scholarly journals Probabilities of tree topologies with temporal constraints and diversification shifts

2021 ◽  
Vol 1 ◽  
Author(s):  
Gilles Didier
Keyword(s):  
Temporal Constraints ◽  
Tree Topologies

scholarly journals Probabilities of tree topologies with temporal constraints and diversification shifts

2018 ◽  
Author(s):  
Gilles Didier
Keyword(s):  
Time Complexity ◽  
Phylogenetic Trees ◽  
Exact Distribution ◽  
Tree Topology ◽  
Divergence Times ◽  
Computation Method ◽  
List Type ◽  
Temporal Constraints ◽  
Time Intervals ◽  
Tree Topologies

AbstractDating the tree of life is a task far more complicated that only determining the evolutionary relationships between species. It is therefore of interest to develop approaches able to deal with undated phylogenetic trees.The main result of this work is a method to compute probabilities of undated phylogenetic trees under piecewiseconstant-birth-death-sampling models by constraining some of the divergence times to belong to given time intervals and by allowing diversification shifts on certain clades. The computation is quite fast since its time complexity is quadratic with the size of the tree topology and linear with the number of time constraints and of “pieces” in the model.The interest of this computation method is illustrated with three applications, namely,to compute the exact distribution of the divergence times of a tree topology with temporal constraints,to directly sample the divergence times of a tree topology, andto test for a diversification shift at a given clade.

A CSP-Based Approach for Temporal Constraints in Temporal Planning

2012 ◽  
Vol 35 (8) ◽  
pp. 1759
Author(s):  
Li-Hua WU ◽  
Ai-Xiang CHEN ◽  
Yun-Fei JIANG ◽  
Rui BIAN
Keyword(s):  
Temporal Constraints ◽  
Temporal Planning

scholarly journals Physically Based Soap Bubble Synthesis for VR

2021 ◽  
Vol 11 (7) ◽  
pp. 3090
Author(s):  
Sangwook Yoo ◽  
Cheongho Lee ◽  
Seongah Chin
Keyword(s):  
Virtual Reality ◽  
Virtual Space ◽  
Soap Bubble ◽  
Temporal Constraints ◽  
High Expectations ◽  
Soap Bubbles ◽  
Physical Motion ◽  
Head Mounted Display ◽  
Interesting Topic ◽  
Physically Based

To experience a real soap bubble show, materials and tools are required, as are skilled performers who produce the show. However, in a virtual space where spatial and temporal constraints do not exist, bubble art can be performed without real materials and tools to give a sense of immersion. For this, the realistic expression of soap bubbles is an interesting topic for virtual reality (VR). However, the current performance of VR soap bubbles is not satisfying the high expectations of users. Therefore, in this study, we propose a physically based approach for reproducing the shape of the bubble by calculating the measured parameters required for bubble modeling and the physical motion of bubbles. In addition, we applied the change in the flow of the surface of the soap bubble measured in practice to the VR rendering. To improve users’ VR experience, we propose that they should experience a bubble show in a VR HMD (Head Mounted Display) environment.

scholarly journals A Study about the Temporal Constraints on the Martian Yardangs’ Development in Medusae Fossae Formation

2021 ◽  
Vol 13 (7) ◽  
pp. 1316
Author(s):  
Jia Liu ◽  
Zongyu Yue ◽  
Kaichang Di ◽  
Sheng Gou ◽  
Shengli Niu
Keyword(s):  
Size Distribution ◽  
Indirect Method ◽  
Common Method ◽  
Planetary Surface ◽  
Temporal Constraints ◽  
History Of Development ◽  
Long Duration ◽  
History Of ◽  
Dating Method

The age of Mars yardangs is significant in studying their development and the evolution of paleoclimate conditions. For planetary surface or landforms, a common method for dating is based on the frequency and size distribution of all the superposed craters after they are formed. However, there is usually a long duration for the yardangs’ formation, and they will alter the superposed craters, making it impossible to give a reliable dating result with the method. An indirect method by analyzing the ages of the superposed layered ejecta was devised in the research. First, the layered ejecta that are superposed on and not altered by the yardangs are identified and mapped. Then, the ages of the layered ejecta are derived according to the crater frequency and size distribution on them. These ages indicate that the yardangs ceased development by these times, and the ages are valuable for studying the evolution of the yardangs. This indirect dating method was applied to the areas of Martian yardangs in the Medusae Fossae Formation (MFF). The ages of the selected six layered ejecta range from ~0.50 Ga to ~1.5 Ga, indicating that the evolution of the corresponding yardangs had been ceased before these times. Analysis of more layered ejecta craters and superposed yardangs implies that yardangs in the MFF have a long history of development and some yardangs are still in active development.

scholarly journals Evaluation of Static Mapping for Dynamic Space-Shared Multi-task Processing on FPGAs

2021 ◽  
Author(s):  
Umar Ibrahim Minhas ◽  
Roger Woods ◽  
Georgios Karakonstantis
Keyword(s):  
High Performance ◽  
Design Space Exploration ◽  
Design Space ◽  
System Throughput ◽  
Design Parameters ◽  
Temporal Constraints ◽  
Shared Resources ◽  
Task Processing ◽  
High Level ◽  
Performance Computing

AbstractWhilst FPGAs have been used in cloud ecosystems, it is still extremely challenging to achieve high compute density when mapping heterogeneous multi-tasks on shared resources at runtime. This work addresses this by treating the FPGA resource as a service and employing multi-task processing at the high level, design space exploration and static off-line partitioning in order to allow more efficient mapping of heterogeneous tasks onto the FPGA. In addition, a new, comprehensive runtime functional simulator is used to evaluate the effect of various spatial and temporal constraints on both the existing and new approaches when varying system design parameters. A comprehensive suite of real high performance computing tasks was implemented on a Nallatech 385 FPGA card and show that our approach can provide on average 2.9 × and 2.3 × higher system throughput for compute and mixed intensity tasks, while 0.2 × lower for memory intensive tasks due to external memory access latency and bandwidth limitations. The work has been extended by introducing a novel scheduling scheme to enhance temporal utilization of resources when using the proposed approach. Additional results for large queues of mixed intensity tasks (compute and memory) show that the proposed partitioning and scheduling approach can provide higher than 3 × system speedup over previous schemes.

scholarly journals Resolving Phylogenetic Relationships within Passeriformes Based on Mitochondrial Genes and Inferring the Evolution of Their Mitogenomes in Terms of Duplications

2019 ◽  
Vol 11 (10) ◽  
pp. 2824-2849 ◽  
Author(s):  
Paweł Mackiewicz ◽  
Adam Dawid Urantówka ◽  
Aleksandra Kroczak ◽  
Dorota Mackiewicz
Keyword(s):  
Phylogenetic Analyses ◽  
Mitochondrial Genes ◽  
The Other ◽  
Phylogenetic Position ◽  
Evolutionary Relationships ◽  
Mitochondrial Genomes ◽  
Ancestral State ◽  
Phylogenetic Information ◽  
Long Time ◽  
Tree Topologies

Abstract Mitochondrial genes are placed on one molecule, which implies that they should carry consistent phylogenetic information. Following this advantage, we present a well-supported phylogeny based on mitochondrial genomes from almost 300 representatives of Passeriformes, the most numerous and differentiated Aves order. The analyses resolved the phylogenetic position of paraphyletic Basal and Transitional Oscines. Passerida occurred divided into two groups, one containing Paroidea and Sylvioidea, whereas the other, Passeroidea and Muscicapoidea. Analyses of mitogenomes showed four types of rearrangements including a duplicated control region (CR) with adjacent genes. Mapping the presence and absence of duplications onto the phylogenetic tree revealed that the duplication was the ancestral state for passerines and was maintained in early diverged lineages. Next, the duplication could be lost and occurred independently at least four times according to the most parsimonious scenario. In some lineages, two CR copies have been inherited from an ancient duplication and highly diverged, whereas in others, the second copy became similar to the first one due to concerted evolution. The second CR copies accumulated over twice as many substitutions as the first ones. However, the second CRs were not completely eliminated and were retained for a long time, which suggests that both regions can fulfill an important role in mitogenomes. Phylogenetic analyses based on CR sequences subjected to the complex evolution can produce tree topologies inconsistent with real evolutionary relationships between species. Passerines with two CRs showed a higher metabolic rate in relation to their body mass.

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