Input Link Research Articles

Strategic Cost Control and Management in Corporations

In today's new situation and new state of affairs, the modernization of society with the gradual development of information technology, with people's consumption level, medical level of life gradually improve the pursuit of culture is more and more diversified, information is more and more prosperous. Various industries and fields have begun a new class of more intense competition, they are not limited to business competition, but need to go from the root of the reasonable integrated planning, in order to put more favorable funds into the follow-up input and important links, so in the current situation to form a good enterprise cost management control is critical to determine the development of the enterprise. This paper will discuss the importance of enterprise cost management control through the four different industries of enterprises according to their characteristics, and provide a certain exploration program, expound the relevant theories of enterprise cost management control, and combined with the status quo to give the basic measures.

Sensitivity of AERMOD (V21112) RLINEXT dispersion model outputs by source type to variability in single noise barrier height and separation distance

The U.S. Environmental Protection Agency (USEPA) introduced the RLINEXT modeling feature in the latest versions of AERMOD (since version v21112) to predict traffic-induced pollutant concentration when noise barriers are present. The research presented in this paper explores the impacts of noise barrier characteristics on AERMOD-predicted concentrations. The research finds that because AERMOD can currently only attach one barrier to each road side, and because that barrier only impacts the source to which it is attached, it is also important to split links so that they properly pair with barriers. Given the sensitivity of AERMOD-predicted concentrations to barrier characteristics (i.e., barrier heights and distances to roadway), the research also concludes that barriers must be appropriately matched with input links. This study investigated the sensitivity of CO concentration predicted by the latest AERMOD under various noise barrier conditions (barrier heights and distances between road and barrier) and meteorological conditions (wind directions and wind speeds). The results indicate that ground-level concentration of downwind receptors decreases with increased barrier heights, and that distant barriers have less of an impact on predicted concentrations. This study also explored the impact of noise barrier on both horizontal and vertical concentration profiles, indicating that concentrations rise behind the barrier as plumes are predicted to loft over the barrier. The sensitivity analysis associated with splitting roadway links to match with barriers indicated an impact on predicted concentration for certain receptors of up to 10%, but the overall the impact on maximum concentrations was marginal.

Total Unimodularity and Strongly Polynomial Solvability of Constrained Minimum Input Selections for Structural Controllability: An LP-Based Method

This paper investigates several cost-sparsity induced optimal input selection problems for structured systems. Given an autonomous system and a prescribed set of input links, where each input link has a non-negative cost, the problems include selecting the minimum cost of input links and selecting the input links with the smallest possible cost while bounding their cardinality to achieve system structural controllability. Current studies show that in the dedicated input case (i.e., each input can actuate only one state variable), the former problem is polynomially solvable by some graph-theoretic algorithms, while the general nontrivial constrained case is largely unexplored. We show that these problems can be formulated as equivalent integer linear programming (ILP) problems. Subject to the 'source strongly-connected component grouped input constraint', which contains the dedicated input one as a special case, we demonstrate that the constraint matrices of these ILPs are <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">totally unimodular</i> . This property allows us to solve these ILPs efficiently via their linear programming (LP) relaxations, leading to a unifying algebraic method for these problems with polynomial time complexity. We further show that these problems can be solved in strongly polynomial time, independent of the size of the costs and cardinality bounds. Finally, we provide an example to illustrate the power of the proposed method.

Stab-FD: A cooperative and adaptive failure detector for wide area networks

Failure detectors (FDs) are a fundamental abstraction that plays a central role in the design of distributed systems. FDs are distributed oracles that provide processes with unreliable information about process failures, often in the form of a list of trusted or suspected process identities. In this article, we propose a timer-based FD which assesses the quality of its input links, and exchanges its local estimations with other nodes. Nodes use this information to adjust their timers dynamically. Capturing the variations in the quality of each link reduces the number of false suspicions without degrading failure detection time. We present experiments on a dataset of real traces collected on PlanetLab, and compare our approach to well-known state-of-the-art algorithms. Our results show that our new algorithms yield a good trade-off in terms of failure detection speed and accuracy in real scenarios.

IrisVSA: Infinite-rotation infinite-stiffness Variable Stiffness Actuator towards physical human–robot-interaction

In Human–Robot-Collaboration applications, variable stiffness actuators provide an attractive actuation solution due to their well-established capabilities in ensuring accuracy and safety. Although, several existing VSAs have achieved an infinite-range of stiffness, those are generally relatively bulky, incapable of attaining an infinite-range of rotation, and their stiffness adjustment rate is rather slow. In this paper, we introduce a new infinite-rotation infinite-stiffness Variable Stiffness Actuator (irisVSA). The novelty of this actuator lies in its design topology, where two long-armed torsional springs are mounted on the output link and connected to the input link via a Force Contact Point (FCP). The variation in stiffness is realized by altering the relative distance from the FCP to the joint rotation center (effective arm). This unique topology offers a wide range of stiffness ranging from transparency (0 stiffness) to physically rigid. Moreover, the rate of stiffness adjustment is considerably fast (0.7 sec) through the utilization of a hypocycloid gear train. The working principle, design, prototyping, and characterization process for the irisVSA are detailed here. A Nonlinear Proportional–Integral–Derivative Controller is proposed to ensure the system’s accuracy. The safety of the actuator was evaluated by subjecting it to both impact force criterion experiments as well as Head Injury Criterion.

Sensitivity analysis of shock distributions in the world economy.

With the ever increasing interconnectedness among countries and industries, globalization has empowered economies and promoted international trade, capital flow and labor mobility, leading to improved products and services. However, the growing interdependence has also propelled an inherent reliance on joint cooperation which has considerably influenced the complexity of global value chains (GVCs). This plays a significant role in policy decisions, raising questions about trade risks that originate from such interdependence. In this paper, we study the impact of network linkage disturbances on the output supply and input demand of countries. We model the network interconnectedness of countries according to the latest 2016 release of the World Input-Output Database (WIOD) that includes data tables for the period 2000-2014 covering 43 countries as well as a model for the Rest of the World (ROW). We assess the shock distributions across the world economy by quantifying the changes in the network linkages using sensitivity analysis. Our contribution is in the definition of a shock tensor with the purpose of evaluating the impact of link sensitivity. The shock tensor is a straightforward yet comprehensive tool that allows us to obtain ample results at various levels of granularity when combining it with aggregation operators. Our study introduces a novel methodology that enables us to acquire input and output link sensitivities for all country pairings when an economic shock initiates or concludes within a country of interest. This innovative approach also facilitates the analysis of evolving trends in these link sensitivities, providing a comprehensive understanding of the dynamics of shock propagation across the global network. Taking advantage of the time-series nature of the WIOD, our results reveal illustrative visualizations and quantative measures that characterize patterns of shock distribution and relationships among countries throughout the period from 2000 to 2014. Our methodology and results not only uncover valuable trends but also establish a structured approach to better understand the aggregate effects of shock distributions. Thus, this study could be helpful for policy makers to assess trade relationships between countries and obtain quantitative insights for making informed decisions as well as explore the overall state of the globalization as a whole.

Numerical Experiment and Design of a Two-Rod Crank Knee Press with an Internal Layout of the Motor Drive

In crank presses, an important role is played by the presence of actuators with dwell, in which, with continuous movement of the input links, the output working link remains stationary at some part of the work. The use of a high-class structural group (fourth class) expands the functionality of the crank press, including it can ensure the link dwell of the working link on a given section of movement during the required period of time. As a result of the conducted numerical research, four variants of actuators of the crank knee press were designed. Due to the rational choice of the positions of racks and crosshead guide, the best layout of the dimensions of the press mechanism has been achieved. Changing the coordinates of the racks accordingly allows for designing a mechanism with upper or lower dwells of the working links. The duration of the dwell of the working link (slider) can be adjusted by selecting the distance between the racks with rotational pairs and a crosshead guide of the mechanism. All this is shown on the basis of a numerical experiment based on kinematic analysis. In addition, the proposed structure of the mechanism makes it possible to ensure the exact link dwell, which cannot be achieved due to the well-known knee presses based on the second-class mechanism.

Design and Control of Two Stage Battery Charger for Low Voltage Electric Vehicles Using High Gain Buck-Boost PFC AC-DC Converter

The design and control of a two-stage onboard battery charger (OBC) for the low-voltage electric vehicle (LVEVs) are presented in this study. The presented charger operates over a wide range of AC input voltage at high power factor. The presented charger utilizes a bridgeless high gain high power factor AC-DC converter with continuous input current characteristics at its front end. At the back end of the charger, an isolated Cuk DC-DC converter is employed to control and implement different battery charging modes, viz. constant current (CC) and constant voltage (CV) charging profiles. The presented AC-DC converter operates under discontinuous current mode (DCM) operation and achieves minimum control complexity at the AC-DC stage. The DCM design and high voltage conversion ratio allow it to function reliably over a comprehensive range of input and intermediate DC link voltage. This study covers the charger's design for a power rating of 650 W and output battery voltage of 24 to 72 V. The overall operational analysis and effectiveness of the design are verified through both simulations and experimental implementation and the performance is compared with other contemporary power factor correction (PFC) topologies on various parameters.

Assessing the accuracy of modeling the tubbing erector manipulator mechanism in solidworks motion program

Purpose. To estimate the calculation error in determining the kinematic and dynamic characteristics of the UT62 tubbing erector manipulator mechanism movement. Methodology. Modern computer analysis methods are used, which are implemented in a number of computing complexes. Due to the task complexity, a mathematical model for the manipulator mechanism fragment, which is a hydraulic cylinder with two degrees of freedom, has been developed to estimate the error of computer modeling. This model is used as a test model. Findings. On the example of the model study, it is shown that when simulating the mechanism movement, errors in the calculations are possible due to incorrect problem formulation, as well as to the inaccurate settings of the modules for converting the initial data. Under these circumstances, it has been concluded that when the input link movement is specified as a vector, then when determining the kinematic and dynamic characteristics of the mechanism, it is necessary to use a cubic spline in the “interpolator” module. Originality. For the first time, the direct problem of the manipulator mechanism dynamics has been solved, which consists in determining the static and dynamic characteristics of the device according to the given motion law of its drives. It is noted that when the motion is specified in the form of smooth analytical functions, then there is a complete coincidence of the calculation results performed by the SOLIDWORKS MOTION program with those obtained by mathematical modeling. In addition, when the mechanism link input movement is modeled as a vector, which is formed from a discontinuous function, then the cubic spline used in the “interpolator” module provides smooth harmonic functions of the movement, acceleration and jerk processes. As a result of modeling the manipulator mechanism parameters, it turned out that it is not expedient to use more than 50 points of discrete time in the research. Thus, the errors in calculating the maximum power values of the manipulator motors do not exceed 20 % for the power hydraulic cylinder and 5 % for the hydraulic motor. Practical value. The proposed algorithm can be used to model the movement of complex mechanisms in machines.

Modeling of the Process of Shaping Glass Beads According to the Method of Free Lapping

Mathematical modeling of the processing of balls by the method of free lapping using a tool in the form of a hollow thin-walled cylinder (tool bushings) has been performed. An analytical expression has been obtained for calculating the cutting paths, which, according to the formula of F. Preston, are proportional to the amount of material removal from the workpiece being processed. The calculation of the cutting paths in the diametrical sections of the ball during its rotation by a total angle of 4000 radians was carried out. The calculation is performed for various values of such adjustment parameters of the base machine as the amplitude of the reciprocating rotational movement of the device with tool bushings fixed in it, the distance between the symmetry axes of the tool bushings and the axis of rotation of the device, the speed of rotation of the input link of the actuator mechanism of the base machine and a faceplate fixed on its spindle and serving to communicate relative rotation to the ball blanks. In this case, the section with the greatest divergence of cutting paths was considered and the relative value of these paths was determined, which is proportional to the accuracy of processing. Studies have been carried out that have made it possible to identify at least three locations of tool bushings, in which the minimum value of the relative cutting paths on the machined ball surface is achieved, i. e. maximum accuracy of processing, which makes it possible in practice to combine the operations of preliminary, main and final grinding of the parts under consideration. It is shown that the degree of correlation between experimental and theoretical results is at the level of 80–85 %, and the polishing performance according to the proposed scheme increases by about 30 % in comparison with the classical scheme for performing this operation.

Application of the Chebyshev mechanism in the design of the elements of mechanical devices for combing out the down of goats

The process of combing out down in goats still remains practically non-mechanized, and therefore very difficult for operators. For the successful development of the down goat breeding industry, it is necessary to conduct research in the development of mechanical devices that will significantly facilitate the work of operators and will increase their productivity. It is equally important to ensure careful combing of down, which will not cause injury to the animal and will improve the quality of the combed down. When developing a mechanical device for combing down in goats, it is necessary to repeat the process of manual combing of down as accurately as possible. To do this, an analysis of the trajectory of movement of the tip of the comb tooth during manual combing was carried out. Based on the results of the analysis, the scheme of a combing device based on the Chebyshev hinge-lever mechanism was proposed. Analytical equations linking the known parameters of the input (leading) link with the unknown parameters of the driving links are derived within the framework of the analytical method of the kinematic study of mechanisms. Using these equations, it is possible to calculate with a predetermined accuracy the necessary kinematic parameters (displacements, velocities, accelerations, both linear and angular) of the output link and driving links. Based on the results of full-scale modeling and theoretical calculations, the optimal dimensions of the main parts of the device were established. The use of the proposed mechanism will reduce physical effort and operator fatigue, increase productivity due to the abandonment of manual labor and improvement of the device.

STRUCTURE OF THE COMPUTER MODULE OF THE KDAM PROGRAM FOR DETERMINING KINEMATIC AND DYNAMIC PARAMETERS OF THE INPUT LINK

The development of the computer module of the KDAM program for determining the kinematic and dynamic parameters of the input link of the mechanisms of light industry machines allows to determine the coordinates, projections of speeds and accelerations of the center of mass of the crank and the point of attachment of the links of the Asura groups. During the dynamic analysis of the operation of the input link, the projections of the full reaction in the hinge of the input link are determined. The obtained results are used in the program to assess the intensity of technological processes of the light and textile industry when determining the change in the relative tension of the thread in the filling zones on the technological equipment. Lever mechanisms are widely used in light and textile industry machines. The working bodies of the lever mechanisms come into contact with the threads during operation. Depending on the trajectory of the movement, the angle of coverage of the working bodies of the mechanisms of the light and textile industry machines changes. A change in the value of the angle of coverage leads to a change in the tension of the threads. When the coverage angle increases to critical values, the thread may break and the technological equipment may stop. The tension of the thread increases when moving through the refueling zones of the thread feeding system on the technological equipment. This increase is due to the interaction of the thread with the guides and tension devices. The maximum tension value will be in front of the working area. A sharp increase in tension leads to a violation of the normal course of the technological process of thread processing. The development of new schemes of the thread feeding system requires an operational assessment of the value of the tension in front of the working zone. The development of special computer programs for determining the tension in the working area makes it possible to determine the necessary technological parameters. The objective function in the tasks of optimization of technological processes is the minimum necessary tension. The variable parameter in the objective function is the sum of the angles of coverage of the working bodies by the thread. The use of a computer program allows you to determine the tension and change in relative tension in the filling zones of technological machines, which allows you to optimize the shape of the thread supply line even at the stage of designing the technological process. Computer determination of kinematic and dynamic parameters of flat mechanisms allows to determine the parameters used in determining the intensity of technological processes. The study of the influence of the design of the thread tension device on the conditions of its interaction with the thread, taking into account its unevenness in the diameter of the cross section, is important in determining the thread tension. The tension of the thread increases when moving through the refueling zones of the thread feeding system on the technological equipment.

Attention-based BILSTM for the degradation trend prediction of lithium battery

There is an irreversibility in the decline of Li-ion batteries, and the performance of individual cells in the battery pack will gradually decline as the number of times the on-board Li-ion battery is charged and discharged increases This situation can significantly affect the daily use of electric vehicles, for example by shortening the driving range, and in addition, the deterioration of the battery performance increases the probability of electric vehicle breakdowns. Very little work has been done on the prediction of lithium battery performance degradation in long-mileage states, accurate prediction of future battery performance degradation can significantly reduce the probability of EV failure, making battery performance prediction very important. In this paper, we propose a BILSTM network based on an attention mechanism and utilize grey relation analysis and empirical modal decomposition in the input link of the network to address the shortcomings exposed by deep learning in the work on temporal prediction. The adopted approach can effectively address the impact of data noise and redundant features on the prediction work that occurs in deep learning. According to the experimental results, the prediction performance of the model proposed in this paper is found to be higher than other networks in both types of data sets

DNformer: Temporal Link Prediction with Transfer Learning in Dynamic Networks

Temporal link prediction (TLP) is among the most important graph learning tasks, capable of predicting dynamic, time-varying links within networks. The key problem of TLP is how to explore potential link-evolving tendency from the increasing number of links over time. There exist three major challenges toward solving this problem: temporal nonlinear sparsity, weak serial correlation, and discontinuous structural dynamics. In this article, we propose a novel transfer learning model, called DNformer, to predict temporal link sequence in dynamic networks. The structural dynamic evolution is sequenced into consecutive links one by one over time to inhibit temporal nonlinear sparsity. The self-attention of the model is used to capture the serial correlation between the input and output link sequences. Moreover, our structural encoding is designed to obtain changing structures from the consecutive links and to learn the mapping between link sequences. This structural encoding consists of two parts: the node clustering encoding of each link and the link similarity encoding between links. These encodings enable the model to perceive the importance and correlation of links. Furthermore, we introduce a measurement of structural similarity in the loss function for the structural differences of link sequences. The experimental results demonstrate that our model outperforms other state-of-the-art TLP methods such as Transformer, TGAT, and EvolveGCN. It achieves the three highest AUC and four highest precision scores in five different representative dynamic networks problems.

Optimization of the operation of the mechanism of the cross planer

The subject of the research is the optimization of the mechanism of the cross planer. In the article, on the basis of the condition of closed contours, the equations of the projection of the links on the corresponding coordinate axes are compiled. A functional relationship has been established between the kinematic parameters characterizing the movement of the input and output links of the mechanism. The obtained numerical calculations are presented in the form of graphic dependences. The aim of the work is the optimal metric synthesis of the mechanism of a cross-planer, with parametric restrictions. The conclusions obtained in the article can be used to improve and design modern technological equipment with mechanisms similar to the mechanism of a cross-cutting machine.

SLIPPING MOTION IN NUTLESS PLANETARY ROLLER SCREW MECHANISMS OF LINEAR ELECTROMECHANICAL DRIVES

Rolling screw mechanisms, used in linear electromechanical drives, have many advantages and disad-vantages as well. The most important of these is slipping. The most promising roller screw mechanisms are planetary roller screw mechanisms, the manufacture of threaded parts of which requires expensive special machines manufactured by Western companies. Taking into account the import substitution strategy, nut-less roller screw mechanisms (NRSM) were developed and patented in Russia, in which a threaded part that is the most difficult to manufacture, namely a nut, the high-precision internal multistart thread of which is tempered to a high hardness, is absent. Using domestic universal machines, prototype NRSM samples were made, which were subject to comprehensive experimental studies. It turned out that the neg-ative impact of slipping is felt to a greater extent for prototype NRSM samples than for known designs of planetary roller screw mechanisms. To reduce this impact, the paper considers in detail the process of slipping and the main reasons that cause it. In addition, the results of experimental studies of this phe-nomenon using prototype samples are analyzed. It turned out that the slipping motion depends on: the value of the angular velocity of the input link of the mechanism, the value of the axial force that the out-put link of the mechanism overcomes over the full (forward and reverse) stroke, the manufacturing accuracy of threaded parts of NRSM, the direction of the axial force (along the longitudinal axis x or against it). The latter is an important scientific finding in the study of the slipping motion in NRSM. Another rea-son for a slipping motion is the design feature of the prototype sample, which had rollers with a modified profile. Usually, the profile of the roller turns is drawn along the arc of the circle, the center of which is located on the roller axis. The modified profile of the roller turns consists of three series-connected straight line segments, which affects the transmission ratio of the mechanism. For comparison, it is neces-sary to perform an experiment with a mechanism having rollers with a traditional profile of turns.

Design methods of planar six-bar mechanism in servo applications

ABSTRACT Aiming at improving the reliability of the hydraulic servo actuator constructed using a nozzle-flapper servo valve, the design of a servo actuator with a combination of electro-hydraulic and mechanical manipulations is proposed. This solution enables the system to be switched to a mechanical operation pattern in the event of failure of the electro-hydraulic servo valve, which results in a loss of control. A 2-degrees of freedom planar six-bar lower-pair mechanism is proposed to achieve mechanically operated hydraulic servo-driven actions in a switched pattern. The dimensional synthesis of the mechanism is completed by applying the adaptive particle swarm optimization (APSO), and optimized numerical solutions are obtained. The virtual prototype of the mechanism is designed, and the kinematic properties of the output link along with the sinusoidal motion of the given input links are assessed using the mathematical software ADAMS. The simulation results show that the optimally designed planar six-bar mechanism has small geometric errors, thus verifying that APSO can be satisfactorily applied in dimensional synthesis.

Bioinspired flapping wing UAV and its kinematic analysis—a novel approach

A rich development in the domain of flapping wing Unmanned Aerial Vehicle (FWUAV) is not yet entirely sufficient to implement the findings of real-life situations. Using the limited knowledge of this domain, this work enlightens the scientific community by introducing a homegrown, patented flapping mechanism of foldable wing aerial vehicle. The synchronized dual wing flapping mechanism consists of a crank slotted lever, a gear train and a special type of 4 bar kinematic chain. The entire sets are powered by a DC motor through crank connected motor shaft. Flapping cycle works on quick return principle generated by crank slotted lever mechanism and foldable wing structure by the special type 4 bar chain with gear train ensure the controlled flapping frequency, twist angle, altitude gain and attitude parameters (Pitch, roll, yaw). This work majorly focuses on the kinematics of the developed bio mimic mechanism by observing the variation of flapping wing orientation, angular velocity and angular acceleration with respect to the crank rotation as well as different crank speeds. These analytically obtained kinematic parameters are further validated after developing a three-dimensional model of the said mechanism as well as multibody analysis by MSC ADAMS. The patterns of the kinematic parameters such that angular displacement, angular velocity and angular acceleration between output and input links are similar and its validation guarantees the correctness of developed mechanism. The kinematic analyzes of linkages are also essential for dynamic study as well as fabrication of prototype.

Outage Performance Estimation of a MISO FSO System with OOK Signaling and Alamouti Type Space-Time Coding

In this work, multi input and single output optical wireless communication (OWC) links are analyzed, assuming the channel experiences fading due to atmospheric turbulence. OOK signaling and Alamouti-type space-time coding with intensity modulation and direct detection is assumed for weak to strong turbulence conditions modeled with the gamma–gamma distribution and closed form analytical expressions for their outage probability are derived for the first time, to the best of our knowledge. Finally, the corresponding numerical results are obtained, through the obtained mathematical expressions. Performance of a multi input and single output channel is analyzed for its outage probability as a function of power to noise ratio and normalized threshold. Three different cases for strong, medium, and weak turbulences are investigated.

Design of Fixed-Sequence Planar 5R Symmetrical Parallel Manipulators

Designing manipulation systems where the gripper has predetermined initial and final positions is an important practical consideration in modern robotics; in other words, achieving the objective of moving the payload along a non-imposed trajectory between two given positions, with the ability to change these positions periodically. One solution to the problem is to create a one-degree-of-freedom system with adjustable parts. This approach is considered optimal in terms of its simplified control and minimum energy expenditure. The merit of the solution is that manipulation systems of this type with cyclic control have only one actuator; the simple design and the control system improve the operational reliability of the mechanical system while greatly reducing the cost of it. The present work proposes a new design concept for a planar 5R symmetrical parallel manipulator. The aim of the proposed design principle is that the two input links of the manipulator are interconnected. The last one is determined in such a way that the initial and final positions of the gripper are ensured. Thus, the obtained mechanical system, having only one actuator, ensures the movement of the gripper between predetermined initial and final positions. The dynamics of the manipulation system, in particular the balancing of shaking force and shaking moment to reduce vibration in the frame, are considered in addition to the purely kinetic aspects. Numerical simulations are used to illustrate the proposed design concept.