scholarly journals Study on the Time-lag Failure of Sandstone With Different Degrees of Unloading Damage

2019 ◽  
Author(s):  
Qiao Jiang ◽  
Jianlin Li ◽  
Zuosen Luo ◽  
Xiaoliang Xu ◽  
Eleyas Assefa ◽  
...  
Keyword(s):  
Large Scale ◽  
Time Lag ◽  
Prediction Method ◽  
Damage Threshold ◽  
Triaxial Tests ◽  
Underground Structures ◽  
Support Design ◽  
Sandstone Rock ◽  
Threshold Time ◽  
Unloading Time

The unloading effect of rock mass excavation is an inevitable practice, and it’s often characterized by a relatively large-scale engineering hazard with a noticeable time lag.A set of unloading triaxial tests were conducted on a sandstone rock to establish the deformation law and the threshold time. Based on the renormalization group theory, the unloading sandstone model was developed by considering the interaction between particles. Similarly, a logistic model was used to predict the unloading damage of sandstone. The unloading time lag damage of sandstone rock was predicted by using the damage threshold. The research shows that: (1) The higher the degree of unloading, the shorter the time-lag failure. (2) The damage range of critical values was optimized. (3) The error between the predicted value and the experimental value of the time threshold was almost less than 5 %, the prediction result was found to be good, and the employed logistic evolution model was reasonable. The findings of this research provide a prediction method and precise information about the mechanism of unloading time lag deformation. Therefore, it can be used as a reference for excavation-support design of underground structures.

Flow slide prediction method: influence of slope geometry

1998 ◽  
Vol 35 (1) ◽  
pp. 43-54 ◽  
Author(s):  
T P Stoutjesdijk ◽  
M B de Groot ◽  
J Lindenberg
Keyword(s):  
Large Scale ◽  
Prediction Method ◽  
Slope Instability ◽  
Initial Stresses ◽  
Triaxial Tests ◽  
Gradual Change ◽  
Loose Sand ◽  
Flow Slide ◽  
Flow Slides ◽  
Constitutive Properties

A quasi-two-dimensional method is presented for predicting liquefaction flow slides in a slope with saturated loose sand. The initial stresses at the start of the actual flow slide process are predicted assuming completely drained conditions during the gradual change in slope geometry caused by erosion or sedimentation. The condition for a flow slide is considered to be the presence of at least one sand element in a metastable stress state, i.e., a state in which the undrained response to any quick change in load, however small it may be, consists of a sudden large increase in pore pressure. The metastability of any sand element is predicted as a function of its constitutive properties, its location in the slope, and the slope geometry. The constitutive properties are derived from dry triaxial tests and basically describe the liquefiability (brittleness) of the sand. The metastability criterion for a soil element in a slope is different from that under triaxial loading. Flow slides observed in large-scale tests occurred at the conditions predicted with the model.Key words: loose sand, flow slides, liquefaction, collapse, slope instability.

THE WALTHAM SYSTEM AND EARLY AMERICAN TEXTILE COST ACCOUNTING 1813–1848

1980 ◽  
Vol 7 (1) ◽  
pp. 1-15 ◽  
Author(s):  
David M. Porter
Keyword(s):  
Large Scale ◽  
Time Lag ◽  
Cost Accounting ◽  
Industrial Enterprise ◽  
Early American

This study of the original accounting records of a pioneering American industrial enterprise narrows by one half the time lag between the earliest known English and American applications of industrial cost accounting. The research indicates that the precursors of the costing systems now considered essential tools of management were in use virtually from the beginning of large scale industry in America.

scholarly journals Interactive Exploration of Large-Scale UI Datasets with Design Maps

2021 ◽  
Author(s):  
Luis A Leiva ◽  
Asutosh Hota ◽  
Antti Oulasvirta
Keyword(s):  
User Interface ◽  
Point Cloud ◽  
Large Scale ◽  
Mobile Apps ◽  
Online Resources ◽  
Design Tools ◽  
Support Design ◽  
Design Exploration ◽  
Clustering Techniques ◽  
Cloud Points

Abstract Designers are increasingly using online resources for inspiration. How to best support design exploration without compromising creativity? We introduce and study Design Maps, a class of point-cloud visualizations that makes large user interface datasets explorable. Design Maps are computed using dimensionality reduction and clustering techniques, which we analyze thoroughly in this paper. We present concepts for integrating Design Maps into design tools, including interactive visualization, local neighborhood exploration and functionality to integrate existing solutions to the design at hand. These concepts were implemented in a wireframing tool for mobile apps, which was evaluated with actual designers performing realistic tasks. Overall, designers find Design Maps supporting their creativity (avg. CSI score of 74/100) and indicate that the maps producing consistent whitespacing within cloud points are the most informative ones.

scholarly journals Forecast of International Trade of Lithium Carbonate Products in Importing Countries and Small-Scale Exporting Countries

2021 ◽  
Vol 13 (3) ◽  
pp. 1251
Author(s):  
Yichi Zhang ◽  
Zhiliang Dong ◽  
Sen Liu ◽  
Peixiang Jiang ◽  
Cuizhi Zhang ◽  
...  
Keyword(s):  
International Trade ◽  
Large Scale ◽  
Prediction Method ◽  
Lithium Ion ◽  
Lithium Carbonate ◽  
Raw Material ◽  
Small Scale ◽  
Trade Restrictions ◽  
Energy Field ◽  
Structure Of Trade

As the raw material of lithium-ion batteries, lithium carbonate plays an important role in the development of new energy field. Due to the extremely uneven distribution of lithium resources in the world, the security of supply in countries with less say would be greatly threatened if trade restrictions or other accidents occurred in large-scale exporting countries. It is of great significance to help these countries find new partners based on the existing trade topology. This study uses the link prediction method, based on the perspective of the topological structure of trade networks in various countries and trade rules, and eliminates the influence of large-scale lithium carbonate exporting countries on the lithium carbonate trade of other countries, to find potential lithium carbonate trade links among importing and small-scale exporting countries, and summarizes three trade rules: (1) in potential relationships involving two net importers, a relationship involving either China or the Netherlands is more likely to occur; (2) for all potential relationships, a relationship that actually occurred for more than two years in the period in 2009–2018 is more likely to occur in the future; and (3) potential relationships pairing a net exporter with a net importer are more likely to occur than other country combinations. The results show that over the next five to six years, Denmark and Italy, Netherlands and South Africa, Turkey and USA are most likely to have a lithium carbonate trading relationship, while Slovenia and USA, and Belgium and Thailand are the least likely to trade lithium carbonate. Through this study, we can strengthen the supply security of lithium carbonate resources in international trade, and provide international trade policy recommendations for the governments of importing countries and small-scale exporting countries.

scholarly journals An information theoretic approach to link prediction in multiplex networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Hossein Jafari ◽  
Amir Mahdi Abdolhosseini-Qomi ◽  
Masoud Asadpour ◽  
Maseud Rahgozar ◽  
Naser Yazdani
Keyword(s):  
Real World ◽  
Link Prediction ◽  
Large Scale ◽  
Similarity Measures ◽  
Prediction Method ◽  
General Purpose ◽  
Fast Method ◽  
Theoretic Approach ◽  
Multiplex Networks ◽  
Wide Range

AbstractThe entities of real-world networks are connected via different types of connections (i.e., layers). The task of link prediction in multiplex networks is about finding missing connections based on both intra-layer and inter-layer correlations. Our observations confirm that in a wide range of real-world multiplex networks, from social to biological and technological, a positive correlation exists between connection probability in one layer and similarity in other layers. Accordingly, a similarity-based automatic general-purpose multiplex link prediction method—SimBins—is devised that quantifies the amount of connection uncertainty based on observed inter-layer correlations in a multiplex network. Moreover, SimBins enhances the prediction quality in the target layer by incorporating the effect of link overlap across layers. Applying SimBins to various datasets from diverse domains, our findings indicate that SimBins outperforms the compared methods (both baseline and state-of-the-art methods) in most instances when predicting links. Furthermore, it is discussed that SimBins imposes minor computational overhead to the base similarity measures making it a potentially fast method, suitable for large-scale multiplex networks.

Experimental study on particle breakage of carbonate gravels under cyclic loadings through Large-scale triaxial tests

2021 ◽  
pp. 100632
Author(s):  
Zhigang Cao ◽  
Jiaji Chen ◽  
Xingchi Ye ◽  
Chuan Gu ◽  
Zhen Guo ◽  
...  
Keyword(s):  
Experimental Study ◽  
Large Scale ◽  
Particle Breakage ◽  
Triaxial Tests

scholarly journals Influence of El Niño Wind Stress Anomalies on South Brazil Bight Ocean Volume Transports

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Luiz Paulo de Freitas Assad ◽  
Carina Stefoni Böck ◽  
Rogerio Neder Candella ◽  
Luiz Landau
Keyword(s):  
Stress Field ◽  
Interannual Variability ◽  
Wind Stress ◽  
Large Scale ◽  
Time Lag ◽  
Surface Wind ◽  
Circulation Model ◽  
Volume Transport ◽  
Wind Stress Field ◽  
Volume Transports

The knowledge of wind stress variability could represent an important contribution to understand the variability over upper layer ocean volume transports. The South Brazilian Bight (SBB) circulation had been studied by numerous researchers who predominantly attempted to estimate its meridional volume transport. The main objective and contribution of this study is to identify and quantify possible interannual variability in the ocean volume transport in the SBB induced by the sea surface wind stress field. A low resolution ocean global circulation model was implemented to investigate the volume transport variability. The results obtained indicate the occurrence of interannual variability in meridional ocean volume transports along three different zonal sections. These results also indicate the influence of a wind driven large-scale atmospheric process that alters locally the SBB and near-offshore region wind stress field and consequently causes interannual variability in the upper layer ocean volume transports. A strengthening of the southward flow in 25°S and 30°S was observed. The deep layer ocean volume transport in the three monitored sections indicates a potential dominance of other remote ocean processes. A small time lag between the integrated meridional volume transports changes in each monitored zonal section was observed.

Simulation of Large Scale KDP Crystal Polishing by Computer Controlled Micro-Nano Deliquescence

2012 ◽  
Vol 497 ◽  
pp. 165-169 ◽  
Author(s):  
He Ping Zhang ◽  
Dong Ming Guo ◽  
Xu Wang ◽  
Hang Gao
Keyword(s):  
Large Scale ◽  
Surface Condition ◽  
Single Point ◽  
Damage Threshold ◽  
Diamond Turning ◽  
Water Soluble ◽  
Optical Elements ◽  
Kdp Crystal ◽  
Computer Controlled ◽  
Laser Induced Damage

Although Single Point Diamond Turning (SPDT) can do pretty well in optical surfacing of large scale KDP crystal, both the surface accuracy and integrity are considerably high; meanwhile as the defects of micro-waveness and stress are inevitable, the laser-induced damage threshold of KDP optical elements after SPDT still cannot be satisfied. Because of the characters of deliquescent and water-soluble, the process of computer controlled Micro-nano deliquescence is attempted to remove the residual micro-waveness on KDP surface after SPDT. Based on the assumption of Preston and the characters of Micro-nano deliquescence, the model of material removal ratio is suggested, the dwell time for ascertained KDP surface is solved, the processing of computer controlled Micro-nano deliquescence is simulated and the processed surface condition on theory is obtained. Besides, the influences of different parameters on the surfacing efficiency and accuracy are analyzed. Finally, three polishing tracks are comparatively analyzed. The simulation results are quite important in guiding the experimental polishing of large scale KDP by computer controlled Micro-nano deliquescence

Assessment of the technical condition of underground structures of the largest hydroelectric power station in the North Caucasus, the Chirkeyskaya HPP

2021 ◽  
Vol 18 (3) ◽  
pp. 410-420
Author(s):  
Vladimir N. KAVKAZKY ◽  
◽  
Yana V. MEL’NIK ◽  
Alexey P. LEIKIN ◽  
Andrey V. BENIN ◽  
...  
Keyword(s):  
Large Scale ◽  
Practical Importance ◽  
Hydroelectric Power Plant ◽  
Technical Condition ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Underground Structures ◽  
North Caucasus ◽  
The Caucasus ◽  
The North

Objective: Chirkeyskaya HPP is by far the most powerful hydroelectric power plant in the North Caucasus with the highest arched dam in Russia and the second highest dam in the country after the Sayano-Shushenskaya HPP. This explains why it is called the pearl of the Caucasus. Methods: For the operation and maintenance of this unique structure, a large-scale complex of underground structures for various purposes was built, the technical condition of which must be constantly monitored. To carry out work on the survey of underground structures, the management of the design and survey institute of JSC “Lengidroproekt” decided to attract specialists from the Department of Tunnels and Subways and the Test Center “Strength” of Emperor Alexander I Petersburg State Transport University. The work was successfully carried out at the end of 2015. Results: The safety of underground structures was objectively assessed. Recommendations for the repair and further comprehensive reconstruction of the Chirkeyskaya HPP have been developed. Practical importance: Carry out work on the survey of underground structures of Chirkeyskaya HPP is allowes elaborate of complex measures on safety from Chirkeyskaya HPP.

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