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This paper aims to present a pipeline to progressively deal with the online external parameter calibration and estimator initialization of the Stereo-inertial measurement unit (IMU) system, which does not require any prior information and is suitable for system initialization in a variety of environments.

Before calibration and initialization, a modified stereo tracking method is adopted to obtain a motion pose, which provides prerequisites for the next three steps. Firstly, the authors align the pose obtained with the IMU measurements and linearly calculate the rough external parameters and gravity vector to provide initial values for the next optimization. Secondly, the authors fix the pose obtained by the vision and restore the external and inertial parameters of the system by optimizing the pre-integration of the IMU. Thirdly, the result of the previous step is used to perform visual-inertial joint optimization to further refine the external and inertial parameters.

The results of public data set experiments and actual experiments show that this method has better accuracy and robustness compared with the state of-the-art.

This method improves the accuracy of external parameters calibration and initialization and prevents the system from falling into a local minimum. Different from the traditional method of solving inertial navigation parameters separately, in this paper, all inertial navigation parameters are solved at one time, and the results of the previous step are used as the seed for the next optimization, and gradually solve the external inertial navigation parameters from coarse to fine, which avoids falling into a local minimum, reduces the number of iterations during optimization and improves the efficiency of the system.

Contact problems are among the most difficult ones in mechanics. Due to its practical importance, the problem has been receiving extensive research work over the years. The finite element method has been widely used to solve contact problems with various grades of complexity. Great progress has been made on both theoretical studies and engineering applications. This paper reviews some of the main developments in contact theories and finite element solution techniques for static contact problems. Classical and variational formulations of the problem are first given and then finite element solution techniques are reviewed. Available constraint methods, friction laws and contact searching algorithms are also briefly described. At the end of the paper, a bibliography is included, listing about seven hundred papers which are related to static contact problems and have been published in various journals and conference proceedings from 1976.

To address the impact of adding insulated plate extensions at the entrance of an isoflux vertical parallel‐plate channel on the thermal performances of natural convection in air for these systems.

The model relies on the full elliptic conservation equations which are solved numerically in a composite three‐part computational domain by means of the finite‐volume method.

Results are reported in terms of wall temperatures, induced mass flow rates, as well as velocity and temperature profiles of the air for various thermal and geometric parameters. The wall temperatures increase when the extensions are appended at the inlet of the channel. Wall temperature profiles strongly depend on the Rayleigh number and the dependence of the heated channel aspect ratio is weaker than the extension ratio. Velocity and temperature profiles modify inside the heated channel due to the thermal development. In addition, correlation equations for main engineering quantities, such as the induced mass flow rate, average Nusselt number and dimensionless maximum wall temperature in terms of the channel Rayleigh number, channel aspect ratio and extension ratio are presented.

The investigation has been carried out in the following ranges: 10³‐10⁵ for the Rayleigh number, 5.0‐15.0 for the channel aspect ratio and 1.0‐5.0 for the extension ratio. The hypotheses on which the present analysis is based are: two‐dimensional, laminar and steady‐state flow, constant thermophysical properties with the Boussinesq approximation.

Thermal design of heating systems in manufacturing processes, evaluation of heat convective coefficients and maximum attained wall temperatures.

Evaluation of the thermal and velocity fields and correlation equations for the Nusselt number and maximum dimensionless temperatures in natural convection in air for vertical channels. The paper is useful to thermal designers.

The health workforce of the 21st century has enormous challenges; health professionals need to be both experts in their field and equipped with leadership and managerial skills. These skills are not part of the regular curriculum, so specific programs bridging this gap are required. Since 2001, FAIMER®, with eight centers across the globe, has worked to create health professions education leaders through transformational learning experiences, developing a global community of practice encompassing over 40 countries. We describe the design, implementation, evaluation, and evolution of the leadership and management curriculum component of the global Institute over 15 years. The curriculum is developed and updated through practices that keep faculty and fellows connected, aligned, and learning together. The article highlights the unique features, challenges faced, and sustainability issues. With a robust mixed methods evaluation, there are substantial reasons to believe that the model works, is adaptable and replicable to meet local needs. The program is playing an important role of answering the call for training positive, strengths-based, collaborative leaders who are socially accountable and embrace the challenges for high quality equitable health care around the globe

Whilst Hong Kong is suffering from a limited supply of developable land in its major urban areas, some open spaces are frequently criticized as inconvenient for users, consequently leading to an ineffective use pattern. How to enhance the performance of open space is therefore a critical issue faced by city planners. As the conventional accessibility model, which is mainly described with respect to maximum walking distance or service radius, is inadequate to give an account of the issue, this paper accordingly indicates an alternative approach and seeks an explanation from the urban configuration and the way it conditions pedestrian movement pattern. Through investigating the relationship between urban configuration, pedestrian movement and accessibility and use of open spaces based on the Wanchai District of Hong Kong, which particularly epitomizes various urban grids that may have different consequences on the utilization of open space, this study aims to examine whether there is a consistent relationship existing in different spatial grids or whether the relationship varies from different layout patterns. It is hoped that the findings can be employed to improve the performance of open spaces in the urban areas of Hong Kong, in addition to other similar urban environment.

The attributes that influence the selection of applicants and the relevant crediting decisions are naturally distinguished by interactions and interdependencies. A new method of possibilistic discrimination analysis (MPDA) was developed for the second stage to address this phenomenon. The method generates positive and negative discrimination measures for each alternative applicant in relation to a particular attribute. The obtained discrimination pair reflects the interaction of attributes and represents intuitionistic fuzzy numbers (IFNs). For the aggregation of applicant's discrimination intuitionistic fuzzy assessments (with respect to attributes), new intuitionistic aggregation operators, such as AsP-IFOWA and AsP-IFOWG, are defined and studied. The new operators are certain extensions of the well-known Choquet integral and Yager OWA operators. The extensions, in contrast to the Choquet aggregation, take into account all possible interactions of the attributes by introducing associated probabilities of a fuzzy measure.

For optimal planning of investments distribution and decreasing of credit risks, it is crucial to have selected projects ranked within deeply detailed investment model. To achieve this, a new approach developed in this article involves three stages. The first stage is to reduce a possibly large number of applicants for credit, and here, the method of expertons is used. At the second stage, a model of improved decisions is built, which reduces the risks of decision making. In this model, as it is in multi-attribute decision-making (MADM) + multi-objective decision-making (MODM), expert evaluations are presented in terms of utility, gain, and more. At the third stage, the authors construct the bi-criteria discrete intuitionistic fuzzy optimization problem for making the most profitable investment portfolio with new criterion: 1) Maximization of total ranking index of selected applicants' group and classical criterion and 2) Maximization of total profit of selected applicants' group.

The example gives the Pareto fronts obtained by both new operators, the Choquet integral and Yager OWA operators also well-known TOPSIS approach, for selecting applicants and awarding credits. For a fuzzy measure, the possibility measure defined on the expert evaluations of attributes is taken.

The comparative analysis identifies the applicants who will receive the funding sequentially based on crediting resources and their requirements. It has become apparent that the use of the new criterion has given more credibility to applicants in making optimal credit decisions in the environment of extended new operators, where the phenomenon of interaction of all attributes was also taken into account.

Fundamental analysis is aimed at assessing the intrinsic value of companies based on publicly available accounting information. Thus, the main purpose of fundamental analysis research should be identifying the main determinants of value, establishing empirical relations between them and fundamental accounting variables, and finally, predicting the future behavior of such variables to estimate the value of the firm. Traditional fundamental analysis ignores the existence of some intangible assets, such as intellectual capital, that are currently considered as the main determinants of value. Human capital is an essential component of intellectual capital. This paper provides evidence on the extent to which the quality of human resources is related to the value of accounting variables that are used in fundamental analysis due to their perceived usefulness as proxies for investors' expectations on the firm's future profitability and growth in both, earnings and shareholders' equity.

This paper aims to propose a method to solve the problem of localization and mapping of a two-wheeled inverted pendulum (TWIP) robot on the ground using the Stereo–inertial measurement unit (IMU) system. This method reparametrizes the pose according to the motion characteristics of TWIP and considers the impact of uneven ground on vision and IMU, which is more adaptable to the real environment.

When TWIP moves, it is constrained by the ground and swings back and forth to maintain balance. Therefore, the authors parameterize the robot pose as SE(2) pose plus pitch according to the motion characteristics of TWIP. However, the authors do not omit disturbances in other directions but perform error modeling, which is integrated into the visual constraints and IMU pre-integration constraints as an error term. Finally, the authors analyze the influence of the error term on the vision and IMU constraints during the optimization process. Compared to traditional algorithms, the algorithm is simpler and better adapt to the real environment.

The results of indoor and outdoor experiments show that, for the TWIP robot, the method has better positioning accuracy and robustness compared with the state-of-the-art.

The algorithm in this paper is proposed for the localization and mapping of a TWIP robot. Different from the traditional positioning method on SE(3), this paper parameterizes the robot pose as SE(2) pose plus pitch according to the motion of TWIP and the motion disturbances in other directions are integrated into visual constraints and IMU pre-integration constraints as error terms, which simplifies the optimization parameters, better adapts to the real environment and improves the accuracy of positioning.

This issue is a selected bibliography covering the subject of leadership.

The purpose of this paper is the dynamic analysis of the coupled rotation and vibration motion of a system containing a central rigid body to which is attached a flexible beam.

The methodology includes the Lagrange’s formulation by using the extended Hamilton’s Principle in conjunction with the assumed modes method to describe the system of equations by ordinary differential equations. The first unconstrained mode of vibration was considered as the solution for the transversal displacement. Such mode emerges as the eigenvalue problem solution associated to the dynamics of the system. The control strategy adopted is a nonlinear analogy of the linear quadratic regulator problem as the Riccati equation is solved at every integration step during the numerical solutions. This strategy is known as state-dependent Riccati equation.

By means of computational simulations, it was found the relation between controlled motion and inertia ratio.

This work is limited to planar case and fixed hub.

Practical implications of this work realize the design of lighter yet dexterous structures.

The contribution of this paper is the position and vibration control of a flexible beam accounting for nonlinearity effects and the fact that the structure to where it is clamped has a comparable inertia.