Operational Walking Dynamics of Crowds Modeled with Linear Regression

2017 ◽  
Vol 2623 (1) ◽  
pp. 90-97
Author(s):  
Dorine C. Duives ◽  
Winnie Daamen ◽  
Serge P. Hoogendoorn
Keyword(s):  
Linear Regression ◽  
Walking Speed ◽  
Simulation Models ◽  
Combined Effect ◽  
The Other ◽  
Pedestrian Flow ◽  
Time Headway ◽  
Close Proximity ◽  
Walking Dynamics ◽  
First Time

In this study the influence of interaction characteristics on operational walking dynamics within a crowd—specifically the influence of the distance headway, time headway, angle of sight, angle of interaction, walking speed, and number of pedestrians located nearby on a pedestrian’s change in speed and direction—is investigated. To the authors’ best knowledge, this is the first time that the combined effect of the characteristics of interactions between pedestrians on the operational walking dynamics of pedestrians has been quantified. The walking speed and the number of pedestrians in close proximity were found to influence the adaptation of speed and direction. The other characteristics of the interaction affect either the change in speed (i.e., distance headway and interaction angle) or the change in direction (i.e., time headway and angle of sight). The results of this study strongly indicate that the density experienced by pedestrians is not the only characteristic of the crowd that affects pedestrians’ operational walking dynamics. Consequently, to model crowd movements correctly, the other characteristics of the interaction must also be taken into account in pedestrian flow theory and simulation models.

The Uncertainty and Uncoordination of Mariners' Behaviour in Collision Avoidance at Sea

1995 ◽  
Vol 48 (3) ◽  
pp. 425-435 ◽  
Author(s):  
J. Zhao ◽  
W. G. Price ◽  
P. A. Wilson ◽  
M. Tan
Keyword(s):  
Decision Making ◽  
Simulation Model ◽  
Collision Avoidance ◽  
Simulation Models ◽  
Fuzzy Programming ◽  
Assessment Model ◽  
The Other ◽  
Entropy Theory ◽  
Close Proximity ◽  
Decision Making Model

It is well known that many collisions occur because one ship turns right whilst the other turns left when in close proximity to one another. Little is known as to why this occurs and, although some simulation models have been established using entropy theory, the problem remains unsolved.In this paper, an assessment model for uncertainty is reviewed briefly. The concepts of uncertainty and uncoordination of mariners' behaviour in collision avoidance are discussed. A simulation model in conjunction with a DCPA (distance to the closest point of approach) decision-making model using fuzzy programming is introduced to discuss coordination.

scholarly journals Practical Dynamical-Statistical Reconstruction of Ocean’s Interior from Satellite Observations

2021 ◽  
Vol 13 (24) ◽  
pp. 5085
Author(s):  
Hengqian Yan ◽  
Ren Zhang ◽  
Huizan Wang ◽  
Senliang Bao ◽  
Chengzu Bai
Keyword(s):  
Random Forest ◽  
Linear Regression ◽  
Satellite Data ◽  
Satellite Observations ◽  
The Other ◽  
Practical Application ◽  
Robust Performance ◽  
Statistical Reconstruction ◽  
Argo Profiles ◽  
First Time

The algorithms based on Surface Quasi-Geostrophic (SQG) dynamics have been developed and validated by many researchers through model products, however it is still doubtful whether these SQG-based algorithms are worth using in terms of observed data. This paper analyzes the factors impeding the practical application of SQG and makes amends by a simple “first-guess (FG) framework”. The proposed framework includes the correction of satellite salinity and the estimation of the FG background, making the SQG-based algorithms applicable in realistic circumstances. The dynamical-statistical method SQG-mEOF-R is thereafter applied to satellite data for the first time. The results are compared with two dynamical algorithms, SQG and isQG, and three empirical algorithms, multivariate linear regression (MLR), random forest (RF), and mEOF-R. The validation against Argo profiles showed that the SQG-mEOF-R presents a robust performance in mesoscale reconstruction and outperforms the other five algorithms in the upper layers. It is promising that the SQG-mEOF-R and the FG framework are applicable to operational reconstruction.

scholarly journals A Study of Blockage Effects at the Wind Turbine and Wind Farm Scales

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6124
Author(s):  
Mihaela Popescu ◽  
Tore Flåtten
Keyword(s):  
Energy Balance ◽  
Wind Turbine ◽  
Power Output ◽  
Wind Farm ◽  
Local Scale ◽  
Combined Effect ◽  
The Other ◽  
Energy Yield ◽  
Farm Scale ◽  
First Time

The paper provides novel insights into the physics behind the wind turbine and wind farm blockages as well as their effects on the energy yield based on the momentum and energy balance. The current work presents blockage effects at two scales: the local scale and the wind farm scale. We clarify the combined effect of local blockages when more than one turbine is present. The work demonstrates why two turbines, which are positioned one behind the other, induce a mutual decrease in energy yield. When the turbines are placed in a row, there is an increase of energy from the end to the middle of the row because of the restriction of the expansion flow. As in the case of two turbines placed behind each other, back rows induce a power decrease for the rows in front of them and the effect increases from the edge to the center. The work also elucidates for the first time how the power output of an isolated row has a maximum in the center, whereas, in a wind farm, wind turbines on the edge of the first row could have maximum power. The findings are supported by CFD.

scholarly journals NEW CHROMOSOME COUNTS OF ASIAN COSTACEAE AND INITIAL INSIGHTS INTO THE GENOME EVOLUTION OF THE FAMILY

2021 ◽  
Vol 78 ◽  
pp. 1-13
Author(s):  
Pim H Van Caspel ◽  
Axel Dalberg Poulsen ◽  
Michael Möller
Keyword(s):  
Phylogenetic Tree ◽  
Genome Evolution ◽  
Diploid Number ◽  
Parallel Evolution ◽  
The Other ◽  
Chromosome Counts ◽  
Comprehensive Review ◽  
The Family ◽  
Close Proximity ◽  
First Time

Chromosome counts were obtained from six species of Costaceae from Asia. Our count of 2n = 18 for Cheilocostus speciosus confirms previous counts, and the other five counts have been made for the first time (Cheilocostus borneensis, Cheilocostus globosus, Cheilocostus sopuensis, Costus muluensis and Paracostus sp.). These chromosome counts reveal two somatic numbers, 2n = 18 and 2n = 36, of which the former is a new diploid number for the genus Paracostus. A comprehensive review of existing counts was conducted through literature and database searches. Mapping of these on a published comprehensive phylogenetic tree suggests that the diploid count of 2n = 18 is probably ancestral in the Costaceae, with repeated parallel evolution of tetraploidy and one case of octoploidy. The existence of triploid counts in several lineages harbouring polyploids suggests that diploids and tetraploids may exist in close proximity, and that crosses or meioticirregularities may lead to triploid genotypes occurring frequently.

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

Sphagnum mosses (Sphagnaceae, Bryophyta) of mires Chefandzar and Masota in North Ossetia (Caucasus)

2018 ◽  
Vol 52 (2) ◽  
pp. 455-462 ◽  
Author(s):  
G. Ya. Doroshina ◽  
I. A. Nikolajev
Keyword(s):  
Plant Communities ◽  
The Other ◽  
North Caucasus ◽  
Sphagnum Mosses ◽  
Greater Caucasus ◽  
The North ◽  
First Time ◽  
North Ossetia

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.

An Epistemological Criticism of Social Entrepreneurship: Is Social Entrepreneurship a Sound Scientific Field of Research

2018 ◽  
Author(s):  
Amir Forouharfar
Keyword(s):  
Social Entrepreneurship ◽  
Social Constructivism ◽  
Social Epistemology ◽  
American English ◽  
Meta Analysis ◽  
Research Question ◽  
Knowledge Structure ◽  
Scientific Field ◽  
The Other ◽  
First Time

The paper was shaped around the pivotal question: Is SE a sound and scientific field of research? The question has given a critical tone to the paper and has also helped to bring out some of the controversial debates in the realm of SE. The paper was organized under five main discussions to be able to provide a scientific answer to the research question: (1)<b> </b>is “social entrepreneurship” an oxymoron?, (2) the characteristics of SE knowledge, (3) sources of social entrepreneurship knowledge, (4) SE knowledge: structure and limitations and (5) contributing epistemology-making concepts for SE.<b> </b>Based on the sections,<b> </b>the study relied on the relevant philosophical schools of thought in <i>Epistemology </i>(e.g. <i>Empiricism</i>, <i>Rationalism</i>, <i>Skepticism</i>, <i>Internalism</i> vs. <i>Externalism</i>,<i> Essentialism, Social Constructivism</i>, <i>Social Epistemology, etc.</i>) to discuss these controversies around SE and proposes some solutions by reviewing SE literature. Also, to determine the governing linguistic discourse in the realm of SE, which was necessary for our discussion,<i> Corpus of Contemporary American English (COCA)</i> for the first time in SE studies was used. Further, through the study, SE buzzwords which constitute SE terminology were derived and introduced to help us narrowing down and converging the thoughts in this field and demarking the epistemological boundaries of SE. The originality of the paper on one hand lies in its pioneering discussions on SE epistemology and on the other hand in paving the way for a construction of sound epistemology for SE; therefore in many cases after preparing the philosophical ground for the discussions, it went beyond the prevalent SE literature through meta-analysis to discuss the cases which were raised. The results of the study verified previously claimed embryonic pre-paradigmatic phase in SE which was far from a sound and scientific knowledge, although the scholarly endeavors are the harbingers of such a possibility in the future which calls for further mature academic discussion and development of SE knowledge by the SE academia.

ANALISIS VARIABEL YANG BERPENGARUH TERHADAP KINERJA PERUSAHAAN DI BURSA EFEK INDONESIA

2019 ◽  
Author(s):  
SUSENO - SUSENO
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Stock Exchange ◽  
T Test ◽  
The Other ◽  
Financial Leverage ◽  
F Test ◽  
Research Results ◽  
Independent Variables ◽  
Influential Variable

ANALISIS VARIABEL YANG BERPENGARUH TERHADAP KINERJA PERUSAHAAN DI BURSA EFEK INDONESIAOleh : Suseno STIE SATRIA Purwokerto ABSTRACT The aims of the research are (1) to analyze influence of age, scale, financial leverage, and profitability to performance of firms at The Indonesian Stock Exchange. (2) to determine the most influential variable on the performance of the firms. Hypotheses proposed in this research were: (1) Age, Scales, Financial Leverage, Profitability influences the performance of firms, (2) Age influences the performance of firms, (3) Scales influences the performance of firms, (4) Financial Leverage influences the performance of firms, (5) Profitability influences the performance of firms. Instrument of analysis employed in the research was multiple linear regression with t test and F test.The results of analyses of t test showed that profitability did not influence the performance of the firms. It was indicated by the value of computed t which was smaller than the value of t table. Meanwhile, the t test of age, scale and financial leverage indicated that the value of computed t &gt; t table. It means that these variables (scale and financial leverage) influenced the performance of the firms. The F test showed that the independent variables of age, scale, financial leverage and profitability as a whole significantly influenced the performance of the firms. It was indicated by the calculated F &gt; the value of F table, the value the age computed t which was smaller than the value of -t table..Based on the research results that age and profitability do not influence the performance of the firms, it is suggested that investors should not pay any attention to those variables. On the other hand, they should pay attention to the variables of scale and financial leverage. It is recommended that for further research should include longer periode of the sample.

A Nabatean port on the Red Sea: note on the pottery finds from al-Qusayr (al-Wajh, Saudi Arabia)

2020 ◽  
Author(s):  
Caroline Durand
Keyword(s):  
Saudi Arabia ◽  
19Th Century ◽  
Red Sea ◽  
Point Of View ◽  
The Other ◽  
Trade Routes ◽  
Other Hand ◽  
Roman Egypt ◽  
Pottery Sherds ◽  
First Time

Al-Qusayr is located 40 km south of modern al-Wajh, roughly 7 km from the eastern Red Sea shore. This site is known since the mid-19th century, when the explorer R. Burton described it for the first time, in particular the remains of a monumental building so-called al-Qasr. In March 2016, a new survey of the site was undertaken by the al-‘Ula–al-Wajh Survey Project. This survey focused not only on al-Qasr but also on the surrounding site corresponding to the ancient settlement. A surface collection of pottery sherds revealed a striking combination of Mediterranean and Egyptian imports on one hand, and of Nabataean productions on the other hand. This material is particularly homogeneous on the chronological point of view, suggesting a rather limited occupation period for the site. Attesting contacts between Mediterranean merchants, Roman Egypt and the Nabataean kingdom, these new data allow a complete reassessment of the importance of this locality in the Red Sea trade routes during antiquity.

Status of Family Fissidentaceae in Gujarat

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
D.G. Shah ◽  
D.N. Mehta ◽  
R.V. Gujar
Keyword(s):  
Distinct Species ◽  
The State ◽  
The Other ◽  
Land Plants ◽  
Reproductive Structures ◽  
The Family ◽  
The Status ◽  
Vegetative Characters ◽  
First Time ◽  
Different Parts

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.

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