Locality Induced Non-Universality for Abelian Symmetries

According to a well-known result in quantum computing, any unitary transformation on a composite system can be generated using $2$-local unitaries. Interestingly, this universality need not hold in the presence of symmetries. In this paper, we study the analogues of the non-universality results for all Abelian symmetries.Comment: 11 pages, 1 table, 0 figure

QIP = PSPACE

We prove that the complexity class QIP, which consists of all problems having quantum interactive proof systems, is contained in PSPACE. This containment is proved by applying a parallelized form of the matrix multiplicative weights update method to a class of semidefinite programs that captures the computational power of quantum interactive proofs. As the containment of PSPACE in QIP follows immediately from the well-known equality IP = PSPACE, the equality QIP = PSPACE follows.Comment: 21 pages; v2 includes corrections and minor revision

An anthropometric study of intercondylar femur notch with MRI analysis

Background: Anterior cruciate ligament is the most common ligament injury of knee. The bony anatomy of femur and tibia is responsible for normal knee kinematics and static stability. Intercondylar notch dimensions is considered as a significant predictive risk factor for ACL tear. Narrow femoral intercondylar notch width in either sex were major correlating factors. Aim was to evaluate the intercondylar femur notch dimensions in patients of knee injury using magnetic resonance imaging at RD Gardi Medical College, Ujjain, Madhya Pradesh. Methods: This is a prospective study consist of 400 patients carried out from October 2020 to August 2022 in the Department of Orthopaedics, RDGMC Ujjain. All the patients of knee injury including ACL tear and age 18 years to 60 years are included in the study. Patient less than 18 years and more than 60 years were excluded from the study. Dicom radiant software is used as statistical tool to analyse the data. Various intercondylar notch dimensions in different sections are measured using MRI in the dicom software. Results: The cut off values of axial NWI, NSI, NDI as 0.238, 0.662, 0.472 respectively. Conclusions: We conclude that narrow femoral intercondylar notch, lower notch width index increases the risk of an ACL tear in the given population. This would help in identification of people at risk for ACL injuries. Our study provides a comprehensive analysis on the risk factor of ACL tear, which would help in betterment of the patients at danger for anterior cruciate ligament injury. People with decreased notch dimensions should be educated on the high risk of ACL tear and be given proper prophylactic precautions

Tactile Sensing over Articulated Joints with Stretchable Sensors

©2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.Presented at the World Haptics Conference (WHC), 2013, 14-17 April 2013.DOI: 10.1109/WHC.2013.6548392Biological organisms benefit from tactile sensing across the entire surfaces of their bodies. Robots may also be able to benefit from this type of sensing, but fully covering a robot with robust and capable tactile sensors entails numerous challenges. To date, most tactile sensors for robots have been used to cover rigid surfaces. In this paper, we focus on the challenge of tactile sensing across articulated joints, which requires sensing across a surface whose geometry varies over time. We first demonstrate the importance of sensing across joints by simulating a planar arm reaching in clutter and finding the frequency of contact at the joints. We then present a simple model of how much a tactile sensor would need to stretch in order to cover a 2 degree-of-freedom (DoF) wrist joint. Next, we describe and characterize a new tactile sensor made with stretchable fabrics. Finally, we present results for a stretchable sleeve with 25 tactile sensors that covers the forearm, 2 DoF wrist, and end effector of a humanoid robot. This sleeve enabled the robot to reach a target in instrumented clutter and reduce contact forces

qip = pspace

ACM Special Interest Group on Algorithms and Computation Theory; SIGACTWe prove that the complexity class QIP, which consists of all problems having quantum interactive proof systems, is contained in PSPACE. This containment is proved by applying a parallelized form of the matrix multiplicative weights update method to a class of semidefinite programs that captures the computational power of quantum interactive proofs. As the containment of PSPACE in QIP follows immediately from the well-known equality IP = PSPACE, the equality QIP = PSPACE follows. © 2010 ACM

Whole-arm Tactile Sensing for Beneficial and Acceptable Contact During Robotic Assistance

©2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.Presented at the IEEE International Conference on Rehabilitation Robotics (ICORR) 24-26 June 2013.DOI: 10.1109/ICORR.2013.6650464Many assistive tasks involve manipulation near the care-receiver's body, including self-care tasks such as dressing, feeding, and personal hygiene. A robot can provide assistance with these tasks by moving its end effector to poses near the care-receiver's body. However, perceiving and maneuvering around the care-receiver's body can be challenging due to a variety of issues, including convoluted geometry, compliant materials, body motion, hidden surfaces, and the object upon which the body is resting (e.g., a wheelchair or bed). Using geometric simulations, we first show that an assistive robot can achieve a much larger percentage of end-effector poses near the care-receiver's body if its arm is allowed to make contact. Second, we present a novel system with a custom controller and whole-arm tactile sensor array that enables a Willow Garage PR2 to regulate contact forces across its entire arm while moving its end effector to a commanded pose. We then describe tests with two people with motor impairments, one of whom used the system to grasp and pull a blanket over himself and to grab a cloth and wipe his face, all while in bed at his home. Finally, we describe a study with eight able-bodied users in which they used the system to place objects near their bodies. On average, users perceived the system to be safe and comfortable, even though substantial contact occurred between the robot's arm and the user's body