Zipf’s and Gibrat’s laws for migrations

This paper analyses the evolution of the size distribution of the stock of immigrants in the period 1960–2000. In particular, we are interested in testing the validity of two empirical regularities: Zipf’s law, which postulates that the product between the rank and size of a population is constant; and Gibrat’s law, according to which the growth rate of a variable is independent of its initial size. We use parametric and nonparametric methods and apply them to absolute (stock of immigrants) and relative (migration density, defined as the quotient between the stock of immigrants of a country and its total population) measurements. We find that both the stock of immigrants and migration density follow similar size distributions to those of cities and of countries. Contrary to what traditional migrations models predict, growth in the stock of immigrants is independent of the initial stock. Moreover, the growth of migration density shows a divergent behaviour, which could be explained by the lower birth rates of host countries and the reduction in the cost of emigration produced by the presence of a previous stock of immigrants in the country.     

Laura’s Bakery

项目用途:概念店项目业主:Laura’s Bakery项目地点:丹麦哥本哈根项目时间:2011年Project:Concept storeClient:Laura’s Bakery Location:Copenhagen,DKYear:2011材料、食品、室内设计、品牌精神的整体融合是我们设计追求的最高目标。您在这里看到的不仅仅是单独的食品,单独的饰品,单独的空间,您在这里看到的是一个整体的品牌解决方案。     

The ‘People’s City’

The mid-20th-century communist ideal was for cities that were ‘of the people, by the people and for the people’. Wang Jun , an editor at Outlook Weekly magazine and author of a best-selling book on the planning of Beijing, describes how the ambition to accommodate public life in urban space is a relatively modern phenomenon that goes against the grain of a long tradition of landownership in China. Given this background, can the original notion of the ‘People's City’ ultimately survive the current wave of property privatisation? Copyright © 2008 John Wiley & Sons, Ltd.     

On America’s Baby Boom Generation and It’s Social Problems

Baby boom generation is the larger than expected generation in U.S born shortly after World War II. This post- World War II phenomenon upsets the phenomenon which had been a century-long decline in the...     

King’s Mill医院

这个占地21ha的基址在二战期间是一家美国公共医院．在20世纪60年代经历了大规模的无序发展。在开发之前．在这家医院里穿行是一件十分困难的事情．因为相关的医疗服务散落在建筑的各处。     

Consideration of daylight’s colour

The aim of the study is to underline the contribution of colour in daylighting projects as an objective parameter of visual performance and pleasantness.Window technology offers ways to use daylight in buildings. Glazing, shading systems and indoor materials modify its aspect by offering a large variation of its colour. However, colour of daylight changes greatly according to climate, spatially and temporally.Variation of the colour of daylight is illustrated as well as an example of the resulting change of surface colours with or without a type glazing. Then, a method to predict directional colour of skylight is suggested with the intention to apply it in daylighting calculations.     

Good’s综合征研究现状

1954年R.A.Good首次报道了1例患有胸腺瘤及低丙种球蛋白血症的成年患者,2年后又对这类患者的免疫反应进行临床及实验研究,发现患者有免疫功能缺陷,之后学者将这类患者称之为Good’s综合征。90年代后研究者发现该类患者有B淋巴细胞产生分化障碍,T淋巴细胞功能低下,属于原发性免疫缺陷病。     

Something’s Afoot经典地面材料

1．Kyle Bunting出品的“Mirage”定制的蓝色、铂灰色牛皮地毯。2．Tai Ping Carpets出品的方块地毯。3．J＋J／Invision出品的“Pulp”方块地毯为尼龙材料．经着色解决方案设计制作而成。     

Steven Holl’s NYU Philosophy

The New York University Department of Philosophy, by Steven Holl Architects, combines crisply detailed, rigidly rectangular, black and white elements with odd angles, holey walls and fluctuating rainbows inside a soft, curvaceous old masonry building with Romanesque details. Even though the architect is working on enormous mixed-use projects all over the world now, he took a special interest in creating new facilities for the philosophers close to home despite a constricted site and modest budget. Jayne Merkel describes the striking and rather mysterious new spaces in a small-floorplate, six-storey Victorian-era warehouse in Greenwich Village. Copyright © 2008 John Wiley & Sons, Ltd.     

Africa’s Urban Food Deserts

Since the mid-1990s, the concept of the ‘urban food desert’ has been extensively applied to deprived neighbourhoods in European and North American cities. Food deserts are usually characterised as economically-disadvantaged areas where there is relatively poor access to healthy and affordable food because of the absence of modern retail outlets (such as supermarkets). This idea has not been applied in any systematic way to cities of the Global South and African cities in particular. Yet African cities contain many poor neighbourhoods whose residents are far more food insecure and malnourished than their counterparts in the North. This paper reviews some of the challenges and difficulties of conceiving of highly food insecure areas of African cities as conventional food deserts. At the same time, it argues that the concept, appropriately reformulated to fit African realities of rapid urbanisation and multiple food procurement systems, is a useful analytical tool for African urban researchers and policy-makers. Although supermarkets are becoming an important element of the food environment in African cities, a simple focus on modern retail does not adequately capture complexity of the African food desert. In the African context, the food deserts concept requires a much more sophisticated understanding of over-lapping market and non-market food sources, of the nature and dynamism of the informal food economy, of the inter-household differences that lead to different experiences of food insecurity and of the Africa-specific conditions that lead to compromised diets, undernutrition and social exclusion. The papers in this special issue explore these different aspects of African food deserts defined as poor, often informal, urban neighbourhoods characterised by high food insecurity and low dietary diversity, with multiple market and non-market food sources but variable household access to food.