Results 81 to 90 of about 4,255,094 (265)

Points, cells, or polygons? On the choice of spatial units in forest conservation policy impact evaluation

Environmental Research Letters
A fast-growing literature uses remotely sensed land-cover data along with quasi-experimental statistical methods to assess the efficacy of forest conservation interventions.
Allen Blackman, Emilio Leguízamo, Laura Villalobos   +2 more
doaj   +1 more source

Review and prospect of coal mine informatization constructio

Gong-kuang zidonghua, 2020
Based on the definition of coal mine informatization, the characteristics, typical problems and their representative solutions in different stages of coal mine informatization construction are reviewed, which include single machine(system) automation ...
DING Enjie, LIAO Yubo, ZHANG Lei, LIU Zhongyu   +3 more
doaj   +1 more source

A simple model of trees for unicellular maps [PDF]

Discrete Mathematics & Theoretical Computer Science, 2012
We consider unicellular maps, or polygon gluings, of fixed genus. In FPSAC '09 the first author gave a recursive bijection transforming unicellular maps into trees, explaining the presence of Catalan numbers in counting formulas for these objects.
Guillaume Chapuy, Valentin Feray, Eric Fusy   +2 more
doaj   +1 more source

Packing identical simple polygons is NP-hard

, 2012
Given a small polygon S, a big simple polygon B and a positive integer k, it is shown to be NP-hard to determine whether k copies of the small polygon (allowing translation and rotation) can be placed in the big polygon without overlap.
Allen, Sarah R., Iacono, John
core  

Constant-work-space algorithms for geometric problems

Journal of Computational Geometry, 2011
Constant-work-space algorithms may use only constantly many cells of storage in addition to their input, which is provided as a read-only array.
Tetsuo Asano, Wolfgang Mulzer, Günter Rote, Yajun Wang   +3 more
doaj   +1 more source

Investigation on Classification and Cleaning for Visually Self-Intersected Monocyclic Polygons

IEEE Access, 2020
In the geographic information system field, identifying and cleaning self-intersected polygons to achieve simple polygons is a basic and core issue.
Chengming Li, Man Guo, Pengda Wu, Yong Yin   +3 more
doaj   +1 more source

A Fast Algorithm for Covering Rectangular Orthogonal Polygons with a Minimum Number of r-Stars

پژوهش‌های ریاضی, 2018
Introduction This paper presents an algorithm for covering orthogonal polygons with minimal number of guards. This idea examines the minimum number of guards for orthogonal simple polygons (without holes) for all scenarios and can also find a rectangular
Keivan Borna
doaj  

Recognizing Visibility Graphs of Polygons with Holes and Internal-External Visibility Graphs of Polygons

, 2018
Visibility graph of a polygon corresponds to its internal diagonals and boundary edges. For each vertex on the boundary of the polygon, we have a vertex in this graph and if two vertices of the polygon see each other there is an edge between their ...
Boomari, Hossein, Ostovari, Mojtaba, Zarei, Alireza   +2 more
core  

THE IMPORTANCE AND THE ROLE OF THE POLYGON IN THE DEVELOPMENT OF BIOMOTORING EXPERIENCES OF THE FIRST SERIES OF NINE YEARS LASTED ELEMENTARY SCHOOL STUDENTS [PDF]

Sport Mont, 2006
In order to underline the importance of the polygon for the students of the first series of nine years lasted school in the function of development, escort and control of the elementary monitoring experiences, in the sense of space solution, simple ...
Drago Milošević
doaj  

A Multi-Scale Hybrid Scene Geometric Similarity Measurement Method Using Heterogeneous Graph Neural Network

ISPRS International Journal of Geo-Information
Geographic features in maps consist of a mixture of points, polylines, and polygons, generally including POIs, roads, buildings, and other geographic features.
Chongya Gong, Tinghua Ai, Shiyu Chen, Tianyuan Xiao, Huafei Yu   +4 more
doaj   +1 more source