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It is expected that we will solve combinatorial optimization problems efficiently by using DNA computing. Since, however; DNA computing depends on the property and behavior of DNA. Therefore we must take into account this fad in d...
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It is expected that we will solve combinatorial optimization problems efficiently by using DNA computing. Since, however; DNA computing depends on the property and behavior of DNA. Therefore we must take into account this fad in designing codes for DNA Computing. We propose a new evaluation method of codes for DNA computing and present results obtained by using the evaluation method.
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This paper presents a review of research reported on simulated annealing (SA). Different cooling/annealing schedules are summarized. Variants of SA are delineated. Recent applications of SA in engineering are reviewed.
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In order to improve electrical characteristics of FinFETs, various annealing treatments for dopant activation were studied in this work. The treatments including rapid thermal annealing (RTA), microwave annealing, and RTAand-laser...
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In order to improve electrical characteristics of FinFETs, various annealing treatments for dopant activation were studied in this work. The treatments including rapid thermal annealing (RTA), microwave annealing, and RTAand-laser annealing with different powers were investigated. The on-current and carrier mobility of FinFET are significantly improved by a RTA-and-laser annealing with suitable power; meanwhile, the leakage current, interface characteristics and device reliability can be simultaneously maintained. The improvement can be attributed to the high thermal activation energy, less dopant diffusion, and enhanced quality of interfacial layer during the gate first processes. Therefore, a RTA-and-laser annealing with suitable power is promising for manufacturing high performance FinFET. (C) 2017 Elsevier B.V. All rights reserved.
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Because of its special characteristics, hydrogen is welt-suited as a process atmosphere for many heat treatment processes in industrial furnaces. The powerful reduction effect is perfect, e.g. to bright anneal cold-rolled Cr/Cr-Ni...
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Because of its special characteristics, hydrogen is welt-suited as a process atmosphere for many heat treatment processes in industrial furnaces. The powerful reduction effect is perfect, e.g. to bright anneal cold-rolled Cr/Cr-Ni strip. Despite the highest convection necessary for maximum throughput, hydrogen's low specific weight has a positive influence on the energy consumption of the workbase fan in bell annealers or jet fans for heating and cooling in continuous annealing lines. The modern HICON/H/ bell annealer is the best alternative to traditional HNX technology in terms of utility consumption and emissions. Hydrogen can also crack residual rolling lubricant on the surface of the material thereby cleaning it in a process often used when annealing strip and wire coils in the bell annealer. Degreasing the strip surfaces generally becomes unnecessary, even with the highest quality material. EBNER exploits the characteristics of hydrogen in its HICON/H_2~R bell annealer facility as well as in continuous heat treatment lines while taking into account the danger of fire or explosion. The newest developments and experiences in the use of 100 percent hydrogen in bell annealers and continuous heat treatment facilities are detailed in the following.
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Ising machines are expected to solve combinatorial optimization problems efficiently by representing them as Ising models or equivalent quadratic unconstrained binary optimization (QUBO) models . However, upper bound exists on the...
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Ising machines are expected to solve combinatorial optimization problems efficiently by representing them as Ising models or equivalent quadratic unconstrained binary optimization (QUBO) models . However, upper bound exists on the computable problem size due to the hardware limitations of Ising machines. This paper propose a new hybrid annealing method based on partial QUBO extraction, called subQUBO model extraction, with multiple solution instances. For a given QUBO model, the proposed method obtains $N_I$ quasi-optimal solutions (quasi-ground-state solutions) in some way using a classical computer. The solutions giving these quasi-optimal solutions are called solution instances . We extract a size-limited subQUBO model as follows based on a strong theoretical background: we randomly select $N_S$ $(N_SN_I)$ solution instances among them and focus on a particular binary variable $x_i$ in the $N_S$ solution instances. If $x_i$ value is much varied over $N_S$ solution instances, it is included in the subQUBO model; otherwise, it is not. We find a (quasi-)ground-state solution of the extracted subQUBO model using an Ising machine and add it as a new solution instance. By repeating this process, we can finally obtain a (quasi-)ground-state solution of the original QUBO model. Experimental evaluations confirm that the proposed method can obtain better quasi-ground-state solution than existing methods for large-sized QUBO models.
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A detailed study of the oxidation behaviour of bare gamma-TiAl based alloy Ti-45Al-8Nb under various conditions, such as different atmospheres, pressures, temperatures (900 deg C, 1000 deg C) and times (100-200 h) is presented. Un...
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A detailed study of the oxidation behaviour of bare gamma-TiAl based alloy Ti-45Al-8Nb under various conditions, such as different atmospheres, pressures, temperatures (900 deg C, 1000 deg C) and times (100-200 h) is presented. Under high vacuum conditions (10~(-6) mbar) a continuous zone of alpha_2-Ti_3Al was formed at the surface with an oxygen-enriched phase on top. No oxide scale formation was obvious. During thermal treatment under Ar-atmosphere at low vacuum pressure (approximately 50mbar) mainly nitrides (TiN, Ti_2AlN) and Al_2O_3 particles were formed at the surface with an alpha_2-layer below. Annealing gamma-TiAl in hydrogen atmosphere (about 1040 mbar) led to the formation of a thick reaction zone. A TiO_2 layer was formed on top, followed by a mixed oxide scale. Beneath that scale a thick region with alumina, sigma-Nb_2Al and alpha_2-Ti_3Al was observed. Moreover, the oxidation behaviour of several thermally pre-treated samples was tested by cyclic oxidation at 900 deg C in air. The microstructure of the oxide scale formed after testing can be compared with that of non pre-treated material. gamma-TiAl annealed under high vacuum conditions exhibits the lowest oxidation rate, while the mass gain of specimens pre-treated under Ar-atmosphere increased rapidly in the first cycles. All pre-treated specimens exceeded a lifetime of 600 cycles at minimum. The reference material failed after 520 cycles.
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A detailed study of the oxidation behaviour of bare gamma-TiAl based alloy Ti-45Al-8Nb under various conditions, such as different atmospheres, pressures, temperatures (900 deg C, 1000 deg C) and times (100-200 h) is presented. Un...
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A detailed study of the oxidation behaviour of bare gamma-TiAl based alloy Ti-45Al-8Nb under various conditions, such as different atmospheres, pressures, temperatures (900 deg C, 1000 deg C) and times (100-200 h) is presented. Under high vacuum conditions (10~(-6) mbar) a continuous zone of alpha_2-Ti_3Al was formed at the surface with an oxygen-enriched phase on top. No oxide scale formation was obvious. During thermal treatment under Ar-atmosphere at low vacuum pressure (approximately 50mbar) mainly nitrides (TiN, Ti_2AlN) and Al_2O_3 particles were formed at the surface with an alpha_2-layer below. Annealing gamma-TiAl in hydrogen atmosphere (about 1040 mbar) led to the formation of a thick reaction zone. A TiO_2 layer was formed on top, followed by a mixed oxide scale. Beneath that scale a thick region with alumina, sigma-Nb_2Al and alpha_2-Ti_3Al was observed. Moreover, the oxidation behaviour of several thermally pre-treated samples was tested by cyclic oxidation at 900 deg C in air. The microstructure of the oxide scale formed after testing can be compared with that of non pre-treated material. gamma-TiAl annealed under high vacuum conditions exhibits the lowest oxidation rate, while the mass gain of specimens pre-treated under Ar-atmosphere increased rapidly in the first cycles. All pre-treated specimens exceeded a lifetime of 600 cycles at minimum. The reference material failed after 520 cycles.
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A full annealing cycle and two types of spheroidizing annealing cycle were implemented to improve poor forgeability for alloy-steel SNCM220 which is used for mechanical structures. Initial micro-structure was normalized ferrite+pe...
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A full annealing cycle and two types of spheroidizing annealing cycle were implemented to improve poor forgeability for alloy-steel SNCM220 which is used for mechanical structures. Initial micro-structure was normalized ferrite+pearlite and all the heat treatment was carried out with tube furnace filled with Ar gas to prevent oxidization. Critical temperature was investigated through a thermodynamics calculation of Thermo-calc soft. Among three types of heat treatment cycles, spheroidized structure was observed from the alloy-steel sample treated with intercritical annealing with the largest elongation rate while evaluating mechanical properties. Also, the effect of intercritical annealing holding time on the alloy-steel was investigated The results showed that as holding time was increased, carbide was more decomposed Further, hardness test results showed that hardness value did not change significantly between 5-10 hours of intercritical annealing cycle. When intercritical annealing cycle was repeated to investigate the effect of repeated frequency heat treatment cycle, the best micro-structure and mechanical property were achieved by repeating the intercritical annealing cycles three times.
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Quantum(-inspired) annealers show promise in solving combinatorial optimisation problems in practice. There has been extensive researches demonstrating the utility of D-Wave quantum annealer and quantum-inspired annealer, i.e., Fu...
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Quantum(-inspired) annealers show promise in solving combinatorial optimisation problems in practice. There has been extensive researches demonstrating the utility of D-Wave quantum annealer and quantum-inspired annealer, i.e., Fujitsu Digital Annealer on various applications, but few works are comparing these platforms. In this paper, we benchmark quantum(-inspired) annealers with three combinatorial optimisation problems ranging from generic scientific problems to complex problems in practical use. In the case where the problem size goes beyond the capacity of a quantum(-inspired) computer, we evaluate them in the context of decomposition. Experiments suggest that both annealers are effective on problems with small size and simple settings, but lose their utility when facing problems in practical size and settings. Decomposition methods extend the scalability of annealers, but they are still far away from practical use. Based on the experiments and comparison, we discuss the advantages and limitations of quantum(-inspired) annealers, as well as the research directions that may improve the utility and scalability of the these emerging computing technologies.
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Both directional and isothermal annealing experiments have been performed on the hot-rolled ODS nickel-based superalloy MA 754. Directional annealing of MA 754 produced an elongated, coarse grain structure with a {110} < 100 > texture fo...
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Both directional and isothermal annealing experiments have been performed on the hot-rolled ODS nickel-based superalloy MA 754. Directional annealing of MA 754 produced an elongated, coarse grain structure with a {110} < 100 > texture for all hot-zone velocities examined, with the grain aspect ratio and twin boundary density decreasing with increasing hot-zone velocity. Isothermal annealing also produced elongated structures, but with larger grain aspect ratios and a stronger {11 0}< 100 > texture. In order to elucidate the results of the experimental studies, a front-tracking computer-based model [H.J. Frost, C.V. Thompson, C.L. Howe, J.H. Whang, Scripta Metall. 22 (1988) 65-70] was modified to simulate the directional/isothermal annealing processes for materials with particles. Simulations of directional annealing with particles aligned in the direction of hot-zone movement could produce (at the appropriate hot-zone velocities) columnar grain structures with some finer grains clustered around the particles. Contrary to experimental observations, simulations of isothermal annealing in similar particle-containing material did not produce columnar grain structures, but equi-axed grains whose size was defined by the spacing between the lines of particles. Thus, the simulation results suggest that it is the texture, and not the particles, of the hot-rolled MA 754 that leads to a columnar grain structure.
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