Sensor-based skeleton modeling and MVEEs approach of the redundant manipulator for reaction motion

With the wide application of redundant manipulators, sharing a working space with humans and dealing with uncertainty seems an inevitable problem, especially in the dynamic and unstructured domain. How to deal with obstacle avoidance is of particular importance that robots and humans/environments are safe interactions to fulfill the complex cooperating tasks. This paper aimed at solving the problem of multiple points avoidance for the reaction motion based on the skeleton algorithm in unstructured and dynamic environments. A method named “sensor-based skeleton modeling and MVEEs approach of the redundant manipulator for the reaction motion” is proposed. The extraction of skeleton information from image is obtained to calculate the distances of the multiple control points and establish the repulsion in this method. Afterward, the force Jacobian related to the priority weighting factors is calculated and then a reaction force with damping term is established, which is corresponding nominal torque commands. For the redundant manipulator, the joint angles are obtained through torque iteration instead of inverse kinematics to reduce calculation cost. Finally, the method was tested by a 7-DOF manipulator in the ROS framework. The obtained results indicate that the method in this method can realize dynamic obstacle avoidance and time cost reduction.

The Amistad Saga: A Transatlantic Dialogue

The story of the slave ship La Amistad is one of the most celebrated and narrated 19th-century stories of the transatlantic slave trade. To fully appreciate the significance and impact of the events and circumstances of this fateful episode, it is important to examine its legacy from multiple points of the Atlantic world—vestiges of the triangular trade bequeathed by the Columbian Exchange. For a long time, the Amistad saga has been viewed from a very US-centric perspective because the dispute over the lives of the Africans rose to the US Supreme Court in 1840–1841. New archival and oral research in West Africa, Europe, and the Caribbean is rebalancing the narrative and revising the historical drama. Today, the Amistad story is widely recognized as a quintessentially Atlantic story, a story of mobility that moves back and forth across the Atlantic in multiple directions over many decades. The deployment of the phrase “Amistad saga” provides a vehicle with which to critique the socio-legal battles about transatlantic slave trading in Caribbean, North American, and West African history. The Amistad story is often described as pre-incidental to the US Civil War. The victory of African defendants is often framed as a self-congratulatory vindication of the successful resistance of enslaved Africans. The celebrated figure of “Joseph Cinqué” or Sengbe Pieh, the self-appointed leader of the Africans, and a replica of the ship itself are part of an Amistad memory industry that attempts to narrate the slave trade and its abolition. A new framework for teaching and understanding the history of the Amistad saga and its memory and forgetting through an Atlantic lens must combine historical and contemporary perspectives from the United States, Europe, Cuba, and Sierra Leone.

Simulation evaluation on a compact monitor for gamma-emitting tracers in plant stems

Non-destructive monitoring of radioactivities derived from radioactive tracers at multiple points in plant stems can be used to evaluate the velocity of element transport in living plants. In this study, we calculated absorption-efficiency distributions for several detector geometries to determine appropriate shapes for non-destructive monitoring of radioactivities in the stem. The efficiency distributions were calculated by Monte Carlo simulations, and the flatnesses and spatial resolutions were evaluated. It was found that the placement of four detectors around the stem could limit the percentage of standard deviation to the mean of the pixel values to less than 5%. We could determine a compact detector geometry with the spatial resolution of 1.35 cm using four small detectors. The detection efficiencies were 0.014, 0.0030 and 0.00063 cm at the initial gamma-ray energies of 0.5, 1 and 2 MeV, which is sufficiently applicable to detect 10 kBq/cm of radioactivity.

Sciences, Philosophies, and the Question of Borders

This essay contributes in part to the discussion of the concept of the border [frontière] and its relations between philosophies and sciences present within the work Épistémologie des frontières. It suggests that borders function as both a separation and a union between the domains of philosophies and sciences in their multiplicity. Borders are determinant in the times of interdisciplinarity, and such investigations are necessary because the accustomed links between philosophies and sciences can no longer be assumed. This essay proposes some hypotheses concerning methodology and the relation to the real to exercise a modelization as the articulation of multiple points of view. Modelization allows for the invention of democratic pragmatics of philosophy/philosophies towards a global re-evaluation of the relations that disciplines, such as the sciences and ethics, share with philosophy

ForestScanner: A mobile application for measuring and mapping trees with LiDAR-equipped iPhone and iPad

Terrestrial laser scanning (TLS) is becoming increasingly popular as an alternative means to conventional forest inventory methods. By gauging the distances to multiple points on the surrounding object surfaces, TLS acquires 3D point clouds from which tree sizes and spatial distributions can be rapidly estimated. However, the high cost and specialized skills required for TLS have put it out of reach for many potential users. We here introduce ForestScanner, a free, mobile application that allows TLS-based forest inventories by means of iPhone or iPad with a built-in LiDAR sensor. ForestScanner does not require any manual analysis of 3D point clouds. As the user scans trees with an iPhone/iPad, ForestScanner estimates the stem diameters and spatial coordinates based on real-time instance segmentation and circle fitting. The users can visualize, check, and share the results of scanning in situ. By using ForestScanner, we measured the stem diameters and spatial coordinates of 672 trees within a 1 ha plot in 1 h 39 min with an iPhone and in 1 h 38 min with an iPad (diameter ≥5 cm; detection rate = 100%). ForestScanner reduced the person-hours required for measuring diameters to 25.7%, mapping trees to 9.3%, and doing both to 6.8% of the person-hours taken using a dimeter tape and a conventional surveying method. The diameters measured by ForestScanner and diameter tape were in good agreement; R2=0.963 for iPhone and R2=0.961 for iPad. ForestScanner and the conventional surveying system showed almost identical results for tree mapping (assessed by the spatial distances among trees within 0.04 ha subplots); Mantel R2=0.999 for both iPhone and iPad. Our results indicate that ForestScanner enables cost-, labor-, and time-efficient forest inventories. The application can increase the accessibility to TLS for people beyond specialists and enhance resource assessments and biodiversity monitoring in forests worldwide.

MODELING LIFETIME EXPECTED CREDIT LOSSES ON BANK LOANS

The guidelines of various Accounting Standards require every financial institution to measure lifetime expected credit losses (LECLs) on every instrument, and to determine at each reporting date if there has been a significant increase in credit risk since its inception. This paper models LECLs on bank loans given to a firm that has promised to repay debt at multiple points over the lifetime of the contract. The LECL can be written as a sum of ECLs (estimated at reporting date) incurred at debt repayment times. The ECL at any debt repayment time can be written as a product of the probability of default (PD), the expected value of loss given default and the exposure at default. We derive a stochastic dynamical equation for the value of the firm’s asset by incorporating the dynamics of the factors. Also, we show how the LECL and the term structure of the PD can be estimated by solving a Black–Scholes–Merton like partial differential equation. As an illustration, we present the numerical results for the various credit loss indicators of a fictitious firm when the dynamics of the short-term interest rate is characterized by a Cox–Ingersoll–Ross mean-reverting process.

Control of Laser Scanner Trilateration Networks for Accurate Georeferencing of Caves: Application to El Castillo Cave (Spain)

There is a growing demand for measurements of natural and built elements, which require quantifiable accuracy and reliability, within various fields of application. Measurements from 3D Terrestrial Laser Scanner come in a point cloud, and different types of surfaces such as spheres or planes can be modelled. Due to the occlusions and/or limited field of view, it is seldom possible to survey a complete feature from one location, and information has to be acquired from multiple points of view and later co-registered and geo-referenced to obtain a consistent coordinate system. The aim of this paper is not to match point clouds, but to show a methodology to adjust, following the traditional topo-geodetic methods, 3DTLS data by modelling references such as calibrated spheres and checker-boards to generate a 3D trilateration network from them to derive accuracy and reliability measurements and post-adjustment statistical analysis. The method tries to find the function that best fits the measured data, taking into account not only that the measurements made in the field are not perfect, but that each one of them has a different deviation depending on the adjustment of each reference, so they have to be weighted accordingly.

Impact of COVID-19 on patient and healthcare professional attitudes, beliefs, and behaviors toward the healthcare system and on the dynamics of the healthcare pathway

Background COVID-19 has dramatically changed how healthcare is delivered and experienced. Methods One-on-one interviews and a virtual ethnographic roundtable were conducted among 45 patients, caregivers, and healthcare professionals (HCPs) in 4 therapeutic areas from the United States and Japan: overactive bladder, vasomotor symptoms, prostate cancer, and metastatic urothelial carcinoma. The goal was to identify the impact of COVID-19 on patient/caregiver and HCP attitudes, interactions, beliefs, and behaviors toward the healthcare system and care pathway. Results Four foundational themes were identified: 1) COVID-19 risk is relative; 2) isolation is collateral damage; 3) telehealth is a parallel universe; and 4) COVID-19 is destabilizing the foundations of healthcare. Numerous insights, influenced by diverse cultural, social, and psychological factors, were identified within each theme. Conclusions The impacts of COVID-19 were noticeable at multiple points of care during the “universal” care pathway, including at initial screening, referral to specialists, diagnosis, treatment initiation/surgery, and during ongoing care. Greater appreciation of the short- and long-term impacts of COVID-19 and resulting gaps in care may act as a catalyst for positive change in future patient care.