Miracle-dz/UniFAR-FTUs huggingface dataset:
Assessing the Technical, Economic and Policy-centered Feasibility of a Proposed Satellite Communication System for the Developing World

Satellite communication systems remain one of the most under utilized development mediums in less industrialized countries. This research proposes to establish a low cost satellite communications system tailored specifically for the developing world (+/30° latitude). The technical, economic and policy related frontiers of the problem are integrated within a MATLAB based satellite communication constellation simulation which is used to assess the feasibility of the proposed satellite system. The analysis demonstrates that with technical advances that would allow higher capacity systems at lower costs and a renewed policy framework in line with the present state of the satellite system industry, it could be feasible to establish a low earth orbit satellite communications system for the developing world. The inputs to the satellite simulation are the proposed system’s desired design variables and other relevant parameters. The outputs are system performance, capacity and cost. The Pareto optimal solution trade space is generated by the simulation model using a full-factorial run that probes the entire design space. The application of choice is short messaging services (SMS), chosen for its ability to provide proven connectivity at moderate costs. The capacity and cost of the most ideal Pareto architecture is contrasted against demand in the defined developing world region. The simulation also accounts for the necessary policy considerations and assesses the feasibility of the proposed system amidst the existing industry policy and regulatory framework. Additionally, data regarding the current economic standing of the region and how this forms an underlying basis for the digital divide is presented and assessed. The policy and regulatory constraints on the acceleration of telecommunications development throughout the developing world are discussed. This thesis elaborates upon the need for a focus on design for affordability if satellite communication systems are to realize their immense potential for the delivery of needed social services to the world’s marginalized. Thesis Supervisor :Olivier L. de Weck Title :Robert N. Noyce Assistant Professor of Aeronautics and Astronautics and Engineering Systems
The Performance of ECC Algorithms in DNSSEC: A Model-based Approach

The Domain Name System (DNS) resolves domain names to IP addresses on the Internet. Several vulnerabilities in DNS led to the development and deployment of a secure extension, DNSSEC, which provides authentication and data integrity by including digital signatures in DNS responses. DNSSEC has its own flaws however, of which DDoS amplification potential, fragmentation related issues and deployment complexity are the most severe ones. Where the RSA signature scheme is currently widely deployed in DNSSEC, its elliptic curve (ECC) alternative, Elliptic Curve Digital Signature Algorithm (ECDSA), is more recently standardized and supposedly reduces the aforementioned flaws, by reducing the size of digital signatures and cryptographic keys. EdDSA is another, more recent, digital signature scheme based on elliptic curve cryptography, and has even more promising properties (e.g. smaller key size). The major drawback of ECC is that the validation of signatures is computationally more intensive than RSA. A transition from RSA towards ECC would introduce a significant increase in computational load caused by signature validations for DNS resolvers. While some simple benchmark tests confirm that a single ECC validation is computational costly, there exists no scientific proof that ECC can be deployed on a large scale without causing any performance issues. In our research we have developed a DNSSEC model based on measurement from three deployed resolvers. The resulting regression model was applied to evaluate several scenarios, both current and future scenarios. Based on the scenarios, we can conclude that the switch towards ECC can be made without encountering any computational related issues for validating resolvers. This research was conducted in collaboration with SURFnet, the Dutch national research and education network which provides Internet and services to the research and education community in the Netherlands.
Steering pull and drift considering road wheel alignment tolerance during high-speed driving

This paper describes an analytical vehicle model and a full-vehicle model that consider the effect of suspension geometry on steering pull and drift. Steering pull occurs when a driver applies steering wheel torque to keep a straight-line course, and steering drift means the tendency to deviate from the intended path with a free steering wheel. In designing a chassis system, it is crucial to establish a suspension insensitive to steering pull and drift regardless of manufacturing tolerances. Simulation results show that larger caster trail at the front wheel leads a less-sensitive vehicle towards steering pull and drift, since caster trail reduces the equilibrium slip angle difference between pull and drift by considerably changing the aligning moment diagram. These wheel alignment sensitivities are validated by experimental measurement of drift distance.
A novel evaluation method of societal benefits of ultra high voltage power grid optimizing power energy allocation

Although Ultra High Voltage (UHV) power grid requires heavy investment, it can also produce vast social economic benefits by optimizing power energy allocation. Owing to the existing controversy over the economy of the UHV power grid, it is necessary for policymakers to propose a scientific method used to comprehensively analyze huge costs and benefits caused by the UHV power grid. In this paper, Life Cycle Cost (LCC) is introduced to analyze cost dimensions of the UHV power grid and shadow price theory is used to evaluate huge potential social benefits brought by UHV power grid. Based on these shadow prices, social benefits of UHV power grid are put forward from aspects of saving installation benefit, saving coal-fired benefit, power loss reduction benefit, short-circuit current reduction benefit, sustainable development benefit, and social resource distribution optimization benefit. Some evaluation indexes for social benefits based on input-output analysis table of the LCC mode are calculated to be comparable with those of the traditional cost mode. A certain UHV power grid of China is applied to verify the effectiveness and feasibility of the proposed evaluation method.
Characterization and simulation of GaSb device-related properties

Device related parameters of GaSb are characterized and simulated based on measurements of photovoltaic cells. Internal quantum efficiencies are simulated to quantify the contributions from band-gap narrowing and the main recombination mechanisms, such as Auger, radiative, and Shockley-Read-Hall recombination. A detailed study of the recombination mechanisms values shows differences between literature data and data derived from comparison of simulation results with measurements on real devices. A new evaluation of these data is given. The evaluation of the band-gap narrowing in n-GaSb is performed by comparison of measurements and simulations of the injection component of the dark current I/sub 01/ and open-circuit voltage. For the first time, a range of possible values for the intrinsic carrier concentration of GaSb at room temperature is given, based on theoretical calculations, and proven with comparison of measured lot and open-circuit voltages of GaSb photovoltaic devices.
Comparative study of product design strategy and related design issues

The design strategies employed by Taiwanese home appliance companies after Taiwan's entry to the World Trade Organization were investigated in a previous study by the authors. That study identified three strategic design groups: a passive-response group, an aggressive-response group, and an R&D-focused group. This study further explores the difference in design strategy-related issues such as product development types, emphasizing features, motivation, and advertising appeal of new product design projects among these three strategic design groups. Analytical results demonstrate that differences exist among the three groups for strategy-related issues.
Essential role of MALAT1 in reducing traumatic brain injury

As a highly evolutionary conserved long non-coding RNA, metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was first demonstrated to be related to lung tumor metastasis by promoting angiogenesis. To investigate the role of MALAT1 in traumatic brain injury, we established mouse models of controlled cortical impact and cell models of oxygen-glucose deprivation to mimic traumatic brain injury in vitro and in vivo. The results revealed that MALAT1 silencing in vitro inhibited endothelial cell viability and tube formation but increased migration. In MALAT1-deficient mice, endothelial cell proliferation in the injured cortex, functional vessel density and cerebral blood flow were reduced. Bioinformatic analyses and RNA pull-down assays validated enhancer of zeste homolog 2 (EZH2) as a downstream factor of MALAT1 in endothelial cells. Jagged-1, the Notch homolog 1 (NOTCH1) agonist, reversed the MALAT1 deficiency-mediated impairment of angiogenesis. Taken together, our results suggest that MALAT1 controls the key processes of angiogenesis following traumatic brain injury in an EZH2/NOTCH1-dependent manner.
Population structure, intergroup interaction, and human contact govern infectious disease impacts in mountain gorilla populations

Infectious zoonotic diseases are a threat to wildlife conservation and global health. They are especially a concern for wild apes, which are vulnerable to many human infectious diseases. As ecotourism, deforestation, and great ape field research increase, the threat of human‐sourced infections to wild populations becomes more substantial and could result in devastating population declines. The endangered mountain gorillas (Gorilla beringei beringei) of the Virunga Massif in east‐central Africa suffer periodic disease outbreaks and are exposed to infections from human‐sourced pathogens. It is important to understand the possible risks of disease introduction and spread in this population and how human contact may facilitate disease transmission. Here we present and evaluate an individual‐based, stochastic, discrete‐time disease transmission model to predict epidemic outcomes and better understand health risks to the Virunga mountain gorilla population. To model disease transmission we have derived estimates for gorilla contact, interaction, and migration rates. The model shows that the social structure of gorilla populations plays a profound role in governing disease impacts with subdivided populations experiencing less than 25% of the outbreak levels of a single homogeneous population. It predicts that gorilla group dispersal and limited group interactions are strong factors in preventing widespread population‐level outbreaks of infectious disease after such diseases have been introduced into the population. However, even a moderate amount of human contact increases disease spread and can lead to population‐level outbreaks.
Prediction of Postoperative Sepsis Based on Changes in Presepsin Levels of Critically Ill Patients with Acute Kidney Injury after Abdominal Surgery

Presepsin (PSP) is a viable biomarker for the detection of bacterial infection, but it lacks accuracy when acute kidney injury (AKI) develops. Herein, we evaluated the diagnostic and prognostic value of PSP in predicting postoperative sepsis after abdominal surgery respective to the degree of AKI. A total of 311 patients who underwent abdominal surgery and were admitted to a surgical intensive care unit were enrolled and classified into non-AKI, mild-AKI (stage 1, stage 2 and stage 3 without renal replacement therapy (RRT)) and severe-AKI (stage 3 with RRT) group, according to the Kidney Disease Improving Global Outcomes criteria. In each group, PSP and other biomarkers were statistically analyzed between non-sepsis and postoperative sepsis at the admission (T0), 24 h (T1), 48 h (T2) and 72 h (T3) after surgery. In non-AKI and mild-AKI group, PSP levels were significantly higher in postoperative sepsis than non-sepsis group, whereas no difference was detected in the severe-AKI group. Cutoff values of PSP in the mild-AKI group for the prediction of postoperative sepsis were 544 pg/mL (AUC: 0.757, p < 0.001) at T0 and 458.5 pg/mL (AUC: 0.743, p < 0.001) at T1, significantly higher than in non-AKI group. In multivariate analysis, predictors of postoperative sepsis in the mild-AKI group were PSP at T2 (odds ratio (OR): 1.002, p = 0.044) and PSP at T3 (OR: 1.001, p = 0.049). PSP can be useful for predicting newly developed sepsis in patients with transient AKI after abdominal surgery with modified cutoff values.
ADP based trajectory-tracking control via backstepping method for underactuated AUV with unknown dynamics

This paper investigates trajectory-tacking control problem for underactuated autonomous underwater vehicles (AUV) with unknown dynamics. Different from existing adaptive dynamic programming (ADP) schemes, our proposed control scheme can achieve high-level system stability and tracking control accuracy. Firstly, the backstepping approach is introduced into the kinematic model of underactuated AUV and produces a virtual velocity control which is taken as the desired velocity input of the dynamic model of underactuated AUV. Secondly, the error tracking system is constructed according to the dynamic model of underactuated AUV. Thirdly, the critic neural network and the action neural network are employed to transform the trajectory-tracking control problem into optimal control problem based on policy iteration algorithm. At last simulation results are given to verify the effectiveness of the control scheme proposed in this paper.
Photonic integrated circuits for quantum communication and computation

In this paper we propse various applications of guided wave optics to quantum optics experiments. An immediate application concerns entangled photon sources. Long term objectives will be mulitparticle (n>2) and multiport configurations, needed for quantum error-correction. We show how guided wave optics, incorporating both integrated optics and fiber optics, could provide a realistic means of constructing experiments and devices.
Estimation of direct and maternal genetic parameters for weaning weight in Hungarian Simmental cattle

The aim of the current research was to estimate variance components and genetic parameters of weaning weight in Hungarian Simmental cattle. Weaning weight records were obtained from the Association of Hungarian Simmental Breeders. The dataset comprised of 44,278 animals born from 1975 to 2020. The data was analyzed using the restricted maximum likelihood methodology of the Wombat software. We fitted a total of six models to the weaning weight data of Hungarian Simmental cattle. Models ranged from a simple model with animals as the only random effect to a model that had maternal environmental effects as additional random effects as well as direct maternal genetic covariance. Fixed effects in the model comprised of herd, birth year, calving order and sex. Likelihood ratio test was used to determine the best fit model for the data. Results indicated that allowing for direct-maternal genetic covariance increases the direct and maternal effect dramatically. The best fit model had direct and maternal genetic effects as the only random effect with non-zero direct-maternal genetic correlation. Direct heritability, maternal heritability and direct maternal correlation of the best fit model was 0.57, 0.16 and -0.78 respectively. The result indicates that problem of (co-)sampling variation occurs when attempting to partition additive genetic variance into direct and maternal components.
CONTRIBUTION TO THE STUDY OF HCR GEARING PROPERTIES FROM WARM SCUFFING DAMAGE POINT OF VIEW

The issue of design and dimensioning of HCR gearing, particularly of the gearings with an internal engagement, it nowadays, especially in the design of hybrid cars drives, highly topical. This kind of gearing has many advantages in operation, but at the same time it is more complicated in stage of its design and load capacity calculation. Authors in this contribution present some results of temperature scuffing research of internal and external HCR gearing. There are given the equations for calculation of warm scuffing resistance of both external and internal HCR gearing derived according to the integral temperature criterion.
Modeling erbium-doped fiber amplifiers

Erbium-doped fiber amplifiers are modeled using the propagation and rate equations of a homogeneous two-level laser medium. Numerical methods are used to analyze the effects of optical modes and erbium confinement on amplifier performance, and to calculate both the gain and amplified spontaneous emission (ASE) spectra. Fibers with confined erbium doping are completely characterized from easily measured parameters: the ratio of the linear ion density to fluorescence lifetime, and the absorption of gain spectra. Analytical techniques then allow accurate evaluation of gain, saturation, and noise in low-gain amplifiers (G >
The transport of bioaerosols observed by wideband integrated bioaerosol sensor and coherent Doppler lidar

Abstract. Bioaerosols are usually defined as aerosols derived from biological systems such as bacteria, fungi, and viruses. They play an important role in atmospheric physical and chemical processes including ice nucleation and cloud condensation. As such, their dispersion affects not only public health but regional climate as well. Lidar is an effective technique for aerosol detection and pollution monitoring. It is also used to profile the vertical distribution of wind vectors. In this paper, a coherent Doppler wind lidar (CDWL) was deployed for wind and aerosol detection in Hefei, China, from 11 to 20 March in 2020. A wideband integrated bioaerosol sensor (WIBS) was deployed to monitor variations in local fluorescent bioaerosol levels. During observation, three aerosol transport events were captured. The WIBS data show that during these transport events, several types of fluorescent aerosol particles exhibit abnormal increases in either their concentration, number fractions to total particles, or number fractions to whole fluorescent aerosols. These increases are attributed to transported external fluorescent bioaerosols instead of local bioaerosols. Based on the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) backward trajectory model and the characteristics of external aerosols in WIBS, their possible sources, transport paths, and components are discussed. This work proves the influence of external aerosol transport on local high particulate matter (PM) pollution and fluorescent aerosol particle composition. The combination of WIBS and CDWL expands the aerosol monitoring parameters and proves to be a potential method for the real-time monitoring of fluorescent biological aerosol transport events. It contributes to the further understanding of bioaerosol transport.
UAV-Based Mapping of Banana Land Area for Village-Level Decision-Support in Rwanda

Crop monitoring is crucial to understand crop production changes, agronomic practice decision-support, pests/diseases mitigation, and developing climate change adaptation strategies. Banana, an important staple food and cash crop in East Africa, is threatened by Banana Xanthomonas Wilt (BXW) disease. Yet, there is no up-to-date information about the spatial distribution and extent of banana lands, especially in Rwanda, where banana plays a key role in food security and livelihood. Therefore, delineation of banana-cultivated lands is important to prioritize resource allocation for optimal productivity. We mapped the spatial extent of smallholder banana farmlands by acquiring and processing high-resolution (25 cm/px) multispectral unmanned aerial vehicles (UAV) imageries, across four villages in Rwanda. Georeferenced ground-truth data on different land cover classes were combined with reflectance data and vegetation indices (NDVI, GNDVI, and EVI2) and compared using pixel-based supervised multi-classifiers (support vector models-SVM, classification and regression trees-CART, and random forest–RF), based on varying ground-truth data richness. Results show that RF consistently outperformed other classifiers regardless of data richness, with overall accuracy above 95%, producer’s/user’s accuracies above 92%, and kappa coefficient above 0.94. Estimated banana farmland areal coverage provides concrete baseline for extension-delivery efforts in terms of targeting banana farmers relative to their scale of production, and highlights opportunity to combine UAV-derived data with machine-learning methods for rapid landcover classification.
A physics-based dynamic thermal impedance model for vertical bipolar transistors on SOI substrates

A physics-based compact model for the thermal impedance of vertical bipolar transistors, fabricated with full dielectric isolation, is presented. The model compares favorably to both three dimensional (3-D) ANSYS(R) transient simulations and measurements. Using the software package Thermal Impedance Pre-Processor (TIPP), a multiple-pole circuit can be fitted to the thermal impedance model. The thermal equivalent circuit is used in conjunction with a modified version of SPICE to give efficient electrothermal simulations in the dc and transient regimes.
Frailty and Different Exercise Interventions to Improve Gait Speed in Older Adults after Acute Coronary Syndrome

Background and Objectives: The world’s population is rapidly aging, and it is estimated that, by 2050, every sixth person on earth will be older than 65 years. Around 30% of older adults entering cardiac rehabilitation (CR) meet the criteria of frailty. Frailty identification has not been included in the routine evaluation of CR patients yet, and there is a lack of evidence on what training regimen for improving physical performance in frail people is optimal. Therefore, the aim of our study was to determine the prevalence of frailty and to evaluate the effect of two different complementary training programs on the gait speed of older vulnerable and frail patients with acute coronary syndrome and mid-range-to-preserved left ventricular ejection fraction (≥40%) during short-term CR. Materials and Methods: This randomized controlled trial was conducted from January 2020 to September 2021. CR participants (n = 97) with a mean age of 73.1 ± 5.3 years were randomly allocated into three groups: control (CG, n = 32), intervention-1 (IG-1, n = 32) and intervention-2 (IG-2, n = 33). The patients of all three groups attended a usual inpatient CR program, and two intervention groups additionally received different resistance and balance training programs 3 days a week: the IG-1 underwent complementary training with traditional means of physical therapy, while the IG-2 underwent complementary training with mechanical devices. The mean CR duration was 18.9 ± 1.7 days. Frailty was assessed with the Edmonton Frail Scale, and the 5 m walk test was used to evaluate gait speed. Results: Frailty was determined in 37.1% of participants, and 42.3% met the criteria of being vulnerable. After CR, the gait speed of frail and vulnerable patients significantly improved in all three groups (p < 0.05). In the IG-2, slow gait speed was reversed to normal in the overwhelming majority of patients (p < 0.05), while the CG had the greatest proportion of patients who remained to be slow after CR (p < 0.05). Conclusions: A considerable part of patients entering CR are frail or vulnerable; therefore, it is of crucial importance to assess frailty status in all older people. All three CR programs improved gait speed in frail and vulnerable older patients with ischemic heart disease. Complementary resistance and balance training with mechanical devices more effectively reversed slow gait speed to normal during short-term CR.