Application Of Routines Research Articles

Electronic structure analysis of (In, Ga, Al) N heterostructures on the nanometre scale using EELS.

In this work the local electronic structure of MOVPE-grown (In, Ga, Al) N heterostructures has been investigated by electron energy loss spectroscopy (EELS). The cold field-emission scanning transmission electron microscope (VG HB501) used was equipped with a dedicated parallel EELS system which provides high dispersions at an energy resolution of 0.35 eV with the use of subnanometre electron probes the spatial resolution of the measurements depends on the physical localization of the scattering process itself and thus is in the order of nanometres. The low-loss region of the energy spectra gives information on plasmon excitations and transitions across the bandgap. The main problem on looking at the bandgap region of EELS spectra is to separate the bandgap signal from the fading tail of the zero-loss peak. High energy resolution and application of suitable deconvolution routines for removal of the zero-loss peak extract improved information from this energy region. Thus the EEL spectra of different group III nitrides reveal the onset of the bandgap itself and the characteristic shape of the joint density of states. From these results the local optical properties can be deduced via a Kramers-Kronig transformation. The data obtained show detailed structure on the energy scale and are in excellent agreement with optical ellipsometric results. In comparison with these techniques EELS methods yield a superior spatial resolution of better than 10 nm which enables detailed investigation of the effect of local defects and boundaries on the optical properties.

Predictive control based on neural network models with I/O feedback linearization

This paper presents an approach for the constrained non-linear predictive control problem based on the input-output feedback linearization (IOFL) of a general non-linear system modelled by a discrete-time affine neural network model. Using the resulting linear system in the formulation of the original non-linear predictive control problem enables to restate the optimization problem as the minimization of a quadratic function, which solution can be found using reliable and fast quadratic programming (QP) routines. However, the presence of a non-linear feedback linearizing controller maps the original linear input constraints onto non-linear and state dependent constraints on the controller output, which invalidates a direct application of QP routines. In order to cope with this problem and still be able to use QP routines, an approximate method is proposed which simultaneously guarantees a feasible solution without constraints violation over the complete prediction horizon within a finite number of steps, while allowing only for a small performance degradation.

An efficient technique for self-term evaluation of the uniform current vector potential integrals

This communication presents an efficient technique for self-term evaluation of the uniform current vector potential integrals which often arise in certain cylindrical wire method of moments formulations. Simple approximating functions, derived from the application of numerical interpolation routines, are introduced that may be used in place of other more complicated techniques for evaluation of these integrals. In particular, this communication will focus on the development of these approximating functions for application in the moderately thick wire regime, where the reduced kernel approximation associated with thinner wires is no longer valid. It is shown that these proposed functions offer reasonably good accuracy over a wide range of wire segment lengths and radii.

AUTOMATED MECHANICAL STIMULATION AND MEASUREMENT OF BIOLUMINESCENCE IN MARINE DINOFLAGELLATES

AbstractA new integrated system for reproducible, automated mechanical stimulation and measurement of bioluminescence (BL) in multiple samples of marine dinoflagellate cell suspensions is described. The system was designed to allow the application of standardized experimental routines to parallel test vials for the purpose of toxicity testing. A sample tray delivered test vials to the position of mechanical stimulation and BL measurement. Mechanical stimulation of BL was applied as sharp rotation‐onset of the test vial about its vertical axis. Thus, any direct chemical or physical perturbation of the cell suspension was avoided. A silicon photovoltaic cell measured the emitted light. Stimulation, measurement and recording of BL were integrated and controlled by specially developed software, which runs on a personal computer in the graphic environment of MS‐Windows. Precise scheduling, flexible programming and identical repetition of experimental routines are possible in practice. For Gonyaulax polyedra, details of BL, as stimulated and measured with the new system, are presented and discussed. We conclude that the system exhibits specific features that offer wide potential of application in several fields of research on dinoflagellate BL, particularly for toxicity testing.

Digitization and image processing methods for enhancement and quantification of grazing-incidence X-ray topographs

The conventional photographic prints obtained from double crystal x-ray topography are often hard to interprete and reproduce. Photographic enhancement methods require skillful work by an experienced photographer. They are time consuming and the image information is difficult to present quantitatively. Alternatively, image processing methods may be applied by digitization of the original topographic recording. Image processing computer programs may be applied, e.g., for image enhancement and for quantification of image information. This paper's main interest is related to-obtaining a sufficiently high magnification ratio;-correcting for intensity variations within the image;-applying spatial filtering techniques in order to reduce film grain noise;-improving contrast, and-retrieving quantative information on image details.The application of such image processing routines is exemplified on topographs obtained by a double-crystal diffractometer set to the (+, -) asymmetric-asymmetric setting. A silicon single crystal was used as the monochromator, while the sample was a silicon single crystal which had undergone both surface damage and metallic contamination before the application of Rapid Thermal Annealing (RTA). Hence, well-defined microdefects are found within the sample. These computer-processed images are compared with corresponding images enhanced by conventional techniques. The results provide indications of which enhancement procedures should be applied for qualitative image improvement and for quantification of image details within different types of topographic recordings.

Direct retrieval of crystal structures by maximum-entropy analysis of incoherent Z-contrast images

Z-contrast imaging of crystalline specimens in a scanning transmission electron microscope (STEM) can provide directly interpretable images of crystal structures at atomic resolution with strong compositional sensitivity. The key feature of the technique is that, by recording images using high-anglethermally diffuse scattered electrons, the resultant image is incoherent, and can be interpreted as aconvolution between the incident electron probe and the projected crystal structure of the specimen. Consequently, the technique is ideally suited to the application of deconvolution routines which enable the retrieval of the original crystal lattice by means of an incident electron probe approximation, and with no prior assumption of the nature of the crystal itself. Here, we show that by applying the image processing technique of maximum entropy, such a retrieval can be achieved with high accuracy,enhancing spatial resolution whilst preserving Z-sensitivity.Maximum entropy is an image processing routine based on Bayesian probability which produces a ‘most likely’ reconstruction of the original image given a particular point spread function, or in this case, electron probe current density distribution.

Digitization and Image Processing Methods for Enhancement and Quantification of Grazing-Incidence X-Ray Topographs

The conventional photographic prints obtained from double crystal x-ray topography are often hard to interprete and reproduce. Photographic enhancement methods require skillful work by an experienced photographer. They are time consuming and the image information is difficult to present quantitatively. Alternatively, image processing methods may be applied by digitization of the original topographic recording. Image processing computer programs may be applied, e.g., for image enhancement and for quantification of image information. This paper's main interest is related to-obtaining a sufficiently high magnification ratio;-correcting for intensity variations within the image;-applying spatial filtering techniques in order to reduce film grain noise;-improving contrast, and-retrieving quantative information on image details.The application of such image processing routines is exemplified on topographs obtained by a double-crystal diffractometer set to the (+, -) asymmetric-asymmetric setting. A silicon single crystal was used as the monochromator, while the sample was a silicon single crystal which had undergone both surface damage and metallic contamination before the application of Rapid Thermal Annealing (RTA). Hence, well-defined microdefects are found within the sample. These computer-processed images are compared with corresponding images enhanced by conventional techniques. The results provide indications of which enhancement procedures should be applied for qualitative image improvement and for quantification of image details within different types of topographic recordings.

Spectroscopic IR ellipsometry of [100] and [001] oriented YBa2Cu3O7−δ films

A spectroscopic technique for IR ellipsometry has been developed. The method is based on a complete Mueller analysis of the optical system and the systematic application of correction routines for experimentally measured Fourier coefficients. As a result the extinction ratio of the polarizers is not crucial for the measurements. Optical properties of microtwinned [100] and [001] oriented YBa2Cu3O7−δ films were studied. Both samples had a thickness of 300 nm and were deposited onto SrTiO3 substrates. The components of the out-of-plane and in-plane permittivity were calculated using data inversion and effective-medium theories for anisotropic grains.

Improved Static Corrections plus Pre-stack Interpretation Improves the Resolution of 2-D Seismic Data

In the quest for improved resolution, the application of good statics routines is often ignored. Using coalfield seismic data, a model independent statics routine which uses the refraction events to align reflections is discussed with examples of its application. Good statics allows improved imaging of 2-D seismic reflection data, which then allows a novel work station method to produce pseudo-3-D volumes from 2-D pre-stack data. Hence subtle features, such as faults with small throws, can be well defined in the pre-stack domain, where they could not be readily observed on the conventional 2-D sections after stack.

Application of GIS Network Routines for Water Flow and Transport

Network routines are implemented within several geographic information systems (GISs). These routines are primarily used in traffic routing and allocation analyses, and very little work has been done on their application in water resources. This paper describes Dijkstra's algorithm, which is used for most network implementations in a GIS and how its routing and allocation techniques can be implemented for water flow and transport. Dijkstra's algorithm is limited by the fact that it requires the resistance to flow be known before the magnitude of the flow is determined, but these two variables are usually interdependent. The consequences of this limitation with regard to water‐resources applications is discussed. The types of problems suitable for GIS water‐network analysis are identified. Three applications—drainage‐network verification and sizing using rational method, watershed isochrone determination, and steady‐state flow computations—are discussed in detail, and their network application within the A...

The exploration of pharmacokinetic and pharmacodynamic data using interactive three-dimensional graphs, a tool borrowed from particle physics

Computerized interactive 3-dimensional graphical displays were originally developed to aid in the exploration of multidimensional data from particle physics experiments. This technique can be equally well applied to speed the analysis of multivariate pharmaco-kinetic and pharmacodynamic data. The application of this technique to the results of a drug study demonstrated its effectiveness in providing a rapid overview of the data and in displaying new perspectives on the multivariate data, helping to identify sources of variability within the study. Multiple concentration-time curves from a given administration period can be distinguished within a single plot, using visual cues provided by rotating the display. Simultaneous comparison of large numbers of curves allows rapid evaluation of intersubject variability. Comparing the concentration-time curves from a single subject, each in succession, quickly identifies sources of intra-subject variability. Manipulating the display by a fourth dimensional parameter shows the degree of relationship between the concentration-time curves and associated dynamic variables. Exploratory analysis using such kinematic display software, provides a rapid, visually concrete impression of the relationships present in kinetic and dynamic data before the application of standard statistical routines.

Pixel overflow artifacts in SPECT evaluation of the skeleton.

The successful application of single photon emission computed tomography (SPECT) techniques to radionuclide evaluation of the skeleton depends on strict quality control measures, recognition of potential artifacts, and the selection of appropriate cases for specific reprocessing techniques. The application of simple image-processing routines to problems of "hot spot" and bladder pixel overflows facilitated a reduction in the technical inadequacy rate from 19% to 2% for SPECT evaluation of 100 hips, as well as improvement in diagnostic image quality in a variety of additional cases.

An Application of Travelling-Salesman Routines to Solve Pattern-Allocation Problems in the Glass Industry

This paper focusses on an often encountered constraint in real-life cutting-stock problems. The constraints require that pieces corresponding to the same order are not spread too much over the production run. This elimination of order spread is called pattern allocation or cutting sequencing. In this paper, a two-stage procedure to solve the two-dimensional pattern-allocation problem is suggested. The first stage consists of solving the cutting-stock problem without the sequencing constraint. In the second stage a sequencing problem is used for the ordering of the cutting patterns in an optimal or near-optimal way. The sequencing problem is formulated as a travelling-salesman model, and the model is solved by Lin's 3-optimal method. Computational experience is reported from a case study in the glass industry.

An Application of Travelling-Salesman Routines to Solve Pattern-Allocation Problems in the Glass Industry

An Application of Travelling-Salesman Routines to Solve Pattern-Allocation Problems in the Glass Industry

An Application of Travelling-Salesman Routines to Solve Pattern-Allocation Problems in the Glass Industry

An Application of Travelling-Salesman Routines to Solve Pattern-Allocation Problems in the Glass Industry

A decision support system for optimizing advertising policy of a national tourist office model outline and case study

Application of standard optimization routines to advertising decision-making is straightforward once the relationship linking market response to input has been modeled adequately. Sometimes, however, advertising management has to cope with decision situations where econometrics fail to detect a reliable relationship. A new decision support procedure eliciting managerial judgments on the pairwise relative importance of market share influence factors provides the factor weights otherwise inaccessible by objective parameter estimation. Allocation of an advertising budget to international travel markets thus becomes susceptible to optimization through dynamic programming.

Allocating an advertising budget to international travel markets

Deciding on advertising appropriations is a common problem to all National Tourist Offices. The Austrian National Tourist Office now employs a decision support model allowing for inclusion of managerial judgments. In tourism, like elsewhere, application of standard optimization routines to marketing decision making is straight- forward, once the relationship linking market response to input has been modeled adequately. A tailor-made decision calculus procedure eliciting managerial judgments on the relative importance of the factors determining a receiving country's travel market share provides the weights otherwise inaccessible by objective parameter estimation. A tourism manager thus can evaluate countries as tourism generators and allocate an advertising budget accordingly.

Diffuse reflectance infrared spectrometry of powdered coals

Diffuse reflectance Fourier Transform infrared spectrometry has been shown to allow spectra of powdered coal samples to be measured at high sensitivity. Quantitative precision is good, so that the rank of individual coals and the composition of coal blends can be determined in <15 min. The degree of oxidation of coals, both for natural oxidation in the seam and for laboratory oxidation, can be determined from diffuse reflectance spectra of coals and from the second derivative of these spectra. Second-derivative spectra allow quantitative estimates of oxidation to be obtained without the application of spectral subtraction routines, which require standard reference samples that are not always available. The potential for using diffuse reflectance infrared spectrometry for monitoring reactions of powdered coals in-situ has been demonstrated.

Concerning the Application of FT-IR to the Study of Coal: A Critical Assessment of Band Assignments and the Application of Spectral Analysis Programs

The problems associated with the application of FT-IR to the characterization of coal structure are critically discussed. The controversies concerning band assignments are considered and it is concluded that the strong 1600 cm−1 band can be assigned to an aromatic ring stretching mode that in most coals is intensity enhanced by the presence of phenolic groups. The application of computer routines to the determination of OH and CH groups is considered. Established criteria for curve fitting are applied to the problem. Qualitative identification of functional groups is achieved, but consistent quantitative measurements will require a determination of the relationship between the extinction coefficients of resolved bands.

Application of the Programmable Calculator to Extension Agricultural Management Programs: Experience from Iowa

The programmable calculator is a recent addition to the set of tools available for performing high speed preprogrammed numerical analysis to aid extension professionals, farmers, and operators of agribusiness firms in management decision making. Multidisciplinary programs were developed and distributed through a subscription library. Evaluation of the library by subscribers indicates that the programmable calculator and software have useful decisionmaking applications for a broad clientele. The tool is valuable for extension workers in preparation for and instruction during meetings, and in direct farmer assistance. Extension economists have long struggled, on the one hand, with making recommendations to farmers on the basis of rules of thumbs, which may become obsolete or lack universal applicability, versus on the other hand, encouraging detailed numerical analysis, which, while providing more precise and individualized answers, often involves laborious and difficult calculations as well. Fortunately, the development of computers and electronic data processing has added a new dimension to decision making in agriculture. A recent addition to the set of tools available to perform high speed numerical analysis is the programmable calculator. This handheld machine can perform all the usual functions and can store a number of variables in memory to be recalled for use in prewritten programs and subprograms that are activated by pressing the appropriate keys. When used with the optional printing hardware, not only can the calculator label and print answers for a permanent record, but it can also be programmed to print questions that will prompt the user to supply necessary facts. Once a program is entered into the calculator, a record can be made by passing a magnetic card through a slot in the calculator. The program can be reentered into the calculator at any time by simply inserting this permanent magnetic card through the same slot. Several manufacturers build programmable calculators. At present, memory capacity ranges up to one hundred values and nearly one thousand programming steps. However, rapid advances in capacity and capabilities have been made in recent years and probably will continue to be made. Some models, such as the Texas Instruments TI-58 and TI-59, also have internal solid-state module libraries that contain permanently stored programs accessible directly from the keyboard. DEVELOPMENT OF COMPUTERIZED MANAGEMENT AIDS Computer programs for extension activities have been available for a number of years. Early efforts centered on large models processed in a batch system. One common example was the application of linear programming routines for farm enterprise selection [1]. Operational problems in transferring data from the client to the computer (usually located on a university campus) and back were somewhat alleviated by the introduction of remote terminals that transmit data to and from the central computer via telephone [2]. A number of states now have systems available for utilizing computer management aids through remote timesharing terminals [5]. A recent study by LaDue in New York state compared alternative remote access systems and indicated that these systems have a positive impact on extension programs. LaDue showed that the systems allow extension agents to handle management problems more quickly and accurately. Easy access and instant turnaround are important for making timely decisions. Use of such a tool may create a whole new type of service to be offered by local extension staffs [5]. The next logical step in hardware development has been to put computing capability in the hands of the clientele. Putting remote terminals in farmers' homes has been proposed, as has use of the micro-computer, one of the fastest selling consumer items in existence today. The micro-computer can free the farmer from dependence on telephone connections and on extension agents for routine analyses. To date their adoption has been limited primarily by a lack of available software [3]. James M. McGrann is an associate professor of agricultural economics at Texas A&M University, and William M. Edwards is an assistant professor of economics at Iowa State University. The authors acknowledge the contribution of members of the faculty of the Department of Animal Science at Iowa State University, the extension field staff in Iowa, and three anonymous reviewers, who made helpful suggestions. This content downloaded from 157.55.39.177 on Tue, 15 Nov 2016 04:02:47 UTC All use subject to http://about.jstor.org/terms 148 NORTH CENTRAL JOURNAL OF AGRICULTURAL ECONOMICS, Vol. 1, No. 2, July 1979 THE PROGRAMMABLE CALCULATOR The programmable calculator offers many of the same advantages as a micro-computer only in a less expensive and simpler package. The experience of the authors has been that, while it cannot completely replace others types of computerized management aids, it is readily accepted and utilized as a decision tool by farmers and agribusinessmen.