Studying the impact of depth of focus on 3D profile of negative photoresist material: a simulation approach

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.

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A Novel Design of Landing Gear Oleo Strut Damper Using MR Fluid for Aircraft and UAV’s

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.225.275 ◽

2012 ◽

Vol 225 ◽

pp. 275-280

Author(s):

Chandra B. Asthana ◽

Rama B. Bhat

Keyword(s):

Shock Absorber ◽

Fluid Viscosity ◽

Simulation Approach ◽

Body Frame ◽

Mr Fluid ◽

Orifice Area ◽

Aerial Vehicle ◽

Impact Kinetic Energy ◽

The Impact ◽

Novel Design

Most landing gears used in aircraft employ very efficient oleo-pneumatic dampers to absorb and dissipate the impact kinetic energy of the aircraft body frame. A single-acting shock absorber is most commonly used in the oleo strut that has a metering pin extending through the orifice, which can vary the orifice area upon compression and extension of the strut. This variation is adjusted by shaping the metering pin so that the strut load is fairly constant under dynamic loading. In this paper, it is proposed to further change the damping coefficient as a function of time in order to achieve a semi-active control of the aircraft vibrations during landing by using Magnetorheological (MR) fluid in the Oleo. With the metering pin designed for a nominal flight condition, further variation in the fluid viscosity would help achieve the optimal performance in off-nominal flight conditions. A simulation approach is employed to show the effect of different profiles for viscosity variation in the MR fluid. The utility of such a damper can be very well exploited to include different criteria such as the landing distance after touchdown. This type of system can be used also in Unmanned Aerial Vehicle (UAV) application where the focus of design may be to accomplish the task without the consideration of passenger comfort.

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The impact of nonresponse in different survey stages on the precision of prevalence estimates for multi-stage survey studies

BMC Research Notes ◽

10.1186/s13104-021-05840-0 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Ming Ma ◽

Sophie Rosenberg ◽

Alexander M. Kaizer

Keyword(s):

Survey Research ◽

State Level ◽

Simulation Approach ◽

Multi Stage ◽

Margin Of Error ◽

Prevalence Estimates ◽

Three Stages ◽

Nonresponse Rate ◽

The Mean ◽

The Impact

Abstract Objective While it is known that nonresponse might produce biased results and impair the precision of results in survey research studies, the pattern of the impact on the precision of estimates due to the nonresponse in different survey stages is historically overlooked. Having this type of information is essential when creating recruitment plans. This study proposes to examine and compare the effect of nonresponse in different stages on the precision of prevalence estimates in multi-stage survey studies. Based on data from a state level survey, a simulation approach was used to generate datasets with different nonresponse rates in three stages. The margin of error was then compared between the datasets with nonresponse at three different survey stages for 12 outcomes. Results At the same nonresponse rate, the mean margin of error was greater for the data with nonresponse at higher stages. Additionally, as the nonresponse rate increased, precision was more inflated within the data with higher stage nonresponse. This suggests that the effort used to recruit the primary sampling units is more crucial to improve the precision of estimates in multi-stage survey studies.

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Measuring Market Risk of Commercial Banks Implementing VaR with Historical Simulation Approach

10.47260/jafb/1144 ◽

2021 ◽

pp. 79-99

Author(s):

Minhaz-Ul Haq

Keyword(s):

Stock Prices ◽

Commercial Banks ◽

Value At Risk ◽

First Generation ◽

Market Risk ◽

Jel Classification ◽

Simulation Approach ◽

Share Prices ◽

Historical Simulation ◽

The Impact

This paper attempts to picture the impact of the market risk of ten commercial banks located in Bangladesh with the help of a non-parametric model known as the Historical Simulation Approach over the course of eight years. These banks' daily stock prices were used as inputs and analyzed in Microsoft Excel by means of Percentile and LN function. The study revealed market risk exposure as third, second-and first-generation banks from the least to the highest. It also pointed out the ups and downs of these banks' share prices in the selected period. Further analysis showed the portfolio VaR estimation for different time intervals. JEL classification numbers: G32. Keywords: Value-at-risk, Historical Simulation, Market Risk, Confidence Interval.

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