Macro Layout Research Articles

Establishment and Application of Spatial Distribution Model of Roof Greening Based on GIS Technology

The stage from the beginning of the 21st century to now is the stage of the scale development of roof greening(RG) in China. With the continuous progress of urban construction, on the one hand, the ecological environment is deteriorating, on the other hand, the available green space in the urban center area becomes more and more scarce. The development of this contradiction promotes the rapid development of RG. RG plays an important role in enriching urban landscape, increasing urban green quantity, reducing urban heat island effect, conserving rainwater and reducing temperature, and creating a new green space for the city, including leisure, entertainment and ecology, and improving urban ecological landscape. This paper mainly studies the establishment and application of spatial distribution(SD) model of RG Based on GIS technology. Through understanding the SD design of RG, the paper investigates and analyzes the status quo of green space of roof, macro layout and the integration of multiple functional spaces. This paper studies and establishes a multiobjective optimization model of SD of RG, and analyzes the purification effect of RG on rainwater pollutants and the overall performance of ecosystem service equity. The results show that 26.31% of the people think that the degree of RG is insufficient, and 5.14% think that RG is scarce. In the cognition of the status of RG space, 12.41% of people don't care about RG, 8.69% think it is face engineering, and even 9.31% think it is waste of resources, which indicates that the promotion of RG needs to be improved.

三峡水库涪陵-奉节段消落带优势草本植物生态位与种间联结性研究

PDF HTML阅读 XML下载 导出引用 引用提醒 三峡水库涪陵-奉节段消落带优势草本植物生态位与种间联结性研究 DOI: 10.5846/stxb202011162953 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学青年基金面上项目（31270451）；三峡库区水环境演变与污染防治重点实验室开放基金项目（WETKL2012MS-07）；国家自然科学青年基金（41902024）；重庆市科委面上项目（cstc2019jcyj-msxmX0656） Niche and interspecific association of dominant herbaceous plants in the water-level-fluctuating zone of Fuling-Fengjie section of the Three Gorges Reservoir Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:参照相邻格子法对三峡水库中段（重庆市涪陵-奉节段消落带）地上植被进行调查，并运用生态位宽度、生态位重叠度、χ2检验等手段对优势草本植物生态位与种间联结性进行分析，能在一定程度上揭示三峡水库消落带优势草本植物的生态学特性、进而推测植被群落的演替趋势，以期为三峡水库消落带植被生态修复提供理论基础或参考建议。结果表明：（1）本次调查发现共有优势植物57种、隶属22科44属，其中狗牙根的生态位宽度最大、占绝对竞争优势。（2）在105个种对中，生态位相似比（Cih）≥0.50的种对有4个，生态位重叠值（Lih）≥0.50的种对有7个，种间相似性较小、竞争关系较弱。（3）χ2检验结果显示，优势植物种间正负联结比为1.33，正联结优势不明显；而Pearson与Spearman秩相关检验结果显示，种间正负联结比分别为0.54、0.75，负联结占优势。三种检验方式均表明，优势植物种间联结性较弱、稳定性相对较差、独立性相对较强。（4）种间联结系数（AC）≥0.60的种对数为7种，共同出现百分率（PC）≥0.7的种对数仅为1种。种间总体正联结性不强，物种趋于独立分布。（5）种间Pearson、Spearman秩相关检验与相应的Cih和Lih之间均呈显著正相关，表明种间正（负）关联越强、Cih和Lih越大（小）。（6）本文研究结果在一定程度上反映了三峡水库消落带植被退化生态系统现状，为最大程度提高消落带植物群落结构稳定性和物种多样性，针对小流域植被恢复与重建有如下参考建议：在整体上，可以采用以狗牙根（Cynodon dactylon（Linn.） Pers）、苍耳（Xanthium sibiricum）、鬼针草（Bidens pilosa L.）等为先锋植物，以狗尾草（Setaria viridis）、稗（Echinochloa crusgalli）、牛鞭草（Hemarthria altissima）等为伴生种的群落配置模式进行宏观布局；在局部上，可以采用稗（Echinochloa crusgalli）+苘麻（Abutilon theophrasti Medicus）、狗尾草（Setaria viridis）+黄花草木樨（Melilotus officinalis L.）、马唐（Digitaria sanguinalis）+水蓼（Polygonum hydropiper L.）等种对配置模式进行实地配置。 Abstract:This article refers to the adjacent grid method to investigate the aboveground vegetation in the middle section of the Three Gorges Reservoir (Fuling-Fengjie section of Chongqing City). We use niche width, niche overlap, χ2 test and other methods to compare the niche of dominant herbaceous plants, which could reveal the ecological characteristics of dominant herbaceous plants in the Three Gorges Reservoir water level fluctuating zone to a certain extent. Then, we infer the succession trend of plant community, so as to provide theoretical basis or reference suggestions for the ecological restoration of vegetation in the Three Gorges Reservoir water level fluctuating zone. The results showed that:(1) There were 57 plant species belonging to 22 families and 44 genera. The niche breadth of bermudagrass was the largest and occupied the absolute competitive advantage. (2) Among the 105 dominant plant species pairs studied, there were 4 species pairs with niche similarity ratio (Cih) ≥ 0.50 and 7 species pairs with niche overlap value (Lih) ≥ 0.50, indicating that the similarity between species was small and the competition was weak. (3) χ2 test results showed that the positive and negative association ratio of dominant plants was 1.33, indicating that the positive association advantage was not obvious. Pearson and Spearman rank correlation test showed that the positive and negative association ratio was 0.54 and 0.75, respectively, indicating that negative association was dominant. All the three tests showed that the interspecific association of dominant plants was weak, the stability was relatively poor and the independence was relatively strong. (4) The number of species with interspecific association coefficient (AC) ≥ 0.60 was 7 and the number of species with cooccurrence percentage (PC) ≥ 0.7 was only 1, indicating that the positive association between species was not strong and species tended to be independent. (5) Pearson and Spearman rank correlation tests showed a significantly positive correlation with Cih and Lih between species, indicating that the stronger the positive (negative) correlation, the greater the Cih and Lih. (6) In order to maximize the structural stability and species diversity of plant community in the Three Gorges Reservoir water-level-fluctuating zone, the following suggestions were put forward for vegetation restoration and reconstruction in small watershed:on the whole, a community configuration mode with Bermudagrass, Cocklebur, Bidens, etc. as the dominant plants, and Setaria, Barnyardgrass, and Virginia etc. as the companion species could be used for macro layout. In the local, the configuration mode of Echinochloa crusgalli+Abutilon bicolor, Setaria setifolia+Melilotus lutea, Digitaria tangutorum+Polygonum hydropiper etc. could be used for field configuration. 参考文献 相似文献 引证文献

A novel discrete–continuous material orientation optimization model for stiffness-based concurrent design of fiber composite

The cooperation of tailoring fiber angles and designing its macro layout is an excellent approach to improve the performance of composite structures and achieve lighter weight. This article proposes a novel discrete–continuous optimization model for the concurrent optimization of the macro structural topology and local fiber angle for the fiber-reinforced composite structure. Therein, the novel modeling consists of a two-step strategy, where the normal distribution function is adopted to form the discrete material interpolation scheme firstly and then the continuous angle design on fine angle subintervals is conducted. Because it requires the fixed discrete design variables regardless of the number of angle subintervals and simultaneously achieves the continuous fiber angle design, it can save computational cost and provide an infinite design domain. Furthermore, the subdividing angle interval reduces the risks of falling into the local optimum solution for continuous angle design. Besides, the fiber discontinuity may cause stress concentration and manufacturing problems in the intersection of discontinuous fiber paths. Therefore, a linear density technique is used to achieve fiber continuity. Finally, a concurrent topology optimization model is built based on the proposed novel model. And several numerical examples are well-organized and presented to illustrate the validity of the proposed model.

Concurrent design of the free damping structure for minimizing the frequency response in a broad frequency band

This article develops a multiscale topology optimization model for the free damping structure to optimize the microstructure of the damping material and its macro layout. The objective is to minimize structural response in a broad frequency gap subject to volume constraints on both macro and micro levels. To overcome the convergence difficulty caused by the sharp jumping of the harmonic response around structural eigenfrequencies and maintain high-precision integral, the Gauss Legendre integration method is adopted to calculate the integration of objective function. Based on the density-based method, the sensitivity analysis of the objective function and the constraint is deduced. The mode acceleration method is used to reduce computational cost and a modified threshold Heaviside projection method is used to obtain the clear black-and-white designs. Several numerical examples are investigated to demonstrate the validity of the proposed model.

Multiscale reliability-based topology optimization methodology for truss-like microstructures with unknown-but-bounded uncertainties

This paper introduces a new optimization framework to multiscale structures with unknown-but-bounded (UBB) uncertainties, where the optimal design is applied at two scales: the macroscale, i.e., the structural level, where the non-probabilistic reliability-based topology optimization (NRBTO) is conducted, and the microscale, i.e., the material level, where the non-probabilistic reliability-based design optimization (NRBDO) for truss-like cell dimensions is achieved. By combination of the homogenization method and interval mathematics, rules of macro–micro stiffness equivalence as well as interval bounds of macro displacement responses under specific micro structural settings can be first confirmed. For safety reasons, novel reliability definitions are respectively given for the double-level design, in which the offset factor with good differential properties is applied for the NRBTO and the matching factor derived from the improved rule of interval sorting is utilized for the NRBDO. To circumvent problems of large-scale variable updating in two-level optimization procedures, the adjoint-based vector in macro layout design as well as the particle swarm optimization (PSO) algorithm in micro parametric design are further discussed. The usage, effectiveness, and the superiority of the developed methodology are eventually demonstrated by two 3D engineering applications.

The Industrialization Experience of Scientific Results of HIRFL: Social Benefits, Regional Balanced Development,Government Support, Local Advantage

Heavy Ion Research Facility in Lanzhou (HIRFL) has attained important scientific goals, at the same time, the rising industrial chains represented by HIMM industry and sweet sorghum industry have formed growth pole and given an impetus to readjust and optimize the industrial structure of western region, to improve the sustainable development of the regional society and economy. Through the field research and interviews,analysis and summary are made regarding to the experience in Lanzhou on the layout and industrialization of scientific results of the large scientific facilities: the development planning and the top-level design should pay attention to bring the comprehensive benefits, especially the economic and social benefits, besides consideration of scientific goals. Because the large scientific facilities have additional aspects of the economic and social benefits,the macro layout should lay stress on the balance of regional development; many difficulties exist in the rusults transformation of the large scientific facilities, which can be the mark of high-end and advanced science and technology, such as high uncertainty, long investment recycle time, great risk and so on. Thus, government should set up the special project to support initial research and development and effectively reduce the risk of research and development in enterprise. The development in the comprehensive benefits of the large scientific facilities should combine the practical factors and make full use of the local advantage.

Potential of dynamic spectrum allocation in LTE macro networks

Abstract. In recent years Mobile Network Operators (MNOs) worldwide are extensively deploying LTE networks in different spectrum bands and utilising different bandwidth configurations. Initially, the deployment is coverage oriented with macro cells using the lower LTE spectrum bands. As the offered traffic (i.e. the requested traffic from the users) increases the LTE deployment evolves with macro cells expanded with additional capacity boosting LTE carriers in higher frequency bands complemented with micro or small cells in traffic hotspot areas. For MNOs it is crucial to use the LTE spectrum assets, as well as the installed network infrastructure, in the most cost efficient way. The dynamic spectrum allocation (DSA) aims at (de)activating the available LTE frequency carriers according to the temporal and spatial traffic variations in order to increase the overall LTE system performance in terms of total network capacity by reducing the interference. This paper evaluates the DSA potential of achieving the envisaged performance improvement and identifying in which system and traffic conditions the DSA should be deployed. A self-optimised network (SON) DSA algorithm is also proposed and evaluated. The evaluations have been carried out in a hexagonal and a realistic site-specific urban macro layout assuming a central traffic hotspot area surrounded with an area of lower traffic with a total size of approximately 8 × 8 km2. The results show that up to 47 % and up to 40 % possible DSA gains are achievable with regards to the carried system load (i.e. used resources) for homogenous traffic distribution with hexagonal layout and for realistic site-specific urban macro layout, respectively. The SON DSA algorithm evaluation in a realistic site-specific urban macro cell deployment scenario including realistic non-uniform spatial traffic distribution shows insignificant cell throughput (i.e. served traffic) performance gains. Nevertheless, in the SON DSA investigations, a gain of up to 25 % has been observed when analysing the resource utilisation in the non-hotspot cells.

Layout Decomposition and Legalization for Double-Patterning Technology

The use of multiple-patterning (MP) optical lithography for sub-20 nm technologies has inevitably become slow to adopt the next generation of lithography systems. The biggest technical challenge of MP is failure to reach a manufacturable layout-coloring solution, especially in dense layouts. This paper offers a post layout solution for the removal of conflicts, i.e., patterns that cannot be assigned to different masks without violating spacing rules. The proposed method essentially consists of three steps: 1) layout coloring; 2) exposure layers; 3) geometric rules definition; and 4) layout legalization using compaction and MP rules as constraints. The method is general and can be used for different MP technologies, including lithography-etch, lithography-etch double-patterning (DP), triple patterning/MP (i.e., multiple litho-etch steps), and self-aligned DP (SADP). For demonstration purposes, we apply the proposed method in this paper to remove conflicts in DP. We offer an O(n) layout-coloring heuristic algorithm for DP, which is up to 80× faster than the integer linear program-based approach. The conflict-removal problem is formulated as a linear program, which permits an extremely fast runtime (less than 1 min in real time for macro layouts). The method was tested on standard cells and macro layouts from a commercial 22-nm library designed without any MP awareness. For many cells, the method removes all conflicts without any area increase. For some complex cells and macros, the method still removes all conflicts but with a modest 6% average increase in area.

Area- and energy-efficient CORDIC accelerators in deep sub-micron CMOS technologies

Abstract. The COordinate Rotate DIgital Computer (CORDIC) algorithm is a well known versatile approach and is widely applied in today's SoCs for especially but not restricted to digital communications. Dedicated CORDIC blocks can be implemented in deep sub-micron CMOS technologies at very low area and energy costs and are attractive to be used as hardware accelerators for Application Specific Instruction Processors (ASIPs). Thereby, overcoming the well known energy vs. flexibility conflict. Optimizing Global Navigation Satellite System (GNSS) receivers to reduce the hardware complexity is an important research topic at present. In such receivers CORDIC accelerators can be used for digital baseband processing (fixed-point) and in Position-Velocity-Time estimation (floating-point). A micro architecture well suited to such applications is presented. This architecture is parameterized according to the wordlengths as well as the number of iterations and can be easily extended for floating point data format. Moreover, area can be traded for throughput by partially or even fully unrolling the iterations, whereby the degree of pipelining is organized with one CORDIC iteration per cycle. From the architectural description, the macro layout can be generated fully automatically using an in-house datapath generator tool. Since the adders and shifters play an important role in optimizing the CORDIC block, they must be carefully optimized for high area and energy efficiency in the underlying technology. So, for this purpose carry-select adders and logarithmic shifters have been chosen. Device dimensioning was automatically optimized with respect to dynamic and static power, area and performance using the in-house tool. The fully sequential CORDIC block for fixed-point digital baseband processing features a wordlength of 16 bits, requires 5232 transistors, which is implemented in a 40-nm CMOS technology and occupies a silicon area of 1560 μm2 only. Maximum clock frequency from circuit simulation of extracted netlist is 768 MHz under typical, and 463 MHz under worst case technology and application corner conditions, respectively. Simulated dynamic power dissipation is 0.24 uW MHz−1 at 0.9 V; static power is 38 uW in slow corner, 65 uW in typical corner and 518 uW in fast corner, respectively. The latter can be reduced by 43% in a 40-nm CMOS technology using 0.5 V reverse-backbias. These features are compared with the results from different design styles as well as with an implementation in 28-nm CMOS technology. It is interesting that in the latter case area scales as expected, but worst case performance and energy do not scale well anymore.

Optimizing Layout and Amount of Eco-Industrial Demonstration Parks in Jilin Province, China

A great number of Eco-industrial demonstration parks (EIDPs) have been built across China in order to set examples for the full implementation of circular economy and eco-industry. However, a series of problems appear, such as confusing definitions on the two concepts of Eco-industrial parks (EIPs) and EIDPs, disorderly macro layout of EIDPs, lacking a regional network system of EIDPs, etc.. The article holds that EIDPs, besides the basic characteristics of EIPs, should highlight the exemplary role. The location and amount of EIDPs in those regions should be decided through macro layout and amount optimization of EIDPs. In light of this view, a case study in Jinlin Province is applied. The net of EIDPS can set examples for the construction of EIPs across the province, and also avoid redundant construction as well as cut the cost of demonstration.

Product-term-based synthesizable embedded programmable logic cores

As integrated circuits become increasingly complex, the ability to make post-fabrication changes will become more important and attractive. This capability can be realized by using programmable logic cores. Currently, such cores are available from vendors in the form of "hard" macro layouts. Previous work has suggested an alternative approach: vendors supply a synthesizable version of their programmable logic core and the integrated circuit designer synthesizes the programmable logic fabric using standard cells. Although this technique suffers increased delay, area, and power, the task of integrating such cores is far easier than the task of integrating "hard" cores into an ASIC or system-on-chip (SoC). When implementing a small amount of logic, this ease of use may be more important than the increased overhead. This paper presents a new family of architectures for these "synthesizable" cores; unlike previous architectures, which were based on lookup-tables (LUTs), the new family of architectures is based on a collection of product-term arrays. Compared to LUT-based architectures, the new architectures result in density improvements of 35% and speed improvements of 72% on standard benchmark circuits. The improvement is due to the inherent efficiency of product-term-based designs for small logic circuits. In addition, we describe novel ways of enhancing synthesizable architectures to support sequential logic. We show that directly embedding flip-flops as is done in stand-alone programmable cores will not suffice. Consequently, we present two novel architectures employing our solution and optimize and compare them. Finally, we describe a proof-of-concept layout employing one of our proposed architectures.

Strategic facility planning (SFP)

Outlines the evolution of facilities design to the point where it is capable of supporting an organisation’s strategic content. Explains the key principles of strategic facility planning (SFP) and details the key stages of the design process. Outlines seven steps including elements such as determining space requirements and generating macro layouts. Concludes that SFP can provide the process to turn a facility into a facilitator of competitive advantage and customer perceived added value.

A module generator based on the PQ-tree algorithm

GRAPES, a system for module generation that produces faster and denser layout than conventional CAD tools, is described. The layout style produced by GRAPES resembles standard cell layout (vertical polysilicon wires crossing horizontal diffusion stripes) or sea-of-gates macro layout. Contrary to standard cells or macros, the complexity of the individual cells is not limited by any library, cells can be stretched, feedthroughs can run across them, and the transistors can be permuted and sized individually. Cells and rows are produced at the same time in a top-down procedure. A novel algorithm based on the PQ-tree algorithm orders the individual transistor gates in each row such the several rows abut, with no routing channels between the rows. The most critical nets can usually be connected by abutment, even when they connect several cells in different rows. In a comparison with a commercial standard-cell tool, GRAPES produced layout that is about two times smaller and has up to six times shorter total wire length. >