65 research outputs found
GPU Based Acceleration of SystemC and Transaction Level Models for MPSOC Simulation
No full textWith increasing number of cores on a chip, the complexity of modeling hardware using virtual prototype is increasing rapidly. Typical SOCs today have multipro-cessors connected through a bus or NOC architecture which can be modeled using SystemC framework. SystemC is a popular language used for early design exploration and performance analysis of complex embedded systems. TLM2.0, an extension of SystemC, is increasingly used in MPSOC designs for simulating loosely and approxi-mately timed transaction level models. The OSCI reference kernel which implements SystemC library runs on a single thread, slowing up the simulation speed to a large extent. Previous works have used the computational power of multi-core systems and GPUs which can run multiple threads simultaneously, speeding up the simu-lation. Multi-core simulations are not as e���ective in cases where thread runtime is low, because synchronization overhead becomes comparable to thread runtime. Modern GPUs can run thousands of threads at a time and have shown good results for synthesizable designs in recent e���orts. However, development in these works are limited to synthesizable subsets of SystemC models, not supporting timed events for process communication. In this research work, a methodology is proposed for accelerating timed event based SystemC TLM2.0 model to GPU based kernel, which maps SystemC processes to CUDA threads in GPU, providing high data level par-allelism. This work aims to provide a scalable solution for simulating large MPSOC designs, facilitating early design exploration and performance analysis. Experiments have shown that the proposed technique provides a speed-up of the order of 100x for typical MPSOC designs
Quantifying spatial geotechnical uncertainty to advance the practice of risk assessment and decision-making in tunnel projects
No full textIncludes bibliographical references.2021 Fall.The largest element of technical and financial risk on any tunnel project lies in the ground conditions. The conventional practice of developing deterministic interpretations of ground conditions does not account for ground spatial variability nor quantify uncertainty. Given the large number of claims and litigations in the tunneling industry, it is evident that conventional practice is ineffective in assessing ground spatial variability and uncertainty.
Geostatistics-based methodologies are developed in this thesis to provide advantages over the qualitative and subjective deterministic interpretation of ground conditions with the probabilistic assessment of ground conditions as outputs. Geotechnical site investigation data from varied geological settings are utilized to offer effective solutions for unique challenges in tunnel projects and improve ground awareness.
As the first contribution of the thesis, a probabilistic geostatistical methodology is developed to quantify the soil transition location uncertainty in the longitudinal and transverse directions of tunneling. Results from application to a soil tunnel project reveal that soil transition locations identified from the methodology agree reasonably well with the ground truth transitions, estimated via the difference in the rates of chamber pressure dissipation at the tunnel springline. For a different soil tunnel project, the results from the methodology were found to be within three to eight rings of the soil transition location identified by a data-driven model developed to characterize as-encountered ground conditions.
Next, a geostatistics-based methodology is developed to generate quantitative estimates of karstic features' size, number, occurrence probability, and occurrence location within the tunnel envelope. Applying the methodology to a mixed-ground tunnel project in Malaysia reveals a presence of 2% to 6% average volumetric karstic void fraction for every 50 m of tunnel excavation. The results are utilized to estimate an average cumulative grout volume of 4000 m3 for the complete tunnel section.
Next, a risk-based methodology is developed to optimize geotechnical site investigations considering tunnel risks and geotechnical uncertainty. For the risk created by uncertainty in tool wear rate, geospatial assessments of geotechnical parameter uncertainty, tunnel risk consequences, and investigation accessibility are developed to identify priority locations for additional investigations on a soil tunnel project. The results revealed that additional investigations reduced geotechnical parameter uncertainty by about 40 % that led to a reduction in the location uncertainty of the first two cutterhead interventions by about 90 rings (~160 m).
Lastly, a methodology is developed to quantify the geostatistical model accuracy in predicting soil conditions, emphasizing predicting soil transitions. The methodology was applied to two soil tunnel projects to investigate the effect of geotechnical SI density and geological environment on geostatistical model accuracy. The results revealed that for a 100 m borehole spacing, geostatistical model accuracy in capturing soil transitions in a sedimentary and sequenced stratigraphy is about 60 %, while that for the heterogeneous glacial environment is less than 50 %.
The geostatistics-based methodologies presented in this thesis are developed with a vision to assist the tunneling community in (a) analyzing ground spatial variability and uncertainty and (b) tying the results from geostatistical modeling to tunnel risk assessment. The latter is expected to help the tunneling community realize the advantages of geostatistical modeling-based methodologies in improving tunnel construction performance
Min Metall Explor
No full textA ventilation research study was conducted by the National Institute for Occupational Safety and Health and a cooperating trona mine in the Green River basin of Wyoming, USA. The mine operation uses the longwall mining method in trona bed 17, a commonly mined unit in the region. The longwall face length is 228 m (750 ft), and caving on the face occurred up to the back of the longwall shields. The mine is ventilated using a main blowing fan and a bleeder shaft. For this study, sulfur hexafluoride (SF|) tracer gas was released in two separate monitoring experiments. For the first experiment, tracer gas was released on the face, this test focused on airflow along the longwall face of the active panel. Face test showed the airflow patterns to be more complex than just head-to-tail flow in the main ventilation air stream on the active panel. For the second experiment, tracer gas was released 2 crosscuts inby the face on the headgate side, this test focused on gas transport in the mined-out portion of the same active panel. Gob test showed a pathway of movement through the front of the active panel gob that moved outby from the tailgate corner. The primary pathway of tracer gas movement in the active panel gob was towards the headgate and tailgate bleeders and out of a bleeder shaft. The rate of movement towards the back of the gob was measured to be 0.19 m/s (37 fpm).CC999999/ImCDC/Intramural CDC HHSUnited States
Strategies for safe multi-armed bandits with logarithmic regret and risk
No full textAgmt dtd 12/16/2022 - LongShortWay, Inc; W911NF2110246 - Department of Defense/ARO; CCF-2007350 - National Science Foundationhttps://proceedings.mlr.press/v162/chen22e/chen22e.pdfFirst author draf
Cationic polypeptides contribute to the anti-HIV-1 activity of human seminal plasma
No full textMucosal surfaces of the reproductive tract as well as their secretions have important roles in preventing sexual transmission of HIV-1. In the current study, the majority of the intrinsic anti-HIV-1 activity of human seminal plasma (SP) was determined to reside in the cationic polypeptide fraction. Antiviral assays utilizing luciferase reporter cells and lymphocytic cells revealed the ability of whole SP to prevent HIV-1 infection, even when SP was diluted 3200-fold. Subsequent fractionation by continuous flow acid-urea (AU)- PAGE and antiviral testing revealed that cationic polypeptides within SP were responsible for the majority of anti-HIV-1 activity. A proteomic approach was utilized to resolve and identify 52 individual cationic polypeptides that contribute to the aggregate anti-HIV-1 activity of SP. One peptide fragment of semenogelin I, termed SG-1, was purified from SP by a multistep chromatographic approach, protein sequenced, and determined to exhibit anti-HIV-1 activity against HIV-1. Anti- HIV-1 activity was transient, as whole SP incubated for prolonged time intervals exhibited a proportional decrease in anti-HIV-1 activity that was directly attributed to the degradation of semenogelin I peptides. Collectively, these results indicate that the cationic polypeptide fraction of SP is active against HIV-1, and that semenogelin- derived peptides contribute to the intrinsic anti- HIV-1 activity of SP.—Martellini, J. A., Cole, A. C., Venkataraman, N., Quinn, G. A., Svoboda, P., Gangrade, B. K., Pohl, J., Sørensen, O. E., Cole, A. M. Cationic polypeptides contribute to the anti-HIV-1 activity of human seminal plasma
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