Simulation Modeling of the Algal–Fly Components of a Thermal Ecosystem: Effects of Spatial Heterogeneity, Time Delays, and Model Condensation

Author(s):  
RICHARD G. WIEGERT
Author(s):  
Linda Sicko-Goad

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.


2020 ◽  
Vol 17 (5) ◽  
pp. 34-47
Author(s):  
V. M. Polyakov ◽  
Z. S. Agalarov

The article offers a method for assessing the environmental risk in the territories adjacent to the planning zone of emergency protection measures around the NPP. The method is based on simulation modeling of territory pollution, which is formed at the late stage of a radiation accident and zoning of territories by risk, taking into account the characteristics of the population’s life in a potentially dangerous territory. A vector criterion of environmental risk is proposed that allows zoning these territories according to the degree of danger to the population.


2020 ◽  
Vol 17 (1) ◽  
pp. 58-67
Author(s):  
N. A. Kabanova ◽  
I. K. Alekseeva

The article is devoted to the assessment of potential investment risks of the pharmaceutical company “R-Pharm” JSC with the aim of identifying the highest priority risks and developing methods for minimizing them. The relevance of the study is determined by the fact that the pharmaceutical business is characterized by a high degree of social orientation and annually invests $ 140 billion in the development of production and research, which determines the need for a risk-based approach to ensure the return on investment. The subject of this article is the investment risks of pharmaceutical companies, and the subject of research is the domestic pharmaceutical company “R-Pharm”. In order to assess the potential investment risks of “R-Pharm” JSC, the authors used elements of simulation modeling and system analysis. The proposed methods to minimize key investment risks are aimed at improving the efficiency of investment activities and is recommended as an element of the strategic planning of the company.


Author(s):  
Fransiskus Lauson Matondang ◽  
Rosnani Ginting

PT XYZ sering mengalami keterlambatan waktu karena dalam setiap keterlambatan yang dilakukan selalu ada penalty yang diberikan kepada perusahaan dan hal ini mengakibatkan tambahan biaya , oleh karena itu hal ini harus dihindari dengan membuat penjadwalan yang efisien, dalam hal ini dilakukanlah perbaikan dengan meminimisasi waktu penyelesaian maksimum Cmax pada mesin paralel yang berpola aliran flowshop (dan tidak boleh dilakukan interupsi yang dilakukan pada pekerjaan yang sedang diproses, untuk melakukan pekerjaan lainnya, satu lintasan hanya memproduksi satu produk dan hanya satu produk juga yang dikerjakan secara langsung. Waktu penyelesaian yang berbeda dari setiap mesin dengan pengerjaannya juga adalah masalah yang dihadapi untuk menjadikan mesin mesin ini sesuai menjadi satu penjadwalan yang terintegrasi dengan metode integer programming yang membuat penjadwalan dengan konsep riset operasi dengan metode pendekatan 0-1 utuk menjadi lebih efisien lagi , dihasilkan minimisasi keterlambatan total penyelesaian order dengan 42,28 menit lebih baik dari sebelumnya.   PT XYZ often experiences time delays because in every delay made there is always a penalty given to the company and this results in additional costs, therefore this must be avoided by making efficient scheduling, in this case repairs are carried out by minimizing the maximum completion time of Cmax on parallel machines that are patterned with flowshop flow (and no interruptions should be carried out on the work being processed, to do other work, one track only produces one product and only one product is directly worked. Different completion times of each machine with the workmanship is also the problem faced to make this machine suitable to be one scheduling integrated with integer programming methods that makes scheduling with the operational research concept with the 0-1 approach method to be more efficient, resulting in minimization of the delay in the total settlement of orders with 42.28 minutes was better than before.


2012 ◽  
Vol 449 ◽  
pp. 27-40 ◽  
Author(s):  
J Näslund ◽  
GS Samuelsson ◽  
JS Gunnarsson ◽  
FJA Nascimento ◽  
HC Nilsson ◽  
...  

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