scholarly journals Structural characteristics and proximity comparison of China’s urban innovation cooperation network

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255443
Author(s):  
Yingying Yuan ◽  
Zenglin Han
Keyword(s):  
Development Stage ◽  
Spatial Data Analysis ◽  
Geographical Proximity ◽  
High Quality ◽  
Initial Development ◽  
Edge Structure ◽  
Cooperation Network ◽  
Network Proximity ◽  
Innovation Cooperation ◽  
Cooperation System

How to promote and improve the level of urban innovation cooperation is a major issue in China’s current high-quality economic development. Thus, enhancing innovation ability is essential to achieving high-quality economic growth under the "new normal". Based on the data of Chinese invention patents from 1985 to 2017, this paper analyzes the characteristics of China’s urban innovation cooperation network and the different roles of proximity by using social network analysis and exploratory spatial data analysis methods. The analysis results show that: (1) On the whole, the development of China’s urban innovation cooperation network is characterized by stages (initial development stage, rapid development stage, and gradual decline stage); The urban innovation cooperation network has strong connectivity and centripetal concentration but its imbalance needs to be further improved; The degree of urban participation has gradually increased, consolidating the stability of the network structure. (2) The centrality of urban innovation cooperation network has obvious characteristics of administrative center orientation, coastal areas orientation, and ‘strong east and weak west’; Beijing is the center and bridge of the network, and the network flattening characteristics are obvious; A hierarchical ‘core-edge’ structure is gradually formed for the urban innovation cooperation network, and the pyramid structure with Beijing standing at the top is being consolidated. (3) The geographical proximity presents a significant global spatial positive correlation, while the network proximity and pure network proximity have a more significant global spatial negative correlation; The local spatial autocorrelation of China’s urban innovation cooperation system based on network proximity is more obvious and identifiable than that based on the geographical proximity, which better reflects the new development model of "relationship economy".

Prognostic criteria for Polar Lows

2021 ◽  
Author(s):  
Natalia Vazaeva ◽  
Otto Chkhetiani ◽  
Michael Kurgansky
Keyword(s):  
Numerical Simulation ◽  
Wind Velocity ◽  
Large Scale ◽  
Satellite Image ◽  
Development Stage ◽  
Mature Stage ◽  
Initial Development ◽  
Polar Lows ◽  
Prognostic Criteria ◽  
Main Challenge

<p>Polar lows (PLs) are important mesoscale (horizontal diameter up to 1000 km) maritime weather systems at high latitudes, forming pole ward from the polar front. We consider the possible prognostic criteria of PLs, in particular, the kinematic helicity as a quadratic characteristic related to the integral vortex formations and the kinematic vorticity number (KVN). To calculate such characteristics we use reanalysis data and the results of numerical simulation with the WRF-ARW model (Version 4.1.) for the PLs over the Nordic (Norwegian and Barents) seas. For comparison, experimental data are used.</p><p>Our estimate of helicity is based on the connection of an integral helicity (IH) in the Ekman layer with the geostrophic wind velocity, due to the good correlation between IH and half the sum of the wind velocity squared. We have chosen IH averaged over preselected area covering the locality of PLs genesis. This area was moving along with the centre of PL during the numerical simulation.</p><p>The genesis of PLs can be divided into three stages: (i) an initial development stage, in which a number of small vortices appear in a shear zone; (ii) a late development stage, characterized by the merger of vortices; (iii) a mature stage, in which only a single PL is present. Approximately one day before PL formation, a significant increase in helicity was observed. The average helicity bulk density of large-scale motions has values of 0.3 – 0.4 ms<sup>-2</sup>. The local changes in helicity are adjacent to the front side of the PLs. The IH criterion described facilitates the identification of the PLs genesis area. For a more detailed analysis of the PL genesis, it is recommended to apply KVN, which is the additional indicator of PL size and intensity. At the moment of maximum intensity of PLs KVN can reach values of 12 – 14 units. The advantage of using KVN is also in its clear change directly in the centre of the emerging PLs, which allows to precisely indicates the limits of the most intense part of PLs.</p><p>The main challenge is to make the operational forecast of PLs possible through the selection of the prognostic integral characteristics of PLs, sufficient for PLs identification and for analysis of their size and intensity in a convenient, usable and understandable way. The criteria associated with vorticity and helicity are reflected in the PLs genesis and development quite clearly. At this time, such a claim is only a hypothesis, which must be tested using a larger set of cases. Future work will need to extend these analyses to other active PL basins. Also, it would be interesting to compare the representation of PLs by using any other criteria. It is intended to use our combined criteria as a precursor to machine learning-based PLs identification procedure where satellite image analysis and capture of particular cloud patterns are currently applied in most of the cases. It would eliminate the time consuming first stage of collecting data sets.</p><p>This work was supported by the Russian Science Foundation (project No. 19-17-00248).</p>

scholarly journals Efecto de medicamentos homeopáticos en plantas de tomate (Solanum lycopersicum L.)

2020 ◽  
Vol 38 (1) ◽  
pp. 103
Author(s):  
Fernando Abasolo Pacheco ◽  
Boris Bonilla Montalván ◽  
Cesar Bermeo Toledo ◽  
Yarelys Ferrer Sánchez ◽  
Andy Jafet Ramirez Castillo ◽  
...  
Keyword(s):  
Root Biomass ◽  
Block Design ◽  
Development Stage ◽  
Stem Length ◽  
Control Treatment ◽  
Leaf Biomass ◽  
Control Group ◽  
Vegetative Development ◽  
Initial Development ◽  
Development Stages

Agrochemical use in horticultural cultivations generates negative effects, thus the need for searching to decrease or eliminate its use by means of other less toxic techniques. Agricultural homeopathy represents an alternative for ecological agriculture, impacting positively in cultivation development. The effect of four homeopathic medicines for human use were assessed in two centesimal dynamizations (7CH and 13CH) [(Silicea Terra (SiT), Natrum muriaticum (NaM), Zincum phosphoricum (ZiP) and Phosphoricum acidum (PhA)], and a control treatment (distilled water) on tomato plant germination, emergence, and initial development. The treatments were established under a randomized complete block design with three repiclates. Germination and emergence rate and percentage and morphometric variables (plant height, radicle length, dry and wet weight) were assessed, including the variables in stem diameter and wet and dry leaf weight, number of branches, leaves, and buds in the vegetative development stage. Signif icant differences were observed in all the morphometric variables assessed in function of the different development stages, homeopathic medicines, and their different dynamizations. During germination, greater growth in stem length was observed with ZiP-7CH (5.5 ± 0.98 cm) compared to the control group (4.3 ± 1.10 cm). During the emergence stage, the treatments SiT-7CH (6.6 ± 1.11 cm) and ZiP-7CH (5.9 ± 1.41 cm) increased stem length signif icantly whereas with PhA-7CH, the best effects were obtained in the variables assessed during the vegetative development stage, LT (94 ± 8.31 cm), leaf number (No hojas) (131 ± 27.71), fresh stem biomass (BFT) (17.20 ± 2.45 g), wet leaf biomass (BFH) (30 ± 7.72 g), dry leaf biomass (BSH) (2 ± 0.61 g), fresh root biomass (BFR) (10 ± 6.26 g), dry root biomass (BSR) (1 ± 0.43 g), and number of flower buds (No H) (6 ± 7.10). The homeopathic medicines applied impacted positively during the initial and vegetative development stages of tomato under controlled conditions. This research study represents and advance in the sustainable management of tomato cultivation.

scholarly journals Improved Compact Cuckoo Search Algorithm Applied to Location of Drone Logistics Hub

Mathematics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 333 ◽  
Author(s):  
Jeng-Shyang Pan ◽  
Pei-Cheng Song ◽  
Shu-Chuan Chu ◽  
Yan-Jun Peng
Keyword(s):  
Rural Areas ◽  
Large Scale ◽  
Search Algorithm ◽  
Cuckoo Search ◽  
Development Stage ◽  
Cuckoo Search Algorithm ◽  
Initial Development ◽  
Logistics Systems ◽  
The Cost ◽  
The Village

Drone logistics can play an important role in logistics at the end of the supply chain and special environmental logistics. At present, drone logistics is in the initial development stage, and the location of drone logistics hubs is an important issue in the optimization of logistics systems. This paper implements a compact cuckoo search algorithm with mixed uniform sampling technology, and, for the problem of weak search ability of the algorithm, this paper combines the method of recording the key positions of the search process and increasing the number of generated solutions to achieve further improvements, as well as implements the improved compact cuckoo search algorithm. Then, this paper uses 28 test functions to verify the algorithm. Aiming at the problem of the location of drone logistics hubs in remote areas or rural areas, this paper establishes a simple model that considers the traffic around the village, the size of the village, and other factors. It is suitable for selecting the location of the logistics hub in advance, reducing the cost of drone logistics, and accelerating the large-scale application of drone logistics. This paper uses the proposed algorithm for testing, and the test results indicate that the proposed algorithm has strong competitiveness in the proposed model.

The Role of Shearwise and Transverse Quasigeostrophic Vertical Motions in the Midlatitude Cyclone Life Cycle

2006 ◽  
Vol 134 (4) ◽  
pp. 1174-1193 ◽  
Author(s):  
Jonathan E. Martin
Keyword(s):  
Life Cycle ◽  
Vertical Motion ◽  
Development Stage ◽  
Life Cycles ◽  
Vertical Shear ◽  
Mature Stage ◽  
Motion Field ◽  
Initial Development ◽  
Frontal Zones ◽  
Oriented Parallel

Abstract The total quasigeostrophic (QG) vertical motion field is partitioned into transverse and shearwise couplets oriented parallel to, and along, the geostrophic vertical shear, respectively. The physical role played by each of these components of vertical motion in the midlatitude cyclone life cycle is then illustrated by examination of the life cycles of two recently observed cyclones. The analysis suggests that the origin and subsequent intensification of the lower-tropospheric cyclone responds predominantly to column stretching associated with the updraft portion of the shearwise QG vertical motion, which displays a single, dominant, middle-tropospheric couplet at all stages of the cyclone life cycle. The transverse QG omega, associated with the cyclones’ frontal zones, appears only after those frontal zones have been established. The absence of transverse ascent maxima and associated column stretching in the vicinity of the surface cyclone center suggests that the transverse ω plays little role in the initial development stage of the storms examined here. Near the end of the mature stage of the life cycle, however, in what appears to be a characteristic distribution, a transverse ascent maximum along the western edge of the warm frontal zone becomes superimposed with the shearwise ascent maximum that fuels continued cyclogenesis. It is suggested that use of the shearwise/transverse diagnostic approach may provide new and/or supporting insight regarding a number of synoptic processes including the development of upper-level jet/front systems and the nature of the physical distinction between type A and type B cyclogenesis events.

A Study of Burr Formation Processes Using the Finite Element Method: Part I

1999 ◽  
Vol 122 (2) ◽  
pp. 221-228 ◽  
Author(s):  
I. W. Park ◽  
D. A. Dornfeld
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Metal Cutting ◽  
Ductile Failure ◽  
Development Stage ◽  
Burr Formation ◽  
The Finite Element Method ◽  
Initial Development ◽  
Final Development ◽  
Element Method

A finite element model of orthogonal metal cutting including burr formation is presented. A metal-cutting simulation procedure based on a ductile failure criterion is proposed for the purpose of better understanding the burr formation mechanism and obtaining a quantitative analysis of burrs using the finite element method. In this study, the four stages of burr formation, i.e., initiation, initial development, pivoting point, and final development stages, are investigated based on the stress and strain contours with the progressive change of geometry at the edge of the workpiece. Also, the characteristics of thick and thin burrs are clarified along with the negative deformation zone formed in front of the tool edge in the final development stage. [S0094-4289(00)00702-7]

scholarly journals User Perspective Towards M-banking in Bangladesh: A Case Study Based on University Students

2020 ◽  
Vol 4 (2) ◽  
pp. 1-5
Author(s):  
Md Tafsir Alam ◽  
Syeeda Raisa Maliha ◽  
Mustafa Nizamul Aziz
Keyword(s):  
Significant Positive Correlation ◽  
Emerging Market ◽  
Listed Companies ◽  
Development Stage ◽  
Management Team ◽  
Senior Management ◽  
Academic Experience ◽  
High Quality ◽  
Positive Correlation ◽  
Innovation Ability

In recent years, as the largest emerging market, China's economic development has gradually shifted from the high growth stage to the high-quality development stage. The company is an essential micro-subject of macroeconomic activities, and an entrepreneur's academic background is a critical factor in achieving high-quality corporate development. This study takes the data of IT listed companies in China from 2012 to 2017 as the sample, Screening research samples based on academic experience requirements based on requirements for current or former teaching and research positions in universities, then makes an empirical analysis on the connection between academic executives and companies innovation ability. The results indicate that there is a significant positive correlation between executive academic experience and the company's innovation ability, i.e., academics-type. There is also a significant positive correlation between the average tenure of executives and innovation ability, which still holds after the robustness test. Researching the relationship between the academic experience of the executives of listed companies and their innovation ability can not only enrich the research on the characteristics of the senior management team, but also provide theoretical guidance for the construction of senior management team, and provide a few suggestions for the improvement of innovation ability and the formulation of government-related policies.  

Millimeter Wave Communication Networks

2021 ◽  
Vol 12 (3) ◽  
pp. 138-153
Author(s):  
Umar Farooq ◽  
Ghulam Mohammad Rather
Keyword(s):  
Communication Networks ◽  
Millimeter Wave ◽  
Wireless Systems ◽  
Development Stage ◽  
Practical Implementation ◽  
Initial Development ◽  
High Data ◽  
Potential Applications ◽  
Technical Challenges ◽  
Near Future

Millimeter wave (MMW) communication is a key technology to support the high data rate requirements of next generation networks and cope up the spectrum scarcity and capacity limitations of current wireless systems and hence enable a plethora of applications. However, this technology is in its initial development stage, and there are various technical challenges in its practical implementation that need to be addressed before its successful deployment. This paper reviews the state of the art in MMW communications and provides in-depth detail of the basic propagation characteristics of MMWs in different operation scenarios. The paper also analyses the various technical challenges of MMW communication networks envisaged in its implementation and highlights the design choices proposed so far to address these challenges. Finally, some of the potential applications of MMW communications that may emerge in the near future are also discussed.

Effect of small impediments on channel morphology – intermittent rivers in Brazilian drylands.

2021 ◽  
Author(s):  
André Branco ◽  
Jonas Souza
Keyword(s):  
Rural Areas ◽  
River Flow ◽  
Hydrological Regime ◽  
Development Stage ◽  
Channel Morphology ◽  
Small Rivers ◽  
Sediment Retention ◽  
Initial Development ◽  
Longitudinal Connectivity ◽  
Intermittent Rivers

<p>Land use on rural drylands has as its occupation process developing a hydric security and transportations infrastructure system. Dryland tropical systems present fluvial hydrological regime controlled by precipitation inputs, with few or none springs, showing ephemeral and intermittent rivers. Floodway crossings are a widespread infrastructure, on the countryside road network, to cross small creeks, especially intermittent and ephemeral rivers during the rainy seasons. Floodways are concrete or rock block structure, with or without culverts, that allows the river flow goes through or over it. They are part of a set of small longitudinal impediments, like small earth dams and check-dams, and can significantly impact the connectivity, notably by the high density of these impediments on rural areas. This research analysed the effect of floodways crossing on longitudinal connectivity of intermittent small rivers, focusing on morphological and sedimentological impacts in Brazilian Dryland. We analysed four floodways crossing with culverts installed on sandbed intermittent rivers, with upstream catchment are from 10 Km² to 130 Km². The analyses were based on rainfall data, lateral and longitudinal topographic profiles, generate by UAV surveys; and sedimentological samples of upstream and downstream of each structure. The Effective Catchment Area (ECA) was the first step to understand that several dams, and other longitudinal disconnect elements, decrease the ECA sharply, from 2 Km² to 38 Km² of the floodways analysed. Consequently, it affects the magnitude and frequency of water and especially sediment that reaches the floodway crossings. The results reveal the increase of upstream local base level, affecting 500 to 1000 meters, and coarse sediment retention, which is 1.7 to 3.6 times the standard percentage of very coarse sand and gravel. The retained sediment can be re-worked (reconnect) by extreme rainfall/discharges events, recurrence 0,22/year, and when the silting surface reaches the culvert level. The evolution of the upstream silting process is controlled not only by construction age but also by ECA spatiality and changes, and frequency and magnitude of rainfall/discharges events. The results discussion enabled developing an evolution model based on four stages: Installation, Adaptation, Coexistence, and Silting up. The Installation stage is the building process that locally deconfigures the channel morphology and, sometimes, inserts unfamiliar materials on channels. The Adaptation Stage starts with the first flow events that recreate a channel morphology but affected by the floodway, with the beginning of enhanced upstream sedimentation and downstream erosion. The Coexistence stage the disconnectivity effect is evident with the upstream sedimentation moving upstream. The downstream erosion creates a pool, expanding the floodway/riverbed height gap, and progressively increasing the vertical incision downstream. Lastly, when the sedimentation reaches the culvert level or the floodway, sediment retention decreases, and most of the transported sediment overpass the impediment. The frequency and magnitude of flow events control the time to progress through each stage, remembering the ECA analysis importance over space and time. This proposed model that still on initial development stage can help the integrative environmental management on areas impacted by widespread small longitudinal impediments.</p>

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