POSSIBLE WORLDS: HENRI LEFEBVRE AND THE RIGHT TO THE CITY

There has been much attention paid recently the idea of the right to the city. This article argues that in order to fully appreciate the power of the idea, we should understand it through a close reading of Henri Lefebvre's body of work on the city and politics. Lefebvre presents a radical vision for a city in which users manage urban space for themselves, beyond the control of both the state and capitalism. However, while it calls for profound change, Lefebvre's vision is also eminently practical; it can very much serve as a guide and inspiration for concrete action to change the city today.     

Evaluation of several classification schemes for mapping forest cover types in Michigan †

Abstract

Landsat MSS data were evaluated for mapping forest cover types in the northern Lower Peninsula of Michigan. The study examined seasonal variations, interpretation procedures and vegetation composition/distribution and their effect on overall classification accuracy and ability to identify individual pine species. Photographic images were used for visual interpretations while digital analysis was performed using a common (ERDAS) microcomputer image processing system. The classification schemes were evaluated using contingency tables and were ranked using the KAPPA statistic. The various classification schemes were ranked differentially according to study site location. Visual interpretation procedures ranked best, or least accurate, depending on the spatial distribution and complexity of the forest cover. Supervised classification techniques were more accurate than unsupervised clustering over all sites and seasons. Maximum likelihood classification of June data was superior to any digital classification technique of February data. The study indicates that classification accuracy is more dependent on the composition and distribution of forests in the northern Lower Peninsula of Michigan than on the selection of a particular classification scheme.     

CONCURRENT ENGINEERING DESIGN FOR ENVIRONMENT

This paper attempts to give a brief overview of the concept of design for environment (DfE) as part of the concurrent engineering philosophy. DfE includes designing for recyclability, reuseability, durability, and maintainability. DfE also promotes the reduction of energy consumption and product emissions as a means of environmental consciousness. As part of this research into DfE, five Hunter Valley–based Australian businesses were used as case studies in an attempt to discover what role DfE plays in local Australian industry.     

X100试验管线钢管的规范和生产

介绍了位于英国诺林伯利亚,钢管直径1 219 mm(48 in),输气压力18 MPa(180 bar),由英国BP公司承建的X100试验管线的建设概况.根据X100试验管线的设计参数制定了相应的钢管规范,设计了X100管线钢管母材、焊缝金属和热影响区的合金成分.按设计的合金成分由住友金属鹿岛钢铁厂生产了钢材、钢板,并...     

SOCIAL INTERACTION IN MIXED‐INCOME DEVELOPMENTS: RELATIONAL EXPECTATIONS AND EMERGING REALITY

ABSTRACT: In many cities, public housing has come to exemplify concentrated urban poverty and the social problems associated with it. One major policy response to addressing these problems is the demolition and redevelopment of public housing complexes as mixed‐income communities. Several theoretical propositions that lie behind this policy are based on assumptions about the ways in which living among higher‐income residents can lead to relationships and interactions that may benefit poor people. Based on in‐depth qualitative research in two mixed‐income developments in Chicago, this paper explores the dynamics of social interaction in an effort to better understand the processes and factors that influence such interaction on the ground, the differential experience of residents from different backgrounds, and the factors that contribute to their decision‐making about and interpretation of social relations with their neighbors. This analysis helps to better interpret the findings of earlier studies and craft more informed expectations about such interactions and their likely effects.     

Optimal adjustment strategies for a process with run-to-run variation and 0–1 quality loss

As short run manufacturing becomes more prevalent, run-to-run components of variation, such as that contributed by set-up error, have greater potential to crucially affect product quality. While efforts should be made to eliminate such between-run variance contributing factors, some will always be present. Here, we assume there is one such factor which we envisage as set-up error that, unless the process is adjusted, remains fixed throughout a run. We develop a single adjustment strategy based on taking a sample of fixed size from the process. If a significant set-up error is indicated, a single compensatory adjustment, equal to the predicted process offset, is executed. The actual procedure depends on process parameters, including adjustment error, run size, and adjustment and sampling costs. The procedure not only specifies the adjustment amount, if any, but the time during the run at which to adjust. The procedure is, optimal among all fixed sample size procedures for the chosen cost function. Besides incorporating adjustment and sampling costs, the cost function is based on a 0-1 loss criterion, where the loss is 0 (1) units per item produced if the process offset caused by set-up error is less than or equal to (greater than) a specified amount. Tables are provided, with examples, illustrating the procedure for representative values of process parameters, costs, and run sizes.     

Time dependent upward frequency shifts in the Orbitron MASER

In our experiments with the pulsed Oribtron MASER, we have noted that there is an upward chirp in frequency even though the anode voltage is decreasing. We have found theoretically that this is a natural consequence of the negative-mass instability and the chirp rate can be predicted from this theory. Experimental data we have obtained is also in good agreement with these predictions.     

FRIENDS AND NEIGHBORS: HOMEOWNERSHIP AND SOCIAL CAPITAL AMONG LOW‐ TO MODERATE‐INCOME FAMILIES

ABSTRACT: This research explores whether homeownership leads to increased individual social capital among low‐ to moderate‐income families. Social capital refers to social resources a person can access through contacts with others in his or her social networks. We theorize that homeownership can motivate interactions with others in one's neighborhood and therefore build social capital. Using a sample of low‐ and moderate‐income homeowners and a matched sample of renters, we collect data on overall social resources and neighborhood‐specific social resources. We find that homeowners have more total social capital resources and more neighborhood social capital resources than renters. Neighborhood group involvement has an indirect effect on social capital, but explains only a small amount of the influence of homeownership. These findings hold when controlling for household‐level and neighborhood‐level sociodemographic variables, as well as when using statistical models that account for endogeneity. Based on this evidence, we conclude that homeownership gives people access to social capital via increased social ties to others. We discuss the implications of this finding for housing policy and suggest new directions for research on social capital.     

Dynamic Analysis of Low-Rise Buildings on Microcomputers

An analytical model for dynamic response analysis of low-rise steel frame buildings on microcomputers is described. The model consists of an assemblage of planar frames with either braced or moment resisting connections. All but the frame lateral degrees of freedom are removed using static condensation prior to assemblage of the overall model. Floor diaphragms are modeled as either flexible or completely rigid in their own planes. Linear elastic behavior is assumed in the model and time-history dynamic analysis is performed using the mode-acceleration method. A FORTRAN computer program was written to implement the model on a microcomputer and a sample analysis of an actual building is presented to illustrate its use. The program was envisioned as a simplified analysis and design tool which could aid a designer in investigating a proposed structure or in rehabilitating an existing one for lateral forces.     

Flexible manufacturing system structural control and the Neighborhood Policy,part 1. Correctness and scalability

IIE Transactions - Structural Control Policies (SCPs) are real-time flexible manufacturing system (FMS) operating policies that guarantee deadlock-free operation. SCPs must be correct and scalable....