143 research outputs found

    Transfer Routing of Ore Yard by Decentralized Agent Method

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    In steel works, iron ores are stored in ore yard and sent to various plants of down stream accoding to transfer requests. To attain stable operation, it is neccesary to keep a certain allowable stock level in ore tanks of all plants. To this purpose, ore transfer routing method has been developed based on decentralized agent method. In case of disaster such as a big earthquake or a big fire, damages in the facilities of industrial complex may be unavoidable. In this paper, decentralized optimization method is tested to cope with such emergencies. Decentralized agents corresponding to kind of ore make their own transfer route plan exchanging information with others. As the application of the proposed method, transfer scheduling in ore yard in steel works are made in case of destruction of transfer facilities

    Transfer Planning of Molten Metals in Steel Worksby Decentralized Agent

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    In steel works, molten metals discharged from blast furnace are put into a pan for transportation called torpedo and transported to steel making factory by a locomotive. In molten metals transportation, it becomes issues to prevent temperature drop of molten metals for stable production of down stream plants to shorten transportation time. Therefore it is necessary to make an appropriate plan for molten metals transfer considering the production and the transportation simultaneously. In this paper, molten metals transfer planning method is proposed including production scheduling. That is, torpedo schedule, transfer request assignment and route plan of locomotives are optimized according to each objective

    A passively Q-switched compact Er:Lu2O3 ceramics laser at 2.8 μm with a graphene saturable absorber

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    We have demonstrated a passively Q-switched Er:Lu2O3 ceramics laser using a monolayer graphene saturable absorber (SA). Stable pulsed operation with watt-level average power was achieved by a compact linear cavity without focusing on the SA. This is the first demonstration of a passively Q-switched mid-IR Er:Lu2O3 laser using a graphene SA. A maximum pulse energy of 9.4 μJ and a peak power of 33 W were achieved with a 247 ns pulse duration. To our knowledge, this is the shortest pulse duration, highest pulse energy, and highest peak power obtained with a graphene SA in the 3 μm wavelength region

    Prognostic value of an increased in flourine-18 deoxyglucose uptake in patients with myocardial infarction: Comparision with stress thallium imaging

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    AbstractObjectives. This study was undertaken to evaluate the prognostic value of an increase in fluorine (F)-18 deoxyglucose uptake compared wilh clinical, angiographic and stress thallium findings in patients with myocardial infarction.Background. Positron emission tomography (PET) imaging using F-18 deoxyglucose has been applied to assess tissue viability in patients with coronary artery disease. We hypothesized that patients with a myocardial segment with augmented F-18 deoxyglucose uptake are at high risk for a future cardiac event.Methods. One hundred fifty-eight consecutive patients with myocardial infarction referred for F-18 deoxyglucose PET and stress thallium scans were studied. Follow-up was obtained in 84 patients at a mean interval of 23 months to investigate prognostic implications of radionuclide studies.Results. Seventeen patients had a cardiac event during the follow-up interval. Univariate analysis showed that an increase in F-18 deosyglucose uptake was the best predictor of a future cardiac event (p = 0.0006), followed by the number of stenosed vessels (p = 0.008). In the multivariate analysis, when an increase in F-18 deoxyglucose uptake was entered into the model, only angiographic variables had an independent value, whereas no other radionuclide variables showed value. Among patients who did not show redistribution, a future cardiac event was observed more often in patients with than in those without an increase in F-18 deoxyglucose uptake (p < 0.05).Conclusions. Thus, an increase in F-18 deoxyglucose uptake seemed to be the best predictor of a future cardiac event among all clinical, angiographic and redionuclide variables in this study of stable patients with myocardial infarction. Even when a stress thallium-201 scan does not show redistribution, those patients who have an increase in F-18 deoxyglucose uptake in a PET study may be at risk for a future cardiac event, and these patients may need aggressive treatment to prevent a future cardiac event

    Simple noise reduction for DWI

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    Our purpose in this study was to reduce the noise in order to improve the SNR of Dw images with high b-value by using two correction schemes. This study was performed with use of phantoms made from water and sucrose at different concentrations, which were 10, 30, and 50 weight percent (wt%). In noise reduction for Dw imaging of the phantoms, we compared two correction schemes that are based on the Rician distribution and the Gaussian distribution. The highest error values for each concentration with use of the Rician distribution scheme were 7.3 % for 10 wt%, 2.4 % for 30 wt%, and 0.1 % for 50 wt%. The highest error values for each concentration with use of the Gaussian distribution scheme were 20.3 % for 10 wt%, 11.6 % for 30 wt%, and 3.4 % for 50 wt%. In Dw imaging, the noise reduction makes it possible to apply the correction scheme of Rician distribution

    Histopathological evaluation of gastric mucosal environments in peptic ulcer using the endoscopic 5-point gastric biopsy method.

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    Although a strong association has been established between chronic Helicobacter pylori infection and peptic ulcers, the role of H. pylori is not necessarily causative because there are many patients infected with H. pylori who do not develop peptic ulcer. Therefore, we studied the relationship between the gastric mucosal environment and the development of peptic ulcers. We examined 165 endoscopic biopsy specimens from the gastric mucosa of 33 patients with peptic ulcers using the 5-point gastric biopsy method. The follow-up biopsies done within 3 weeks were well correlated with the first biopsy samples. We also reviewed the clinicohistopathological findings of 2250 endoscopic biopsy specimens from 450 patients with active gastric and/or duodenal ulcers. Over 90% of the patients with duodenal ulcer, with or without gastric ulcer, had no fundic gland atrophy, and a high incidence of intestinal metaplasia and pyloric mucosal atrophy was found in the patients with gastric ulcer. These findings suggest that patients with concomitant active gastric and duodenal ulcers exhibit severe atrophic changes in the antral mucosa but not in the fundic mucosa.</p
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