72 research outputs found
CAT-RRT: Motion Planning that Admits Contact One Link at a Time
Current motion planning approaches rely on binary collision checking to
evaluate the validity of a state and thereby dictate where the robot is allowed
to move. This approach leaves little room for robots to engage in contact with
an object, as is often necessary when operating in densely cluttered spaces. In
this work, we propose an alternative method that considers contact states as
high-cost states that the robot should avoid but can traverse if necessary to
complete a task. More specifically, we introduce Contact Admissible
Transition-based Rapidly exploring Random Trees (CAT-RRT), a planner that uses
a novel per-link cost heuristic to find a path by traversing high-cost obstacle
regions. Through extensive testing, we find that state-of-the-art optimization
planners tend to over-explore low-cost states, which leads to slow and
inefficient convergence to contact regions. Conversely, CAT-RRT searches both
low and high-cost regions simultaneously with an adaptive thresholding
mechanism carried out at each robot link. This leads to paths with a balance
between efficiency, path length, and contact cost
Bilevel Optimization for Just-in-Time Robotic Kitting and Delivery via Adaptive Task Segmentation and Scheduling
Kitting refers to the task of preparing and grouping necessary parts and
tools (or "kits") for assembly in a manufacturing environment. Automating this
process simplifies the assembly task for human workers and improves efficiency.
Existing automated kitting systems adhere to scripted instructions and
predefined heuristics. However, given variability in the availability of parts
and logistic delays, the inflexibility of existing systems can limit the
overall efficiency of an assembly line. In this paper, we propose a bilevel
optimization framework to enable a robot to perform task segmentation-based
part selection, kit arrangement, and delivery scheduling to provide
custom-tailored kits just in time - i.e., right when they are needed. We
evaluate the proposed approach both through a human subjects study (n=18)
involving the construction of a flat-pack furniture table and shop-flow
simulation based on the data from the study. Our results show that the
just-in-time kitting system is objectively more efficient, resilient to
upstream shop flow delays, and subjectively more preferable as compared to
baseline approaches of using kits defined by rigid task segmentation boundaries
defined by the task graph itself or a single kit that includes all parts
necessary to assemble a single unit.Comment: IEEE International Conference on Robot & Human Interactive
Communication 202
The influence of autistic symptoms on social and non-social cognition and on real-life functioning in people with schizophrenia: Evidence from the Italian Network for Research on Psychoses multicenter study
BACKGROUND: Autism spectrum disorders (ASDs) and schizophrenia spectrum disorders (SSDs), although conceptualized as separate entities, may share some clinical and neurobiological features. ASD symptoms may have a relevant role in determining a more severe clinical presentation of schizophrenic disorder but their relationships with cognitive aspects and functional outcomes of the disease remain to be addressed in large samples of individuals. AIMS: To investigate the clinical, cognitive, and functional correlates of ASD symptoms in a large sample of people diagnosed with schizophrenia. METHODS: The severity of ASD symptoms was measured with the PANSS Autism Severity Scale (PAUSS) in 921 individuals recruited for the Italian Network for Research on Psychoses multicenter study. Based on the PAUSS scores, three groups of subjects were compared on a wide array of cognitive and functional measures. RESULTS: Subjects with more severe ASD symptoms showed a poorer performance in the processing speed (p\ua0=\ua00.010), attention (p\ua0=\ua00.011), verbal memory (p\ua0=\ua00.035), and social cognition (p\ua0=\ua00.001) domains, and an overall lower global cognitive composite score (p\ua0=\ua00.010). Subjects with more severe ASD symptoms also showed poorer functional capacity (p\ua0=\ua00.004), real-world interpersonal relationships (p\ua0<\ua00.001), and participation in community-living activities (p\ua0<\ua00.001). CONCLUSIONS: These findings strengthen the notion that ASD symptoms may have a relevant impact on different aspects of the disease, crucial to the life of people with schizophrenia. Prominent ASD symptoms may characterize a specific subpopulation of individuals with SSD
Sex and gender differences in clinical and functional indices in subjects with schizophrenia and healthy controls: Data from the baseline and 4-year follow-up studies of the Italian Network for Research on Psychoses
Gender differences in clinical and psychosocial aspects of schizophrenia have been widely reported. Findings have not always been consistent, and some of them need further research. In a large sample of community dwelling persons with schizophrenia, we investigated gender differences in clinical, cognitive and functional indices, as well as their changes over a 4-year follow-up and their impact on real-life functioning. Gender differences in personal resources, cognitive and functional indices were explored also in a sample of healthy controls. Men with respect to women had an earlier age of illness onset, a worse premorbid adjustment in the academic domain, more severe avolition, expressive deficit and positive symptoms, lower prevalence of comorbidity for affective disorders, less frequent use of two coping strategies ('religion' and 'use of emotional support') and more frequent positive history of substance and alcohol abuse. In addition, men were more impaired in verbal learning, while women in reasoning/problem solving. Some patterns of gender differences observed in healthy controls were not confirmed in patients. Men's disadvantages in the clinical picture did not translate into a worse outcome. This finding may be related to the complex interplay of several factors acting as predictors or mediators of outcome
Accuracy of self-assessment of real-life functioning in schizophrenia
A consensus has not yet been reached regarding the accuracy of people with schizophrenia in self-reporting their real-life functioning. In a large (n=618) cohort of stable, community-dwelling schizophrenia patients we sought to: (1) examine the concordance of patients' reports of their real-life functioning with the reports of their key caregiver; (2) identify which patient characteristics are associated to the differences between patients and informants. Patient-caregiver concordance of the ratings in three Specific Level of Functioning Scale (SLOF) domains (interpersonal relationships, everyday life skills, work skills) was evaluated with matched-pair t tests, the Lin's concordance correlation, Somers' D, and Bland-Altman plots with limits of agreement (LOA). Predictors of the patient-caregiver differences in SLOF ratings were assessed with a linear regression with multivariable fractional polynomials. Patients' self-evaluation of functioning was higher than caregivers' in all the evaluated domains of the SLOF and 17.6% of the patients exceeded the LOA, thus providing a self-evaluation discordant from their key caregivers. The strongest predictors of patient-caregiver discrepancies were caregivers' ratings in each SLOF domain. In clinically stable outpatients with a moderate degree of functional impairment, self-evaluation with the SLOF scale can become a useful, informative and reliable clinical tool to design a tailored rehabilitation program
Does social cognition change? Evidence after 4Â years from the Italian Network for Research on Psychoses
BackgroundDeficits in social cognition (SC) are significantly related to community functioning in schizophrenia (SZ). Few studies investigated longitudinal changes in SC and its impact on recovery. In the present study, we aimed: (a) to estimate the magnitude and clinical significance of SC change in outpatients with stable SZ who were assessed at baseline and after 4 years, (b) to identify predictors of reliable and clinically significant change (RCSC), and (c) to determine whether changes in SC over 4 years predicted patient recovery at follow-up. MethodsThe reliable change index was used to estimate the proportion of true change in SC, not attributable to measurement error. Stepwise multiple logistic regression models were used to identify the predictors of RCSC in a SC domain (The Awareness of Social Inference Test [TASIT]) and the effect of change in TASIT on recovery at follow-up. ResultsIn 548 participants, statistically significant improvements were found for the simple and paradoxical sarcasm of TASIT scale, and for the total score of section 2. The reliable change index was 9.8. A cut-off of 45 identified patients showing clinically significant change. Reliable change was achieved by 12.6% and RCSC by 8% of participants. Lower baseline TASIT sect. 2 score predicted reliable improvement on TASIT sect. 2. Improvement in TASIT sect. 2 scores predicted functional recovery, with a 10-point change predicting 40% increase in the probability of recovery. ConclusionsThe RCSC index provides a conservative way to assess the improvement in the ability to grasp sarcasm in SZ, and is associated with recovery
Tolerability and efficacy of vortioxetine versus SSRIs in elderly with major depression. Study protocol of the VESPA study: a pragmatic, multicentre, open-label, parallel-group, superiority, randomized trial
Depression is a highly prevalent condition in the elderly, with a vast impact on quality of life, life expectancy, and medical outcomes. Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed agents in this condition and, although generally safe, tolerability issues cannot be overlooked. Vortioxetine is an antidepressant with a novel mechanism of action. Based on studies to date, it may have a promising tolerability profile in the elderly, as it does not adversely affect psychomotor or cognitive performance and does not alter cardiovascular and endocrine parameters. The present study aims to assess the tolerability profile of vortioxetine in comparison with the SSRIs considered as a single group in elderly participants with depression. The rate of participants withdrawing from treatment due to adverse events after 6 months of follow up will be the primary outcome
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