LEARNABLE MASKS FOR POSE-GUIDED VIEW SYNTHESIS

Pose-guided human view synthesis uses a target pose to generate the appearance of a new view of a person. The input view and the target pose can be processed separately with UNet architectures that combine the results in a late fusion stage. UNet architectures link their encoder and decoder with skip connections that preserve the location of spatial features by injecting input information in the decoding process. However, direct skip connections may transfer irrelevant information to the decoder. We overcome this limitation with learnable masks for skip connections that encourage the decoder to use only relevant information from the encoder. We show that adding the proposed mask to UNet architectures improves the performance of view synthesis with only a slight increase in inference time

Distributed Formal Concept Analysis Algorithms Based on an Iterative MapReduce Framework

While many existing formal concept analysis algorithms are efficient, they are typically unsuitable for distributed implementation. Taking the MapReduce (MR) framework as our inspiration we introduce a distributed approach for performing formal concept mining. Our method has its novelty in that we use a light-weight MapReduce runtime called Twister which is better suited to iterative algorithms than recent distributed approaches. First, we describe the theoretical foundations underpinning our distributed formal concept analysis approach. Second, we provide a representative exemplar of how a classic centralized algorithm can be implemented in a distributed fashion using our methodology: we modify Ganter's classic algorithm by introducing a family of MR* algorithms, namely MRGanter and MRGanter+ where the prefix denotes the algorithm's lineage. To evaluate the factors that impact distributed algorithm performance, we compare our MR* algorithms with the state-of-the-art. Experiments conducted on real datasets demonstrate that MRGanter+ is efficient, scalable and an appealing algorithm for distributed problems.Comment: 17 pages, ICFCA 201, Formal Concept Analysis 201

Effects of Oxygen Vacancy Defect on Magnetic Properties of (Ca,Mn)O Doped System

We study the (Ca, Mn)O doped system with oxygen vacancy point defects in monoxide CaO material. Using density functional theory calculation based on a generalized gradient approximation, we show that such a defect can convert the ground state from a spin glass to a ferromagnetic phase. Then, we discuss the stability of the magnetism in the (Ca, Mn)O doped system. The ferromagnetic and the disordered local moment states are also investigated and a super-exchange mechanism is proposed to explain such ferromagnetic magnetic behaviours. Based on the mean field approximation used in the elaboration of the Heisenberg model, we estimate the Curie temperature

Return to sport and re-tears after anterior cruciate ligament reconstruction in children and adolescents

BACKGROUND: The primary objective of this study was to determine the time to and level of return to sports after anterior cruciate ligament (ACL) reconstruction in children and adolescents. The secondary objectives were to evaluate the risk of early ACL re-tear after return to sports and the risk of ACL tear in the contralateral knee. HYPOTHESIS: The time to return to sports in young patients is considerably longer than in adults. METHODS: A prospective multicentre study was conducted at 12 centres specialised in knee ligament surgery, in children and adolescents younger than 18 years, between 1 January 2015 and 31 October 2015. The patients were divided into a paediatric group with open physes and a skeletally mature group with closed physes. We recorded the time to return to sport, the type of sport resumed, and the occurrence of early re-tears on the same side. A poor outcome was defined as a re-tear or an objective IKDC score of C or D. A contralateral ACL tear was not considered a poor outcome. RESULTS: Of 278 included patients, 100 had open physes and 178 closed physes. In the open physes group, return to running occurred after 10.4±4.7 months, return to pivoting/contact sport training after 13.1±3.9 months, and return to pivoting/contact sport competitions after 13.8±3.8 months. Of the 100 patients, 80% returned to the same sport and 63.5% to pivoting/contact sport competitions. Re-tears occurred in 9% of patients, after 11.8±4.1 months, and contralateral tears in 6% of patients, after 17.2±4.4 months. In all, 19.4% of patients had a poor outcome, including 10.4% with an IKDC score of C or D and 9% with re-tears. In the group with closed physes, return to running occurred after 8.8±5.1 months, return to pivoting/contact sport training after 11.7±4.7 months, and return to pivoting/contact sport competitions after 12.3±4.2 months. Of the 178 patients, 76.9% returned to the same sport and 55.6% to pivoting/contact sport competitions. The re-tear rate was only 2.8% and the contralateral tear rate 5%. In all, 14.7% of patients had poor outcome, including 11.9% with an IKDC score of C or D and 2.8% with re-tears. No risk factors for re-tears were identified; the quadruple-bundle semitendinosus technique showed a non-significant association with re-tears. CONCLUSION: In young children, the return to sport time after ACL reconstruction is considerably longer than 1 year and the return to competitions occurs later and is more difficult. The results of this study indicate that reservations are in order when informing the family about return to sports prospects after ACL reconstruction. The return to pivoting/contact sport competitions should not be allowed until 14 months after surgery in young skeletally immature patients, and the risk of re-injury is high within the first 2 years. LEVEL OF EVIDENCE: IV, retrospective study