Hampshire College

About: Hampshire College is a education organization based out in Amherst Center, Massachusetts, United States. It is known for research contribution in the topics: Genetic programming & Population. The organization has 461 authors who have published 998 publications receiving 40827 citations.

Size control via size fair genetic operators in the PushGP genetic programming system

Abstract: The growth of program size during evolution (code "bloat") is a well-documented and well-studied problem in genetic programming. This paper examines the use of "size fair" genetic operators to combat code bloat in the PushGP genetic programming system. Size fair operators are compared to naive operators and to operators that use "node selection" as described by Koza. The effects of the operator choices are assessed in runs on symbolic regression, parity and multiplexor problems (2,700 runs in total). The results show that the size fair operators control bloat well while producing unusually parsimonious solutions. The computational effort required to find a solution using size fair operators is about equal to, or slightly better than, the effort required using the comparison operators.

Is Environmental Justice Good for White Folks? Industrial Air Toxics Exposure in Urban America

Abstract: Objectives The study examines spatial variation in exposure to toxic air pollution from industrial facilities in urban areas of the United States in relation to the local distribution of the pollution burden. Methods We conducted between- and within-city analysis of geographic microdata from the U.S. Environmental Protection Agency's Risk-Screening Environmental Indicators project and data from the 2000 U.S. Census. Results Average exposure in an urban area is positively correlated with the extent of racial and ethnic disparity in the distribution of the exposure burden. Average exposures also tend to be higher for all population subgroups, including whites, in urban areas with higher minority pollution-exposure discrepancies. Conclusions The correlations could arise from causal linkages in either or both directions: the ability to displace pollution onto minorities may lower the effective cost of pollution for industrial firms; and higher average pollution burdens may induce whites to invest more political capital in efforts to influence firms’ siting decisions. The analysis suggests that improvement in environmental justice could benefit not only minorities but also whites.

Voice of the Leopard: African Secret Societies and Cuba

Abstract: In Voice of the Leopard: African Secret Societies and Cuba, Ivor L. Miller shows how African migrants and their political fraternities played a formative role in the history of Cuba. During the eighteenth and nineteenth centuries, no large kingdoms controlled Nigeria and Cameroon's multilingual Cross River basin. Instead, each settlement had its own lodge of the initiation society called Ekpe, or "leopard," which was the highest indigenous authority. Ekpe lodges ruled local communities while also managing regional and long-distance trade. Cross River Africans, enslaved and forcibly brought to colonial Cuba, reorganized their Ekpe clubs covertly in Havana and Matanzas into a mutual-aid society called Abakua, which became foundational to Cuba's urban life and music. Miller's extensive fieldwork in Cuba and West Africa documents ritual languages and practices that survived the Middle Passage and evolved into a unifying charter for transplanted slaves and their successors. To gain deeper understanding of the material, Miller underwent Ekpe initiation rites in Nigeria after ten years' collaboration with Abakua initiates in Cuba and the United States. He argues that Cuban music, art, and even politics rely on complexities of these African-inspired codes of conduct and leadership. Voice of the Leopard is an unprecedented tracing of an African title-society to its Caribbean incarnation, which has deeply influenced Cuba's creative energy and popular consciousness.