An Efficient Budget Allocation Approach for Quantifying the Impact of Input Uncertainty in Stochastic Simulation

2017 ◽  
Vol 27 (4) ◽  
pp. 1-23 ◽  
Author(s):  
Yuan Yi ◽  
Wei Xie
2012 ◽  
Vol 43 (1-2) ◽  
pp. 54-63 ◽  
Author(s):  
Baohong Lu ◽  
Huanghe Gu ◽  
Ziyin Xie ◽  
Jiufu Liu ◽  
Lejun Ma ◽  
...  

Stochastic simulation is widely applied for estimating the design flood of various hydrosystems. The design flood at a reservoir site should consider the impact of upstream reservoirs, along with any development of hydropower. This paper investigates and applies a stochastic simulation approach for determining the design flood of a complex cascade of reservoirs in the Longtan watershed, southern China. The magnitude of the design flood when the impact of the upstream reservoirs is considered is less than that without considering them. In particular, the stochastic simulation model takes into account both systematic and historical flood records. As the reliability of the frequency analysis increases with more representative samples, it is desirable to incorporate historical flood records, if available, into the stochastic simulation model. This study shows that the design values from the stochastic simulation method with historical flood records are higher than those without historical flood records. The paper demonstrates the advantages of adopting a stochastic flow simulation approach to address design-flood-related issues for a complex cascade reservoir system.


2021 ◽  
Vol 18 (3) ◽  
pp. 1-21
Author(s):  
Shoulu Hou ◽  
Wei Ni ◽  
Ming Wang ◽  
Xiulei Liu ◽  
Qiang Tong ◽  
...  

In 5G systems and beyond, traditional generic service models are no longer appropriate for highly customized and intelligent services. The process of reinventing service models involves allocating available resources, where the performance of service processes is determined by the activity node with the lowest service rate. This paper proposes a new bottleneck-aware resource allocation approach by formulating the resource allocation as a max-min problem. The approach can allocate resources proportional to the workload of each activity, which can guarantee that the service rates of activities within a process are equal or close-to-equal. Based on the business process simulator (i.e., BIMP) simulation results show that the approach is able to reduce the average cycle time and improve resource utilization, as compared to existing alternatives. The results also show that the approach can effectively mitigate the impact of bottleneck activity on the performance of service processes.


1998 ◽  
Vol 28 (5) ◽  
pp. 703-710 ◽  
Author(s):  
Erhard John Dobesberger

A stochastic simulation model was developed to derive a damage function for the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), and balsam fir, Abies balsamea (L.) Mill., herbivore interaction at the stand level for open-grown trees. Both aggregated and uniform models of attack pattern by late-instar larvae based on k of the negative binomial were evaluated to determine the impact of larval density and attack pattern on the loss in stemwood volume increment of young, thinned balsam fir stands in Newfoundland. Percentage loss in stemwood increment was a nonlinear, negative exponential function of initial larval density. Implementation of control measures to prevent 50% defoliation that is caused by about 14 larvae/branch tip would result in saving 24% of the annual stemwood increment after 1 year of defoliation and about 32% after 2 years of cumulative defoliation. Aggregation of spruce budworm larvae among trees within a forest stand results in less growth loss compared with a uniform pattern of attack. The nonlinear damage function may suggest tolerance and possibly compensatory growth after herbivory by low population levels of the spruce budworm.


2014 ◽  
Vol 11 (1) ◽  
pp. 1125-1167 ◽  
Author(s):  
P. Karimi ◽  
W. G. M. Bastiaanssen ◽  
A. Sood ◽  
J. Hoogeveen ◽  
L. Peiser ◽  
...  

Abstract. Water Accounting Plus (WA+) is a framework that summarizes complex hydrological processes and water management issues in river basins. The framework is designed to use satellite based measurements of land and water as input data. A concern associated with the use of satellite measurements is their accuracy. This study focuses on the impact of the error in remote sensing measurements on water accounting and information provided to policy makers. The Awash basin in the central rift valley in Ethiopia is used as a case study to explore the reliability of WA+ outputs, in the light of input data errors. The Monte Carlo technique was used for stochastic simulation of WA+ outputs over a period of three years. The results show that the stochastic mean of the majority of WA+ parameters and performance indicators are within 5% deviation from the original values. Stochastic simulation can be used as part of a standard procedure for WA+ water accounting because it provides the error bandwidth for every WA+ output, which is essential information for sound decision making. The majority of WA+ parameters and performance indicators have a Coefficient of Variation (CV) of less than 20% which implies that they are reliable. The results also indicate that the "utilized flow" and "basin closure fraction" (the degree to which available water in a basin is utilized) have a high margin of error and thus a low reliability. As such it is recommended that they are not used to formulate important policy decisions.


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