80 research outputs found
Optimum mask and source patterns to print a given shape
Proceedings of S P I E - the International Society for OpticalNew degrees of freedom can be optimized in mask shapes when the source is also adjustable, because required image symmetries can be provided by the source rather than the collected wavefront. The optimized mask will often consist of novel sets of shapes that are quite different in layout from the target IC patterns. This implies that the optimization algorithm should have good global convergence properties, since the target patterns may not be a suitable starting solution. We have eveloped an algorithm that can optimize mask and source without using a starting design. Examples are shown where the process window obtained is between 2 and 6 times larger than that achieved with standard RET methods. The optimized masks require phase shift, but no trim mask is used. Thus far we have only optimized 2D patterns over small fields (periodicities of 1im or less). We also discuss mask optimization with fixed source, source optimization with fixed mask, and the re-targeting of designs in different mask regions to provide a common exposure level.published_or_final_versio
Optimum mask and source patterns to print a given shape
New degrees of freedom can be optimized in mask shapes when the source is also adjustable, because required image symmetries can be provided by the source rather than the collected wave front. The optimized mask will often consist of novel sets of shapes that are quite different in layout from the target integrated circuit patterns. This implies that the optimization algorithm should have good global convergence properties, since the target patterns may not be a suitable starting solution.
We have developed an algorithm that can optimize mask and source without using a starting design. Examples are shown where the process window obtained is between two and six times larger than that achieved with standard reticle enhancement techniques (RET). The optimized masks require phase shift, but no trim mask is used. Thus far we can only optimize two-dimensional patterns over small fields (periodicities of ;1 mm or less), though patterns in two separate fields can be
jointly optimized for maximum common window under a single source. We also discuss mask optimization with fixed source, source optimization with fixed mask, and the retargeting of designs in different mask regions to provide a common exposure level. © 2002 Society of Photo-Optical Instrumentation Engineers.published_or_final_versio
Effects of compression clothing on speed–power performance of elite Paralympic sprinters: a pilot study
Query Large Scale Microarray Compendium Datasets Using a Model-Based Bayesian Approach with Variable Selection
In microarray gene expression data analysis, it is often of interest to identify genes that share similar expression profiles with a particular gene such as a key regulatory protein. Multiple studies have been conducted using various correlation measures to identify co-expressed genes. While working well for small datasets, the heterogeneity introduced from increased sample size inevitably reduces the sensitivity and specificity of these approaches. This is because most co-expression relationships do not extend to all experimental conditions. With the rapid increase in the size of microarray datasets, identifying functionally related genes from large and diverse microarray gene expression datasets is a key challenge. We develop a model-based gene expression query algorithm built under the Bayesian model selection framework. It is capable of detecting co-expression profiles under a subset of samples/experimental conditions. In addition, it allows linearly transformed expression patterns to be recognized and is robust against sporadic outliers in the data. Both features are critically important for increasing the power of identifying co-expressed genes in large scale gene expression datasets. Our simulation studies suggest that this method outperforms existing correlation coefficients or mutual information-based query tools. When we apply this new method to the Escherichia coli microarray compendium data, it identifies a majority of known regulons as well as novel potential target genes of numerous key transcription factors
Colour photographs for screening in neovascular age-related macular degeneration: are they necessary?
AIMS: To investigate whether optical coherence tomography (OCT) with associated infra-red images provide enough information to determine treatment decisions in the management of neovascular age-related macular degeneration (nAMD), or whether retinal colour photography is also necessary. METHODS: In all, 87 OCT scans of 82 eyes with nAMD undergoing monitoring post ranibizumab treatment were taken using the Zeiss Stratus (Carl Zeiss Meditec, Jena, Germany; n=87) together with their corresponding infra-red images. Fundus colour photographs were also taken. These images were reviewed by an experienced assessor, and a ranibizumab treatment decision was made during a multidisciplinary team retinal image review meeting. RESULTS: In all, 30 OCT scans (34.5%) showed intraretinal or subretinal oedema. A total of 24 colour photographs (19.5%) demonstrated retinal haemorrhage. Corresponding OCT infra-red images gave poor sensitivity in detecting haemorrhages (0.176). In 16.7% of decisions to treat, haemorrhage alone was the deciding factor. Signs of disease activity seen only on colour photography were the deciding factor in clinical decisions for 8% of scans assessed. CONCLUSIONS: The presence or increase of intra-retinal oedema is an important sign of activity triggering ranibizumab retreatment, but some eyes show signs of retinal haemorrhage without coexisting oedema. These haemorrhages are often only seen on either colour imaging or fundoscopy and are unclear or invisible on OCT scans and infra-red images. Therefore, although retinal colour photography creates additional expense, it is indispensable for making informed retreatment decisions, if patients are monitored using retinal imaging alone
Alteration of Ingestive Behavior and Plasma Metabolites by Estrogen in Ovariectomized Goats.
Production of matrix metalloproteinases and tissue inhibitor of metalloproteinases-1 by human brain tumors
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