bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient and Robust Estimation of GARCH Models
Authors: Jiang X. , Song X. , Xiong Z. 
Published: December 2015

Abstract
Generalized autoregressive conditional heteroscedastic (GARCH) models have been a powerful tool for modeling volatility. In this paper, we propose an efficient and robust method for estimating the parameters of GARCH models. This method involves a sequence of weights and takes a data-driven weighting scheme to maximize the asymptotic efficiency of the estimators. Under regularity conditions, we establish asymptotic distributions of the proposed estimators for a variety of heavy- or light-tailed error distributions. Simulations endorse our theoretical results. Our approach is applied to analyze the S&P 500 Composite index in the U.S. financial market and run some regression diagnostics to validate the fitted model.
Evaluating Airbag Safety Vests for Equestrian Sports
Authors: Ade N. , Stämpfli R. , Schmitt K. -U. 
Published: December 2015

Abstract
Thoracic injuries are common in equestrian sports. Advanced safety equipment, including airbag vests, have been introduced to the market to protect this body region. Standard EN13158 [“Protective Clothing—Protective Jackets, Body and Shoulder Protectors for Equestrian Use: For Horse Riders and Those Working with Horses, and for Horse Drivers—Requirements and Test Methods,” European Committee for Standardization, Brussels, 2009 (in German)] defines the minimum requirements for conventional safety vests; however, there is currently no standard related to airbag vests for equestrian sports. The aim of this study is to investigate the applicability of a draft motorcycling standard [prEN1621-4, “Motorcyclists' Protective Clothing Against Mechanical Impact. Part 4: Motorcyclists' Inflatable Protectors—Requirements and Test Methods,” Deutsches Institut für Normung e.V., Berlin, 2010 (in German)] for equestrian airbag vests. Based on EN13158 and prEN1621-4, airbag vests for equestrian sports were tested. In addition to the tests outlined in the above standards, the pressure induced by the inflating airbag on the thorax was measured and the sound level of the deploying airbag was recorded. The use of airbag vests in conjunction with conventional vests was also investigated. Testing airbag vests in accordance with the existing standards was possible without practical issues. The impact tests indicated that airbag vests were able to absorb higher forces compared to conventional vests. The airbag inflation times were recorded to be between 186 and 260 ms. Trigger forces were measured to be between 150 and 593 N. The maximum pressure on the upper body resulted in 20 to 84 kPa. The bang associated with airbag deployment generated a sound level of 87.3 to 98.4 dB(A). The degree of protection offered by airbag vests was demonstrated by applying the procedures prescribed in existing standards. The draft standard for motorcycling proved to be applicable to equestrian sports. However, regarding the interpretation of the test results, it seems necessary to adapt several threshold values of this standard to account for equestrian-specific parameters.
Test Method to Assess Membrane Layer Fatigue Response on Orthotropic Steel Bridge Decks
Authors: Liu X. , Tzimiris G. , Li J. , Scarpas A. 
Published: December 2015

Abstract
In order to adequately characterize the fatigue response of the various membranes with surrounding multilayer surfacing layers on orthotropic steel decks and collect the necessary parameters for FE modeling, the details of the cyclic membrane adhesion tester (MAT) were introduced. The fatigue damage in membrane interface was related to the amount of dissipated work computed by using the measurement of actuator load and piston deformation during the loading cycle. The dissipated work, which is equivalent to the lost part of the total potential energy of the membrane, was utilized to explain the incremental damage during the testing. Furthermore, using the experimental data obtained from MAT, ranking of the bonding characteristics of various membrane products was demonstrated as well as the role of other influencing factors, such as the types of substrate and test temperatures.
Variable Limits and Control Charts Based on the Half Normal Distribution
Authors: Srinivasa Rao B. , Srinivasa Kumar C. , Rosaiah K. 
Published: December 2015

Abstract
The well-known variable control charts for mean and range of sub-groups for the half normal distribution were constructed by three different approaches. One from the first principles of using percentiles of the sampling distribution of the sample mean and sample range, the second from Shewhart control limits, and the third approach was a skewness correction procedure depending on the skewness coefficient. The coverage probabilities of the three different approaches were computed through simulation and compared.
High Spatial Resolution EDS Mapping of Nanoparticles at Low Accelerating Voltage
Authors: Liu Z. W. , Sun C. , Gauvin R. , Wu W. , Zeng Y. , Demers H. 
Published: December 2015

Abstract
In conventional energy-dispersive spectroscopy/scanning-electron microscopy (EDS/SEM) analysis, the pear-shaped interaction volume of incident electrons in the bulk sample determines spatial resolution and the actual scope of EDS analysis is usually a few cubic microns. Lowering the accelerating voltage can reduce effectively the interaction volume of the electron beam. In this study, Monte Carlo (MC) simulation was used to analyze effectively the actual interaction between low-energy incident electrons and nanoparticles. MC x ray, a new Monte Carlo program, was used to further simulate EDS mapping of Ni nanoparticles on the top of an Al2O3 matrix at an accelerating voltage of 3 kV, and the theoretical spatial resolution was calculated to be approximately 10 nm. In addition, EDS mapping images of 17-nm Ni nanoparticles were successfully acquired at high spatial resolution similar to the theoretical value by adjusting the operating conditions for SEM-EDS analysis, including the use of immersion objective lens, the removal of electron trap and collimator, and the reduction of working distance as well as detector distance.
Online Measurement of Alcohol Concentration Based on Radio-Frequency Identification
Authors: Yu Yinshan , Yu Xiaolei , Zhao Zhimin , Liu Jialing , Wang Donghua 
Published: December 2015

Abstract
This paper presents a method for online measuring signal backscattering and reading distance from radio frequency identification (RFID) tags attached to the surface of the liquid, and for calculating the corresponding alcohol concentration. We derive a theoretical formula on the reading distance and received power. Subsequently, the former measurement values are converted to the corresponding alcohol concentration. Experiments are performed using an ISO/IEC 18046-based measurement system in the ultra high frequency (UHF) RFID band [ISO/IEC 18046, “Information Technology—Radio Frequency Identification Device Performance Test Methods,” International Organization for Standardization, London, 2007]. A fitted model of the relationship of alcohol concentration, reading distances, and received power is established. Based on the proposed fitted model, the processor can calculate alcohol concentration in aqueous solutions. The experimental data are compliant to the theoretical counterparts. This online method could be applied to dynamic measurement in automatic assembly line and has the advantages of excellent versatility, high measuring accuracy, stable performance, and quick response speed.
Assessment of Surface Quality of Stone Treated by Water Jet and Bush Hammering Using Geostatistical Simulations
Authors: Ozcelik Y. , Tercan A. E. , Yilmazkaya E. 
Published: December 2015

Abstract
A number of surface-treatment methods can be used to increase the rock roughness to improve its antislip properties while preserving aesthetic appearance. Bush hammering and water jetting are two of these surface-treatment methods. In this study, Sardinian basalt samples were treated with plain water jet and soft and hard bush-hammering methods, and quality of surfaces treated was assessed geostatistically. Realizations of the treated surfaces were generated by using sequential Gaussian simulation. The results show that the surfaces treated by the water-jet method are more homogeneous than others.
Correlation of Global Quantities for Material Characterization by Sharp Indentation Testing of Elastoplastic Materials
Authors: Larsson Per-Lennart 
Published: December 2015

Abstract
Indentation problems pertinent to sharp indenters were examined. The analysis concerned classical elastic-plastic materials and, especially so, the details of the behavior of global contact quantities, such as mean contact pressure and the size of the contact area, in the transition region where elastic and plastic effects are of equal magnitude. The global contact quantities were correlated accurately using a single parameter, comprising both geometrical and mechanical properties, and presented using closed form expressions directly applicable to material characterization or measurements of residual mechanical fields by sharp indentation tests, but also for situations such as contact in gears or in electronic devices. The derived relations were based on highly accurate previous results from finite element studies of sharp indentation problems.
A Novel General Approach for Solving a Supplier Selection Problem
Authors: Chang Kuei-Hu , Chain Kai , Wen Ta-Chun , Yang Gino K. 
Published: December 2015

Abstract
Due to the progress of information technology and the era of globalization, supply chain management (SCM) is now the key activity to obtaining and maintaining the competitive advantage of firms in the global competitive environment. In order to maximize total supply chain profitability, supplier selection plays a very important role in supply chain management. However, the supplier selection process is a complex multiple-criteria decision making (MCDM) problem where both qualitative and quantitative aspects need to be considered. Moreover, there are many unknown, partly known, missing, or inexistent data in the process of collecting data from the supplier selection, increasing the difficulty of supplier selection. It cannot be fully solved by the traditional analytical hierarchy process (AHP) method. Therefore, this study integrated the AHP and the soft set approach for solving the supplier selection problem. The advantage of this proposed method in research is that it has not lost any expertise in providing useful information. A numerical example of the application was also presented. This study compared the results with the traditional AHP method for dealing with incomplete data. The results of the comparison showed that the approaches presented in this paper are preferable in terms of reflecting practical feasibility.
Comparing Raindrop Size and Velocity Measurement Accuracy Using Shadowgraphy, Disdrometery, and Pie Pan Measurement Techniques
Authors: Tullis Blake P. 
Published: December 2015

Abstract
Local raindrop size and velocity data measurements are often used to quantify hyetographs for rainfall events; the accuracy of the rainfall hyetograph is dependent on the accuracy of the raindrop size and velocity measurement technique. Different raindrop size and velocity measurement techniques were evaluated using simulated raindrops of relatively uniform size in the laboratory. The measurement techniques included a high-speed photography-based imaging system (shadowgraphy), an optical disdrometer, and a pie pan method (raindrop size only). The shadowgraphy system, which had a measurement uncertainty of 2.86 %, served as the comparative standard for the other measurement techniques. The disdrometer raindrop size measurements were relatively accurate except for raindrops passing near the lateral limits of the measurement sheet; the peripheral raindrops sizes were estimated to be 97 % smaller than their actual size. The pie pan method overestimated raindrop sizes by approximately 41 %. The disdrometer raindrop velocity data underestimated actual velocities. Of the techniques evaluated, the disdrometer represents the only practical field deployable method for quantifying rainfall data.
Simulation of the Quasi-Static Uniaxial Compressive Behavior of Entangled Titanium Wire Materials (ETWMs)
Authors: Liu Ping , Qiao Yongmin , Zhao Qinghua , Wu Minchang , Li Jipeng 
Published: December 2015

Abstract
A method combining the Voronoi random model with ABAQUS finite element software was employed to simulate the deformation process of entangled titanium wire materials with different porosities under the quasi-static uniaxial compression load, and investigate the deformation mechanism of the materials. The results revealed that the non-uniform density distribution could cause the local deformation and the formation of deformation regions. The model almost did not appear as macroscopic fracture until the final failure. The entangled titanium wire materials models showed typical elastic-plastic behavior under compression load (i.e., three stages of deformation): an elastic stage, a relatively longer plastic collapse platform stage, and a densification stage. It was also found that the “platform stage” in the stress-strain curve during the compression process was not very flat. The length of the platform stage became shorter as porosity decreased, and the plateau compression force increased significantly with the decrease of porosity. These results agreed with the actual compression test results of the entangled titanium wire materials.
A New Family of Quadratic Hazard Rate-Geometric Distributions With Reliability Applications
Authors: Okasha Hassan M. , Kayid M. , Abouammoh M. A. , Elbatal I. 
Published: December 2015

Abstract
This paper introduced the generalized quadratic hazard rate distribution. This new distribution generalizes several well-known distributions such as generalized exponential, generalized Rayleigh, and generalized linear hazard rate. Some statistical and reliability properties of the new distribution were discussed. The maximum likelihood estimates of its unknown parameters were obtained by simulation. The proposed model and other derived results were utilized for fitting real data set and it was shown that the new distribution provided a better fit than some other known distributions.
Evaluation and Comparison of Double Clip Gauge Method and Delta 5 Method for CTOD Measurement in SE(T) Specimens
Authors: Van Minnebruggen Koen , Verstraete Matthias , Hertelé Stijn , De Waele Wim 
Published: December 2015

Abstract
The experimental evaluation of the fracture toughness of line pipe steels and girth welds is increasingly performed through single edge notched tensile—SE(T)—testing. The notch constraint in these specimens closely matches that in pipes. This paper focused on the measurement of the crack tip opening displacement (CTOD). The double clip gauge method and the GKSS δ5 method were compared based on experimental tests on both welded and nonwelded specimens. A good correspondence between both techniques was observed. The δ5 method tended to result in a slightly lower estimation of crack driving force, which was explained by the difference between both CTOD definitions. Both techniques were concluded to be equivalent for the evaluation of CTOD in SE(T) specimens.
Calculation Method and Influence Law of Pavement Rut Under Dynamic Load
Authors: Li Limin , He Zhaoyi , Jiang Jianqing , Lei Ting 
Published: December 2015

Abstract
Based on vehicle dynamic loading, the rut calculation method is put forward, the influence law of pavement rut is obtained, and the rutting prediction for the test road was performed by employing this method. The results indicated that there is little difference between calculated rutting value and the real one of the test roads, and the maximum error is 9 %. Moreover, their deformation shapes of rutting are almost the same as a whole. Therefore, the proposed rutting calculation method is feasible for the very complex problem of rutting calculation. The influence law of pavement rut under dynamic load was studied by using this method. The results showed that high temperature, heavy load, and slow speed have important effects on rutting damage of asphalt pavement. Under heavy loads, with the temperature higher than 50°C, the repetition times of axle load more than 106, and the tire pressure higher than 0.9 MPa, the rutting depth of pavement will increase dramatically. In addition, when the vehicle velocity is smaller than 40 km/h, the rutting depth of pavement will also increase obviously with the loading duration increasing (i.e., with the vehicle velocity reducing). At the early stage of the loading process, the rutting depth of pavement increases rapidly, and as the loading time passes by, the growth rate of rutting depth gradually slows down, and finally rutting depth approaches to a fixed value. Furthermore, high modulus asphalt concrete applied in the middle course can significantly enhance the anti-rutting performance of asphalt pavement, and the anti-rutting ability of asphalt pavement can also be improved by increasing the thickness of the semi-rigid bottom layer of the base and of the surface course properly, especially of the upper layer of the surface course.
Test and Evaluation for Bonding Property Between GFRP and Concrete
Authors: Gu Xingyu , Dai Yiqing , Jiang Jiwang 
Published: December 2015

Abstract
Glass fiber reinforced polymer (GFRP) composite is applied widely in continuously reinforced concrete pavement (CRCP) because of its prominent advantages in properties and cost compared with conventional steel materials. This paper investigated influences of concrete strength, embedded depth, surface form, and diameter of bars on the GFRP-concrete bond performance by a series of pull-out tests. A finite element model was built to simulate the whole pull-out process. The test results showed that, within a certain range, rib depth has a positive effect on both slip control and stress improvement. Smaller rib spacing had a positive effect on controlling the slip displacement, but the diameter of bars and concrete strength had a negligible impact on both the bond strength and slip displacement. The developed finite element model (FEM) could provide similar results as the pull-out tests, and the model also demonstrated a distinct peak value in a shear stress cloud chart. Meanwhile, in order to analyze the effect of embedded depth on bond strength, a normal distribution model was utilized to fit the shear stress distribution. The analysis results retrieved from the normal distribution model, with an extreme small relative error less than 4 %, were more in line with the experimental results than the traditional average distribution model.
Road Landscape Space Enclosure Scale and Sequence Characteristics Based on Human Aesthetic Perception and Psychological Experience
Authors: Qin Xiaochun , Gao Liang , Shen Yupeng 
Published: December 2015

Abstract
Road landscape environments are defined in terms of road space, consisting of the pavement and the surrounding boundaries, and the various road landscape elements normally constitute the component parts of road space. The creation and organization of spatial interfaces in road landscape planning not only play an important role in transportation function planning but also create different landscape spatial atmospheres, which largely determine the space perception and psychological experience of the passengers when traveling on the road. The major constituent elements of road spatial interfaces were defined in this paper, and the conception and quantized calculation method of road space enclosure scale was proposed. The spatial characteristics and the different spatial feelings of the road solid interface, void interface, and zero interface were analyzed in detail. The quantitative relationship between space enclosure scale and people's spatial experience was established based on the solid interface of plain, cutting, and filling areas, the void interface of roadside trees, and the zero interface of filling areas and viaducts. The spatial form of road landscape environment was summarized in flat, wave, and climax types according to the arrangement and layout of landscape space sequences, and the spatial sequence characteristics and improvement means for original space were discussed. Taking Guangwu Road in the Guangdong Province in the rolling hill area of South China as the case study, the road space interface enclosure map was drawn, and the road landscape space types were analyzed according to cutting and filling conditions by employing the road design software HintCAD, which provided the primary quantitative reference for road space sequence planning and regional landscape style control to make road landscape planning fully integrated with people's aesthetic psychology and dynamic visual features.
Comparison Between Superplastic and Non-Superplastic Grade AA 5083
Authors: Giuliano G. , Samani F. 
Published: December 2015

Abstract
To analyze the hot-deformation behavior of aluminum alloy 5083, this work shows the results of free-forming tests at constant pressure in different pressure and temperature conditions. Results of the non-superplastic AA5083 are compared with results obtained with the same material but in superplastic conditions. Though formability is quite reduced in non-superplastic grade aluminum alloy 5083, the hot-deformation process is able to reduce operating temperature and time of final forming if forming pressure is increased.
Testing Methods on Ceramic Rolling Elements for Hybrid Bearings
Authors: Schöppl Oskar , Lube Tanja 
Published: December 2015

Abstract
Different manufacturing routes for ceramic balls and rollers used in hybrid bearings can lead to different microstructures and mechanical properties of a silicon nitride grade, even being delivered by one supplier. This fact, experienced by the authors, makes it necessary to do testing on the different balls or rollers themselves. This will make sure that the minimum properties on strength, fracture toughness, and microstructure requirements according to ASTM F2094/F2094M-14 and ISO 26602 are fulfilled on the bearing component and not only on special bar samples prepared for bending tests. A first approach done in the bearing industry was a simple crush test of two or three balls on top of each other. This gave a very rough estimate of a “static load rating.” The material resistance to cracks and Hertzian contact damage was tested by indentations with tungsten carbide spheres or doing impact strength testing. A first approach for “real” strength measurement of ceramic spheres was introduced by using a diametrally compressed “C-Sphere” specimen. This was further developed to be more easily machinable and was simply called “Notched ball test.” A similar test was also developed in recent times for ceramic cylindrical roller rollers, called the “Notched roller test.” The goal of this paper was to discuss and summarize test methods for strength and combinations of strength with other properties or effects like toughness and/or residual stresses for ceramic rolling elements that have been established so far for hybrid bearings. This supported the understanding for the need to establish the notched ball test, which was already established as a National Standard ÖNORM M6341:2013 in Austria, and also in ISO and ASTM.