Updated Path Research Articles

Multi-Point Path Planning Algorithm for a Mobile Robot With Composite Moving Costs

Abstract Multi-point path planning problem is a classic problem of the mobile robot. The present research is concerned with solving the shortest path. In some realistic applications, the shortest path length is not always the significant concerned value of path planning. This article proposes an extended generalized cost concept to constitute the updated path planning strategy. The generalized costs are the combination of straightly moving and turning costs. A genetic algorithm is used to solve optimal path-planning problems. The different weight between the two kinds of costs and how the different parameters affect the optimal path solution is discussed. The generalized cost concept extends the application of path planning to diversified physical quantities. When estimating the composite optimal costs of the path planning problem, we only need to solve the path planning problem with simplex straightly moving costs or simplex turning costs.

Along the allostery stream: Recent advances in computational methods for allosteric drug discovery

AbstractAllostery is a universal, biological phenomenon in which orthosteric sites are fine‐tuned by topologically distal allosteric sites triggered by perturbations, such as ligand binding, residue mutations, or post‐translational modifications. Allosteric regulation is implicated in a variety of physiological and pathological conditions and is thus emerging as a novel avenue for drug discovery. Allosteric drugs have traditionally been discovered by serendipity through large‐scale experimental screening. Recently, we have witnessed significant progress in biophysics, particularly in structural bioinformatics, which has facilitated the in‐depth characterization of allosteric effects and the accurate detection of allosteric residues and exosites. These advances improve our understanding of allosterism and promote allosteric drug discovery, thereby revolutionizing the shift from the traditional serendipitous route used to discover allosteric drugs to the updated path centered on rational structure‐based design. In this review, recent advances in computational methods applied to allosteric drug discovery are summarized. We comprehensively review these achievements along various levels of allosteric events, from the construction of allosteric databases to the identification and analysis of allosteric residues, signals, sites, and modulators. We expect to increase the awareness of the discovery of allosteric drugs using structure‐based computational methods.This article is categorized under:Structure and Mechanism > Computational Biochemistry and Biophysics

ЕЛЕКТРОННІ ГРОШІ ЯК НОВА ФОРМА ФІНАНСОВО-ЕКОНОМІЧНИХ ВІДНОСИН В УМОВАХ ЦИФРОВІЗАЦІЇ ЕКОНОМІКИ ТА СУСПІЛЬСТВА

The impact of the development of the digital economy on reformatting the spheres of economic and public life is determined. It is revealed that the significant weight of financial and economic relations in the field of exchange, distribution and redistribution processes, which are manifested in cash flows, began to be occupied by transactions of electronic commodity-money circulation, requiring updated financial relations and providing for the formation and organization of payment systems, instruments based on the circulation of electronic money. The essence of electronic money, its subspecies has been clarified, the scope of application has been determined It is noted that in order to provide an updated path for the development of financial and economic relations, new payment systems are being formed, which, competing with each other, create more efficient and convenient platforms for making electronic payments.

Path Travel Time Estimating Method by Incomplete Traffic Data

This study proposes a method estimating stochastic path travel times by using both traffic counter data and probe car data complementarily. A stochastic traffic demand for each O-D pair in a road network is estimated by maximum likelihood estimation with respect to traffic counter data. Stochastic path travel times are addressed as a prior multivariate path travel time distribution. The estimated stochastic path travel time is updated by applying Bayesian inference using observed probe car data. The updated path travel time can be regarded as a posterior multivariate path travel time distribution. Numerical experiments demonstrate inference processes of path travel time and verify our proposed model.

Force-Controlled Exploration for Updating Virtual Fixture Geometry in Model-Mediated Telemanipulation

This paper proposes an approach for using force-controlled exploration data to update and register an a priori virtual fixture geometry to a corresponding deformed and displaced physical environment. An approach for safe exploration implementing hybrid motion/force control is presented on the slave robot side. During exploration, the shape and the local surface normals of the environment are estimated and saved in an exploration data set. The geometric data collected during this exploration scan are used to deform and register the a priori environment model to the exploration data set. The environment registration is achieved using a deformable registration based on the coherent point drift method. The task-description of the high-level assistive telemanipulation law, called a virtual fixture (VF), is then deformed and registered in the new environment. The new model is updated and used within a model-mediated telemanipulation framework. The approach is experimentally validated using a da-Vinci research kit (dVRK) master interface, a dVRK patient side manipulator, and a Cartesian stage robot. Experiments demonstrate that the updated VF and the updated model allow the users to improve their path following performance and to shorten their completion time when the updated path following VF is applied. The approach presented has direct bearing on a multitude of surgical applications including force-controlled ablation.

Online Path Planning for Surface Vehicles Exposed to Unknown Ocean Currents Using Pseudospectral Optimal Control

Abstract: This paper investigates the feasibility of using pseudospectral (PS) optimal control in real-time path planning for marine surface vehicles in environments where both obstacles and unknown disturbances are present. In particular, the simplified kinematic equations of an underactuated marine surface vehicle exposed to unknown ocean currents are considered, and the software package DIDO is used to compute the optimal path via PS optimization, initially assuming the ocean current is zero. In that case, the resulting path is minimum-length (similar to Dubins path) but not minimum-time. The main contribution concerns the addition of a nonlinear observer, which estimates online the effects of the ocean current on the vehicle, and that of a guidance system which generates appropriate reference trajectories in order to minimize the position error and track the optimal trajectory successfully. It is shown that through occasional replanning, according to the information about the ocean current parameters coming from the observer, the updated path converges to the minimum-time path. Two different implementations of the approach are presented and illustrated through numerical simulations.

The Consolidated Medium-Term Income and Expenditure Framework

The medium-term income projections have been updated since the last estimate provided to the Executive Board in April 2014. The main changes to the outlook stem from a lower path for credit outstanding and expectations for a more gradual rise in interest rates. The revised projections show lower levels of net operational income over the coming years. Lending income is lower compared with earlier estimates as a result of lower credit levels, including the advance repurchases by Ireland and Portugal. Non-lending income is also projected to be lower reflecting a further downward shift in SDR interest rates and, thus, returns on investments and interest-free resources. The updated expenditure path assumes the net administrative budget remains constant in real terms at the FY 2012 level. The long-run projections indicate a broad balance between income and expenditures, assuming that interest rates rise to 3.5 percent and with lending returning to pre-crisis levels. The pace of reserve accumulation is expected to slow, reflecting the decline in Fund credit, and precautionary balances are now projected to remain slightly below the projected target of SDR 20 billion over the medium term compared with the earlier estimates.

The Consolidated Medium-Term Income and Expenditure Framework

The medium-term income projections have been updated since the last estimate provided to the Executive Board in April 2013. Lending income is higher compared with the earlier estimates as a result of new arrangements approved since April 2013. Non-lending income is lower primarily due to revised projections for investment income. The updated expenditure path assumes the net administrative budget remains constant in real terms at the FY 2014 level, implying a nominal medium-term path that is somewhat higher than in the April 2013 projections. Precautionary balances are projected to reach the current target of SDR 20 billion in FY 2018. The projections also illustrate a broad balance between income and expenditures even if lending were to return to pre-crisis levels.

The Consolidated Medium-Term Income and Expenditure Framework

The medium-term projections of Fund income and precautionary balances accumulation have been updated since the April 2012 projections. The overall income outlook remains positive with continued high lending income expected in the medium-term. The projections indicate a downward shift in the income path primarily due to lower non-lending income as a result of the low global interest rates and the agreement to phase in investments under the new gold-sales funded endowment. The updated expenditure path has not changed significantly. The projections also illustrate a broad balance between income and expenditures when lending returns to pre-crisis levels. The accumulation of precautionary balances remains strong in the medium-term. The indicative medium-term target of SDR 20 billion is now expected to be reached by FY18–FY19.

An optimized strategy for update path selection in unstructured P2P networks

With the growth of P2P file sharing systems, people are no longer satisfied with the sharing of the read-only and static files, and thus the systems with mutually writable and dynamic files have emerged, resulting in the replica inconsistency problem. To maintain the replica consistency, too many update messages need to be redundantly propagated due to the lack of the sharing of globally updated path information in the existing strategies. To address this problem, we propose an optimized strategy for update path selection, which makes the nodes share the update path information by using clone, variation and crossover operations for the update paths. We also present a repeated update strategy to cope with the churn problem so as to maintain replica consistency as far as possible even if some nodes temporarily leave the network. The simulation results show that our strategy can significantly reduce the number of the redundant update messages without lowering the message coverage, thus improving the availability of the unstructured P2P networks.

Updated Tool Path Model Including Rotating Speed for Cutting Force Prediction in High-Speed Milling

Updated Tool Path Model Including Rotating Speed for Cutting Force Prediction in High-Speed Milling

Gateway discovery algorithm based on multiple QoS path parameters between mobile node and gateway node

Several gateway selection schemes have been proposed that select gateway nodes based on a single Quality of Service (QoS) path parameter, for instance path availability period, link capacity or end-to-end delay, etc. or on multiple non-QoS parameters, for instance the combination of gateway node speed, residual energy, and number of hops, for Mobile Ad hoc NETworks (MANETs). Each scheme just focuses on the ment of improve only a single network performance, i.e., network throughput, packet delivery ratio, end-to-end delay, or packet drop ratio. However, none of these schemes improves the overall network performance because they focus on a single QoS path parameter or on set of non-QoS parameters. To improve the overall network performance, it is necessary to select a gateway with stable path, a path with the maximum residual load capacity and the minimum latency. In this paper, we propose a gateway selection scheme that considers multiple QoS path parameters such as path availability period, available capacity and latency, to select a potential gateway node. We improve the path availability computation accuracy, we introduce a feedback system to updated path dynamics to the traffic source node and we propose an efficient method to propagate QoS parameters in our scheme. Computer simulations show that our gateway selection scheme improves throughput and packet delivery ratio with less per node energy consumption. It also improves the end-to-end delay compared to single QoS path parameter gateway selection schemes. In addition, we simulate the proposed scheme by considering weighting factors to gateway selection parameters and results show that the weighting factors improve the throughput and end-to-end delay compared to the conventional schemes.

Nest mark orientation in desert ants Cataglyphis: what does it do to the path integrator?

In desert ants, path integration is the fundamental system of long-distance navigation. Normally, the path integrator is reset to the zero state whenever the ant returns to the starting point of its foraging journey, the nest. We investigated whether the landmark panorama characterizing the nest entrance suffices to reset the path integrator. We designed an experimental paradigm in which the position where the ants’ path integrator was at the zero state (PI position) did not coincide with the position of the nest as marked by the familiar landmark panorama (LM position). Once the ants displaced from the training area to a distant test field had arrived at the PI position, the artificial landmark array defining the nest site was installed at the LM position. The ants immediately headed towards the LM position and searched there persistently. However, upon removal of the landmarks they returned to the PI position. Hence, they ignored information from their path integrator while they concentrated their search at the landmark-defined nest position, but they again relied on their continually updated path integrator as soon as the landmarks had been removed. Although their concentrated search at the LM position showed that the ants had used the landmarks as reliable cues for the position of their nest, this landmark-induced search for the nest entrance did not reset the ant’s path integrator. In general, this might mean that geocentric visual cues in themselves are not sufficient to recalibrate the egocentric path integrator.