Similarity-Based Parameter Transferability in the Quantum Approximate Optimization Algorithm

The quantum approximate optimization algorithm (QAOA) is one of the most promising candidates for achieving quantum advantage through quantum-enhanced combinatorial optimization. A near-optimal solution to the combinatorial optimization problem is achieved by preparing a quantum state through the optimization of quantum circuit parameters. Optimal QAOA parameter concentration effects for special MaxCut problem instances have been observed, but a rigorous study of the subject is still lacking. In this work we show clustering of optimal QAOA parameters around specific values; consequently, successful transferability of parameters between different QAOA instances can be explained and predicted based on local properties of the graphs, including the type of subgraphs (lightcones) from which graphs are composed as well as the overall degree of nodes in the graph (parity). We apply this approach to several instances of random graphs with a varying number of nodes as well as parity and show that one can use optimal donor graph QAOA parameters as near-optimal parameters for larger acceptor graphs with comparable approximation ratios. This work presents a pathway to identifying classes of combinatorial optimization instances for which variational quantum algorithms such as QAOA can be substantially accelerated.Comment: 22 pages, 21 figures, 3 tables, 1 algorithm. arXiv admin note: substantial text overlap with arXiv:2106.0753

Insulin-induced lipohypertrophy: clinical and ultrasound characteristics

Background: Lipohypertrophy is primary dermal complication of insulin therapy. The data on the prevalence of lipohypertrophy in diabetic subjects are inconsistent, that may be due to the lack of sensitivity and subjectivity of palpation as diagnostic technique. Meanwhile, the reliability of lipohypertrophy detection can be increased by ultrasound. Aims: to compare clinical and ultrasound characteristics and to determine the risk factors of insulin-induced lipohypertrophy in diabetic subjects. Materials and methods: We observed 82 patients, including 26 individuals with type 1 diabetes and 56 subjects with type 2 diabetes. Duration of insulin therapy varied from 3 months to 37 years (median 14 years). The sites of insulin injections were assessed by palpation and ultrasound. Visualization protocol included gray-scale densitometry, strain elastography, and 3D Doppler power ultrasound. Scaled evaluation of ultrasound sings was applied. Insulin injection technique was assessed by questionnaire. Serum levels of insulin antibodies were determined by ELISA. Results: Lipohypertrophy was revealed by palpation and ultrasound in 57 and 80 patients (70% and 98%) respectively. Total lipohypertrophy area, acoustic density and total ultrasound score showed weak positive correlations with daily insulin dose (r=0.3, r=0.3 and r=0.35, respectively, all p0.006). Patients receiving insulin analogues had smaller area of abdominal lipohypertrophy than those on human insulin (p=0.03). A positive correlation was found between abdominal lipohypertrophy area and mean postprandial glucose (r=0.35, p=0.001). A rare needle change and injections in lipohypertrophy sites were the most common deviations in insulin injection technique (70 and 47 subjects, 85% and 53% respectively). The levels of insulin antibodies showed no association with lipohypertrophy parameters. Conclusions: Patients with type 1 and type 2 diabetes demonstrate high prevalence of lipohypertrophy in insulin injection sites. Ultrasonography is more sensitive method of diagnostics of lipohypertrophy compared with palpation. Insulin-induced lipohypertrophy is associated with errors in injection technique and higher insulin doses

Plasma Technology for Producing Coverings on Building Materials

Results of plasma processing of construction materials are presented in the article. The article also covers the plasma generator construction and technology of receiving protectively decorative covering on concrete that were developed by the authors. This plasma generator construction and technology provide coverings on concrete with strength and production characteristics that are superior to the existing alternatives. Results of the calculation and experimental research of the surface layer are presented. The technological parameters that influence the characteristics of the covering are given

Influence of Powder Characteristics on Processability of AlSi12 Alloy Fabricated by Selective Laser Melting

Selective laser melting (SLM) is one of the additive manufacturing technologies that allows for the production of parts with complex shapes from either powder feedstock or from wires. Aluminum alloys have a great potential for use in SLM especially in automotive and aerospace fields. This paper studies the influence of starting powder characteristics on the processability of SLM fabricated AlSi12 alloy. Three different batches of gas atomized powders from different manufacturers were processed by SLM. The powders differ in particle size and its distribution, morphology and chemical composition. Cubic specimens (10 mm × 10 mm × 10 mm) were fabricated by SLM from the three different powder batches using optimized process parameters. The fabrication conditions were kept similar for the three powder batches. The influence of powder characteristics on porosity and microstructure of the obtained specimens were studied in detail. The SLM samples produced from the three different powder batches do not show any significant variations in their structural aspects. However, the microstructural aspects differ and the amount of porosity in these three specimens vary significantly. It shows that both the flowability of the powder and the apparent density have an influential role on the processability of AlSi12 SLM samples

Influence of Powder Characteristics on Processability of AlSi12 Alloy Fabricated by Selective Laser Melting

Selective laser melting (SLM) is one of the additive manufacturing technologies that allows for the production of parts with complex shapes from either powder feedstock or from wires. Aluminum alloys have a great potential for use in SLM especially in automotive and aerospace fields. This paper studies the influence of starting powder characteristics on the processability of SLM fabricated AlSi12 alloy. Three different batches of gas atomized powders from different manufacturers were processed by SLM. The powders differ in particle size and its distribution, morphology and chemical composition. Cubic specimens (10 mm × 10 mm × 10 mm) were fabricated by SLM from the three different powder batches using optimized process parameters. The fabrication conditions were kept similar for the three powder batches. The influence of powder characteristics on porosity and microstructure of the obtained specimens were studied in detail. The SLM samples produced from the three different powder batches do not show any significant variations in their structural aspects. However, the microstructural aspects differ and the amount of porosity in these three specimens vary significantly. It shows that both the flowability of the powder and the apparent density have an influential role on the processability of AlSi12 SLM samples

Similarity-based parameter transferability in the quantum approximate optimization algorithm

The quantum approximate optimization algorithm (QAOA) is one of the most promising candidates for achieving quantum advantage through quantum-enhanced combinatorial optimization. A near-optimal solution to the combinatorial optimization problem is achieved by preparing a quantum state through the optimization of quantum circuit parameters. Optimal QAOA parameter concentration effects for special MaxCut problem instances have been observed, but a rigorous study of the subject is still lacking. In this work we show clustering of optimal QAOA parameters around specific values; consequently, successful transferability of parameters between different QAOA instances can be explained and predicted based on local properties of the graphs, including the type of subgraphs (lightcones) from which graphs are composed as well as the overall degree of nodes in the graph (parity). We apply this approach to several instances of random graphs with a varying number of nodes as well as parity and show that one can use optimal donor graph QAOA parameters as near-optimal parameters for larger acceptor graphs with comparable approximation ratios. This work presents a pathway to identifying classes of combinatorial optimization instances for which variational quantum algorithms such as QAOA can be substantially accelerated

Measurements of the HDO/H2O Isotopic Ratio in the Asian Summer Monsoon

International audienceThe Asian Summer Monsoon (ASM) is one of the world's largest weather systems, and forms one of the main pathways by which water vapor enters the UTLS. Uplift in the region lofts highly polluted air from South Asia, making the region an important driver of both stratospheric chemistry and the stratospheric radiation budget. Uplifted air tends to be confined by the monsoon anticyclone, but may enter the stratosphere through uplift within the anticyclone, or via large scale shedding events along its edges. We report here on in situ measurements in the monsoon UTLS of water vapor and its isotopic composition (the ratio of HDO/H2O), an important tracer of uplift processes and of convective activity in general. Measurements were made by the Chicago Water Isotope Spectrometer (ChiWIS) in both the StratoClim (2017) and ACCLIP (2022) campaigns, at monsoon center and in monsoon outflow, respectively. We use these measurements to diagnose the importance of overshooting convection in water transport by the Asian monsoon, characterize the extent to which convection-driven water vapor perturbations propagate to higher altitudes and contribute to the overall stratospheric water budget, and explore cirrus properties in the ASM region