On semigroup formulations of unbounded observations and control action for distributed systems

2005 ◽  
pp. 183-193 ◽  
Author(s):  
Ruth F. Curtain
Keyword(s):  
Distributed Systems ◽  
Control Action ◽  
And Control

Modelling global computations with Klaim

2008 ◽  
Vol 366 (1881) ◽  
pp. 3737-3745 ◽  
Author(s):  
Rocco De Nicola ◽  
Michele Loreti
Keyword(s):  
Distributed Systems ◽  
Formal Semantics ◽  
Wide Area ◽  
Wide Area Networks ◽  
Qualitative And Quantitative ◽  
Global Computing ◽  
New Models ◽  
And Control ◽  
Tuple Spaces ◽  
Coordination And Control

A new area of research, known as Global Computing, is by now well established. It aims at defining new models of computation based on code and data mobility over wide-area networks with highly dynamic topologies, and at providing infrastructures to support coordination and control of components originating from different, possibly untrusted, fault-prone, malicious or selfish sources. In this paper, we present our contribution to the field of Global Computing that is centred on Kernel Language for Agents Interaction and Mobility ( Klaim ). Klaim is an experimental language specifically designed to programme distributed systems consisting of several mobile components that interact through multiple distributed tuple spaces. We present some of the key notions of the language and discuss how its formal semantics can be exploited to reason about qualitative and quantitative aspects of the specified systems.

scholarly journals ДОСЯГНЕННЯ ЕФЕКТИВНОГО РОЗПОДІЛЕНОГО ПЛАНУВАННЯ ЗА ДОПОМОГОЮ ЧЕРГ ПОВІДОМЛЕНЬ У ХМАРІ ДЛЯ БАГАТОЗАДАЧНИХ ОБЧИСЛЕНЬ ТА ВИСОКОПРОДУКТИВНИХ ОБЧИСЛЕНЬ

2020 ◽  
Author(s):  
Старовойтенко Олексій Володимирович
Keyword(s):  
Distributed Systems ◽  
System Performance ◽  
State Of The Art ◽  
Computation Time ◽  
Cloud Services ◽  
Distributed Scheduling ◽  
Message Processing ◽  
Computational Problem ◽  
Control Units ◽  
And Control

Due to the growth of data and the number of computational tasks, it is necessary to ensure the required level of system performance. Performance can be achieved by scaling the system horizontally / vertically, but even increasing the amount of computing resources does not solve all the problems. For example, a complex computational problem should be decomposed into smaller subtasks, the computation time of which is much shorter. However, the number of such tasks may be constantly increasing, due to which the processing on the services is delayed or even certain messages will not be processed. In many cases, message processing should be coordinated, for example, message A should be processed only after messages B and C. Given the problems of processing a large number of subtasks, we aim in this work - to design a mechanism for effective distributed scheduling through message queues. As services we will choose cloud services Amazon Webservices such as Amazon EC2, SQS and DynamoDB. Our FlexQueue solution can compete with state-of-the-art systems such as Sparrow and MATRIX. Distributed systems are quite complex and require complex algorithms and control units, so the solution of this problem requires detailed research.

scholarly journals Long-term trends and drivers of aerosol pH in eastern China

2021 ◽  
Author(s):  
Min Zhou ◽  
Guangjie Zheng ◽  
Hongli Wang ◽  
Liping Qiao ◽  
Shuhui Zhu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Prevention And Control ◽  
Action Plan ◽  
Health Effect ◽  
Eastern China ◽  
Pollution Prevention ◽  
Control Action ◽  
Haze Pollution ◽  
Pollution Prevention And Control ◽  
And Control

Abstract. Aerosol acidity plays a key role in regulating the chemistry and toxicity of atmospheric aerosol particles. The trend of aerosol pH and its drivers are crucial in understanding the multiphase formation pathways of aerosols. Here, we reported the first trend analysis of aerosol pH from 2011 to 2019 in eastern China. The implementation of the Air Pollution Prevention and Control Action Plan leads to −35.8 %, −37.6 %, −9.6 %, −81.0 % and 1.2 % changes of PM2.5, SO42−, NHx, NVCs and NO3− in YRD during this period. Different from the fast changes of aerosol compositions due to the implementation of the Air Pollution Prevention and Control Action Plan, aerosol pH shows a moderate change of −0.24 unit over the 9 years. Besides the multiphase buffer effect, the opposite effects of SO42− and non-volatile cations changes play key roles in determining the moderate pH trend, contributing to a change of +0.38 and −0.35 unit, respectively. Seasonal variations in aerosol pH were mainly driven by the temperature, while the diurnal variations were driven by both temperature and relative humidity. In the future, SO2, NOx and NH3 emissions are expected to be further reduced by 86.9 %, 74.9 % and 41.7 % in 2050 according to the best health effect pollution control scenario (SSP1-26-BHE). The corresponding aerosol pH in eastern China is estimated to increase by ~0.9, resulting in 8 % more NO3− and 35 % less NH4+ partitioning/formation in the aerosol phase, which suggests a largely reduced benefit of NH3 and NOx emission control in mitigating haze pollution in eastern China.

Rough mereological foundations for design, analysis, synthesis, and control in distributed systems

1998 ◽  
Vol 104 (1-2) ◽  
pp. 129-156 ◽  
Author(s):  
Andrzej Skowron ◽  
Lech Polkowski
Keyword(s):  
Distributed Systems ◽  
Design Analysis ◽  
And Control
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