Implementation issues

The optimal pulse separation between two images is influenced by a number of parameters. Two main types of error affect the choice of pulse separation (At), that is, random error and acceleration error. Random error arises from noise during recording of images and subsequent interrogation of the particle images. Acceleration error arises from approximation of Lagrangian motion of tracer particle to local Eulerian velocity based on small particle displacement  

These two kinds of error contradict the selection of pulse separation. The random error contribution can be reduced by increasing At but acceleration error increases as At increases. At some intermediate value of At, the total error should be a minimum. The optimum separation can be derived by considering these two errors as (Boillot and Prasad, 1996) 

In order to evaluate the correlation correctly with a single pass, the correlation function must be small with respect to the displacement correlation peak. This is accomplished when the following requirements are fulfilled  

There should be at least 7-10 particle image pairs in each interrogation spot. 

The in-plane displacement should be limited to 1/4 of the size of the interrogation region. 

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Implementation Issues A critical factor in the successful application of any model-based technique is the availability of a suitaole dynamic model. In typical MPC applications, an empirical model is identified from data acquired during extensive plant tests. The experiments generally consist of a series of bump tests in the manipulated variables. Typically, the manipulated variables are adjusted one at a time and the plant tests require a period of one to three weeks. The step or impulse response coefficients are then calculated using linear-regression techniques such as least-sqiiares methods. However, details concerning the procedures utihzed in the plant tests and subsequent model identification are considered to be proprietary information. The scaling and conditioning of plant data for use in model identification and control calculations can be key factors in the success of the apphcation. 

The practical, implementational issues that arise during the utilization of the data compression techniques, presented in the previous two subsections, are discussed in the following paragraphs. 

Not surprisingly, the essential component of flat-histogram algorithms is the determination of the weights, r/, or the thermodynamic potential, e.g., / or /. There exist a number of techniques for accomplishing this task. The remainder of this section is dedicated to reviewing a small but instructive subset of these methods, the multicanonical, Wang-Landau, and transition-matrix approaches. We subsequently discuss their common and sometimes subtle implementation issues, which become of practical importance in any simulation. 

Airline Passenger Security Screening New Technologies and Implementation Issues , National Research Council, Report NMAB-482-1, 1996. 

The contents of the book are intended to help a newcomer in the field, as well as to provide current information including developing technologies, for those who have practiced process analytical chemistry and PAT for some time. The main spectroscopic tools used for PAT are presented NIR, Raman, UV-Vis and FTIR, including not just the hardware, but many apphcation examples, and implementation issues. As chemometrics is central for use of many of these tools, a comprehensive chapter on this, now revised to more specifically address some issues relevant to PAT is included. In this second edition many of the previous chapters have been updated and revised, and additional chapters covering the important topic of sampling, and the additional techniques of NMR, fluorescence, and acoustic chemometrics are included. 

III. Implementation Issues Mandates, Setting Prices, and Vouchers... 

Our understanding of practical implementation issues is inadequate currently. Such issues encompass (1) a better understanding of how the path for financial incentives translates into actual investments in R D ... 

Although the principle is easy to state and, as we will show, many of the component properties are measurable, one critical implementation issue is the trade-off when the new chemical is better on some but not all metrics. How these different factors will be balanced in the case of mixed results will require careful consideration of the... 

Naturally many practical implementation issues arise, including the need to solve the dynamical equations, at least in the regions of importance sampled by the data. In this regard there is a classical mechanical analogue of the coupled dynamical and integral equations. Exploitation of classical inversion may be important, at least as a first step to define the potential in polyatomic cases. The key point at this time is that the new formulation provides a rigorous foundation to build upon for achieving direct practical inversions of temporal and spectroscopic data. 

NIR spectroscopy was utilized by Aldridge and coworkers86 to determine, in a rapid manner, the polymorphic quality of a solid drug substance. Two computational methods, Mahalonobis distance and soft independent modeling of class analogy (SIMCA) residual variance, were used to distinguish between acceptable and unacceptable samples. The authors not only determined that the Mahalonobis distance classification yielded the best results, they addressed one of the key implementation issues regarding NIR as a PAT tool. 

C.T. Chang and J.W. Chen. Implementation issues concerning the EKF-based fault diagnosis techniques. Chemical Engineering Science, 50(18) 2861—2882, 1995. 

Vitally, policy makers need to consider the implementation of the standard at this early stage, in particular the degree of flexibility in the way it may be expressed and implemented. Chapter 3 deals with implementation issues in detail, but standards can fail to be implemented because these factors were not addressed early enough in the process. 

Except for occasional discussions of the basis set dependence of the results, the numerical implementation issues such as grid integration techniques, electron-density fitting, frozen-cores, pseudopotentials, and linear-scaling techniques, are omitted. 

Next, we must decide how to combine the utility exchanger with the P/P exchanger. This could be done either in a series or parallel arrangement. Physical implementation issues may dictate this choice but it could affect controllability. Finally, we have to decide how to control the utility exchanger for best overall control performance. An example will illustrate these issues. 

For analyses of the CWC, see the issue of Disarrruiment A Periodic Review by the United Nations 16 1 (1993) devoted to the Convention Brad Roberts, ed.. The Chemical Weapons Convention Implementation Issues (Washington, DC CSIS, 1992). 

According to some reports, Libya had decided in principle to join the CWC as early as 2001. It is also noteworthy that Libya had maintained contact with the OPCW and followed its decision-making on implementation issues since the very beginning of the preparatory work in 1993, which is very different from some other Arab countries, such as Egypt or Syria, that approached the CWC primarily in the context of the conflict with Israel. 

Another national implementation issue raised was that a number of States Parties have tended to focus exclusively on specific CWC obligations, and have not developed legislation relevant to the more general requirements of the CWC, such as those in Article I, which embodies the prohibition on chemical weapons. Important in this regard is implementation of the general-purpose definition of chemical weapons, which recognizes that, in addition to the chemicals listed in the CWC Schedules, other toxic chemicals could be used as chemical weapons, either as part... 

Software implementation. The complexity of the integrated optimization problem is exacerbated when implementation issues are considered. A unifying framework is needed that will allow both software and humans involved with various levels of the Process Operations Hierarchy to seamlessly communicate with one another in a decisionmaking process over time. 

The technical work on developing the GHS was completed in 2001. The technical GHS Document (the Purple Book ) gives the classification criteria and the hazard communication elements, as well as examples of labels and classification of chemicals to illustrate how to apply the criteria. The UN Sub-Committee on the Globally Harmonized System (SCEGHS) will maintain update, and promote the technical GHS Document as well as manage implementation issues. More information about the GHS and the GHS Document is available at the Relevant Websites section. 

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