scholarly journals Characteristic of Motor Control in Three-Dimensional Circular Tracking Movements during Monocular Vision

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Woong Choi ◽  
Liang Li ◽  
Jongho Lee
Keyword(s):  
Motor Control ◽  
Three Dimensional ◽  
Monocular Vision ◽  
Polar Coordinates ◽  
Depth Information ◽  
Visually Guided ◽  
The Subject ◽  
Tracking Movements ◽  
The Difference ◽  
Tracking Movement

Analysis of visually guided tracking movements is an important component of understanding human visuomotor control system. The aim of our study was to investigate the effects of different target speeds and different circular tracking planes, which provide different visual feedback of depth information, on temporal and spatial tracking accuracy. In this study, we analyze motor control characteristic of circular tracking movements during monocular vision in three-dimensional space using a virtual reality system. Three parameters in polar coordinates were analyzed: ΔR, the difference in the distance from the fixed pole; Δθ, the difference in the position angle; and Δω, the difference in the angular velocity. We compare the accuracy of visually guided circular tracking movements during monocular vision in two conditions: (1) movement in the frontal plane relative to the subject that requires less depth information and (2) movement in the sagittal plane relative to the subject that requires more depth information. We also examine differences in motor control at four different target speeds. The results show that depth information affects both spatial and temporal accuracy of circular tracking movement, whereas target speed only affects temporal accuracy of circular tracking movement. This suggests that different strategies of feedforward and feedback controls are performed in the tracking of movements.

scholarly journals Analysis of Three-Dimensional Circular Tracking Movements Based on Temporo-Spatial Parameters in Polar Coordinates

2020 ◽  
Vol 10 (2) ◽  
pp. 621 ◽  
Author(s):  
Woong Choi ◽  
Jongho Lee ◽  
Liang Li
Keyword(s):  
Motor Control ◽  
Sagittal Plane ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Polar Coordinates ◽  
Target Velocity ◽  
Healthy Human ◽  
3D Space ◽  
Tracking Movements

Motor control characteristics of the human visuomotor control system need to be analyzed in the three-dimensional (3D) space to study and imitate human movements. In this paper, we examined circular tracking movements on two planes in 3D space from a motor control perspective based on three temporospatial parameters in polar coordinates. Sixteen healthy human subjects participated in this study and performed circular target tracking movements rotating at 0.125, 0.25, 0.5, and 0.75 Hz in the frontal or sagittal planes in three-dimensional space. The results showed that two temporal parameter errors on each plane were proportional to the change in the target velocity. Furthermore, frontal plane circular tracking errors without depth for a spatial parameter were lower than those for sagittal plane circular tracking with depth. The experimental protocol and data analysis allowed us to analyze the motor control characteristics temporospatially for circular tracking movement with various depths and speeds in the 3D VR space.

scholarly journals The role of binocular vision in walking

2009 ◽  
Vol 26 (1) ◽  
pp. 73-80 ◽  
Author(s):  
MARY HAYHOE ◽  
BARBARA GILLAM ◽  
KELLY CHAJKA ◽  
ELIA VECELLIO
Keyword(s):  
Binocular Vision ◽  
Monocular Vision ◽  
Stereoscopic Vision ◽  
Eye Position ◽  
Visually Guided ◽  
Extensive Investigation ◽  
Foot Placement ◽  
Walking Performance ◽  
The Difference

AbstractDespite the extensive investigation of binocular and stereoscopic vision, relatively little is known about its importance in natural visually guided behavior. In this paper, we explored the role of binocular vision when walking over and around obstacles. We monitored eye position during the task as an indicator of the difference between monocular and binocular performances. We found that binocular vision clearly facilitates walking performance. Walkers were slowed by about 10% in monocular vision and raised their foot higher when stepping over obstacles. Although the location and sequence of the fixations did not change in monocular vision, the timing of the fixations relative to the actions was different. Subjects spent proportionately more time fixating the obstacles and fixated longer while guiding foot placement near an obstacle. The data are consistent with greater uncertainty in monocular vision, leading to a greater reliance on feedback in the control of the movements.

The Transparent Body

2030 ◽  
2010 ◽  
Author(s):  
Rutger van Santen ◽  
Djan Khoe ◽  
Bram Vermeer
Keyword(s):  
Early Stage ◽  
Three Dimensional ◽  
The United States ◽  
The Body ◽  
Western World ◽  
Depth Information ◽  
Tennis Ball ◽  
Dimensional Image ◽  
Life Threatening ◽  
The Difference

The “easy” diseases have pretty much been beaten in the Western world, leaving doctors to contend with the more complex illnesses that stealthily overrun the body. Two-thirds of the deaths in the United States are now attributable to cancer or coronary disease. By the time these conditions manifest themselves, it’s often too late to intervene. Treatment is only likely to succeed if early signs of cancerous growth or clogging arteries can be detected. A tumor measuring a few millimeters across is plainly less threatening than one the size of a tennis ball, not least because there is less risk of metastasis at an early stage. The focus is therefore on enhancing rapid diagnosis, which in turn means improving medical imaging. Eighty percent of all diagnoses are based on images. Yet many small but life-threatening physical processes are still missed by the scanners, echographs, and other devices that peer inside our bodies. Growths measuring less than a centimeter tend to be overlooked, so scientists are constantly working on techniques capable of offering a more detailed internal picture. Breakthroughs in imaging technology can mean the difference between life and death. They’ll enable us to intervene sooner, boosting the patient’s survival chances. Little more than a generation ago, X-rays were the only means we had of looking inside the human body. The images they produce are flat, however, and lacking in depth information, which can make them hard to interpret. An ingenious technique was therefore devised in the 1970s that allowed a single three-dimensional image to be created by combining a series of X-ray photographs. The CT (computerized tomography) scan was the first technique to produce a genuine three-dimensional image of our insides. Doctors could now tell, for instance, whether an abnormality was located on top of a bone or beneath it. Several other techniques for producing three-dimensional images of the body have since become available, some of which require patients to be injected with a contrast agent to highlight specific parts of the body.

Absolute Depth Measurement of Objects Based on Monocular Vision

2020 ◽  
Vol 29 (07n08) ◽  
pp. 2040011
Author(s):  
Zhongsheng Wang ◽  
Yufeng Lai ◽  
Sen Yang ◽  
Jiaqiong Gao
Keyword(s):  
Measurement Method ◽  
Three Dimensional ◽  
Target Object ◽  
Measurement Methods ◽  
Monocular Vision ◽  
Depth Information ◽  
Depth Measurement ◽  
Comparison Results ◽  
Feature Information ◽  
The Absolute

With the continuous development of computer vision technology and the continuous upgrading of digital imaging equipment, image depth measurement method is widely used in the fields of intelligent robotics, traffic assistance, three-dimensional modeling and three dimensional video production. The following are the drawbacks of the traditional depth information measurement method: the operation is complex, the cost is high, and the measuring equipment occupies a large space and the load. In this paper, based on the Harris-SIFT corner detection algorithm, a technique is proposed to measure the absolute depth information of the object in the image using monocular vision. First of all, after the monocular camera is used to obtain the image of the target object, the image segmentation algorithm based on the LBF model is used to preprocess the image. Then, Harris algorithm in multi-scale space and SFIT algorithm to reconstruct feature descriptors are used to extract feature information in the image. Finally, by comparing the feature information between image groups, the depth information of target object is calculated by using the formula of convex hull principle and camera imaging principle. The test platform is applied to carry out measurement tests for different depth measurement methods, and the actual depth data and measurement data of the target object are compared, so as to evaluate the accuracy of the measurement method. The comparison results show that the error rate between the actual distance and the measured distance is less than 3.5%, which can accurately measure the absolute depth of the object in static and short distance, and is superior to other measurement methods.

Defocus ramp correction in spot-scan imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 130-131
Author(s):  
Kenneth H. Downing
Keyword(s):  
Computer Control ◽  
Three Dimensional ◽  
Sufficient Accuracy ◽  
Objective Lens ◽  
Electron Crystallography ◽  
Contrast Transfer Function ◽  
Tilt Axis ◽  
Specimen Height ◽  
The Difference ◽  
Envelope Functions

Three-dimensional structures of a number of samples have been determined by electron crystallography. The procedures used in this work include recording images of fairly large areas of a specimen at high tilt angles. There is then a large defocus ramp across the image, and parts of the image are far out of focus. In the regions where the defocus is large, the contrast transfer function (CTF) varies rapidly across the image, especially at high resolution. Not only is the CTF then difficult to determine with sufficient accuracy to correct properly, but the image contrast is reduced by envelope functions which tend toward a low value at high defocus.We have combined computer control of the electron microscope with spot-scan imaging in order to eliminate most of the defocus ramp and its effects in the images of tilted specimens. In recording the spot-scan image, the beam is scanned along rows that are parallel to the tilt axis, so that along each row of spots the focus is constant. Between scan rows, the objective lens current is changed to correct for the difference in specimen height from one scan to the next.

Learning Language Levels in Students Accurate with a History Academic Achievement History

2017 ◽  
Vol 1 (2) ◽  
pp. 137
Author(s):  
Noorlela Binti Noordin ◽  
Abdul Razaq Ahmad ◽  
Anuar Ahmad
Keyword(s):  
Academic Achievement ◽  
Statistical Inference ◽  
Quantitative Data ◽  
Quantitative Methods ◽  
Descriptive Statistics ◽  
Language Test ◽  
The Subject ◽  
The Difference ◽  
Learning Language ◽  
The Relationship

This study was aimed to evaluate the Malay proficiency among students in Form Two especially non-Malay students and its relationship to academic achievement History. To achieve the purpose of the study there are two objectives, the first is to look at the difference between mean of Malay Language test influences min of academic achievement of History subject among non-Malay students in Form Two and the second is the relationship between the level of Malay proficiency and their academic achievement for History. This study used quantitative methods, which involved 100 people of Form Two non-Malay students in one of the schools in Klang, Selangor. This study used quantitative data were analyzed using descriptive statistics and statistical inference with IBM SPSS Statistics v22 software. This study found that there was a relationship between the proficiency of Malay language among non-Malay students with achievements in the subject of History. The implications of this study are discussed in this article.

The Idea of a Meaningful Synthesis of Marxist and Non-Marxist Systems of Political Economy as a Mirror of Intellectual Turmoil (About V.T. Ryazanov’s Book «Modern Political Economy: Prospects of Neo-Marxist Synthesis»)

2019 ◽  
pp. 74-98
Author(s):  
A.B. Lyubinin
Keyword(s):  
Economic Theory ◽  
Political Economy ◽  
Economic Status ◽  
Economic Science ◽  
Objective Reality ◽  
Commodity Production ◽  
Subjective Assessments ◽  
The Subject ◽  
The Difference ◽  
Political Economic

Review of the monograph indicated in the subtitle V.T. Ryazanov. The reviewer is critical of the position of the author of the book, believing that it is possible and even necessary (to increase the effectiveness of General economic theory and bring it closer to practice) substantial (and not just formal-conventional) synthesis of the Marxist system of political economy with its non-Marxist systems. The article emphasizes the difference between the subject and the method of the classical, including Marxist, school of political economy with its characteristic objective perception of the subject from the neoclassical school with its reduction of objective reality to subjective assessments; this excludes their meaningful synthesis as part of a single «modern political economy». V.T. Ryazanov’s interpretation of commodity production in the economic system of «Capital» of K. Marx as a purely mental abstraction, in fact — a fiction, myth is also counter-argued. On the issue of identification of the discipline «national economy», the reviewer, unlike the author of the book, takes the position that it is a concrete economic science that does not have a political economic status.

ISLAMIC COMMERCIAL LAW

1997 ◽  
Vol 14 (3) ◽  
pp. 17-37
Author(s):  
Mohammad Hashim Kamali
Keyword(s):  
Risk Reduction ◽  
Basic Question ◽  
Depth Information ◽  
Commercial Law ◽  
Other Hand ◽  
Legal Perspective ◽  
Financial Speculation ◽  
The Subject ◽  
Options Trading

This essay is presented in two sections. Section one is devoted to amarket analysis of options, and section two to a Shari'ah perspective onoptions trading. There is no real shortage of information in the operationalprocedures of options and the various ways in which options areutilized as trading vehicles and hedging and risk-reduction devices. Onthe other hand, there is a shortage of in-depth information analyzingoptions trading from the perspective of the Shari'ah. The second part ofthis essay is tentative, in part because certain aspects of the issue needfurther development and research. The literature on the subject is in itsearly stages and has not reached a stage where consensus on issues canbe identified. This is borne out perhaps by the divided opinion that wehave at present over the basic question of the validity or nonvalidity ofoptions from an Islamic legal perspective. I shall review these twoopposing currents of opinion in due course. Suffice it here to note thatthis presentation does not seek to advocate the validity of those varietiesof options which either directly or indirectly proceed on the charging offixed interest to accounts. This may be said to be one of the distinctivefeatures of the Shari'ah perspective on options-just as it is of all varietiesof commercial transactions in Islamic law.My review of the mechanics of options trading in the first section ofthis essay broadly indicates that options trading does not proceed oncharging of fixed interest, nor does it involve unwarranted risk takingand uncertainty (gharur). Options trading has a logic of its own, whichis dominated by the idea of risk reduction and hedging against excessivelylarge positions in its underlying assets. From the perspective ofIslamic law this aspect of options is attractive and hence, from this perspectiveI make the case for the legality of options. I may also add herein passing that options trading cannot be equated with gambling or overindulgencein financial speculation. as it is basically designed to ...

Geological Field Sketches and Illustrations

2019 ◽  
Author(s):  
Matthew J. Genge
Keyword(s):  
Cross Sections ◽  
Earth Science ◽  
Three Dimensional ◽  
Worked Examples ◽  
Scientific Publications ◽  
Thin Sections ◽  
Geological Features ◽  
Different Types ◽  
The Subject

Drawings, illustrations, and field sketches play an important role in Earth Science since they are used to record field observations, develop interpretations, and communicate results in reports and scientific publications. Drawing geology in the field furthermore facilitates observation and maximizes the value of fieldwork. Every geologist, whether a student, academic, professional, or amateur enthusiast, will benefit from the ability to draw geological features accurately. This book describes how and what to draw in geology. Essential drawing techniques, together with practical advice in creating high quality diagrams, are described the opening chapters. How to draw different types of geology, including faults, folds, metamorphic rocks, sedimentary rocks, igneous rocks, and fossils, are the subjects of separate chapters, and include descriptions of what are the important features to draw and describe. Different types of sketch, such as drawings of three-dimensional outcrops, landscapes, thin-sections, and hand-specimens of rocks, crystals, and minerals, are discussed. The methods used to create technical diagrams such as geological maps and cross-sections are also covered. Finally, modern techniques in the acquisition and recording of field data, including photogrammetry and aerial surveys, and digital methods of illustration, are the subject of the final chapter of the book. Throughout, worked examples of field sketches and illustrations are provided as well as descriptions of the common mistakes to be avoided.

Rhythm

2018 ◽  
Author(s):  
Lexi Eikelboom
Keyword(s):  
Social Sciences ◽  
Twentieth Century ◽  
Human Existence ◽  
Embodied Experience ◽  
Giorgio Agamben ◽  
The Social ◽  
Contemporary Philosopher ◽  
The Subject ◽  
The Difference ◽  
Theoretical Category

This book argues that, as a pervasive dimension of human existence with theological implications, rhythm ought to be considered a category of theological significance. Philosophers and theologians have drawn on rhythm—patterned movements of repetition and variation—to describe reality, however, the ways in which rhythm is used and understood differ based on a variety of metaphysical commitments with varying theological implications. This book brings those implications into the open, using resources from phenomenology, prosody, and the social sciences to analyse and evaluate uses of rhythm in metaphysical and theological accounts of reality. The analysis relies on a distinction from prosody between a synchronic approach to rhythm—observing the whole at once and considering how various dimensions of a rhythm hold together harmoniously—and a diachronic approach—focusing on the ways in which time unfolds as the subject experiences it. The text engages with the twentieth-century Jesuit theologian Erich Przywara alongside thinkers as diverse as Augustine and the contemporary philosopher Giorgio Agamben, and proposes an approach to rhythm that serves the concerns of theological conversation. It demonstrates the difference that including rhythm in theological conversation makes to how we think about questions such as “what is creation?” and “what is the nature of the God–creature relationship?” from the perspective of rhythm. As a theoretical category, capable of expressing metaphysical commitments, yet shaped by the cultural rhythms in which those expressing such commitments are embedded, rhythm is particularly significant for theology as a phenomenon through which culture and embodied experience influence doctrine.

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