Williams Index Agreement
The total of MVC`s potential compensatory payments due during the term of the Williams agreements “could reach $895 million on an und discounted basis.” For many medical issues, as mentioned earlier, ghost studies are considered insufficient for validation and manual traceability is simply not available. In the work presented here, we focus on the automatic classification of the brain into four main tissue classes: gray matter (GM), white matter (WM), cerebrospinal fluid (CSF) and background (BG). For this specific problem, manual tracking of all the data, a total of forty cases, is simply impossible. Nevertheless, if you were to start a new neuroimaging study, you would certainly like to evaluate automatic classifiers on the entire population. We must therefore turn to methods that measure performance in situations where no fundamental truth is available. A fairly intuitive approach is to carry out such an assessment on the basis of mutual agreement. That is, if nine out of ten algorithms classify voxel x in subject i as white matter, then it is said that there is a 90% chance that this voxel is really white matter. This simple technique is interesting but limited because all algorithms have the same vocal power and situations can occur where a voxel can have the same probability of being divided into different classes of tissues. Nevertheless, this notion of common agreement is useful and can be directly quantified by measures such as the Williams index (Chalana and Kim, 1997; Klingensmith et al., 2000; Martin-Fernandez et al., 2005). A reference can also be created based on the majority of the segmentation votes. The benchmark can then be used as a field truth for other performance metrics.
A more sophisticated technique is that developed by Warfield et al. (2004), which simultaneously creates a reference standard and performance parameters through an expectation maximization framework. In the Haynesville Agreement, Chesapeake plans to enter into a long-term gas supply commitment for the Williams Transcontinental Gas Pipeline, also known as Transco. The agreement would require chesapeake to supply at least 100,000 Dth/d and up to 150,000 Dth/d from its Marcellus shale assets on the Transco Regional Energy Access pipeline currently under development. On Jan. 8, Williams took two steps that accelerated Southland`s “need to seek Chapter 11 discharge,” he said. First, Williams sent Southland a request for adequate security of MVC payments and demanded a cash payment of $6.9 million within 48 hours. A short-term deal was reached and Williams received $1.7 million, with the additional $4 million scraping last Saturday (Jan.
25). Section 3 describes our experimental setup: what data set is used, what algorithms are tested, and what types of tests are performed. This section begins with an experiment where absolutely no basic truth is available and only a common agreement is used. We then validate our approach by creating gold standards based on human traces of a small subset of data to validate whether a common match is really a meaningful approach. We analyze our results in Section 4 and discuss feasibility, accuracy, robustness, scalability, and the importance of evaluating algorithms to classify brain tissue only based on their common agreement in Section 5. Section 6 concludes the document summarising the results obtained. With the similarities defined in section 2.1, one can examine the Williams index statistics for each algorithm, for each label, for all subjects. .