110 research outputs found

    Sequential Principal-Agent Problems with Communication: Efficient Computation and Learning

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    We study a sequential decision making problem between a principal and anagent with incomplete information on both sides. In this model, the principaland the agent interact in a stochastic environment, and each is privy toobservations about the state not available to the other. The principal has thepower of commitment, both to elicit information from the agent and to providesignals about her own information. The principal and the agent communicatetheir signals to each other, and select their actions independently based onthis communication. Each player receives a payoff based on the state and theirjoint actions, and the environment moves to a new state. The interactioncontinues over a finite time horizon, and both players act to optimize theirown total payoffs over the horizon. Our model encompasses as special casesstochastic games of incomplete information and POMDPs, as well as sequentialBayesian persuasion and mechanism design problems. We study both computation ofoptimal policies and learning in our setting. While the general problems arecomputationally intractable, we study algorithmic solutions under a conditionalindependence assumption on the underlying state-observation distributions. Wepresent an polynomial-time algorithm to compute the principal's optimal policyup to an additive approximation. Additionally, we show an efficient learningalgorithm in the case where the transition probabilities are not knownbeforehand. The algorithm guarantees sublinear regret for both players.<br

    CONTINUOUS BIM ALIGNMENT FOR MIXED REALITY VISUALISATION

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    Several methods exist that can be used to perform initial alignment of Building information models (BIMs) to the real building for Mixed Reality (MR) applications, such as marker-based or markerless visual methods, but this alignment is susceptible to drift over time. The existing model-based methods that can be used to maintain this alignment have multiple limitations, such as the use of iterative processes and poor performance in environments with either too many or not enough lines. To address these issues, we propose an end-to-end trainable Convolutional Neural Network (CNN) that takes a real and synthetic BIM image pair as input to regress the 6 DoF relative camera pose difference between them directly. By correcting the relative pose error we are able to considerably improve the alignment of the BIM to the real building. Furthermore, the results of our experiments demonstrate good performance in a challenging environment and high resilience to domain shift between synthetic and real images. A high localisation accuracy of approximately 7.0 cm and 0.9&deg; is achieved which indicates the method can be used to reduce the camera tracking drift for MR applications

    The Applicability of Provocative Functional Tests in the Diagnosis of Rotator Cuff Muscle Injuries of the Best University Athletes

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    Rotator cuff disease, external and internal impingement syndromes, low shoulder stability, various types of trauma, and overuse injuries are all related to sports activities. In order to check symptoms in patients with disability and shoulder pain, clinicians use different methods and diagnostic imaging assessment. The research is aimed at evaluating whether there is a difference between provocation function tests (PFT) and ultrasonographic (US) testing of muscles within the rotator cuff in elite collegiate athletes. Patients (n=184) were recruited from university team sports selections and tested with a standardized US examination of the shoulder and five PFTs (Speed's test, Neer's test, Hawkins test, lift-off test, Yergason's test). Based on the VAS pain assessment scale, 60 subjects had some pain, which was taken for further processing in the work (124 subjects did not have the presence of pain and were excluded from further processing). The US examination was conducted using Voluson 730 apparatus, by a linear probe, with the frequency in the range of 6-12 MHz. The chi-square test showed significant differences between PFT and the occurrence of shoulder muscle tendinitis for the following variables: Speed's test and subscapularis tendinitis (p=0.02) and Speed's test and infraspinatus tendinitis (p=0.01); Neer test and biceps brachii caput longum tendinitis (p=0.01), Neer test and supraspinatus tendinitis (p=0.02) and Neer test and infraspinatus tendinitis (p=0.01); lift-off test and subscapularis tendinitis (p=0.05); and Yergason's test and biceps brachii caput longum tendinitis (p=0.03) and Yergason's test and subscapitis tendinitis (p=0.01). The greatest effect of differences was observed in Neer's test and biceps brachii caput longum tendinitis (ϕ=0.60), while the other effects can be described as medium and small in most cases. It can be concluded that functional tests are good predictors of soft tissue changes in the muscles of the rotator cuff of the shoulder. Further monitoring and analysis are needed on a larger number of athletes

    Prirodna radioaktivnost uglja i letećeg pepela u termoelektrani 'Nikola Tesla B'

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    Serbian thermal power plants (TPPs) produce Siliceous fly ash from lignite in the quantity of approximately 6 million tons per year. The Potential. Market for the use of fly ash is operational, but for the time being, only Used by cement producers. Fly ash radioactivity could be one of the major points of concern When larger use of fly ash is planned, particularly in the Serbian construction industry. Radioactivity measurements have been conducted regularly from 1980. This paper presents the results of a ten-year fly ash radioactivity measurements at the Nikola Tesla B TPP located in Obrenovac. In addition, the paper compares the natural radionuclides coal content data combusted by the Nikola Tesla B TPP boilers coming from the Kolubara Basin and ash created during coal combustion. Fly ash created in the Nikola Tesla TPPs boilers is characterised by the increased concentration of the natural radionuclides content compared to coal. This is the so-called technologically enhanced natural radioactivity (Technologically Enhanced Occurring Radioactive Material - TENORM) of industrial waste, whereas the average specific activities: Th-232 in coal amount to 25.2 Bq/kg, and in fly ash and coal 84.2 Bq/kg and U-238 38.3 Bq/kg, respectively. Following the obtained natural radionuclides content results it may be concluded that the Nikola Tesla B TPP ash may be disposed into the environment. Ash may be used also in the construction industry (civil engineering). In building construction applications, ash share as the additive to other building materials depends from its physical and chemical characteristics, as well as from the radionuclides activity: Ra-226, Th-232 and K-40. Unlike the thermal power plants regularly (once a year) testing the specific natural radionuclides activity in the combusted coal and boiler fly ash, the Electric Power Industry of Serbia has not performed large-scale investigations of the natural radionuclides content in coal within the Kolubara Mining Basin. Natural radionuclides content in fly ash is compared to the combusted coal some 3-4 times higher and may present a limitation for applying ash in the construction industry. In view of the above, and considering the construction industry interests in using the Nikola Tesla B TPP ash, regular investigations of the natural radionuclides content in ash created in the thermal power plants should be carried out, together with the Kolubara Mining Basin coal combusted by the Nikola Tesla B TPP and other PE EPS thermal power plants. The current Kolubara Mining Basin coal characteristics investigation programme should be supplemented by the natural radionuclides content of the uranium (U-238 and Ra-226) and thorium series (Th-232) and potassium 40(K-40).U termoelektranama (TE) Javnog preduzeća 'Elektroprivreda Srbije' (JP EPS) koje u kotlovima sagorevaju lignit, kao nus produkat nastaje godišnje oko 6 miliona tona letećeg pepela. Potencijalno tržište za upotrebu letećeg pepela postoji, ali ga za sada koriste isključivo cementare. Radioaktivnost letećeg pepela može da predstavlja jedan od važnih razloga protiv njegove šire upotrebe u građevinskoj industriji Srbije. Merenje radioaktivnosti u termoelektranama redovno se sprovodi od 1990. godine. U radu su prikazani rezultati dvadesetogodišnjih merenja radioaktivnosti letećeg pepela u termoelektrani Nikola Tesla B (TENT B) u Obrenovcu. Uporedno su prikazani podaci o sadržaju prirodnih radionuklida u uglju koji se sagoreva u kotlovima TENT B poreklom iz kolubarskog basena i pepelu koji nastaje prilikom sagorevanja uglja. Na osnovu dobijenih rezultata o sadržaju prirodnih radionuklida zaključuje se da se pepeo iz termoelektrane Nikola Tesla B može odlagati u životnu sredinu. Pepeo se može koristiti i u građevinarstvu, u niskogradnji. Kod primene u visokoj gradnji udeo pepela kao dodataka drugim građevinskim materijalima zavisi kako od njegovih fizičkih i hemijskih karakteristika, tako i od specifične aktivnosti 226Ra, 232Th i 40K

    Target Engagement and Immunogenicity of an Active Immunotherapeutic Targeting Pathological α-Synuclein: A Phase 1 Placebo-Controlled Trial

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    Investigational therapeutics that target toxic species of α-synuclein (αSyn) aim to slow down or halt disease progression in patients with Parkinson\u27s disease (PD). Here this 44-week, randomized, placebo-controlled, double-blind, single-center phase 1 study investigated safety, tolerability and immunogenicity of UB-312, an active immunotherapeutic targeting pathological αSyn, in patients with PD. The primary outcome measures were adverse event frequency and change in anti-αSyn antibody titers in blood and cerebrospinal fluid (CSF). Exploratory outcomes were changes in clinical scales and biomarker-based target engagement as measured by seed amplification assays. Twenty patients were randomized 7:3 (UB-312:placebo) into 300/100/100 μg or 300/300/300 μg (weeks 1, 5 and 13) intramuscular prime-boost dose groups. Safety was similar across groups; adverse events were mostly mild and transient. Two patients experienced three serious adverse events in total, one possibly treatment related; all resolved without sequalae. Anti-αSyn antibodies in serum from 12/13 and CSF from 5/13 patients who received three UB-312 doses confirmed immunogenicity. Mean serum titers (in log-dilution factor) increased from baseline by 1.398 and 1.354, and peaked at week 29 at 2.520 and 2.133, for 300/100/100 μg and 300/300/300 μg, respectively. CSF titers were 0 at baseline and were 0.182 and 0.032 at week 21, respectively. Exploratory analyses showed no statistical differences in clinical scales but a significant reduction of αSyn seeds in CSF of a subset of UB-312-treated patients. These data support further UB-312 development. ClinicalTrials.gov:NCT04075318.

    The incidence of smoking and risk factors for smoking initiation in medical faculty students: cohort study

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    BACKGROUND: Medical education requires detailed investigation because it is a period during which the attitudes and behaviors of physicians develop. The purpose of this study was to calculate the yearly smoking prevalence and incidence rates of medical faculty students and to identify the risk factors for adopting smoking behaviour. METHODS: This is a cohort study in which every student was asked about their smoking habits at the time of first registration to the medical faculty, and was monitored every year. Smoking prevalence, yearly incidence of initiation of smoking and average years of smoking were calculated in analysis. RESULTS: At the time of registration, 21.8% of the students smoked. At the end of six years, males had smoked for an average of 2.6 ± 3.0 years and females for 1.0 ± 1.8 years (p < 0.05). Of the 93 medical students who were not smokers at the time of registration, 30 (32.3%) were smokers at the end of the 6 years of the course. CONCLUSION: The first 3 years of medical education are the most risky period for initiation of smoking. We found that factors such as being male, having a smoking friend in the same environment and having a high trait anxiety score were related to the initiation of smoking. Targeted smoking training should be mandatory for students in the Medical Faculty
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