Joint inversion of magnetotelluric and fullwaveform seismic data based on alternating cross-gradient structural constraints

Magnetotelluric(MT)inversion and seismic inversion are important methods for the interpretation of subsurface exploration data,but separate inversion of MT and seismic produces ambiguous and non-unique results due to various factors.In order to achieve accurate results,the authors propose a joint inversion method of two-dimensional MT and seismic data in the frequency domain.The finite element method is used for numerical simulation of electromagnetic data in the forward modelling,and the Gauss-Newton method is used for the inversion.The 9-point-finite-difference method is used to solve the seismic wave field in the acoustic wave equation,and the inverse problem of seismic data is solved by full waveform inversion with a conjugate gradient,a simple and fast method.Cross gradient functions are used to provide constraint structure between resistivity and velocity parameters to carry out the joint inversion.The joint inversion algorithm is tested by double-rectangular model synthesis data,and the accuracy of the algorithm is verified.The results show that the joint inversion results are better than those from separate inversion.The algorithm is applied to a geophysical model of a metalliferous deposit in Jinchuan and is compared with the separate inversion results.It shows that the results obtained with joint inversion are much closer to the real model.

Structural constraints and its countermeasures to contiguous poor areas with particular difficulties: An case study on southern Shaanxi immigration project

Immigration relocation of the poor in rural areas is an effective targeted measure to help people out of poverty in the new normal. The structural constraints lie in the heavy pressure of land resources and environmental carrying capacity, high cost of immigration settlement and delayed counterpart funds, insufficient industrial support and difficulty in living-making. To realize the goal of targeted poverty alleviation, it demands determination and capability from the policy designer, as well the social basis. The effect imposed by the structural constraints to implementation of such policy should be paid adequate attention by public sectors. It is supposed to change the guiding direction of the policy timely and to relieve financial burden of immigration settlement and resource environmental bearing capacity through mechanism of joint efforts from internal and more external support.

Structural Constraints on Legal Change:Chinese Lawyers in the Interaction between the State,the Market and Society

Studies on the sources of change in the Chinese legal system are usually based on the statist epistemology, i.e. the will of the state directs and even determines all aspects of change in the legal system. Although this epistemology can partially explain the re-creation of the Chinese legal system during the earlier period of reform and opening up, it fails to provide a comprehensive picture of the present complex situation. Taking as an example the changes in the Chinese legal profession during reform and opening up, this study employs quantitative data and empirical methods to explore the multiple dynamic impacts of the state, the market and society on the Chinese legal system. The study also proposes a theoretical framework of ＂structural constraints＂ on legal change. Since reform and opening up, the Chinese legal system has undergone a transition from state dominance to multi-agent interactions between the state, the market, society, and the legal system itself.

Detecting Designated Building Areas From Remote Sensing Images Using Hierarchical Structural Constraints

Automatic detection of a designated building area(DBA)is a research hotspot in the field of target detection using remote sensing images.Target detection is urgently needed for tasks such as illegal building monitoring,dynamic land use monitoring,antiterrorism efforts,and military reconnaissance.The existing detection methods generally have low efficiency and poor detection accuracy due to the large size and complexity of remote sensing scenes.To address the problems of the current detection methods,this paper presents a DBA detection method that uses hierarchical structural constraints in remote sensing images.Our method was conducted in two main stages.(1)During keypoint generation,we proposed a screening method based on structural pattern descriptors.The local pattern feature of the initial keypoints was described by a multilevel local pattern histogram(MLPH)feature;then,we used one-class support vector machine(OC-SVM)merely to screen those building attribute keypoints.(2)To match the screened keypoints,we proposed a reliable DBA detection method based on matching the local structural similarities of the screened keypoints.We achieved precise keypoint matching by calculating the similarities of the local skeletal structures in the neighboring areas around the roughly matched keypoints to achieve DBA detection.We tested the proposed method on building area sets of different types and at different time phases.The experimental results show that the proposed method is both highly accurate and computationally efficient.

Developing rigid constraint for the estimation of pose and structure from a single image

Pose and structure estimation from a single image is a fundamental problem in machine vision and multiple sensor fusion and integration. In this paper we propose using rigid constraints described in different coordinate frames to iteratively estimate structural and camera pose parameters. Using geometric properties of reflected correspondences we put forward a new concept, the reflected pole of a rigid transformation. The reflected pole represents a general analysis of transformations that can be applied to both 2D and 3D transformations. We demonstrate how the concept is applied to calibration by proposing an iterative method to estimate the structural parameters of objects. The method is based on a coarse-to-fine strategy in which initial estimation is obtained through a classical linear algorithm which is then refined by iteration. For a comparative study of performance, we also implemented an extended motion estimation algorithm (from 2D-2D to 3D-2D case) based on epipolar geometry.

A Study on the Participation of Foreign Students in Local Cultural and Folk Activities in Wenzhou

The number of foreign students studying in Wenzhou, China has increased dramatically as a result of the Belt and Road Initiative. Learning the motivations and leisure constraints of foreign students' participation in local cultural and folk activities in Wenzhou is beneficial to promoting cultural adaptation, strengthening Chinese cultural self-confidence, and improving Wenzhou's international image. Based on the hierarchical model of leisure constraints (personal constraints, interpersonal constraints, and structural constraints), this study has tended to focus on the leisure constraints for foreign students participating in local folk and cultural activities in Wenzhou. A total of seven participants were included in the analysis.

Determinants Analysis on Adolescents

Determinants analysis is a pretty recent approach in social research and policy reviews, so that one cannot speak about generally/largely agreed definition of concepts yet. The paper endeavors to propose a framework for analyzing the factors that, at structural, proximity, and individual levels, impede the realization of adolescents＇ rights to education, health, and protection. This framework was first conceived for the purpose of being used within a study on the state of adolescents in Romania, commissioned by the United Nations International Children＇s Emergency Fund （UNICEF） Romania and carried out by the Centre for Urban and Regional Sociology and Institute for Educational Sciences, which fmally used a slightly different approach, in a view to observe the determinants＇ framework already in use by UNICEF. The proposed framework is based on the structure-agency approach embraced by several international youth researches, which argue that individual actions and behaviors are in most cases the results of an interplay between structural constraints （institutional settings and rules） and individual agency. This approach is important for a determinants＇ analysis because it requires due consideration of individual features as well while discussing the role of social determinants in setting choice constraints and shaping pathways for adolescents＇ achievement of their rights. It is also important when approaching vulnerable adolescents, since vulnerability is often associated not only with structural and/or proximity determinants, but also with individual features.

OUT-OF-PLANE COMPRESSIVE PROPERTIES OF HEXAGONAL PAPER HONEYCOMBS

The compressive behaviour of paper honeycombs is studied by means of an experimental analysis. Experiment results show how geometry aspects of hexagonal paper honeycombs, e.g. the height of paper honeycomb, the thickness and length of honeycomb cell-wall, the drawing ratio of hexagonal honeycomb, affect the compressive properties of the paper honeycombs. It is in good agreement with the theory model. The constraint factor K of the critical buckling stress is mainly determined by the length of honeycomb cell-wail. It can be described as K=1.54 for B type paper honeycombs and K=3.32 for D type paper honeycombs. The plateau stress is the power exponent function of the thickness to length ratio of honeycomb cell-wall, and the experiment results show that the constant is 13.2 and the power exponent is 1.77. The research results can be used to characterize and improve efficiently the compressive properties of paper honeycombs.

Stiffeners layout design of thin-walled structures with constraints on multi-fastener joint loads

The purpose of this paper is to present an extended topology optimization method for the stiffeners layout design of aircraft assembled structures. Multi-fastener joint loads and manufacturing constraints are considered simultaneously. On one hand, the joint loads are calculated and constrained within a limited value to avoid the failure of fasteners. On the other hand, the manufacturing constraints of the material distribution in the machining directions of stiffeners are implemented by an improved piecewise interpolation based on a beveled cut-surface. It is proven that the objective function is strictly continuous and differentiable with respect to the piecewise interpolation. The effects of the extended method with two different constraints are highlighted by typical numerical examples. Compared with the standard topology optimization, the final designs have clearly shown the layout of stiffeners and the joint loads have been perfectly constrained to a satisfying level.

A noninteracting control strategy for the robust output synchronization of linear heterogeneous networks

This paper deals with the problem of robust output synchronization for heterogeneous multi-agent systems. First, a new synchronization approach is presented to synchronize the outputs of heterogeneous agents. Based on noninteracting control techniques, a method is derived for homogenizing the input-output behavior of every agent. Hence, applying the same reference input signal to every agent leads to synchronization. Furthermore, a strategy for increasing the robustness of the synchronization process against exogenous disturbances is presented, which leads to a structurally constrained optimization problem. However, by a convenient reformulation of the problem, well established tools from robust control theory can be used. Moreover, it is shown that this procedure allows to separate the robustness issue from the synchronization task. The effectiveness of the approach is illustrated by a robust output synchronization example for a heterogeneous aircraft fleet.

Progressive events in supervisory control and compositional verification

This paper investigates some limitations of the nonblocking property when used for supervisor synthesis in discrete event systems. It is shown that there are cases where synthesis with the nonblocking property gives undesired results. To address such cases, the paper introduces progressive events as a means to specify more precisely how a synthesised supervisor should complete its tasks. The nonblocking property is modified to take progressive events into account, and appropriate methods for verification and synthesis are proposed. Experiments show that progressive events can be used in the analysis of industrial-scale systems, and can expose issues that remain undetected by standard nonblocking verification.