The Big-headed Ant Pheidole megacephala: a new threat to monsoonal northwestern Australia

1998 ◽  
Vol 4 (3) ◽  
pp. 250 ◽  
Author(s):  
Benjamin D. Hoffmann
Keyword(s):  
Agricultural Production ◽  
Large Scale ◽  
Foraging Ecology ◽  
Potential Threat ◽  
Pheidole Megacephala ◽  
Realistic Option ◽  
Northwestern Australia ◽  
Nature Park ◽  
And Control

The Big-headed Ant Pheidole megacephala is a major threat to native invertebrate assemblages and to agricultural production world-wide. This paper reviews its known biology including its foraging ecology, colony founding and dispersal behaviour. A case study is presented to illustrate its potential conservation significance for northern Australia. At Howard Springs Nature Park in the Darwin region of the Northern Territory, an infestation of P. megacephala was found to cover 25 ha and is continuing to spread, with its distribution centred on a rainforest patch. The abundance of P. megacephala within the rainforest was 37?110 times that of total native ant abundance at uninfested sites. Only two individuals of a single native ant species were found in the highest abundance of P. megacephala and abundance of other invertebrates was only 15% of natural levels. Pheidole megacephala is a serious potential threat to native biodiversity in monsoonal Australia. Successful eradication on a large scale is a realistic option and control methods are discussed, including chemicals and fire.

scholarly journals Revisiting the Scope of Collaboration in the Days of the Great Patriotic War: A Case-Study of the Smolensk Region

2018 ◽  
pp. 856-866
Author(s):  
Dmitriy E. Komarov ◽  
Keyword(s):  
Large Scale ◽  
Local Population ◽  
Controversial Issue ◽  
Potential Threat ◽  
Soviet Government ◽  
Scale Resistance ◽  
Great Patriotic War ◽  
Occupied Territories ◽  
Intense Debate

The article assesses the scope of collaboration in occupied Soviet territories in the days of the Great Patriotic War. This topic is a matter of intense debate in modern Russian scholarship. The most controversial issue is the extent to which Soviet citizens participated in events organized by invaders in occupied territories and the support which local population lent to occupation authorities. The article assesses potential threat of collaborationism in political, as well as economic terms. Having seized the richest and most economically developed regions of the country, the enemy could have significantly strengthened his military potential. National historiography has not yet integrated all data on stratification of local population in their stance toward invaders. It is an extremely difficult task to accomplish nationwide. As occupied territories were culturally, historically and socio-politically heterogeneous, it should be approached by studying republics and regions on a standalone basis. The case-study of the Smolensk region draws on archival materials to determine the share of Soviet citizens cooperating with occupation authorities within the framework of ‘administrative collaboration.’ It concludes that the number of Smolensk families whose members can be classified as ‘administrative collaborators,’ did not exceed 12%, whereas more than 9% of Smolensk families had members who took an active part in the struggle against invaders in the partisan detachments. Thus, the article demonstrates that two extreme irreconcilable phenomena in the occupied territories — collaborationism and partisans movement — were practically in balance. The absolute majority of Smolensk residents (almost 80%) did their utmost to avoid participation in both. Further developments in the Smolensk region proved that their ‘neutrality’ was conditional: the population remained loyal to the Soviet government and formed a social base for large-scale resistance to the occupation policy. Smolensk region became one of the centers of the partisan movement. To a certain extent, Smolensk data can be extrapolated to other western regions of the Russian non-black earth area.

scholarly journals INTEGRATED ASSESSMENT METHODOLOGY FOR LAND CONSOLIDATION PROJECTS: CASE STUDY PECINCI, SERBIA

2019 ◽  
Vol 1 (20) ◽  
Author(s):  
Goran Marinković ◽  
Jelena Lazić ◽  
Slobodan Morača ◽  
Ilija Grgić
Keyword(s):  
Agricultural Production ◽  
Integrated Assessment ◽  
Large Scale ◽  
Land Consolidation ◽  
Assessment Methodology ◽  
Southeast Europe ◽  
Strategic Issues ◽  
Land Redistribution ◽  
South Eastern Europe

Changes in the structure and fragmentation of land plots, arising from the process of privatization and restitution, as well as from the realization of large-scale infrastructural projects in Southeast Europe and similar, actualize problems in terms of intensive agricultural production, and aesthetic and functional spacing design. The need for initiating new projects regarding land consolidation cycles is increasing with the aim to solve spatial, environmental, and strategic issues in agriculture, as well as to provide appropriate conditions for the application of modern land treating methods. However, land consolidation projects are very complex, long-lasting and financially very demanding. To minimize risk and exclude the possibility of inadequate selection methods, this paper describes the methodology for integrated assessment, which allows decision making on the basis of two or more methods. Per integrated assessment methodology, this study includes several multi-criteria analysis methods, which do not exclude the possibility of integrating other methods. The results obtained in this study are not only beneficial to the South-Eastern Europe region, but also to all countries where land redistribution is expanding.

scholarly journals Thermofluid Modelling of Large-Scale Orchards for Optimal Design and Control of Active Frost Prevention Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 378
Author(s):  
Ercan Atam ◽  
Se-Woon Hong ◽  
Alessia Arteconi
Keyword(s):  
Optimal Design ◽  
Control Systems ◽  
Large Scale ◽  
Initial Conditions ◽  
Minimum Energy ◽  
Prunus Armeniaca ◽  
Thermal Dynamics ◽  
Heating Systems ◽  
And Control

Accurate modelling and simulation of temperature dynamics in large-scale orchards is important in many aspects, including: (i) for the calculation of minimum energy required to be used in optimal design of active frost prevention energy systems (fully renewable or partially renewable) to prevent freezing of fruit flowers, buds, or leaves; (ii) for testing frost prevention control systems before real-implementation which regulate active heating systems inside orchards targeted to prevent frost. To that end, in this study, first, a novel and sophisticated parametric computational thermofluid dynamics (CTFD) model for orchard air thermal dynamics for different orchard parameters (such as fruit type, climate, number of trees, their sizes, and distance between them) and boundary/initial conditions was developed and validated with field data from the literature. Next, the use of the developed parametric CTFD model was demonstrated through a case study to calculate the minimal thermal energy required to prevent frost under different frost levels in a test Prunus armeniaca orchard located in Malatya, Turkey, which is the world capital for dry apricot production.

Reactive tracers reveal hydraulic and control instabilities in full-scale activated sludge plant

2008 ◽  
Vol 57 (7) ◽  
pp. 1001-1007 ◽  
Author(s):  
D. Braun ◽  
W. Gujer
Keyword(s):  
Large Scale ◽  
Oxygen Sensor ◽  
Electrochemical Sensors ◽  
Aeration Tank ◽  
Control Loop ◽  
Reactive Tracers ◽  
And Control ◽  
Present Case Study ◽  
Aeration Control

The hydraulic characteristics of aeration tanks in WWTPs have a major impact on the degradation of pollutants, as well as on the control of the aeration. In particular in long reactors, which are not separated by baffles, hydraulic shortcuts or large scale recirculation can lead to a loss of performance. This work demonstrates that reactive tracers such as ammonium and oxygen can be used to investigate the hydraulics of aeration tanks in detail. With the use of electrochemical sensors it is possible to investigate effects in a broad range of time scales. In the present case study a slow oscillation of the aeration control loop was investigated. Large scale recirculation in the aeration tank and fast fluctuations of the ammonium concentrations close to the oxygen sensor were identified as the cause of these oscillations. Both, the recirculation as well as the fluctuation of the ammonium have a substantial influence on the performance of the aeration tank and the aeration control loop.

scholarly journals Power monitoring and control for large scale projects: SKA, a case study

2016 ◽  
Author(s):  
Domingos Barbosa ◽  
João Paulo Barraca ◽  
Dalmiro Maia ◽  
Bruno Carvalho ◽  
Jorge Vieira ◽  
...  
Keyword(s):  
Large Scale ◽  
Monitoring And Control ◽  
Power Monitoring ◽  
And Control

scholarly journals A decomposition algorithm of Petri net utilizing index function

Filomat ◽  
2020 ◽  
Vol 34 (15) ◽  
pp. 5085-5094
Author(s):  
Kai-Qing Zhou ◽  
Li-Ping Mo ◽  
Chang-Feng Chen ◽  
Wei Jiang
Keyword(s):  
Petri Net ◽  
Large Scale ◽  
Dynamic Properties ◽  
Decomposition Algorithm ◽  
State Explosion ◽  
Decomposition Approach ◽  
Index Function ◽  
Knowledge Based ◽  
And Control

Recently, it is difficult to simulate, analyze and control a real knowledge-based system using the correspondence Petri net (PN) when there exist many current states. To overcome the state explosion problem of PN, an efficient decomposition algorithm is presented to divide a large-scale PN into a series of corresponding sub-PNs by keeping the consistency of dynamic properties. In this novel decomposition approach, an index function is defined to judge the subnet needs to be decomposed or not. Furthermore, an exhaustive analysis on the consistency of related dynamic properties is also discussed between the original PN and the corresponding sub-PNs. Finally, a case study is carried out to illustrate the feasibility and validity of the proposed approach.

scholarly journals Into the thirteenth Month: A Case Study on the Outbreak Analytics and Modeling the spread of SARS-CoV-2 Infection in Pune City, India

2021 ◽  
Author(s):  
Joy Monteiro ◽  
Bhalchandra Pujari ◽  
Sarika Maitra Bhattacharrya ◽  
Anu Raghunathan ◽  
Ashwini Keskar ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Information Dissemination ◽  
Public Access ◽  
Accurate Information ◽  
Time Data ◽  
Outbreak Response ◽  
First Case ◽  
And Control

With more than 140 million people infected globally and 3 million deaths, the COVID 19 pandemic has left a lasting impact. A modern response to a pandemic of such proportions needs to focus on exploiting all available data to inform the response in real-time and allow evidence-based decision-making. The intermittent lockdowns in the last 13 months have created economic adversity to prevent anticipated large-scale mortality and relax the lockdowns have been an attempt at recovering and balancing economic needs and public health realities. This article is a comprehensive case study of the outbreak in the city limits of Pune, Maharashtra, India, to understand the evolution of the disease and transmission dynamics starting from the first case on March 9, 2020. A unique collaborative effort between the Pune Municipal Corporation (PMC), a government entity, and the Pune knowledge Cluster (PKC) allowed us to layout a context for outbreak response and intervention. We report here how access to granular data for a metropolitan city with pockets of very high-density populations will help analyze, in real-time, the dynamics of the pandemic and forecasts for better management and control of SARS-CoV-2. Outbreak data analytics resulted in a real-time data visualization dashboard for accurate information dissemination for public access on the epidemic's progress. As government agencies craft testing and vaccination policies and implement intervention strategies to mitigate a second wave, our case study underscores the criticality of data quality and analytics to decode community transmission of COVID-19.

scholarly journals Managing Recurrent Congestion of Subway Network in Peak Hours with Station Inflow Control

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Qingru Zou ◽  
Xiangming Yao ◽  
Peng Zhao ◽  
Fei Dou ◽  
Taoyuan Yang
Keyword(s):  
Large Scale ◽  
Practical Applications ◽  
C Programming Language ◽  
Passenger Flow ◽  
Assignment Model ◽  
C Programming ◽  
Subway System ◽  
And Control ◽  
Internal Relationship

Station inflow control (SIC) is an important and effective method for reducing recurrent congestion during peak hours in the Beijing, Shanghai, and Guangzhou subway systems. This work proposes a practical and efficient method for establishing a static SIC scheme in normal weekdays for large-scale subway networks. First, a traffic assignment model without capacity constraint is utilized to determine passenger flow distributions on the network. An internal relationship between station inflows and section flows is then constructed. Second, capacity bottlenecks are identified by considering the transport capacity of each section. Then, a feedback-based bottleneck elimination strategy is established to search target control stations and determine their control time and control strength. To validate the effectiveness of the proposed approach, a decision support system coded in the C# programming language was developed, and the Beijing subway was used as a case study. The results indicate that the proposed method and tool are capable of practical applications, and the generated SIC plan has better performance over the existing SIC plan. This study provides a practical and useful method for operation agencies to construct SIC schemes in the subway system.

scholarly journals Modelica-Based Modeling and Simulation of District Cooling Systems: A Case Study

2021 ◽  
Author(s):  
Kathryn Hinkelman ◽  
Jing Wang ◽  
Wangda Zuo ◽  
Antoine Gautier ◽  
Michael Wetter ◽  
...  
Keyword(s):  
Carbon Dioxide Emissions ◽  
Large Scale ◽  
Cooling System ◽  
Object Oriented ◽  
College Campus ◽  
Cooling Systems ◽  
Source Models ◽  
Electricity Costs ◽  
And Control

While equation-based object-oriented modeling language Modelica can evaluate practical energy improvements for district cooling systems, few have adapted Modelica for this type of large-scale thermo-fluid system. Further, to our best knowledge, district cooling modeling studies have yet to include hydraulics in piping network nor waterside economizers. These are critical details to include when looking to make energy and control improvements in many physical system installations. To fi?ll these gaps, this study applies newly developed open-source models from the Modelica Buildings library. For a real-world case study, we modeled and simulated a district cooling system at a college campus in Colorado, United States, with six buildings connected to a central chiller plant featuring a waterside economizer. Several energy saving strategies are pursued based on the validated model, including control setpoint optimization, equipment modification, and pump setpoint adjustments. Results indicate that optimizing the condenser water supply temperature setpoint can save 2.5% to 4.4% energy; the nonintegrated waterside economizer saves 6.4% energy while cutting down the chillers' run times by 201 days/year, reducing maintenance costs, and extending chiller life; and adjusting the condenser water pump flow settings can save 10.2% energy. Through a combinationof the studied measures, the campus can annually save 84.6 MWh of energy, 8.9% of electricity costs, and 58.0 metric tons of carbon dioxide emissions. Further, the numerical results of simulating districts from tens to hundreds of buildings are presented.

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