CHAMP: Creating Heuristics via Many Parameters for online bin packing

The online bin packing problem is a well-known bin packing variant which requires immediate decisions to be made for the placement of a lengthy sequence of arriving items of various sizes one at a time into fixed capacity bins without any overflow. The overall goal is maximising the average bin fullness. We investigate a ‘policy matrix’ representation which assigns a score for each decision option independently and the option with the highest value is chosen for one dimensional online bin packing. A policy matrix might also be considered as a heuristic with many parameters, where each parameter value is a score. We hence investigate a framework which can be used for creating heuristics via many parameters. The proposed framework combines a Genetic Algorithm optimiser, which searches the space of heuristics in policy matrix form, and an online bin packing simulator, which acts as the evaluation function. The empirical results indicate the success of the proposed approach, providing the best solutions for almost all item sequence generators used during the experiments. We also present a novel fitness landscape analysis on the search space of policies. This study hence gives evidence of the potential for automated discovery by intelligent systems of powerful heuristics for online problems; reducing the need for expensive use of human expertise

Poverty and respectability in early twentieth-century Cape Town

Cape Town's black population of the early twentieth century actively pursued lifestyles that might be described as respectable. But respectability was expensive, and poverty —characterised by poor housing, ill health and shortened lifespans — stood in the way of some of its most essential elements: cleanliness, sexual restraint, sobriety, and the creation of nuclear and gendered households. Black respectability, therefore, could not simply replicate that of the dominant white bourgeoisie. Most challenging was the development of rampant black criminality, often seen by contemporary observers as the result of the failure of black women to realise respectable households. Even attempts on the part of the state to create respectable citizenries floundered, partly because these initiatives were incompatible with the policies of racial segregation. The state and the dominant bourgeoisie put their faith in the black elite as the standard-bearers of respectability, but the reality was that the respectability of the ‘superior’ class was frequently indistinguishable from those below, a consequence of the fact that the boundary between these classes was highly porous

Dendrimer-Functionalized Shell-crosslinked Iron Oxide Nanoparticles for In-Vivo Magnetic Resonance Imaging of Tumors

No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58645/1/1671_ftp.pd

Dendrimer-Functionalized Iron Oxide Nanoparticles for Specific Targeting and Imaging of Cancer Cells

We demonstrated a unique approach that combines a layer-by-layer (LbL) self-assembly method with dendrimer chemistry to functionalize Fe 3 O 4 nanoparticles (NPs) for specific targeting and imaging of cancer cells. In this approach, positively charged Fe 3 O 4 NPs (8.4 nm in diameter) synthesized by controlled co-precipitation of Fe II and Fe III ions were modified with a bilayer composed of polystyrene sulfonate sodium salt and folic acid (FA)- and fluorescein isothiocyanate (FI)-functionalized poly(amidoamine) dendrimers of generation 5 (G5.NH 2 -FI-FA) through electrostatic LbL assembly, followed by an acetylation reaction to neutralize the remaining surface amine groups of G5 dendrimers. Combined flow cytometry, confocal microscopy, transmission electron microscopy, and magnetic resonance imaging studies show that Fe 3 O 4 /PSS/G5.NHAc-FI-FA NPs can specifically target cancer cells overexpressing FA receptors. The present approach to functionalizing Fe 3 O 4 NPs opens a new avenue to fabricating various NPs for numerous biological sensing and therapeutic applications.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57409/1/3043_ftp.pd

In Situ Bioremediation through Mulching of Soil Polluted by a Copper–Nickel Smelter

Received for publication September 8, 2000. Bioremediation of a heavy metal–polluted soil was investigated in a 3-yr field experiment by adding mulch to a polluted forest floor. The mulch consisted of a mixture of compost and woodchips. The remediation treatment decreased the toxicity of the soil solution to bacteria as determined by the [3H]-thymidine incorporation technique, that is, by measuring the growth rate of soil bacteria extracted from unpolluted humus after exposing them to soil solution containing heavy metals from the experimental plots. Canonical correlation analysis was performed in order to identify the chemical and microbiological changes in the soil. The pH of the mulched organic layer increased by one unit. The concentration of complexed Cu increased and that of free Cu2+ decreased in the soil solution from the mulch treatment. According to basal respiration and litter decomposition, microbial activity increased during the 3 yr following the remediation treatment. The [3H]-thymidine incorporation technique was also used to study the growth rate and tolerance of bacteria to Cu. The bacterial growth rate increased and the Cu tolerance decreased on the treated plots. The structure of the microbial community, as determined by phospholipid fatty acid (PLFA) analysis, remained unchanged. The results indicate that remediation of the polluted soil had occurred, and that adding a mulch to the forest floor is a suitable method for remediating heavy metal–polluted soil