同源高速宏观地质条件对勘察的指导意义

对同源高速公路地貌景观进行了分析,并针对不同地质条件下的工程地质特征进行了工作量布置前的探讨,综合研究后进行了勘察工作,合理指导了勘察与工程建设,对同类工程具有重要的指导意义。     

The Hinterland Urbanised?

What defines the urban? And can the non-urban necessarily always be classified as rural? Neil Brenner , Director of the Urban Theory Lab at Harvard University Graduate School of Design, reflects on the lack of an overarching theory to describe these realms, and argues that what we call the countryside or the hinterland has become key to the process of capitalist urbanisation.     

国外传统农业水适应经验及水适应景观

古代人类在长期水资源管理及与各种水灾害斗争过程中,积累了朴素的具有生态价值的农业生产经验,表现在造田方式、作物类型、水资源管理等方面的适应性景观。研究表明,水适应景观内容和形式受气候干湿类型、地形特征等因素影响。当前,传统农业水适应景观研究已从传统的水利工程设施要素研究转向综合研究,探讨水景观的复杂结构和复合功能。现代水利技术背景下,如何借鉴传统水适应景观经验,探讨新的环境条件下水适应的途径和方法,是值得深入研究的方向。在水适应景观概念的框架下,对不同气候类型、不同地形特点下农业水景观的内容、形式及区域差异的研究,也是值得国内学者借鉴的研究方向。     

城市居住小区景观设计探讨

针对提高居住小区环境设计水平的迫切要求,初步细化了景观设计的范围,并对景观设计的多元统一,规模与亲和,观赏与实用,功能与效果,空间利用与绿化等方面进行探讨,以丰富设计思想。     

Scaling of program functionality

The distribution of fitness values (landscapes) of programs tends to a limit as the programs get bigger. We use Markov chain convergence theorems to give general upper bounds on the length of programs needed for convergence. How big programs need to be to approach the limit depends on the type of the computer they run on. We give bounds (exponential in N, N log N and smaller) for five computer models: any, average or amorphous or random, cyclic, bit flip and four functions (AND, NAND, OR and NOR). Programs can be treated as lookup tables which map between their inputs and their outputs. Using this we prove similar convergence results for the distribution of functions implemented by linear computer programs. We show most functions are constants and the remainder are mostly parsimonious. The effect of ad-hoc rules on genetic programming (GP) are described and new heuristics are proposed. We give bounds on how long programs need to be before the distribution of their functionality is close to its limiting distribution, both in general and for average computers. The computational importance of destroying information is discussed with respect to reversible and quantum computers. Mutation randomizes a genetic algorithm population in generations. Results for average computers and a model like genetic programming are confirmed experimentally.     

Planning and designing for the multiple use role of habitats in urban/suburban landscapes in the Great Basin

Most researchers agree that preserving, creating, and restoring urban wildlife habitats has to be an interdisciplinary undertaking if it is to succeed. Ecologists and wildlife biologists must be key participants. The culturally modified context of most urban habitats suggests that landscape architects also have a primary role to play.Open space in the urban/suburban environment is a scarce and valuable resource. Private and public sector pressure to convert these spaces to commercial or intensive recreational uses are immediate and intense. Presenting arguments to preserve or restore urban open space solely as habitat for wildlife is seldom successful. Decision makers are more likely to support urban wildlife habitat programs if other uses are also accommodated.There is a growing body of research data that suggests that wildlife are being adversely impacted by multiple uses of urban habitats. The challenge for planners and designers is to minimize adverse impacts and capitalize on those attributes of other uses that enhance habitat value. Planning for the temporal as well as spatial dimensions of site uses is required if the needs of wildlife are to be met.The paper presents three general areas in which landscape architects have traditionally contributed to an interdisciplinary approach to urban wildlife habitat planning: contextual perspective, problem solving process, and design/technical execution.Reflecting back on his past 10 years of experience as a landscape architect planning urban wildlife habitats, the author presents several case study projects in which: (A) accommodation of multiple use objectives, including wildlife habitat, was required; (B) interdisciplinary teams participated in the planning and design process; (C) key principles from the fields of landscape ecology, conservation biology and wildlife biology were applied to facility and activity location, habitat configuration, and management.Plans of completed projects are used to illustrate how habitat values were preserved or enhanced and multiple uses accommodated in public open spaces. The paper concludes with a brief summary of keys to success common to each project.     

Collective foraging in heterogeneous landscapes

Animals foraging alone are hypothesized to optimize the encounter rates with resources through Lévy walks. However, the issue of how the interactions between multiple foragers influence their search efficiency is still not completely understood. To address this, we consider a model to study the optimal strategy for a group of foragers searching for targets distributed heterogeneously. In our model, foragers move on a square lattice containing immobile but regenerative targets. At any instant, a forager is able to detect only those targets that happen to be in the same site. However, we allow the foragers to have information about the state of other foragers. A forager who has not detected any target walks towards the nearest location, where another forager has detected a target, with a probability exp(−αd), where d is the distance between the foragers and α is a parameter characterizing the propensity of the foragers to aggregate. The model reveals that neither overcrowding (α → 0) nor independent searching (α → ∞) is beneficial for the foragers. For a patchy distribution of targets, the efficiency is maximum for intermediate values of α. In addition, in the limit α → 0, the length of the walks can become scale-free.