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51.
Simulation research on monomer agglomeration of nonmetallic inclusions in steel with a diffusion limited aggregation model 总被引:1,自引:0,他引:1
Hong Li Linxin Ning Juan Wen Jiongming Zhang Yasushi Sasaki Mitsutaka Hino 《北京科技大学学报(英文版)》2006,13(2):117-120
The monomer agglomeration of nonmetallic inclusions was simulated with a diffusion limited aggregation (DLA) model of the fractal theory. The simulation study with a random two-dimensional diffusion was carried out. The results indicate that the DLA model can be used for the simulation of agglomeration behavior of the cluster-type inclusions. The morphology of clusters was observed with SEM and compared with the simulated agglomerates. The modelling procedure of the DLA model is applicable for the agglomeration process. The uncertainty of agglomeration process and the persuasive average agglomerative ratio was analyzed. The factors about the agglomerative ratio with the collision path distance and the size of particles or seed were discussed. The adherence of the nonmetallic inclusions on the dam, the weir and the walls of a tundish, and the absorption of inclusions by stopper or nozzle were also discussed. 相似文献
52.
Yasushi Yagi Wataru Nishi Nels Benson Masahiko Yachida 《Machine Vision and Applications》2003,14(2):112-120
Described here is a method for estimating rolling and swaying motions of a mobile robot using optical flow. We have proposed
an image sensor with a hyperboloidal mirror for the vision-based navigation of a mobile robot. Its name is HyperOmni Vision.
The radial component of optical flow in HyperOmni Vision has a periodic characteristic. The circumferential component of optical
flow has a symmetric characteristic. The proposed method makes use of these characteristic to estimate robustly the rolling
and swaying motion of the mobile robot.
Correspondence to: Y. Yagi e-mail: y-yagi@sys.es.osaka-u.ac.jp 相似文献
53.
In this paper, an optimum-efficiency control scheme of synchronous reluctance motors is presented. There exists a variety of combinations of d- and q-axis current which provides a specific motor torque. The objective of the optimum-efficiency controller is to seek a combination of d- and q-axis current components, which provides minimum input power, that is, minimum losses at a certain operating point in steady state. A small amount of perturbation is added to the d-axis current reference for the purpose of searching a minimum input power operating point 相似文献
54.
55.
K Maekawa H Ohnishi T Hirase T Yamada T Matsuo 《Canadian Metallurgical Quarterly》1994,235(5):489-492
A 33-year-old pregnant woman suffered from acute anteroseptal myocardial infarction at the 19th gestational week. Despite periodic attacks of myocardial ischaemia after admission, the coronary arteriograms under the use of nitroglycerin were normal. Thereafter, she remained free from the ischaemic events with diltiazem hydrochloride and delivered a healthy baby. The coronary arteriography at puerperium also showed no organic narrowing. However, the provocative test with acetylcholine chloride caused severe spasm of the left anterior descending coronary artery. These findings strongly suggest that acute myocardial infarction in this pregnant woman was caused by coronary artery spasm. 相似文献
56.
Hidemi Yamachi Yasuhiro Tsujimura Yasushi Kambayashi Hisashi Yamamoto 《Reliability Engineering & System Safety》2006,91(9):1083-1094
N-version programming (NVP) is a programming approach for constructing fault tolerant software systems. Generally, an optimization model utilized in NVP selects the optimal set of versions for each module to maximize the system reliability and to constrain the total cost to remain within a given budget. In such a model, while the number of versions included in the obtained solution is generally reduced, the budget restriction may be so rigid that it may fail to find the optimal solution. In order to ameliorate this problem, this paper proposes a novel bi-objective optimization model that maximizes the system reliability and minimizes the system total cost for designing N-version software systems. When solving multi-objective optimization problem, it is crucial to find Pareto solutions. It is, however, not easy to obtain them. In this paper, we propose a novel bi-objective optimization model that obtains many Pareto solutions efficiently.We formulate the optimal design problem of NVP as a bi-objective 0–1 nonlinear integer programming problem. In order to overcome this problem, we propose a Multi-objective genetic algorithm (MOGA), which is a powerful, though time-consuming, method to solve multi-objective optimization problems. When implementing genetic algorithm (GA), the use of an appropriate genetic representation scheme is one of the most important issues to obtain good performance. We employ random-key representation in our MOGA to find many Pareto solutions spaced as evenly as possible along the Pareto frontier. To pursue improve further performance, we introduce elitism, the Pareto-insertion and the Pareto-deletion operations based on distance between Pareto solutions in the selection process.The proposed MOGA obtains many Pareto solutions along the Pareto frontier evenly. The user of the MOGA can select the best compromise solution among the candidates by controlling the balance between the system reliability and the total cost. 相似文献
57.
Shunpei Yamazaki Takuya Hirohashi Masahiro Takahashi Shunsuke Adachi Masashi Tsubuku Junichi Koezuka Kenichi Okazaki Yohsuke Kanzaki Hiroshi Matsukizono Seiji Kaneko Shigeyasu Mori Takuya Matsuo 《Journal of the Society for Information Display》2014,22(1):55-67
Our crystalline In–Ga–Zn oxide (IGZO) thin film has a c‐axis‐aligned crystal (CAAC) structure and maintains crystallinity even on an amorphous base layer. Although the crystal has c‐axis alignment, its a‐axis and b‐axis have random arrangement; moreover, a clear grain boundary is not observed. We fabricated a back‐channel‐etched thin‐film transistor (TFT) using the CAAC‐IGZO film. Using the CAAC‐IGZO film, more stable TFT characteristics, even with a short channel length, can be obtained, and the instability of the back channel, which is one of the biggest problems of IGZO TFTs, is solved. As a result, we improved the process of manufacturing back‐channel‐etched TFTs. 相似文献
58.
Yuika Suzuki Takuya Takeichi Kana Tanahashi Yoshinao Muro Yasushi Suga Tomoo Ogi Masashi Akiyama 《International journal of molecular sciences》2022,23(14)
Superficial epidermolytic ichthyosis (SEI) is an autosomal dominant inherited ichthyosis. SEI is caused by mutations in KRT2 and frequently shows erythroderma and widespread blistering at birth. We report the clinical manifestations of two patients from a Japanese family with SEI caused by a hotspot mutation, p.Glu487Lys, in KRT2. In addition, we summarize previous reports on SEI patients with the identical mutation. One of the two patients had disease onset at the age of 7 months. The other patient’s age of onset is unknown, but it was in childhood. Neither of the two patients showed erythroderma. To perform deep phenotyping, we studied the age of onset and the frequency of erythroderma in 34 reported SEI cases with the p.Glu487Lys mutation, including the present cases. Among the cases with sufficient clinical information, 44.4% of the cases that were due to p.Glu487Lys in KRT2 occurred at birth. Erythroderma was observed in 11.1% of the cases with p.Glu487Lys in KRT2. 相似文献
59.
The mass flow rate measurement using a critical nozzle shows the validity of the inviscid theory,indicating thatthe discharge coefficient increases and approaches unity as the Reynolds number increases under the ideal gas lawHowever,when the critical nozzle measures the mass flow rate of a real gas such as hydrogen at a pressure ofhundreds bar,the discharge coefficient exceeds unity,and the real gas effects should be taken into account.Thepresent study aims at investigating the flow features of the critical nozzle using high-pressured hydrogen gas.Theaxisymmetric,compressible Navier-Stokes computation is employed to simulate the critical nozzle flow,and afully implicit finite volume method is used to discretize the governing equation system.The real gas effects aresimulated to consider the intermolecular forces,which account for the possibility of liquefying hydrogen gas.Thecomputational results are compared with past experimental data.It has been found that the coefficient of dis-charge for real gas can be corrected properly below unity adopting the real gas assumption. 相似文献
60.
A multi-port D-R mutator with new current conveyors (CFCCIIs) as the four-port active element is proposed. Each CFCCII consists of a current follower added to a second-generation current conveyor (CCII). This proposed circuit is a simple configuration using CCIIs, CFCCIIs and grounded capacitances and is applied to higher order high-pass filters. This configuration can realize a superior transmission characteristic, inheriting the characteristic of the conventional LC filter. Since all the passive elements are grounded, the influence of parasitic elements of current conveyors can be reduced with this circuit configuration. As a result, this circuit is considered a suitable configuration for monolithic integration. Results obtained from the SPICE simulations show the realized filters have excellent performance and the circuit is effective. 相似文献