scholarly journals Common Edges in Rooted Trees and Polygonal Triangulations

10.37236/2541 ◽  
2013 ◽  
Vol 20 (1) ◽  
Author(s):  
Sean Cleary ◽  
Andrew Rechnitzer ◽  
Thomas Wong
Keyword(s):  
Polynomial Time ◽  
Rooted Trees ◽  
Binary Trees ◽  
Regular Polygons ◽  
Large Component ◽  
Polynomial Time Algorithms ◽  
The Common ◽  
Flip Distance ◽  
Degree Of Similarity ◽  
Insight Into

Rotation distance between rooted binary trees measures the degree of similarity of two trees with ordered leaves and is equivalent to edge-flip distance between triangular subdivisions of regular polygons. There are no known polynomial-time algorithms for computing rotation distance. Existence of common edges makes computing rotation distance more manageable by breaking the problem into smaller subproblems. Here we describe the distribution of common edges between randomly-selected triangulations and measure the sizes of the remaining pieces into which the common edges separate the polygons. We find that asymptotically there is a large component remaining after sectioning off numerous small polygons which gives some insight into the distribution of such distances and the difficulty of such distance computations, and we analyze the distributions of the sizes of the largest and smaller resulting polygons.

What Can Economists Contribute to the Common Good Tradition?

2017 ◽  
Author(s):  
Andrew M. Yuengert
Keyword(s):  
Common Good ◽  
Common Pool Resources ◽  
Economic Approach ◽  
Public And Private ◽  
Private Provision ◽  
The Public ◽  
The Common Good ◽  
The Common ◽  
The Individual ◽  
Insight Into

Although most economists are skeptical of or puzzled by the Catholic concept of the common good, a rejection of the economic approach as inimical to the common good would be hasty and counterproductive. Economic analysis can enrich the common good tradition in four ways. First, economics embodies a deep respect for economic agency and for the effects of policy and institutions on individual agents. Second, economics offers a rich literature on the nature of unplanned order and how it might be shaped by policy. Third, economics offers insight into the public and private provision of various kinds of goods (private, public, common pool resources). Fourth, recent work on the development and logic of institutions and norms emphasizes sustainability rooted in the good of the individual.

scholarly journals Reducing the metabolic energy of walking and running using an unpowered hip exoskeleton

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tiancheng Zhou ◽  
Caihua Xiong ◽  
Juanjuan Zhang ◽  
Di Hu ◽  
Wenbin Chen ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Design Method ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Spring Stiffness ◽  
Spatiotemporal Parameters ◽  
The Common ◽  
Hip Flexion ◽  
Optimal Stiffness ◽  
Insight Into

Abstract Background Walking and running are the most common means of locomotion in human daily life. People have made advances in developing separate exoskeletons to reduce the metabolic rate of walking or running. However, the combined requirements of overcoming the fundamental biomechanical differences between the two gaits and minimizing the metabolic penalty of the exoskeleton mass make it challenging to develop an exoskeleton that can reduce the metabolic energy during both gaits. Here we show that the metabolic energy of both walking and running can be reduced by regulating the metabolic energy of hip flexion during the common energy consumption period of the two gaits using an unpowered hip exoskeleton. Methods We analyzed the metabolic rates, muscle activities and spatiotemporal parameters of 9 healthy subjects (mean ± s.t.d; 24.9 ± 3.7 years, 66.9 ± 8.7 kg, 1.76 ± 0.05 m) walking on a treadmill at a speed of 1.5 m s−1 and running at a speed of 2.5 m s−1 with different spring stiffnesses. After obtaining the optimal spring stiffness, we recruited the participants to walk and run with the assistance from a spring with optimal stiffness at different speeds to demonstrate the generality of the proposed approach. Results We found that the common optimal exoskeleton spring stiffness for walking and running was 83 Nm Rad−1, corresponding to 7.2% ± 1.2% (mean ± s.e.m, paired t-test p < 0.01) and 6.8% ± 1.0% (p < 0.01) metabolic reductions compared to walking and running without exoskeleton. The metabolic energy within the tested speed range can be reduced with the assistance except for low-speed walking (1.0 m s−1). Participants showed different changes in muscle activities with the assistance of the proposed exoskeleton. Conclusions This paper first demonstrates that the metabolic cost of walking and running can be reduced using an unpowered hip exoskeleton to regulate the metabolic energy of hip flexion. The design method based on analyzing the common energy consumption characteristics between gaits may inspire future exoskeletons that assist multiple gaits. The results of different changes in muscle activities provide new insight into human response to the same assistive principle for different gaits (walking and running).

Studies on the Toxicity of Aromatic Hydrocarbons on Chorella Vulgaris by 3D-QSAR Using CoMFA and CoMSIA Methods

2012 ◽  
Vol 610-613 ◽  
pp. 3574-3579
Author(s):  
Cui Hua Wang ◽  
Sheng Long Yang ◽  
Chao Lu ◽  
Hong Xia Yu ◽  
Lian Shen Wang ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Aromatic Hydrocarbons ◽  
Common Factor ◽  
3D Qsar ◽  
The Other ◽  
Contour Maps ◽  
Substituent Group ◽  
Donor And Acceptor ◽  
The Common ◽  
Insight Into

By using CoMFA and CoMSIA methods, the new quantitative structures of 25 aromatic hydrocarbons and the 96 hr-EC50 data with C. vulgaris have been investigated to obtain more detailed insight into the relationships between molecular structure and bioactivity. Compared to CoMFA (the average Q2LOO option =0.610), CoMSIA (the average Q2LOO =0.736) has the better results with robustness and stability. CoMSIA analysis using steric, electrostatic, hydrophobic, and H-bond donor and acceptor descriptors show H-bond donor is the common factor for influencing the toxicity, the steric and electrostatic descriptors are next and the hydrophobic descriptor was last. From the contour maps, the number of benzene ring is more crucial for the compound toxicity and the compounds with more benzene ring make toxicity increased. Under the same number of benzene ring, the kind of substituent group and the formed ability of H-bond are the other parameters to influencing the aromatic hydrocarbons toxicity.

scholarly journals The development of a CEFR-based scale for assessing young foreign language learners’ writing skills

Linguistica ◽  
2014 ◽  
Vol 54 (1) ◽  
pp. 241-259
Author(s):  
Karmen Pižorn
Keyword(s):  
Foreign Language ◽  
Language Learners ◽  
Classroom Assessment ◽  
Writing Skills ◽  
Age Group ◽  
Young Learners ◽  
Foreign Language Learners ◽  
The Common ◽  
Literacy Research ◽  
Insight Into

The Common European Framework of Reference (CEFR) was designed with adults in mind, which is clearly reflected in the six levels encompassing a range of proficiency that represents lifelong learning. Therefore, any use of the CEFR levels as a basis for describing the ability of young learners requires adapting the content of each level, as well as identifying which levels on the scale are appropriate for children.The present article examines the contribution that feedback, in the form of an assessment scale, can make to valid classroom assessment of the writing of young learners, in the age group of 9–13 years. It shows that a scale of descriptors adapted from the CEFR can play a central role in this assessment. The article presents the AYLLIT (Assessment of Young Learner Literacy) research project, which developed a CEFR-based writing scale and guidelines for teachers, enabling them to provide their students with feedback, and to gain a clearer insight into their students’ progress. After describing the procedures followed in the project, the article examines the extent to which its outcomes may enable teachers to give feedback that could contribute to valid classroom assessment.

scholarly journals An Overview of Algorithms for Network Survivability

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
F. A. Kuipers
Keyword(s):  
Polynomial Time ◽  
Network Connectivity ◽  
Network Survivability ◽  
Disjoint Paths ◽  
Polynomial Time Algorithms ◽  
Concise Overview ◽  
Main Components

Network survivability—the ability to maintain operation when one or a few network components fail—is indispensable for present-day networks. In this paper, we characterize three main components in establishing network survivability for an existing network, namely, (1) determining network connectivity, (2) augmenting the network, and (3) finding disjoint paths. We present a concise overview of network survivability algorithms, where we focus on presenting a few polynomial-time algorithms that could be implemented by practitioners and give references to more involved algorithms.

scholarly journals Visual Comparison of Phylogenetic Trees Through iPhyloC, a New Interactive Web-based Framework

2021 ◽  
Author(s):  
Muhsen Hammoud ◽  
Charles Morphy Santos ◽  
Joao Paulo Gois
Keyword(s):  
Phylogenetic Trees ◽  
Binary Trees ◽  
Automatic Identification ◽  
Structural Comparison ◽  
Web Based ◽  
Visual Comparison ◽  
Large Trees ◽  
Cross Platform ◽  
The Common ◽  
Intuitive Design

Current side-by-side phylogenetic trees comparison frameworks face two issues: (1) accepting binary trees as input, and (2) assuming input trees having identical or highly overlapping taxa. We present a task abstraction of the problem of side-by-side comparison of two phylogenetic trees and propose a set-based measure for detailed structural comparison between two phylogenetic trees, which can be non-binary and not highly overlapping. iPhyloC is an interactive web-based framework including automatic identification of the common taxa in both trees, comparing input trees in several modes, intuitive design, high usability, scalability to large trees, and cross-platform support. iPhyloC was tested in hypothetical and real biological examples.

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