210 research outputs found

    Possibility/Necessity-Based Probabilistic Expectation Models for Linear Programming Problems with Discrete Fuzzy Random Variables

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    This paper considers linear programming problems (LPPs) where the objective functions involve discrete fuzzy random variables (fuzzy set-valued discrete random variables). New decision making models, which are useful in fuzzy stochastic environments, are proposed based on both possibility theory and probability theory. In multi-objective cases, Pareto optimal solutions of the proposed models are newly defined. Computational algorithms for obtaining the Pareto optimal solutions of the proposed models are provided. It is shown that problems involving discrete fuzzy random variables can be transformed into deterministic nonlinear mathematical programming problems which can be solved through a conventional mathematical programming solver under practically reasonable assumptions. A numerical example of agriculture production problems is given to demonstrate the applicability of the proposed models to real-world problems in fuzzy stochastic environments

    Fuzzy Random Weighted Weber Problems in Facility Location

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    This article considers facility location in a Weber problem with weights including both uncertainty and vagueness. By representing its weights as fuzzy random variables, it can be extended to a fuzzy random weighted Weber problem, and then formulated as a fuzzy random programming problem. By introducing possibility and necessity measures and chance constraints, the extended problem is reformulated to new two types of Weber problems. Based upon characteristics of facility location, theorem for solving the reformulated problems are shown

    Virtual Reality approaches for evacuation simulation of various disasters

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    This paper presents a virtual reality (VR) system of evacuation in the cases of various disasters. We considered a combination of disasters under realistic scenarios. Disaster simulations by numerical models were imported into the VR system to express a realistic situation. Not only disaster experts but also designers and non-professionals are able to share realistic experiences for escape from the disasters. This system is useful for performance-based design, planning of escape, disaster prevention, evacuation drill etc. The VR system consists of Building Information Modelling, physical simulation models for disasters and human behaviour’s simulation

    Study on estimation of wind pressure under roof tiles

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    This paper discusses an analytical method for estimating wind pressures under roof tiles induced by the interaction between internal pressures and external pressures.First,internal pressures on roof models,whose internal volume and gaps have values equivalent to those of a real roof tile,were measured in wind tunnel tests.Next,the internal pressures were estimated analytically by applying a non‐steady Bernoulli equation to the flow through the gap.The validity of the analytical method was examined by comparison with results of the wind tunnel tests.Finally,internal pressures on a whole roof were deduced from simultaneous external pressures through a roof,obtained from a wind tunnel test for a low‐rise building with a gable roof,using the analytical method

    青色光は滑膜肉腫に対して活性酸素種によるミトコンドリア機能障害を起こし、アポトーシスとオートファジーを誘導する

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    Background: Synovial sarcoma (SS) has limited treatment options and there is an urgent need to develop a novel therapeutic strategy to treat SS. Blue light (BL) has been shown to inhibit the growth of several cancer cells. However, the efficacy of BL in soft tissue sarcomas such as SS has not been demonstrated, and the detailed mechanism underlying the antitumor activity of BL is not fully understood. In this study, we investigated the antitumor effect of BL on SS. Methods: Human SS cell lines were continuously irradiated with BL using light-emitting diodes (LEDs) in an incubator for in vitro analysis. The chicken chorioallantoic membrane (CAM) tumors and xenograft tumors in mice were subjected to daily BL irradiation with LEDs. Results: BL caused growth inhibition of SS cells and histological changes in CAM tumors. BL also suppressed the migration and invasion abilities of SS cells. The type of cell death in SS cells was revealed to be apoptosis. Furthermore, BL induced excessive production of reactive oxygen species (ROS) in mitochondria, resulting in oxidative stress and malfunctioned mitochondria. Reducing the production of ROS using N-acetylcysteine (NAC), a ROS scavenger, attenuated the inhibitory effect of BL on SS cells and mitochondrial dysfunction. In addition, BL induced autophagy, which was suppressed by the administration of NAC. The autophagy inhibitor of 3-methyladenine and small interfering RNA against the autophagy marker light chain 3B facilitated apoptotic cell death. Moreover, BL suppressed tumor growth in a mouse xenograft model. Conclusion: Taken together, our results revealed that BL induced apoptosis via the ROS-mitochondrial signaling pathway, and autophagy was activated in response to the production of ROS, which protected SS cells from apoptosis. Therefore, BL is a promising candidate for the development of an antitumor therapeutic strategy targeting SS

    Discovery of Extended X-Ray emission from the unidentified TeV source HESS J1614-518 using the Suzaku Satellite

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    We report the Suzaku results of HESS J1614-518, which is the brightest extended TeV gamma-ray source discovered in the Galactic plane survey conducted using the H.E.S.S. telescope. We discovered three X-ray objects in the field of view of the X-ray Imaging Spectrometer (XIS), which were designated as Suzaku J1614-5141 (src A), Suzaku J1614-5152 (src B), and Suzaku J1614-5148 (src C). Src A is an extended source located at the peak position of HESS J1614-518, and therefore it is a plausible counterpart to HESS J1614-518. The X-ray flux in the 2-10 keV band is 5e-13 erg/s/cm^2, which is an order of magnitude smaller than the TeV flux. The photon index is 1.7, which is smaller than the canonical value of synchrotron emissions from high-energy electrons found in some supernova remnants. These findings present a challenge to models in which the origin of the TeV emission is the inverse Compton scattering of the cosmic microwave background by accelerated electrons that emit X-rays via synchrotron emission. Src B is located at a relatively dim region in the TeV band image; however, its hydrogen column density is the same as that of src A. Therefore, src B may also be physically related to HESS J1614-518. Src C is a foreground late-type B star. We also discovered a soft extended X-ray emission near HESS J1614-518.Comment: Accepted for publication in PASJ vol. 60 Suzaku Special Issue

    A phantom study investigating the relationship between ground-glass opacity visibility and physical detectability index in low-dose chest computed tomography

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    In this study, the relationship between ground-glass opacity (GGO) visibility and physical detectability index in low-dose computed tomography (LDCT) for lung cancer screening was investigated. An anthropomorphic chest phantom that included synthetic GGOs with CT numbers of -630 Hounsfield units (HU; high attenuation GGO: HGGO) and -800 HU (low attenuation GGO: LGGO), and three phantoms for physical measurements were employed. The phantoms were scanned using 12 CT systems located in 11 screening centers in Japan. The slice thicknesses and CT dose indices (CTDIvol) varied over 1.0-5.0 mm and 0.85-3.30 mGy, respectively, and several reconstruction kernels were used. Physical detectability index values were calculated from measurements of resolution, noise, and slice thickness properties for all image sets. Five radiologists and one thoracic surgeon, blind to one another\u27s observations, evaluated GGO visibility using a five-point scoring system. The physical detectability index correlated reasonably well with the GGO visibility (R2 = 0.709, p vol. Consequently, the CTDIvol also correlated reasonably well with the GGO visibility (R2 = 0.701, p vol was nearly dominant in the GGO visibility for image sets with different reconstruction kernels and slice thicknesses, used in this study

    Curative two-stage resection for synchronous triple cancers of the esophagus, colon, and liver: Report of a case

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    AbstractIntroductionCases of synchronous triple cancers of the esophagus and other organs curatively resected are rare.Presentation of caseA 73-year-old man was admitted to our hospital with bloody feces. He was diagnosed with synchronous triple cancers of the esophagus, colon, and liver. We selected a two-stage operation to safely achieve curative resection for all three cancers. The first stage of the operation comprised a laparoscopy-assisted sigmoidectomy and partial liver resection via open surgery. The patient was discharged without complications. Thirty days later, he was readmitted and thoracoscopic esophagectomy was performed. Although pneumonia-induced pulmonary aspiration occurred as a postoperative complication, it was treated conservatively. The patient was discharged on postoperative day 24.DiscussionEsophagectomy is a highly invasive procedure; thus, simultaneous surgery for plural organs, including the esophagus, may induce life-threatening, severe complications. Two-stage surgery is useful in reducing surgical stress in high-risk patients. For synchronous multiple cancers, the planning of two-stage surgery should be considered for each cancer to maintain organ function and reduce the stress and difficulty of each stage.ConclusionWe successfully treated synchronous triple cancers, including esophageal cancer, by a two-stage operation
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