The Experts below are selected from a list of 153 Experts worldwide ranked by ideXlab platform
Mingsheng Ying - One of the best experts on this subject based on the ideXlab platform.
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Reasoning about Parallel Quantum Programs.
arXiv: Logic in Computer Science, 2018Co-Authors: Mingsheng Ying, Yangjia LiAbstract:We initiate the study of parallel Quantum Programming by defining the operational and denotational semantics of parallel Quantum Programs. The technical contributions of this paper include: (1) find a series of useful proof rules for reasoning about correctness of parallel Quantum Programs; and (2) prove a strong soundness theorem of these proof rules showing that partial correctness is well maintained at each step of transitions in the operational semantics of a parallel Quantum Program. This is achieved by partially overcoming the following conceptual challenges that are never present in classical parallel Programming: (i) the intertwining of nondeterminism caused by Quantum measurements and introduced by parallelism; (ii) entanglement between component Quantum Programs; and (iii) combining Quantum predicates in the overlap of state Hilbert spaces of component Quantum Programs with shared variables. It seems that a full solution to these challenges and developing a (relatively) complete proof system for parallel Quantum Programs are still far beyond the current reach.
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Algorithmic Analysis of Termination Problems for Quantum Programs
2018Co-Authors: Mingsheng YingAbstract:We introduce the notion of linear ranking super-martingale (LRSM) for Quantum Programs (with nondeterministic choices, namely angelic and demonic choices). Several termination theorems are established showing that the existence of the LRSMs of a Quantum Program implies its termination. Thus, the termination problems of Quantum Programs is reduced to realisability and synthesis of LRSMs. We further show that the realisability and synthesis problem of LRSMs for Quantum Programs can be reduced to an SDP (Semi-Definite Programming) problem, which can be settled with the existing SDP solvers. The techniques developed in this paper are used to analyse the termination of several example Quantum Programs, including Quantum random walks and Quantum Bernoulli factory for random number generation. This work is essentially a generalisation of constraint-based approach to the corresponding problems for probabilistic Programs developed in the recent literature by adding two novel ideas: (1) employing the fundamental Gleason’s theorem in Quantum mechanics to guide the choices of templates; and (2) a generalised Farkas’ lemma in terms of observables (Hermitian operators) in Quantum physics.
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Termination of nondeterministic Quantum Programs
Acta Informatica, 2013Co-Authors: Mingsheng YingAbstract:We define a language-independent model of nondeterministic Quantum Programs in which a Quantum Program consists of a finite set of Quantum processes. These processes are represented by Quantum Markov chains over the common state space, which formalize the Quantum mechanical behaviors of the machine. An execution of a nondeterministic Quantum Program is modeled by a sequence of actions of individual processes, and at each step of an execution a process is chosen nondeterministically to perform the next action. This execution model formalize the users' behavior of calling the processes in the classical world. Applying the model to a Quantum walk as an instance of physically realizable systems, we describe an execution step by step. A characterization of reachable space and a characterization of diverging states of a nondeterministic Quantum Program are presented. We establish a zero-one law for termination probability of the states in the reachable space. A combination of these results leads to a necessary and sufficient condition for termination of nondeterministic Quantum Programs. Based on this condition, an algorithm is found for checking termination of nondeterministic Quantum Programs within a fixed finite-dimensional state space.
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Termination of Nondeterministic Quantum Programs
arXiv: Logic in Computer Science, 2012Co-Authors: Yangjia Li, Nengkun Yu, Mingsheng YingAbstract:We define a language-independent model of nondeterministic Quantum Programs in which a Quantum Program consists of a finite set of Quantum processes. These processes are represented by Quantum Markov chains over the common state space. An execution of a nondeterministic Quantum Program is modeled by a sequence of actions of individual processes. These actions are described by super-operators on the state Hilbert space. At each step of an execution, a process is chosen nondeterministically to perform the next action. A characterization of reachable space and a characterization of diverging states of a nondeterministic Quantum Program are presented. We establish a zero-one law for termination probability of the states in the reachable space of a nondeterministic Quantum Program. A combination of these results leads to a necessary and sufficient condition for termination of nondeterministic Quantum Programs. Based on this condition, an algorithm is found for checking termination of nondeterministic Quantum Programs within a fixed finite-dimensional state space. A striking difference between nondeterministic classical and Quantum Programs is shown by example: it is possible that each of several Quantum Programs simulates the same classical Program which terminates with probability 1, but the nondeterministic Program consisting of them terminates with probability 0 due to the interference carried in the execution of them.
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Reachability and termination analysis of concurrent Quantum Programs
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2012Co-Authors: Nengkun Yu, Mingsheng YingAbstract:We introduce a Markov chain model of concurrent Quantum Programs. This model is a Quantum generalization of Hart, Sharir and Pnueli's probabilistic concurrent Programs. Some characterizations of the reachable space, uniformly repeatedly reachable space and termination of a concurrent Quantum Program are derived by the analysis of their mathematical structures. Based on these characterizations, algorithms for computing the reachable space and uniformly repeatedly reachable space and for deciding the termination are given.
Margaret Martonosi - One of the best experts on this subject based on the ideXlab platform.
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Statistical Assertions for Validating Patterns and Finding Bugs in Quantum Programs
Proceedings of the 46th International Symposium on Computer Architecture, 2019Co-Authors: Yipeng Huang, Margaret MartonosiAbstract:In support of the growing interest in Quantum computing experimentation, Programmers need new tools to write Quantum algorithms as Program code. Compared to debugging classical Programs, debugging Quantum Programs is difficult because Programmers have limited ability to probe the internal states of Quantum Programs; those states are difficult to interpret even when observations exist; and Programmers do not yet have guidelines for what to check for when building Quantum Programs. In this work, we present Quantum Program assertions based on statistical tests on classical observations. These allow Programmers to decide if a Quantum Program state matches its expected value in one of classical, superposition, or entangled types of states. We extend an existing Quantum Programming language with the ability to specify Quantum assertions, which our tool then checks in a Quantum Program simulator. We use these assertions to debug three benchmark Quantum Programs in factoring, search, and chemistry. We share what types of bugs are possible, and lay out a strategy for using Quantum Programming patterns to place assertions and prevent bugs.
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noise adaptive compiler mappings for noisy intermediate scale Quantum computers
Architectural Support for Programming Languages and Operating Systems, 2019Co-Authors: Prakash Murali, Frederic T. Chong, Jonathan M Baker, Ali Javadiabhari, Margaret MartonosiAbstract:A massive gap exists between current Quantum computing (QC) prototypes, and the size and scale required for many proposed QC algorithms. Current QC implementations are prone to noise and variability which affect their reliability, and yet with less than 80 Quantum bits (qubits) total, they are too resource-constrained to implement error correction. The term Noisy Intermediate-Scale Quantum (NISQ) refers to these current and near-term systems of 1000 qubits or less. Given NISQ's severe resource constraints, low reliability, and high variability in physical characteristics such as coherence time or error rates, it is of pressing importance to map computations onto them in ways that use resources efficiently and maximize the likelihood of successful runs. This paper proposes and evaluates backend compiler approaches to map and optimize high-level QC Programs to execute with high reliability on NISQ systems with diverse hardware characteristics. Our techniques all start from an LLVM intermediate representation of the Quantum Program (such as would be generated from high-level QC languages like Scaffold) and generate QC executables runnable on the IBM Q public QC machine. We then use this framework to implement and evaluate several optimal and heuristic mapping methods. These methods vary in how they account for the availability of dynamic machine calibration data, the relative importance of various noise parameters, the different possible routing strategies, and the relative importance of compile-time scalability versus runtime success. Using real-system measurements, we show that fine grained spatial and temporal variations in hardware parameters can be exploited to obtain an average 2.9x (and up to 18x) improvement in Program success rate over the industry standard IBM Qiskit compiler. Despite small qubit counts, NISQ systems will soon be large enough to demonstrate "Quantum supremacy", i.e., an advantage over classical computing. Tools like ours provide significant improvements in Program reliability and execution time, and offer high leverage in accelerating progress towards Quantum supremacy.
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ScaffCC: Scalable compilation and analysis of Quantum Programs
Parallel Computing, 2015Co-Authors: Ali Javadi-abhari, Shruti Patil, Daniel Kudrow, Jeff Heckey, Alexey Lvov, Frederic T. Chong, Margaret MartonosiAbstract:Abstract We present ScaffCC, a scalable compilation and analysis framework based on LLVM (Lattner and Adve, 2004), which can be used for compiling Quantum computing applications at the logical level. Drawing upon mature compiler technologies, we discuss similarities and differences between compilation of classical and Quantum Programs, and adapt our methods to optimizing the compilation time and output for the Quantum case. Our work also integrates a reversible-logic synthesis tool in the compiler to facilitate coding of Quantum circuits. Lastly, we present some useful Quantum Program analysis scenarios and discuss their implications, specifically with an elaborate discussion of timing analysis for critical path estimation. Our work focuses on bridging the gap between high-level Quantum algorithm specifications and low-level physical implementations, while providing good scalability to larger and more interesting problems.
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Deterministic error model for Quantum computer simulation
Physical Review A, 2008Co-Authors: Eric Chi, Stephen Aplin Lyon, Margaret MartonosiAbstract:Quantum computers QCs must implement Quantum error correcting codes QECCs to protect their logical qubits from errors, and modeling the effectiveness of QECCs on QCs is an important problem for evaluating the QC architecture. The previously developed Monte Carlo MC error models may take days or weeks of execution to produce an accurate result due to their random sampling approach. We present an alternative deterministic error model that generates, over the course of executing the Quantum Program, a probability tree of the QC’s error states. By calculating the fidelity of the Quantum Program directly, this error model has the potential for enormous speedups over the MC model when applied to small yet useful problem sizes containing on the order of a dozen logical qubits encoded in the 7,1,3 QECC plus associated ancilla. We observe a speedup on the order of 1000X when accuracy is required, and we evaluate the scaling properties of this new deterministic error model.
Neeloo Singh - One of the best experts on this subject based on the ideXlab platform.
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In Silico Screening, Structure-Activity Relationship, and Biologic Evaluation of Selective Pteridine Reductase Inhibitors Targeting Visceral Leishmaniasis
Antimicrobial Agents and Chemotherapy, 2010Co-Authors: Jaspreet Kaur, Pranav Kumar, Sargam Tyagi, Richa Pathak, Sanjay Batra, Prashant Singh, Neeloo SinghAbstract:In this study we utilized the concept of rational drug design to identify novel compounds with optimal selectivity, efficacy and safety, which would bind to the target enzyme pteridine reductase 1 (PTR1) in Leishmania parasites. Twelve compounds afforded from Baylis-Hillman chemistry were docked by using the Quantum Program into the active site of Leishmania donovani PTR1 homology model. The biological activity for these compounds was estimated in green fluorescent protein-transfected L. donovani promastigotes, and the most potential analogue was further investigated in intracellular amastigotes. Structure-activity relationship based on homology model drawn on our recombinant enzyme was substantiated by recombinant enzyme inhibition assay and growth of the cell culture. Flow cytometry results indicated that 7-(4-chlorobenzyl)-3-methyl-4-(4-trifluoromethyl-phenyl)-3,4,6,7,8,9-hexahydro-pyrimido[1,2-a]pyrimidin-2-one (compound 7) was 10 times more active on L. donovani amastigotes (50% inhibitory concentration [IC50] = 3 μM) than on promastigotes (IC50 = 29 μM). Compound 7 exhibited a Ki value of 0.72 μM in a recombinant enzyme inhibition assay. We discovered that novel pyrimido[1,2-a]pyrimidin-2-one systems generated from the allyl amines afforded from the Baylis-Hillman acetates could have potential as a valuable pharmacological tool against the neglected disease visceral leishmaniasis.
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Molecular docking, structure–activity relationship and biological evaluation of the anticancer drug monastrol as a pteridine reductase inhibitor in a clinical isolate of Leishmania donovani
Journal of Antimicrobial Chemotherapy, 2010Co-Authors: Jaspreet Kaur, Shyam Sundar, Neeloo SinghAbstract:Methods: Monastrol (R) and (S) enantiomers were docked using the Quantum Program into the active site of a Leishmania donovani PTR1 (LdPTR1) homology model. A structure‐activity relationship based on a homology model of a recombinant enzyme was substantiated by a recombinant enzyme inhibition assay. We adapted an L. donovani (transfected with green fluorescent protein) intramacrophage amastigote screening assay as a cellular model for leishmaniasis. Furthermore, since the clinicopathological features and immunopathological mechanisms of visceral leishmaniasis (VL) in a hamster model are remarkably similar to those of human disease, systemic infection of hamsters with L. donovani was utilized to collect in vivo data for monastrol. Results: Both monastrol (R) and (S) enantiomers fit well in the ligand-binding pocket of LdPTR1. Monastrol exhibits a Ki value of 0.428 mM in the recombinant enzyme inhibition assay. We confirm monastrol as a potent inhibitor of PTR1 in Leishmania; it inhibits proliferation of amastigotes with an IC50 (50% inhibitory concentration) of 10 mM in macrophage cultures infected with an L. donovani clinical isolate, with no host cytotoxicity. We also show that in experimental animals, oral administration of a 5 mg/kg dose of monastrol on two alternate days inhibits 50% of parasite growth, giving therapeutic backing to the use of monastrol as a potent antileishmanial in human VL cases.
Leihai Nie - One of the best experts on this subject based on the ideXlab platform.
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Optimizing Quantum Programs against Decoherence: Delaying Qubits into Quantum Superposition
2019 International Symposium on Theoretical Aspects of Software Engineering (TASE), 2019Co-Authors: Yu Zhang, Haowei Deng, Haoze Song, Leihai NieAbstract:Quantum computing technology has reached a second renaissance in the last decade. However, in the NISQ era pointed out by John Preskill in 2018, Quantum noise and decoherence, which affect the accuracy and execution effect of Quantum Programs, cannot be ignored and corrected by the near future NISQ computers. In order to let users more easily write Quantum Programs, the compiler and runtime system should consider underlying Quantum hardware features such as decoherence. To address the challenges posed by decoherence, in this paper, we propose and prototype QLifeReducer to minimize the qubit lifetime in the input OpenQASM Program by delaying qubits into Quantum superposition. QLifeReducer includes three core modules, i.e.,the parser, parallelism analyzer and transformer. It introduces the layered bundle format to express the Quantum Program, where a set of parallelizable Quantum operations is packaged into a bundle. We evaluate Quantum Programs before and after transformed by QLifeReducer on both real IBM Q 5 Tenerife and the self-developed simulator. The experimental results show that QLifeReducer reduces the error rate of a Quantum Program when executed on IBMQ 5 Tenerife by 11%; and can reduce the longest qubit lifetime as well as average qubit lifetime by more than 20% on most Quantum workloads.
Jaspreet Kaur - One of the best experts on this subject based on the ideXlab platform.
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In Silico Screening, Structure-Activity Relationship, and Biologic Evaluation of Selective Pteridine Reductase Inhibitors Targeting Visceral Leishmaniasis
Antimicrobial Agents and Chemotherapy, 2010Co-Authors: Jaspreet Kaur, Pranav Kumar, Sargam Tyagi, Richa Pathak, Sanjay Batra, Prashant Singh, Neeloo SinghAbstract:In this study we utilized the concept of rational drug design to identify novel compounds with optimal selectivity, efficacy and safety, which would bind to the target enzyme pteridine reductase 1 (PTR1) in Leishmania parasites. Twelve compounds afforded from Baylis-Hillman chemistry were docked by using the Quantum Program into the active site of Leishmania donovani PTR1 homology model. The biological activity for these compounds was estimated in green fluorescent protein-transfected L. donovani promastigotes, and the most potential analogue was further investigated in intracellular amastigotes. Structure-activity relationship based on homology model drawn on our recombinant enzyme was substantiated by recombinant enzyme inhibition assay and growth of the cell culture. Flow cytometry results indicated that 7-(4-chlorobenzyl)-3-methyl-4-(4-trifluoromethyl-phenyl)-3,4,6,7,8,9-hexahydro-pyrimido[1,2-a]pyrimidin-2-one (compound 7) was 10 times more active on L. donovani amastigotes (50% inhibitory concentration [IC50] = 3 μM) than on promastigotes (IC50 = 29 μM). Compound 7 exhibited a Ki value of 0.72 μM in a recombinant enzyme inhibition assay. We discovered that novel pyrimido[1,2-a]pyrimidin-2-one systems generated from the allyl amines afforded from the Baylis-Hillman acetates could have potential as a valuable pharmacological tool against the neglected disease visceral leishmaniasis.
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Molecular docking, structure–activity relationship and biological evaluation of the anticancer drug monastrol as a pteridine reductase inhibitor in a clinical isolate of Leishmania donovani
Journal of Antimicrobial Chemotherapy, 2010Co-Authors: Jaspreet Kaur, Shyam Sundar, Neeloo SinghAbstract:Methods: Monastrol (R) and (S) enantiomers were docked using the Quantum Program into the active site of a Leishmania donovani PTR1 (LdPTR1) homology model. A structure‐activity relationship based on a homology model of a recombinant enzyme was substantiated by a recombinant enzyme inhibition assay. We adapted an L. donovani (transfected with green fluorescent protein) intramacrophage amastigote screening assay as a cellular model for leishmaniasis. Furthermore, since the clinicopathological features and immunopathological mechanisms of visceral leishmaniasis (VL) in a hamster model are remarkably similar to those of human disease, systemic infection of hamsters with L. donovani was utilized to collect in vivo data for monastrol. Results: Both monastrol (R) and (S) enantiomers fit well in the ligand-binding pocket of LdPTR1. Monastrol exhibits a Ki value of 0.428 mM in the recombinant enzyme inhibition assay. We confirm monastrol as a potent inhibitor of PTR1 in Leishmania; it inhibits proliferation of amastigotes with an IC50 (50% inhibitory concentration) of 10 mM in macrophage cultures infected with an L. donovani clinical isolate, with no host cytotoxicity. We also show that in experimental animals, oral administration of a 5 mg/kg dose of monastrol on two alternate days inhibits 50% of parasite growth, giving therapeutic backing to the use of monastrol as a potent antileishmanial in human VL cases.
