Software Implementation

The input to this phase consists of the specifications for the internal design and for the interfaces of the software modules. The outputs are the listings containing the source code and the executable code and the results of unit tests and module interface tests. 

The production of code that can be demonstrated to be a correct implementation of the software specifications is a major issue. The code should be verifiable against these specifications. If verification is made by human inspection, the code should be readable, adequately annotated and understandable. Validated tools should be used to facilitate the code verification process (see Section 10). 

Code cannot nsually be produced correctly in a first version. The requests for changes and the modifications made in implementation should be carefully controlled and coherence between the successive versions that are produced should be maintained. 

For safety systems, the programming language (or the subset which is used) should have a rigorously defined and documented syntax and semantics. 

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The most popular of the SCRF methods is the polarized continuum method (PCM) developed by Tomasi and coworkers. This technique uses a numerical integration over the solute charge density. There are several variations, each of which uses a nonspherical cavity. The generally good results and ability to describe the arbitrary solute make this a widely used method. Flowever, it is sensitive to the choice of a basis set. Some software implementations of this method may fail for more complex molecules. 

Although the traditional point of reference for safety interlock systems is a hard-wired implementation, a programmed implementation is an alternative. The potential for latent defects in software implementation is a definite concern. Another concern is that solid-state components are not guaranteed to fail to the safe state. The former is addressed by extensive testing the latter is addressed by manufacturer-supplied and/or user-supplied diagnostics that are routinely executed by the processor within the safety interlock system. Although issues must be addressed in programmable implementations, the hard-wired implementations are not perfect either. 

Slightly different implementations of the above PLS-NIPALS algorithm exist. They mostly differ in the chosen normalization of w, t or p (here Iwl = 1). This is not an important issue, but it may be a cause of confusion when comparing results from different (software) implementations. That the normalization is of no real importance can be seen as follows. Let us say we choose to multiply the weight... 

Figure 7.11 Horizontal packages slices business, software spec, software implementation.

Some details in the concepts of PLS and the different methods and different software implementations make PLS still a black box or at least a dark gray box to most chemists. Essential facts for the user of PLS can be summarized as follows (Figure 4.24) ... 

Everything in QED is stored in "triples like in the LEAP language. (28) Each triple consists of an index, an attribute, and a value. QED maintains pointer lists to entries that have the same index, attribute, or value so that it can quickly retrieve relations given any combination of I, A, or V. The triples are stored in QED s software implemented virtual memory that is mapped to disk. The internal form of the ALPHA-TO-SC rule is shown in Table IV. 

Following the very brief introduction to the method of lines and differential-algebraic equations, we return to solving the boundary-layer problem for nonreacting flow in a channel (Section 7.4). From the DAE-form discretization illustrated in Fig. 7.4, there are several important things to note. The residual vector F is structured as a two-dimensional matrix (e.g., Fuj represents the residual of the momentum equation at mesh point j). This organizational structure helps with the eventual software implementation. In the Fuj residual note that there are two timelike derivatives, u and p (the prime indicates the timelike z derivative). As anticipated from the earlier discussion, all the boundary conditions are handled as constraints and one is implicit. That is, the Fpj residual does not involve p itself. 

To allow the pharmaceutical manufacturer to ensure the correctness and completeness of the software implementation through traceability to the software design specification... 

Most of these potential sources of error have actually been eliminated, or at least minimized, in commercial analyzers by proper hardware and software implementation, e.g., proper washing and cleansing procedures, signal stability criteria, corrections of the residual potential or simply by declaring limits , i.e., the types of sample, interfering substances, vial types to be avoided, by limiting the number of reports per hour, adjusting within-day and between-day imprecision and the lifetime of the electrodes. 

In general, the elements to be verified and/or qualified during software implementation... 

From the numerous and partly new functional principles as discussed in previous sections the number and complexity of the peripheral components needed to operate the PIMMS can be estimated. Besides the PIMMS-chip itself and the environment providing an appropriate vacuum the electronic hardware is another very important parameter, which determines the cost and size of the device. As the many subsystems of the spectrometer and their interactions are not standard, in many respects completely new electronic has to be generated to drive the system and read and evaluate the measurements, respectively. To allow real-time applications, such as online control, several hardware components have to work independently from a central controller, which is another challenge for the firmware and software implementation. This section presents an overview on present state of the hardware, firmware, and software infrastructure for the PIMMS and will outline the further steps for industrialization. 

Equation 11.11 and Equation 11.12 are solved sequentially, i.e., in each iterative cycle, the concentration matrix C is calculated and used to get the spectral matrix ST. Both C and ST are solved under constraints, which can be implemented within the least-squares step [57, 58, 60] or external to the least-squares step. In current software implementations of the MCR-ALS method, different constraints can be applied to the C or the ST matrix and, within each of these matrices, all or some of the profiles can be constrained. 

Software implementing the methods described in this chapter are available at the author s website, http //ace.acadiau.ca/math/chipmanh. 

Many elements of a controlled vocabulary are effectively defined by software implementation. Thus, the description of the HTML language requires certain elements to have specified behavior. For example, supports the display of raster images, but the precise look may vary between implementations and file types. Implementation through software is useful and powerful where authors, publishers, readers, and processors all use the same system. Because STM publishing is increasingly multidisciplinary, this implementation becomes problematic. Often a reader may have to download specialist software that is idiosyncratic and that may not have enough functionality, especially the export of semantically rich data. Moreover, the semantic rules are often buried deep in the software and difficult to understand precisely. 

The SBML homepage (http //sbml.org) provides an impressive list of software implementing the notation. The site offers downloads of software libraries that enable easy incorporation to several programming languages (C, C++, Java, Python) as well as mathematics packages (Matlab, Mathematica), and this accessibility has significantly contributed to its success. 

Artificial neural networks are versatile tools for a number of applications, including bioinformatics. However, they are not thinking machines nor are they black boxes to blindly feed data into with expectations of miraculous results. Neural networks are typically computer software implementations of algorithms, which fortunately may be represented by highly visual, often simple diagrams. Neural networks represent a powerful set of mathematical tools, usually highly nonlinear in nature, that can be used to perform a number of traditional statistical chores such as classification, pattern recognition and feature extraction. 

Failure to perform/maintain computer vahdadon in that there was no documentadon to show if the validadon was reviewed prior to software implementation. [FDA Wanung Letter, 2000]... 

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. 

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