Hierarchical Bayesian Inversion for Quantification of Mixed Aleatory and Epistemic Uncertainties in Model Parameters

The 20th working conference of the IFIP Working Group 7.5 on Reliability and Optimization of Structural Systems (IFIP 2022) will be held at Kyoto University, Kyoto, Japan, September 19-20, 2022.Uncertainties in the model parameters need to be properly characterized for the reliable and economic performance assesment of structures using a numerical model. Since not all parameters are trivial to measure directly, inverse uncertainty quantification (UQ) techniques, which infer the non-determinism in the model parameters by the measurments of the structural responses, are often necessary. Among such techniques, the class of Bayesian methods has been widely accepted as a coherent probabilistic approach to handle uncertainties in the inverse UQ. However, the main drawback of the conventional Bayesian methods is that they cannot quantify the inherent variability in the model parameters which causes the random failure of the structure. To fill this gap, the hierarchical Bayesian methods have gained increasing attention, in which a proability distribution is assigned to the model parameters to characterize their variability while its hyperparameters are treated as epistemic uncertainty and updated through Bayesian scheme. The first author and his co-workers have recently developed the hierarchical Bayesian approach using the staircase density function (SDF). This approach can consider the lack-of-knowledge on the distribution formats as epistemic uncertainty and infer the true-but-unknown distribution by updating the hyperparameters of SDF. This paper amis to illustrate its fundamental ideas and demonstrate its applicability to the estimation of a broad range of distributions through simple numerical test examples

Role of Inorganic and Organic Fractions in Animal Manure Compost in Lead Immobilization and Microbial Activity in Soil

This study aimed to identify how the ratio of inorganic-to-organic components in animal manure compost (AMC) affected both lead immobilization and microbial activity in lead-contaminated soil. When AMC containing 50% or more inorganic fraction with high phosphorous content was applied to contaminated soil, the amounts of water-soluble lead in it were suppressed by over 88% from the values in the soil without compost. The residual fraction under sequential extraction increased with the inorganic fraction in the AMC; however, in those AMCs, the levels of microbial enzyme activity were the same or less than those in the control soil. The application of AMC containing 25% inorganic fraction could alter the lead phases to be more insoluble while improving microbial enzyme activities; however, no suppression of the level of water-soluble lead existed during the first 30 days. These results indicate that compost containing an inorganic component of 50% or more with high phosphorus content is suitable for immobilizing lead; however, in the case where low precipitation is expected for a month, AMC containing 25% inorganic component could be used to both immobilize lead and restore microbial activity

Concurrent measurement of sample and reference waveforms in an optical-pump terahertz-probe system using a controlled optical diaphragm shutter

We present concurrent measurement of sample and reference terahertz waveforms for an optical-pump terahertz-probe spectrometer, using a controlled optical diaphragm shutter for the optical pump line. When waveforms are taken consecutively, laser power fluctuations and other experimental conditions can introduce spectral artefacts, thus a concurrent measurement is preferred. Instead of techniques based on double modulation, the use of the diaphragm shutter eliminates the need for a second lock-in amplifier and/or constricted alignment due to the use of a single chopper blade for modulating two signals, simultaneously. Drude fitting of the complex conductivity obtained for GaAs confirms that measurements obtained using our set-up agree with reported scattering times

Group Mobility Detection and User Connectivity Models for Evaluation of Mobile Network Functions

Group mobility in mobile networks is responsible for dynamic changes in user accesses to base stations, which eventually lead to degradation of network quality of service (QoS). In particular, the rapid movement of a dense group of users intensively accessing the network, such as passengers on a train passing through a densely populated area, significantly affects the perceived network QoS. For better design and operation of mobile network facilities and functions in response to this issue, monitoring group mobility and modeling the access patterns in group mobility scenarios are essential. In this paper, we focus on fast and dense group mobility and mobile network signaling data (control-plane data), which contains information related to mobility and connectivity. Firstly, we develop a lightweight method of group mobility detection to extract train passengers from all users\u27 signaling data without relying on precise location information about users, e.g., based on GPS. Secondly, based on the same signaling data and the results obtained by the detection method, we build connected/idle duration models for train users and non-train users. Finally, we leverage these models in mobile network simulations to assess the effectiveness of a dynamic base station switching/orientation scheme to mitigate QoS degradation with low power consumption in a group mobility scenario. The obtained models reveal that train users consume 3.5 times more resources than non-train users, which proves that group mobility has a significant effect on mobile networks. The simulation results show that the dynamic scheme of base station improves users\u27 perceived throughput, latency and jitter with small amount of additional power consumption in case of a moderate number of train users, but its ineffectiveness with larger number of train users is also shown. This would suggest that group mobility detection and the obtained connection/idle duration models based solely on control-plane data analytics are usable and useful for the development of mobility-aware functions in base stations

An energy‐frequency parameter for earthquake ground motion intensity measure

A novel scalar ground motion intensity measure (IM), termed the energy-frequency parameter, is proposed based on the Hilbert-Huang transform. To validate the effectiveness of the proposed IM, the correlation analysis between the engineering demand parameter (EDP) and energy-frequency parameter is performed using 1992 recorded ground motions, in which EDP is the maximum inter-storey drift of structures obtained by nonlinear time-history analysis. Results show that the energy-frequency parameter has a strong linear correlation with EDP at natural logarithm, and this correlation is applicable for various structural fundamental periods. We also verified that the lognormal cumulative distribution function can characterize the energy-frequency parameter-based fragility function, which can further facilitate the application of the parameter in seismic risk analysis. Besides, the strong correlation between the energy-frequency parameter and other IMs (such as PGA, PGV, PGD, CAV, (Formula presented.), (Formula presented.), and SI) potentially makes the proposed IM widely applicable in seismic risk analysis. Moreover, since the energy-frequency parameter depends only on the frequency-domain characteristics of the ground-motion signal, it may closely link to seismological theory and provide new insights into seismology engineering

Diacylglycerol kinase ζ inhibits myocardial atrophy and restores cardiac dysfunction in streptozotocin-induced diabetes mellitus

<p>Abstract</p> <p>Background</p> <p>Activation of the diacylglycerol (DAG)-protein kinase C (PKC) pathway has been implicated in the pathogenesis of a number of diabetic complications. Diacylglycerol kinase (DGK) converts DAG to phosphatidic acid and acts as an endogenous regulator of PKC activity. Akt/PKB is associated with a downstream insulin signaling, and PKCβ attenuates insulin-stimulated Akt phosphorylation.</p> <p>Methods and Results</p> <p>We examined transgenic mice with cardiac-specific overexpression of DGKζ (DGKζ-TG) compared to wild type (WT) mice in streptozotocin-induced (STZ, 150 mg/kg) diabetic and nondiabetic conditions. After 8 weeks, decreases in heart weight and heart weight/body weight ratio in diabetic WT mice were inhibited in DGKζ-TG mice. Echocardiography at 8 weeks after STZ-injection demonstrated that decreases in left ventricular end-diastolic diameter and fractional shortening observed in WT mice were attenuated in DGKζ-TG mice. Thinning of the interventricular septum and the posterior wall in diabetic WT hearts were blocked in DGKζ-TG mice. Reduction of transverse diameter of cardiomyocytes isolated from the left ventricle in diabetic WT mice was attenuated in DGKζ-TG mice. Cardiac fibrosis was much less in diabetic DGKζ-TG than in diabetic WT mice. Western blots showed translocation of PKCβ and δ isoforms to membrane fraction and decreased Akt/PKB phosphorylation in diabetic WT mouse hearts. However in diabetic DGKζ-TG mice, neither translocation of PKC nor changes Akt/PKB phosphorylation was observed.</p> <p>Conclusion</p> <p>DGKζ modulates intracellular signaling and improves the course of diabetic cardiomyopathy. These data may suggest that DGKζ is a new therapeutic target to prevent or reverse diabetic cardiomyopathy.</p

Noninvasive monitoring of deterioration in skeletal muscle function with forearm cast immobilization and the prevention of deterioration

BACKGROUND: In this research inactivity was simulated by immobilizing the forearm region in a plaster cast. Changes in skeletal muscle oxidative function were measured using near-infrared spectroscopy (NIRS), and the preventative effect of the training protocol on deterioration of skeletal muscle and the clinical utility of NIRS were examined. METHODS: Fourteen healthy adult men underwent immobilization of the forearm of the non-dominant arm by plaster cast for 21 days. Eight healthy adult subjects were designated as the immobilization group (IMM) and six were designated as the immobilization + training group (IMM+TRN). Grip strength, forearm circumference and dynamic handgrip exercise endurance were measured before and after the 21-day immobilization period. Using NIRS, changes in oxidative function of skeletal muscles were also evaluated. Muscle oxygen consumption recovery was recorded after the completion of 60 seconds of 40% maximum voluntary contraction (MVC) dynamic handgrip exercise 1 repetition per 4 seconds and the recovery time constant (TcVO(2)mus) was calculated. RESULTS: TcVO(2)mus for the IMM was 59.7 ± 5.5 seconds (average ± standard error) before immobilization and lengthened significantly to 70.4 ± 5.4 seconds after immobilization (p < 0.05). For the IMM+TRN, TcVO(2)mus was 78.3 ± 6.2 seconds before immobilization and training and shortened significantly to 63.1 ± 5.6 seconds after immobilization and training (p < 0.05). CONCLUSIONS: The training program used in this experiment was effective in preventing declines in muscle oxidative function and endurance due to immobilization. The experimental results suggest that non-invasive monitoring of skeletal muscle function by NIRS would be possible in a clinical setting

Myeloid-derived suppressor cells correlate with patient outcomes in hepatic arterial infusion chemotherapy for hepatocellular carcinoma

Hepatic arterial infusion chemotherapy (HAIC) has been employed as an alternative therapy to sorafenib for the patients with advanced hepatocellular carcinoma (HCC). In this study, we performed a comparative analysis of various immune cell responses including tumor-associated antigen (TAA)-specific T cells, regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) in advanced HCC patients treated with HAIC. Thirty-six HCC patients were examined in the study. Interferon gamma enzyme-linked immunospot assays were performed to examine the frequency of TAA-specific T cells. The frequencies of Tregs and MDSCs were examined by multicolor fluorescence-activated cell sorting analysis. The treatment with HAIC using interferon (IFN)/5-fluorouracil (FU) or IFN/FU + cisplatin modulated the frequencies of various immune cells. In 22.2 % of patients, the frequency of TAA-specific T cells increased after HAIC. Although the frequency of Tregs decreased after HAIC, it was not associated with the prognosis of patients. An analysis of prognostic factors for overall survival identified diameter of the tumor (<3.0 cm), absence of major portal vein invasion, absence of distant metastasis, Union Internationale Contre Le Cancer tumor lymph node metastasis stage (I or II), neutrophil lymphocytic ratio (<2.1) and the frequency of MDSCs (<30.5 %) as factors that prolonged overall survival time after HAIC. Even in the group adjusted with progressive levels of tumors, patients with a low frequency of MDSCs had a significantly longer overall survival time. In conclusion, the frequency of MDSCs before the treatment is a prognostic factor in HAIC against HCC. © 2016 Springer-Verlag Berlin Heidelber