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微型计算机 1998年第10期18卷 82-83页

作者：衰哥

Landscape Formation and Protection of the Hukou waterfall

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Journal of Landscape Research 2019年第3期11卷 89-92页

作者： WANG Junkang College of Urban and Environmental Sciences Peking University

Establishing geoparks is an effective approach to protect natural resources and promote local tourism industry. The national geopark of the Hukou waterfall is an important geopark which attracts more than 2 million tourists per year. The Hukou waterfall is formed by combination of multiple knickpoints due to the longitudinal profile analysis. Like other waterfalls in the world, the Hukou waterfall will disappear in the future. Considering the mechanisms of waterfall evolution, this paper suggests establishing control engineering, preserving the water and soil in nearby region, and reinforcing the structure of waterfall to preserve the landscape of waterfall.

关键词： Geoparks The Hukou waterfall Formation and evolution Landscape preservation

Regional- to local-scale controls on waterfalls in Rocky Mountain National Park,Colorado

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Journal of Mountain Science 2020年第8期17卷 1874-1890页

作者： Jose A.ORTEGA-BECERRIL Bridget LIVERS Ellen WOHL Department of Geology and Geochemistry Autonomous University of MadridMadrid.28049Spain Department of Natural Resource Ecology and Management Iowa State UniversityAmesLA 50011 USA Department of Geosciences Colorado State UniversityFort CollinsCO 80523-1482USA

Previous work on the eastern side of Rocky Mountain National Park(RMNP),Colorado indicated correlations among waterfall location,waterfall morphology,and the characteristics of bedrock *** of waterfalls on the western side of the national park do not correlate as strongly with joint *** river profiles on the western side are less concave and waterfalls account for a greater proportion of the total elevation *** interpret these differences to result from more widely spaced joints,lithological differences,and complex glacial *** results demonstrate that waterfall shape and typology may change due to both local and regional controls operating in a mountain *** regions had alpine valley glaciers,but continued landscape evolution via fluvial erosion has developed waterfalls with diverse locations and morphologies that reflect the influences of glacial deposits,bedrock erosional resistance,and joint geometry.

关键词： waterfall Rocky Mountain National Park Knickpoint Bedrock Mountain stream regional-scale controls

Microtopographic modification conserves urban wetland water quality by increasing the dissolved oxygen in the wet season

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Journal of Environmental Sciences 2020年第1期32卷 71-81页

作者： Yali Liu Jianqing Du Panpan Hu Mingzhu Ma Dan Hu State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Enuironmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Microtopography affects hydrological processes and forms different *** previous study uncovered that riparian zone microtopography created various microhabitats with different soil environments and runoff-infiltration ***,how riparian microtopography and microtopography within the water area(waterfall and tributary)affects downstream water quality remains ***,water samples were taken almost monthly in both the main stream and the tributary,before and after waterfalls,and near the bottom of three microtopographic types from June 2016 to March *** with the dry season,the fact that water quality worsened in the wet season and that there were positive correlations for nitrate(NO3-)between water and the corresponding soil samples suggested that the riparian-soil environment affected the adjacent water quality mainly in the wet ***,riparian microtopography did not influence water quality downstream because of the low rainfall frequency and the weak leaching process due to plant *** the wet season,both the tributary and the waterfall increased the dissolved oxygen in the water body and,therefore,lowered the risk of *** tributary has two pathways for improving the water quality,by increased disturbance and flow velocity,while the waterfall only has the ***,such effects were not significant in the dry *** conclude that the application of microtopographic modification is useful in maintaining urban wetland water quality in wet seasons.

关键词： Microtopographic modification Wetland water quality Tributary waterfall Eutrophication

NUMERICAL STUDY ON EFFECT OF WAVING BED ON THE SURFACE WAVE

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Journal of Hydrodynamics 2006年第4期18卷 464-468页

作者： WU Zheng-ren CHENG You-liang WANG Song-ling School of Energy and Power Engineering North China Electric Power University Baoding 071003 China

The effect of the waving bed on the surface wave was investigated. The wave equation was reduced from the potential flow theory with the perturbation technique, and then was solved by using the pseudo-spectral method. The waterfall of the surface wave was simulated with the Matlab. It is shown that for the waving bed, an additional harmonic wave appears on the surface together with the solitary wave existing for the non-waving bed, and two kinds of waves do not interfere with each other. With the development of time, the waveform for the waving bed is kept invariable, and just the amplitude is reduced gradually. Wave-breaking phenomenon for the non-waving bed does not appear, so the waving bed seems useful to prevent the breaking of the wave.

关键词： waving bed pseudo-spectral method solitary wave wave breaking waterfall

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mesh结构NoC的时钟网络研究

西北工业大学学报 2006年第4期24卷 472-476页

作者：周国昌沈绪榜西北工业大学计算机学院陕西西安710072

分析了m esh结构N oC的3种时钟网络,针对同步时钟网络瞬时功耗大,非对称瀑布网络(w aterfall)和对称瀑布网络通信延迟大的弊端,提出并设计了一种混合结构的时钟网络。并以4×4混合结构时钟网络为例,计算得出该时钟网络的最大通信延迟为... 详细信息

分析了m esh结构N oC的3种时钟网络,针对同步时钟网络瞬时功耗大,非对称瀑布网络(w aterfall)和对称瀑布网络通信延迟大的弊端,提出并设计了一种混合结构的时钟网络。并以4×4混合结构时钟网络为例,计算得出该时钟网络的最大通信延迟为非对称瀑布网络的12.5%,局部单方向数据流的通信延迟约为对称瀑布网络的25%,芯片的瞬时功耗约为同步时钟网络的50%。

关键词： NoC 时钟分布网络 waterfall 混合结构时钟网络

Stability Analysis of Cliff Face around Kegon Falls in Nikko, Eastern Japan: An Implication to Its Erosional Mechanisms

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International Journal of Geosciences 2013年第6期4卷 8-16页

作者： Yuichi S. Hayakawa Center for Spatial Information Science The University of Tokyo Chiba Japan

A waterfall highlights the locus of active fluvial erosion of bedrock, and its mechanism has been the subject of several studies;however, erosional processes remain to be clarified for specific rock structures composing a waterfall. Herein, the detailed morphology of cliffs around a waterfall is examined by a terrestrial laser scanning (TLS) approach to analyze erosional processes occurring in the cliffs. The study site is Kegon Falls in Japan, which has a vertical drop of surface water from the top of its cliff and groundwater outflows from its lower portion. The entire cliff is mostly overhanging and minor rockfalls are often observed. The latest major rockfall occurred in 1986, causing an approximate 8-m upstream shift of the waterfall lip. From the point cloud obtained by TLS measurement, a digital elevation model on a vertical plane was generated, and cross-sectional profiles were extracted. A distinct 5- to 10-m depression was found at the bottom of the upper andesite layer of the waterfall cliff, which appears to have been formed by freeze-thaw and wet-dry weathering following the upstream shift of the surface water drop. Stability analysis of the waterfall cliff with an undercutting notch indicates that the igneous rock composing the cliff is sufficiently strong to maintain its current overhanging shape and that catastrophic collapse of the entire waterfall face rarely occurs. Following the formation of the depression, the upper cliff face appears to have been gradually eroded by gravitational collapses of relatively small blocks bounded by columnar and platy joints.

关键词： Bedrock Erosion Knickpoint waterfall Recession Terrestrial Laser Scanning

Quintessence of Traditional and Agile Requirement Engineering

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Journal of Software Engineering and Applications 2016年第3期9卷 63-70页

作者： Jalil Abbas School of Computing and Information Sciences Imperial College of Business Studies Lahore Pakistan

Requirement gathering for software development project is the most crucial stage and thus requirement engineering (RE) occupies the chief position in the software development. Countless techniques concerning the RE processes exist to make sure the requirements are coherent, compact and complete in all respects. In this way different aspects of RE are dissected and detailed upon. A comparison of RE in Agile and RE in waterfall is expatiated and on the basis of the literature survey the overall Agile RE process is accumulated. Agile being a technique produces high quality software in relatively less time as compared to the conventional waterfall methodology. The paramount objective of this study is to take lessons from RE that Agile method may consider, if quality being the cardinal concern. The study is patterned on the survey of the previous research reported in the coexisting literature and the practices which are being pursued in the area.

关键词： Requirement Engineering waterfall Software Development Life Cycle Agile Software Development Elicitation

Agile Development: Exploring What Practitioners Want to Know

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Journal of Software Engineering and Applications 2018年第1期11卷 1-11页

作者： Nanda C. Surendra Salman Nazir Management Information Systems College of Business & Economics West Virginia University Morgantown WV USA

Agile development has its origins and roots in practice rather than academia. Hence, in this research, we go to the practitioners’ world to explore what they want to know about Agile development. We conducted our study using a multi-methodological approach, a combination of a survey and an interpretive case study. We learned that Agile development is yet to reach a mature phase with: a) relatively limited numbers of experienced Agile practitioners;b) a large number of software developers who were trained in plan-based waterfall development trying to transition to Agile;c) some companies and practitioners continuing to be skeptical of the benefits of Agile development over plan-based development;and d) tools in the process of being developed to support Agile development. Based on those factors, we learned that practitioners are wanting to find answers to the following questions: a) What should good Agile practitioners and teams know and do? b) How to train developers and teams to become good Agile practitioners? c) How to transition from plan-driven waterfall development to Agile development? d) What tools are available to practice Agile development? How to use them to support Agile practices? The following are the answers we derived from our interpretive case study for the above four questions: a) Good Agile practitioners define their job in terms of the client’s mission;they don’t define their jobs as analysts, designers, programmers, testers, or project managers;b) For training, Agile practices such as test-driven development and continuous integration are best understood not in theory but by the act of doing;for organizational adoption of Agile development, Agile practices should be used not only in software development but encouraged in all functional areas;c) The best way to introduce a plan-based waterfall practitioner to Agile is to have him think of Agile in terms of something familiar, as a series of mini-waterfalls that have very quick iterations;d) Simple

关键词： Agile Development Case Study Research Agile Practice Scrum Agile Teams Software Development waterfall Development

Effects of Clearance between Rotor and Ground on the Performance of an Open Cross-Flow-Type Nano-Hydraulic Turbine

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Journal of Energy and Power Engineering 2016年第8期10卷 465-473页

作者： Tomomi Uchiyama Shouhei Mizoguchi Shouichiro Iio Yusuke Katayama Toshihiko Ikeda Institute for Materials and Systems for Sustainability Nagoya University Nagoya 464-8603 Japan Toyota Motor Corporation Toyota 471-8571 Japan Faculty of Engineering Shinshu University Nagano 380-8553 Japan

Flows through an open cross-flow-type nano-hydraulic turbine are numerically simulated to investigate the effects of the clearance Hc between the rotor and the ground on the turbine performance. A two-dimensional particle method is employed, which was successfully used for flow simulations of impulse-type and open cross-flow-type nano-hydraulic turbines in the authors＇ previous works. When the clearance Hc is smaller than a critical value, the simulated turbine performance decreases with decreasing Hc, in good agreement with the experiment. The simulations make it clear that such a reduction of turbine performance is attributable to an increase in the circumferential component of the water velocity at the rotor outlet. The simulations also demonstrate that the effect of the tip speed ratio of the rotor on the relation between Hc and turbine performance can be analyzed.

关键词： Nano-hydraulic turbine computer simulation waterfall particle method.