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多相位改进型R-2R梯形DAC电路
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作者 马国胜 严晓兰 《电气电子教学学报》 2001年第2期48-49,共2页
介绍一种多相位改进型R-2R梯形DAC电路,它适合于ASIC或混合设计的梯形DAC电路,使许多应用电路中所使用的传统的CMOS多相DAC电路中元件更少,微调程序更简单。
关键词 r-2R梯形电 多相位数/模变换器 解码网络
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路液稳定土在公路提档升级工程中的应用研究
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作者 张明 李庆辉 +1 位作者 饶昌智 刘云 《建材发展导向》 2022年第20期15-18,共4页
为研究路液新型固化剂(路液R-1000)稳定路基土体的工程特性,分析路液R-1000固化土体的机理,在一级公路S359嘉鱼县试验段开展应用测试。测试获取原状土体的液塑限、承载比等指标,采用不同路液掺量和不同固化材料配比固化土体获得最经济... 为研究路液新型固化剂(路液R-1000)稳定路基土体的工程特性,分析路液R-1000固化土体的机理,在一级公路S359嘉鱼县试验段开展应用测试。测试获取原状土体的液塑限、承载比等指标,采用不同路液掺量和不同固化材料配比固化土体获得最经济的配比。结合施工工艺测试固化后土体的力学指标。试验表明:新型路液土壤固化剂稳定特殊土路基完全满足设计要求,并取得较好的经济效益。 展开更多
关键词 r-1000 土壤固化剂 固化机理 基加固 无侧限抗压强度
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弦图的L(3,2,1)-标号(英文) 被引量:1
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作者 袁万莲 翟明清 《运筹学学报》 CSCD 2010年第3期48-54,共7页
图G的一个L(3,2,1)-标号是指从V(G)到非负整数集的一个映射f,满足:当d_G(u,u)=1时,|f(u)-f(v)|≥3;当d_G(u,v)=2时,|f(u)-f(v)|≥2;当d_G(u,v)=1时,|f(u)-f(v)|≥1.L(3,2,1)-标号问题就是确定出最小的整数λ_3(G)使得G存在最大标号不超... 图G的一个L(3,2,1)-标号是指从V(G)到非负整数集的一个映射f,满足:当d_G(u,u)=1时,|f(u)-f(v)|≥3;当d_G(u,v)=2时,|f(u)-f(v)|≥2;当d_G(u,v)=1时,|f(u)-f(v)|≥1.L(3,2,1)-标号问题就是确定出最小的整数λ_3(G)使得G存在最大标号不超过该数的L(3,2,1)-标号.本文研究了弦图的L(3,2,1)-标号问题,获得了弦图及其一些子类,如扇,r-路,r-树等的λ_3数的界. 展开更多
关键词 运筹学 频率分配问题 L(3 2 1)-标号 弦图 r-路 r-
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Edge span of L(d,1)-labeling on some graphs
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作者 冯桂珍 宋增民 《Journal of Southeast University(English Edition)》 EI CAS 2005年第1期111-114,共4页
Given a graph G and a positive integer d, an L( d, 1) -labeling of G is afunction / that assigns to each vertex of G a non-negative integer such that |f(u)-f (v) | >=d ifd_c(u, v) =1;|f(u)-f(v) | >=1 if d_c(u, v... Given a graph G and a positive integer d, an L( d, 1) -labeling of G is afunction / that assigns to each vertex of G a non-negative integer such that |f(u)-f (v) | >=d ifd_c(u, v) =1;|f(u)-f(v) | >=1 if d_c(u, v) =2. The L(d, 1)-labeling number of G, lambda_d(G) is theminimum range span of labels over all such labelings, which is motivated by the channel assignmentproblem. We consider the question of finding the minimum edge span beta_d( G) of this labeling.Several classes of graphs such as cycles, trees, complete k-partite graphs, chordal graphs includingtriangular lattice and square lattice which are important to a telecommunication problem arestudied, and exact values are given. 展开更多
关键词 L(d 1)-labeling edge span triangular lattice square lattice choralgraphs r-path
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Identification of Sustainability Indicators and Evaluation of Transportation Corridors during Construction Using Fuzzy VIKOR Method
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作者 Shishir Bansal Sameer Verma Santosh K. Singh 《Journal of Civil Engineering and Architecture》 2015年第10期1217-1228,共12页
Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most... Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most commonly accepted as the three pillars of sustainability. In this paper, various sustainability indicators have been identified during the construction stage for elevated transportation corridors and thereafter classified under various categories. Using fuzzy VIKOR technique, sustainability evaluation of transportation corridors is made on two selected project sites of two different government organizations using various identified sustainability indicators, i.e., a 3.2-km long elevated road project under construction from Vikaspuri to Meerabagh in West Delhi by PWD (Public Works Department) and the metro rail elevated corridor (part) from Punjabi Bagh to Mayapuri as a part of Phase 3, Line 7 by DMRC (Delhi Metro Rail Corporation). The study is made at both sites in the midst of the construction period and it is identified that during the construction stage, the sustainability of these transportation corridors is just not limited to three pillars, but in actuality, it is much beyond that. From the study, it is inferred that the metro rail elevated corridor is a more sustainable corridor, in the context of the identified sustainability indicators. 展开更多
关键词 Sustainability indicators elevated corridors metro corridor GOVERNANCE inner engineering fuzzy VIKOR method.
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On the criteria to create a susceptibility map to debris flow at a regional scale using Flow-R 被引量:2
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作者 PASTORELLO Roberta MICHELINI Tamara D'AGOSTINO Vincenzo 《Journal of Mountain Science》 SCIE CSCD 2017年第4期621-635,共15页
Studies on susceptibility to debris flows at regional scale (ioo-looo km2) are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography,... Studies on susceptibility to debris flows at regional scale (ioo-looo km2) are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography, can be used to predict susceptible areas rapidly while necessitating few input data. In this research, Flow-R model is implemented to create the susceptibility map for the debris flow of the Vizze Valley (BZ, North-Eastern Italy; 134 km^2). The analysis considers the model application at local scale for three sub-catchments and then it explores the model upsealing at the regional scale by verifying two methods to generate the source areas of debris-flow initiation. Using data of an extreme event occurred in the Vizze Valley (4 August 2012) and historical information, the modeling verification highlights that the propagation parameters are relatively simple to set in order to obtain correct runout distances. A double DTM filtering - using a threshold for the upslope contributing area (0.1 km^2) and a threshold for the terrain-slope angle (15°) provides a satisfactory prediction of source areas and susceptibility map within the geological conditions of the Vizze Valley. 展开更多
关键词 Debris flow Susceptibility map Flow-R Triggering areas Regional scale Alpine valley
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Tropospheric Scintillation Estimation Using 10 Years Meteorological Data
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作者 Muhammad Tahir PIAO Yan +1 位作者 Muhammad Aslam Azizur Rahim 《China Communications》 SCIE CSCD 2015年第3期43-49,共7页
This paper presents estimation of tropospheric scintillation based on ITU-R model from previous 10 years meteorological data.Scintillation As(p) is critical in designing of microwave links for achieving optimal perfor... This paper presents estimation of tropospheric scintillation based on ITU-R model from previous 10 years meteorological data.Scintillation As(p) is critical in designing of microwave links for achieving optimal performance.There are many phenomenons that cause degradation to signal during transmission through the earth's atmosphere one of them is scintillation.Scintillation estimation is based on measurements of surface temperature T and relative humidity RH.Input parameter for ITU-R scintillation estimation model is the monthly average of wet part of refractivity Nwet.MATLAB software tool is employed to show the results for tropospheric scintillation in various seasons for time percentage p and frequencies ranging from 4GHz to 20 GHz. 展开更多
关键词 troposphere scintillation ITU-R fading meteorology
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