scholarly journals On Learning Sets of Symmetric Elements (Extended Abstract)

2021 ◽  
Author(s):  
Haggai Maron ◽  
Or Litany ◽  
Gal Chechik ◽  
Ethan Fetaya
Keyword(s):  
Shape Recognition ◽  
Point Clouds ◽  
Approach To Learning ◽  
Series Of Experiments ◽  
The Common ◽  
Equivariant Functions ◽  
Siamese Networks ◽  
Universal Approximators ◽  
Learning Architectures ◽  
Learning Sets

Learning from unordered sets is a fundamental learning setup, recently attracting increasing attention. Research in this area has focused on the case where elements of the set are represented by feature vectors, and far less emphasis has been given to the common case where set elements themselves adhere to their own symmetries. That case is relevant to numerous applications, from deblurring image bursts to multi-view 3D shape recognition and reconstruction. In this paper, we present a principled approach to learning sets of general symmetric elements. We first characterize the space of linear layers that are equivariant both to element reordering and to the inherent symmetries of elements, like translation in the case of images. We further show that networks that are composed of these layers, called Deep Sets for Symmetric Elements layers (DSS), are universal approximators of both invariant and equivariant functions, and that these networks are strictly more expressive than Siamese networks. DSS layers are also straightforward to implement. Finally, we show that they improve over existing set-learning architectures in a series of experiments with images, graphs, and point clouds.

scholarly journals SPPD: A Novel Reassembly Method for 3D Terracotta Warrior Fragments Based on Fracture Surface Information

2021 ◽  
Vol 10 (8) ◽  
pp. 525
Author(s):  
Wenmin Yao ◽  
Tong Chu ◽  
Wenlong Tang ◽  
Jingyu Wang ◽  
Xin Cao ◽  
...  
Keyword(s):  
Fracture Surface ◽  
Principal Component ◽  
Point Clouds ◽  
Three Dimension ◽  
Registration Method ◽  
Series Of Experiments ◽  
Coarse To Fine ◽  
Fine Registration ◽  
Common Situation ◽  
Better Than

As one of China′s most precious cultural relics, the excavation and protection of the Terracotta Warriors pose significant challenges to archaeologists. A fairly common situation in the excavation is that the Terracotta Warriors are mostly found in the form of fragments, and manual reassembly among numerous fragments is laborious and time-consuming. This work presents a fracture-surface-based reassembling method, which is composed of SiamesePointNet, principal component analysis (PCA), and deep closest point (DCP), and is named SPPD. Firstly, SiamesePointNet is proposed to determine whether a pair of point clouds of 3D Terracotta Warrior fragments can be reassembled. Then, a coarse-to-fine registration method based on PCA and DCP is proposed to register the two fragments into a reassembled one. The above two steps iterate until the termination condition is met. A series of experiments on real-world examples are conducted, and the results demonstrate that the proposed method performs better than the conventional reassembling methods. We hope this work can provide a valuable tool for the virtual restoration of three-dimension cultural heritage artifacts.

scholarly journals Compact Laser Collimation System for Simultaneous Measurement of Five-Degree-of-Freedom Motion Errors

2020 ◽  
Vol 10 (15) ◽  
pp. 5057
Author(s):  
Chuang Sun ◽  
Sheng Cai ◽  
Yusheng Liu ◽  
Yanfeng Qiao
Keyword(s):  
Simultaneous Measurement ◽  
Measurement Accuracy ◽  
Measurement Data ◽  
Optical Path ◽  
Degree Of Freedom ◽  
Experimental Setup ◽  
Collimation System ◽  
Optical Configuration ◽  
Series Of Experiments ◽  
The Common

A compact laser collimation system is presented for the simultaneous measurement of five-degree-of-freedom motion errors. The optical configuration of the proposed system is designed, and the principle of the measurement of five-degree-of-freedom errors is described in detail. The resolution of the roll and the horizontal straightness is doubled compared with other laser collimation methods. A common optical path compensation method is provided to detect light drift in real time and compensate for straightness and angle errors. An experimental setup is constructed, and a series of experiments are performed to verify the feasibility and stability of the system. Compared with commercial instruments, the pitch and yaw residuals are ± 2.5 ″ and ± 3.5 ″ without correction, and the residuals are ± 1.9 ″ and ± 2.8 ″ after correction, respectively. The comparison deviations of the horizontal straightness and vertical straightness changed from ± 4.8   μ m to ± 2.8 μm and ± 5.9 μm to ± 3.6 μm, respectively. The comparison deviation of the roll is ± 4.3 ″ . The experimental results show that the data of the five-degree-of-freedom measurement system obtained are largely the same as the measurement data of commercial instruments. The common optical path compensation can effectively improve the measurement accuracy of the system.

scholarly journals Response of Common Bean Cultivars and Lines to Aluminum Toxicity

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 296
Author(s):  
José dos Santos Neto ◽  
Jessica Delfini ◽  
Tiago Willian Silva ◽  
Anderson Akihide Hirose ◽  
João Marcos Novais ◽  
...  
Keyword(s):  
Common Bean ◽  
Early Identification ◽  
Cell Expansion ◽  
Aluminum Toxicity ◽  
Al Toxicity ◽  
Yield Losses ◽  
Phaseolus Vulgaris L ◽  
Second Stage ◽  
Series Of Experiments ◽  
The Common

The soils in the common bean-producing regions (Phaseolus vulgaris L.) of Brazil are usually acid and conta\y66\yin toxic levels of aluminum (Al) for plants. This ion causes yield losses by inhibiting root cell expansion, thus reducing water and nutrient uptake. This study investigates the optimal Al concentration for the screening of genotypes in hydroponics cultivation and tries to identify cultivars and lines for cultivation in Al-toxic soils. The study consisted of two series of experiments. In the first one, four cultivars were evaluated at five Al concentrations (0, 2.5, 5, 7.5 and 10 ppm) and in the second, four independent tests were carried out (1-carioca, 2-black, 3-red, and 4-white), each with seven genotypes and two Al concentrations (0 and 4 ppm). The optimized concentration of Al in the first stage was 4 ppm, which allowed the early identification of genotypes with less affected development under Al toxicity in the second stage. The common bean cultivars IPR Quero-Quero (carioca group), BRS Esplendor (black group), KID 44 (red group), and WLine 5 (white group) may be indicated for cultivation under Al toxicity.

Perceptual Phenomena and Personality in Sensory Deprivation

1968 ◽  
Vol 114 (517) ◽  
pp. 1499-1508 ◽  
Author(s):  
J. P. Leff
Keyword(s):  
Sensory Deprivation ◽  
Prisoners Of War ◽  
Human Beings ◽  
Scientific Interest ◽  
Common Features ◽  
The People ◽  
The Social ◽  
Normal Human ◽  
Series Of Experiments ◽  
The Common

From time to time, normal human beings not suffering from any mental illness have reported experiences either akin to or identical with hallucinations (Byrd, 1938; Slocum, 1948; Ritter, 1954; Bombard, 1955). The common features in these reports have been the social isolation of the people involved and the physical hardships of their living conditions. They have usually been solitary mariners or polar explorers. Scientific interest was not aroused in these phenomena until directed to them by the experiences of prisoners of war in Korea who had undergone “brain-washing” techniques. At this time, Hebb and his colleagues began a series of experiments which opened up an era of widespread research into the field of Sensory Deprivation.

scholarly journals AN ENERGY-BASED APPROACH FOR DETECTION AND CHARACTERIZATION OF SUBTLE ENTITIES WITHIN LASER SCANNING POINT-CLOUDS

2016 ◽  
Vol XLI-B3 ◽  
pp. 167-171
Author(s):  
Reuma Arav ◽  
Sagi Filin
Keyword(s):  
Laser Scanning ◽  
Optimization Problem ◽  
Point Clouds ◽  
Urban Environments ◽  
Natural Environments ◽  
Detection Scheme ◽  
Airborne Laser ◽  
The Common ◽  
Geomorphological Features

Airborne laser scans present an optimal tool to describe geomorphological features in natural environments. However, a challenge arises in the detection of such phenomena, as they are embedded in the topography, tend to blend into their surroundings and leave only a subtle signature within the data. Most object-recognition studies address mainly urban environments and follow a general pipeline where the data are partitioned into segments with uniform properties. These approaches are restricted to man-made domain and are capable to handle limited features that answer a well-defined geometric form. As natural environments present a more complex set of features, the common interpretation of the data is still manual at large. In this paper, we propose a data-aware detection scheme, unbound to specific domains or shapes. We define the recognition question as an energy optimization problem, solved by variational means. Our approach, based on the level-set method, characterizes geometrically local surfaces within the data, and uses these characteristics as potential field for minimization. The main advantage here is that it allows topological changes of the evolving curves, such as merging and breaking. We demonstrate the proposed methodology on the detection of collapse sinkholes.

scholarly journals Active and Passive Haptic Perception of Shape: Passive Haptics Can Support Navigation

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 355 ◽  
Author(s):  
José-Luis Rodríguez ◽  
Ramiro Velázquez ◽  
Carolina Del-Valle-Soto ◽  
Sebastián Gutiérrez ◽  
Jorge Varona ◽  
...  
Keyword(s):  
Motor Activity ◽  
Haptic Perception ◽  
Shape Recognition ◽  
Haptic Interactions ◽  
Passive Haptics ◽  
First Case ◽  
Challenging Tasks ◽  
Series Of Experiments ◽  
Perceptual Characteristics ◽  
Haptic Environments

Real-time haptic interactions occur under two exploration modes: active and passive. In this paper, we present a series of experiments that evaluate the main perceptual characteristics of both exploration modes. In particular, we focus on haptic shape recognition as it represents a fundamental task in many applications using haptic environments. The results of four experiments conducted with a group of 10 voluntary subjects show that the differences in motor activity between active and passive haptics ease the perception of surfaces for the first case and the perception of pathways for the latter. In addition, the guidance nature of passive haptics makes the pathway direction easy to recognize. This work shows that this last observation could find application in more challenging tasks such as navigation in space.

Full paper: Shape recognition with point clouds in rebars

2012 ◽  
Vol 11 (2) ◽  
Author(s):  
K. Ishida ◽  
N. Kano ◽  
K. Kimoto
Keyword(s):  
Shape Recognition ◽  
Point Clouds ◽  
Full Paper

Shape recognition with point clouds in rebars

2012 ◽  
Vol 11 (2) ◽  
Author(s):  
K. Ishida ◽  
N. Kano ◽  
K. Kimoto
Keyword(s):  
Shape Recognition ◽  
Point Clouds

Sampling the Web as Training Data for Text Classification

2012 ◽  
pp. 293-310
Author(s):  
Wei-Yen Day ◽  
Chun-Yi Chi ◽  
Ruey-Cheng Chen ◽  
Pu-Jen Cheng
Keyword(s):  
Data Acquisition ◽  
Text Classification ◽  
Document Classification ◽  
The Other ◽  
Training Data ◽  
Class A ◽  
Classifier Performance ◽  
Series Of Experiments ◽  
The Common ◽  
The Web

Data acquisition is a major concern in text classification. The excessive human efforts required by conventional methods to build up quality training collection might not always be available to research workers. In this paper, the authors look into possibilities to automatically collect training data by sampling the Web with a set of given class names. The basic idea is to populate appropriate keywords and submit them as queries to search engines for acquiring training data. The first of two methods presented in this paper is based on sampling the common concepts among classes and the other is based on sampling the discriminative concepts for each class. A series of experiments were carried out independently on two different datasets and results show that the proposed methods significantly improve classifier performance even without using manually labeled training data. The authors’ strategy for retrieving Web samples substantially helps in the conventional document classification in terms of accuracy and efficiency.

Critical Properties of the Assembly Call of the Common American Crow

Behaviour ◽  
1978 ◽  
Vol 64 (3-4) ◽  
pp. 184-203 ◽  
Author(s):  
Nicholas S. Thompson ◽  
David B. Richards
Keyword(s):  
Sound Source ◽  
Traditional View ◽  
High Rate ◽  
American Crow ◽  
Corvus Brachyrhynchos ◽  
Temporal Properties ◽  
Series Of Experiments ◽  
The Common ◽  
Functional Context ◽  
Better Than

AbstractAccording to tradition, the communication system of the American crow, Corvus brachyrhynchos, consists of an assortment of distinct sounds each of which is used in a particular context and has a unique meaning. Despite this traditional view, we have made field observations which suggested that the sounds employed in various different functional contexts overlap considerably. These observations further suggested that each sound does not have a single unique meaning, but that its meaning varies depending upon how it and similar sounds are temporally organized into calling sequences. In order to investigate this idea, a series of experiments were performed in which the temporal properties of natural sounds recorded from crows in the field were changed. These experiments were concerned primarily with the vocalization known as the assembly call. The assembly call consists of series of sounds which are low, harsh, and variable in pitch and timing. Broadcast to crows in the field, recorded assembly calls provoke an aggregation of crows to the sound source about twenty-five percent of the time. The recordings broadcasted were of two sorts: sequences made up by modifying the temporal properties of a natural assembly call and sequences of sounds derived from calls given in other functional contexts which were then rearranged to approximate the temporal properties of an assembly call. These calls were tested on wild crows in the field. A presentation of a call was counted successful if at least one crow approached the sound source on a direct line. Different calls were compared with respect to the proportion of successful presentations. The results show that not all types of crow sounds can be manufactured into effective assembly calls. A high pitched call, even when arranged to approximate the temporal properties of the assembly call does not assemble crows at rates approaching the rate of assembly to natural assembly calls. On the other hand, the results also show that a sound need not be derived from an assembly call in order to be arranged into an effective assembly call. A call recorded in another functional context, but which has a harsh, grainy quality will assemble crows as well as or better than an assembly call if it is presented in the proper temporal arrangement. In fact, the highest rates of success were provoked by a sequence of such sounds having a high rate of emission and organized into short cycles of increasing rate. Such a call is two to four times more effective than a natural assembly call. These results are inconsistent with the traditional view that each particular caw in the repertoire of a crow has a discrete stable meaning. An alternate hypothesis is suggested in which the meaning of a sequence of crow sounds is thought to depend not only on the properties of the caws but upon the temporal properties of the sequence as well.

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