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Shear properties of cemented rockfills

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 635-644页

作者： bob A.Lingga derek B.Apel department of Civil and Environmental Engineering School of Mining and Petroleum University of Alberta

Application of cemented rockfilling to underground mining could not be separated from the corresponding backfill’s shear strength properties. The shear of cemented rockfill(CRF)-rock wall and the shear interaction occurring within CRFs both have some disadvantageous failure chances. In this study,we tried to investigate the complete shear properties of CRFs using direct shear and triaxial tests of cemented granite rockfill. Large-scale triaxial testing was held to accommodate the large CRF *** shear testing on the prepared flat and smooth surfaces was assessed with brief conversions and their corrections were used to approximate the shear strength envelopes of CRF joint interfaces. Two types of CRFs with the same aggregate size and distribution but different unconfined compressive strengths(UCSs) due to different mixture designs indicated insignificant differences between their basic friction angles, and also their asperity inclination angles. Nevertheless, investigation between direct shear test and triaxial test showed that the specimen with higher UCS tended to have a slightly lower friction angle but a higher cohesion than the other one.

关键词： Cemented rockfill (CRF) Shear tests Shear strength Friction angle Cohesion Backfill interface

An activated variable parameter gradient‐based neural network for time‐variant constrained quadratic programming and its applications

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CAAI Transactions on Intelligence Technology 2023年第3期8卷 670-679页

作者： Guancheng Wang Zhihao Hao Haisheng Li bob Zhang PAMI Research Group Department of Computer and Information ScienceUniversity of MacaoTaipaMacaoChina China Industrial Control Systems Cyber Emergency Response Team BeijingChina Beijing Key Laboratory of Big Data Technology for Food Safety Beijing Technology and Business UniversityBeijingChina

This study proposes a novel gradient‐based neural network model with an activated variable parameter,named as the activated variable parameter gradient‐based neural network(AVPGNN)model,to solve time‐varying constrained quadratic programming(TVCQP)*** with the existing models,the AVPGNN model has the following advantages:(1)avoids the matrix inverse,which can significantly reduce the computing complexity;(2)introduces the time‐derivative of the time‐varying param-eters in the TVCQP problem by adding an activated variable parameter,enabling the AVPGNN model to achieve a predictive calculation that achieves zero residual error in theory;(3)adopts the activation function to accelerate the convergence *** solve the TVCQP problem with the AVPGNN model,the TVCQP problem is transformed into a non‐linear equation with a non‐linear compensation problem function based on the Karush Kuhn Tucker ***,a variable parameter with an activation function is employed to design the AVPGNN *** accuracy and convergence rate of the AVPGNN model are rigorously analysed in ***,numerical experiments are also executed to demonstrate the effectiveness and superiority of the proposed ***,to explore the feasibility of the AVPGNN model,appli-cations to the motion planning of a robotic manipulator and the portfolio selection of marketed securities are illustrated.

关键词： computational intelligence mathematics computing optimisation

Assessing adaptability and response of vegetation to glacier recession in the afro-alpine moorland terrestrial ecosystem of Rwenzori Mountains

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Journal of Mountain Science 2016年第9期13卷 1584-1597页

作者： Tonny J.OYANA bob R.NAKILEZA Spatial Analytics and Informatics Core Department of Preventive Medicine The University of Tennessee Health Science Center Mountain Resource Centre Department of Geography Geo-informatics and Climate Sciences Makerere University

The objective of this study was to explore vegetation adaptability in a changing afro-alpine moorland terrestrial ecosystem on Mt. Rwenzori and to determine whether there were any links with response of vegetation to glacier recession. We analyzed the composition and distribution of plant species in relation to soils, geomorphic processes, and landscape positions in the Alpine zone. To accomplish this objective, archival data sources and published reports for this ecosystem were reviewed. A field trip was conducted in 2010 to study in detail seven vegetation sampling plots that were systematically selected using GIS maps and a nested-quadrat sampling design framework along an altitudinal gradient in the lower and upper alpine zones. Using these sampling plots, 105 vegetation and 13 soil samples were assessed in the alpine zone. Soil samples were taken for laboratory testing and analysis. The results show statistically significant differences in pH, OM, N, P, Ca, Mg, and K pools between soils samples drawn from the lower and upper alpine sites （p 〈 0.0033）. Furthermore, we observed a significant vegetation formation with numerous structural forms, but there was a limited diversity of speeies. The most significant forms included Alchemilla carpets, Bogs, dendrosenecio woodland, and Scree slopes. The lower alpine area （3500-3900 masl） had a more diverse plant species than other areas, especially Alchemilla argyrophylla and dendrosenecio adnivalis species that were evident due to well-drained deeper soils. The Alchemilla subnivalis were evident at a higher altitude of above 4000 mask Shifts in the Astareeeae （e.g. Senecio species） were particularly prominent even on recently deglaciated areas. The spatial variations of species distribution, structure, and composition suggest there are serious implications in terms of ecosystem adaptability, resilience, and stability that require further evaluation.

关键词： Alpine Plant species Species abundance Tropical afro-alpine ecosystems Afro-alpinemoorland

Integrated Risk Identification, Analysis, and Assessment:A Dynamic Household Economy Analysis Methodology and Example

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International Journal of Disaster Risk Science 2013年第2期4卷 77-88页

作者： bob Alexander Linda J.Cox Junko Mochizuki Rural Livelihood Risk Management Consulting P.O.Box 1251HonoluluHI 96807USA department of Natural Resource and Environmental Management University of Hawai`i at ManoaHonoluluHI 96822USA

Many methodologies identify, analyze, and assess static risks to quantify potential disaster losses based on past and current events. Static methodologies will not, however, capture how climate change and adaptation are rapidly affecting the natural and social systems in many areas. Local and global changes such as those associated with development investments, livelihood pressures, political stability, and demographic trends are also affecting many areas, especially in emerging economies. Risk identification, analysis, and assessment methodologies must integrate all changes dynamically so that risk reduction and development decisions can be based on future needs. After a theoretical explanation of how to integrate dynamic changes, a static Household Economy Analysis(HEA) completed for a rapidly changing area of East Timor was altered using current trends to make the analysis more dynamic. Some inherent difficulties exist with a more dynamic approach and recommendations for overcoming them are presented. Research, government, and nongovernment personnel interested in integrated approaches to risk reduction and development decision-making in areas subject to rapid change will find the study useful.

关键词： integrate disaster interested

Target toxicity design for phase Ⅰ dose-finding

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Statistical Theory and Related Fields 2021年第2期5卷 149-161页

作者： Wenchuan Guo bob Zhong Global Biometric Sciences Bristol-Myers Squibb CompanyPenningtonNJUSA Nektar Therapeutics San FranciscoCAUSA

We propose a new two-/three-stage dose-finding design called Target Toxicity(TT)for phase Ⅰ clinical trials,where we link the decision rules in the dose-finding process with the conclusions from a hypothesis *** power to detect excessive toxicity is also *** solves the problem of why the minimal number of patients is needed for the selected dose *** method provides a statistical explanation of traditional‘3+3’design using frequentist *** proposed method is very flexible and it incorporates other interval-based decision rules through different parameter *** provide the decision tables to guide investigators when to decrease,increase or repeat a dose for next cohort of *** experiments were conducted to compare the performance of the proposed method with other dose-finding designs.A free open source R package tsdf is available on *** is dedicated to deriving two-/three-stage design decision tables and perform dose-finding simulations.

关键词： Group-sequential-like designs dose-finding phaseⅠ MTD recommended phaseⅡdoses power

Analysis and Applications of Session Initiation Protocol (SIP) in Internet Telephony

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The Journal of China Universities of Posts and Telecommunications 2005年第1期12卷 70-75页

作者： WARFIELD bob department of Electrical & Electronic Engineering The University of Melbourne Melbourne Victoria 3010 Australia

Session Initiation Protocol (SIP) is a key technology in the Internettelephony or Voice-over- IP (VoIP), also it is an important signaling technology in the nextgeneration multimedia communications. Based on the comparison between SIP and H. 323 technology,this paper concludes the advantages of SIP. Then grounded on the major components and theirinteraction, it analyzes the mechanism and features of the Internet telephony based on SIP. Finally,it discusses the disadvantages of SIP and provides the emphasis of future work.

关键词： SIP H. 323 internet telephony interoperability mobility

从振藩咏春到截拳道:李小龙的现代中国武道进化史

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中华武术 2024年第2期 16-23页

作者：郝钢(翻译) 周靖昆(翻译) 鲍勃·兰德斯不详

在最初发表于2008年5月期《黑带》采访文章的前言介绍中,原采访者鲍勃·兰德斯写道:“过去十年间,截拳道世界发生了很多事……黄锦铭师傅是主流认可的李小龙截拳道的正统传人,我们应该把他的口述历史记录下来。”遗憾的是,在持续采访过... 详细信息

在最初发表于2008年5月期《黑带》采访文章的前言介绍中,原采访者鲍勃·兰德斯写道:“过去十年间,截拳道世界发生了很多事……黄锦铭师傅是主流认可的李小龙截拳道的正统传人,我们应该把他的口述历史记录下来。”遗憾的是,在持续采访过程中,黄锦铭师傅于2010年11月离世。鲍勃·兰德斯原计划是通过提问,解答那些长期困扰着武术家们,且未经黄师傅及其弟子回答过的,有关李小龙和截拳道的问题。黄锦铭师傅当时70岁,却仍致力于通过系统训练增强他的身体机能,加深对截拳道的体悟。他毕生对武术,特别是李小龙截拳道的传承贡献,使他在2006年荣膺黑带名人堂年度人物。采访过程中,黄师傅依然不知疲倦地遍访全球,教授学自李小龙的原传截拳道的科学格斗体系的精髓,籍此缅怀与他亦师亦友的李小龙。有鉴于此,《黑带》杂志2014年9月号重温整个经典采访,以纪念李小龙的学生和朋友——黄锦铭。

关键词：李小龙截拳道采访者口述历史亦师亦友身体机能黄锦武术家

Single-arm phase II three-outcome designs with handling of over-running/under-running

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Statistical Theory and Related Fields 2023年第4期7卷 276-286页

作者： Wenchuan Guo Jianan Hui bob Zhong Seagen Inc. BothellWAUSA Servier Pharmaceuticals BostonMAUSA Regeneron Pharmaceuticals TarrytownNYUSA

Phase II clinical trials are commonly conducted as pilot studies to evaluate the efficacy and safety of the investigational drug in the targeted patient population with the disease or condition to be treated or *** designing such a trial considering efficacy conclusions,people natu-rally think as follows:if efficacy evidence is very strong,a go decision should be made;if efficacy evidence is very weak,a no-go decision should be made;if the efficacy evidence is neither strong nor weak,no decision can be made(inconclusive).The designs presented in this paper match this natural thinking process with go/no-go/inconclusive *** two-/three-stage designs are developed with three ***,a general approach based on conditional error function is implemented such that new decision boundaries can be calculated to handle mid-course sample size change which results in either‘over-running’or‘under-running’and ensure the control of overall type I error.A free open-source R package tsdf that calculates the proposed two-/three-stage designs is available on CRAN.

关键词： Phase II trials two-stage and three-stage designs go/no-go/inconclusive outcomes asymmetric alpha alpha spending optimal designs over-running and under-running

Assessment of digital image correlation method in determining large scale cemented rockfill strains

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International Journal of Mining Science and Technology 2019年第5期29卷 771-776页

作者： bob A.Lingga derek B.Apel Mohammadali Sepehri Yuanyuan Pu School of Mining and Petroleum Engineering University of AlbertaEdmonton T6G 2W2Canada

A conventional contact method(using linear transducers)and a non-contact method are deployed to measure the axial and lateral deformations of large scale cylindrical cemented rockfill *** works incorporating two pinhole cameras to create one stereovision by digital image correlation shows that the non-contact method is as reliable for testing large cylindrical specimens as measurements done by using linear variable displacement transformer and string *** this particular large specimen,the experiment resulted in the acceptable mean difference between lateral strain using both methods is 5.1 percent,and 14.5 percent for the axial *** occurrence is inevitable due to the heterogeneity of the concrete system and the placement of the monitoring point in digital image correlation method,although the comparison of stress-strain relationship in both methods still indicates a *** on the results of the present experiments,the authors recommend the noncontact method for a detailed investigation of the material behavior during the uniaxial compressive strength *** field strain measurement enables this digital method to examine local strains near cracks at any point,a very useful tool for studying material deformation behavior.

关键词： Experimental testing Cemented rockfill Digital image correlation Strain measurement Mine backfill