scholarly journals ACTIVE SEGMENTATION

2009 ◽  
Vol 06 (03) ◽  
pp. 361-386 ◽  
Author(s):  
AJAY K. MISHRA ◽  
YIANNIS ALOIMONOS
Keyword(s):  
Visual Processing ◽  
Boundary Edge ◽  
Color Intensity ◽  
Image Region ◽  
Independent Manner ◽  
Connected Set ◽  
Segmentation Framework ◽  
Real Imagery ◽  
The One ◽  
Segmentation Problem

The human visual system observes and understands a scene/image by making a series of fixations. Every "fixation point" lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the "fixation point". Segmenting the region containing the fixation is equivalent to finding the enclosing contour — a connected set of boundary edge fragments in the edge map of the scene — around the fixation. This enclosing contour should be a depth boundary. We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. The semantic robots of the immediate future will be able to use this algorithm to automatically find objects in any environment. The capability of automatically segmenting objects in their visual field can bring the visual processing to the next level. Our approach is different from current approaches. While existing work attempts to segment the whole scene at once into many areas, we segment only one image region, specifically the one containing the fixation point. Experiments with real imagery collected by our active robot and from the known databases1 demonstrate the promise of the approach.

Effects of serial lesions of telencephalic components of the visual system in pigeons

1988 ◽  
Vol 1 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Nell M. Riley ◽  
William Hodos ◽  
Tatiana Pasternak
Keyword(s):  
Visual System ◽  
Visual Processing ◽  
Pattern Discrimination ◽  
Color Intensity ◽  
Sequence Of Events ◽  
Serial Lesion ◽  
Avian Visual System ◽  
The One ◽  
Tectofugal Pathway ◽  
Made In

AbstractA serial-lesion technique was used to investigate interactions in visual processing between telencephalic components of the pigeon visual system. Pigeons were trained to discriminate pairs of stimuli that differed in color, intensity or pattern. After mastering the discrimination tasks, they were assigned to one of three groups. The first group (WI-EII) received lesions of the visual Wulst and were retested. After the discrimination tasks were again mastered, a second set of lesions was made, this time in the ectostriatum. The birds were tested once again after the second surgery. The second group (EI-WII), underwent the same sequence of events except that the order of the lesions was reversed. In the third group (E + W), lesions of both the visual Wulst and ectostriatum were made in a single operation, followed by retesting. The performance after the first lesion of the subjects in each of the two-stage lesion groups was typical of performance after such lesions; i.e. the birds with visual-Wulst lesions showed little or no impairment on any of the tasks, whereas the pigeons with ectostriatum lesions showed considerable deficits in intensity and pattern discrimination, which diminished after prolonged retraining. In contrast, the pigeons in the one-stage group (E + W) showed profound deficits that appeared to be permanent. The performance after the second operation of the WI-EII group was the same as that of pigeons with lesions of ectostriatum alone; i.e. destruction of ectostriatum first or second resulted in the same duration of impairment. The performance of the EI-WII group after its visual Wulst lesion, however, was similar to that observed in the E + W group. The results are interpreted as a reflection of parallel processing within the avian visual system; i.e. the presence of an intact tectofugal pathway may mask the effects of thalamofugal pathway interruption.

On the Pinna Illusion

2017 ◽  
Author(s):  
Baingio Pinna
Keyword(s):  
Visual Processing ◽  
Visual Illusion ◽  
Illusory Motion ◽  
Local Motion ◽  
Rotation Effect ◽  
The Gaze ◽  
Motion Signal ◽  
First Case ◽  
Counter Rotation ◽  
The One

The Pinna illusion is the first case of visual illusion showing a rotating motion phenomenon. Squares, arranged in two concentric rings, show a strong counter-rotation effect. The inner ring of the squares appears to rotate counterclockwise and the outer ring clockwise when the observer’s head is slowly moved toward the figure while the gaze is kept fixed in the center of the stimulus pattern. The direction of rotation is reversed when the observer’s head moves away from the stimulus. The speed of the illusory rotation is proportional to the one of the motion imparted by the observer. While the way each individual check receives a local illusory motion signal can be explained by the response of direction-selective neurons at the earliest cortical stage of visual processing, the whole illusory rotational motion can be thought to be sensed by the higher cortical area, which collates all the signals provided by the local motion checks.

scholarly journals 4D N = 1 SYM supercurrent on the lattice in terms of the gradient flow

2018 ◽  
Vol 175 ◽  
pp. 11014
Author(s):  
Kenji Hieda ◽  
Aya Kasai ◽  
Hiroki Makino ◽  
Hiroshi Suzuki
Keyword(s):  
Gradient Flow ◽  
Independent Manner ◽  
Yang Mills ◽  
Loop Level ◽  
Lattice Regularization ◽  
The One ◽  
Noether Current ◽  
Super Yang Mills Theory

The gradient flow [1–5] gives rise to a versatile method to construct renor-malized composite operators in a regularization-independent manner. By adopting this method, the authors of Refs. [6–9] obtained the expression of Noether currents on the lattice in the cases where the associated symmetries are broken by lattice regularization. We apply the same method to the Noether current associated with supersymmetry, i.e., the supercurrent. We consider the 4D N = 1 super Yang–Mills theory and calculate the renormalized supercurrent in the one-loop level in the Wess–Zumino gauge. We then re-express this supercurrent in terms of the flowed gauge and flowed gaugino fields [10].

scholarly journals Does an increase in water color intensity affect the lake trophic status and phytoplankton metrics?

2018 ◽  
pp. 46
Author(s):  
Tomasz Lenard ◽  
Wojciech Ejankowski ◽  
Małgorzata Poniewozik
Keyword(s):  
Trophic Status ◽  
Ecological Status ◽  
Phosphorus Concentration ◽  
Trophic State Index ◽  
Color Intensity ◽  
Water Color ◽  
High Precipitation Events ◽  
High Precipitation ◽  
The One ◽  
Good Ecological Status

During the 11-year period covered by this study (2003–2013), high precipitation events increased the water level in the deep hardwater of Lake Rogóźno (Eastern Poland), causing its water to become browner. We investigated the effect of a change in water color on the physical, chemical, and biological parameters of the lake. The concentration of total phosphorus and nitrogen decreased, whereas the total phytoplankton biomass, coupled with a high biomass of flagellate species, increased, with the increase in water color intensity. Such changes had an effect on the determination of ecological status, based on selected phytoplankton metrics (i.e., Polish, German, and Estonian) as well as the trophic status of Lake Rogóźno. The decrease of phosphorus concentration associated with an increase in water color intensity improved the trophic status of the lake based on Carlson's Trophic State Index. The changes in the phytoplankton community caused the deterioration of the ecological status of the lake when using the Polish and German indices adopted for clear water lakes. The use of the Estonian index, which is adapted to colored lakes, suggested that, despite the increase in water color intensity, the good ecological status of the lake was maintained or even improved. Our findings suggest that, in the event of a transformation like the one that occurred in the lake studied here, the use of only one index, adapted by state environmental monitoring programs in individual European countries, may be insufficient for the appropriate assessment of the ecological status of European lakes.

scholarly journals Assessment of Breathing Parameters Using an Inertial Measurement Unit (IMU)-Based System

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 88 ◽  
Author(s):  
Ambra Cesareo ◽  
Ylenia Previtali ◽  
Emilia Biffi ◽  
Andrea Aliverti
Keyword(s):  
Inertial Sensors ◽  
Low Cost ◽  
Estimation Error ◽  
Processing Algorithm ◽  
Measurement Unit ◽  
Breathing Patterns ◽  
Independent Manner ◽  
Inertial Measurement ◽  
Optoelectronic Plethysmography ◽  
The One

Breathing frequency (fB) is an important vital sign that—if appropriately monitored—may help to predict clinical adverse events. Inertial sensors open the door to the development of low-cost, wearable, and easy-to-use breathing-monitoring systems. The present paper proposes a new posture-independent processing algorithm for breath-by-breath extraction of breathing temporal parameters from chest-wall inclination change signals measured using inertial measurement units. An important step of the processing algorithm is dimension reduction (DR) that allows the extraction of a single respiratory signal starting from 4-component quaternion data. Three different DR methods are proposed and compared in terms of accuracy of breathing temporal parameter estimation, in a group of healthy subjects, considering different breathing patterns and different postures; optoelectronic plethysmography was used as reference system. In this study, we found that the method based on PCA-fusion of the four quaternion components provided the best fB estimation performance in terms of mean absolute errors (<2 breaths/min), correlation (r > 0.963) and Bland–Altman Analysis, outperforming the other two methods, based on the selection of a single quaternion component, identified on the basis of spectral analysis; particularly, in supine position, results provided by PCA-based method were even better than those obtained with the ideal quaternion component, determined a posteriori as the one providing the minimum estimation error. The proposed algorithm and system were able to successfully reconstruct the respiration-induced movement, and to accurately determine the respiratory rate in an automatic, position-independent manner.

Symmetry-breaking bifurcation for the one-dimensional Hénon equation

2019 ◽  
Vol 21 (01) ◽  
pp. 1750097
Author(s):  
Inbo Sim ◽  
Satoshi Tanaka
Keyword(s):  
Symmetry Breaking ◽  
Bifurcation Point ◽  
Global Bifurcation ◽  
One Dimensional ◽  
Bifurcation Points ◽  
Connected Set ◽  
Hénon Equation ◽  
The One ◽  
Symmetry Breaking Bifurcation

We show the existence of a symmetry-breaking bifurcation point for the one-dimensional Hénon equation [Formula: see text] where [Formula: see text] and [Formula: see text]. Moreover, employing a variant of Rabinowitz’s global bifurcation, we obtain the unbounded connected set (the first of the alternatives about Rabinowitz’s global bifurcation), which emanates from the symmetry-breaking bifurcation point. Finally, we give an example of a bounded branch connecting two symmetry-breaking bifurcation points (the second of the alternatives about Rabinowitz’s global bifurcation) for the problem [Formula: see text] where [Formula: see text] is a specified continuous parametrization function.

scholarly journals Facial Recognition and Visual Processing as We Age: Using the Thatcher Illusion with Famous and Non-Famous Faces

2017 ◽  
Vol 9 (2) ◽  
pp. 26
Author(s):  
Richard E. Hicks ◽  
Victoria Alexander ◽  
Mark Bahr
Keyword(s):  
Visual System ◽  
Visual Processing ◽  
Age Groups ◽  
Limited Attention ◽  
Older Individuals ◽  
Younger Age ◽  
The Face ◽  
The One ◽  
Interaction With Age ◽  
Thatcher Illusion

This paper reports a study examining preferred visual processes in recognition of facial features in older vs younger age groups, using Thatcherised images of famous and non-famous people in the one study. The aims were to determine whether decline in visual system processing occurs increasingly as we grow older, and whether there is less decline in recognition of famous (or familiar) faces. Three groups (younger, middle-old and older) made up the sample of 73 people (aged 19-82 years). Visual decline in face recognition across the age groups was assessed based on the Thatcher illusion—using four famous and four non-famous faces either with normal features or with distorted features. The faces were presented one at a time on computer screen, and participants were asked to judge whether the face was distorted (eyes and/or mouth not aligned in relation to the face); in addition, time taken to decision (latency) was also measured. Decline was found in visual processing such that older individuals gave limited attention to facial details (processing faces holistically, with detail errors) and they took longer to decide. Whether the faces were famous or not did not have significant effects on the decisions and there was no interaction with age, though famous faces were given longer attention. Our visual system processes decline as we age in that we give less attention to details and more to holistic processing and so make more errors in recognition. Implications for treatment or amelioration of the effects are discussed.

scholarly journals Perigonium color and the antioxidant capacity of cañihua (Chenopodium pallidicaule Aellen)

2021 ◽  
Vol 38 (2) ◽  
pp. 99-110
Author(s):  
Manuel Alfredo Callohuanca-Pariapaza ◽  
Evaristo Mamani-Mamani ◽  
Javier Mamani-Paredes ◽  
Ali William Canaza-Cayo
Keyword(s):  
Antioxidant Capacity ◽  
San Antonio ◽  
Flavonoid Content ◽  
Color Intensity ◽  
Light Yellow ◽  
National University ◽  
Yellow Orange ◽  
The One ◽  
Functional Components ◽  
The Relationship

Currently, it is necessary to know the content of bioactive compounds, one of them is the antioxidant capacity of food, which has nutritional importance and functional properties, since these components are natural and play an important role in the prevention and treatment of several diseases, including cancer. Therefore, the objective of the investigation was to determine the nutritional quality and the relationship between the color intensity of the perigonium and the antioxidant capacity of the Chenopodium pallidicaule (Ch. pallidicaule). As material of study, we used four accessions of Ch. pallidicaule with perigonia of defined colors such as light yellow, orange, purple and black. We developed the physical-chemical analyzes and the grain functional components in the Agroindustrial Engineering Laboratories of the National University of Altiplano Puno, and in the Laboratory of Chromatography and Spectrometry of the San Antonio de Abad National University of Cusco. The results were submitted to Pearson's correlation analysis, and they show that the flavonoid indices with the perigonium color intensity values express significant positive correlation. In addition, the antioxidant capacity equivalent to Trolox was significantly different between the perigonium color intensities, where the accession with black perigonium turns out to be the one that reached the highest value (5g eq. Trolox/100g sample). We conclude that the color of the perigonium exhibited antioxidant capacity, which kept a direct correlation with the flavonoid content.

scholarly journals Abnormal Vision-Based Displacement Perception in Parkinson’s Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Matthew Bernardinis ◽  
S. Farokh Atashzar ◽  
Rajni V. Patel ◽  
Mandar S. Jog
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Visual Processing ◽  
De Novo ◽  
Early Stage ◽  
Absolute Measurement ◽  
Motor Disorder ◽  
Independent Manner ◽  
Graphical Tool ◽  
Wide Range

In this work, we investigate the effect of Parkinson’s disease (PD), and common corresponding therapies on vision-based perception of motion, a critical perceptual ability required for performing a wide range of activities of daily livings. While PD has been recognized as mainly a motor disorder, sensory manifestation of PD can also play a major role in the resulting disability. In this paper, for the first time, the effect of disease duration and common therapies on vision-based perception of displacement were investigated. The study is conducted in a movement-independent manner, to reject the shadowing effects and isolate the targeted perceptual disorder to the maximum possible extent. Data was collected using a computerized graphical tool on 37 PD patients [6 early-stage de novo, 25 mid-stage using levodopa therapy, six later-stage using deep brain stimulation (DBS)] and 15 control participants. Besides the absolute measurement of perception through a psychometric analysis on two tested position reference magnitudes, we also investigated the linearity in perception using Weber’s fraction. The results showed that individuals with PD displayed significant perceptual impairments compared to controls, though early-stage patients were not impaired. Mid-stage patients displayed impairments at the greater of the two tested reference magnitudes, while late-stage patients were impaired at both reference magnitudes. Levodopa and DBS use did not cause statistically significant differences in absolute displacement perception. The findings suggest abnormal visual processing in PD increasing with disease development, perhaps contributing to sensory-based impairments of PD such as bradykinesia, visuospatial deficits, and abnormal object recognition.

scholarly journals A Chimeric Respiratory Syncytial Virus Fusion Protein Functionally Replaces the F and HN Glycoproteins in Recombinant Sendai Virus

2005 ◽  
Vol 79 (16) ◽  
pp. 10467-10477 ◽  
Author(s):  
Gert Zimmer ◽  
Sascha Bossow ◽  
Larissa Kolesnikova ◽  
Matthias Hinz ◽  
Wolfgang J. Neubert ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Fusion Protein ◽  
Fusion Proteins ◽  
Reverse Genetics ◽  
Transmembrane Domain ◽  
Sendai Virus ◽  
Independent Manner ◽  
Lower Efficiency ◽  
Syncytial Virus ◽  
The One

ABSTRACT Entry of most paramyxoviruses is accomplished by separate attachment and fusion proteins that function in a cooperative manner. Because of this close interdependence, it was not possible with most paramyxoviruses to replace either of the two protagonists by envelope glycoproteins from related paramyxoviruses. By using reverse genetics of Sendai virus (SeV), we demonstrate that chimeric respiratory syncytial virus (RSV) fusion proteins containing either the cytoplasmic domain of the SeV fusion protein or in addition the transmembrane domain were efficiently incorporated into SeV particles provided the homotypic SeV-F was deleted. In the presence of SeV-F, the chimeric glycoproteins were incorporated with significantly lower efficiency, indicating that determinants in the SeV-F ectodomain exist that contribute to glycoprotein uptake. Recombinant SeV in which the homotypic fusion protein was replaced with chimeric RSV fusion protein replicated in a trypsin-independent manner and was neutralized by antibodies directed to RSV-F. However, replication of this virus also relied on the hemagglutinin-neuraminidase (HN) as pretreatment of cells with neuraminidase significantly reduced the infection rate. Finally, recombinant SeV was generated with chimeric RSV-F as the only envelope glycoprotein. This virus was not neutralized by antibodies to SeV and did not use sialic acids for attachment. It replicated more slowly than hybrid virus containing HN and produced lower virus titers. Thus, on the one hand RSV-F can mediate infection in an autonomous way while on the other hand it accepts support by a heterologous attachment protein.

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