A Fast and Efficient Compact Packing Algorithm for Free-Form Objects

2008 ◽  
Author(s):  
Santosh Tiwari ◽  
Georges Fadel ◽  
Peter Fenyes
Keyword(s):  
Three Dimensional ◽  
Superior Performance ◽  
Free Form ◽  
Layout Algorithm ◽  
Packing Algorithm ◽  
Packing Efficiency

In this paper, a compact packing algorithm for the placement of objects inside a container is described. The proposed packing algorithm packs three-dimensional free-form objects inside an arbitrary enclosure such that the packing efficiency is maximized. The proposed packing algorithm can handle objects with holes or cavities and its performance does not degrade significantly with the increase in complexity of the enclosure or the objects. The packing algorithm takes as input the triangulated geometry of the container and all the objects to be packed and outputs the list of objects that can be placed inside the enclosure. The packing algorithm also outputs the location and orientation of all the objects, the packing sequence, and the packed configuration. An improved layout algorithm that works with arbitrary container geometry is also proposed. Several heuristics to improve the performance of the packing algorithm as well as certain aspects that facilitate fast and efficient handling of CAD data are also discussed. A comprehensive benchmarking of the proposed packing algorithm on synthetic and hypothetical problems reflects its superior performance as compared to other similar approaches.

A Fast and Efficient Compact Packing Algorithm for SAE and ISO Luggage Packing Problems

2010 ◽  
Vol 10 (2) ◽  
Author(s):  
Santosh Tiwari ◽  
Georges Fadel ◽  
Peter Fenyes
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Superior Performance ◽  
Free Form ◽  
Layout Algorithm ◽  
Packing Problems ◽  
Packing Algorithm ◽  
Computer Aided ◽  
Packing Efficiency ◽  
Aided Design

In this paper, a compact packing algorithm for the placement of objects inside a container is described. The proposed packing algorithm is designed to pack three-dimensional free-form objects inside an arbitrary enclosure such that the packing efficiency is maximized. The proposed packing algorithm can handle objects with holes or cavities, and its performance does not degrade significantly with the increase in complexity of the enclosure or the objects. The packing algorithm takes as input the tessellated geometry of the container and all the objects to be packed and outputs the list of objects that can be placed inside the enclosure. The packing algorithm also outputs the location and orientation of all the objects, the packing sequence, and the packed configuration. An improved layout algorithm that works with arbitrary container geometry is also proposed. Separate layout algorithms for the SAE and ISO luggage are developed. Several heuristics to improve the performance of the packing algorithm are also incorporated. Certain aspects that facilitate fast and efficient handling of the computer aided design (CAD) data are also discussed. A comprehensive benchmarking of the proposed packing algorithm on synthetic and hypothetical problems reflects its superior performance as compared with other similar approaches.

scholarly journals A Novel LOS Decision Technique Reflecting 3D DTED for Modeling an Electronic Warfare Environment

2021 ◽  
Vol 11 (1) ◽  
pp. 409
Author(s):  
Jaejoong Lee ◽  
Chiho Lee ◽  
Hyeon Hwi Lee ◽  
Kyung Tae Park ◽  
Hyun-Kyo Jung ◽  
...  
Keyword(s):  
Interpolation Method ◽  
Three Dimensional ◽  
Superior Performance ◽  
Line Of Sight ◽  
Electronic Warfare ◽  
Decision Algorithm ◽  
Elevation Data ◽  
The Republic ◽  
Point Distance ◽  
Terrain Elevation

A new line-of-sight (LOS) decision algorithm applicable to simulation of electronic warfare (EW) is developed. For accurate simulation, the digital terrain elevation data (DTED) of the region to be analyzed must be reflected in the simulation, and millions of datasets are necessary in the EW environment. In order to obtain real-time results in such an environment, a technology that determines line-of-sight (LOS) quickly and accurately is very important. In this paper, a novel algorithm is introduced for determining LOS that can be applied in an EW environment with three-dimensional (3D) DTED. The proposed method shows superior performance as compared with the simplest point-to-point distance calculation method and it is also 50% faster than the conventional interpolation method. The DTED used in this paper is the data applied as level 0 for the Republic of Korea, and the decision of the LOS at approximately 1.8 million locations viewed by a reconnaissance plane flying 10 km above the ground is determined within 0.026 s.

scholarly journals Two view NURBS reconstruction based on GACO model

2021 ◽  
Author(s):  
Deepika Saini ◽  
Sanoj Kumar ◽  
Manoj K. Singh ◽  
Musrrat Ali
Keyword(s):  
Optimization Algorithms ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Least Square ◽  
Ant Colony ◽  
Free Form ◽  
Reconstruction Process ◽  
Nurbs Curve ◽  
Data Points ◽  
Ant Colony Optimization Algorithms

AbstractThe key job here in the presented work is to investigate the performance of Generalized Ant Colony Optimizer (GACO) model in order to evolve the shape of three dimensional free-form Non Uniform Rational B-Spline (NURBS) curve using stereo (two) views. GACO model is a blend of two well known meta-heuristic optimization algorithms known as Simple Ant Colony and Global Ant Colony Optimization algorithms. Basically, the work talks about the solution of NURBS-fitting based reconstruction process. Therefore, GACO model is used to optimize the NURBS parameters (control points and weights) by minimizing the weighted least-square errors between the data points and the fitted NURBS curve. The algorithm is applied by first assuming some pre-fixed values of NURBS parameters. The experiments clearly show that the optimization procedure is a better option in a case where good initial locations of parameters are selected. A detailed experimental analysis is given in support of our algorithm. The implemented error analysis shows that the proposed methodology perform better as compared to the conventional methods.

scholarly journals Deciphering the Role of Residues Involved in Disorder-To-Order Transition Regions in Archaeal tRNA Methyltransferase 5

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 399
Author(s):  
Ambuj Srivastava ◽  
Dhanusha Yesudhas ◽  
Shandar Ahmad ◽  
M. Michael Gromiha
Keyword(s):  
Three Dimensional ◽  
Md Simulations ◽  
Order Transition ◽  
Free Form ◽  
Wild Type ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Type Complex ◽  
In The Wild ◽  
Trna Methyltransferase

tRNA methyltransferase 5 (Trm5) enzyme is an S-adenosyl methionine (AdoMet)-dependent methyltransferase which methylates the G37 nucleotide at the N1 atom of the tRNA. The free form of Trm5 enzyme has three intrinsically disordered regions, which are highly flexible and lack stable three-dimensional structures. These regions gain ordered structures upon the complex formation with tRNA, also called disorder-to-order transition (DOT) regions. In this study, we performed molecular dynamics (MD) simulations of archaeal Trm5 in free and complex forms and observed that the DOT residues are highly flexible in free proteins and become stable in complex structures. The energetic contributions show that DOT residues are important for stabilising the complex. The DOT1 and DOT2 are mainly observed to be important for stabilising the complex, while DOT3 is present near the active site to coordinate the interactions between methyl-donating ligands and G37 nucleotides. In addition, mutational studies on the Trm5 complex showed that the wild type is more stable than the G37A tRNA mutant complex. The loss of productive interactions upon G37A mutation drives the AdoMet ligand away from the 37th nucleotide, and Arg145 in DOT3 plays a crucial role in stabilising the ligand, as well as the G37 nucleotide, in the wild-type complex. Further, the overall energetic contribution calculated using MMPBSA corroborates that the wild-type complex has a better affinity between Trm5 and tRNA. Overall, our study reveals that targeting DOT regions for binding could improve the inhibition of Trm5.

An Equivalent-Plane Cross-Coupling Position Control for Contour-Accuracy Improvement in Three-Axis Free-Form Contour Following Tasks

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Jian-Wei Ma ◽  
De-Ning Song ◽  
Zhen-Yuan Jia ◽  
Wen-Wen Jiang ◽  
Fu-Ji Wang ◽  
...  
Keyword(s):  
Error Control ◽  
Position Control ◽  
Three Dimensional ◽  
Cross Coupling ◽  
Experimental Tests ◽  
Numerical Control ◽  
Free Form ◽  
Contouring Error ◽  
Contour Following ◽  
Better Than

To reduce the contouring errors in computer-numerical-control (CNC) contour-following tasks, the cross-coupling controller (CCC) is widely researched and used. However, most existing CCCs are well-designed for two-axis contouring and can hardly be generalized to compensate three-axis curved contour following errors. This paper proposes an equivalent-plane CCC scheme so that most of the two-axis CCCs or flexibly designed algorithms can be utilized for equal control of the three-axis contouring errors. An initial-value regeneration-based Newton method is first proposed to compute the foot point from the actual motion position to the desired contour with a high accuracy, so as to establish the equivalent plane where the estimated three-dimensional contouring-error vector is included. After that, the signed contouring error is computed in the equivalent plane, thus a typical two-axis proportional-integral-differential (PID)-based CCC is utilized for its control. Finally, the two-axis control commands generated by the typical CCC are coupled to three-axis control commands according to the geometry of the established equivalent plane. Experimental tests are conducted to verify the effectiveness of the presented method. The testing results illustrate that the proposed equivalent-plane CCC performs much better than conventional method in both error estimation and error control.

Kinesthetically Augmented Mid-Air Sketching of Multi-Planar 3D Curve-Soups

2018 ◽  
Author(s):  
Ronak R. Mohanty ◽  
Umema H. Bohari ◽  
Vinayak ◽  
Eric Ragan
Keyword(s):  
Force Feedback ◽  
Three Dimensional ◽  
Free Form ◽  
Manual Labor ◽  
3D Design ◽  
Planar Curves ◽  
Kinesthetic Feedback ◽  
Curve Modeling

We present haptics-enabled mid-air interactions for sketching collections of three-dimensional planar curves — 3D curve-soups — as a means for 3D design conceptualization. Haptics-based mid-air interactions have been extensively studied for modeling of surfaces and solids. The same is not true for modeling curves; there is little work that explores spatiality, tangibility, and kinesthetics for curve modeling, as seen from the perspective of 3D sketching for conceptualization. We study pen-based mid air interactions for free-form curve input from the perspective of manual labor, controllability, and kinesthetic feedback. For this, we implemented a simple haptics-enabled workflow for users to draw and compose collections of planar curves on a force-enabled virtual canvas. We introduce a novel force-feedback metaphor for curve drawing, and investigate three novel rotation techniques within our workflow for both controlled and free-form sketching tasks.

scholarly journals Use of Magnetic Field for Mitigating Gyroscope Errors for Indoor Pedestrian Positioning

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2592 ◽  
Author(s):  
Ming Ma ◽  
Qian Song ◽  
Yang Gu ◽  
Zhimin Zhou
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Inertial Navigation System ◽  
Three Dimensional ◽  
Calibration Method ◽  
Rate Of Change ◽  
Superior Performance ◽  
Novel Approach ◽  
Straight Line ◽  
Magnetometer Calibration

In the field of indoor pedestrian positioning, the improved Quasi-Static magnetic Field (iQSF) method has been proposed to estimate gyroscope biases in magnetically perturbed environments. However, this method is only effective when a person walks along straight-line paths. For other curved or more complex path patterns, the iQSF method would fail to detect the quasi-static magnetic field. To address this issue, a novel approach is developed for quasi-static magnetic field detection in foot-mounted Inertial Navigation System. The proposed method detects the quasi-static magnetic field using the rate of change in differences between the magnetically derived heading and the heading derived from gyroscope. In addition, to eliminate the distortions caused by system platforms and shoes, a magnetometer calibration method is developed and the calibration is transformed from three-dimensional to two-dimensional coordinate according to the motion model of a pedestrian. The experimental results demonstrate that the proposed method can provide superior performance in suppressing the heading errors with the comparison to iQSF method.

scholarly journals Microribbons composed of directionally self-assembled nanoflakes as highly stretchable ionic neural electrodes

2020 ◽  
Vol 117 (26) ◽  
pp. 14667-14675 ◽  
Author(s):  
Mingchao Zhang ◽  
Rui Guo ◽  
Ke Chen ◽  
Yiliang Wang ◽  
Jiali Niu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Structural Variation ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Superior Performance ◽  
Ionic Conductors ◽  
Structural Variations ◽  
Neural Electrodes ◽  
Self Assembled

Many natural materials possess built-in structural variation, endowing them with superior performance. However, it is challenging to realize programmable structural variation in self-assembled synthetic materials since self-assembly processes usually generate uniform and ordered structures. Here, we report the formation of asymmetric microribbons composed of directionally self-assembled two-dimensional nanoflakes in a polymeric matrix during three-dimensional direct-ink printing. The printed ribbons with embedded structural variations show site-specific variance in their mechanical properties. Remarkably, the ribbons can spontaneously transform into ultrastretchable springs with controllable helical architecture upon stimulation. Such springs also exhibit superior nanoscale transport behavior as nanofluidic ionic conductors under even ultralarge tensile strains (>1,000%). Furthermore, to show possible real-world uses of such materials, we demonstrate in vivo neural recording and stimulation using such springs in a bullfrog animal model. Thus, such springs can be used as neural electrodes compatible with soft and dynamic biological tissues.

scholarly journals Bechmann’s Number for Harmonic Overtones of Thickness-Shear Vibrations of Rotated Y-Cut Quartz Crystal Plates

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 667
Author(s):  
Han Zhang ◽  
Yumei Chen ◽  
Ji Wang
Keyword(s):  
Experimental Data ◽  
Wave Propagation ◽  
Quartz Crystal ◽  
Three Dimensional ◽  
Approximate Solutions ◽  
Superior Performance ◽  
Shear Modes ◽  
Practical Experiences ◽  
Quartz Crystal Resonators ◽  
Thickness Shear

A procedure based on approximate solutions of three-dimensional equations of wave propagation is utilized for calculating Bechmann’s number for the harmonic overtones of thickness-shear modes in the rotated Y-cut quartz crystal plates. Bechmann’s number is used for the optimization and improvement of electrodes to yield superior performance in the design of quartz crystal resonators. Originally, Bechmann’s number is found through practical experiences, and analytical results were provided afterward to enable optimal design of novel resonator structures. The outcomes in this study are from a simplified theoretical prediction and they are consistent with known empirical results, making it is possible to design optimal quartz crystal resonators for cases without adequate experimental data for a higher frequency and smaller size.

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