Software continued

Software Maintenance is the set of activities (both technical and managerial) necessary to ensure that software continues to meet organizational needs. 

The objective of the requirements of this clause is to ensure that the software continues to meet the software safety requirements specification after modifications. 

Ensure that software continues to meet the software SRS after modifications -12.6.1.1... 

Table 4 Sampling of Universal Resource Locations (URLs) for World Wide Web Server Home Pages of Interest to Computational Chemists Software continued)...

The full dynamical treatment of electrons and nuclei together in a laboratory system of coordinates is computationally intensive and difficult. However, the availability of multiprocessor computers and detailed attention to the development of efficient software, such as ENDyne, which can be maintained and debugged continually when new features are added, make END a viable alternative among methods for the study of molecular processes. Eurthemiore, when the application of END is compared to the total effort of accurate determination of relevant potential energy surfaces and nonadiabatic coupling terms, faithful analytical fitting and interpolation of the common pointwise representation of surfaces and coupling terms, and the solution of the coupled dynamical equations in a suitable internal coordinates, the computational effort of END is competitive. 

Concomitantly with the increase in hardware capabilities, better software techniques will have to be developed. It will pay us to continue to learn how nature tackles problems. Artificial neural networks are a far cry away from the capabilities of the human brain. There is a lot of room left from the information processing of the human brain in order to develop more powerful artificial neural networks. Nature has developed over millions of years efficient optimization methods for adapting to changes in the environment. The development of evolutionary and genetic algorithms will continue. 

With the increase in hardware and software, larger systems can be handled with higher accuracy. Much work will continue to be devoted to the study of proteins and polynucleotides (DNA and RNA), and particularly their interactions with more sophisticated methods. Remember proteins and genes are chemical compounds and sophisticated theoretical and chemoinformatics methods should be applied to their study - in addition to the methods developed by bioinfor-maticians. 

The requiiements for scientific software development have continually increased. Besides the algorithmic core functionality, nowadays there is often a demand for a graphical user interface. In addition to the increasing importance of this visible component, which may still be seen as just an add-on, the software development itself has to fulfill stronger demands on software engineering requirements, such as maintainability and recoverability. 

Another tool relates to presentation We decided to emphasize molecular modeling m the third edition ex panded its usefulness by adding Spartan electrostatic po tential maps m the fourth and continue this trend m the fifth Molecular models and the software to make their own models not only make organic chemistry more ac cessible to students who are visual learners they enrich the educational experience for all... 

Instmmentation advances have increased the power and quahty of the fundamental analytical techniques used in conjunction with LIMS. Unfortunately, these advances come at a price of increasing complexity and volume of information. Despite ah. of the architectural and technological advances of computer hardware and software, the demands of the information requirements still exceed the computing capabhities, so as to put continuing pressure on computer manufacturers to iacrease storage and processiag capabhities evea further. 

A recent trend in particle analysis has been the introduction of personal computer-based automation (3). Sophisticated software packages can be used to automate and speed up the analysis. In some cases these computers can even carry out continuous process control (qv) (see Computer technology). The latest machines also allow the measurements of smaller particles and can detect a wider range of sizes. Machines based on light-scattering principles are being more widely accepted by the industry because of speed. An average analysis takes from 1—2 min, whereas those based on sedimentation principles require from 10—120 min. 

Measurements and Audits. The enabling element of continuous improvement is measurement. An old rule of thumb says that increased accuracy in measuring an energy use ultimately yields a reduction in use equal to 10% of the increased closure of the balance. A basic principle of economics is that any thing that is free is used in excess, ie, an unmetered electrical use is bigger than expected by at least 10%. Metering of the cost elements at each unit in a chemical plant provides effective accountabhity. Measurements should be linked via computer software to production as weh as to weather to result in maximum feedback. 

Follow- Up. Even after the system is deHvered, additional work is usually needed. In conventional software engineering this is viewed as software maintenance or upgrade. It is referred to here as foUow-up to emphasize that the process of knowledge-base refinement that begias ia the prototypiag stage can continue even after the system is commissioned. The need for additional detail may come to light only after the appHcation has been ia use for some period of time. The time required to implement such enhancements should be takea iato accouat. 

Computational fluid dynamics (CFD) emerged in the 1980s as a significant tool for fluid dynamics both in research and in practice, enabled by rapid development in computer hardware and software. Commercial CFD software is widely available. Computational fluid dynamics is the numerical solution of the equations or continuity and momentum (Navier-Stokes equations for incompressible Newtonian fluids) along with additional conseiwation equations for energy and material species in order to solve problems of nonisothermal flow, mixing, and chemical reaction. 

The historical data is sampled at user-specified intervals. A typical process plant contains a large number of data points, but it is not feasible to store data for all points at all times. The user determines if a data point should be included in the list of archive points. Most systems provide archive-point menu displays. The operators are able to add or delete data points to the archive point hsts. The samphng periods are normally some multiples of their base scan frequencies. However, some systems allow historical data samphng of arbitraiy intei vals. This is necessaiy when intermediate virtual data points that do not have the scan frequency attribute are involved. The archive point lists are continuously scanned bv the historical database software. On-line databases are polled for data. The times of data retrieval are recorded with the data ootained. To consei ve storage space, different data compression techniques are employed by various manufacturers. 

Currently, the trend in process control is away from centrahzed process control and toward an increased number of small distributed-control or PLC systems. This trend will put emphasis on the evolution of the fieldbus controller and continued growth of the PC-based controller. Also, as hardware and software improves, the functionality of the controller will increase, and the supporting hardware will be physically smaller. Hence, the traditional lines between the DCS and the PLC will become less distinct as systems will be capable of supporting either function set. 

Assure that the interlock (hardware, software, and I/O) continues to function as designed. The design must also determine the time interval on which this must be done. Often these tests must be done with the plant in full operation. 

Robotics The introduction of robotics has given a new dimension to packaging in that it is now possible to do repetitive tasks with speed and accuracy at notably lower cost than if done by people. The manufacture of robots is well established with corporations of substantial resources providing a quality product with continuity of service, supply, and software support. There is also a specialty industry which is available to supply both accessory hardware and software which are custom designed to handle specific user situations. Economic analysis needs to be done before making the decision as to whether to automate using robots, fixed automation, or the labor of people aided by work aids. 

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