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On the optimality of grid cells [article]

Christos H. Papadimitriou
2016 arXiv   pre-print
Grid cells are widely believed to be involved in path integration, that is, the maintenance of a location state through the summation of small displacements.  ...  In two dimensions, under additional assumptions it can be shown that measurement sensitivity is optimized by the product of two sinusoids, again yielding a grid-like pattern.  ...  Acknowledgment: Many thanks to Reza Moazzezi for fruitful collaboration during the early stages of this work, to Umesh Vazirani for illuminating discussions, and to Christos-Alexandros Psomas for help  ... 
arXiv:1606.04876v1 fatcat:jkgfwzcbfbfsjp5qksqjxticva

A user centric self-optimizing grid-based approach for antenna steering based on call detail records

Naim Bitar, Ali Imran, Hazem Refai
2016 2016 IEEE Wireless Communications and Networking Conference  
To be able to maximize average user throughput on a cell level, we perform optimization of sector azimuth angles based on user centric weighted grids.  ...  In comparison to an optimal brute-force method that takes into account the location of every user to optimize the azimuth angles in a cell, we show that the proposed grid based self-optimization approach  ...  Optimization of azimuth angles in a cell are based on grid weights, thus different grid sizes, yield different weights and in turn affect the optimization of the azimuth angles.  ... 
doi:10.1109/wcnc.2016.7564931 dblp:conf/wcnc/BitarIR16 fatcat:ewhcn7nchbeofkgzyhv2mbpmwq

Vector Spatial Big Data Storage and Optimized Query Based on the Multi-Level Hilbert Grid Index in HBase

Hua Jiang, Junfeng Kang, Zhenhong Du, Feng Zhang, Xiangzhi Huang, Renyi Liu, Xuanting Zhang
2018 Information  
In the paper, we focus on the storage and topological query of vector polygon geometry data in HBase, and the rowkey in the HBase table is the concatenation of the Hilbert value of the grid cell to which  ...  Finally, based on the Q-HBML index, two query optimization strategies and an optimized topological query algorithm, ML-OTQ, are presented to optimize the topological query process and enhance the topological  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/info9050116 fatcat:5rb7npier5fnvanzvclg5grwl4

Fabrication of High Voltage Modules by Optimization of Performances of Reduced Area Silicon Solar Cells

David Bertrand, Marc Pirot, Sylvain Manuel, Anne Kaminski Cachopo, Yannick Veschetti
2016 Energy Procedia  
The optimization of the front metallization grid allows the fabrication of small area cells with similar efficiency as 6 inches cells.  ...  First, we investigated the influence of the cell dimension on the efficiency.  ...  Based on the cell front grid optimization, table 1 shows the performance of the mini-modules with 12 cleaved cells and with one reference 6 inches cell.  ... 
doi:10.1016/j.egypro.2016.07.049 fatcat:3chz2xqqlrbfnhlzq6yxv5hfmq

Determination of discrete sampling grids with optimal topological and spectral properties [chapter]

Luis Ibáñez, Chafiaâ Hamitouche, Christian Roux
1996 Lecture Notes in Computer Science  
It is shown here that those grids have advantages with respect to the classically used 23 n grid. The proposed 3D grids are used to achieve surface extraction from volume data.  ...  This paper proposes 2D, 3D and 4D discrete sampling grids with optimal topological and spectra] properties.  ...  The ratio between the two grids is x/~/4, what means that the optimal grid has the 55.90% of samples of the Z 4 grid.  ... 
doi:10.1007/3-540-62005-2_15 fatcat:dfpft7up2rfwzbxplcvvuz5vtm

Optimization of three-dimensional computational grids

1986 Journal of Aircraft  
Qualitatively, the desirable properties of the master cell are stated as: 1) Smoothness: The master cell is smooth if the change in cell volume from one of its grid cells to the next is minimal, in all  ...  The grid is essentially optimized after 20 iterations. In spite of a nearly constant smoothness, after 30 iterations one singular master cell appears at the nose tip.  ... 
doi:10.2514/3.45323 fatcat:t63eaohjhnb4bjmh7aanfiz3te

Duality and Dimensionality Reduction Discrete Line Generation Algorithm for a Triangular Grid

Lingyu Du, Qiuhe Ma, Jin Ben, Rui Wang, Jiahao Li
2018 ISPRS International Journal of Geo-Information  
Third, the two-dimensional discrete line model is solved by transforming it into a one-dimensional optimal wandering path model.  ...  In this study, we propose a method for constructing a discrete line mathematical model for a triangular grid based on a "weak duality" hexagonal grid, to overcome the drawbacks of existing discrete line  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/ijgi7100391 fatcat:pswopfjphbhjbmjttvbjpsigjm

Layout Generator with Flexible Grid Assignment for Area Efficient Standard Cell

Shinichi Nishizawa, Tohru Ishihara, Hidetoshi Onodera
2015 IPSJ Transactions on System LSI Design Methodology  
The generator reduces the cost of library design and enables an optimization of each cell with detailed layout information that can be used to estimate the performance of the cell under design.  ...  It can generate an area efficient layout from a virtual-grid symbolic layout with the ability of flexible grid positioning that considers local design rules enforced in a scaled technology.  ...  Since the available number of horizontal wire track on the mask layout depend on the PMOS and NMOS width and it is affected by mask design rule and target cell height, GridY of virtual grid is not able  ... 
doi:10.2197/ipsjtsldm.8.131 fatcat:2h2n2pm3sfehzi733excdvt46i

Optimized Icosahedral Grids: Performance of Finite-Difference Operators and Multigrid Solver

Ross P. Heikes, David A. Randall, Celal S. Konor
2013 Monthly Weather Review  
This paper discusses the generation of icosahedral hexagonal-pentagonal grids, optimization of the grids, how optimization affects the accuracy of finite-difference Laplacian, Jacobian, and divergence  ...  Three different grid optimization methods are compared through an error convergence analysis. The optimization process increases the accuracy of the operators.  ...  The grid distances on the optimized grid are slightly less uniform than those on the unoptimized IHP grid.  ... 
doi:10.1175/mwr-d-12-00236.1 fatcat:6em3bljfindoxlrsdbwicyo2tu

Isotropic Grids Revisited: A Numerical Study of Solar Cell Electrode Geometries

Oliver Nakano-Baker, Clay Boyd, Caitlin Cramer, Lucien Brush, J. Devin MacKenzie
2022 IEEE Transactions on Electron Devices  
We present a simple numerical framework for modeling the shadow and resistive losses in circular H-bar and isotropic grids and for optimizing the pitch and width of the designs.  ...  losses in the cell material and metal lines.  ...  Convex optimization of the numerical expressions was used to rapidly identify near-optimal configurations of H-bar and isotropic grids on circular solar cells with a single central current sink.  ... 
doi:10.1109/ted.2022.3174810 fatcat:5pxxvun6t5dvxf5hjb4b7zo6gm

Aerodynamic Shape Optimization using Discrete Adjoint Formulation based on Overset Mesh System

Byung-Joon Lee, Jin-Woo Yim, Jun-Sok Yi, Chong-Am Kim
2007 International Journal of Aeronautical and Space Sciences  
A smooth geometric modification on the overlapped surface boundaries and evaluation of analytic grid sensitivities can be performed by Spline patch and mapping from physical grids to the patched Spline  ...  Moreover, a new postprocessing method, Spline-Boundary Intersecting Grid (S-BIG) scheme, is proposed by considering the ratio of cell area for more refined prediction of aerodynamic coefficients and convenient  ...  Assuming that Zipper grid scheme is reconstruction of grids on the level of a block, S-BIG is reconstitution of grids on the level of a cell.  ... 
doi:10.5139/ijass.2007.8.1.095 fatcat:g6g6qtaesnevfagykq4qqo3roy

From 1 Sun to 10 Suns c-Si Cells by Optimizing Metal Grid, Metal Resistance, and Junction Depth

Vikrant A. Chaudhari, Chetan S. Solanki
2009 International Journal of Photoenergy  
Step by step optimization of commercial cell in terms of grid geometry, junction depth, and electroplating of the front metal contacts is proposed.  ...  The optimized cell with grid optimization, junction optimization, electroplating, and junction optimized with electroplated contacts cell gives resistive power loss of 20%, 16%, 11%, and 8%, respectively  ...  Case-3: Electroplated Front Grid Contacts on Solar Cells Front metal grid (fingers and bus-bars) and back Al metal contacts on solar cells are usually fabricated using screen printing of the metal paste  ... 
doi:10.1155/2009/827402 fatcat:vy7iwtqj45hsxl5egnhixtpy3i

Efficient methods for finding influential locations with adaptive grids

Da Yan, Raymond Chi-Wing Wong, Wilfred Ng
2011 Proceedings of the 20th ACM international conference on Information and knowledge management - CIKM '11  
work and the number of clients attracted by a new server in the result location often exceeds 98% of the optimal.  ...  Using our relaxed model, we design an efficient grid-based approximation algorithm called FILM (Fast Influential Location Miner) to the queries, which is orders of magnitude faster than the bestknown previous  ...  FILM returns a grid cell in which each location is an influential one, as an approximation of the optimal location.  ... 
doi:10.1145/2063576.2063788 dblp:conf/cikm/YanWN11 fatcat:7dvr54f6ufhmndzqvvytb62ocy

Optimal multidimensional quantization for pattern recognition

Mingzhou Song, Robert M. Haralick, Wei Sui
2002 Second International Conference on Image and Graphics  
We illustrate the effectiveness of optimal quantization on a set of not very well separated Gaussian mixture models, as compared to the expectation maximization (EM) algorithm.  ...  In non-parametric pattern recognition, the probability density function is approximated by means of many parameters, each one for a density value in a small hyper-rectangular volume of the space.  ...  decision boundary of a grid is moved, we need only recalculate the change of the additive measures on those affected cells and data.  ... 
doi:10.1117/12.477142 fatcat:v6kyv5t6tzak7pt35oj3ljc4ly

Page 420 of Journal of Aircraft Vol. 23, Issue 5 [page]

1986 Journal of Aircraft  
The grid is essentially optimized after 20 iterations. In spite of a nearly constant smoothness, after 30 iterations one singular master cell appears at the nose tip.  ...  Obviously, optimizing the grid in terms of smoothness only (a = 0) allows a much faster untangling of the initial singular grid.  ... 
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