QCOR Mintz, Tiffany M.; McCaskey, Alexander J.; Dumitrescu, Eugene F. ...
ACM journal on emerging technologies in computing systems,
04/2020, Letnik:
16, Številka:
2
Journal Article
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Quantum computing (QC) is an emerging computational paradigm that leverages the laws of quantum mechanics to perform elementary logic operations. Existing programming models for QC were designed with ...fault-tolerant hardware in mind, envisioning stand-alone applications. However, the susceptibility of near-term quantum computers to noise limits their stand-alone utility. To better leverage limited computational strengths of noisy quantum devices, hybrid algorithms have been suggested whereby quantum computers are used in tandem with their classical counterparts in a heterogeneous fashion. This
modus operandi
calls out for a programming model and a high-level programming language that natively and seamlessly supports heterogeneous quantum-classical hardware architectures in a single-source-code paradigm. Motivated by the lack of such a model, we introduce a language extension specification, called
QCOR
, which enables single-source quantum-classical programming. Programs written using the QCOR library–based language extensions can be compiled to produce functional hybrid binary executables. After defining QCOR’s programming model, memory model, and execution model, we discuss how QCOR enables variational, iterative, and feed-forward QC. QCOR approaches quantum-classical computation in a hardware-agnostic heterogeneous fashion and strives to build on best practices of high-performance computing. The high level of abstraction in the language extension is intended to accelerate the adoption of QC by researchers familiar with classical high-performance computing.
Malignant bowel obstruction (MBO) is common in advanced GI cancer, and MBO management, including drainage percutaneous endoscopic gastrostomy (dPEG), is palliative. How patients understand the goals ...of dPEG and its impact on disease is inadequately understood in the literature. Therefore, we analyzed these issues in patients with GI cancer.
Demographics, clinical variables, and patient outcomes were abstracted from the medical record. Illness understanding and future expectations were retrieved from palliative care notes. We described additional treatment and outcomes after dPEG and estimated overall survival (OS).
From January 2015 to June 2017, 125 admitted patients with metastatic GI cancer underwent dPEG for MBO. Cancers were most commonly colorectal (34%) and pancreatic/ampullary (25%). During the dPEG admission, 32% (40 of 125) of patients had a palliative care consultation, and 22% (28 of 125) were asked about illness understanding and future expectations. All (28 of 28) reported good understanding of the advanced nature of their disease, but few were accurate about prognosis given their stage IV disease (10 of 28). Of the 117 (94%) discharged, 13% (15 of 117) received additional chemotherapy, which rarely prevented progression; half (63 of 117) had a do-not-resuscitate order; and most (101 of 117) were enrolled in hospice at death. Median time to death was 37 days (95% CI, 29 to 45 days); 6-month OS was 3.7% (95% CI, 1.2% to 8.4%).
dPEGs are placed close to end of life in patients with advanced GI cancer. A minority of patients receive additional chemotherapy post-dPEG. Many have adequate disease understanding, but chemotherapy benefit is low, and future expectations vary. This may be an opportunity for improved communication regarding palliative procedures in advanced cancer.
Quantum programming techniques and software have advanced significantly over the past five years, with a majority focusing on high-level language frameworks targeting remote REST library APIs. As ...quantum computing architectures advance and become more widely available, lower-level, system software infrastructures will be needed to enable tighter, co-processor programming and access models. Here we present XACC, a system-level software infrastructure for quantum-classical computing that promotes a service-oriented architecture to expose interfaces for core quantum programming, compilation, and execution tasks. We detail XACC's interfaces, their interactions, and its implementation as a hardware-agnostic framework for both near-term and future quantum-classical architectures. We provide concrete examples demonstrating the utility of this framework with paradigmatic tasks. Our approach lays the foundation for the development of compilers, associated runtimes, and low-level system tools tightly integrating quantum and classical workflows.
Quantum computing is an emerging computational paradigm that leverages the laws of quantum mechanics to perform elementary logic operations. Existing programming models for quantum computing were ...designed with fault-tolerant hardware in mind, envisioning standalone applications. However, near-term quantum computers are susceptible to noise which limits their standalone utility. To better leverage limited computational strengths of noisy quantum devices, hybrid algorithms have been suggested whereby quantum computers are used in tandem with their classical counterparts in a heterogeneous fashion. This {\it modus operandi} calls out for a programming model and a high-level programming language that natively and seamlessly supports heterogeneous quantum-classical hardware architectures in a single-source-code paradigm. Motivated by the lack of such a model, we introduce a language extension specification, called QCOR, that enables single-source quantum-classical programming. Programs written using the QCOR library and directives based language extensions can be compiled to produce functional hybrid binary executables. After defining the QCOR's programming model, memory model, and execution model, we discuss how QCOR enables variational, iterative, and feed forward quantum computing. QCOR approaches quantum-classical computation in a hardware-agnostic heterogeneous fashion and strives to build on best practices of high performance computing (HPC). The high level of abstraction in the developed language is intended to accelerate the adoption of quantum computing by researchers familiar with classical HPC.
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