Academic literature on the topic 'Grip pattern'
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Journal articles on the topic "Grip pattern"
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Wong, Ming-Horng, Boon-Chin Yeo, Poh-Kiat Ng, and Wei-Jun Choong. "Data Acquisition System and Pattern Image Generations for Hand Grip Device." International Journal on Robotics, Automation and Sciences 3 (November 8, 2021): 13–18. http://dx.doi.org/10.33093/ijoras.2021.3.3.
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Grip pattern is essential to understand how an object being held in hand. One of the solutions is to use the pressure sensing glove to capture the gripping pressure distributed on the surface of the palm. The objective of this project is to develop a data acquisition system for a gripping device that can capture the grip patterns when a person is gripping an object. The design comprises of Velostat sheet, rows, and columns of conductive threads, that are sandwiched and layered to form a glove with pressure sensor grids. Arduino is used to generate the signals for data acquisition and interface with the MATLAB program through serial communication. On the MATLAB, the sensor data are organized and represented in hand pattern color image. Voltage Divider Rule (VDR) was used in an experiment with different resistor values and the effect of the image patterns were observed. Another experiment has been designed to find out the grip consistency. The results show that resistor values 330ohm can cause the image pattern create noises. Meanwhile, 4.7kohm resistance value is sufficient to eliminate most of the noises made in the pattern images. In this paper, different grip images can be obtained from different grip activities, such as holding toothbrush, lifting dumbbell, and pressing syringe. Future works can be done in resolution improvement and grip pattern recognition.
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Ojigho, Efe Jennifer, and Igho Emmanuel Odokuma. "Pencil Grip Patterns of Students and Skilled Workers." Journal of College of Medical Sciences-Nepal 15, no. 1 (March 14, 2019): 53–58. http://dx.doi.org/10.3126/jcmsn.v15i1.19286.
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Background: Pencil grip can be defined via detailed descriptions of the variables constituting the grip and it commences in the preschool years with writing instruments and therefore relevant to graphologists, forensic medicine and anthropology. The purpose of this investigation was to describe the diversity of pencil grip patterns among students and skilled workers in Delta State, Nigeria. The research also aimed at determining the effects of sociodemographic factors, handedness,and handwriting speed on pencil grip patters.
Methods: Stratified random sampling was employed in this cross sectional observational study. Five hundred and fourty three volunteers between the ages of 11-77 years were investigated. Students were observed while writing from their textbooks and skilled workers were observed writing from any available news paper. Photograph of the writing hand was captured with the digital canon camera. The data was analysed using the Statistical Package for Social Sciences (SPSS) 20. Kruska wallis test was used to establish relationship between pencil grip patterns and sociodemographic factors. Handwriting speed was determined by a speed score (letters per minute) and timed for 60 secounds for each participant. A self administered questionnaire was used to obtain data on sociodemographic factors.
Results: This investigation demonstrates that gender had a significant effect on pencil grip patterns among secondary students (p<0.05)(K.W=7.54. df=1. p=0.01). Further observation showed that age and profession had a significant effect on pencil grip patterns among skilled workers at p<0.05 (K.W= 43.09,134.69 ,df=3,3, p=0.00,0.00).
Conclusions: Findings from this investigation present the dynamic tripod grip as the most predominant grip pattern in the studied population.
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Marzke, Mary W. "Tool making, hand morphology and fossil hominins." Philosophical Transactions of the Royal Society B: Biological Sciences 368, no. 1630 (November 19, 2013): 20120414. http://dx.doi.org/10.1098/rstb.2012.0414.
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Was stone tool making a factor in the evolution of human hand morphology? Is it possible to find evidence in fossil hominin hands for this capability? These questions are being addressed with increasingly sophisticated studies that are testing two hypotheses; (i) that humans have unique patterns of grip and hand movement capabilities compatible with effective stone tool making and use of the tools and, if this is the case, (ii) that there exist unique patterns of morphology in human hands that are consistent with these capabilities. Comparative analyses of human stone tool behaviours and chimpanzee feeding behaviours have revealed a distinctive set of forceful pinch grips by humans that are effective in the control of stones by one hand during manufacture and use of the tools. Comparative dissections, kinematic analyses and biomechanical studies indicate that humans do have a unique pattern of muscle architecture and joint surface form and functions consistent with the derived capabilities. A major remaining challenge is to identify skeletal features that reflect the full morphological pattern, and therefore may serve as clues to fossil hominin manipulative capabilities. Hominin fossils are evaluated for evidence of patterns of derived human grip and stress-accommodation features.
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Shang, Xiaoxin. "Grip-pattern verification for a smart gun." Journal of Electronic Imaging 17, no. 1 (January 1, 2008): 011017. http://dx.doi.org/10.1117/1.2892675.
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Seo, Ae-Rim, Mi-Ji Kim, and Ki-Soo Park. "Regional Differences in the Association between Dietary Patterns and Muscle Strength in Korean Older Adults: Data from the Korea National Health and Nutrition Examination Survey 2014–2016." Nutrients 12, no. 5 (May 12, 2020): 1377. http://dx.doi.org/10.3390/nu12051377.
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Objectives: Adequate nutrition is an important factor to prevent sarcopenia in older adults. The purpose of this study was to identify the regional differences in the association between dietary pattern and muscle strength in older Korean adults. Methods: This study was based on data from the Korea National Health and Nutrition Examination Survey (KNHANES) in 2014–2016. Muscle strength was measured by grip strength, and dietary patterns were derived by a cluster analysis using the k-means algorithm. Multiple logistic regression analyses were applied to determine the associations between factors (dietary patterns and residential areas) and grip strength. Results: Most participants in the rural area group (50.4%) had the Cluster Three dietary pattern (diet dominant in white rice and kimchi), while most people in the urban area group (43.8%) and the metropolitan area group (53.2%) had the Cluster One dietary pattern (diet dominant in fruits and fish). Those having poor hand grip strength represented 25.8% of the total in rural, 20.6% in urban, and 17.9% in metropolitan (p = 0.009) areas. Upon adjustment for socio-demographic characteristics, health behaviors, and co-morbidity, the odds ratio of Cluster Two (diet dominant in meat) was 1.601 (95%, CI: 1.001–2.563, p = 0.050) compared to the Cluster Three dietary pattern, but there was no significant difference in residence. Conclusions: Muscle strength in the elderly was more related to dietary pattern than was residence. Education and support for conveying the importance of protein intake in the elderly are required to motivate adequate nutrition. In addition, these actions should lead to prevention of muscle weakness and further prevent frailty.
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Wankhede, Harish A., and Dipti A. Nimje. "Pencil Grip Pattern and Its Effect on Handwriting in Medical Students of Maharashtra." Indian Journal of Anatomy 6, no. 3 (2017): 293–96. http://dx.doi.org/10.21088/ija.2320.0022.6317.7.
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GÜLKE, J., N. J. WACHTER, P. KATZMAIER, T. EBINGER, and M. MENTZEL. "Detecting Submaximal Effort in Power Grip by Observation of the Strength Distribution Pattern." Journal of Hand Surgery (European Volume) 32, no. 6 (December 2007): 677–83. http://dx.doi.org/10.1016/j.jhse.2007.05.020.
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This study examined patterns of grip strength when maximal and submaximal effort are applied. Using a sensor glove, 50 healthy subjects performed two different power grips. Both maximal and submaximal gripping showed characteristic patterns of strength distribution that were independent of the degree of power applied. Significant differences were also noted in the strength distribution patterns, depending on whether the grip was performed at maximal, or submaximal, strength. The small finger plays a decisive role in this. In maximal strength gripping, the total measured strength is distributed relatively evenly over all four fingers, with each finger contributing between 23% and 27% of the total strength. In submaximal strength gripping, the little finger is involved very little and only contributes between 14% and 15% of the total strength, with the remainder of the gripping distributed relatively evenly between the index, middle and ring fingers, each of which contributes between 26% and 32% of the total.
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Lee, Yushin, Joong Hee Lee, Yong Min Kim, Jihwan Lee, Sanghyun Kwon, Hyungmin Sim, and Myung Hwan Yun. "The Effects of Curvature of Edge Screen on Subjective Feelings in Smartphone Usage." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 61, no. 1 (September 2017): 1269–70. http://dx.doi.org/10.1177/1541931213601798.
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As the penetration rate of Smartphone grows high and the market gets saturated, the technological and aesthetic progress for manufacturers are heavily demanded to sustain their market share. To meet such demands, manufacturers continuously improve the design of their products. As the design of smartphone varies by manufacturers, there have been many existing researches to identify the relationships between various physical dimensions of smartphones and how users feel (Chowdhury, A., & Kanetkar, M., 2017; Lee, S., Kyung, G., Lee, J., Moon, S. K., & Park, K. J., 2016; Pereira, A., Miller, T., Huang, Y. M., Odell, D., & Rempel, D., 2013; Sung, K., Cho, J., & Freivalds, A., 2016). Recently, in accordance with the development and improvement of flexible displays, curved displays have been applied on smartphones with various curvatures. The popular one among them is the “edge screen” on smartphones, which refers to curved display implemented either on one single side or both sides. Considering that physical dimensions such as shape and size are the important features for customer satisfaction (Hwang, 2012; Ling, C., Hwang, W., and Salvendy, G., 2007), curvature of edge screen can influence on user comfort when the users carry out their tasks on their smartphones. However, such issue hasn’t been dealt in previous studies. Therefore, as a preliminary study, this study aimed to identify the relationships between curvatures of edge screens and subjective feelings in smartphone usage with various usage patterns using subjective evaluation experiment. In this laboratory study, 47 subjects assessed their subjective feelings (grip comfort, control comfort, stability, front visibility, side visibility) towards given samples with four different kinds of usage patterns. The samples were designed with a 5.5-inch flat display of 16:9 ratio (Samsung Galaxy Note 2) as a main screen along with a curved display of different radii of curvatures (R, unit: mm) on the right edge as an edge screen: 4R, 6R, 8R, and 10R. The usage patterns were defined according to which hands were used for grip and control: Grip with right hand and control with right thumb (usage pattern (a)), Grip with left hand and control with right index finger (usage pattern (b)), Grip with both hands and control with both thumbs (usage pattern (c)), and Grip with right hand without control (usage pattern (d)). The statistically significant results of one-way analysis of variance (ANOVA) and post hoc analysis (Duncan’s test) showed that the sample with 4R curvature belonged to the third homogeneous subset (in descending order) for the front visibility while it belonged to the second homogeneous subset for the control comfort in usage pattern (b) and (c). Whereas the sample with 6R curvature belonged to the second homogeneous subset for the front visibility and the second homogeneous subset for the control comfort in usage pattern (b) and (c). In case of the sample with 8R curvature, it was within the first homogeneous subset throughout all analyses conducted. Lastly, the sample with 10R curvature was within the second homogeneous subset for the grip comfort in usage pattern (d). Therefore, it is concluded that the optimal radius of curvature for edge screens is 8R. Although there were some samples evaluated better than the 8R sample in descriptive manner, however, such results were not statistically significant. This study is expected to contribute towards the design of smartphones with edge screens in terms of better subjective feeling by various usage patterns. However, this study is yet a preliminary study which is based on a subjective evaluation. In the future research, more criteria of subjective feeling are needed to be evaluated to decide more precise optimal curvature. In addition, objective evaluation method such as analysis of muscle activity, motion tracking analysis, or behavior analysis could be applied to verify the reliability and validity of the result of this study.
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Liang, Chen, Haowen Li, Hoda Mousavi, Guolin Wang, and Kangying Yu. "Evaluation and improvement of tire rolling resistance and grip performance based on test and simulation." Advances in Mechanical Engineering 12, no. 12 (December 2020): 168781402098117. http://dx.doi.org/10.1177/1687814020981173.
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In order to clarify the contradictory mechanism between tire rolling resistance and grip performance, ten (10) 205/55 R16 radial tires with different tread patterns were selected as the research objects. Using VIC-3D non-contact strain measurement system, the pattern deformation in the contact area under vertical load was tested and the relevant deformation parameters of the contact area were extracted. Correlation analysis was used to establish the relationship between the identified deformation parameters and tire performance indicators. Then the contradiction mechanism between tire rolling resistance and grip performance was identified. The mechanism is such that, in order to improve the grip performance of the tire, it is necessary to reduce the transverse tensile strain of the tread in the contact area and increase the longitudinal tensile strain of the tread, but with the increase of the longitudinal tensile strain, the rolling resistance of the tire will also increase, which leads to the contradiction between tire rolling resistance and grip performance. In order to better understand and solve this contradiction, a finite element model of 205/55R16 tire with complex pattern was established. The influence of the number and width of transverse grooves in outer shoulder area on tire rolling resistance and grip performance was analyzed by numerical simulation, where it was identified that, the longitudinal tensile deformation of the tread is the main cause of contradiction between the two performances. An optimized design of concave transverse groove with narrow groove in the middle and wide groove at both ends was proposed in the outer shoulder area to resolve the contradiction. Compared with the original scheme, the rolling resistance of the optimized scheme was reduced by 2.112 N, and the grip force saw an increase of 10.196 N, and thus delivering a cooperative improvement of tire rolling resistance and grip performance.
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Yun, Myung Hwan, and Andris Freivalds. "Analysis of Hand Tool Grips." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 39, no. 10 (October 1995): 553–57. http://dx.doi.org/10.1177/154193129503901003.
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An efficient measurement and evaluation system for hand tool tasks can provide a practical solution to the problem of designing and evaluating manual tool tasks in the workplace. Such a prototype system, termed the data glove, was developed by overlaying twelve Force Sensitive Resistors on an posture-measuring glove (Cyberglove™, Virtual Technologies, 1992) with eighteen joint angle sensors. To validate the data glove, hand posture and grip force was measured on sixteen different cylindrical grip tasks for six subjects. A factor analysis of the grip force distributions on the hand indicated that three major areas of force concentration occurred: 1) an area of high force levels termed the ‘active’ area, 2) an area of intermediate force levels termed the ‘support’ area, and 3) an area of low force levels termed the ‘inactive’ area. The different grips were also classified and ranked for levels of radian/ulnar deviation torques and flexion/extension torques, and then combined with the force information to yield a pattern of grip degradation with increasing levels of grip stress. A validation experiment comparing the data glove force output with the muscle surface EMG measurement yielded a significant, high correlation between the two measures.
Dissertations / Theses on the topic "Grip pattern"
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Mohan, Deepak. "Real-time detection of grip length deviation for fastening operations: a Mahalanobis-Taguchi system (MTS) based approach." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.mst.edu/thesis/pdf/DeepakMohanThesisFinal_09007dcc80410b1d.pdf.
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Thesis (M.S.)--University of Missouri--Rolla, 2007.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed October 24, 2007) Includes bibliographical references.
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Gomes, Maria Cecília. "Pattern Operators for Grid Environments." Doctoral thesis, FCT - UNL, 2007. http://hdl.handle.net/10362/1522.
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The definition and programming of distributed applications has become a major research
issue due to the increasing availability of (large scale) distributed platforms
and the requirements posed by the economical globalization. However, such a task
requires a huge effort due to the complexity of the distributed environments: large
amount of users may communicate and share information across different authority
domains; moreover, the “execution environment” or “computations” are dynamic
since the number of users and the computational infrastructure change in time. Grid
environments, in particular, promise to be an answer to deal with such complexity, by
providing high performance execution support to large amount of users, and resource
sharing across different organizations. Nevertheless, programming in Grid environments
is still a difficult task. There is a lack of high level programming paradigms
and support tools that may guide the application developer and allow reusability of
state-of-the-art solutions.
Specifically, the main goal of the work presented in this thesis is to contribute to
the simplification of the development cycle of applications for Grid environments by
bringing structure and flexibility to three stages of that cycle through a commonmodel.
The stages are: the design phase, the execution phase, and the reconfiguration phase.
The common model is based on the manipulation of patterns through pattern operators,
and the division of both patterns and operators into two categories, namely
structural and behavioural. Moreover, both structural and behavioural patterns are
first class entities at each of the aforesaid stages. At the design phase, patterns can
be manipulated like other first class entities such as components. This allows a more
structured way to build applications by reusing and composing state-of-the-art patterns.
At the execution phase, patterns are units of execution control: it is possible, for
example, to start or stop and to resume the execution of a pattern as a single entity. At
the reconfiguration phase, patterns can also be manipulated as single entities with the
additional advantage that it is possible to perform a structural reconfiguration while
keeping some of the behavioural constraints, and vice-versa. For example, it is possible
to replace a behavioural pattern, which was applied to some structural pattern,
with another behavioural pattern.
In this thesis, besides the proposal of the methodology for distributed application
development, as sketched above, a definition of a relevant set of pattern operators
was made. The methodology and the expressivity of the pattern operators were assessed
through the development of several representative distributed applications. To
support this validation, a prototype was designed and implemented, encompassing
some relevant patterns and a significant part of the patterns operators defined. This
prototype was based in the Triana environment; Triana supports the development and
deployment of distributed applications in the Grid through a dataflow-based programming
model. Additionally, this thesis also presents the analysis of a mapping of some
operators for execution control onto the Distributed Resource Management Application
API (DRMAA).
This assessment confirmed the suitability of the proposed model, as well as the
generality and flexibility of the defined pattern operatorsDepartamento de Informática and Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa; Centro de Informática e Tecnologias da Informação of the FCT/UNL; Reitoria da Universidade Nova de Lisboa; Distributed Collaborative Computing Group, Cardiff University, United Kingdom; Fundação para a Ciência e Tecnologia; Instituto de Cooperação Científica e Tecnológica Internacional; French Embassy in Portugal; European Union Commission through the Agentcities.NET and Coordina projects; and the European Science Foundation, EURESCO.
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Vialaneix, Guillaume. "Algorithmes parallèles de manipulation de maillages." Thesis, Paris, ENST, 2012. http://www.theses.fr/2012ENST0068/document.
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Nous traitons dans cette thèse des différents aspects de la manipulation de maillages, et de la façon dont ces opérations peuvent être effectuées en parallèle, ou en mémoire distribuée, à l’heure où les GPUs comme les super-calculateurs deviennent de plus en plus utilisés. Ainsi, nous présentons des algorithmes de lissage surfacique et volumique, inspirés d’algorithmes de traitement d’images (filtre bilatéral, histogrammes locaux). Après ces manipulations de géométrie, nous abordons des problématiques topologiques comme le remaillage local, dans le but de générer, à partir d’un maillage tétraédrique, une couche limite de cellules prismatiques et hexaédriques de bonne qualité, permettant des simulations de mécanique des fluides dans ces ones proches de la surface. Enfin, nous décrivons une technique de maillage basée sur des interactions particulaires, permettant de générer des maillages à dominante quadrangulaireThis thesis deals with different aspects of mesh processing, and the way those operations can be done in parallel, or using distributed memory, when GPUs and supercomputers are more and more commonly used. We present surfacic and volumetric mesh smoothing algorithms, based upon image processing techniques (bilateral filter, local histograms). After those geometric considerations, we talk about topologic methods, as local remeshing, enabling one to generate, from a tetrahedral mesh, one layer of good quality prisms and hexahedron, allowing fluid mechanics simulations in those near-surface areas. Finally, we present a meshing technique based upon particular interactions, in order to construct quad-dominant meshes
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Khouri, Noor K. "Structural grid shell design with Islamic pattern topologies." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111282.
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Thesis: S.M. in Building Technology, Massachusetts Institute of Technology, Department of Architecture, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 81-84).
Geometric patterns, pioneered centuries ago as a dominant form of ornamentation in Islamic architecture, represent an abundant source of possible topologies and geometries that can be explored in the preliminary design of discrete structures. This diverse design space motivates the coupling between Islamic patterns and the form finding of funicular grid shells for which structural performance is highly affected by topology and geometry. This thesis examines one such pattern through a parametric, performance-driven framework in the context of conceptual design, when many alternatives are being considered. Form finding is conducted via the force density method, which is augmented with the addition of a force density optimization loop to enable grid shell height selection. A further modification allows for force densities to be scaled according to the initial member lengths, introducing sensitivity to pattern geometry in the final form-found structures. The results attest to the viable synergy between architectural and structural objectives through grid shells that perform as well as, or better than, quadrilateral grid shells. Historic and cultural patterns therefore present design opportunities that both expand the conventional grid shell design vocabulary and offer designers an alternative means of referencing vernacular traditions in the modern built environment, through a structural engineering lens. Key words: grid shell, structural topology, Islamic pattern, parametric design, performance driven design, force density method, form finding.
by Noor K. Khouri.
S.M. in Building Technology
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Spiridonov, Alexey. "Pattern-avoidance in binary fillings of grid shapes." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/50597.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2009.Includes bibliographical references (p. 87-88).
A grid shape is a set of boxes chosen from a square grid; any Young diagram is an example. We consider a notion of pattern-avoidance for 0-1 fillings of grid shapes, which generalizes permutation pattern-avoidance. A filling avoids a set of patterns if none of its sub-shapes, obtained by removing some rows and columns, equal any of the patterns. We focus on patterns that are pairs of 2 x 2 fillings. Totally nonnegative Grassmann cells are in bijection with Young shape fillings that avoid particular 2 x 2 pair, which are, in turn, equinumerous with fillings avoiding another 2 x 2 pair. The latter ones correspond to acyclic orientations of the shape's bipartite graph. Motivated by this result, due to Postnikov and Williams, we prove a number of such analogs of Wilf-equivalence for these objects - that is, we show that, in certain classes of shapes, some pattern-avoiding fillings are equinumerous with others. The equivalences in this paper follow from two very different bijections, and from a family of recurrences generalizing results of Postnikov and Williams. We used a computer to test each of the described equivalences on a diverse set of shapes. All our results are nearly tight, in the sense that we found no natural families of shapes, in which the equivalences hold, but the results' hypotheses do not. One of these bijections gives rise to some new combinatorics on tilings of skew Young shapes with rectangles, which we name Popeye diagrams. In a special case, they are exactly Hugh Thomas's snug partitions for d = 2. We show that Popeye diagrams are a lattice, and, moreover, each diagram is a sublattice of the Tamari lattice. We also give a simple enumerative result.
by Alexey Spiridonov.
Ph.D.
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Cuthill, Fergus. "The influence of snow microstructure and properties on the grip of winter tyres." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29534.
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The friction of tyres on roads has been of practical importance for many years with nearly 80% of terrestrial traffic making use of rubber tyres. Tyres provide the grip required for vehicle acceleration, braking and cornering. In order for a tyre to grip on a snow covered surface friction mechanisms such as “ploughing”, (where sharp tread block edges dig into and break bonds between the snow grains) and fluid film lubrication must be considered. These are not present when a tyre interacts with tarmac. In addition metamorphism of the snow over time can result in variations of the structure and mechanical properties, this can occur rapidly especially when dealing with temperatures close to snows melting point. When full car-scale outdoor testing is carried out the snow conditions cannot be controlled and vary daily. This means the snow properties must be measured every day so that any observed variations in friction can be attributed to the tyres rather than the snow. At present the simple measurements being carried out on the snow tracks have not proved sufficient to pick up on the variations in the snow. This leads to inconsistent results: one tyre behaves differently on two different days, even though the snow was measured to be the same. This has resulted in the need for further study of the way snow variations influence the grip of winter tyres. The primary aim of this study is to identify which snow properties contribute to the friction of tyres on snow and be able to estimate the friction from measurements of snow properties. This work is the first comprehensive study to combine: multiple snow properties, microstructure characterisation, measurement of friction behaviour and different snow (both artificial and natural). In order to study the way snow affects the grip of winter tyres, methods of manufacturing artificial snow with consistent mechanical properties and microstructure are used. A method of blending ice chips (a solid state fracturing process) and compressing the resulting snow to form a test track was developed during a previous PhD carried out in our group. An alternate snow microstructure was created by using an established process of creating snow by vapour deposition. The process was simplified and downscaled, the resulting snow consisted of large dendritic grains, very different to the blended ice chips. Both snows were pressed in identical manners to create snow testing tracks. In addition, natural snow collected from the field was tested to compare with the artificial snow. In order to investigate how the variations in the snow affected the friction of tyres extensive testing was carried out in a cold room using a linear tribometer, using procedures established in previous studies. Two analytical rubber samples were used to investigate the friction, a rounded edge sample and a siped sample. Testing was carried out at -10°C at speeds of 0.01m/s, 0.1m/s and 1m/s. A significant part of this PhD involved the development of new methods and equipment which have not been used to study snow in this way before. In order to characterise mechanical properties, shear testing, compression testing and cohesion testing were carried out. To investigate snow microstructure, surface profilometry, microscopy and X-ray microtomography were used. Correlating the changes observed in snow characteristics with the changes recorded in the coefficient of friction has allowed the development of an empirical equation. This can be used to predict the coefficient of friction of a given snow based on three relatively simple snow measurements: a compression test to calculate the effective modulus, a roughness measurement to calculate the peak count density and a snow penetration test. For the first time this study allows us to use the empirical equation to estimate the relative contributions of the ploughing and surface friction mechanisms to the total friction. This allows the comparison of full car-scale test data as it is now possible to account for variations in the snow test tracks.
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Moraal, Reinart Johan. "Pattern synthesis and design of a microstrip wire grid monopulse antenna." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/62783.
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The design of a monopulse microstrip wire grid antenna array is presented with simultaneously low side lobe levels in the sum pattern as well as both azimuth difference and elevation difference patterns. Monopulse antennas are a class of antennas used for direction finding in radar systems, and the control of side lobe levels is important to help with clutter rejection. The microstrip wire grid array is ideally suited to monopulse applications, and it has been shown in the literature that side lobes can be lowered by implementing an excitation taper across the aperture. Although it has been demonstrated in the literature that side lobes could be lowered for the sum pattern by applying a Taylor taper to the element excitation, it has not been shown that the antenna can be designed to produce an exact side lobe level. This work develops a synthesis method to design an excitation taper that would produce simultaneously low side lobes for the sum and both difference patterns. The resulting side lobe levels are a compromise between the patterns, since it is not possible to have arbitrarily low side lobe levels in all the antenna patterns without using complex feed structures and incorporating sub-arraying. This is true for monopulse antennas in general. The result of this work shows that it is quite difficult to achieve an exact side lobe requirement with a specific excitation taper, since mutual coupling and the current distribution at the feed affect the current distribution across the entire antenna in different ways depending on the antenna mode, or pattern generated.Dissertation (MEng)--University of Pretoria, 2017.
Electrical, Electronic and Computer Engineering
MEng
Unrestricted
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Yaka, Cane. "Studies of axonal regeneration on a grid pattern of extracellular matrix proteins." Thesis, Uppsala universitet, Institutionen för neurovetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-205230.
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Nigri, Simone. "Ottimizzatore per configurazione automatica di algoritmi di pattern matching." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Find full textAbstract:
Il tema del riconoscimento di oggetti, siano essi microscopici componenti in grandi catene di assemblaggio o segnali grafici posti su pacchi in spedizione, è uno degli argomenti più rilevanti all'interno del vasto mondo racchiuso nel settore interdisciplinare rappresentato da Computer Vision, inerente all'analisi di immagini al fine di estrapolarne informazioni.
Nonostante ciò, l'utilizzo e la configurazione di strumenti (o tool) il cui obiettivo è esattamente quello di rilevare particolari modelli noti a priori in diverse immagini, potrebbe essere un compito particolarmente arduo per un utente medio senza preventiva conoscenza in tale ambito.
Al fine di aiutare e guidare tale settore di utenza, lo scopo dell'elaborato sviluppato è, quindi, quello di creare un sistema di ottimizzazione automatica del processo di configurazione di strumenti dediti al Pattern Matching, considerando come study-case il setup del componente software Pattern Sort gentilmente messo a disposizione da Datalogic S.p.A.
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Shin, Sangmook. "Reynolds-Averaged Navier-Stokes Computation of Tip Clearance Flow in a Compressor Cascade Using an Unstructured Grid." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/28947.
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A three-dimensional unstructured incompressible RANS code has been developed using artificial compressibility and Spalart-Allmaras eddy viscosity model. A node-based finite volume method is used in which all flow variables are defined at the vertices of tetrahedrons in an unstructured grid. The inviscid fluxes are computed by using the Roe's flux difference splitting method, and higher order accuracy is attained by data reconstruction based on Taylor series expansion. Gauss theorem is used to formulate necessary gradients. For time integration, an implicit scheme based on linearized Euler backward method is used.
A tetrahedral unstructured grid generation code has been also developed and applied to the tip clearance flow in a highly staggered cascade. Surface grids are first generated in the flow passage and blade tip by using several triangulation methods including Delaunay triangulation, advancing front method and advancing layer method. Then the whole computational domain including tip gap region is filled with prisms using the surface grids. Each prism is divided into three tetrahedrons. To accomplish this division in a consistent manner, connectivity pattern is assigned to each triangle in the surface grids. A new algorithm is devised to assign the connectivity pattern without reference to the particular method of triangulation. This technique offers great flexibility in surface grid generation.
The code has been validated by comparisons with available computational and experimental results for several test cases: invisicd flow around NACA section, laminar and turbulent flow over a flat plate, turbulent flow through double-circular arc cascade and laminar flow through a square duct with 90° bend. For the laminar flat plate case, the velocity profile and skin friction coefficient are in excellent agreement with Blasius solution. For the turbulent flat plate case, velocity profiles are in full agreement with the law of the wall up to Reynolds number of 1.0E8, however, the skin friction coefficient is under-predicted by about 10% in comparison with empirical formula. Blade loading for the two-dimensional circular arc cascade is also compared with experiments. The results obtained with the experimental inflow angle (51.5° ) show some discrepancies at the trailing edge and severely under-predict the suction peak at the leading edge. These discrepancies are completely remedied if the inflow angle is increased to 53.5° . The code is also capable of predicting the secondary flow in the square duct with 90° bend, and the velocity profiles are in good agreement with measurements and published Navier-Stokes computations.
Finally the code is applied to a linear cascade that has GE rotor B section with tip clearance and a high stagger angle of 56.9° . The overall structure of the tip clearance flow is well predicted. Loss of loading due to tip leakage flow and reloading due to tip leakage vortex are presented. On the end wall, separation line of the tip leakage vortex and reattachment line of passage vortex are identified. The location of the tip leakage vortex in the passage agrees very well with oil flow visualization. Separation bubble on the blade tip is also predicted. Mean streamwise velocity contours and cross sectional velocity vectors are compared with experimental results in the near wake, and good agreements are observed. It is concluded that Spalart-Allmaras turbulence model is adequate for this type of flow field except at locations where the tip leakage vortex of one blade interacts with the wake of a following blade. This situation may prevail for blades with longer span and/or in the far wake. Prediction of such an interaction presents a challenge to RANS computations.
The effects of blade span on the flow structure have been also investigated. Two cascades with blades of aspect ratios of 0.5 and 1.0 are considered. By comparing pressure distributions on the blade, it is shown that the aspect ratio has strong effects on loading distribution on the blade although the tip gap height is very small (0.016 chord). Grid convergence study has been carried out with three different grids for pressure distributions and limiting streamlines on the end wall.Ph. D.
Books on the topic "Grip pattern"
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Fisher, Karen G. Easy grid quilts. Paducah: American Quilter's Society, 2012.
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The grid book. Cambridge, MA: MIT Press, 2009.
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Levy, Stu. Grid-portraits. Portland, Or: Nazraeli Press, 2010.
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Torres-García, Joaquín. Torres-Garcia, grid, pattern, sign: Paris-Montevideo, 1924-1944. [London]: Arts Council of Great Britain, 1985.
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1928-2007, LeWitt Sol, and Williams College. Museum of Art, eds. Sol LeWitt: The well-tempered grid. Williamstown, Massachusetts: Williams College Museum of Art, 2012.
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Martins, Tiago, and Rui Neves. Stock Exchange Trading Using Grid Pattern Optimized by A Genetic Algorithm with Speciation. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-76680-1.
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Kanellis, A. G. Thermographic investigation of the stress patterns at joints in GRP components. Manchester: UMIST, 1993.
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Magloire, Alain. Grep: Searching for a Pattern. Iuniverse Inc, 2000.
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Journals, LaRays Smart. Dot Grid: Blue Pattern Design. Independently Published, 2017.
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Journals, Ladybug. Dot Grid Journal: Abstract Butterfly Pattern Notebook Dotted Grid. Independently Published, 2017.
Find full textBook chapters on the topic "Grip pattern"
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Hamid, Malek, Hanan Mokhtar, Haikal S. Mislah, and Dian D. I. Daruis. "Effect of the Sequencing Pattern Through Counterbalancing, Randomization and One-Pattern on Maximal Hand Grip Strength Performance." In Advances in Intelligent Systems and Computing, 159–69. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63335-6_17.
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Jeannerod, M. "The Formation of the Finger Grip during Prehension a Cortically-Mediated Visuo-Motor Pattern." In Themes in Motor Development, 183–205. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4462-6_10.
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Shang, Xiaoxin, and Raymond N. J. Veldhuis. "Grip-Pattern Recognition in Smart Gun Based on Likelihood-Ratio Classifier and Support Vector Machine." In Lecture Notes in Computer Science, 289–95. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-69905-7_33.
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Matarazzo, Ury, Dekel Tsur, and Michal Ziv-Ukelson. "Efficient All Path Score Computations on Grid Graphs." In Combinatorial Pattern Matching, 211–22. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-38905-4_21.
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Zhang, Zhixiang, and Qinghua Li. "Automated Detection of Design Patterns." In Grid and Cooperative Computing, 694–97. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-24680-0_110.
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Yokoo, Hidetoshi. "Extension and Faster Implementation of the GRP Transform for Lossless Compression." In Combinatorial Pattern Matching, 338–47. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-13509-5_30.
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Guillén, Carlos, Guillermo De Ita, and Aurelio López-López. "A Novel Method for Counting Models on Grid Boolean Formulas." In Advances in Pattern Recognition, 322–31. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-15992-3_34.
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Magillo, Paola, and Lidija Čomić. "Transparent Management of Adjacencies in the Cubic Grid." In Pattern Recognition and Image Analysis, 283–94. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-04881-4_23.
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Xu, Xianghua, Jiajun Bu, Chun Chen, and Yong Li. "CIMES: A Collaborative Image Editing System for Pattern Design." In Grid and Cooperative Computing, 242–46. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-24679-4_51.
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Li, I.-Hui, Jyun-Yao Huang, I.-En Liao, and Jin-Han Lin. "A Sequence Classification Model Based on Pattern Coverage Rate." In Grid and Pervasive Computing, 737–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-38027-3_81.
Full textConference papers on the topic "Grip pattern"
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Veldhuis, Raymond N., Asker M. Bazen, Joost A. Kauffman, and Pieter Hartel. "Biometric verification based on grip-pattern recognition." In Electronic Imaging 2004, edited by Edward J. Delp III and Ping W. Wong. SPIE, 2004. http://dx.doi.org/10.1117/12.530967.
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Khatik, Raj, and Vijaypal Yadav. "Myoelectric Signal Based Multiple Grip Pattern Prosthetic Arm." In 2018 6th Edition of International Conference on Wireless Networks & Embedded Systems (WECON). IEEE, 2018. http://dx.doi.org/10.1109/wecon.2018.8782069.
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Shang, Xiaoxin, and Raymond N. J. Veldhuis. "Local Absolute Binary Patterns as Image Preprocessing for Grip-Pattern Recognition in Smart Gun." In 2007 First IEEE International Conference on Biometrics: Theory, Applications, and Systems. IEEE, 2007. http://dx.doi.org/10.1109/btas.2007.4401939.
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Shang, Xiaoxin, and Raymond N. J. Veldhuis. "Grip-Pattern Verification for Smart Gun Based on Maximum-Pairwise Comparison and Mean-Template Comparison." In 2008 IEEE Second International Conference on Biometrics: Theory, Applications and Systems. IEEE, 2008. http://dx.doi.org/10.1109/btas.2008.4699338.
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Gimunová, Marta, Tomáš Vodička, Kristián Jánsky, Miriam Kalichová, Antonín Zderčík, Alena Skotáková, Petr Hedbávný, and Kateřina Kolářová. "The effect of classical ballet, Slovakian folklore dance and sport dance on static postural control in female and male dancers." In 12th International Conference on Kinanthropology. Brno: Masaryk University Press, 2020. http://dx.doi.org/10.5817/cz.muni.p210-9631-2020-4.
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Purpose: Classical ballet, Slovakian folklore dance, and sport dance training differ in their way how to master the art of dance; however, postural control is essential for the correct exe-cution of complex movements used in all types of dance. The aim of this study was to analyse the differences in static postural control between classical ballet dancers, Slovakian folklore dancers and sport dancers and to analyse the effect of body mass, body height and toe grip strength on postural control. Methods: 68 dancers, between 17 to 28 years of age, participated in this study: 21 dancers from Slovakian folklore dance group VSLPT Poľana Brno (12 females, 9 males), 22 dancers from Brno Dance conservatory (16 females, 6 males) and 25 sport dancers competing at Brno Dance Open 2019 (12 females, 13 males). All participants were asked to stand upright, barefooted, arms along the body, both feet on the Emed-at platform (Novel GmbH, Germany) for 10 seconds with their eyes open to obtain the length of COP line (cm), average velocity of COP (cm/s), the elliptic area (mm2) and numerical eccentricity of the ellipse. The toe grip strength was measured for each foot when sitting using toe grip dynamometer (Takei Scien-tific Instruments, Niigata, Japan). To analyse the effect of dance style, to grip strength, body mass, body height, and gender on postural control variables, Kruskal Wallis test, and Spear-man Rank Order Correlation were used. Results: Abetter postural stability measured by the length and average velocity of COP was observed in sport dancers, compared to classical ballet and Slovakian folklore dancers. Sport dancers are used to a greater load on the forefoot and to a special foot roll-of pattern when dancing, which may lead together with a constantly changing environment during competi-tions to their enhanced postural stability. Despite the differences in dance training and dance footwear of female and male dancers (high-heel shoes in sport and Slovakian folklore female dancers, pointe shoes in female ballet dancers), no statistically significant difference in pos-tural variables between genders was observed. Similarly, in analysed dancers, no effect of age, body mass, and body weight on postural control were observed. The toe grip strength was not observed to affect the postural variables in this study. The greatest toe grip strength was observed in female ballet dancers, despite their younger age. Ballet dance training in-cludes repetitive exercises focused on foot and toes such as battement tendu or demi-pointe and en pointe positions probably resulting in the greater strength of the toes. Conclusion: In this study, better postural stability measured by the length and average ve-locity of COP was observed in sport dancers, compared to classical ballet and Slovakian folklore dancers. In analysed dancers, no effect of body mass, body weight, gender, and toe grip strength on postural control variables was observed. Future studies focused on postural stability changes in non-dancers after a sport dance, classical ballet and Slovakian folklore dance training program would provide additional knowledge about the process how each type of dance enhance the balance and other coordinative skills.
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Shen, Ninggang, Chelsey N. Pence, Robert Bowers, Yin Yu, Hongtao Ding, Clark M. Stanford, and Ibrahim T. Ozbolat. "Surface Micro-Scale Patterning for Biomedical Implant Material of Pure Titanium via High Energy Pulse Laser Peening." In ASME 2014 International Manufacturing Science and Engineering Conference collocated with the JSME 2014 International Conference on Materials and Processing and the 42nd North American Manufacturing Research Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/msec2014-4181.
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Pure titanium (commercial pure cpTi) is an ideal dental implant material without the leeching of toxic alloy elements. Evidence has shown that unsmooth implant surface topologies may contribute to the osteoblast differentiation in human mesenchymal pre-osteoblastic cells, which is helpful to avoid long-term peri-abutment inflammation issues for the dental implant therapy with transcutaneous devices. Studies have been conducted on the grit blasted, acid etched, or uni-directional grooved Ti surface. However, for these existing approaches, the surface quality is difficult to control or may even damage the implant. A novel idea has been studied in which more complex two-dimensional (2D) patterns can be imprinted into the dental implant material of cpTi by high energy pulse laser peening (HEPLP). The strong shock wave generated by HEPLP press a stainless steel grid, used as a stamp, on Ti foils to imprint a 2D pattern. In this study, the multiple grid patterns and grid sizes were applied to test the cell’s favor. The HEPLP induced shock wave pressure profile and history were simulated by a 2D multi-physics hydrodynamic numerical analysis for a better understanding of this technique. Then, the cell culture tests were conducted with the patterned surface to investigate the contribution of these 2D patterns, with the control tests of the other existing implant surface topography forming approaches.
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Guzman, Marco Cespedes, Scott Jason Ozirny, and Douglas Grant Smith. "Record Length Chrome Liner Run Using Innovative, Low-Marking, Non-Ferrous Dies on a Mechanical Casing Running Tool." In SPE/IADC Middle East Drilling Technology Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/202162-ms.
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Abstract Abu Dhabi National Oil Company (ADNOC) has steadily advanced toward the use of a casing running tool (CRT) vs. conventional casing running methods to improve efficiency and safety. This advancement focused mainly on 9 ⅝ in to 20 in diameter casing and utilized internal grip tools. Recently they have searched for an external-grip CRT system that would allow them to effectively run the smaller diameter liners of both ferrous and chrome (Cr) materials, especially in the extended reach drilling (ERD) wells with maximum reservoir contact (MRC). For 20 years CRT companies manufactured tools with gripping dies that could efficiently run ferrous material liners. Development of gripping mechanisms which can effectively run corrosion resistant alloy (CRA) materials has been met with varying success. Some of the challenges are to manufacture gripping dies from non-ferrous materials that will not contaminate the CRA liner and develop a gripping pattern that does not mark the CRA liner more than is accepted by API 5CRA industry standards, but maintain effective gripping force. In addition to hoisting and making up the string with no slippage it needs to perform fluid circulation at 3,000 psi. Until recently the liners were typically run in a conventional method using power-tongs. One of the tools chosen for the trial runs was a well-proven, external-grip mechanical CRT designed specifically for smaller diameter casing and liners. It has a 500-ton hoist capacity and a 5,000 psi circulation rating and was packaged with a combination float and cushion tool and a wireless torque turn sub. Dies had been designed to meet the non-contamination and acceptable marking criteria previously mentioned and would be compatible with liners possessing as much as 25% Cr. The dies had been extensively lab-tested, including heavy pull tests and torque application tests, but had not previously been used in field applications. The ERD-MRC well chosen for this trial was planned to have a record length of 6 ⅝ in, 24 ppf, 13% Cr liner with a wedge thread premium connection. In addition to not contaminating the liner, ADNOC expected an average running speed in joints per hour equivalent to the conventional casing running methods and a reduction in time during circulations. The result of the trial was 589 connections (25,035 ft liner length) successfully run with an average running speed matching their expectations. The liner displayed very minimal marks and there were no issues when hoisting or torqueing the connections. In addition, there were no rejected connections during the run. This publication will review the preparation for the run, actual run details, photos of the die marks, torque graphs and conclusions expressed by the operator with recommendations for changes moving forward.
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Mayor, V. C. "Applying Traction Coating to Steel Mill Rolls." In ITSC 1996, edited by C. C. Berndt. ASM International, 1996. http://dx.doi.org/10.31399/asm.cp.itsc1996p0061.
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Abstract This paper deals with the problem of feeding hot billets into roll stands for rolling into different shapes and the need to apply a traction coating to the roll surface at the passes so that the rolls grip the hot billet. Steel mills have tried different methods over the years to make the roll surface at the passes rough, from throwing a shovelful of sand as the billet is entering the pass to knurling and embossing a rough pattern on the passes with a pepper chisel. Some mills have tried to use sand blasting on the rolls as the billet is passing through and thus ruining the bearings. The process used for this paper is spraying a 0.006" to 0.008" thick coating on the passes with Bondrite, an 80-20 Nickel Aluminum composite wire manufactured by us. The application of this coating is extremely easy and fast. The only preparation before spraying is to clean the roll surface with a good solvent that does not leave any residue. Bondrite has a very high bondstrength and bonds to the clean smooth surface of the rolls with enough bondstrength to impart a rough traction coating on the passes.
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Nassar, Sayed A., and Ali A. Alkelani. "Elastic Interaction Between Fasteners in Gasketed Bolted Joints." In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71576.
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An experimental study is presented in order to determine the effect of several parameters on the elastic interaction between various fasteners in a gasketed joint. Parameters include the gasket thickness, bolt spacing, tightening sequence, fastener grip length, and the level of fastener preload. The joint is made of two steel flanges with a Styrene Butadiene Rubber gasket of various thicknesses. The joint is fastened together using 1/2” - 13 SAE Grade 8 fasteners that are specially instrumented to measure the initial preload and the residual tension in each fastener. Four different gasket thicknesses are considered, namely, 1/16”, 1/8”, 3/16”, and 1/4”. For the same bolt circle of the flange, bolt spacing is varied by using different number of bolts; spacing that corresponds to using three, five, or seven bolts are considered in this study. The effect of the tightening sequence is studied by using sequential bolt tightening, star pattern, and simultaneous tightening. Bolt tightening is accomplished by using either an electric digital torque wrench with various control options, or a production-size multiple spindle fastening system that is capable of simultaneous tightening of all fasteners using torque, torque-turn, or torque-to-yield control of each fastener.
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Blaser, Peter J., Dale M. Snider, Ken A. Williams, Alan E. Cook, and Mark Hoover. "Process Modeling: Lost-Foam Pattern Filling." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60483.
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A transient, three-dimensional, multi-phase particle-in-cell approach is used to solve for the flow of polystyrene beads in complex three dimensional geometries which represent patterns used for lost-foam casting. The numerical method solves the gas conservation equations on an Eulerian grid and the motion of polystyrene beads is calculated in a Lagrangian frame of reference. The true particle size distribution is modeled, and the particle flow ranges from dilute to close-pack. Predicted fill behavior is compared to experimentally blown patterns using colored beads and to the measured transient filling of a pattern. The colored beads show a complex fill pattern which is calculated well by the numerical method. The transient calculation compares very well with measured video data, and the particle motion has unique particle behavior unlike a fluid. Because of uncertainties in boundary conditions in production lost-foam tooling, the sensitivity of lost-foam pattern filling to boundary conditions is examined.
Reports on the topic "Grip pattern"
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Collins, Clarence O., and Tyler J. Hesser. altWIZ : A System for Satellite Radar Altimeter Evaluation of Modeled Wave Heights. Engineer Research and Development Center (U.S.), February 2021. http://dx.doi.org/10.21079/11681/39699.
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This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the design and implementation of a wave model evaluation system, altWIZ, which uses wave height observations from operational satellite radar altimeters. The altWIZ system utilizes two recently released altimeter databases: Ribal and Young (2019) and European Space Agency Sea State Climate Change Initiative v.1.1 level 2 (Dodet et al. 2020). The system facilitates model evaluation against 1 Hz1 altimeter data or a product created by averaging altimeter data in space and time around model grid points. The system allows, for the first time, quantitative analysis of spatial model errors within the U.S. Army Corps of Engineers (USACE) Wave Information Study (WIS) 30+ year hindcast for coastal United States. The system is demonstrated on the WIS 2017 Atlantic hindcast, using a 1/2° basin scale grid and a 1/4° regional grid of the East Coast. Consistent spatial patterns of increased bias and root-mean-square-error are exposed. Seasonal strengthening and weakening of these spatial patterns are found, related to the seasonal variation of wave energy. Some model errors correspond to areas known for high currents, and thus wave-current interaction. In conjunction with the model comparison, additional functions for pairing altimeter measurements with buoy data and storm tracks have been built. Appendices give information on the code access (Appendix I), organization and files (Appendix II), example usage (Appendix III), and demonstrating options (Appendix IV).
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Brenkert, A. L., R. J. Andres, G. Marland, I. Fung, and E. Matthews. Geographic patterns of carbon dioxide emissions from fossil-fuel burning, hydraulic cement production, and gas flaring on a one degree by one degree grid cell basis: 1950 to 1990. Office of Scientific and Technical Information (OSTI), March 1997. http://dx.doi.org/10.2172/666249.
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Dasberg, Shmuel, Jan W. Hopmans, Larry J. Schwankl, and Dani Or. Drip Irrigation Management by TDR Monitoring of Soil Water and Solute Distribution. United States Department of Agriculture, August 1993. http://dx.doi.org/10.32747/1993.7568095.bard.
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Drip irrigation has the potential of high water use efficiency, but actual water measurement is difficult because of the limited wetted volume. Two long-term experiments in orchards in Israel and in California and several field crop studies supported by this project have demonstrated the feasibility of precise monitoring of soil water distribution for drip irrigation in spite of the limited soil wetting. Time Domain Reflectometry (TDR) enables in situ measurement of soil water content of well defined small volumes. Several approaches were tried in monitoring the soil water balance in the field during drip irrigation. These also facilitated the estimation of water uptake: 1. The use of multilevel moisture probe TDR system. This approach proved to be of limited value because of the extremely small diameter of measurement. 2. The placement of 20 cm long TDR probes at predetermined distances from the drippers in citrus orchards. 3. Heavy instrumentation with neutron scattering access tubes and tensiometers of a single drip irrigated almond tree. 4. High resolution spatial and temporal measurements (0.1m x 0.1m grid) of water content by TDR in corn irrigated by surface and subsurface drip. The latter approach was accompanied by parametric modelling of water uptake intensity patterns by corn roots and superimposed with analytical solutions for water flow from point and line sources. All this lead to general and physically based suggestions for the placement of soil water sensors for scheduling drip irrigation.
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Ruiz, Pablo, Craig Perry, Alejando Garcia, Magali Guichardot, Michael Foguer, Joseph Ingram, Michelle Prats, Carlos Pulido, Robert Shamblin, and Kevin Whelan. The Everglades National Park and Big Cypress National Preserve vegetation mapping project: Interim report—Northwest Coastal Everglades (Region 4), Everglades National Park (revised with costs). National Park Service, November 2020. http://dx.doi.org/10.36967/nrr-2279586.
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The Everglades National Park and Big Cypress National Preserve vegetation mapping project is part of the Comprehensive Everglades Restoration Plan (CERP). It is a cooperative effort between the South Florida Water Management District (SFWMD), the United States Army Corps of Engineers (USACE), and the National Park Service’s (NPS) Vegetation Mapping Inventory Program (VMI). The goal of this project is to produce a spatially and thematically accurate vegetation map of Everglades National Park and Big Cypress National Preserve prior to the completion of restoration efforts associated with CERP. This spatial product will serve as a record of baseline vegetation conditions for the purpose of: (1) documenting changes to the spatial extent, pattern, and proportion of plant communities within these two federally-managed units as they respond to hydrologic modifications resulting from the implementation of the CERP; and (2) providing vegetation and land-cover information to NPS park managers and scientists for use in park management, resource management, research, and monitoring. This mapping project covers an area of approximately 7,400 square kilometers (1.84 million acres [ac]) and consists of seven mapping regions: four regions in Everglades National Park, Regions 1–4, and three in Big Cypress National Preserve, Regions 5–7. The report focuses on the mapping effort associated with the Northwest Coastal Everglades (NWCE), Region 4 , in Everglades National Park. The NWCE encompasses a total area of 1,278 square kilometers (493.7 square miles [sq mi], or 315,955 ac) and is geographically located to the south of Big Cypress National Preserve, west of Shark River Slough (Region 1), and north of the Southwest Coastal Everglades (Region 3). Photo-interpretation was performed by superimposing a 50 × 50-meter (164 × 164-feet [ft] or 0.25 hectare [0.61 ac]) grid cell vector matrix over stereoscopic, 30 centimeters (11.8 inches) spatial resolution, color-infrared aerial imagery on a digital photogrammetric workstation. Photo-interpreters identified the dominant community in each cell by applying majority-rule algorithms, recognizing community-specific spectral signatures, and referencing an extensive ground-truth database. The dominant vegetation community within each grid cell was classified using a hierarchical classification system developed specifically for this project. Additionally, photo-interpreters categorized the absolute cover of cattail (Typha sp.) and any invasive species detected as either: Sparse (10–49%), Dominant (50–89%), or Monotypic (90–100%). A total of 178 thematic classes were used to map the NWCE. The most common vegetation classes are Mixed Mangrove Forest-Mixed and Transitional Bayhead Shrubland. These two communities accounted for about 10%, each, of the mapping area. Other notable classes include Short Sawgrass Marsh-Dense (8.1% of the map area), Mixed Graminoid Freshwater Marsh (4.7% of the map area), and Black Mangrove Forest (4.5% of the map area). The NWCE vegetation map has a thematic class accuracy of 88.4% with a lower 90th Percentile Confidence Interval of 84.5%.
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Anderson, Gerald L., and Kalman Peleg. Precision Cropping by Remotely Sensed Prorotype Plots and Calibration in the Complex Domain. United States Department of Agriculture, December 2002. http://dx.doi.org/10.32747/2002.7585193.bard.
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This research report describes a methodology whereby multi-spectral and hyperspectral imagery from remote sensing, is used for deriving predicted field maps of selected plant growth attributes which are required for precision cropping. A major task in precision cropping is to establish areas of the field that differ from the rest of the field and share a common characteristic. Yield distribution f maps can be prepared by yield monitors, which are available for some harvester types. Other field attributes of interest in precision cropping, e.g. soil properties, leaf Nitrate, biomass etc. are obtained by manual sampling of the filed in a grid pattern. Maps of various field attributes are then prepared from these samples by the "Inverse Distance" interpolation method or by Kriging. An improved interpolation method was developed which is based on minimizing the overall curvature of the resulting map. Such maps are the ground truth reference, used for training the algorithm that generates the predicted field maps from remote sensing imagery. Both the reference and the predicted maps are stratified into "Prototype Plots", e.g. 15xl5 blocks of 2m pixels whereby the block size is 30x30m. This averaging reduces the datasets to manageable size and significantly improves the typically poor repeatability of remote sensing imaging systems. In the first two years of the project we used the Normalized Difference Vegetation Index (NDVI), for generating predicted yield maps of sugar beets and com. The NDVI was computed from image cubes of three spectral bands, generated by an optically filtered three camera video imaging system. A two dimensional FFT based regression model Y=f(X), was used wherein Y was the reference map and X=NDVI was the predictor. The FFT regression method applies the "Wavelet Based", "Pixel Block" and "Image Rotation" transforms to the reference and remote images, prior to the Fast - Fourier Transform (FFT) Regression method with the "Phase Lock" option. A complex domain based map Yfft is derived by least squares minimization between the amplitude matrices of X and Y, via the 2D FFT. For one time predictions, the phase matrix of Y is combined with the amplitude matrix ofYfft, whereby an improved predicted map Yplock is formed. Usually, the residuals of Y plock versus Y are about half of the values of Yfft versus Y. For long term predictions, the phase matrix of a "field mask" is combined with the amplitude matrices of the reference image Y and the predicted image Yfft. The field mask is a binary image of a pre-selected region of interest in X and Y. The resultant maps Ypref and Ypred aremodified versions of Y and Yfft respectively. The residuals of Ypred versus Ypref are even lower than the residuals of Yplock versus Y. The maps, Ypref and Ypred represent a close consensus of two independent imaging methods which "view" the same target. In the last two years of the project our remote sensing capability was expanded by addition of a CASI II airborne hyperspectral imaging system and an ASD hyperspectral radiometer. Unfortunately, the cross-noice and poor repeatability problem we had in multi-spectral imaging was exasperated in hyperspectral imaging. We have been able to overcome this problem by over-flying each field twice in rapid succession and developing the Repeatability Index (RI). The RI quantifies the repeatability of each spectral band in the hyperspectral image cube. Thereby, it is possible to select the bands of higher repeatability for inclusion in the prediction model while bands of low repeatability are excluded. Further segregation of high and low repeatability bands takes place in the prediction model algorithm, which is based on a combination of a "Genetic Algorithm" and Partial Least Squares", (PLS-GA). In summary, modus operandi was developed, for deriving important plant growth attribute maps (yield, leaf nitrate, biomass and sugar percent in beets), from remote sensing imagery, with sufficient accuracy for precision cropping applications. This achievement is remarkable, given the inherently high cross-noice between the reference and remote imagery as well as the highly non-repeatable nature of remote sensing systems. The above methodologies may be readily adopted by commercial companies, which specialize in proving remotely sensed data to farmers.