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Full-Text Articles in Engineering
Lachesis: A Job Scheduler For The Cray T3e, Allen B. Downey
Lachesis: A Job Scheduler For The Cray T3e, Allen B. Downey
Allen B. Downey
This paper presents the design and implementation of Lachesis, a job scheduler for the Cray T3E. Lachesis was developed at the San Diego Supercomputer Center (SDSC) in an attempt to correct some problems with the scheduling system Cray provides with the T3E.
Analysis Of Segmentation Algorithms For Pavement Distress Images, Allen Downey, Haris N. Koutsopoulos, Ibrahim El Sanhouri
Analysis Of Segmentation Algorithms For Pavement Distress Images, Allen Downey, Haris N. Koutsopoulos, Ibrahim El Sanhouri
Allen B. Downey
Collection and analysis of pavement distress data is an important component of any pavement‐management system. Various systems are currently under development that automate this process. They consist of appropriate hardware for the acquisition of pavement distress images and, in some cases, software for the analysis of the collected data. An important step in the automatic interpretation of images is segmentation, the process of extracting the objects of interest (distresses) from the background. We examine algorithms for segmenting pavement images and evaluate their effectiveness in separating the distresses from the background. The methods examined include the Otsu method, Kittler's method, a …
Primitive-Based Classification Of Pavement Cracking Images, Allen Downey
Primitive-Based Classification Of Pavement Cracking Images, Allen Downey
Allen B. Downey
Collection and analysis of pavement distress data are receiving attention for their potential to improve the quality of information on pavement condition. We present an approach for the automated classificaton of asphalt pavement distresses recorded on video or photographic film. Based on a model that describes the statistical properties of pavement images, we develop algorithms for image enhancement, segmentation, and distress classification. Image enhancement is based on subtraction of an “average” background: segmentation assigns one of four possible values to pixels based on their likelihood of belonging to the object. The classification approach proceeds in two steps: in the first …