Modeling the interaction of birds and small fish in a coastal lagoon

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shashi Kant
Keyword(s):  
Dynamical System ◽  
Tropical Cyclones ◽  
Heat Waves ◽  
Coastal Lagoons ◽  
System Modeling ◽  
India Meteorological Department ◽  
Small Fish ◽  
Solution Stability ◽  
Chilika Lake ◽  
Proposed Model

Abstract Coastal lagoons are high value productive and important systems for different projects. For example, aquaculture, fisheries and tourism are few of them. The quality of coastal waters in the ecosystems of lagoons can be greatly influenced by the growth of unwanted elements, e.g., excessive fisheries, tourism, etc. In this paper, a mathematical model is proposed and analysed to study the general and simplified form of an ecosystem of Chilika Lake, India. Chilika Lake (19°28′N–19°54′N and 85°06′E–85°36′E) is the largest wintering ground for migrating water fowl found anywhere on the Indian sub-continent. These migratory birds utilize the Chilika Lake for feeding, resting and breeding. The interaction of birds and small fish in the Chilika Lake is considered to be Leslie–Gower Holling type II. Since big fish are being sourced as income for local fishermen and the population of big fish is highly variable, and hence birds and small fishes are mainly the two types of biomass considered for this study. It must be noted that, in this study, we have considered the case of Chilika lake theoretically only and no practical data is collected for this study, and the name of Chilika is used only for better ecological understanding. Therefore, this theoretical study maybe linked to any such ecosystem. Their interaction is found mathematically, a two-dimensional continuous-time dynamical system modeling a simple predator–prey food chain. The dynamical system is represented in the form of two nonlinear coupled ordinary differential equation (ODE) systems. The main mathematical results are given in terms of boundedness of solutions, existence of equilibria, local and global stability of the coexisting interior point. An ecosystem in Indian coastal lagoons may suffer immediate environmental perturbations, such as depressions, tropical cyclones, earthquakes, epidemics, etc. To model such situations, the ODE model is further extended to a stochastic model driven by L e ́ $\check{d}{e}$ vy noise. The stochastic analysis includes the existence of the unique global solution, stability in mean, and extinction of the population. The proposed model is numerically simulated with the help of an assumed set of parameters for the possible pictorial behavior of the theoretical model. The proposed model may be used for planning purposes by using the data on meteorological and weather shocks such as heavy rainfall, heat-waves, cold-waves, depressions, tropical cyclones, earthquakes, etc. from India Meteorological Department (IMD).

Warm Cores, Eyewall Slopes, and Intensities of Tropical Cyclones Simulated by a 7-km-Mesh Global Nonhydrostatic Model

2016 ◽  
Vol 73 (11) ◽  
pp. 4289-4309 ◽  
Author(s):  
Tomoki Ohno ◽  
Masaki Satoh ◽  
Yohei Yamada
Keyword(s):  
Tropical Cyclones ◽  
Inner Core ◽  
Grid Spacing ◽  
Satellite Measurements ◽  
Warm Core ◽  
Nonhydrostatic Model ◽  
Proposed Model ◽  
Tangential Wind ◽  
Balanced Model ◽  
Horizontal Grid

Abstract Based on the data of a 1-yr simulation by a global nonhydrostatic model with 7-km horizontal grid spacing, the relationships among warm-core structures, eyewall slopes, and the intensities of tropical cyclones (TCs) were investigated. The results showed that stronger TCs generally have warm-core maxima at higher levels as their intensities increase. It was also found that the height of a warm-core maximum ascends (descends) as the TC intensifies (decays). To clarify how the height and amplitude of warm-core maxima are related to TC intensity, the vortex structures of TCs were investigated. By gradually introducing simplifications of the thermal wind balance, it was established that warm-core structures can be reconstructed using only the tangential wind field within the inner-core region and the ambient temperature profile. A relationship between TC intensity and eyewall slope was investigated by introducing a parameter that characterizes the shape of eyewalls and can be evaluated from satellite measurements. The authors found that the eyewall slope becomes steeper (shallower) as the TC intensity increases (decreases). Based on a balanced model, the authors proposed a relationship between TC intensity and eyewall slope. The result of the proposed model is consistent with that of the analysis using the simulation data. Furthermore, for sufficiently strong TCs, the authors found that the height of the warm-core maximum increases as the slope becomes steeper, which is consistent with previous observational studies. These results suggest that eyewall slopes can be used to diagnose the intensities and structures of TCs.

Applications of the Impedance Method on Multiple Piezoelectric Actuators Driven Structures

2000 ◽  
Vol 123 (2) ◽  
pp. 262-268 ◽  
Author(s):  
C. C. Cheng ◽  
P. W. Wang
Keyword(s):  
System Modeling ◽  
Excitation Frequency ◽  
Vibration Response ◽  
Impedance Method ◽  
Dynamic Interactions ◽  
Active Structure ◽  
Impedance Model ◽  
Proposed Model ◽  
Host Structure ◽  
Arbitrary Location

An impedance-based system modeling technique has been developed to determine the output forces of multiple piezoelectric (PZT) patch actuators on an active structure to produce a known vibration response. In the analysis of the dynamic response of a structure driven by multiple PZT patches, the proposed model includes not only the dynamic interactions between the PZT patch and the host structure but also the impedance couplings among PZT patches. Therefore this approach can apply to a structure with multiple PZT actuators. Furthermore, the bending stiffness and the thickness of a PZT patch that are proved to be important as increases of excitation frequency are included in the proposed impedance model. Examples are given to demonstrate how to synthesize a known vibration response and how to suppress vibration response at an arbitrary location on structures using this technique.

scholarly journals Interpolative Boolean Networks

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-15
Author(s):  
Vladimir Dobrić ◽  
Pavle Milošević ◽  
Aleksandar Rakićević ◽  
Bratislav Petrović ◽  
Ana Poledica
Keyword(s):  
Boolean Algebra ◽  
System Modeling ◽  
Boolean Networks ◽  
Fuzzy Logics ◽  
Software Support ◽  
Modeling And Analysis ◽  
Proposed Model ◽  
Modeling Systems ◽  
Numerical Tools ◽  
Input Variables

Boolean networks are used for modeling and analysis of complex systems of interacting entities. Classical Boolean networks are binary and they are relevant for modeling systems with complex switch-like causal interactions. More descriptive power can be provided by the introduction of gradation in this model. If this is accomplished by using conventional fuzzy logics, the generalized model cannot secure the Boolean frame. Consequently, the validity of the model’s dynamics is not secured. The aim of this paper is to present the Boolean consistent generalization of Boolean networks, interpolative Boolean networks. The generalization is based on interpolative Boolean algebra, the [0,1]-valued realization of Boolean algebra. The proposed model is adaptive with respect to the nature of input variables and it offers greater descriptive power as compared with traditional models. For illustrative purposes, IBN is compared to the models based on existing real-valued approaches. Due to the complexity of the most systems to be analyzed and the characteristics of interpolative Boolean algebra, the software support is developed to provide graphical and numerical tools for complex system modeling and analysis.

scholarly journals Optimization of physical schemes in WRF model on cyclone simulations over Bay of Bengal using one-way ANOVA and Tukey’s test

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meenakshi Shenoy ◽  
P. V. S. Raju ◽  
Jagdish Prasad
Keyword(s):  
Boundary Layer ◽  
Tropical Cyclones ◽  
Planetary Boundary Layer ◽  
Bay Of Bengal ◽  
Wrf Model ◽  
India Meteorological Department ◽  
Cloud Microphysics ◽  
Optimal Combination ◽  
Cumulus Convection ◽  
Elimination Method

AbstractEvaluation of appropriate physics parameterization schemes for the Weather Research and Forecasting (WRF) model is vital for accurately forecasting tropical cyclones. Three cyclones Nargis, Titli and Fani have been chosen to investigate the combination of five cloud microphysics (MP), three cumulus convection (CC), and two planetary boundary layer (PBL) schemes of the WRF model (ver. 4.0) with ARW core with respect to track and intensity to determine an optimal combination of these physical schemes. The initial and boundary conditions for sensitivity experiments are drawn from the National Centers for Environmental Prediction (NCEP) global forecasting system (GFS) data. Simulated track and intensity of three cyclonic cases are compared with the India Meteorological Department (IMD) observations. One-way analysis of variance (ANOVA) is applied to check the significance of the data obtained from the model. Further, Tukey’s test is applied for post-hoc analysis in order to identify the cluster of treatments close to IMD observations for all three cyclones. Results are obtained through the statistical analysis; average root means square error (RMSE) of intensity throughout the cyclone period and time error at landfall with the step-by-step elimination method. Through the elimination method, the optimal scheme combination is obtained. The YSU planetary boundary layer with Kain–Fritsch cumulus convection and Ferrier microphysics scheme combination is identified as an optimal combination in this study for the forecasting of tropical cyclones over the Bay of Bengal.

scholarly journals A Suspension Footbridge Model under Crowd-Induced Lateral Excitation

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Lijun Ouyang ◽  
Bin Ding ◽  
Tingting Li ◽  
Bin Zhen
Keyword(s):  
Structural Characteristics ◽  
Random Phase ◽  
Suspension Bridge ◽  
Lateral Force ◽  
Solution Stability ◽  
Step Frequency ◽  
Plane Model ◽  
Worst Case ◽  
Proposed Model ◽  
Pendulum Model

In this paper, a plane pendulum model is proposed to investigate the lateral vibration of a suspension bridge under crowd excitation. The plane model consists of two strings and a rigid body, which represent cables and the bridge deck, respectively. The lateral force induced by crowd is expressed as a cosine function with random phase. Comparing with other existing pedestrian-footbridge interaction models, the proposed model has two features: one is that the structural characteristics of the suspension bridge are taken into account. The other is that the expression of the lateral force induced by crowd has a unified form for different lateral bridge amplitudes. By numerically analyzing the solution stability of the plane model, we exhibit the whole changing process how a suspension bridge increases its lateral amplitude from small to large. It is shown that the worst case occurs when the lateral natural frequency of the bridge is half the lateral step frequency of the pedestrians. Based on the analysis results, the plane pendulum model can be easily used to explain why the central span of the London Millennium Bridge has large lateral oscillations at about 0.48 Hz.

Human System Modeling Technique for Semiconductor Assembly and Test

2015 ◽  
Vol 761 ◽  
pp. 624-628
Author(s):  
R. Abdullah ◽  
Md Nizam Abd Rahman ◽  
Siti Nurhaida Khalil
Keyword(s):  
System Dynamics ◽  
Manufacturing System ◽  
System Modeling ◽  
Modeling Technique ◽  
Manufacturing Companies ◽  
Human System ◽  
Manufacturing Operations ◽  
Proposed Model ◽  
And Performance

Global competitions are putting pressure on the manufacturing companies to produce products cheaper and faster. Thus, manufacturing operations are urgently exploring methods to reduce cost through improved efficiency in managing the resources. In recent years, there has been growing interest to study human system due to the lack of focus as compared to other resources such as equipment and material. This paper presents the overview and evaluation of the various human issues affecting manufacturing system dynamics and performance. Furthermore, the gap in the current models will be discussed before presenting the development of a proposed model to study human system in semiconductor assembly and test.

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