Search

• S tability and regularity analysis of bare footprint measurements at different motion speeds. • Significant differences were found in length measurements (A1-A5). • MPJ and Calc width showed no significant differences across different speeds. • Mean length measurements decreased gradually as walking speed accelerated among young adults in eastern China. In some crime scenes, there may be bare footprints. Analyzing and testing the linear measurements of bare footprints in crime scenes can play an important role in personal analysis and individual identification. However, the linear measurements of bare footprints may be influenced by different motion states, leading to changes in length and width or even significant deviations. Previous studies focused on the linear differences between static and dynamic footprints, and failed to take the speed factor into consideration. This paper studied the stability and change regularities of the linear measurements of bare footprints in four different motion states: standing, normal walking, fast walking and trotting. Dust footprints of the right feet were collected from 80 healthy young adults under these four motion states. Seven linear measurements were obtained for each footprint using the Reel method, totaling 2240 data sets. One-way repeated measures ANOVA was used to assess the measurement variations across the four states. The results showed that there were statistically significant variances in the length measurements (A1-A5) between the standing state and other motion states, whereas no statistically significant variances were observed between the three dynamic states. It was found that the mean values of the five length measurements (A1–A5) increased from static to dynamic state, and then gradually decreased slightly as the walking speed increased. Additionally, no significant differences were found in the two width measurements (MPJ Width and Calc Width) between the four motion states. As a preliminary study, this study can provide a reference for the analysis of bare footprints in different motion states extracted from crime scenes. [ABSTRACT FROM AUTHOR]

An on-the-go infield machine vision system was developed to measure internode length (i.e., the distance between main stem nodes) of cotton (Gossypium hirsutum L.) plants, which is a significant indicator of past water stress. An infield vehicle was developed to convey the machine vision system automatically across the crop canopy. This paper presents an evaluation of the devised system under a range of operational and field conditions. On average, the vision system's internode length detection rate ranged from 12 measurements per 100 plants for compact plants when the sun was directly overhead with respect to the camera, to 64 measurements per 100 plants for vigorous plants when the sunlight was perpendicular to the camera view angle. Imaging at night time using 850 nm near-infrared illumination resulted in internode length detection rates not significantly different from the most reliable daylight conditions. Both across-row and along-row operations of the system were evaluated, with the system yielding internode length measurements for groundspeeds up to 0.20 m/s for along-row operation. Visual occlusion of the main stem nodes by foliage and variations in natural lighting conditions were observed to be the principal reasons for internode lengths not being detected successfully for every plant. However, from the success rates observed, it is concluded that the system has the practical capability to map internode length across a field and hence, identify spatial trends in internode length from which trends in plant water stress can be inferred. [ABSTRACT FROM AUTHOR]

Copyright of Paradigma is the property of Universidad Pedagogica Experimental Libertador and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The focus of this paper is in Q-Lasso introduced in Alghamdi et al. (2013) which extended the Lasso by Tibshirani (1996). The closed convex subset Q belonging in a Euclideanm-space, form IN, is the set of errors when linear measurements are taken to recover a signal/image via the Lasso. Based on a recent work by Wang (2013), we are interested in two new penalty methods for Q-Lasso relying on two types of difference of convex functions (DC for short) programming where the DC objective functions are the difference of l1 and lsq norms and the difference of l1 and lr norms with r > 1. By means of a generalized q-term shrinkage operator upon the special structure of lsq norm, we design a proximal gradient algorithm for handling the DC l1 -lsq model. Then, based on the majorization scheme, we develop a majorized penalty algorithm for the DC l1 -lr model. The convergence results of our new algorithms are presented as well. We would like to emphasize that extensive simulation results in the case Q ? fbg show that these two new algorithms offer improved signal recovery performance and require reduced computational effort relative to state-of-the-art l1 and lp (p0; 1) models, see Wang (2013). We also devise two DC Algorithms on the spirit of a paper where exact DC representation of the cardinality constraint is investigated and which also used the largest-q norm of lsq and presented numerical results that show the efficiency of our DC Algorithm in comparison with other methods using other penalty terms in the context of quadratic programing, see Jun-ya et al. (2017). [ABSTRACT FROM AUTHOR]

The use of three-dimensional (3D) optical instruments to measure soft tissue facial characteristics is increasing, but systematic assessments of their reliability, practical use in research and clinics, outcome measurements, and advantages and limitations are not fully established. Therefore, a review of the current literature was performed on the reliability of facial anthropometric measurements obtained by 3D optical facial reproductions as compared to conventional anthropometry or other optical devices. The systematic literature search was conducted in electronic databases following the PRISMA guidelines (PROSPERO registration: CRD42018085473). Overall, 815 studies were identified, with 27 final papers included. Two meta-analyses were conducted. Tested devices included conventional cameras, laser scanning, stereophotogrammetry, and structured light. Studies measured living people or inanimate objects. Overall, the optical devices were considered reliable for the measurement of linear distances. Some caution is needed for surface assessments. All instruments are suitable for the analysis of inanimate objects, but fast scan devices should be preferred for living subjects to avoid motion artefacts in the orbital and nasolabial areas. Prior facial landmarking is suggested to improve measurement accuracy. Practical needs and economic means should direct the choice of the most appropriate instrument. Considering the increasing interest in surface-to-surface measurements, fast scan devices should be preferred, and dedicated protocols devised. [ABSTRACT FROM AUTHOR]

Dimensional measurements play a central role in enabling advanced manufacturing technologies, enhancing the quality of products and increasing productivity. This role becomes even more important in the context of Industry 4.0, where reliable and accurate digital models of products, processes and production systems are needed. To establish the traceability chain that links measurements in production to the length unit, dimensional artefacts – ranging from measurement standards to calibrated workpieces – are fundamental. The paper examines dimensional artefacts, discussing their characteristics, availability and role in supporting production by establishing metrological traceability, and provides guidelines for their selection, use and development. [ABSTRACT FROM AUTHOR]

Massive computation of the reconstruction algorithm for compressive sensing (CS) has been a major concern for its real‐time application. In this paper, we propose a novel high‐speed architecture for the orthogonal matching pursuit (OMP) algorithm, which is the most frequently used to reconstruct compressively sensed signals. The proposed design offers a very high throughput and includes an innovative pipeline architecture and scheduling algorithm. Least‐squares problem solving, which requires a huge amount of computations in the OMP, is implemented by using systolic arrays with four new processing elements. In addition, a distributed‐arithmetic‐based circuit for matrix multiplication is proposed to counterbalance the area overhead caused by the multi‐stage pipelining. The results of logic synthesis show that the proposed design reconstructs signals nearly 19 times faster while occupying an only 1.06 times larger area than the existing designs for N = 256, M = 64, and m = 16, where N is the number of the original samples, M is the length of the measurement vector, and m is the sparsity level of the signal. [ABSTRACT FROM AUTHOR]

To measure absolute length, the synthetic wavelength methods must construct a long enough synthetic wavelength made use of several single wavelengths, and make integer of the interference order be zero or a deterministic value. However, it is not easy to find corresponding wavelengths with appropriate values and high wavelength stability in practice. In this paper, a synthetic wavelength absolute measurement method was presented, adopting three high frequency stability lasers to form the synthetic wavelength chain. The measurement equations as well as the transition conditions between grades were derived. And a corresponding phase shift interference optical path was built to make high precision measurement for the absolute length value of the sample. The experiment and error analysis results show the measurement uncertainty is about 3 nm (a t 0. 3 m sample). In this method the requirement for initial measurement accuracy of the length is low and the measurement range is only limited by the length of the interferometric optical path. [ABSTRACT FROM AUTHOR]

Abstract In the present paper, we give some notes and counterexamples to show that the positive (semi) definite property of the Khatri-Rao and Tracy-Singh products of partitioned matrices are in general incorrect and show also that the matrix triangle inequality for the usual and Kronecker sums need not hold. Moreover, we show that the Fiedler's inequality as revisited by Johnson's works [10] cannot be strict. [ABSTRACT FROM AUTHOR]

This paper describes the potential of using flatbed scanners for a wide variety of dimensional measurements critical in the manufacturing of parts. A detailed example is presented on the measurement of thermoplastic spiral specimens. Some researchers use a spiral mold as a benchmark to assess the flow optimization of injection-molded thermoplastics. The spiral's length is critical in determining optimization algorithms that control the temperature, pressure, and speed of injection. This paper describes a new method developed for the precise measurement of these molded spiral lengths using a common flatbed scanner and AutoCAD software. The researchers compared measurements taken with a flatbed scanner to that of a profile projector through a gage repeatability and reproducibility (GR&R) study. Results of the study showed that flatbed scanners can be used to measure objects to an acceptable level of repeatability and reproducibility. [ABSTRACT FROM AUTHOR]

This paper explores the accuracy of Digital Elevation Models (DEMs), with particular reference to Australian published DEM5. Direct comparisons were made between cartometric and automatically measured photogrammetric DEMs at various grid spacings with an accurate and dense set of ground truth data. The cartometric DEMs were found to be more accurate than the photogrammetric DEMs for the small study site in this paper, with RMS errors in elevation of approximately 3.5 m and 4.5 m, respectively, and maximum absolute errors in elevation of approximately 12 m and 28 m, respectively. An important factor for environmental prediction studies is slope, and RMS errors in slope were approximately 6 percent and 20 percent for the cartometric and photogrammetric DEMs, respectively, with maximum absolute errors in slope of approximately 75 percent and 290 percent, respectively. However, use of suitable post- processing such as filtering may reduce the errors in photogrammetric DEMs to at least the same magnitude as cartometric DEMs. The cartometric DEMs were found to satisfy the USGS specifications for Level 2 data. [ABSTRACT FROM AUTHOR]

This is the first paper in a four-part series considering the fundamental question, "what does the word height really mean?" National Geodetic Survey (NGS) is embarking on a height modernization program in which, in the future, it will not be necessary for NGS to create new or maintain old orthometric height benchmarks. In their stead, NGS will publish measured ellipsoid heights and computed Helmert orthometric heights for survey markers. Consequently, practicing surveyors will soon be confronted with coping with these changes and the differences between these types of height. Indeed, although "height'" is a commonly used word, an exact definition of it can be difficult to find. These articles will explore the various meanings of height as used in surveying and geodesy and present a precise definition that is based on the physics of gravitational potential, along with current best practices for using survey-grade GPS equipment for height measurement. Our goal is to review these basic concepts so that surveyors can avoid potential pitfalls that may be created by the new NGS height control era. The first paper reviews reference ellipsoids and mean sea level datums. The second paper reviews the physics of heights culminating in a simple development of the geoid and explains why mean sea level stations are not all at the same orthometric height. The third paper introduces geopotential numbers and dynamic heights, explains the correction needed to account for the non-parallelism of equipotential surfaces, and discusses how these corrections were used in NAVD 88. The fourth paper presents a review of current best practices for heights measured with GPS. [ABSTRACT FROM AUTHOR]

In order to enhance data transmission security within internet network, this paper consider a signature reconfiguration scheme over wavelength-coded network coder/decoders (codecs). We propose the reconfiguration scheme of composite signatures in which optical network codecs reconfigure their signature keys in a tractable way to enhance system confidentiality for coded wavelength-division multiplexing (WDM) transmissions. Based on conventional maximal-length sequence (M-sequence) codes over arrayed-waveguide-grating (AWG) codecs, composite signatures of relative prime-length M-sequence codes are structured to identify network node users. Network codecs change their signatures dynamically such that eavesdroppers cannot keep up with the speed of code changing, and thus unable to detect the channel waveform to descramble the code. Evaluated results show the effectiveness of the proposed approach via composite signatures reconfiguration against practical eavesdropping. [ABSTRACT FROM AUTHOR]

Introduction Clinical extraoral examination prior to orthodontic treatment includes face analysis (front and profile). Development of computer technology has increased efficacy and simplified this process through automating several steps of the analysis. The aim of this paper was to examine the possibility of automatic determining of linear measurements based on the facial image of a patient. Material and Methods Based on the set of 20 patients in NHP (Natural Head Position) position, three sets of measurements were conducted. Trained orthodontist performed positioning of predefined points on the image of the patient two times with one week apart, after which the points were automatically determined using customized computer software. Based on the position of the points, measurements for bizygomatic distance, upper and lower facial height and full facial height were computed. Three sets of measurements were compared and statistically analyzed. Results showed that computer software produced measurements comparable to measurements obtained by a trained orthodontist. Statistical analysis included calculating mean values and standard deviations, as well as paired two-tailed T-test. Differences between measurements ranged from 0.03% to 0.6% suggesting that automatic method can be successfully used. Conclusions The results of this research suggest that it is possible to ease, accelerate and automate work of the orthodontist on the image analysis using suitable software without significant differences in measured values. [ABSTRACT FROM AUTHOR]

Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, we describe the way in which traditional Indonesian games can support the learning of linear measurement. Previous research has revealed that young children tend to perform measurement as an instrumental procedure. This tendency may be due to the way in which linear measurement has been taught as an isolated concept, which is separate from children's daily experiences. Consequently, a set of experience-based activities was designed to help grade 2 students to connect their learning of linear measurement to their daily experiences. Design research was chosen as a means of designing and analysing the hypothetical learning trajectory. Theoretical development is driven by a cyclical process of designing instructional activities, teaching experiments and retrospective analysis. The main design heuristic that was used is the principle of emergent modelling. The analysis of the teaching experiments showed that conflicts of fairness while playing the game could be used to help students to acquire the concept of a standard unit of measurement. [ABSTRACT FROM AUTHOR]

Copyright of Gazi University Journal of Gazi Educational Faculty (GUJGEF) is the property of Gazi University Journal of Gazi Educational Faculty (GUJGEF) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An on-the-go infield machine vision system was developed to measure internode length (i.e., the distance between main stem nodes) of cotton (Gossypium hirsutum L.) plants, which is a significant indicator of past water stress. An infield vehicle was developed to convey the machine vision system automatically across the crop canopy. This paper presents an evaluation of the devised system under a range of operational and field conditions. On average, the vision system's internode length detection rate ranged from 12 measurements per 100 plants for compact plants when the sun was directly overhead with respect to the camera, to 64 measurements per 100 plants for vigorous plants when the sunlight was perpendicular to the camera view angle. Imaging at night time using 850 nm near-infrared illumination resulted in internode length detection rates not significantly different from the most reliable daylight conditions. Both across-row and along-row operations of the system were evaluated, with the system yielding internode length measurements for groundspeeds up to 0.20 m/s for along-row operation. Visual occlusion of the main stem nodes by foliage and variations in natural lighting conditions were observed to be the principal reasons for internode lengths not being detected successfully for every plant. However, from the success rates observed, it is concluded that the system has the practical capability to map internode length across a field and hence, identify spatial trends in internode length from which trends in plant water stress can be inferred. [ABSTRACT FROM AUTHOR]

This paper analyses the relationship between the cutting forces and length, according to experimental results obtained in lights alloys, in particular UNS A97050-T7, UNS A92024-T3, during the dry drilling. The tests have been performed with several cutting speed, 83 m/min, 60 m/min and 50 m/min. Box-Cox transformations have allowed finding a fitted model and determining a significant relationship between maximum cutting forces, for each hole, and cutting length. Thus, it is possible to establish prediction limits for new observations of cutting forces, at 95% confidence level. [ABSTRACT FROM AUTHOR]

Copyright of Revista Internacional de Desastres Naturales, Accidentes e Infraestructura Civil is the property of University of Puerto Rico and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: In this paper we present new results on the approximate parallel construction of Huffman codes. Our algorithm achieves linear work and logarithmic time, provided that the initial set of elements is sorted. This is the first parallel algorithm for that problem with the optimal time and work. Combining our approach with the best known parallel sorting algorithms we can construct an almost optimal Huffman tree with optimal time and work. This also leads to the first parallel algorithm that constructs exact Huffman codes with maximum codeword length H in time with processors, if the elements are sorted. [Copyright &y& Elsevier]

An experimental investigation to determine the transfer length of a seven-wire prestressing strand in different concretes is presented in this paper. A testing technique based on the analysis of bond behaviour by means of measuring the force supported by the prestressing strand on a series of specimens with different embedment lengths has been used. An analytical bond model to calculate the transfer length from an inelastic bond stress distribution along the transfer length has been obtained. A relationship between the plastic bond stress for transfer length and the concrete compressive strength at the time of prestress transfer has been found. An equation to predict the average and both the lower bound and the upper bound values of transfer length is proposed. The experimental results have not only been compared with the theoretical prediction from proposed equations in the literature, but also with experimental results obtained by several researchers. [ABSTRACT FROM AUTHOR]

The article discusses the study which examines the influence of wire geometry on screen plate capacity and accept quality. Researchers have tested ten screen plate geometries that differs in slot and wire width, profile height, wire height and accept-side rounding with water and thermomechanical pulp. It shows that despite of the decrease in open area, the capacity of the screen plate has increased with increasing slot width, decreasing wire height or increasing profile height, and with increasing wire width. Results of the study can be used for designing wire geometries and choosing the optimal screen basket for a screening position.