Change point detection

Meerbach E., Schiitte, C. Sequential change point detection in molecular dynamics trajectories. J. Multivariate Anal. Submitted for publication. 

Change Point Detection for Quality Monitoring of Chemical Processes... 

Change Point Detection of EEG Signals Based on Particle Swarm Optimization... 

Keywords— Particle Swarm Optimization, EEG, sinusoidal, change point detection, non-stationary. 

It is certainly clear that a coulometric titration, like any other type of titration, needs an end-point detection system in principle any detection method that chemically fits in can be used, be it electrometric, colorimetric, photoabsorptionmetric, etc. for instance, in a few cases the colour change of the reagent generated (e.g., I2) may be observed visually, or after the addition of a redox, metal or pH indicator the titration end-point can be detected photoabsorptiometrically by means of a light source and photocell combination. Concerning the aforementioned coulometric titration of Fe(II), it is... 

The basic requirements for the CBMS II are to reliably detect and identify with sufficient sensitivity and selectivity both CWA and BWA in point detection and reconnaissance missions, in order to be deployable in wheeled reconnaissance vehicles and be operable by nontechnical personnel wearing, at the extreme, MOPP IV protective gear. Contrary to the usual practice for a military detector system, the CBMS II does not have its own requirements document. Instead, the requirements and specifications for the CBMS II are based on the detector requirements of the host platforms in which it will be deployed. These requirements are described in terms of performance, as opposed to the usual practice of being enumerated in volumes of detailed specifications. As is usual for a complex multiyear program, the requirements changed over the course of the CBMS II program as the requirements for the host platforms evolved. 

A prerequisite for a precise and accurate titration is the reproducible identification of an end point which either coincides with the stoichiometric point of the reaction or bears a fixed and measurable relation to it. An end point may be located either by monitoring a property of the titrand which is removed when the stoichiometric point is passed, or a property which can be readily observed when a small excess of the titrant has been added. The most common processes observed in end-point detection are change of colour change of electrical cell potential change of electrical conductivity precipitation or flocculation. (Electrochemical methods are discussed in Chapter 6 precipitation indicators find only limited use.)... 

The output trace from the laser end-point detection system for a typical resist development cycle is depicted in Figure 9. The temporal distance between maxima can be related to a change in resist thickness through Equation 11... 

This expression is independent of the film thickness. Thus, when one considers reflective monitoring of metal film etching, only at the interface between film and substrate will a change in reflectivity be observed due to the change in refractive index. Although this is extremely useful for end point detection one still must apply films of known thickness for cases in which etch rate information is desired. 

Conformational changes are detected in the near-UV CD spectrum if they affect the conformation or environment of side chain aromatic residues. On the other hand, they affect the far-UV CD spectrum only if substantial changes in secondary structure content occur. Larger amounts of proteins are required for near-UV CD than for far-UV CD spectroscopy given that absorptions in the former are at least an order of magnitude smaller. Because the pH-dependent conformational changes in BmPBP involve aromatic side chains, possibly tryptophan, they were also mirrored in fluorescence spectroscopy. This is fortuitous given that fluorescence requires smaller amounts of protein, which can consequently be obtained from natural sources. It is important to point out that for such experiments, however, proteins must be scrupulously pure and devoid of other chromophores. 

The dissolution rates, R, of the resist films in the developer were measured using a laser end-point detection system. (O Figure 6 shows the output of the device for an ideal case. The change in film thickness between maxima (or minima) At is given by... 

WTW and RTR control of thickness are improved by the use of end-point detection systems and advanced process control. End-point detection, whether mechanical or optical, monitor the state of the wafer surface (film thickness, reflectivity, etc.) or of the entire polishing system (friction, slurry by products, etc.) in an attempt to predict when the desired amount of material has been removed (i.e., the end of process). End-point detection is most successful in processes where a change in the films on the wafer surface leads to an abrupt change in the optical or mechanical properties of the wafer surface. For example, copper CMP end point is easy to detect by optical means due to the large difference in reflectivity of the copper film compared to the barrier films. In contrast, end-point detection for small amounts of ILD removal is difficult due to the lack of change in the wafer surface or the wafer-pad interface. 

The use of metal-ion indicators to indicate the end-point of complexometric titrations is based on a specific colour change. Some individuals may find it difficult to detect a particular colour change (e.g. those with colour blindness). Alternative approaches for end-point detection are available based on a colorimeter/spectrophotometer (devices for measuring colour, see Chapter 26) or electrochemical detection (see Chapter 34). 

---