Orienting polyhedral parts by pushing

A common task in automated manufacturing processes is to orient parts prior to assembly. We consider sensorless orientation of an asymmetric polyhedral part by a sequence of push actions, and show that is it possible to move any such part from an unknown initial orientation into a known final orientation if these actions are performed by a jaw consisting of two orthogonal planes. We also show how to compute an orienting sequence of push actions.We propose a three-dimensional generalization of conveyor belts with fences consisting of a sequence of tilted plates with curved tips; each of the plates contains a sequence of fences. We show that it is possible to compute a set-up of plates and fences for any given asymmetric polyhedral part such that the part gets oriented on its descent along plates and fences

Вимоги видавничого відділу ІМФЕ ім. М. Т. Рильського до оформлення авторами рукописів

Industrial parts are manufactured to tolerances as no production process is capable of delivering perfectly identical parts. It is unacceptable that a plan for a manipulation task that was determined on the basis of a CAD model of a part fails on some manufactured instance of that part, and therefore it is crucial that the admitted shape variations are systematically taken into account during the planning of the task. We study the problem of orienting a part with given admitted shape variations by means of pushing with a single frictionless jaw. We use a very general model for admitted shape variations that only requires that any valid instance must contain a given convex polygon PI while it must be contained in another convex polygon PE. The problem that we solve is to determine, for a given h, the sequence of h push actions that puts all valid instances of a part with given shape variation into the smallest possible interval of final orientations. The resulting algorithm runs in O(hn) time, where n=|PI|+|PE|

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Practice explains abolished behavioral adaptation after human dorsal anterior cingulate cortex lesions

The role of mid-cingulate cortex (MCC), also referred to as dorsal anterior cingulate cortex, in regulating cognitive control is a topic of primary importance in cognitive neuroscience. Although many studies have shown that MCC responds to cognitive demands, lesion studies in humans are inconclusive concerning the causal role of the MCC in the adaptation to these demands. By elegantly combining single-cell recordings with behavioural methods, Sheth et al. [Sheth, S. et al. Human dorsal anterior cingulate cortex neurons mediate ongoing behavioural adaptation. Nature 488, 218–22 (2012).] recently were able to show that neurons in MCC encode cognitive demand. Importantly, this study also claimed that focal lesions of the MCC abolished behavioural adaptation to cognitive demands. Here we show that the absence of post-cingulotomy behavioural adaptation reported in this study may have been due to practice effects. We run a control condition where we tested subjects before and after a dummy treatment, which substituted cingulotomy with a filler task (presentation of a documentary). The results revealed abolished behavioural adaptation following the dummy treatment. Our findings suggest that future work using proper experimental designs is needed to advance the understanding of the causal role of the MCC in behavioural adaptation.Action Contro

A model for adapting 3D graphics based on scalable coding, real-time simplification and remote rendering

Most current multiplayer 3D games can only be played on dedicated platforms, requiring specifically designed content and communication over a predefined network. To overcome these limitations, the OLGA (On-Line GAming) consortium has devised a framework to develop distributive, multiplayer 3D games. Scalability at the level of content, platforms and networks is exploited to achieve the best trade-offs between complexity and quality

Obesity is associated with impaired long-term success of pulmonary vein isolation:A plea for risk factor management before ablation

Aims: Obesity is an increasing health problem and is an important risk factor for the development of atrial fibrillation (AF). We investigated the association of body mass index (BMI) on the safety and long-term efficacy of pulmonary vein isolation (PVI) for drug-refractory AF. Methods: 414 consecutive patients who underwent transcatheter PVI for AF between 2003 and 2013 were included. Successful PVI was defined as absence of atrial arrhythmia on Holter monitoring or ECG, without and with antiarrhythmic drugs during follow-up. Obesity was defined as BMI≥30 kg/m². Results: Mean age was 56±10 years, 316 (76%) were male, 311 (75%) had paroxysmal AF and 111 (27%) were obese. After a mean follow-up of 46±32 months (1590 patient-years), freedom from atrial arrhythmia and antiarrhythmic drugs was significantly lower in patients with obesity compared with non-obese patients (30% vs 46%, respectively, P=0.005, log-rank 0.016). With antiarrhythmic drugs, freedom from atrial arrhythmia was 56% vs 68% (P=0.036). No differences in minor and major adverse events were observed between patients with obesity and non-obese patients (major 6% vs 3%, P=0.105, and minor 5% vs 5%, P=0.512). Sensitivity analyses demonstrated that BMI (as continuous variable) was associated with PVI outcome (HR 1.08, 95% CI 1.02 to 1.14, P=0.012). Conclusion: Obesity is associated with reduced efficacy of PVI for drug-refractory AF. No relation between obesity and adverse events was found

Incontinentia Pigmenti: Clinical Observation of 40 Korean Cases

Incontinentia pigmenti (IP) is an uncommon genodermatosis that usually occurs in female infants. It is characterized by ectodermal, mesodermal, neurological, ocular, and dental manifestations. The aim of this study was to clarify clinical symptoms, accompanying diseases, and complications of IP. Forty cases of IP have been reviewed by their medical records, laboratory data, clinical photographs, and telephone survey. Male-to-female ratio was 1 to 19 and their onsets were mostly in utero. They were usually diagnosed during the neonatal period owing to their early expression of skin manifestation. Central nervous system anomalies were found in 46.7%. Ocular disorders and dental defects were detected in 66.7% and 72.7% respectively. The most commonly diagnosed anomalies were hypodontia, retinopathy, and seizure. For better understanding of IP, long term and close cooperation between dermatologists, pediatricians, neuroscientists, genentic counselors, and even dentists is crucial

Development and psychometric evaluation of the Decision Tool Anxiety Disorders, OCD and PTSD (DTAOP):Facilitating the early detection of patients in need of highly specialized care

Background: Early identification of patients with an anxiety disorder, obsessive-compulsive disorder (OCD), or post-traumatic stress disorder (PTSD) in need of highly specialized care could facilitate the selection of the optimal initial treatment in these patients. This paper describes the development and psychometric evaluation of the Decision Tool Anxiety Disorders, OCD and PTSD (DTAOP), which aims to aid clinicians in the early identification of patients with an anxiety disorder, OCD, or PTSD in need of highly specialized mental healthcare. Methods: A systematic literature review and a concept mapping procedure were carried out to inform the development of the DTAOP. To evaluate the psychometric properties of the DTAOP, a cross-sectional study in 454 patients with a DSM-IV-TR anxiety disorder was carried out. Feasibility was evaluated by the completion time and the content clarity of the DTAOP. Inter-rater reliability was assessed in a subsample of 87 patients. Spearman’s rank correlation coefficients between the DTAOP and EuroQol five-dimensional questionnaire (EQ-5D-5L) scores were computed to examine the convergent validity. Criterion validity was assessed against independent clinical judgments made by clinicians. Results: The average time required to complete the eight-item DTAOP was 4.6 min and the total DTAOP was evaluated as clear in the majority (93%) of the evaluations. Krippendorff’s alpha estimates ranged from 0.427 to 0.839. Based on the qualitative feedback, item wording and instructions were improved. As hypothesized, the DTAOP correlated negatively with EQ-5D-5L scores. The area under the curve was 0.826 and the cut-off score of >= 4 optimized sensitivity (70%) and specificity (71%). Conclusions: The DTAOP demonstrated excellent feasibility and good validity, but weak inter-rater reliability. Based on the qualitative feedback and reliability estimates, revisions and refinements of the wording and instructions were made, resulting in the final version of the DTAOP