Forbidden Zones Research Articles

Formation of unmanned aircraft trajectory when flying around prohibited areas

Considered the problem of flying over restricted areas by an unmanned aerial vehicle (UAV), which have various shapes and restrictions, set on the basis of the international airspace classification system for aviation in accordance with the Chicago Convention and the recommended principles for the formation of forbidden zones, rules for creating a flight route along forbidden zones and actions in case of border violations of restricted areas. The problem of analytical synthesis of the control acceleration of an unmanned aerial vehicle (UAV) is solved during its flight along a route passing along the boundaries of the forbidden zone of a given shape, along a given trajectory, which consists of subsequent segments located at the same height relative to the earth’s surface, in a given coordinate system. The optimal control synthesis problem is solved as an analytical definition of the optimal control of a linear non-stationary system based on the quadratic quality functional. A mathematical model of UAV motion in the horizontal plane is proposed, in the form of a system of ordinary differential equations in the Cauchy form. A law for measuring the control acceleration of the UAV’s center of mass is obtained on the basis of specifying the minimized quality functional and the corresponding constraints, which is a feature of the considered method of solving the problem. The proposed quality functional takes into account the parameters of coordinates and speed of the UAV, which correspond to the given points in the airspace, which characterize the necessary trajectory for flying around the restricted area. The derived mathematical dependences make it possible to implement them on board a UAV and minimize energy costs when guiding a UAV moving through specified points in space. Computer modeling of the derived analytical results, mathematical dependencies representing the optimal trajectory of the UAV flight along the boundaries of the forbidden zone, as well as the corresponding processes of changing the control acceleration and speed of the UAV movement was carried out, which made it possible to draw conclusions about the efficiency of the proposed method and the feasibility of its further use as a basis. for the initial stage of the synthesis of the UAV control system.

Hydrothermal Unit-Commitment Problem of a Large-Scale System with Representation of Forbidden Zones

As we move towards electrical networks with a growing presence of renewable generation, the representation of the electrical components becomes more important. In hydro-dominated power systems, modelling the forbidden zones of hydro plants becomes increasingly challenging as the number of plants increases. Such zones are ranges of generation that either should be avoided or are altogether unreachable. However, because representing the forbidden zones introduces a substantial computational burden, hydrothermal unit-commitment problems (HTUC) for large systems are usually formulated ignoring the forbidden zones. Nonetheless, this simplification may demand adjustments to the solution of the HTUC, because the generation of the hydro stations may fall in forbidden zones. In practice, the adjustments are usually performed based on the experience of system operators and, then, can be far from an optimal correction. In this paper, we study the impact of explicitly representing the hydro-generation forbidden zones in a large-scale system with more than 7000 buses, 10,000 lines, and 700 hydro units. Our findings show that the simplified model that is current used can deviate significantly from the model with forbidden zones, both in terms of the generation of hydro plants, as well as the generation of thermal plants and the system marginal costs.

Forbidden Zones for the Expectations of Data: New Mathematical Methods and Models for Behavioral Economics

A forbidden zone theorem, hypothesis, and applied mathematical method and model are introduced in the present article. The method and model are based on the forbidden zones and hypothesis. The article is initiated by the well-known generic problems concerned with the mathematical description of the behavior of a man. The essence of the problems consists in biases of preferences and decisions of a man in comparison with predictions of the probability theory. The model is uniformly and successfully applied for different domains. The ultimate goal of the research is to solve some generic problems of behavioral economics, decision theories, and the social sciences.

Optimization of location of interconnected facilities on parallel lines with forbidden zones

Optimization of location of interconnected facilities on parallel lines with forbidden zones

Optimization of the Location of Interconnected Facilities on Parallel Lines with Forbidden Zones

Optimization of the Location of Interconnected Facilities on Parallel Lines with Forbidden Zones

Solving Nonsmooth and Discontinuous Optimal Power Flow problems via interior-point [formula omitted]-penalty approach

The Nonsmooth and Discontinuous Optimal Power Flow (ND-OPF) is a large-scale, nonsmooth, discontinuous, nonconvex and multi-modal problem. In this problem, discontinuity is related to the representation of Prohibited Operating Zones (POZ), whereas nonsmoothness is related to the representation of Valve-Point Loading Effect (VPLE) in the fuel costs. Due to such features, all approaches that have been proposed for solving this problem are based on heuristics or on mixed integer nonlinear programming reformulations. In this paper, we propose the Piecewise Polynomial Interpolation (PPI) function approach for handling discontinuities related to the POZ constraints, which consists in replacing such constraints by an equivalent set of smooth and continuous equality and inequality constraints. The PPI function is of class C1 and assumes null values at all allowed operating zones and non-null values at all forbidden zones. The model resulting from the PPI approach is the Equivalent Intermediate Model (EIM). For handling nonsmoothness on the EIM, we recast it as an equivalent model, where the VPLE term in the objective function becomes linear, and nonlinear box inequality constraints are introduced. The optimization model that results from such recasts is the Equivalent Smooth and Continuous OPF(ESC-OPF) model proposed, which can be solved by strictly gradient-based methods. Finally, we propose a primal–dual interior point ℓp-penalty approach (with 0<p≤1) for solving the ESC-OPF model, where inequality constraints are penalized by using the modified log-barrier function of Jittortrum–Osborne–Meggido and the equality constraints associated with the PPI function approach are penalized via ℓp lower-order exact penalty functions. Numerical results involving systems with up to 2007 buses, with 282 generating units and 846 POZ have shown that the proposed approach has been able to solve large-scale ND-OPF problems, with acceptable computation times.

Ecological security evaluation and ecological regulation approach of East-Liao River basin based on ecological function area

Watershed ecological security provides the basic guarantee of regional sustainable development; thus, reliable watershed ecological security evaluation is of great significance in revealing the watershed ecological security status and promoting the healthy development of the watershed society and ecological environment. To construct the ecological function area, this study used the East-Liao River basin as the analysis object and discussed the delimitation method of ecological security evaluation, which provided the reference and basis for studying and exploring the optimal ecological regulation method of the basin. The following results were obtained: from 2000 to 2020, the regions with lower ecological security index changed from northwest to southeast of the watershed, and presented the spatial distribution of “unsafe” → “generally safe” → “relatively safe” → “safe”, with the center of gravity concentrated in the middle of the watershed; the spatial differences of ecological security became significant with the addition of ecological function zones, and they show a certain spatial aggregation trend; from 2000 to 2020, the ecological security level was predominantly safer, and the distribution of gravity center showed a circular state; the ecological security level of the watershed can be improved by adjusting the proportion of regional land use types. According to the results, countermeasures and approaches of watershed ecological security regulation were suggested, and four subareas were established: forbidden development zones, traditional utilization zones, ecologically sensitive/fragile zones, and key ecological function zones; this would provide a basis for further analysis of environmental governance in the East-Liao River basin of Jilin Province. Nevertheless, the countermeasures and approaches of ecological security regulation proposed in this study will also be useful for land use planning and runoff management in other watersheds around the world.

Forbidden zones: War Nurse (1930), women, and the Hollywood memory of the Great War

ABSTRACT While women working as nurses had been a staple in films with war settings since the beginnings of narrative film, the early 1930s saw a short cycle of Hollywood films which placed women at the centre of the war film. One of the first of these was War Nurse (1930), produced at MGM and directed by Edgar Selwyn. Another, a year later, was The Mad Parade, a film distributed by Paramount and directed by William Beaudine. The two films did unremarkable business and their critical reception ranged from lukewarm to outright hostile. Yet this cycle is an illuminating instance of the Hollywood system’s negotiation with the evolving public memories of the Great War. Both films were efforts to widen the appeal of the war as a film subject to the assumed interest of women audiences. They drew attention to women’s agency, their experiences and their ability to deal with male weakness and aggression, both physical and sexual, and in the process offered an alternative perspective on desire at the Front that had remained underexplored in the male adventure film. In these films the Front and the environments surrounding it were ‘a forbidden zone’ where the term was polysemic, forbidden in terms of the threat of death, sexual exploitation, and violence, but also in the promise of escape from moral strictures. In this environment, straight-talking vernacular was a coping mechanism. This chapter outlines how Hollywood scriptwriter Becky Gardner incorporated slang and wisecracking as a technique of realism and as a means of sidestepping censorship in constructing an alternative public memory of the Great War.

Молекулярно-динамический анализ транспорта энергии в кристалле Pt3Al при воздействии в запрещенной зоне спектра

Сonstant search for new mechanisms of energy transport associated with a decrease in losses results in the active investigation of the possibilities of generating mobile excitations at frequencies outside the phonon spectrum. The effect of energy transfer at frequencies outside the band, possible in case if the excitation amplitude exceeds the critical value, was previously actively studied in reduced dimension systems. In this work, for the first time, the possibility and features of energy transfer at frequencies outside the phonon spectrum of a crystal are studied on the Pt3Al biatomic lattice, the corresponding excitations in which are created through the implementation of harmonic vibrations at frequencies lying in the phonon spectrum gap. It was found that as a result of the initial impact, the parameters of which lie in the band gap, at the first stage, discrete breathers are formed on aluminum atoms lying in the immediate vicinity of the impact zone. The threshold value of the energy required to excite breathers, determined by the amplitude and frequency of exposure, decreases as the frequency approaches the boundary of the slit in the spectrum. At the second stage, after the end of the harmonic action, a soliton-like wave is formed, moving along the crystal with an average speed of 4.5 km / s. The wave velocity is practically independent of the initial disturbance amplitude. The shape and amplitude of the moving wave are weakly dependent on the initial frequency. Significant differences in the profile and a tendency to bimodality were revealed only when exposed to frequencies close to the lower limit of the spectrum. The results obtained contribute to a fundamental understanding of the features of the propagation of elastic disturbances in nonlinear media in case of forbidden zones region impacts.

Piecewise linear approximations for hydropower production function applied on the hydrothermal unit commitment problem

In a centralized-based dispatch market, the network-constrained hydrothermal unit commitment (NCHTUC) determines generation decisions that minimize the expected operating cost, usually in a day-ahead planning horizon. In this context, hydropower offers unique flexibility features, and an adequate representation is crucial for overcoming operation challenges. However, due to computational burden, simplifications on hydropower production function (HPF) modeling are necessary since NCHTUC is a large-scale nonlinear discrete optimization problem. The plant-based HPF piecewise linear approach is the most common simplification presented for real-life cases. In this case, the generating units (GUs) of a plant are aggregated and represented by a single equivalent generator. Although this approach reduces the size and the complexity of the NCHTUC significantly, several operating issues are not considered adequately, especially the forbidden zones and the nonlinearities of the GUs. In this paper, we present a new approach that considers the nonlinearities and forbidden zones of the HPF via aggregation of the GUs and piecewise mixed-integer linear approximation in an innovative way. Experiments are performed in a modified version of the IEEE 118-bus system to verify the approach’s effectiveness, analyzed in terms of the relation between computation burden and the HPF approximation quality.

New polymorphic varieties of graphyne formed on the basis of 5-7b graphene: Ab initio calculations

The crystal and electronic structure of 16 new polymorphic varieties of sp+sp2 graphyne layers was calculated by the density functional theory method in the gradient approximation. The primary structure of the graphyne layers was constructed by replacing the interatomic bonds in the graphene layers 5-7b with carbyne chain fragments. Ab initio calculations have shown that out of 29 modeled structures only sixteen are stable: 14 β-type layers and one α- and γ-type layer each. During optimization 13 graphyne layers were transformed into graphene layers or into graphyne layers with a smaller relative number of sp-hybridized atoms. The electronic properties of most of the new graphyne layers are metallic, since the density of electronic states at the Fermi energy level for them is different from zero. There are forbidden zones in the electronic structure of the seven layers, but their value is small and varies from 0.05 to 0.20 eV.

Reinforcement Learning-Based Approximate Optimal Control for Attitude Reorientation Under State Constraints

This article addresses the attitude reorientation problems of rigid bodies under multiple state constraints. A novel reinforcement learning (RL)-based approximate optimal control method is proposed to make the tradeoff between control cost and performance. The novelty lies in that it guarantees constraint handling abilities on attitude forbidden zones and angular velocity limits. To achieve this, barrier functions are employed to encode the constraint information into the cost function. Then, an RL-based learning strategy is developed to approximate the optimal cost function and control policy. A simplified critic-only neural network (NN) is employed to replace the conventional actor–critic structure once adequate data are collected online. This design guarantees the uniform boundedness of reorientation errors and NN weight estimation errors subject to the satisfaction of a finite excitation condition, which is a relaxation compared with the persistent excitation condition that is typically required for this class of problems. More importantly, all underlying state constraints are strictly obeyed during the online learning process. The effectiveness and advantages of the proposed controller are verified by both numerical simulations and experimental tests based on a comprehensive hardware-in-loop testbed.

Fractionally charged anyons generated by topological path fusion of propagating electron in magnetic flux lattice

Anyon is collective excitation of two dimensional electron gas subjected to strong magnetic field, carrying fractional charges and exotic statistical character beyond fermion and boson. So far, anyons with serial fractional charges only exist in fractional quantum Hall effect. It is still a challenge to find new serial of fractional charges in other physical system and develop an unified mathematical physics theory based on the same root. Here a topological path fusion theory of propagating electrons in magnetic flux lattice is proposed to explore the physical origin of fractional charges based on a generalization of Feynman's path integral theory and Thurston's train track theory. This mathematical physics theory generated the existed serial of fractional charges in fractional quantum Hall effect and predicted new serial of fractional charges. A serial of irrational charges are predicted in one dimensional lattice of magnetic fluxes. Fractionally charged anyons are also generated in two dimensional and three dimensional lattice of train tracks of electric currents, revealing an exact correspondence between knot lattice model and train track model. A new explanation for the modular symmetry of complex Hall conductance and composite fermion in fractional quantum Hall effect is also derived from this topological path fusion theory. Experimental observation of anyon in three dimensions can be realized by constructing three dimensional interlocking magnetic fluxes or mapping magnetic fluxes into forbidden zones in multi-connected space filled by solid state material. A photonic crystal with porous nano-structures is a promising system for detecting fractional charges and paves a new way for topological quantum computation.

Research minimax and minisum Weber problems on a plane with forbidden zones

Weber problem is a well–known location problem of connected facilities. Two optimality criteria are considered. The first criterion is minimization of the total cost of connections among facilities. The second criterion is minimization of the maximum connection between facilities. This article deals with Weber problems on a plane with rectangular forbidden zones. Location inside in the forbidden zones is not allowed. The sides of forbidden zones are parallel to the coordinate axes. To measure distances rectangular metric is used. An overview of studies for these problems is provided. Some properties of the problems are described. For example, the possibilities of reduction of admissible areas in the search for an optimal solution are presented. Variants of different bounds of the objective functions are provided. Models of integer linear programming with Boolean variables are given. Computational experiments with using the branch and bound algorithms, the constructed models and IBM ILOG CPLEX package were carried out. Usage of the properties of reductions of admissible areas is promising both in solving of the problems by combinatorial methods and using the integer optimization apparatus.

Online path planning for unmanned aerial vehicles to maximize instantaneous information

In this article, an online path planning algorithm for multiple unmanned aerial vehicles (UAVs) has been proposed. The aim is to gather information from target areas (desired regions) while avoiding forbidden regions in a fixed time window starting from the present time. Vehicles should not violate forbidden zones during a mission. Additionally, the significance and reliability of the information collected about a target are assumed to decrease with time. The proposed solution finds each vehicle’s path by solving an optimization problem over a planning horizon while obeying specific rules. The basic structure in our solution is the centralized task assignment problem, and it produces near-optimal solutions. The solution can handle moving, pop-up targets, and UAV loss. It is a complicated optimization problem, and its solution is to be produced in a very short time. To simplify the optimization problem and obtain the solution in nearly real time, we have developed some rules. Among these rules, there is one that involves the kinematic constraints in the construction of paths. There is another which tackles the real-time decision-making problem using heuristics imitating human-like intelligence. Simulations are realized in MATLAB environment. The planning algorithm has been tested on various scenarios, and the results are presented.

Optimal layout of a Co-Located wind/tidal current farm considering forbidden zones

Co-location of wind and tidal current turbines (WTs/TCTs) is a new way to improve the economy and reliability of electricity generation from renewable energy sources. In this paper, an optimization model for determining the configuration of a co-located wind/tidal current farm (WF/TCF) is proposed. The objectives include the minimization of the system levelized cost of energy (LCOE) and the maximization of the system average power supply reliability (APSR). In the planning area, there are certain zones where there are important restrictions which do not allow WTs/TCTs to be installed. These are called forbidden zones. When deciding the feasible area in the optimization, the complement of the forbidden zones in the planning area is used. The optimization problem is formulated as a coordinate model (CM) and a grid model (GM), both solved by the multi-swarm optimization (MSO) algorithm. The proposed approach is tested in an offshore area of Zhejiang province, China. Simulation results indicate that the co-location of a WF/TCF is an economic-technical efficient approach to harvest marine renewable energy. Also, the MSO algorithm outperforms its counterparts, the particle swarm optimization (PSO) and the discrete particle swarm optimization (DPSO) algorithms, in solving the CM and the GM of the WF/TCF layout optimization problem.

Numerical research of placement problem on lines with forbidden zones and routing communications

This paper discusses of placement problem of connected equipment (facilities) on parallel lines with forbidden zones. You can’t place equipment inside of forbidden zones. The facilities are connected among themselves and with zones by some kind of communications. The communications (routing of communications) between the facilities and between facilities and zones located on adjacent lines pass through the vertical equipment (viaduct). The target is to find the facilities placement on lines outside zones. Facilities do not must intersect among themselves. It is necessary to minimize the total cost of communications facilities among themselves and with zones. Practical usage of this problem is found, for example, in technology in the design of engineering devices. We consider cases when the viaduct placement is fixed and when its optimal placement is found. The goal function’s value for a fixed viaduct with a specified placement step is compared with the goal function for optimal placement of the viaduct. The results of numerical experiments are presented.

Edge-oriented and steerable hyperbolic polaritons in anisotropic van der Waals nanocavities

Highly confined and low-loss polaritons are known to propagate isotropically over graphene and hexagonal boron nitride in the plane, leaving limited degrees of freedom in manipulating light at the nanoscale. The emerging family of biaxial van der Waals materials, such as α-MoO3 and V2O5, support exotic polariton propagation, as their auxiliary optical axis is in the plane. Here, exploiting this strong in-plane anisotropy, we report edge-tailored hyperbolic polaritons in patterned α-MoO3 nanocavities via real-space nanoimaging. We find that the angle between the edge orientation and the crystallographic direction significantly affects the optical response, and can serve as a key tuning parameter in tailoring the polaritonic patterns. By shaping α-MoO3 nanocavities with different geometries, we observe edge-oriented and steerable hyperbolic polaritons as well as forbidden zones where the polaritons detour. The lifetime and figure of merit of the hyperbolic polaritons can be regulated by the edge aspect ratio of nanocavity.

Large-Scale Unit Commitment for Cascaded Hydropower Plants with Hydraulic Coupling and Head-Sensitive Forbidden Zones: Case of the Xiluodu and Xiangjiaba Hydropower System

AbstractThis study presents a methodology for optimizing the unit commitment (UC) of the Xiluodu and Xiangjiaba cascaded hydropower plants that rank as the second- and third-largest hydropower plan...

Design of intelligent surveillance system based on wireless ad-hoc network under special conditions

For oil fields, shooting target range, military forbidden zones and other special complex scenarios, it is not only difficult to deploy communication infrastructure because of its remote location and difficult environment, but also difficult to transmit surveillance video images to command stations in real time through centralized communication networks. Furthermore, there is a waste of bandwidth resources and the use of wireless ad hoc networks to transmit surveillance video. Therefore, we aim at designing and implementing a real-time intelligent surveillance system based on wireless ad-hoc networks in special scenes in this project. The system is supposed to capture the video frames of the monitored area and perform automatic intrusion detection. Only when an intrusion is detected, the video frame is encoded and transmitted together with the alarm message to the command center. An improved Yolov2 algorithm to achieve real time object detection on a computationally limited platform was proposed first. A wireless ad-hoc communication system was designed and implemented on the basic of the Tactical Targeting Network Technology (TTNT) Data Link to transmit surveillance video stream, control signaling and alarm message. Then the extensive experiments were conducted to evaluate the system in terms of detection accuracy and communication performance. The experiments results demonstrate the effectiveness and accuracy of the proposed system, the size of the model is only 7.6% of Yolov2 and the detection speed is increased 4 times. This design transforms long-time data transmission into burst data transmission, thus saving bandwidth resources and improving bit error rate of 96.9%. It is of great significance for the future application of artificial intelligence and machine learning in the field of communication