Minimizing sum of completion times on a single machine with sequence-dependent family setup times

This paper presents a branch-and-bound (B&B) algorithm for minimizing the sum of completion times in a singlemachine scheduling setting with sequence-dependent family setup times. The main feature of the B&B algorithm is a new lower bounding scheme that is based on a networkformulation of the problem. With extensive computational tests, we demonstrate that the B&B algorithm can solve problems with up to 60 jobs and 12 families, where setup and processing times are uniformly distributed in various combinations of the [1,50] and [1,100] ranges

Consumer exposure to biocides - identification of relevant sources and evaluation of possible health effects

<p>Abstract</p> <p>Background</p> <p>Products containing biocides are used for a variety of purposes in the home environment. To assess potential health risks, data on products containing biocides were gathered by means of a market survey, exposures were estimated using a worst case scenario approach (screening), the hazard of the active components were evaluated, and a preliminary risk assessment was conducted.</p> <p>Methods</p> <p>Information on biocide-containing products was collected by on-site research, by an internet inquiry as well as research into databases and lists of active substances. Twenty active substances were selected for detailed investigation. The products containing these substances were subsequently classified by range of application; typical concentrations were derived. Potential exposures were then estimated using a worst case scenario approach according to the European Commission's Technical Guidance Document on Risk Assessment. Relevant combinations of scenarios and active substances were identified. The toxicological data for these substances were compiled in substance dossiers. For estimating risks, the margins of exposure (MOEs) were determined.</p> <p>Results</p> <p>Numerous consumer products were found to contain biocides. However, it appeared that only a limited number of biocidal active substances or groups of biocidal active substances were being used. The lowest MOEs for dermal exposure or exposure by inhalation were obtained for the following scenarios and biocides: indoor pest control using sprays, stickers or evaporators (chlorpyrifos, dichlorvos) and spraying of disinfectants as well as cleaning of surfaces with concentrates (hydrogen peroxide, formaldehyde, glutardialdehyde). The risk from aggregate exposure to individual biocides via different exposure scenarios was higher than the highest single exposure on average by a factor of three. From the 20 biocides assessed 10 had skin-sensitizing properties. The biocides isothiazolinone (mixture of 5-chloro-2-methyl-2H-isothiazolin-3-one and 2-methyl-2H-isothiazolin-3-one, CMI/MI), glutardialdehyde, formaldehyde and chloroacetamide may be present in household products in concentrations which have induced sensitization in experimental studies.</p> <p>Conclusions</p> <p>Exposure to biocides from household products may contribute to induction of sensitization in the population. The use of biocides in consumer products should be carefully evaluated. Detailed risk assessments will become available within the framework of the EU Biocides Directive.</p

Chip assignment algorithms for dynamic wafer design in semiconductor manufacturing

Chip assignment algorithms for dynamic wafer design in semiconductor manufacturin

Second eyes to develop neovascular age-related macular degeneration have fewer symptoms and better one-year visual outcomes

Abstract Background This study compares the visual and anatomical outcomes for the eyes of patients who developed sequential neovascular age-related macular degeneration (nAMD), both at the time of diagnosis and at one year after treatment. Methods The study comprised a retrospective case series of 52 patients whose eyes were diagnosed sequentially with nAMD. All eyes were treated with three monthly loading doses of anti-vascular endothelial growth factor agents, followed by further intravitreal injections, as required. Baseline characteristics and outcomes at one year after diagnosis and initial treatment were compared between first and second eyes and included visual acuity (VA), central macular thickness (CMT), and pigment epithelial detachment (PED) height on optical coherence tomography (OCT) imaging. Results VA at diagnosis was better for second eyes compared with first eyes to develop nAMD (logMAR 0.68 ± 0.51 versus logMAR 0.41 ± 0.34, P = 0.002) and remained so at one year (logMAR 0.61 ± 0.60 versus logMAR 0.42 ± 0.37, P = 0.041). Similarly, PED height at diagnosis was higher in first eyes (225 ± 176 μm versus 155 ± 144 μm, P = 0.003) and also at one year (188 ± 137 μm versus 140 ± 112 μm, P = 0.019). Whereas most patients reported symptoms at first eye diagnosis (71.2%), half as many second eyes were symptomatic (28.8%, P < 0.001). Significantly more symptomatic first eyes experienced visual distortions (32.4% versus 13.3%) or scotomas (29.4% versus 6.7%), compared with a less specific visual complaint of blurry vision (38.2% versus 80.0%, P = 0.006). Conclusions Compared with first eyes to develop nAMD, second eyes tended to have better vision, smaller PED heights, and fewer symptoms likely because monitoring permitted earlier diagnosis