Miracle-dz/UniFAR-FTUs huggingface dataset:
Blunt and sharp notch behaviour of Glare laminates

Glare laminates are materials that consist of alternating aluminium and glass prepreg layers especially designed for aeroplane structures. The result is a material that combines the properties of its constituents and the properties of a bonded structure. Some of the favourable characteristics of Glare are its fatigue, impact and fire resistance properties and the possibility to create tailored design solutions. After 25 years of development and extensive investigations within the aerospace environment, Glare is now ready to be applied for industrial production. It will be applied in large parts of the new Airbus A380 fuselage, which is planned to have its first flight in 2004. This research describes the behaviour of Glare with holes that are made within production and the behaviour when the material is damaged due to an impact like for example a bird strike or an engine seperationf what creates cracks. These holes and this damage are regarded as blunt and sharp notches respectively. The failure mechanisms that were observed are investigated and function as the basis for the development of engineering calculation methods for the blunt and sharp notch behaviour of arbitrary Glare laminates. Additional research concerning the behaviour of spliced Glare laminates in the presence of notches, the presence of a crack in a row of holes and the development of Glare with crack stoppers is presented.
Volume Calculation for Power Equipment Point Cloud Based on Concave Hull Slice Method

Calculation of volume has great influence on the measurement of power equipment. However, it is difficult to measure the volume of complex equipment in the electric power industry. To solve this problem, an improved volume calculation method based on adaptive concave slice method is proposed in this paper. Firstly, the point cloud slices are obtained by adaptive slicing along the coordinate axis. Then, the k-nearest neighbor method is used to search the outer boundary contour of the slice to obtain the concave polygon, which calculates the area of the polygon and the volume of the slice. Finally, the overall volume of the point cloud is obtained by summing up the volume of all slices. The experimental results show that the method is effective for the calculation of complex power equipment.
MBPC controller for UGV Trajectory Tracking

In this paper, the development of a tracking trajectories system for a skid-steering type agricultural vehicle based on predictive control is presented. Since the vehicle operates outdoors, a high precision measurement of the geolocation and orientation is needed, therefore, a Kalman filter was designed. That filter fusions the data of position and orientation from an inertial measurement unit (IMU), wheel encoders and GPS (Global Positioning System) mounted on the vehicle. On the other hand, for the autonomous tracking trajectories, two controllers were designed: first, a proportional controller for the linear speed, and second, a model based predictive controller (MBPC) for the vehicle heading angle. For the design of the MBPC, a dynamical model of the vehicle direction was obtained using a gray box modeling, additionally, an incremental state space model strategy was use to design and deploy the MBPC. Finally, the results show that the developed control strategy presents a good performance with a RMSE of 1.038m in tracking outdoor trajectories.
Numerical modelling in assessment of different colorectal cancer cell lines behavior in treatment with cisplatin

Colorectal cancer is one of the most common types of cancer and metastasis particular problem in anticancer treatment. Therefore, it is crucial to understand key steps in metastasis formation, such as loss of adherent junctions. $\mathbf{E}$ -cadherin and $\beta$ -catenin are proteins involved in cell-cell junctions in cancer cells. Present study aimed to explain changes in E-cadherin and $\beta$ -catenin in two colorectal cancer cell lines after treatment with standard anticancer drug cisplatin, by using numerical modelling. The validity of the mathematical model was tested by experimental measurement of E-cadherin and $\beta$ -catenin protein expression by immunofluorescent method. Our results shows that the numerical model of the Wnt pathway completely confirms experimental results for HCT-116 cells, while for SW-480 cells this model should be adjusted.
Operation and Design of Ferroelectric FETs for a BEOL Compatible Device Implementation

We present a study based on numerical simulations and comparative analysis of recent experimental data concerning the operation and design of FeFETs. Our results show that a proper consideration of charge trapping in the ferroelectric-dielectric stack is indispensable to reconcile simulations with experiments, and to attain the desired hysteretic behavior of the current-voltage characteristics. Then we analyze a few design options for polysilicon channel FeFETs and, in particular, we study the influence of the channel thickness and doping concentration on the memory window, and on the ratio between the polarization dependent, high and low resistance state.
Effect of Radio Channel and Antennas on Physical-Layer-Security Key Exchange

The wireless channel is inherently an open medium which exposes wireless communication users to the risk of interception. The vulnerabilities of the wireless channel have led to the search for innovative and efficient security solutions at different levels of the network protocol. In particular, the physical layer level allows for implementing some security functions, such as key generation and exchange, by exploiting the intrinsic randomness of the wireless communication channel. In this paper, we analyze the effect of wireless channel and of antenna characteristics on physical layer security (PLS) key generation. The aim is to put in evidence the relation between physical quantities, such as radio channel characteristics or antenna directivity, with higher level secrecy performance indicators, such as the key mismatch between the different communication nodes and the key randomness. For this purpose, we developed a comprehensive numerical model, which implements all the different steps, from signal generation and wireless propagation modeling to key generation through spectral quantization. The reported results show that the multipath richness of the radio channel, as in outdoor urban scenarios, improves the PLS secrecy performances with respect to simpler propagation scenarios. Moreover, we show that the use of more directive antennas in the legitimate communication link improves secrecy. An opposite effect is achieved when the directivity of the eavesdropper antenna is increased, thus improving its ability to perform passive attacks.
A Genetic Algorithm-Based Metaheuristic Approach for Test Cost Optimization of 3D SIC

Demand for small, multi-functional, high performance electronic product with less power consumption is increasing rapidly. To meet the demand, IC design has been shifted from two dimensional integrated circuit (2D-IC) to three dimensional integrated circuit (3D-IC), where multiple device layers are stacked together to create stacked integrated circuit (SIC). This results the complexity in 3D SIC architecture and increase in the number of fault-sites. Therefore, testing of SIC has become complicated. Consequently, the test data volume also grows in proportion to the number of cores in the SIC, since each core is associated with one or more tests, which leads to longer test times. Test cost of IC which depends on test time, associated hardware to test the cores and the power dissipated at the time of test, can be represented as a weighted sum of test time and the associated hardware to test the core with power considered as the test constraint. As a result an efficient test plan is required to co-optimize test time and hardware under certain power constraint. The objective of our work is to design an efficient test plan both for non-stacked IC (i.e. SIC with single chip) and 3D stacked IC (i.e. SIC with multiple chips) under a power constraint, where each chip is provided with IEEE 1149.1 architecture. An existing cost model is used for calculating the test cost. Initially we propose First fit based two dimensional (2D) Bin Packing optimization algorithm for minimizing the test cost of non-stacked IC. However, the method produces sub-optimal result in comparison to earlier reported work. Knowing the complexity of 3D SIC, Genetic algorithm based metaheuristic approach is next proposed in this paper. It is applied on several ITC02 benchmark circuits and the experimental result shows the efficacy of the proposed algorithm in comparison to earlier works.
Success Factors & Challenges for Mobile Collaborative Learning Implementation in Higher Education

In the last decade, the mobile device has expanded exponentially, and 95 percent of the world's population now lives in a region served by a mobile cellular network. Collaboration in learning can provide opportunities for skill practice and the development of new knowledge and partnerships both within and outside of the classroom and in environments where there are no classes or other gathering places, or collaborative events. However, there is an inefficient use of mobile learning mobility opportunities, a lack of interaction and direct engagement, a lack of experience, and a lack of awareness about the university's effectiveness and applicability. In this article, we offer a comprehensive literature review of how mobile collaborative learning in higher education works, emphasizing the challenges and success factors that have been identified. We conducted a comprehensive study of the literature on mobile collaborative learning. Our keyword search found 621 papers from the years 2016 to 2021. We excluded studies and removed the duplicates into 37 papers. The majority of the papers included in this study were from Q1 journals (48,5%). We found 62 success factors that were grouped into 5 categories. Design, interactivity, usability, user perception, ease of use, satisfaction, usefulness, communication, and interaction are the most salient success factors. While challenges grouped into 11 categories including motivation, satisfaction, UI/UX design, usability, framework, integration, sentiments, security, algorithm, multimedia and critical thinking skill.
Use of CDF Functions for Evaluating GNSS Antennas Radiation Performance

For GNSS applications, radiation over upper hemisphere is a critical performance metric. At present, this is mainly captured in peak gain and half-power beam width indexes, which have some inherent weaknesses. In this paper, the use of cumulative distribution functions (CDFs) and associated 80% coverage threshold are employed as important index to evaluate the radiation performance of GNSS antenna. Sample patterns from reference antennas are simulated and analyzed to show how the new measurement index works. The simulated results demonstrated the new index could represent expected radiation performance over upper hemisphere better. Therefore, the proposed minimum gain at the 80%-tile CDF, is believed to be good supplementary to existing metrics.
Eddy Correlation Systems for Measuring EVAPOTRANSPIRATION

ABSTRACT A portable eddy correlation system was used to make direct, real-time mfeasurements of evapotranspiration over irrigated alfalfa. T^e surface energy balance equation was used to evaluate system performance, with the closure ratio defined as the ratio of the sum of latent and sensible heat fluxes to the sum of net radiation and soil heat flux. For six 24-hour periods, the mean uncorrected closure ratio was 0.85. After corrections were made for sensor separation, the mean closure ratio improved to 0.95. Measurements were made during several other periods, however, sensor malfunctions resulted in erroneous data during these periods. Care was required in deploying and maintaining the instruments, but the system proved to be a viable alternative for making real-time evapotranspiration measurements with portable equipment. KEYWORDS. Evapotranspiration, Eddy correlation. Irrigation, Measurement, Sensors.
Predicting the Performance of Mathematics’ Students through Data Mining Techniques for Enhanced Education Systems

In this study, we use data mining techniques to predict the performance of students in mathematics. The failure rate in secondary education within the discipline of mathematics is significant. Therefore, predicting the performance of students is relevant to support the decision plan on interventions. A dataset with 395 records collected from two secondary schools in Portugal was used in this work. The authors tested eight machine learning algorithms such as Stochastic Gradient Descent, AdaBoost, Support Vector Machine, Naïve Bayes (NB), K-Nearest Neighbors algorithm, Decision Tree, and Logistic Regression. Consequently, this work supports future research activities to use NB to predict students’ performance. Moreover, this work has ranked the impact of the variables which most disturb students from achieving success. The results recommend the NB algorithm using the top five important features which report 75.22%, 74.41%, 75.22%, and 73,29% of accuracy, precision, recall, and F1-Score, respectively. By predicting students’ performance is possible to plan interventions on time and, consequently, increase the final discipline score.
Direct Lightning Impact Assessment on a Rural Mini-Grid of Nepal

Lightning-related damage to overhead medium-voltage distribution networks is one of the prime concerns in power systems. This paper discusses distribution network modeling techniques required for lightning studies. The presented models of lightning current, line conductors, line insulators, distribution poles, grounding, distribution transformers, and surge arresters have been used for a direct lightning simulation case study. The case study is done in an eight kilometers long rural mini-grid of Nepal, where seven synchronous generators and seven distribution transformers are closely located. From this study, the dead-end low-voltage side and the midway medium-voltage side were found to be most stressed. So, it is recommended to use appropriate arresters at the low-voltage side of dead-end distribution transformers specifically to protect generators and low-voltage consumer appliances. Similarly, higher energy duty arresters can be installed at the medium-voltage bushing of midway transformers for better performance and reliability.
Secure and Reliable WSN for Internet of Things: Challenges and Enabling Technologies

Wireless Sensor Network (WSN) is an innovative technology with a broad range of applications and highly attractive benefits, such as low cost of implementation and data transmission, unmonitored access to the network, autonomous and long-term operation. With extensive demand for the advancement of related technologies (cloud computing, near-field communications and cellular mobile networks), the Internet of Things (IoT) is becoming a very exciting paradigm. By using communication technologies in sensors and sensing features in web devices, WSNs have begun interaction with the Iot devices. IoT provides access to a large amount of information gathered by WSNs. However, the security of WSN and IoT comes at a cost, mainly due to privacy management issues. Therefore, this paper offers a comprehensive analysis of security threats against WSN and IoT, along with the strategies for preventing, detecting and mitigating those threats. The related defense mechanisms can help in building a safe IoT expansion and widespread understanding by getting familiar with the details of these attacks. The aim of this paper is to address and demonstrate the impact of the security problems on WSNs from the viewpoint of the IoT and its applications. In the analysis carried out for this work, a classification of available attacks and threats against these requirements has also been included.
Invariance and Sliding Modes. Application to coordination of multi-agent systems, bioprocesses estimation, and control in living cells

The present Thesis employs ideas of set invariance and sliding modes in order to deal with different relevant problems in control of nonlinear systems. Initially, it reviews the techniques of set invariance as well as the more relevant results about sliding modes control. Then the main methodologies used are presented: sliding mode reference conditioning, second order sliding modes and continuous approximation of sliding modes. Finally, the methodologies are applied to different problems in control theory and to a variety of biologically inspired applications. The contributions of the thesis are: -The development of a method to coordinate dynamical systems with different dynamic properties by means of a sliding mode auxiliary loop shaping the references given to the systems as function of the local and global goals, the achievable performance of each system and the available information of each system. -The design of tuning methods for second order sliding mode algorithms. The methods decouple the problem of stability analysis from that of finite-time convergence of the super-twisting sliding mode algorithm. A nonlinear change of coordinates and a time-scaling are used to provide simple, yet flexible design methods and stability proofs. Application of the method to the design of finite-time convergence estimators of bioprocess kinetic rates and specific biomass growth rate, from biomass measurements. Also the estimators are validated with experimental data. -The proposal of a strategy to reduce the variability of a cell-to-cell communication signal in synthetic genetic circuits. The method uses set invariance and sliding mode ideas applied to gene expression networks to obtain a reduction in the variance of the communication signal. Experimental approaches available to modify the characteristics of the gene regulation function are described.
Dual-polarization and Wideband Metasurface with Eight OAM Beams

This paper presents a dual-polarized and wideband metasurface, which can achieve dual-polarized vortex beams carried with orbit angular momentum (OAM) working at 13-15.5GHz. The element can shift 513° phase at 15GHz, independently for both x- and y-polarization. When a horn radiates a 45° linearly polarized wave to the metasurface, multiple x- and y- polarized vortex beams can be respectively reflected. To verify this, we design three kinds of reflectarray to generate multiple OAM beams, including dual-beam, quad-beam and eight-beam with polarization multiplexing. To validate the proposed reflective metasurface, one is fabricated and measured. The measured results show that the reflectarray can achieve high gain 19 dBi, high aperture efficiency 11.54%.
3D DoA-based Localization with Phase Jump Corrections

Localizing a source based on the directions of its signals is an attractive approach because no synchronization among clocks is required. In this paper, we propose a Maximum Likelihood (ML) estimator to solve the location problem in 3D schemes, where a signal's direction is mathematically expressed by an elevation angle and an azimuth angle which applies iterative procedures for position estimation. This estimator applies iterative procedures for position estimations. To avoid confusions, the value of each angle must be predefined in an interval of 2 $\pi$ - length. However, the convergence of iterative procedures will be really challenging if there are angle estimation errors caused by noisy measurements with values near the boundaries of this interval. In our proposed procedure, the elevation angle is defined with the arctan function and the azimuth angle is defined with the atan2 function, whose codomain is $2\pi$-long, to map the DoA. Furthermore, to robustify the estimations near the boundaries, phase jump corrections are proposed to rectify the final estimates. Simulation results show significant performance improvements.
ITDBERT: Temporal-semantic Representation for Insider Threat Detection

The objective and universal nature of user behavior data make it the primary data for insider threat detection. Existing solutions treat user behavior as atomic symbols and do not consider behavior semantic information. Meanwhile, fine-grained temporal information is ignored despite its relevance to describe user behavior. Such approaches inevitably lead to unsatisfactory performance and generalization. In this paper, we propose ITDBERT which embeds temporal information into behavior and catches the fused semantic representation via pre-trained language models. ITDBERT also leverages attention-based Bi-LSTM to provide behavior-level detection results. To verify the effectiveness of our proposed method, we conduct comparison experiments on Cert datasets. Our proposed model achieves an F1-score of 0.9243 in day-level insider threat detection, which outperforms baselines.
A Broadband 4×4 Butler Matrix with Tunable Phase Shifters Group

A broadband 4×4 Butler matrix with cascaded tunable shifters, capable of providing 16 switchable differential phases, is proposed in this paper. First, a single layer broadband 4x4 Butler matrix is designed. By using the broadband 3-dB hybrid coupler and broadband 45° /0° shifter, a Butler matrix with phase imbalance of ±3° can be obtained from 2.3 GHz to 2.5 GHz (±5° from 2.12 GHz to 2.57). Then a tunable shifters group is designed to produce 0°, ±22.5°, 45° phase shifts. By combining the broadband Butler matrix with the tunable phase shifters group, a 4×4 Butler matrix which can produce 16 differential phases is designed and simulated for demonstration.
Effect of Random Thermal Spikes on Stirling Convertor Heater Head Reliability

Onboard radioisotope power systems being developed to support future NASA exploration missions require reliable design lifetimes of up to 14 yr and beyond. The structurally critical heater head of the high-efficiency developmental Stirling power convertor has undergone extensive computational analysis of operating temperatures (up to 650 C), stresses, and creep resistance of the thin-walled Inconel 718 bill of material. Additionally, assessment of the effect of uncertainties in the creep behavior of the thin-walled heater head, the variation in the manufactured thickness, variation in control temperature, and variation in pressure on the durability and reliability were performed. However, it is possible for the heater head to experience rare incidences of random temperature spikes (excursions) of short duration. These incidences could occur randomly with random magnitude and duration during the desired mission life. These rare incidences could affect the creep strain rate and therefore the life. The paper accounts for these uncertainties and includes the effect of such rare incidences, random in nature, on the reliability. The sensitivities of variables affecting the reliability are quantified and guidelines developed to improve the reliability are outlined. Furthermore, the quantified reliability is being verified with test data from the accelerated benchmark tests being conducted at the NASA Glenn Research Center.