DC) form. In this paper an inverter driver system with a display model is made using MATLAB and its specific tool box of Simulink, the process will involve converting single phase alternating current power to direct current using rectifier made from ordinary normal diodes then converted to three phase using three-arm insulated gate bipolar transistors this is commonly known as inverter bridge which is sufficient enough to run three phase loads depending on the application requirement. The system uses a five-level inverter with low levels of distortions and ripples in the equipment output, this increase and improves the performance of the system. Using carefully selected passive and active elements such as capacitor resistors, inductors, diodes, and transistor system in inverter, decreases the number of switches and boosts the efficiency of the system. This inverter drive system helps us to run three phase machines in the health facility at the same frequency of single phase. The inverter system allows a smaller smoothing capacitor in the DC-AC link as proposed. Large smoothing capacitors are conventionally essential in such converters to absorb power ripple at twice the frequency of the power supply. The proposed network topology consists of an indirect matrix converter and an active snubber to absorb the power ripple, and does not necessitate a reactor or large smoothing capacitor. Simulation result is shown using MATLAB software and used to verify system operation principle as well as circuit development and their control mechanism for a single-to-three-phase power inverter system. The results from experiment show that for a 1 kW-class prototype circuit system, the power ripple at twice the frequency of the power supply can be adequately suppressed using a buffer capacitor of low values.

Fast Speed Convergent Stability of T-S Fuzzy Sliding-Mode Control and Disturbance Observer for a Secure Communication of Chaos-Based System

This article presents the fast convergent stability of disturbance observer (DO) and sliding mode control (SMC) for a secure communication of fractional-order chaotic-based system. First, the fractional-order is remodeled into a Takagi-Sugeno fuzzy (TSF) system with the aim of softening the calculations of observer and controller design. Second, the master and slave systems (MSSs) were synchronized by the fast convergent stability (FCS) sliding mode control with double phases of the same stability condition. Third, the disturbance observer was newly proposed for estimating the disturbance and uncertainty of the secure communication system (SCS). Fourth, the stability of the proposed method was archived via the Lyapunov condition. The MATLAB simulation with support of FOMCON tool box was used to validate the correction of the proposed control theory. The obtained results such as small tracking errors and small settling-times were used to confirm that the proposed theory is good at rejecting perturbations and used control method is good at synchronizing the chaotic systems.

Untangling Pancard By Designing Optical Character Reader Tool Box By Correlating Alpha Numeric Character

Diabetic foot ulcer is one of the major complication in Diabetes mellitus. The infective diabetic toe ulcer was mainly caused due to the trauma affecting the surrounding tissue of the toe . the area of the right little toe of the dorsal region was affected by the microbial infection in an uncontrolled situation . In this case the possible study efforts were made to prevent the diabetic foot ulcer of a patient which was mainly due to the trauma. The diabetic foot ulcer with tissue exposure and microbial infection on the dorsal surface of the little toe was mainly due to the trauma .The right lower limb of little toe was amputated due to uncontrolled type -2 diabete mellitus which is associated with infection. To control microbial infection associated with traumatic ulcers split skin grafting was done to reduce the infection and promoting re-epithealisation. For fast healing of the wound Antibiotics like Beta-lactum antibiotics, Cephalosporins and Fluroquinolones was suggested.

Influence of machining parameters on surface roughness in AL6063-W composite by wire EDM process: Experimental investigations and process optimization

Surface roughness in a machining process plays a vital role in the dimensional accuracy of the machine part. In view of this, in the present work experimental investigations were performed on a novel AL6063-W alloy by a commercial wire electric discharge machine in order to study the influence of machining parameters on the surface roughness of the material. Pulse on time (Ton), servo voltage (Sv), and pulse off time (Toff) were chosen as the machining parameters. Stir casting method was used for the development of the composite. In order to predict the surface roughness the model was developed using the response surface methodology (RSM) technique. Central composite design (CCD) was used to design a 20 set experiments, and the developed model was validated using the random set of parameters. The statistical model was developed using the analysis of variance (ANOVA) technique at a confidence interval of 95% i.e. p=0.05. It was obtained that among the chosen factors, TonandToff played the significant influence on the surface roughness of the composite. Further, genetic algorithm tool box using MATLAB was used to determine the optimum parameters for minimum surface roughness.

Performance evaluation of different configurations of system with DSTATCOM using proposed Icos⁡ϕ technique

The proposed Icos⁡ϕ control technique has been applied for power quality improvement using different configurations of system with distribution static compensator (DSTATCOM). Modeling, design and control of DSTATCOM are analysed in detial. Three phase reference current are extracted with this technique. The proposed technique has been used for power factor enhancement, voltage regulation, harmonic suppression and load balancing under dynamic condition with non-linear load. The proposed control is very effective for three different configurations of system with DSTATCOM for power quality improvement. Results for each configuration of system with DSTATCOM are simulated using MATLAB/Simulink sim power tool box. For teaching the power quality course, these can also be helpful.

Radar Cross Section Modelling and Analysis of Static and Dynamic Targets using MATLAB

Radar Cross Section (RCS) is an important characteristic of the electromagnetic system for target detection. This study presents detailed modelling of Radar Cross Section (RCS) of static simple objects like sphere, cylinder, triangular plate, circular flat plate, truncated cone and complex objects using MATLAB Radar toolbox. The RCS modelling of simple objects is also done with MATLAB POFACET GUI 4.3 and the results are compared with MATLAB Radar tool box. The RCS of complex objects are vectorially added in MATLAB and modelled in this work. Modelling includes 1. A cylinder with a circular flat plate on both ends 2. A circular cylinder with ellipsoid at front end 3. A truncated cone (frustum) with circular plates at both ends 4. The half ellipsoid with a frustum and the flat plate. The simulation and comparison of the RCS variations in dBsm with respect to aspect angle for parameters such as size and frequency of the simple and complex objects have been carried out in this work. RCS of a complex object with dynamic characteristics is also analysed using the Chi-square probability density function. ’The scope of this paper is limited to the objects with deterministic shapes and the combined objects using those shapes. The detailed experimental study on the sphere shows that RCS remains the constant in all directions for sphere. The study also highlights the RCS return is maximum at 180 degrees when the cylinder is aligned horizontally with the RADAR and minimum RCS is obtained at 90 degrees and 270 degrees. In the case of ellipsoid, the RCS is maximum at 90 degrees and 270 degree and minimum at 180 degrees. For the triangular flat plate, the RCS is maximum at 0 degree and 180 degrees and minimum at 90 degrees. For the truncated cone the RCS has maximum and minimum values at aspect angles of zero degrees and 80 degrees. The model of the frustrum with flat plate at both ends provides maximum RCS due to the frustrum and minimum due to flat plate and the normal incidence occurs at 73.3008 degrees. The Swerling models for the fluctuating RCS are also analysed in detail which will be used to measure RCS of high-speed debris revolving around the earth's surface by the radar in Low Earth Orbit (LEO).

The Application of An Intelligent Adaptive Controller for Permanent Magnet Synchronous Motor Drive Using Neural Network

Electrical motors are designed to operate with high performance and precision while a fast response is achieved by the intended control. Compared to traditional synchronous motors, permanent magnet synchronous motors have complicated mathematical and non-liner models when considering control design. Designing traditional control system becomes more difficult especially when dealing with the interactive parameters. Moreover, the neural network control systems have been a topic of interest since they can be implemented for non-liner and complicated systems without considering the mathematical model of the proposed system. In order to obtain a desired response, the design is achieved through procedure called training the network based on the model. Therefore, this paper presents an implementation of a neural network for a permanent magnet synchronous motors control where improvement of the performance of control is achieved and compared with conventional proportional-integral control. The Matlab/Simulink tool box is used to simulate the proposed system. Simulation results have shown that the suggested controller provides better response than traditional proportional-integral controller for the speed control for synchronous motor driver. In addition, the speed/torque of the selected permanent magnet synchronous motor can be controlled as a desired

Real-time Optimization and Implementation of Multi-rate Digital FIR Kernel Filter

One ideal performance of this design is in the areas of decimation where a decimation factor of 10, 45-order and pass band ripple of 1dB and interpolation of sampled rates where a sinusoidal signal input produced a ripple free output with interpolation factor of 10, 52-order and stopband attenuation of 60dB. Owing to the multiple samples of filter length of 200, the filter performed down sampling preceded with filtering as well as up sampling preceded with filtering, hence multi-rate filter by allowing a low threshold of frequency of to be passed, blocking a high threshold of and vice versa. There was resampled output increased to 150% preceded by filtering. The filter coefficients for low pass and high pass Digital FIR filter, through the least square regression method, parks McClellan Algorithm and window methods were employed for easy optimization. More so, there was creation of 2-4-5 filter channel banks through the 2nd-level convolution of their down sampling and up sampling filtering techniques during the multi-irate filtering to ensure the design of error-free Digital FIR Filter using MATLAB File editor(M-File) and tool boxes for writing the C-programming of the design. In the analysis, the mean and standard deviation of the low pass Digital FIR Filter output during decimation and interpolation are (0.26, 6.13) and (0.004,1.22) respectively.