Research on the risk-evaluation model of power transmission and transformation projects based on multilevel fuzzy-thought weighting for cloud-model improvement

The risk evaluation of power transmission and transformation projects is a complex and comprehensive evaluation process influenced by many factors and involves many indicators.In order to solve the uncertainty and fuzziness problems in the process of the multilevel fuzzy risk evaluation of power transmission and transformation projects,this paper introduces the cloud theory,which is specialized in the study of uncertainty problems and constructs the multilevel fuzzy comprehensive risk-evaluation model of power transmission and transformation projects based on the improved multilevel fuzzy-thought weighting based on the cloud model.Finally,the risk of the Beijing 220-kV Tangyu power transmission and transformation project is evaluated and the feasibility of the evaluation model is verified.The results of the evaluation and the evaluation layer cloud model are combined with MATLAB simulation to show that the risk level of the project is between large risk and general risk.

Prediction model for cost data of a power transmission and transformation project based on Pearson correlation coefficient-IPSO-ELM

In view of the difficulty in predicting the cost data of power transmission and transformation projects at present,a method based on Pearson correlation coefficient-improved particle swarm optimization(IPSO)-extreme learning machine(ELM)is proposed.In this paper,the Pearson correlation coefficient is used to screen out the main influencing factors as the input-independent variables of the ELM algorithm and IPSO based on a ladder-structure coding method is used to optimize the number of hidden-layer nodes,input weights and bias values of the ELM.Therefore,the prediction model for the cost data of power transmission and transformation projects based on the Pearson correlation coefficient-IPSO-ELM algorithm is constructed.Through the analysis of calculation examples,it is proved that the prediction accuracy of the proposed method is higher than that of other algorithms,which verifies the effectiveness of the model.

Verifiable Secret Sharing Scheme Based on Certain Projective Transformation

The main purpose of verifiable secret sharing scheme is to solve the honesty problem of participants. In this paper, the concept of nonzero k-submatrix and theresidual vector of system of hyperplane intersecting line equations is proposed. Based on certain projective transformations in projective space, a verifiable (t, n)-threshold secret sharing scheme is designed by using the structure of solutions of linear equations and the difficulty of solving discrete logarithm problems. The results show that this scheme can verify the correctness of the subkey provided by each participant before the reconstruction of the master key, and can effectively identify the fraudster. The fraudster can only cheat by guessing and the probability of success is only 1/p. The design of the scheme is exquisite and the calculation complexity is small. Each participant only needs to hold a subkey, which is convenient for management and use. The analysis shows that the scheme in this paper meets the security requirements and rules of secret sharing, and it is a computationally secure and effective scheme with good practical value.

Optimal Positioning Strategy for Multi-Camera Zooming Drones

In the context of multiple-target tracking and surveillance applications,this paper investigates the challenge of determining the optimal positioning of a single autonomous aerial vehicle or agent equipped with multiple independently-steerable zooming cameras to effectively monitor a set of targets of interest.Each camera is dedicated to tracking a specific target or cluster of targets.The key innovation of this study,in comparison to existing approaches,lies in incorporating the zooming factor for the onboard cameras into the optimization problem.This enhancement offers greater flexibility during mission execution by allowing the autonomous agent to adjust the focal lengths of the onboard cameras,in exchange for varying real-world distances to the corresponding targets,thereby providing additional degrees of freedom to the optimization problem.The proposed optimization framework aims to strike a balance among various factors,including distance to the targets,verticality of viewpoints,and the required focal length for each camera.The primary focus of this paper is to establish the theoretical groundwork for addressing the non-convex nature of the optimization problem arising from these considerations.To this end,we develop an original convex approximation strategy.The paper also includes simulations of diverse scenarios,featuring varying numbers of onboard tracking cameras and target motion profiles,to validate the effectiveness of the proposed approach.

Geometric Computing Based on Computerized Descriptive Geometric

Computer-aided Design （CAD）, video games and other computer graphic related technology evolves substantial processing to geometric elements. A novel geometric computing method is proposed with the integration of descriptive geometry, math and computer algorithm. Firstly, geometric elements in general position are transformed to a special position in new coordinate system. Then a 3D problem is projected to new coordinate planes. Finally, according to 2D/3D correspondence principle in descriptive geometry, the solution is constructed computerized drawing process with ruler and compasses. In order to make this method a regular operation, a two-level pattern is established. Basic Layer is a set algebraic packaged function including about ten Primary Geometric Functions （PGF） and one projection transformation. In Application Layer, a proper coordinate is established and a sequence of PGFs is sought for to get the final results. Examples illustrate the advantages of our method on dimension reduction, regulatory and visual computing and robustness.

Non-Euclidean Geometry and Regulated Characteristics of Limited Capacity Power Supply

The restriction of load power, two-valued regulation characteristic, and interference of several loads are observed in power supply systems with a limited capacity of voltage sources. In this paper, the definition of regime in an invariant form through different parameters, of changes of transformation ratio and voltage load is grounded for these circuits with two loads. The approach for interpretation of changes or ＂kinematics＂ of load regime is presented by using the conformal and hyperbolic plane. To simplify the task and reveal the basic moments of influence of the limited source power, the static regulation characteristics and idealized models of voltage converters are considered. Geometrical interpretation of a simplified model of multichannel power supply system allows basing the definition of operating regime parameters. Results can be useful for electric circuit theory education and for voltage coordinated control of given loads. Non-Euclidean geometry is a new mathematical apparatus in the electric circuit theory, adequately interprets ＂kinematics＂ of circuit, and provides a validation for the introduction and definition of the proposed concepts. From the methodological point, the presented approach is applied for a long time in other scientific domains, as mechanics and biology.

Progress of research on urban-rural transformation and rural development in China in the past decade and future prospects

Urban-rural transformation and rural development are issues at the forefront of research on the topic of the urban-rural relationship in the field of geography, as well as important practical problems facing China＇s new urbanization and overall planning of urban and rural development. The Center for Regional Agricultural and Rural Development, part of the Institute of Geographic Sciences and Natural Resources Research under the Chinese Academy of Sciences, was established in 2005. The Center has laid solid foundations for integrating research in the areas of agricultural geography and rural development in China over the past decade. The paper aims to review the major achievements in rural geographical research in China during the past decade, analyze innovative developments in relevant theories and methods, and suggest prospects and countermeasures for promoting comprehensive studies of urban-rural transformation and rural geography. The research shows that innovative achievements have been made in rural geography studies of China in the past decade as major national policy development, outputs of result and decision making support; new breakthroughs have been achieved in such major research projects as geographical integrated theory, land remediation projects and technology demonstration projects, new urbanization and urban-rural integration; significant progress has been made in actively expanding the frontiers of rural geography and pushing forward theoretical innovations in land and resource projects; and, with China＇s development goals of building a moderately prosperous society in all respects and achieving modernization in mind, future innovative developments in agricultural and rural geography should aim to make research more strategic, systematic, scientific and security-oriented, with attention given to promoting systematic scientific research on international cooperation and global rural geography.

Algebraic Conditions for Classifying the Positional Relationships Between TwoConies and Their Applications

In many fields of computer science such as computer animation, computergraphics, computer aided geometric design and robotics, it is a common problem to detect thepositional relationships of several entities. Based on generalized characteristic polynomials andprojective transformations, algebraic conditions are derived for detecting the various positionalrelationships between two planar conies, namely, outer separation, exterior contact, intersection,interior contact and inclusion. Then the results are applied to detecting the positionalrelationships between a cylinder (or a cone) and a quadric. The criteria is very effective andeasier to use than other known methods.

Range Information Propagation Transform

A novel method of model-based object recognition is presented in this paper. Its novelty stems from the fact that the gray level image captured by a camera is merged with sparse range information in an active manner. By using a projective transform,which is determined by the sparse range data, features (e.g. edge points) related to a single planar surface patch or figure in the scene can be assigned with their corresponding range values respectively. As a result, the shape of the very planar patch or figure can be recovered and various kinds of description in the Euclidean space can be calculated. Based on these descriptions values, the hypothesis about the identification of the object and its pose in space can be obtained with a high probability of success, and a high efficiency of hypothesis- verification process can be expected. Another advantage of this method is that the edge detection process can be navigated to the proper location hinted by the sparse range image. In consequence edge features can be extracted even in the regions with low contrast. In this paper the principle of range information propagation transform (RIPT) is explained, and some implementation issues, such as the algorithms using calibrated or uncalibrated gray level image for object recognition, are discussed. The preliminary experimental results are presented to indicate the effectiveness and efficiency of the proposed method.

The Closed Orbits of a Class of Cubic Vector Fields in R^(3)

In this paper,we investigate the isolated closed orbits of two types of cubic vector fields in R^3 by using the idea of central projection transformation,which sets up a bridge connecting the vector field X(x)in R^3 with the planar vector fields.We have proved that the cubic vector field in R^3 can have two isolated closed orbits or one closed orbit on the invariant cone.As an application of this result,we have shown that a class of 3-dimensional cubic system has at least 10 isolated closed orbits located on 5 invariant cones,and another type of 3-dimensional cubic system has at least 26 isolated closed orbits located on 13 invariant cones or 26 invariant cones.