regular pattern
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2022 ◽  
Vol 216 ◽  
pp. 105980
Author(s):  
Zeyang Li ◽  
Weixin Luan ◽  
Xintong Wang ◽  
Shulin Wan ◽  
Min Su ◽  
...  

Author(s):  
Е. Е. Антонов

Статья представляет собой часть серии, посвященной планировкам позднескифских поселений Северо-Западного Крыма. Ее цель - выделение главных характеристик позднескифской застройки в регионе, проверка рабочей гипотезы о преемственности планировок на протяжении всего «позднескифского» периода, сравнение облика поселений Северо-Западного Крыма с синхронными памятниками соседних регионов. Тема настоящей статьи - планировки второй половины I в. до н. э. - первой четверти I в. н. э. Это время можно признать периодом расцвета поселений. Они достигают максимальных размеров, вокруг укреплений формируются «посады». Планировки поселений выглядят упорядоченными. Единицами застройки выступают многокомнатные дома, которые блокируются в кварталы. Характерная черта - использование греческих сооружений. В начале периода поселения укреплены различными оборонительными сооружениями, к концу они полностью или частично теряют свое значение. The paper is one in a series exploring the layout of late Scythian settlements in northwestern Crimea. It is aimed to identify key characteristics of late Scythian buildings in the region, test the working hypothesis on continuity of layouts throughout the entire ‘late Scythian’ period, and compare the look of settlements in northwestern Crimea with that of contemporaneous sites in the neighboring regions. This paper focuses on settlement layout in the second half of the 1 century BC - first quarter of the 1 century AD. Settlements of that period reached peak in their development. Settlements reached maximum size, with trading quarters (suburbs) appearing around fortified settlements. The layout of a settlement appears to follow a regular pattern. Housing units are buildings with many rooms constructed in residential quarters. Settlement development is characterized by use of Greek constructions. Early in the period settlements were fortified with various defensive structures which lost their importance partly or completely.


2021 ◽  
Vol 10 ◽  
pp. 17-32
Author(s):  
Guido Fava ◽  
Việt Anh Đinh

The most advanced technique to evaluate different solutions proposed for a field development plan consists of building a numerical model to simulate the production performance of each alternative. Fields covering hundreds of square kilometres frequently require a large number of wells. There are studies and software concerning optimal planning of vertical wells for the development of a field. However, only few studies cover planning of a large number of horizontal wells seeking full population on a regular pattern. One of the criteria for horizontal well planning is selecting the well positions that have the best reservoir properties and certain standoffs from oil/water contact. The wells are then ranked according to their performances. Other criteria include the geometry and spacing of the wells. Placing hundreds of well individually according to these criteria is highly time consuming and can become impossible under time restraints. A method for planning a large number of horizontal wells in a regular pattern in a simulation model significantly reduces the time required for a reservoir production forecast using simulation software. The proposed method is implemented by a computer script and takes into account not only the aforementioned criteria, but also new well requirements concerning existing wells, development area boundaries, and reservoir geological structure features. Some of the conclusions drawn from a study on this method are (1) the new method saves a significant amount of working hours and avoids human errors, especially when many development scenarios need to be considered; (2) a large reservoir with hundreds of wells may have infinite possible solutions, and this approach has the aim of giving the most significant one; and (3) a horizontal well planning module would be a useful tool for commercial simulation software to ease engineers' tasks.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260629
Author(s):  
Yanhui Zhu ◽  
Kenji Minami ◽  
Yuka Iwahara ◽  
Kentaro Oda ◽  
Koichi Hidaka ◽  
...  

The Kuroshio Current can take two paths; usually it follows the regular pattern but occasionally it follows a pattern known as the large meander. In this study, we investigated the abundance of fish that migrate to coastal waters and the spatial distribution of fish schools under both Kuroshio patterns in Suzu district, Kochi prefecture, where the set net is the main fishery industry. We clarified the seasonal variation in the density and distribution of fish schools using a quantitative echo sounder. The effects of the Kuroshio large meander (LM) depended on the season. There was no effect of current pattern in summer or autumn, but in winter and spring the LM altered the marine environment and fish distributions. Cold water masses were formed in the survey area during winter and spring during the LM, and the water temperature dropped significantly compared with during the Kuroshio non-large meander (NLM). This altered the fish species and the distribution of fish schools in the survey area. The catches of Japanese horse mackerels (Trachurus japonicus) and Yellowtails (Seriola quinqueradiata) were much higher during the LM compared with those during the NLM. Unlike these two species, the small-sized pelagic fishes in spring has decreased significantly during the LM.


MAUSAM ◽  
2021 ◽  
Vol 60 (3) ◽  
pp. 309-316
Author(s):  
D. M. RASE ◽  
M. P. SHEVALE ◽  
S. I. M. RIZVI

Importance of monsoon depressions, Low Pressure Systems (LPS) and the number of LPS days on rainfall and hence indirectly on agriculture and hydrology, is well recognized.      In this paper the pattern of annual variability in these systems have been examined using data from 1901-2000. The above mentioned parameters have been subjected to decadal analysis to detect presence of any regular pattern. An attempt has been made to find its tendency with time.  Impact of these systems on central India rainfall has been determined and discussed.     The study endorses the earlier findings that there is a   decreasing trend in the frequency of depressions which has been compensated with increase in LPS days over Indian region in recent years.  The rainfall over central India is more significantly related with a number of LPS days over Indian region.


2021 ◽  
Vol Volume 13 ◽  
pp. 6891-6899
Author(s):  
Xi-Yu Yao ◽  
Yan Zhou ◽  
Shun-Jin Chen ◽  
Yu Wu ◽  
Cong Bian ◽  
...  

2021 ◽  
Vol 83 (10) ◽  
Author(s):  
Jonathan A. Sherratt ◽  
Quan-Xing Liu ◽  
Johan van de Koppel

AbstractSelf-organised regular pattern formation is one of the foremost examples of the development of complexity in ecosystems. Despite the wide array of mechanistic models that have been proposed to understand pattern formation, there is limited general understanding of the feedback processes causing pattern formation in ecosystems, and how these affect ecosystem patterning and functioning. Here we propose a generalised model for pattern formation that integrates two types of within-patch feedback: amplification of growth and reduction of losses. Both of these mechanisms have been proposed as causing pattern formation in mussel beds in intertidal regions, where dense clusters of mussels form, separated by regions of bare sediment. We investigate how a relative change from one feedback to the other affects the stability of uniform steady states and the existence of spatial patterns. We conclude that there are important differences between the patterns generated by the two mechanisms, concerning both biomass distribution in the patterns and the resilience of the ecosystems to disturbances.


2021 ◽  
Author(s):  
Kevin D. Gallagher ◽  
Madhav Mani ◽  
Richard W. Carthew

Pattern formation of biological structures involves the arrangement of different types of cells in an ordered spatial configuration. In this study, we investigate the mechanism of patterning the Drosophila eye into a precise triangular grid of photoreceptor clusters called ommatidia. Previous studies had led to a long-standing biochemical model whereby a reaction-diffusion process is templated by recently formed ommatidia to propagate a molecular prepattern across the eye epithelium. Here, we find that the templating mechanism is instead, mechanical in origin; newly born columns of ommatidia serve as a template to spatially pattern cell flows that move the cells in the epithelium into position to form each new column of ommatidia. Cell flow is generated by a pressure gradient that is caused by a narrow zone of cell dilation precisely positioned behind the growing wavefront of ommatidia. The newly formed lattice grid of ommatidia cells are immobile, deflecting and focusing the flow of other cells. Thus, the self-organization of a regular pattern of cell fates in an epithelium is mechanically driven.


Author(s):  
David F. Mora-Marín

Abstract This article examines two instances of metathesis that have occurred in Ch'ol (Mayan) since the late 18th century. While at first, they may seem to be cases of irregular, sporadic change, a closer look at constraints involving ejective consonants within disyllabic and trisyllabic roots or stems suggests that these cases conform to a regular pattern within Ch'ol, and more generally, Mayan languages, in which reflexes of *q’ or *k’ are preferred in medial position in disyllabic roots with a medial glottalized consonant. The data support Hume's (2004) attestation assumption for metathesis, as well as Hock's (1985) structural motivation.


2021 ◽  
Vol 7 (3) ◽  
pp. 97-108
Author(s):  
Pavlo Dziuba ◽  
Olena Pryiatelchuk ◽  
Denys Rusak

The paper is devoted to the study of risk and return tradeoff in the global equity market as well as particular market groups: developed, emerging and frontier markets. Impact of this tradeoff on international equity portfolio liabilities is explored. The study confirms the hypothesis that there are some specific patterns of risk and return tradeoff during crisis periods and periods of markets regular regime that substantially differ from each other and define global portfolio equity flows and liabilities in a specific way. The paper thus carries out its main objective that implies revealing these patterns with respective qualitative features and quantitative markers, specifying their implications for equity portfolio flows to markets of different types. Risks and returns for different market groups and global market as a whole are calculated for the period between 2002 and 2020 using standard methodology of contemporary portfolio theory and MSCI indices monthly values. The data for international equity portfolio liabilities as well as the share of particular market group in the global market are used as dependent variables. The latter are regressed by calculated risks and returns. Using the model results and some analytical developments, two patterns of risk/return tradeoff are discovered. The pattern attributable to regular market regimes is characterized by positive returns which is 1.51 % in average for the global market, 1.48 % for developed markets and 2.03 % for emerging markets. Risks in regular pattern are relatively small or moderate at the average level of 3.05 for the global market and are all below the median (3.48). Respective risks for developed and emerging markets are 3.02 and 4.54. The Sharpe ratios in regular pattern are positive at the average level of 0.60 for the global market, 0.57 and 0.45 for developed and emerging market groups respectively. The crisis pattern implies negative returns at the mean of -1.04 for the global market, -0.97 for the developed group and -1.35 for the emerging markets. High risks are all above the median and in average compile 5.5 for the global market, 5.47 for the developed markets and 6.68 for the emerging group. Sharpe ratios for this pattern are negative being equal to -0.19 in the mean. The average value is -0.18 for developed markets and it is -0.24 for emerging markets. Specific pattern of 2020 crisis should be settled out. Its main feature that substantially distinguishes it from other crises is the combination of highest risk level and the positive returns at the same time. Elaborated regression model confirms the direct impact of return and indirect impact of risk on global portfolio liabilities. The influence of risk for regular and crisis patterns does not differ substantially while the impact of return is much stronger during periods of increased volatility (respective model parameters are 3793.76 and 447.24). However, the discovered impact is much more reliable in crisis pattern that is supported by much higher determination ratio. Developed markets experience similar effects.


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