178 research outputs found

    Optimizing Quantum Programs against Decoherence: Delaying Qubits into Quantum Superposition

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    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.Comment: To appear in TASE2019 - the 13th International Symposium on Theoretical Aspects of Software Engineering (submitted on Jan 25, 2019, and this is camera-ready version

    CODAR: A Contextual Duration-Aware Qubit Mapping for Various NISQ Devices

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    Quantum computing devices in the NISQ era share common features and challenges like limited connectivity between qubits. Since two-qubit gates are allowed on limited qubit pairs, quantum compilers must transform original quantum programs to fit the hardware constraints. Previous works on qubit mapping assume different gates have the same execution duration, which limits them to explore the parallelism from the program. To address this drawback, we propose a Multi-architecture Adaptive Quantum Abstract Machine (maQAM) and a COntext-sensitive and Duration-Aware Remapping algorithm (CODAR). The CODAR remapper is aware of gate duration difference and program context, enabling it to extract more parallelism from programs and speed up the quantum programs by 1.23 in simulation on average in different architectures and maintain the fidelity of circuits when running on Origin Quantum noisy simulator.Comment: arXiv admin note: substantial text overlap with arXiv:2001.0688

    Obstacles Facing the Development of MIS in the River Nile State (RNS) Public Sector – Sudan

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    This study investigated and identified the obstacles facing the development of MIS in the RNS. In addition, it checks out the existence, importance and the employment of MIS in the RNS. The study applied the descriptive research design of survey type. Data were collected from a sample of 221 reflects the employees in some RNS ministries holding different job positions using stratified random sampling technique. Data collected were analyzed using frequencies count, percentages and chi square test statistics. The study revealed that MIS was not adequately employed in the RNS institutions. Therefore, it confirmed that MIS was very important to improve the management performance. The study showed that MIS was not adequately used for formulating policies and strategies in the state institutions. The study identified several obstacles facing the development of MIS in the RNS. It was recommended that proper orientation should be given to MIS development in the state. Also, training programs should be organized to ensure proper and adequate employment of MIS in generating and disseminating information. Furthermore, the RNS government should set up unified information technology policy to enable all the state institutions to obtain information required with in specific standards and criteria. Keywords: Management information systems (MIS)    MIS obstacles   MIS development River Nile State (RNS

    Chronic exposure to Bisphenol A impairs progesterone receptor-mediated signaling in the uterus during early pregnancy

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    Environmental and occupational exposure to endocrine disrupting chemicals (EDCs) is a major threat to female reproductive health. Bisphenol A (BPA), an environmental toxicant that is commonly found in polycarbonate plastics and epoxy resins, has received much attention due to its estrogenic activity and high risk of chronic exposure in human. Whereas BPA has been linked to infertility and recurrent miscarriage in women, the impact of its exposure on uterine function during early pregnancy remains unclear. In a recent publication in Endocrinology, we demonstrated that prolonged exposure to an environmental relevant dose of BPA disrupts progesterone receptor-regulated uterine functions, thus affecting uterine receptivity for embryo implantation and decidua morphogenesis, two critical events for establishment and maintenance of early pregnancy. In particular we reported a marked impairment of progesterone receptor (PGR) expression and its downstream effector HAND2 in the uterine stromal cells in response to chronic BPA exposure. In an earlier study we have shown that HAND2 controls embryo implantation by repressing fibroblast growth factor (FGF) expression and the MAP kinase signaling pathway, thus inhibiting epithelial proliferation. Interestingly we observed that downregulation of PGR and HAND2 expression in uterine stroma upon BPA exposure was associated with an enhanced activation of FGFR and MAPK signaling, aberrant proliferation, and lack of uterine receptivity in the epithelium. In addition, the proliferation and differentiation of endometrial stromal cells to decidual cells, an event critical for the maintenance of early pregnancy, was severely compromised in response to BPA. This research highlight will provide an overview of our findings and discuss the potential mechanisms by which chronic BPA impairs PGR-HAND2 pathway and adversely affects implantation and the establishment of pregnancy

    Antiperovskite Li3OCl Superionic Conductor Films for Solid-State Li-Ion Batteries.

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    Antiperovskite Li3OCl superionic conductor films are prepared via pulsed laser deposition using a composite target. A significantly enhanced ionic conductivity of 2.0 × 10-4 S cm-1 at room temperature is achieved, and this value is more than two orders of magnitude higher than that of its bulk counterpart. The applicability of Li3OCl as a solid electrolyte for Li-ion batteries is demonstrated

    Reducing Leakage Current and Enhancing Polarization in Multiferroic 3D Super-nanocomposites by Microstructure Engineering

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    Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4 (CFO) short nanopillar arrays embedded in BaTiO3 (BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows encapsulating the relative conducting CFO phase by the insulating BTO phase, which suppress the leakage current and enhance the polarization. Our results demonstrate that microstructure engineering in 3D‐sNC offers a new bottom–up method of fabricating advanced nanostructures with a wide range of possible configurations for applications where the functional properties need to be systematically modified

    Quality Control in Weather Monitoring with Dynamic Linear Models

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    Decisions in agriculture are frequently based on weather. With an increase in the availability and affordability of off-the-shelf weather stations, farmers able to acquire localised weather information. However, with uncertainty in the sensor and installation quality, farmers are at risk of making poor decisions based on incorrect data. We present an automated approach to perform quality control on weather sensors. Our approach uses time-series modelling and data fusion with Bayesian principles to provide predictions with uncertainty quantification. These predictions and uncertainty are used to estimate the validity of a sensor observation. We test on temperature, wind, and humidity data and achieve error hit rates above 80% and false negative rates below 11%

    Research on the ablation characteristics of combined lasers for glass fiber reinforced plastic composites

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    Glass fiber reinforced plastic (GFRP) composites have been applied to the manufacture of missile shields and unmanned aerial vehicle (UAV) shells. It is of great significance to explore the ablation characteristics of different lasers for these composites. Currently, most existing studies on the ablation characteristics of lasers for Glass fiber reinforced plastic composites are conducted under a single laser output mode, such as continuous wave (CW) laser or pulsed laser. However, the ablation characteristics of combined lasers for Glass fiber reinforced plastic composites have not been clarified. Therefore, the ablation characteristics of single lasers (continuous wave, millisecond (ms) pulsed, or nanosecond (ns) pulsed laser) and combined laser (CW/ms or CW/ns combined pulsed lasers) were investigated by experimental and simulation methods in this study. Additionally, the ablation mechanisms of Glass fiber reinforced plastic under different laser irradiation conditions were compared and analyzed. The results demonstrated that the ablation rates of single lasers for Glass fiber reinforced plastic composites were all within an order of magnitude of 10 Όg/J, which was not significantly correlated with the light source system. The ablation efficiency of the single laser was determined by the incident laser energy. The continuous wave laser was found to be the optimal light source for the ablation and destruction of Glass fiber reinforced plastic composites. Nevertheless, there were some obstacles in the ablation process of continuous wave lasers. Applying pulsed lasers during the irradiation of the continuous wave laser may generate a synergistic effect. Under the conditions in this study, the CW/ns pulsed combined laser increased the ablation efficiency by 53.8%
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