Miracle-dz/UniFAR-FTUs huggingface dataset:
Sensitivity Analysis of Turbine Fatigue and Ultimate Loads to Wind and Wake Characteristics in a Small Wind Farm

Abstract. Wind turbines are designed using a set of simulations to determine the fatigue and ultimate loads, typically focused solely on unwaked wind turbine operation. These structural loads can be significantly influenced by the wind inflow conditions. When placed in the wake of upstream turbines, turbines experience altered inflow conditions, which can additionally influence the fatigue and ultimate loads. Although significant research and effort has been put into measuring and defining such parameters, limited work has been done to quantify the sensitivity of structural loads to the inevitable uncertainty in these inflow conditions, especially in a wind farm setting with waked conditions. It is therefore important to understand the impact such uncertainties have on the resulting loads of both non-waked and waked turbines. The goal of this work is to assess which wind-inflow- and wake-related parameters have the greatest influence on fatigue and ultimate loads during normal operation for turbines in a three-turbine wind farm. Twenty-eight wind inflow and wake parameters were screened using an elementary effects sensitivity analysis approach to identify the parameters that lead to the largest variation in the fatigue and ultimate loads of each turbine. This study was performed using the National Renewable Energy Laboratory 5 MW baseline wind turbine with synthetically generated inflow based on the International Electrotechnical Commission (IEC) Kaimal turbulence spectrum with IEC exponential coherence model. The focus was on sensitivity to individual parameters, though interactions between parameters were considered, and how sensitivity differs between waked and non-waked turbines. The results of this work show that for both waked and non-waked turbines, ambient turbulence in the primary wind direction and shear were the most sensitive parameters for turbine fatigue and ultimate loads. Secondary parameters of importance for all turbines were identified as yaw misalignment, u-direction integral length, and the exponent and u components of the IEC coherence model. The tertiary parameters of importance differ between waked and non-waked turbines. Tertiary effects account for up to 9.0 % of the significant events for waked turbine ultimate loads and include veer; non-streamwise components of the IEC coherence model; Reynolds stresses; wind direction; air density; and several wake calibration parameters. For fatigue loads, tertiary effects account for up to 5.4 % of the significant events and include vertical turbulence standard deviation; lateral and vertical wind integral lengths; lateral and vertical wind components of the IEC coherence model; Reynolds stresses; wind direction; and all wake calibration parameters. This information shows the increased importance of non-streamwise wind components and wake parameters in fatigue and ultimate load sensitivity of downstream turbines.
Prevalence characteristics of cervical human papillomavirus genotypes in Nanning, China: A 10‐year survey of 77,756 women from one medical center

The prevalence of human papillomavirus (HPV) infection and HPV genotypes varies in different regions. However, there is little data on HPV prevalence and genotyping in Guangxi Province, South China. This study conducted a 10‐year survey in a health center, to estimate the prevalence characteristics of HPV genotypes.
Trust Management Systems in Cloud Services Environment: Taxonomy of Reputation Attacks and Defense Mechanisms

Using cloud data storage, large amounts of data can be stored by data owners in a flexible way and at low cost. Hence, there has been a major increase in online cloud service providers and their users. The privacy and security of data in the cloud computing environment is a major issue. Data privacy can be ensured by using a cryptographic access control method, so that data can only be accessed by authorized customers while keeping it inaccessible to unauthorized users. However, this type of cryptographic approach does not address the issue of trust. An integration between several trust models and cryptographic access control models has been presented in many research papers, the aim of which is to make data stored in cloud storage systems more secure. The objective of this study is to determine a solution that can suitably handle trust issues in access control models to decrease the risk as greater security to cloud storage systems, and the quality of decisions being made by data owners and cloud operators is improved. In this paper, we have presented a taxonomy for trust criteria and reputation attacks in cloud computing. Also, some of the fundamental concepts regarding trust management of services within cloud environments have been presented in this paper, along with the latest technologies. There are three layers in the model, and a series of dimensions are further determined for every layer (which are the assessment criteria), which serve as the benchmark to evaluate many research prototypes of trust models in a cloud computing environment by comparing these criteria when evaluating several trust models in a cloud computing environment. In this paper, a comparison of fifteen representative trust management research samples in cloud computing and the appropriate research domains were also carried out by employing this analytical model.
Capitalization Effects of Rail Transit and Bus Rapid Transit on Residential Property Values in a Booming Economy

This research investigated the capitalization effects of proximity to rail transit and bus rapid transit (BRT) in fast-growing Beijing. Few related studies have been conducted for Chinese cities because the real estate market has only recently been established. Data were collected on apartment homes sold in the Beijing metropolitan area during 2011, and hedonic price modeling was employed to gauge the price premiums or discounts associated with proximity to transit stations. Overall, the authors identified an average price premium of around 5% for properties near rail transit stations, but no statistically significant effects were detected at BRT station areas. Moreover, the authors found that station proximity effects increased both in magnitude and spatial extent at stations located farther from the city center and those surrounded by low- and middle-income neighborhoods. For example, the price premium was as high as 10% in some suburban and low-income areas. The conclusion drawn was that rail transit investment was an effective strategy for Beijing to reshape its urban spatial structure, and local governments in China might consider a rail and property development model as a financing solution for rail transit investment. This study contributes to the evidence of capitalization effects of public transit from a booming and transitional economy.
Optimal Capacitor Placement for Unbalanced Distribution System using Graph Theory

In this paper, a graph theory-based allocation methodology of capacitor bank is proposed for unbalanced distribution system. A single-stage optimization procedure using electrical centrality measure concept to identify the best suitable locations for the multi-point connection of capacitor is described with its significance. The electrical centrality measure approach gives ranking of all the buses, single capacitor or multiple capacitors can be placed in unbalanced distribution system (UDS) using these indices to fulfill the reactive power demand and maintain voltage profile of the system. To evaluate the performance of the UDS due to capacitor bank connection two parameters are considered – improvement of overall voltage profile and reduction of active power loss. The contribution of the paper is – first, electrical centrality measure is used for identifying the capacitor bank location in the unbalanced distribution system and second it optimizes the size of the capacitor using two different objectives to improve the system voltage profile and reduce the active power loss. The proposed methodology is tested on a modified 123 bus unbalanced distribution system. The active power loss reduction up to 16.50% and total voltage deviation reduction up to 71.53% were achieved using the proposed method. The obtained results corresponding to the two objectives are also compared.
Efficient performance optimisation of wireless power transmission using genetic algorithm

Wireless power transfer (WPT) systems using a coupled magnetic resonance have to overcome the frequency splitting phenomenon for a certain distance in order to achieve the best efficiency. In this reported work, a simple and effective method is demonstrated to overcome the frequency splitting for an optimal efficiency, regardless of the distance variation while maintaining the single desired operating frequency. Then, the systems do not need complicated frequency adjustment systems to track the split frequency. For the proposed method, the equivalent circuit parameters of the WPT system are extracted to overcome the frequency splitting by using the genetic algorithm (GA). Then, two adjustable capacitors are added at the source and the load with the optimal values calculated by the GA, again, at the desired operating frequency for the optimal efficiency.
A Non-Iterative Method for Factorization of Positive Matrix in Discrete Wavelet Transform Based Image Compression

A non-iterative method of factorizing a 4◊4 positiv e matrix, with the application to image compression is explained using an example. The procedure is applie d to all the 4096 number of 4◊4 pixel sub-blocks of a 256◊256 image for compression. The proposed compression technique can be applied to the Discrete Wavelet Transform (DWT) coefficients of the test image. The 16 Pixel Intensity Values (PIV) or their D WT coefficients of a 4◊4 pixels sub-block of the image can be represented by the outer product of a 4◊1 c olumn matrix and a 1◊4 row matrix, with Least Mean Square Error (LMSE) criterion. Hence, instead of transmitting the 16 PIVs or their DWT coefficients, the values of the 4 elements of the column matrix and the 4 elements of the row matrix alone are transmit ted resulting in a maximum compression ratio of 2 (16/4+4). The receiver can recreate the 4◊4 pixels sub-block or their DWT coefficients, by calculating the outer products of 4 values of column matrix with 4 values of row matrix. In case of DWT coefficients inverse DWT is applied to recreate the pixels. This principle is extended to all the sub-blocks of the 256◊256 image to compress and later reconstruct the image.
Revealing the influence of hyporheic water exchange on the composition and abundance of bottom-dwelling macroinvertebrates in a temperate lowland river

We studied distributions and abundances of macroinvertebrates in relation to hyporheic water exchange (HWE) patterns of the upper Biebrza − a small, lowland, low dynamic European river located in Northeast Poland. On a 6-km stretch of the river; we determined the variability of water exchange in the hyporheic zone by using direct field measurements of the pressure gradient to determine groundwater–surface water interactions. We identified locations with upwelling and downwelling fluxes of HWE as well as ambiguous hydraulic contact between groundwater and surface water along the river. In these locations, we sampled bottom-dwelling macroinvertebrates. In total, 627 individuals of benthic macroinvertebrates of 34 taxa were identified. We revealed that bottom-dwelling macroinvertebrate fauna is more abundant and diverse in river stretches where water from the river infiltrates the hyporheic zone. Results also show higher taxonomic richness and abundances of benthic macroinvertebrates in stretches with diagnosed infiltrating conditions (downwelling flux in a hyporheic zone) compared to in stretches where the river drained groundwater (upwelling flux in a hyporheic zone), but the recorded differences were not statistically significant.
MgrB dependent colistin resistance in Klebsiella pneumoniae is associated with an increase in host-to-host transmission

Due to its high transmissibility, Klebsiella pneumoniae (Kpn) is one of the leading causes of nosocomial infections. Here, we studied the biological cost of colistin resistance, an antibiotic of last resort, of this opportunistic pathogen using a murine model of gut colonization and transmission. Colistin resistance in Kpn is commonly the result of inactivation of the small regulatory protein MgrB. Without a functional MgrB, the two-component system PhoPQ is constitutively active, leading to increased lipid A modifications and subsequent colistin resistance. Using an engineered MgrB mutant, we observed that MgrB-dependent colistin resistance is not associated with a fitness defect during in vitro growth conditions. However, colistin-resistant Kpn colonizes the murine gut poorly, which may be due to the decreased production of capsular polysaccharide by the mutant. The colistin-resistant mutant of Kpn had increased survival outside the host when compared to the parental colistin-sensitive strain. We attribute this enhanced survivability to dysregulation of the PhoPQ two-component system and accumulation of the master stress regulator RpoS. The enhanced survival of the colistin resistant strain may be a key factor in the observed rapid host-to-host transmission in our model. Together, our data demonstrate that colistin-resistant Kpn experiences a biological cost in gastrointestinal colonization. However, this cost is mitigated by enhanced survival outside the host, increasing the risk of transmission. Additionally, it underscores the importance of considering the entire life cycle of a pathogen to truly determine the biological cost associated with antibiotic resistance. Importance The biological cost associated with colistin resistance in Klebsiella pneumoniae (Kpn) was examined using a murine model of Kpn gut colonization and fecal-oral transmission. A common mutation resulting in colistin resistance in Kpn is a loss-of-function mutation of the small regulatory protein MgrB that regulates the two-component system PhoPQ. Even though colistin resistance in Kpn comes with a fitness defect in gut colonization, it increases bacterial survival outside the host enabling it to more effectively transmit to a new host. The enhanced survival is dependent upon the accumulation of RpoS and dysregulation of the PhoPQ. Hence, our study expands our understanding of the underlying molecular mechanism contributing to the transmission of colistin-resistant Kpn.
Six-axis capacitive force/torque sensor based on dielectric elastomer

The six axis F/T sensor is a primary component for the robotic technologies, but its high unit cost hampers the popularization to the robotic applications. In this paper, we present a six-axis force-torque capacitive sensor based on dielectric elastomer. Dielectric elastomer is compressed and deformed with external forces acting on it. Its deformation results in the variation of capacitance, which can be used as a kind of capacitive sensing scheme. The proposed sensor consists of plastic structure and dielectric elastomer capacitors. Since it takes a simple structure, it is possible to fabricate by using a plastic molding process, which results in extremely lower cost than existing off-the-shelf products. We present the basic structure and design of the sensor with the explanation of its working principle. A fabrication method dedicated to the sensor is developed and finally, a prototype will be demonstrated with calibration procedures.
Evaluation of Laboratory, Construction, and Performance Variability by Bootstrapping and Monte Carlo Methods for Rutting Performance Prediction of Heavy Vehicle Simulator Test Sections

This paper demonstrates an innovative reliability analysis approach for prediction of asphalt rutting performance. In this approach, reliability was evaluated by considering the variability in laboratory test results, layer thicknesses, stiffnesses, and measured in situ performance. The effects of input design parameters variability on predicted performance were determined using the calculated distributions of calibration coefficients. To assess the contribution of each input parameter’s precision to the precision of calculated calibration coefficients, various cases were created by including and excluding the variability in these parameters in the calibration process. These distributions were also used for rutting performance prediction and reliability evaluation of highway sections. In this way, rut depths for different reliability levels can be predicted without performing computationally intensive calculations within the design software. The results indicated that distributions of calibration coeffici.
Real-time pedestrian detection with the videos of car camera

Pedestrians in the vehicle path are in danger of being hit, thus causing severe injury to pedestrians and vehicle occupants. Therefore, real-time pedestrian detection with the video of vehicle-mounted camera is of great significance to vehicle–pedestrian collision warning and traffic safety of self-driving car. In this article, a real-time scheme was proposed based on integral channel features and graphics processing unit. The proposed method does not need to resize the input image. Moreover, the computationally expensive convolution of the detectors and the input image was converted into the dot product of two larger matrixes, which can be computed effectively using a graphics processing unit. The experiments showed that the proposed method could be employed to detect pedestrians in the video of car camera at 20+ frames per second with acceptable error rates. Thus, it can be applied in real-time detection tasks with the videos of car camera.
Wave propagation along a rectangular metallic waveguide longitudinally loaded with a metamaterial slab

Wave propagation along a rectangular metallic waveguide, loaded with a longitudinal metamaterial slab adjacent to air, is studied in this paper. The dispersion relations have been obtained and the β − ω diagrams have been drawn for various width ratios of the metamaterial to air regions. For real propagation coefficients, in the 0 < β < k0 range, the group velocity could be negative, very low or constant, depending on the frequency range and on the width ratios of the two regions. In some cases, it has been found that the propagation coefficient is complex although the media are lossless: there is no net energy flow through any cross section of the guide so that the energy present is only stored reactive energy, and this seems to be due to strong coupling processes occurring in the device. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 123–127, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20067
Phase Transition Analysis for Covariance-Based Massive Random Access With Massive MIMO

This paper considers a massive random access problem in which a large number of sporadically active devices wish to communicate with a base station (BS) equipped with massive multiple-input multiple-output (MIMO) antennas. Each device is preassigned a unique signature sequence, and the BS identifies the active devices by detecting which sequences are transmitted. This device activity detection problem can be formulated as a maximum likelihood estimation (MLE) problem for which the sample covariance matrix of the received signal is a sufficient statistic. The goal of this paper is to characterize the feasible set of problem parameters under which this covariance based approach is able to successfully recover the device activities in the massive MIMO regime. Through an analysis of the asymptotic behaviors of MLE via its associated Fisher information matrix, this paper derives a necessary and sufficient condition on the Fisher information matrix to ensure a vanishing probability of detection error as the number of antennas goes to infinity, based on which a numerical phase transition analysis is obtained. This condition is also examined from a perspective of covariance matching, which relates the phase transition analysis to a recently derived scaling law. Further, we provide a characterization of the distribution of the estimation error in MLE, based on which the error probabilities in device activity detection can be accurately predicted. Finally, this paper studies a random access scheme with joint device activity and data detection and analyzes its performance in a similar way.
Compact and Wideband Parallel-Strip 180° Hybrid Coupler with Arbitrary Power Division Ratios

This paper presents a class of wideband 180° hybrid (rat race) couplers implemented by parallel-strip line. By replacing the 270° arm of a conventional 180° hybrid coupler by a 90° arm with phase inverter, the bandwidth of the coupler is greatly enhanced and the total circuit size is reduced by almost half. Simple design formulas relating the characteristic impedance of the arms and power division ration are derived. To demonstrate the concept, four couplers with different power division ratios of 1, 2, 4, and 8 were designed, fabricated, and tested. <path id="x1D446" d="M457 488l-30 -3q-17 148 -131 148q-53 0 -84.5 -34.5t-31.5 -82.5q0 -42 25.5 -72t74.5 -62l33 -22q63 -42 95 -85t32 -102q0 -84 -67 -137t-163 -53q-58 0 -113 22t-70 43l-4 152l27 4q4 -32 15 -62.5t31 -59.5t53.5 -47t76.5 -18q56 0 92 35t36 96q0 39 -25 70t-78 68 l-31 22q-32 23 -53.5 41.5t-45 57t-23.5 77.5q0 82 58 132.5t156 50.5q46 0 101 -17l18.5 -6t17 -6t8.5 -3q-4 -55 0 -147z" /> -parameters of the coupler are simulated and measured with good agreement. All working prototypes operate more than 112% impedance bandwidth with more than 25 dB port-to-port isolation and less than 5° absolute phase imbalance. The proposed 180° hybrid couplers can be employed as a wideband in-phase/differential power divider/combiner, which are essential for many RF and microwave subsystem designs.
Long term rainfall trend over meteorological sub divisions and districts of India

In this paper the long term trend of annual and seasonal rainfall over different districts, Meteorological (Met.) sub-divisions and whole India have been studied using the long term rainfall data for the period from 1901 to 2013. The changes in amount and pattern of rainfall have a significant impact on agriculture, water resources management and overall economy of the country. Mann-Kendall test is applied to check the significance of the trend. Linear Regression and Theil-Sen’s non parametric test has been applied to estimate the trend. The study is carried out for 632 districts and 34 sub divisions of India by utilizing the gridded rainfall data (0.25° × 0.25°) over the main land except Andaman & Nicobar and Lakshadweep islands. Many authors have studied that extreme events are increasing but there is no trend in Pan India’s rainfall. It is observed from the annual rainfall analysis 10% of the number of districts are showing significant increasing trend and 13% significant decreasing (mainly in Uttar Pradesh) trend whereas irrespective of high and low rainfall regions, 10% area of the country is showing significant increasing trend and 8% of the area of the country showing significant decreasing trend in annual rainfall. In Meteorological Sub divisions, east & west UP are showing significant negative trend and some of the coastal sub divisions are showing positive trend. It is also observed that the country’s rainfall is not showing any trend.