Law Constraints Research Articles

Electric-dual BPS vortices in the generalized self-dual Maxwell-Chern-Simons-Higgs model

In this paper we show how to derive the Bogomolny’s equations of the generalized self-dual Maxwell-Chern-Simons-Higgs model presented in [10] by using the BPS Lagrangian method with a particular choice of the BPS Lagrangian density. We also show that the identification, potential terms, and Gauss’s law constraint can be derived rigorously under the BPS Lagrangian method. In this method, we find that the potential terms are the most general form that could have the BPS vortex solutions. The Gauss’s law constraint turns out to be the Euler–Lagrange equations of the BPS Lagrangian density. We also find another BPS vortex solutions by taking other identification between the neutral scalar field and the electric scalar potential field, N = ± A 0, which is different by a relative sign to the identification in [10], N = ∓ A 0. Under this identification, N = ± A 0, we obtain a slightly different potential terms and Bogomolny’s equations compared to the ones in [10]. Furthermore we compute the solutions numerically, with the same configurations as in [10], and find that only the resulting electric field plots differ by sign relative to the results in [10]. Therefore we conclude that these BPS vortices are electric-dual BPS vortices of the ones computed in [10].

A Data-Driven Linear Optimal Power Flow Model for Distribution Networks

The linearized power flow (PF) model is mainly used to make the optimal power flow (OPF) problem convex. However, existing data-driven linear PF models are not applicable for OPF calculation since the Kirchhoff's law (KCL) constraints are neglected. In this letter, we propose a data-driven linear PF model incorporating the KCL constraints and can be embedded in OPF for distribution networks (DNs). By combining the support vector regression (SVR) and ridge regression (RR) algorithms, the proposed method is robust against bad data in measurements. Numerical tests show that the proposed model has much higher accuracy than the existing linear models, especially for OPF calculation.

India's Nuclear Question: Resolving Superpower Aspirations with International Law Constraints

India's Nuclear Question: Resolving Superpower Aspirations with International Law Constraints

How the Erosion of U.S. War Powers Constraints Has Eroded International Law Constraints on the Use of Force

How the Erosion of U.S. War Powers Constraints Has Eroded International Law Constraints on the Use of Force

Novel modular powertrain proposal for e-bicycle

Bicycles with electric pedal assist systems are becoming increasingly popular, with increasing versatility, a range of intended areas of use, and different design approaches for system realization. This paper deals with the proposal for a novel modular drivetrain concept based on a friction driving wheel, for which a brief design outline is given. Desired performances based on law constraints and average bicycle driving experience analysed, and basic powertrain properties required for their realization assessed.

Tapajós

“Tapajós” narrates the field campaign of two researchers studying forest fragmentation in the Brazilian Amazon. It addresses a contemporary conflict in the region, where an Indigenous people, the Munduruku, are resisting efforts by the Brazilian State to channelize the Tapajós River and exploit its hydropower potential. Development here represents an existential threat to the Munduruku, whose homeland resides in the river valley. It also represents an ecological threat to the global community. Although the rate of deforestation dropped after the turn of the millennium, it has begun to climb again and would no doubt accelerate with development in the Tapajós watershed and the opening of Central Amazonia to colonization and resource extraction. This would push the forest past its tipping point, a magnitude of deforestation capable of compromising rainfall recycling, and thus precipitating the transformation of the Amazonian forest into a patchwork of fireadapted shrubs and grasses. “Tapajós” describes how such an ecological catastrophe would occur. It also argues that the assertion of Indigenous territorial rights is key to the conservation of Amazonian biodiversity. The account unfolds against a background of conflict between Amazonia’s Indigenous peoples and the Brazilian State. In so doing, it brings to life the realities of frontier violence involving both land conflict and the unrestrained behaviors of individuals living outside the institutional constraints of law. Such violence complicates the execution of field research in the region and contributes to its gathering ecological crisis.

Decision-Making Method of Autonomous Vehicles in Urban Environments Considering Traffic Laws

In order to improve the efficiency and safety of autonomous vehicles’ decision-making process in complex urban scenarios, a decision-making method for hierarchical processing of static traffic law information and dynamic traffic participant information is proposed in this paper. In the decision-making method, the candidate behavior set is constructed by extracting the element of traffic laws and fully considering the traffic laws constraints to ensure the legality and effectiveness of the decision-making algorithm. Besides, four evaluation indicators and two-level entry threshold are designed to select the optimal driving behavior with the consideration of driving efficiency, ride safety and macro path requirement. The advantage of proposed method is that it avoids the problem of poor adaptability to traffic laws and regulations as the existing methods usually make decisions under the condition of mixed traffic laws and traffic participant information. A complete driving task simulation and analysis, including six typical urban traffic scenarios, is given under Matlab environment. The results show that the proposed decision-making method is able to make reasonable and feasible decisions and highly consistent with the actual driver’s decision-making behavior in complex urban scenarios, which verifies the effectiveness of the proposed method.

Weak coupling limit of U(1) lattice model in Fourier basis

The transfer-matrix of the U(1) lattice model is considered in the Fourier basis and in the weak coupling limit. The issues of Gauss law constraint and gauge invariant states are addressed in the Fourier basis. In particular, it is shown that in the strong coupling limit the gauge invariant Fourier states are effectively the finite size closed loop currents. In the weak coupling limit, however, the link-currents along periodic or infinite spatial directions find comparable roles as gauge invariant states. The subtleties related to the extreme weak coupling of the transfer-matrix in the Fourier basis are discussed. A careful analysis of the zero eigenvalues of the matrix in the quadratic action leads to a safe extraction of the diverging group volume in the limit $g\to 0$. By means of the very basic notions and tools of the lattice model, the spectrum at the weak coupling limit for any dimension and size of lattice is obtained analytically. The spectrum at the weak coupling limit corresponds to the expected one by the continuum model in the large lattice limit.

A Kinematic Modeling and Control Scheme for Different Robotic Endoscopes: A Rudimentary Research Prototype

In image-guided robotic surgery, there exist different endoscopes coupled either with specialized surgical robots (SSRs) or general industrial robots (GIRs). In general, SSRs mechanically respect the remote-center-of-motion (RCM) constraints with directly and explicitly controllable degrees-of-freedom (DoFs), whereas GIRs meet the constraints at the algorithmic level in an implicit manner, with a loss of direct control of some RCM DoFs. Conventionally, different robotic endoscopes are treated as different monolithic systems. Then, kinematic models and control schemes are separately established to automate different robotic endoscopes. This means that a similar analysis must be followed for each system, which is tedious and time-consuming. This letter introduces a modular method to analyze the individual kinematics of the robotic holder, the endoscope shaft and the surgical endoscope with RCM constraints explicitly handled. For achieving automation, the integrated kinematics of a generic robotic endoscope is determined by combining the kinematics of the modular elements. Considering that cameras are intrinsically embedded sensors, a visual servo control scheme applicable to different robotic endoscopes is formulated to incorporate four explicit (virtual) DoFs characterizing the RCM constraints in the control law. Simulations and experiments performed using three different robotic endoscopes validate the effectiveness and practicality of the kinematic modeling and control scheme for automatic field-of-view adjustment.

Event-triggered control for switched singular systems with asynchronous switching and state jumps

This work discusses the event-triggered control (ETC) issue for switched singular systems (SSS) with asynchronous switching and state jumps. Firstly, a modified consistency projector is presented to describe the transient state jumps at switching moments, which shows that the state jumps are caused by switching law and algebraic constraint. Then, a discontinuous multiple Lyapunov function is presented under the event-triggered state feedback control, and several sufficient conditions are derived to ensure that the closed-loop systems are regular, impluse-free and globally uniformly exponentially stable (GUES). Then, a Luenberger-like observer is constructed to estimate continuous and jumping states, some new sufficient conditions in terms of linear matrix inequalities (LMIs) are obtained by using matrix decoupling techniques under the observer-based ETC. Furthermore, a lower bound for the event-triggered time interval to exclude the Zeno phenomenon is given. Finally, two examples and an application are presented to demonstrate the validity of the results.

Made to be broken? A theory of regulatory governance and rule-breaking entrepreneurial action

Although regulatory institutions are said to enable and constrain entrepreneurial action, ventures frequently emerge with products, processes, and business models that skirt or defy these rules. We provide a theory of rule-breaking entrepreneurial action, focusing on why entrepreneurs are only sometimes constrained by law, regulation, and other formal constraints. In this, we attend to the dual roles of social context and subjective interpretation. Drawing on the sociology of law, we position regulatory rules within a system of governance, where public actors and legal intermediaries collectively construct the meaning of rule compliance and enact sanctions to enforce this interpretation. We leverage this to describe how enforcement imperfections and heterogeneous rule interpretations give rise to the possibility of ‘black market’ and ‘gray market’ entrepreneurial actions. In turn, we theorize how actors' knowledge and motivations can lead them to identify and exploit breakable rule conditions via the creation of new ventures. We illustrate our framework with examples from startups Zenefits, Square, and Aereo. Our framework changes the way we think about regulatory institutions and entrepreneurial action by presenting governance as a multilevel, social, and subjective process—such that some actors conform their entrepreneurial activities to established rules while others recognize and exploit breakable rule conditions.

BENJAMIN SACHS INTERVIEWED BY MARTHA MINOW

BENJAMIN SACHS INTERVIEWED BY MARTHA MINOW

A conceptual limbo of genocide: Russian rhetoric, mass atrocities in Ukraine, and the current definition’s limits

ABSTRACT The presence of multiple, semantically opposed usages of the term “genocide” not only poses a challenge for legally defining Russia’s atrocities in Ukraine, but also exemplifies the constraints of international law in dealing with mass civilian destruction in the twenty-first century. Indeed, despite widespread evidence of Russia’s genocidal behaviour, few scholars and lawyers believe it would be legally possible to prove Russia’s genocide in Ukraine. Nonetheless, given the powerful public image of genocide as the “crime of crimes,” political usage of the term by politicians, activists, and the general public has intensified since the beginning of Russia’s 2022 invasion with the hope of attracting global attention to (and ceasing) Russia’s atrocities. This paper provides some preliminary observations on how and why the concept of genocide has proven to be effective in fuelling civilian destruction rather than preventing it during the invasion. It first traces how Russia’s controversial, two-pronged rhetoric of genocide has evolved over the initial months of the invasion. It then examines Russia’s atrocities and the difficulties of classifying them as genocide.

Collective dynamics of capacity-constrained ride-pooling fleets

Ride-pooling (or ride-sharing) services combine trips of multiple customers along similar routes into a single vehicle. The collective dynamics of the fleet of ride-pooling vehicles fundamentally underlies the efficiency of these services. In simplified models, the common features of these dynamics give rise to scaling laws of the efficiency that are valid across a wide range of street networks and demand settings. However, it is unclear how constraints of the vehicle fleet impact such scaling laws. Here, we map the collective dynamics of capacity-constrained ride-pooling fleets to services with unlimited passenger capacity and identify an effective fleet size of available vehicles as the relevant scaling parameter characterizing the dynamics. Exploiting this mapping, we generalize the scaling laws of ride-pooling efficiency to capacity-constrained fleets. We approximate the scaling function with a queueing theoretical analysis of the dynamics in a minimal model system, thereby enabling mean-field predictions of required fleet sizes in more complex settings. These results may help to transfer insights from existing ride-pooling services to new settings or service locations.

CONSTRAINTS AND STRATEGIES OF ISSUING MUNICIPAL SUKUK IN INDONESIA

The purpose of this paper is to analyze the potential of Islamic municipal bonds in Indonesia focused on its constraint and strategy using Analytic Network Process (ANP). Methodology proceeded by literature research to construct a model and in-depth interview with practitioners and regulators both on government and sharia perspective to fully understand and develop an appropriate ANP Network. The experts are divided into two categories as direct relation and non-direct relation experts. The constraints are divided into five nodes, they are political risk, trust between stakeholders, lack of sharia knowledge, law constraint and risk of municipal loan. While the strategies contain of building trust, sharia education, comprehensive law basis, market strategy, and strategy of product innovation. Islamic municipal bonds may be developed by implementing comprehensive law basis as primary strategy to provide the need of law basis as main constraint. Both main constraint and strategy are agreed by all experts except BPK which is more concern in risk of municipal loan.

Prediction of optical solitons using an improved physics-informed neural network method with the conservation law constraint

In this work, based on the original physics-informed neural networks, we propose an improved physics-informed neural network method by combining the conservation laws. As one of the important integrable properties of nonlinear physical models, the conservation law can bring strong constraining force for the neural network to solve nonlinear physical models. Using this method, we study the standard nonlinear Schrödinger equation and predict various data-driven optical soliton solutions, including one-soliton, soliton molecules, two-soliton interaction, and rogue wave. In addition, from various exact solutions, we use the improved physics-informed neural network method to predict the dispersion and nonlinearity coefficients of the standard nonlinear Schrödinger equation based on the conservation law constraint. It turns out that the proposed method gives rise to the better results compared with the traditional physics-informed neural network method, and thus this method paves a way to simulate other physical models.

Agency, teleonomy and signal transduction in plant systems

AbstractPlants are the basis of nearly all food chains. The evolutionary response to inevitable predatory and other contingent hazards has provided plants with remarkable regenerative and plastic capabilities. Teleonomy has been characterized as purposive, adaptive and goal-directed behaviour. The evidence that plants are agents, that they act purposefully, is indicated by numerous behaviours, most notably plasticity. Through recurrent information exchange, growing roots construct a dynamic niche with bacterial and fungal symbionts. Purposeful shoot plasticity enables adaptive responses to abiotic and biotic hazards, with the goal of survival. Transgenerational inheritance furthers that goal for sibling survival. Teleonomic goals in shoot growth use proprioception to ensure successful tropic responses. Unlike animals that acquire energy biotically, nearly all plants are dependent solely on the physical environment. Convergent evolution is common and may result from the constraints of unchanging physical laws. Phenotypic plasticity initially provides a direction for evolutionary change. Our article indicates that there are features to evolutionary change in plants additional to those indicated by the modern synthesis and thus supports the extended evolutionary hypothesis.

Relaxed magnetohydrodynamics with ideal Ohm's law constraint

The gap between a recently developed dynamical version of relaxed magnetohydrodynamics (RxMHD) and ideal MHD (IMHD) is bridged by approximating the zero-resistivity ‘ideal’ Ohm's law (IOL) constraint using an augmented Lagrangian method borrowed from optimization theory. The augmentation combines a pointwise vector Lagrange multiplier method and global penalty function method and can be used either for iterative enforcement of the IOL to arbitrary accuracy, or for constructing a continuous sequence of magnetofluid dynamics models running between RxMHD (no IOL) and weak IMHD (IOL almost everywhere). This is illustrated by deriving dispersion relations for linear waves on an MHD equilibrium.

Application of conservation laws to the learning of physics-informed neural networks

We consider the modifications of a physics-informed neural network, based on conservation law constraint as the important feature of integrable physical models. This method implies introduction of the conservative properties of nonlinear physical systems into neural network to force qualitatively correctness of the solution during training. The conservation law constraint is put into neural network solver by adding the conserved quantity's residual to the loss function to train the neural network. We apply the modification on the one-dimensional nonlinear Schrӧdinger equation as the example of integrable system. In our experiments, Continuity Planes method was implemented to add the conservation constraint to the loss function. For further generalization on high dimension systems, we also considered Monte Carlo approach to control the conserved quantity through sum over interior points of the domain. The results obtained demonstrate an increase in the accuracy of prediction compared to conventional training for several cases.

Perturbative F-theory 10-brane and M-theory 5-brane

The exceptional symmetry is realized perturbatively in F-theory which is the manifest U-duality theory. The SO(5) U-duality symmetry acts on both the 16 space-time coordinates and the 10 worldvolume coordinates. Closure of the Virasoro algebra requires the Gauss law constraints on the worldvolume. This set of current algebras describes a F-theory 10-brane. The SO(5) duality symmetry is enlarged to the SO(6) symmetry in the Lagrangian formulation. We propose actions of the F-theory 10-brane with SO(5) and SO(6) symmetries. The gauge fields of the latter action are coset elements of SO(6)/SO(6; ℂ) which include both the SO(5)/SO(5; ℂ) spacetime backgrounds and the worldvolume backgrounds. The SO(5) current algebra obtained from the Pasti-Sorokin-Tonin M5-brane Lagrangian leads to the theory behind M-theory, namely F-theory. We also propose an action of the perturbative M-theory 5-brane obtained by sectioning the worldvolume of the F-theory 10-brane.