Search results for: dynamical hunting
310 Damping and Stability Evaluation for the Dynamical Hunting Motion of the Bullet Train Wheel Axle Equipped with Cylindrical Wheel Treads
Authors: Barenten Suciu
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Classical matrix calculus and Routh-Hurwitz stability conditions, applied to the snake-like motion of the conical wheel axle, lead to the conclusion that the hunting mode is inherently unstable, and its natural frequency is a complex number. In order to analytically solve such a complicated vibration model, either the inertia terms were neglected, in the model designated as geometrical, or restrictions on the creep coefficients and yawing diameter were imposed, in the so-called dynamical model. Here, an alternative solution is proposed to solve the hunting mode, based on the observation that the bullet train wheel axle is equipped with cylindrical wheels. One argues that for such wheel treads, the geometrical hunting is irrelevant, since its natural frequency becomes nil, but the dynamical hunting is significant since its natural frequency reduces to a real number. Moreover, one illustrates that the geometrical simplification of the wheel causes the stabilization of the hunting mode, since the characteristic quartic equation, derived for conical wheels, reduces to a quadratic equation of positive coefficients, for cylindrical wheels. Quite simple analytical expressions for the damping ratio and natural frequency are obtained, without applying restrictions into the model of contact. Graphs of the time-depending hunting lateral perturbation, including the maximal and inflexion points, are presented both for the critically-damped and the over-damped wheel axles.Keywords: bullet train, creep, cylindrical wheels, damping, dynamical hunting, stability, vibration analysis
Procedia PDF Downloads 153309 Dynamical Systems and Fibonacci Numbers
Authors: Vandana N. Purav
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The Dynamical systems concept is a mathematical formalization for any fixed rule that describes the time dependence of a points position in its ambient space. e.g. pendulum of a clock, the number of fish each spring in a lake, the number of rabbits spring in an enclosure, etc. The Dynamical system theory used to describe the complex nature that is dynamical systems with differential equations called continuous dynamical system or dynamical system with difference equations called discrete dynamical system. The concept of dynamical system has its origin in Newtonian mechanics.Keywords: dynamical systems, Fibonacci numbers, Newtonian mechanics, discrete dynamical system
Procedia PDF Downloads 492308 The Prevailing Practice of Night Hunting in Central Bhutan: Traditional Practice of Courtship as a Sexual Coercion to Women
Authors: Ugyen Phuntsho
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A popular and entrenched custom as a form of courtship has been practicing in Bhutan from long time back. This custom is widely being practiced in the villages of eastern and central Bhutan. This long-practiced custom is known by different terms in Bhutan, but it is popularly known to the foreigners as ‘night hunting’. This unique form of courtship custom involves the boy visiting the girl’s house stealthily under the cover of darkness without any pre-appointment. It is still perceived as a serving norms of courtship in the villages in central Bhutan. For many years this practice of night hunting has been in the spotlight of debate as a harmless culture but as sexual violence against women. However, this study examined the changing perception on the night hunting as a form of courtship custom or sexual coercion to women by employing the in-depth interview with 42 participants (21 females and 9 males from 3 different villages, 5 females and 7 males from urban areas) in central Bhutan. Moreover, the study investigated the gender inequality linked with the practice of night hunting in the rural areas of central Bhutan. The study revealed the changing perception on night hunting as more of sexual coercion taking place during night hunting than merely tolerating it as traditional form of practice of courtship. The finding of this study revealed unlike the past; this practice serves minimal social purpose in the society as the social changes with the development of socioeconomic of the people. However, the practice of night hunting is still prevalent at the villages, and it is known that the social power, single and widow women, valuing of village endogamy practices and the popular notion of pride of promiscuous amongst the men have attributed in sexual coercion and in ultimate victimization of the women. Furthermore, the study revealed the gender inequality linked with night hunting thus significantly increasing the vulnerability of rural women to other forms of violence in the society.Keywords: courtship, custom, men, night hunting, practice, sexual coercion, women, violence
Procedia PDF Downloads 246307 Case Study on Socio-Economic Impacts of Sustainable Trophy Hunting Programme on Local Community of Sassi-Haramosh Conservancy, Gilgit District, Pakistan
Authors: Hassan Abbas, Rehmat Ali, Muhammad Akbar
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This study has been conducted in Sassi-Haramosh conservancy District Gilgit, Gilgit-Baltistan of Pakistan, under the Conservation Leadership Programme of Fauna and Flora International. The main objectives of the study were to assess the socio-economic impact of community-based conservation in Sassi-Haramosh conservancy and identify effects of trophy hunting on the conservation of wildlife in the area. The first trophy hunting program of Astor Markhor was held in year February 21, 2015, and the second on February 21, 2016. The community received a share of 49200 USD and 52400 USD from the first and second hunting, and the total earning was 101600 USD which are Rs. 10,871,200 in Pak Rs. The amounts from the trophy hunting are being managed by the Wildlife Conservation and Social Development Organization (WCSDO) Sassi. The village-based organization WCSDO is spending 50% of the trophy hunting amount in the protection of wildlife, its habitat and other natural resources, 30% in developmental sectors of the village and 20% of the amount in the office expenses. Several developmental projects, like construction of 300 KVA hydropower stations, purchase of 8 acres of land for agriculture, potable water supply project, construction of treks, and other social welfare activities have been carried in the village utilizing the trophy hunting grant. These developmental activities have uplifted the socio-economic conditions of the conservancy. Furthermore, trophy hunting program has positive impacts on the wildlife in the area, as the population of Markhor and Ibex has been increased, results in increasing number of other carnivores in the area. The WCSDO has banned any illegal activities in the habitat of wildlife and grazing of livestock in the core habitats. The program raised the level of awareness in communities and reduced poaching, illegal hunting, cutting of shrubs and extraction of Artemisia species from the pastures.Keywords: Markhor, trophy hunting, Sassi-Haramosh, Gilgit
Procedia PDF Downloads 257306 First Report of Asiatic Black Bear: Evidence of Illegal Hunting and Trading from Manglawar Mountain, Swat, Pakistan
Authors: Waheed Akhtar
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Bears in Asia facing multiple threats and challenges such as hunting, illegal trading, habitat loss, and human conflicts. According to IUCN Red List, the Asiatic black bear (Ursus thibetanus) is listed as Vulnerable since 1990, population declining by 49% during the last 30 years. The present study was conducted in Manglawar (DwaSaro Mountain) from April-August 2021, to collect all the information on Asiatic black bear observation, illegal hunting, and cub poaching. According to the response of the local community, very intensive illegal hunting and cub poaching were observed. Hunters usually installed many traps in the routes of black bears and when they move in the winter season the cubs get trapped and they collect them and kept in a specialized wooden box that is mainly helpful for further transportation. These cubs are then brought to the concerned Market where they sell them to many dealers. One of the potential observers of the illegal trading responds towards the Market price of the cubs, “The average price of the black bear cub is ranging from 45000-50000 Pakistani Rupees”. Apart from cubs' poaching, the black bear is also hunted for its skin, claws, and teeth.Keywords: first report, illegal hunting, cub poaching, parts trading, Ursus thibetanus
Procedia PDF Downloads 63305 Modeling and Controlling Nonlinear Dynamical Effects in Non-Contact Superconducting and Diamagnetic Suspensions
Authors: Sergey Kuznetsov, Yuri Urman
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We present an approach to investigate non-linear dynamical effects occurring in the noncontact superconducting and diamagnetic suspensions, when levitated body has finite size. This approach is based on the calculation of interaction energy between spherical finite size superconducting or diamagnetic body with external magnetic field. Effects of small deviations from spherical shape may be also taken into account by introducing small corrections to the energy. This model allows investigating dynamical effects important for practical applications, such as nonlinear resonances, change of vibration plane, coupling of rotational and translational motions etc. We also show how the geometry of suspension affects various dynamical effects and how an inverse problem may be formulated to enforce or diminish various dynamical effects.Keywords: levitation, non-linear dynamics, superconducting, diamagnetic stability
Procedia PDF Downloads 410304 Model-Free Distributed Control of Dynamical Systems
Authors: Javad Khazaei, Rick Blum
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Distributed control is an efficient and flexible approach for coordination of multi-agent systems. One of the main challenges in designing a distributed controller is identifying the governing dynamics of the dynamical systems. Data-driven system identification is currently undergoing a revolution. With the availability of high-fidelity measurements and historical data, model-free identification of dynamical systems can facilitate the control design without tedious modeling of high-dimensional and/or nonlinear systems. This paper develops a distributed control design using consensus theory for linear and nonlinear dynamical systems using sparse identification of system dynamics. Compared with existing consensus designs that heavily rely on knowing the detailed system dynamics, the proposed model-free design can accurately capture the dynamics of the system with available measurements and input data and provide guaranteed performance in consensus and tracking problems. Heterogeneous damped oscillators are chosen as examples of dynamical system for validation purposes.Keywords: consensus tracking, distributed control, model-free control, sparse identification of dynamical systems
Procedia PDF Downloads 265303 Clarifications on the Damping Mechanism Related to the Hunting Motion of the Wheel Axle of a High-Speed Railway Vehicle
Authors: Barenten Suciu
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In order to explain the damping mechanism, related to the hunting motion of the wheel axle of a high-speed railway vehicle, a generalized dynamic model is proposed. Based on such model, analytic expressions for the damping coefficient and damped natural frequency are derived, without imposing restrictions on the ratio between the lateral and vertical creep coefficients. Influence of the travelling speed, wheel conicity, dimensionless mass of the wheel axle, ratio of the creep coefficients, ratio of the track span to the yawing diameter, etc. on the damping coefficient and damped natural frequency, is clarified.Keywords: high-speed railway vehicle, hunting motion, wheel axle, damping, creep, vibration model, analysis.
Procedia PDF Downloads 290302 Pathology of the Partridge Gambra Alectoris barbara in a Semi-Captive Breeding in the Algiers Sahel
Authors: H. Saadi-Idouhar, A. Smai, S. Zenia, F. Haddadj, A. Saadi, M. Aissi, S. Doumandji
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In Algeria, the Partridge gambra is a highly sought-after game species and is appreciated for its meat. Game birds are of interest because they play an important role for hunting federations and for the economy of a country. The breeding of indigenous breeds is necessary because it is of great economic interest. However, gambra breeding in the hunting centre of Zeralda (northern west of Algiers) is not easy, several diseases affecting Perdreaux and reproducing adults have been noted. Most of the diseases observed are parasitic in origin. This study is conducted during the 2010 breeding season. It is based on the autopsy of cadavers collected at the hunting centre and parasitic coprology. Indeed, the flotation enrichment method has identified several parasites such as Eimeria spp., Capillaria spp., and Ascaridia spp. Autopsied corpses show the importance of two major diseases, syngamosis caused to Syngamus trachea and histomonosis caused to Histomonas meleagridis.Keywords: partridge, livestock, eggs, affections pathology
Procedia PDF Downloads 180301 Projective Lag Synchronization in Drive-Response Dynamical Networks via Hybrid Feedback Control
Authors: Mohd Salmi Md Noorani, Ghada Al-Mahbashi, Sakhinah Abu Bakar
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This paper investigates projective lag synchronization (PLS) behavior in drive response dynamical networks (DRDNs) model with identical nodes. A hybrid feedback control method is designed to achieve the PLS with mismatch and without mismatch terms. The stability of the error dynamics is proven theoretically using the Lyapunov stability theory. Finally, analytical results show that the states of the dynamical network with non-delayed coupling can be asymptotically synchronized onto a desired scaling factor under the designed controller. Moreover, the numerical simulations results demonstrate the validity of the proposed method.Keywords: drive-response dynamical network, projective lag synchronization, hybrid feedback control, stability theory
Procedia PDF Downloads 391300 On the Topological Entropy of Nonlinear Dynamical Systems
Authors: Graziano Chesi
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The topological entropy plays a key role in linear dynamical systems, allowing one to establish the existence of stabilizing feedback controllers for linear systems in the presence of communications constraints. This paper addresses the determination of a robust value of the topological entropy in nonlinear dynamical systems, specifically the largest value of the topological entropy over all linearized models in a region of interest of the state space. It is shown that a sufficient condition for establishing upper bounds of the sought robust value of the topological entropy can be given in terms of a semidefinite program (SDP), which belongs to the class of convex optimization problems.Keywords: non-linear system, communication constraint, topological entropy
Procedia PDF Downloads 320299 Investigation on the Bogie Pseudo-Hunting Motion of a Reduced-Scale Model Railway Vehicle Running on Double-Curved Rails
Authors: Barenten Suciu, Ryoichi Kinoshita
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In this paper, an experimental and theoretical study on the bogie pseudo-hunting motion of a reduced-scale model railway vehicle, running on double-curved rails, is presented. Since the actual bogie hunting motion, occurring for real railway vehicles running on straight rails at high travelling speeds, cannot be obtained in laboratory conditions, due to the speed and wavelength limitations, a pseudo- hunting motion was induced by employing double-curved rails. Firstly, the test rig and the experimental procedure are described. Then, a geometrical model of the double-curved rails is presented. Based on such model, the variation of the carriage rotation angle relative to the bogies and the working conditions of the yaw damper are clarified. Vibration spectra recorded during vehicle travelling, on straight and double-curved rails, are presented and interpreted based on a simple vibration model of the railway vehicle. Ride comfort of the vehicle is evaluated according to the ISO 2631 standard, and also by using some particular frequency weightings, which account for the discomfort perceived during the reading and writing activities. Results obtained in this work are useful for the adequate design of the yaw dampers, which are used to attenuate the lateral vibration of the train car bodies.Keywords: double-curved rail, octave analysis, vibration model, ride comfort, railway vehicle
Procedia PDF Downloads 316298 Investigation on Performance of Change Point Algorithm in Time Series Dynamical Regimes and Effect of Data Characteristics
Authors: Farhad Asadi, Mohammad Javad Mollakazemi
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In this paper, Bayesian online inference in models of data series are constructed by change-points algorithm, which separated the observed time series into independent series and study the change and variation of the regime of the data with related statistical characteristics. variation of statistical characteristics of time series data often represent separated phenomena in the some dynamical system, like a change in state of brain dynamical reflected in EEG signal data measurement or a change in important regime of data in many dynamical system. In this paper, prediction algorithm for studying change point location in some time series data is simulated. It is verified that pattern of proposed distribution of data has important factor on simpler and smother fluctuation of hazard rate parameter and also for better identification of change point locations. Finally, the conditions of how the time series distribution effect on factors in this approach are explained and validated with different time series databases for some dynamical system.Keywords: time series, fluctuation in statistical characteristics, optimal learning, change-point algorithm
Procedia PDF Downloads 426297 Evaluation of Illegal Hunting of Red Deer and Conservation Policy of Department of Environment in Iran
Authors: Tahere Fazilat
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Caspian red deer or maral (Cervus elaphus maral) is the largest type of deer in iran. Maral in the past has lived in the north forests of Iran from the Caspian sea coast, Alborz mountains chain and oak forest of Zagros margin from the Azarbaijan up to fars province. However, the generation of them was completely destroyed in the north west and west of Iran. According to reports about 50 years and out of reach of humans. In the present studies, data were collected from 2004 to 2014 in the Mazandaran state Hyrcanian forest by means of guard of environment and justiciary office of department of environment of Mazandaran in this process the all arrested illegal hunting of red deer and the population census, estimation and the correlation of these data was assayed. We provide a first evaluation of how suitable these methods are by comparing the results with population estimates obtained using cohort analysis, and by analyzing the within-season variation in number of seen deer. The data gave us the future of red deer in northern forest of Iran and the results of policy of department of environment in Iran in red deer conservation.Keywords: illegal hunting, red deer, census, concervation
Procedia PDF Downloads 552296 X-Ray Dynamical Diffraction 'Third Order Nonlinear Renninger Effect'
Authors: Minas Balyan
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Nowadays X-ray nonlinear diffraction and nonlinear effects are investigated due to the presence of the third generation synchrotron sources and XFELs. X-ray third order nonlinear dynamical diffraction is considered as well. Using the nonlinear model of the usual visible light optics the third-order nonlinear Takagi’s equations for monochromatic waves and the third-order nonlinear time-dependent dynamical diffraction equations for X-ray pulses are obtained by the author in previous papers. The obtained equations show, that even if the Fourier-coefficients of the linear and the third order nonlinear susceptibilities are zero (forbidden reflection), the dynamical diffraction in the nonlinear case is related to the presence in the nonlinear equations the terms proportional to the zero order and the second order nonzero Fourier coefficients of the third order nonlinear susceptibility. Thus, in the third order nonlinear Bragg diffraction case a nonlinear analogue of the well-known Renninger effect takes place. In this work, the 'third order nonlinear Renninger effect' is considered theoretically.Keywords: Bragg diffraction, nonlinear Takagi’s equations, nonlinear Renninger effect, third order nonlinearity
Procedia PDF Downloads 385295 Time-Evolving Wave Packet in Phase Space
Authors: Mitsuyoshi Tomiya, Kentaro Kawamura, Shoichi Sakamoto
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In chaotic billiard systems, scar-like localization has been found on time-evolving wave packet. We may call it the “dynamical scar” to separate it to the original scar in stationary states. It also comes out along the vicinity of classical unstable periodic orbits, when the wave packets are launched along the orbits, against the hypothesis that the waves become homogenous all around the billiard. Then time-evolving wave packets are investigated numerically in phase space. The Wigner function is adopted to detect the wave packets in phase space. The 2-dimensional Poincaré sections of the 4-dimensional phase space are introduced to clarify the dynamical behavior of the wave packets. The Poincaré sections of the coordinate (x or y) and the momentum (Px or Py) can visualize the dynamical behavior of the wave packets, including the behavior in the momentum degree also. For example, in “dynamical scar” states, a bit larger momentum component comes first, and then the a bit smaller and smaller components follow next. The sections made in the momentum space (Px or Py) elucidates specific trajectories that have larger contribution to the “dynamical scar” states. It is the fixed point observation of the momentum degrees at a specific fixed point(x0, y0) in the phase space. The accumulation are also calculated to search the “dynamical scar” in the Poincare sections. It is found the scars as bright spots in momentum degrees of the phase space.Keywords: chaotic billiard, Poincaré section, scar, wave packet
Procedia PDF Downloads 452294 Dynamical Heterogeneity and Aging in Turbulence with a Nambu-Goldstone Mode
Authors: Fahrudin Nugroho, Halim Hamadi, Yusril Yusuf, Pekik Nurwantoro, Ari Setiawan, Yoshiki Hidaka
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We investigate the Nikolaevskiy equation numerically using exponential time differencing method and pseudo-spectral method. This equation develops a long-wavelength modulation that behaves as a Nambu–Goldstone mode, and short-wavelength instability and exhibit turbulence. Using the autocorrelation analysis, the statistical properties of the turbulence governed by the equation are investigated. The autocorrelation then has been fitted with The Kohlrausch– Williams–Watts (KWW) expression. By varying the control parameter, we show a transition from compressed to stretched exponential for the auto-correlation function of Nikolaevskiy turbulence. The compressed exponential is an indicator of the existence of dynamical heterogeneity while the stretched indicates aging process. Thereby, we revealed the existence of dynamical heterogeneity and aging in the turbulence governed by Nikolaevskiy equation.Keywords: compressed exponential, dynamical heterogeneity, Nikolaevskiy equation, stretched exponential, turbulence
Procedia PDF Downloads 436293 Quantum Localization of Vibrational Mirror in Cavity Optomechanics
Authors: Madiha Tariq, Hena Rabbani
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Recently, cavity-optomechanics becomes an extensive research field that has manipulated the mechanical effects of light for coupling of the optical field with other physical objects specifically with regards to dynamical localization. We investigate the dynamical localization (both in momentum and position space) for a vibrational mirror in a Fabry-Pérot cavity driven by a single mode optical field and a transverse probe field. The weak probe field phenomenon results in classical chaos in phase space and spatio temporal dynamics in position |ψ(x)²| and momentum space |ψ(p)²| versus time show quantum localization in both momentum and position space. Also, we discuss the parametric dependencies of dynamical localization for a designated set of parameters to be experimentally feasible. Our work opens an avenue to manipulate the other optical phenomena and applicability of proposed work can be prolonged to turn-able laser sources in the future.Keywords: dynamical localization, cavity optomechanics, Hamiltonian chaos, probe field
Procedia PDF Downloads 150292 Neural Adaptive Controller for a Class of Nonlinear Pendulum Dynamical System
Authors: Mohammad Reza Rahimi Khoygani, Reza Ghasemi
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In this paper, designing direct adaptive neural controller is applied for a class of a nonlinear pendulum dynamic system. The radial basis function (RBF) is used for the Neural network (NN). The adaptive neural controller is robust in presence of external and internal uncertainties. Both the effectiveness of the controller and robustness against disturbances are the merits of this paper. The promising performance of the proposed controllers investigates in simulation results.Keywords: adaptive control, pendulum dynamical system, nonlinear control, adaptive neural controller, nonlinear dynamical, neural network, RBF, driven pendulum, position control
Procedia PDF Downloads 670291 Calculating Non-Unique Sliding Modes for Switched Dynamical Systems
Authors: Eugene Stepanov, Arkadi Ponossov
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Ordinary differential equations with switching nonlinearities constitute a very useful tool in many applications. The solutions of such equations can usually be calculated analytically if they cross the discontinuities transversally. Otherwise, one has trajectories that slides along the discontinuity, and the calculations become less straightforward in this case. For instance, one of the problems one faces is non-uniqueness of the sliding modes. In the presentation, it is proposed to apply the theory of hybrid dynamical systems to calculate the solutions that are ‘hidden’ in the discontinuities. Roughly, one equips the underlying switched system with an explicitly designed discrete dynamical system (‘automaton’), which governs the dynamics of the switched system. This construction ‘splits’ the dynamics, which, as it is shown in the presentation, gives uniqueness of the resulting hybrid trajectories and at the same time provides explicit formulae for them. Projecting the hybrid trajectories back onto the original continuous system explains non-uniqueness of its trajectories. The automaton is designed with the help of the attractors of the specially constructed adjoint dynamical system. Several examples are provided in the presentation, which supports the efficiency of the suggested scheme. The method can be of interest in control theory, gene regulatory networks, neural field models and other fields, where switched dynamics is a part of the analysis.Keywords: hybrid dynamical systems, singular perturbation analysis, sliding modes, switched dynamics
Procedia PDF Downloads 162290 Hunting Ban, Unfortunate Decisions for the Bear Population in Romania
Authors: Alexandru Gridan, Georgeta Ionescu, Ovidiu Ionescu, Ramon Jurj, George Sirbu, Mihai Fedorca
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The Brown Bear population size in Romania is approximately 7300-7600 individuals, which is projected to be 3000 individuals over the ecological carrying capacity. The Habitats Directive imposed certain protection rules on European Union (EU) Member States with Brown Bear populations. These however allow countries like Sweden, Croatia, Slovakia, Estonia to hunting as management tool, harvesting up to 10% of the surplus bear population annually. From the point Romania joined the EU to 2016, active conservation management has contributed to maintaining the highest and most genetically diverse Brown Bear population in Europe. Importantly, there has been good coexistence between people and bears and low levels of human-bear conflict. After social pressure and campaigning by some non-governmental organisations citing issues over monitoring, the environment minister decided in September 2016 to stop the use of hunting as a management tool for bears. Against this background, this paper provides a set of recommendations to resolve the current conflict in Romania. These include the need for collaborative decision-making to reduce conflicts between stakeholders and mechanisms to reduce current human-bear conflicts, which have increased by 50 percent in the past year.Keywords: bear, bear population, bear management, wildlife conflict
Procedia PDF Downloads 182289 Feeding Ecology and Habitat Preference of Red Panda in Dhorpatan Hunting Reserve, Nepal
Authors: Saroj Panthi
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The red panda (Ailurus fulgens fulgens) is distributed throughout the Himalayas and is found in both protected and unprotected areas of Nepal. Loss and fragmentation of habitat threaten red panda population throughout its range, and as a consequence, it is listed as vulnerable on the IUCN Red List of Threatened Species. Despite this pressing situation, data on the ecology of the red panda in western Nepal are lacking. Our aim in the current study was to determine the distribution, associated habitats, and summer diet of the red panda in Dhorpatan Hunting Reserve (DHR), Nepal. Evidence of red pandas was found in all 7 blocks of the reserve, spanning an area of 345.8 km2, between elevations of 2800 m and 4000 m and predominantly (> 75%) in forests comprising plant communities dominated by Abies spectabilis, Acer caesium, Tsuga domusa, and Betula utilis, with ground cover of Arundinaria spp. The dominant plant found in scat of the red panda was Arundinaria spp. (81.7%), with Acer spp., B. utilis, and lichen also frequently present. Livestock grazing and human activities were significantly higher in habitats where signs of pandas were recorded than in areas where they were absent. This habitat overlap between the red panda and livestock potentially poses a major threat to the panda’s survival in the DHR, a fact that should be taken into account in devising management strategies for this threatened species.Keywords: red panda, Dhorpatan hunting reserve, diet, habitat preference
Procedia PDF Downloads 343288 X-Ray Dynamical Diffraction Rocking Curves in Case of Third Order Nonlinear Renninger Effect
Authors: Minas Balyan
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In the third-order nonlinear Takagi’s equations for monochromatic waves and in the third-order nonlinear time-dependent dynamical diffraction equations for X-ray pulses for forbidden reflections the Fourier-coefficients of the linear and the third order nonlinear susceptibilities are zero. The dynamical diffraction in the nonlinear case is related to the presence in the nonlinear equations the terms proportional to the zero order and the second order nonzero Fourier coefficients of the third order nonlinear susceptibility. Thus in the third order nonlinear Bragg diffraction case a nonlinear analogue of the well known Renninger effect takes place. In this work, the ‘third order nonlinear Renninger effect’ is considered theoretically and numerically. If the reflection exactly is forbidden the diffracted wave’s amplitude is zero both in Laue and Bragg cases since the boundary conditions and dynamical diffraction equations are compatible with zero solution. But in real crystals due to some percent of dislocations and other localized defects, the atoms are displaced with respect to their equilibrium positions. Thus in real crystals susceptibilities of forbidden reflection are by some order small than for usual not forbidden reflections but are not exactly equal to zero. The numerical calculations for susceptibilities two order less than for not forbidden reflection show that in Bragg geometry case the nonlinear reflection curve’s behavior is the same as for not forbidden reflection, but for forbidden reflection the rocking curves’ width, center and boundaries are two order sensitive on the input intensity value. This gives an opportunity to investigate third order nonlinear X-ray dynamical diffraction for not intense beams – 0.001 in the units of critical intensity.Keywords: third order nonlinearity, Bragg diffraction, nonlinear Renninger effect, rocking curves
Procedia PDF Downloads 406287 Finite Time Blow-Up and Global Solutions for a Semilinear Parabolic Equation with Linear Dynamical Boundary Conditions
Authors: Xu Runzhang, Yang Yanbing, Niu Yi, Zhang Mingyou, Liu Yu
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For a class of semilinear parabolic equations with linear dynamical boundary conditions in a bounded domain, we obtain both global solutions and finite time blow-up solutions when the initial data varies in the phase space H1(Ω). Our main tools are the comparison principle, the potential well method and the concavity method. In particular, we discuss the behavior of the solutions with the initial data at critical and high energy level.Keywords: high energy level, critical energy level, linear dynamical boundary condition, semilinear parabolic equation
Procedia PDF Downloads 436286 Periodically Forced Oscillator with Noisy Chaotic Dynamics
Authors: Adedayo Oke Adelakun
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The chaotic dynamics of periodically forced oscillators with smooth potential has been extensively investigated via theoretical, numerical and experimental simulations. With the advent of the study of chaotic dynamics by means of method of multiple time scale analysis, Melnikov theory, bifurcation diagram, Poincare's map, bifurcation diagrams and Lyapunov exponents, it has become necessary to seek for a better understanding of nonlinear oscillator with noisy term. In this paper, we examine the influence of noise on complex dynamical behaviour of periodically forced F6 - Duffing oscillator for specific choice of noisy parameters. The inclusion of noisy term improves the dynamical behaviour of the oscillator which may have wider application in secure communication than smooth potential.Keywords: hierarchical structure, periodically forced oscillator, noisy parameters, dynamical behaviour, F6 - duffing oscillator
Procedia PDF Downloads 325285 A Regional Comparison of Hunter and Harvest Trends of Sika Deer (Cervus n. nippon) and Wild Boar (Sus s. leucomystax) in Japan from 1990 to 2013
Authors: Arthur Müller
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The study treats human dimensions of hunting by conducting statistical data analysis and providing decision-making support by examples of good prefectural governance and successful wildlife management, crucial to reduce pest species and sustain a stable hunter population in the future. Therefore it analyzes recent revision of wildlife legislation, reveals differences in administrative management structures, as well as socio-demographic characteristics of hunters in correlation with harvest trends of sika deer and wild boar in 47 prefectures in Japan between 1990 and 2013. In a wider context, Japan’s decentralized license hunting system might take the potential future role of a regional pioneer in East Asia. Consequently, the study contributes to similar issues in premature hunting systems of South Korea and Taiwan. Firstly, a quantitative comparison of seven mainland regions was conducted in Hokkaido, Tohoku, Kanto, Chubu, Kinki, Chugoku, and Kyushu. Example prefectures were chosen by a cluster analysis. Shifts, differences, mean values and exponential growth rates between trap and gun hunters, age classes and common occupation types of hunters were statistically exterminated. While western Japan is characterized by high numbers of aged trap-hunters, occupied in agricultural- and forestry, the north-eastern prefectures show higher relative numbers of younger gun-hunters occupied in the field of production and process workers. With the exception of Okinawa island, most hunters in all prefectures are 60 years and older. Hence, unemployed and retired hunters are the fastest growing occupation group. Despite to drastic decrease in hunter population in absolute numbers, Hunting Recruitment Index indicated that all age classes tend to continue their hunting activity over a longer period, above ten years from 2004 to 2013 than during the former decade. Associated with a rapid population increase and distribution of sika deer and wild boar since 1978, a number of harvest from hunting and culling also have been rapidly increasing. Both wild boar hunting and culling is particularly high in western Japan, while sika hunting and culling proofs most successful in Hokkaido, central and western Japan. Since the Wildlife Protection and Proper Hunting Act in 1999 distinct prefectural hunting management authorities with different power, sets apply management approaches under the principles of subsidiarity and guidelines of the Ministry of Environment. Additionally, the Act on Special Measures for Prevention of Damage Related to Agriculture, Forestry, and Fisheries Caused by Wildlife from 2008 supports local hunters in damage prevention measures through subsidies by the Ministry of Agriculture and Forestry, which caused a rise of trap hunting, especially in western Japan. Secondly, prefectural staff in charge of wildlife management in seven regions was contacted. In summary, Hokkaido serves as a role model for dynamic, integrative, adaptive “feedback” management of Ezo sika deer, as well as a diverse network between management organizations, while Hyogo takes active measures to trap-hunt wild boars effectively. Both prefectures take the leadership in institutional performance and capacity. Northern prefectures in Tohoku, Chubu and Kanto region, firstly confronted with the emergence of wild boars and rising sika deer numbers, demand new institution and capacity building, as well as organizational learning.Keywords: hunting and culling harvest trends, hunter socio-demographics, regional comparison, wildlife management approach
Procedia PDF Downloads 281284 Reconstruction and Rejection of External Disturbances in a Dynamical System
Authors: Iftikhar Ahmad, A. Benallegue, A. El Hadri
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In this paper, we have proposed an observer for the reconstruction and a control law for the rejection application of unknown bounded external disturbance in a dynamical system. The strategy of both the observer and the controller is designed like a second order sliding mode with a proportional-integral (PI) term. Lyapunov theory is used to prove the exponential convergence and stability. Simulations results are given to show the performance of this method.Keywords: non-linear systems, sliding mode observer, disturbance rejection, nonlinear control
Procedia PDF Downloads 334283 Human Pressure Threaten Swayne’s Hartebeest to Point of Local Extinction from the Savannah Plains of Nech Sar National Park, South Rift Valley, Ethiopia
Authors: Simon Shibru, Karen Vancampenhout, Jozef Deckers, Herwig Leirs
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We investigated the population size of the endemic and endangered Swayne’s Hartebeest (Alcelaphus buselaphus swaynei) in Nech Sar National Park from 2012 to 2014 and document the major threats why the species is on the verge of local extinction. The park was once known for its abundant density of Swayne’s Hartebeest. We used direct total count methods for a census. We administered semi-structured interviews and open-ended questionnaires with senior scouts who are the member of the local communities. Historical records were obtained to evaluate the population trends of the animals since 1974. The density of the animal decreased from 65 in 1974 to 1 individual per 100 km2 in 2014 with a decline of 98.5% in the past 40 years. The respondents agreed that the conservation status of the park was in its worst condition ever now with only 2 Swayne’s Hartebeest left, with a rapid decline from 4 individuals in 2012 and 12 individuals in 2009. Mainly hunting and habitat loss, but also the unsuitable season of reproduction and shortage of forage as minor factors were identified as threats for a local extinction of the Swayne’s Hartebeests. On the other hand, predation, fire, disease, and ticks were not considered a cause for the declining trend. Hunting happens mostly out of some kind of revenge since the local community thought that they were pushed out from the land because of the presence of Swayne's Hartebeest in the area. Respondents agreed that the revenge action of the local communities was in response to their unwillingness to be displaced from the park in 1982/3. This conflict situation is resulting from the exclusionary wildlife management policy of the country. We conclude that the human interventions in general and illegal hunting, in particular, pushed the Swayne’s Hartebeest to a point of local extinction. Therefore, we recommend inclusive wildlife management approach for continuing existence of the park together with its natural resources so that sustainable use of the resources is in place.Keywords: hunting, habitat destruction, local extinction, Nech Sar National Park, Swayne’s Hartebeest
Procedia PDF Downloads 474282 An Inverse Optimal Control Approach for the Nonlinear System Design Using ANN
Authors: M. P. Nanda Kumar, K. Dheeraj
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The design of a feedback controller, so as to minimize a given performance criterion, for a general non-linear dynamical system is difficult; if not impossible. But for a large class of non-linear dynamical systems, the open loop control that minimizes a performance criterion can be obtained using calculus of variations and Pontryagin’s minimum principle. In this paper, the open loop optimal trajectories, that minimizes a given performance measure, is used to train the neural network whose inputs are state variables of non-linear dynamical systems and the open loop optimal control as the desired output. This trained neural network is used as the feedback controller. In other words, attempts are made here to solve the “inverse optimal control problem” by using the state and control trajectories that are optimal in an open loop sense.Keywords: inverse optimal control, radial basis function, neural network, controller design
Procedia PDF Downloads 553281 Solving Ill-Posed Initial Value Problems for Switched Differential Equations
Authors: Eugene Stepanov, Arcady Ponosov
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To model gene regulatory networks one uses ordinary differential equations with switching nonlinearities, where the initial value problem is known to be well-posed if the trajectories cross the discontinuities transversally. Otherwise, the initial value problem is usually ill-posed, which lead to theoretical and numerical complications. In the presentation, it is proposed to apply the theory of hybrid dynamical systems, rather than switched ones, to regularize the problem. 'Hybridization' of the switched system means that one attaches a dynamic discrete component ('automaton'), which follows the trajectories of the original system and governs its dynamics at the points of ill-posedness of the initial value problem making it well-posed. The construction of the automaton is based on the classification of the attractors of the specially designed adjoint dynamical system. Several examples are provided in the presentation, which support the suggested analysis. The method can also be of interest in other applied fields, where differential equations contain switchings, e.g. in neural field models.Keywords: hybrid dynamical systems, ill-posed problems, singular perturbation analysis, switching nonlinearities
Procedia PDF Downloads 184