Miracle-dz/UniFAR-FTUs huggingface dataset:
Point visibility graphs and restricted-orientation polygon covering

A visibility relation can be viewed as a graph: the uncountable graph of a visibility relationship between points in a polygon P is called the point visibility graph (PVG) of P. In this thesis we explore the use of perfect graphs to characterize tractable subproblems of visibility problems. Our main result is a characterization of which polygons are guaranteed to have weakly triangulated PVGs, under a generalized notion of visibility called 0-visibility. Let 0 denote a set of line orientations. Rawlins and Wood call a set P of points 0-convex if the intersection of P with any line whose orientation belongs to 0 is either empty or connected; they call a set of points 0-concave if it is not 0-convex. Two points are said to be 0-visible if there is an 0-convex path between them. A polygon is 0-starshaped if there a point from which the entire polygon is 0-visible. Let 0' be the set of orientations of minimal 0-concave portions of the boundary of P. Our characterization of which polygons have weakly-triangulated PVGs is based on restricting the cardinality and span of 0'. This characterization allows us to exhibit a class of polygons admitting an O(ns) algorithm for 0-convex cover. We also show that for any finite cardinality 0 , 0-convex cover and 0-star cover are in NP, and have polynomial time algorithms for any fixed covering number. Our results imply previous results for the special case of 0 = { 0,90 ) of Culberson and Reckhow, and Motwani, Raghunathan, and Saran. Two points are said to be link-2 visible if there is a third point that they both see. We consider the relationship between link-2 0-convexity and 0-starshapedness, and exhibit a class of polygon/orientation set pairs for which link-2 0-convexity implies Just because some of us can read and write and do a little math, that doesn't mean we deserve to conquer the Universe. -Kurt Vonnegut, Hocus Pocus
Biogeography-Based Optimization Algorithm for Optimal Operation of Reservoir Systems

AbstractThe optimal operation of reservoir systems to meet water demand is a complex and nonlinear problem. This paper applies the biogeography-based optimization (BBO) algorithm to solve reservoir operation problems. The BBO algorithm is first verified with the minimization of three mathematical benchmark functions (Sphere, Rosenbrock, and Bukin6). In addition, the BBO algorithm was applied to a single reservoir system and a four-reservoir system. The performance of the BBO algorithm was compared with that of the genetic algorithm (GA) in solving the three optimization problems. The results show that the BBO algorithm minimized the benchmark functions accurately, and outperformed the GA in this respect. In the case of the single-reservoir hydropower optimization problem the BBO reached a near-optimal solution. The values of the objective function averaged 1.228 and 1.746 with the BBO and GA, respectively. The global solution of this problem with the nonlinear programming method equals 1.213. In the four-.
A Robust Predictive Speed Control for SPMSM Systems Using a Sliding Mode Gradient Descent Disturbance Observer

This paper proposes a sliding mode gradient descent disturbance observer-based adaptive reaching law sliding mode predictive speed control (GD-SMPC+ARL) for surface-mounted permanent magnet synchronous motor (SPMSM) systems to achieve outstanding disturbance rejection ability and tracking performance. Firstly, an SPMSM model with disturbance is given by incorporating the lumped disturbances into the q-axis current's coefficient. Then, a stable sliding mode gradient descent disturbance observer (SM-GDDO) is designed to identify the q-axis current's coefficient that varies with the lumped disturbance. Finally, a GD-SMPC+ARL strategy, which utilizes an adaptive reaching law-based cost function, is developed on the basis of the proposed SPMSM model, where the q-axis current's coefficient is estimated by utilizing SM-GDDO and updated at each control period. Compared with conventional reaching laws, the proposed adaptive reaching law suppresses the chattering while maintaining a fast following speed. Simulation and experimental results verify the excellent robustness and tracking performances of the proposed method.
Unmasking the cloak of comorbidities in OSA-association and their severity – a prospective observational study

Background: Obstructive sleep apnoea (OSA) is a common sleep disorder with high prevalence in the community but highly underreported. It is also seen that a significant number of cases with OSA are associated with various comorbidities. The study objective was to estimate and assess the specific type and proportion of various comorbidities seen in association with OSA and association of severity of OSA with comorbidities. Methods: The study was a hospital-based descriptive study of 85 patients with OSA. Descriptive statistics were used to analyse the data and Chi-square test was done to find out the association. Results: The most common comorbidity associated with OSA was obesity (60%). Around half of the patients (49.4%) had severe OSA based on Apnea Hypopnea Index (AHI) scores. Statistically significant association was seen between presence of comorbidities, like diabetes and hypertension, and risk of OSA based on the snoring, tiredness, observed apnea, blood pressure (S.T.O.P) questionnaire. Conclusions: In our study, a significant proportion (73%) of patients with OSA had associated comorbidities at the time of initial diagnosis. This indicates a delayed diagnosis as OSA is diagnosed only after multiple and irreversible comorbidities have developed. A majority (49%) had a severe OSA on initial presentation. This combination of multiple comorbidities and severe OSA at the time on diagnosis is reflective of a huge problem that is peculiar to OSA at large at a community level.
Heart Dysfunction in Essential Hypertension Depends on Systemic Proinflammatory Influences: A Retrospective Clinical Pathophysiological Study

Low-intensity systemic inflammation is an important element of heart failure pathogenesis. The aim of this study is to assess proinflammatory status serum indicators (C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6)) in middle-aged males (M) and females (F) with essential hypertension (HTN) depending on left ventricular (LV) diastolic dysfunction (LVDD). The main group comprised 55 M and 49 F with the first- to second-severity grade HTN with mild heart failure and a preserved LV ejection fraction ≥50%. Patients had sinus rhythm, first or second-severity degree LVDD, LV hypertrophy, left atrium dilatation, and NT-proBNP > 125 pg/mL. Comparison group: 30 hypertensives without cardiac dysfunction; control group: 31 normotensives. Quantitative features were compared using the Mann–Whitney test, median χ2, ANOVA module. Spearman’s rank correlation coefficients were determined to identify the relationship between the proinflammatory pattern and exercise tolerance. Hypertensive M had markedly higher CRP, TNF-α, and IL-6 levels compared to F. All mean values corresponded to reference range. In patients with second-degree LVDD, CRP, TNF-α, and IL-6 levels were significantly greater than in subjects with first-degree LVDD (both within M and within F samples). Significant negative associations between CRP, IL-6, and TNF-α levels and the 6 min walk test existed in hypertensive M and F. The study demonstrated a close relationship between the proinflammatory pattern and LVDD and exercise tolerance indicators, regardless of the hypertensive patient’s sex.
On the Coordination of Transmission-Distribution Grids: A Dynamic Feasible Region Method

Recently, the turnover of energy services between transmission-distribution grids has continued to increase, arousing widespread attention to the efficient coordination between transmission system operator (TSO) and distribution system operator (DSO). The existing literature has characterized the feasible region of distribution networks via equivalent projection methods, which is conducive to the participation of DSO in TSO scheduling. However, the redundant constraints of DSO and the processing of temporal-coupled constraints remain challenging in realistic cases. To achieve an effective interaction between TSO and DSO with least information, we develop a TSO-DSO coordination framework with temporal-coupled constraints embedded, i.e., the concept of dynamic feasible region (DFR). We theoretically derive the polyhedral form of a DFR, which can be characterized as a constraint set formed by the extreme points of the dual space of the DSO optimization program. A novel outer progressive approximation (OPA)-based algorithm is designed to effectively add feasibility cuts until convergence is achieved. To reduce the redundant constraints in the DSO operation model, the enhanced umbrella constraint identification (E-UCI) method is employed. Case studies based on i) a real-world distribution grid in China and IEEE 30-bus system, ii) a Caracas 141-bus distribution network and IEEE 118-bus transmission grid are adopted to validate the effectiveness and computational efficiency of our proposed method.
A Tumoral and Peritumoral CT-Based Radiomics and Machine Learning Approach to Predict the Microsatellite Instability of Rectal Carcinoma

Objective To predict the status of microsatellite instability (MSI) of rectal carcinoma (RC) using different machine learning algorithms based on tumoral and peritumoral radiomics combined with clinicopathological characteristics. Methods There were 497 RC patients enrolled in this retrospective study. The tumoral and peritumoral CT-based radiomic features were calculated after tumor segmentation. The radiomic features from two radiologists were compared by way of inter-observer correlation coefficient (ICC). After methods of variance, correlation, and dimension reduction, six machine learning algorithms of logistic regression (LR), Bayes, support vector machine, random forest, k-nearest neighbor, and decision tree were conducted to develop models for predicting MSI status of RC. The relative standard deviation (RSD) was quantified. The radiomics and significant clinicopathological variables constituted the radiomics-clinicopathological nomogram. The receiver operator curve (ROC) was made by DeLong test, and the area under curve (AUC) with 95% confidence interval (95% CI) was calculated to evaluate the performance of the model. Results The venous phase of CT examination was selected for further analysis because the proportion of radiomic features with ICC greater than 0.75 was higher. The tumoral and peritumoral model by LR algorithm (M-LR) with minimal RSD showed good performance in predicting MSI status of RC with the AUCs of 0.817 and 0.726 in the training and validation set. The radiomic-clinicopathological nomogram performed better in both the training and validation set with AUCs of 0.843 and 0.737. Conclusion The radiomics-clinicopathological nomogram demonstrated better predictive performance in evaluating the MSI status of RC.
Mobile assistive technology with augmented reality for the elderly

Technology offers many possibilities, but older people often do not fully enjoy these opportunities and are frustrated or afraid of these new devices. This has led to their gradual isolation in a society where different forms of communication through the Internet and ICT are essential. In this article, we describe a study conducted during the nacodeal project, which aims to provide technical solutions for the elderly to provide autonomy and better quality of life in their daily activities by integrating information and communication technologies. In order to achieve this goal, advanced augmented reality (RA) technology and Internet services and mobile device interfaces specially designed for the elderly have been developed. These technologies use the underlying structure of most home and geriatric care centers. We propose a prototype system composed of tablet computers and portable RA devices, and analyze the impact of society on user interaction, as well as the evaluation of acceptability and usability. The assessment was conducted through focus groups and individual pilot tests with 48 participants: The elderly, caregivers and experts. His comments concluded that older people have a strong interest and interest in RA based nursing information and communication technologies, especially those related to communication and autonomy.
Extraction and Evaluation: The Viability of the Three Varieties of Banana (Musa Paradisiaca) Exocarps as Potential Sources of Acetic Acid

The banana (Musa paradisiaca) exocarps have been a substantial source for maintaining human health and are the fast-growing herbaceous perennials arising from underground rhizomes. The ripe banana is useful in acidity. This study aimed to evaluate how the banana exocarps from ripe ones, can be made into vinegar. Also, to properly analyze the physicochemical properties (pH and color) and to determine the acetic acid content of the three selected varieties of banana exocarps if it conforms to the set standards. The most accessible in producing acidity is the Latundan (Musa acuminata musa balbisiana AAB Group), but all of the samples are accessible in producing acidity. In pH determination the highest in acidity is Lacatan (Musa acuminata C.) pH 4, while the Cardaba (Musa acuminata balbisiana ABB Group), is pH 3.5, and the lowest is the Latundan pH 3. All of the samples do not have pleasant odor, furthermore the samples well tested and undergo many stages of pasteurization. Thus, the study encourages further development of some spices and food additives and by application of new principles discovered, aside from extending the fermentation time.
In Vivo Bone Tissue Engineering Strategies: Advances and Prospects

Reconstruction of critical-sized bone defects remains a tremendous challenge for surgeons worldwide. Despite the variety of surgical techniques, current clinical strategies for bone defect repair demonstrate significant limitations and drawbacks, including donor-site morbidity, poor anatomical match, insufficient bone volume, bone graft resorption, and rejection. Bone tissue engineering (BTE) has emerged as a novel approach to guided bone tissue regeneration. BTE focuses on in vitro manipulations with seed cells, growth factors and bioactive scaffolds using bioreactors. The successful clinical translation of BTE requires overcoming a number of significant challenges. Currently, insufficient vascularization is the critical limitation for viability of the bone tissue-engineered construct. Furthermore, efficacy and safety of the scaffolds cell-seeding and exogenous growth factors administration are still controversial. The in vivo bioreactor principle (IVB) is an exceptionally promising concept for the in vivo bone tissue regeneration in a predictable patient-specific manner. This concept is based on the self-regenerative capacity of the human body, and combines flap prefabrication and axial vascularization strategies. Multiple experimental studies on in vivo BTE strategies presented in this review demonstrate the efficacy of this approach. Routine clinical application of the in vivo bioreactor principle is the future direction of BTE; however, it requires further investigation for overcoming some significant limitations.
Anomaly Detection Based on Tree Topology for Hyperspectral Images

As one of the most important research and application directions in hyperspectral remote sensing, anomaly detection (AD) aims to locate objects of interest within a specific scene by exploiting spectral feature differences between different types of land cover without any prior information. Most traditional AD algorithms are model-driven and describe hyperspectral data with specific assumptions, which cannot combat the distributional complexity of land covers in real scenes, resulting in a decrease in detection performance. To overcome the limitations of traditional algorithms, a novel tree topology based anomaly detection (TTAD) method for hyperspectral images (HSIs) is proposed in this article. TTAD departs from the single analytical mode based on specific assumptions but directly parses the HSI data itself. It makes full use of the “few and different” characteristics of anomalous data points that are sparsely distributed and far away from high-density populations. On this basis, topology, a powerful tool in mathematics that successfully handle multiple types of data mining tasks, is applied to AD to ensure sufficient feature extraction of land covers. First, the redistribution of HSI data is realized by constructing a tree-type topological space to improve the separability between anomalies and backgrounds. Then, topologically related subsets in this space are utilized to evaluate the abnormality degree of each sample in a dataset, and detection results for the HSI are output accordingly. Abandoning traditional modeling but focusing on mining the data characteristics of HSI itself enables TTAD to better adapt to different complex scenes and locate anomalies with high precision. Experimental results on a large number of benchmark datasets demonstrate that TTAD could achieve excellent detection results with considerable computational efficiency. The proposed method exhibits superior comprehensive performance and is promising to be popularized in practical applications.
Ubuntu Linux Toolbox: 1000+ Commands for Ubuntu and Debian Power Users

In this handy, compact guide, youll explore a ton of powerful Ubuntu Linux commands while you learn to use Ubuntu Linux as the experts do: from the command line. Try out more than 1,000 commands to find and get software, monitor system health and security, and access network resources. Then, apply the skills you learn from this book to use and administer desktops and servers running Ubuntu, Debian, and KNOPPIX or any other Linux distribution.
Multi-body dynamics model of crawler wall-climbing robot

In this paper, a crawler-type wall-climbing robot with negative pressure adsorption is designed. The dynamic model of the robot is established based on the method of discretizing the force load of the track shoe. The correctness of the kinematic model and dynamic model is proved by comparing two different ways of virtual prototype simulation and prototype experiment. According to the simulation results of the dynamic model and virtual prototype, the influence of design parameters on the motion performance of the wall-climbing robot is analyzed. The smaller the speed difference between the two tracks of the robot, the longer the gauge between the two tracks, and the greater the inclination of the adsorption wall, the larger the turning radius of the robot will be. The research content based on this paper can provide a new design optimization method and theoretical basis for improving crawler wall-climbing robots and crawler vehicles.
Optical properties of cometary dust

Abstract : Cometary dust is observed in a variety of ways: scattered light, thermal emission, stellar occultations, dust coma and tail morphology, radar echos, and meteors associated with comets. To interpret these observations with respect to the physical parameters of the dust (size, shape, composition) and the properties of the dust emitting region, the physics of how electromagnetic radiation interacts with small particles must be understood. To understand the interaction of electromagnetic radiation with matter, the measurement and interpretation of optical constants of bulk materials must be understood Classically, a material can be approximated by a series collection of bound charges with a number of resonant frequencies. The optical constants (index of refraction or dielectric constant) of a material are a measure of the ability of the material to vibrate in response to an incoming electromagnetic wave. The laboratory measurement of optical constants is very difficult, and many published optical constants may be in error. Care must be taken in choosing a set of optical constants which best represent the material being used for modelling cometary dust. Scattering theory is usually synonymous with Mie theory, although Mie theory pertains only to spherical particles. In many cases spheres may be good approximations to the particles in the coma, but an understanding of non-spherical scattering effects is essential to determine the limitations of the spherical approximation. A variety of methods exist which, although computationally intensive, provide insight into shape effects.
Stable and Fast Planar Jumping Control Design for a Compliant One-Legged Robot

Compliant bipedal robots demonstrate a potential for impact resistance and high energy efficiency through the introduction of compliant elements. However, it also adds to the difficulty of stable control of the robot. To motivate the control strategies of compliant bipedal robots, this work presents an improved control strategy for the stable and fast planar jumping of a compliant one-legged robot designed by the authors, which utilizes the concept of the virtual pendulum. The robot was modeled as an extended spring-loaded inverted pendulum (SLIP) model with non-negligible torso inertia, leg inertia, and leg damping. To enable the robot to jump forward stably, a foot placement method was adopted, where due to the asymmetric feature of the extended SLIP model, a variable time coefficient and an integral term with respect to the forward speed tracking error were introduced to the method to accurately track a given forward speed. An energy-based leg rest length regulation method was used to compensate for the energy dissipation due to leg damping, where an integral term, regarding jumping height tracking error, was introduced to accurately track a given jumping height. Numerical simulations were conducted to validate the effectiveness of the proposed control strategy. Results show that stable and fast jumping of compliant one-legged robots could be achieved, and the desired forward speed and jumping height could also be accurately tracked. In addition to that, using the proposed control strategy, the robust jumping performance of the robot could be observed in the presence of disturbances from state variables or uneven terrain.
On Writing the History of Special Relativity

Nearly all accounts of the genesis of special relativity unhesitatingly assume that the theory was worked out in a roughly five week period following the discovery of the relativity of simultaneity. Not only is there no direct evidence for this common presupposition, there are numerous considerations which militate against it. The evidence suggests it is far more reasonable that Einstein was already in possession of the Lorentz and field transformations, that he had applied these to the dynamics of the electron, and that portions of the 1905 paper had actually been drafted well before the epistemological analysis of time.
Profiles of emission lines in active galactic nuclei - III. Observations of Ha, [N II] and [S II] profiles

High-resolution (FWHM= 28 km s-1) observations of Ha, [N II] λ6548/6583 and [S II] λ6717/6731 emission lines in several southern active galactic nuclei (AGN) are presented. Deblending of the Hα + [N II] profiles was performed using, when available, the [0 III] λ5007 profile shape as a template. Line profile measurements, as well as line intensities, are tabulated. We found to be relatively common among the observed objects the existence of structure in the line cores, pointing to the complexity of the dynamics in the low-velocity emission region. Differences in profile shape and width amongst different lines are also common, indicating that often there is a superposition, on the spectrograph slit, of emission regions with different dynamics and excitation conditions. This superposition is quantified in the case of IC 5063. We found weak, broad Ha emission in IC 5063 and IC 5135. In NGC 2992, we were unable to confirm the presence of a broad Ha component with the same intensity as found by previous authors, which we ascribe to spectral resolution effects.