Graphical Map Research Articles

WebMap: a graphical hypertext navigation tool

WebMap is intended to help avoiding the well-known “lost in hyperspace” situation. It does this by creating and updating a two-dimensional graphical map of a user's “journey through hyperspace” by dynamically analyzing the navigation actions. WebMap communicates with the Mosaic WWW browser, so user interactions with Mosaic are immediately reflected in WebMap's graphics window. WebMap also may be used to control Mosaic, e.g., to cause it to load a new document into one of its windows or store a document in PostScript format.

Dynamically Loaded Journal Bearings: Position of Maximum Pressure Ratio

The position of the maximum “pressure ratio” in dynamically loaded bearings, using short bearing theory, has previously been published only in graphical (map) form. Simple equations are derived here so that this position (relative to the load line) can be obtained directly in numerical form.

Some mathematical and computer modelling of neural networks

The purpose of this paper is to provide a brief background on neural networks, a summary of the mathematical models for some learning rules for neural networks, and some new computer graphics for these. The applications of these learning rules include both Boolean and continuous functions, as well as the construction of graphical mappings of the sensorary space as a two-dimensional neural grid. Numerical interpretations of the computer graphics generated for each of these learning rules are provided to serve as a guide for comparisons. The application of neural networks to solving the travelling salesman problem (TSP) is also discussed, as well as the method of simulated annealing. Computer graphics are provided for solutions to the TSP and also for activation of an output neuron for a three-layer feed-forward network which is trained using a Boolean function. Conclusions and future directions of the research are discussed.

The morphoelectrotonic transform: a graphical approach to dendritic function

Electrotonic structure of dendrites plays a critical role in neuronal computation and plasticity. In this article we develop two novel measures of electrotonic structure that describe intraneuronal signaling in dendrites of arbitrary geometry. The log-attenuation Lij measures the efficacy, and the propagation delay Pij the speed, of signal transfer between any two points i and j. These measures are additive, in the sense that if j lies between i and k, the total distance Lik is just the sum of the partial distances: Lik = Lij + Ljk, and similarly Pik = Pij + Pjk. This property serves as the basis for the morphoelectrotonic transform (MET), a graphical mapping from morphological into electrotonic space. In a MET, either Pij or Lij replace anatomical distance as the fundamental unit and so provide direct functional measures of intraneuronal signaling. The analysis holds for arbitrary transient signals, even those generated by nonlinear conductance changes underlying both synaptic and action potentials. Depending on input location and the measure of interest, a single neuron admits many METs, each emphasizing different functional consequences of the dendritic electrotonic structure. Using a single layer 5 cortical pyramidal neuron, we illustrate a collection of METs that lead to a deeper understanding of the electrical behavior of its dendritic tree. We then compare this cortical cell to representative neurons from other brain regions (cortical layer 2/3 pyramidal, region CA1 hippocampal pyramidal, and cerebellar Purkinje). Finally, we apply the MET to electrical signaling in dendritic spines, and extend this analysis to calcium signaling within spines. Our results demonstrate that the MET provides a powerful tool for obtaining a rapid and intuitive grasp of the functional properties of dendritic trees.

Mapping success

To re-engineer a company the processes by which business is performed must be defined and challenged. The author introduces process mapping as a route to business excellence. The objective of process mapping is to describe business processes, using symbolic notation, on paper or in computer software. The resulting graphical map will identify the activities that occur in performing each process together with relevant details of the activities.

Examination of a target organ texixity with the multidimensional graphical and statistical mapping method

Endocrine disrupting chemicals (EDCs) have become a major issue in the field of environmental science due to their ability to interfere with the endocrine system. Recent studies show that surface water is contaminated with EDCs, many released from wastewater treatment plants (WWTP). This pilot study used biological (E-screen assay) and chemical (stir bar sorptive extraction–GC–MS) analyses to quantify estrogenic activity in effluent water samples from a municipal WWTP and in water samples of the recipient river, upstream and downstream of the plant.The E-screen assay was performed on samples after solid phase extraction (SPE) to determine total estrogenic activity; the presence of estrogenic substances can be evaluated by measuring the 17-β-estradiol equivalency quantity (EEQ). Untreated samples were also assayed with an acute toxicity test (Vibrio fischeri) to study the correlation between toxicity and estrogenic disruption activity.Mean EEQs were 4.7 ng/L (± 2.7 ng/L) upstream and 4.4 ng/L (± 3.7 ng/L) downstream of the plant, and 11.1 ng/L (± 11.7 ng/L) in the effluent. In general the WWTP effluent had little impact on estrogenicity nor on the concentration of EDCs in the river water. The samples upstream and downstream of the plant were non-toxic or weakly toxic (0 < TU < 0.9) while the effluent was weakly toxic or toxic (0.4 < TU < 7.6). Toxicity and estrogenic activity were not correlated.At most sites, industrial mimics, such as the alkylphenols and phthalates, were present in higher concentrations than natural hormones. Although the concentrations of the detected xenoestrogens were generally higher than those of the steroids, they accounted for only a small fraction of the EEQ because of their low estrogenic potency. The EEQs resulting from the E-screen assay and those calculated from the results of chemical analyses using estradiol equivalency factors were comparable for all samples and closely correlated.

Instructional Approaches and Interventions that can Improve the Academic Performance of African American Students

GENERAL INSTRUCTIONAL APPROACHESCOMPREHENSION-DEVELOPMENT INSTRUCTIONAL STRATEGIESData collected by National Assessment of Educational Progress and other organizations indicate that average achievement levels of African American students are distressingly low, particularly with respect to higher-order comprehension and thinking skills (Cooper & Levine, 1993; Levine & Eubanks, 1990). During past two decades or so, educators have developed and/or refined instructional strategies that many observers believe provide us with capacity to bring about virtually a revolution in successfully developing comprehension and thinking skills of students whose performance currently is unsatisfactory in reading, history, mathematics, science, and other subjects (C. Block, 1993; Idol & Jones, 1991; Means, Chelemer, & Knapp, 1991; Pearson, 1985). Some of most prominent of these instructional strategies include use of graphic organizers, semantic webbing and mapping, inferencing and prediction techniques, and summarization guidelines (C. Block, 1993; Levine & Sherk, 1989). Assisting faculties to learn how to use these strategies and introduce them as part of regular classroom typically requires a large-scale, continuing staff development effort; considerable technical assistance; and improvements in school climate, leadership, expectations for students, and other characteristics or correlates of unusually effective schools. However, impressive gains have been registered thereby in performance of students, particularly those who otherwise would be low achievers or at risk of dropping out of school (C. Block, 1993; Cooper & Levine, 1993; Levine & Lezotte, 1990, 1994; Levine & Sherk, 1989; Means, Chelemer, & Knapp, 1991).The results of a recent study by Knapp, Shields, and Turnbull (1992) support conclusion that instructional strategies stressing comprehension and thinking can improve achievement of disadvantaged students. Knapp et al. examined effects of emphasizing or not emphasizing meaning and understanding in 140 elementary classrooms with high percentages o poverty students. They offer following generalizations regarding implications for design and conduct of instruction in schools with a high proportion of students from low-income families:The findings dispel myth that, for most of children of poverty, academically challenging work in mathematics and literacy should be postponed until they are ready--that is, until they have acquired full mastery of basic skills. Although such students are often lacking in certain basic skills, they can acquire these skills at same time that they gain advanced skills (which provide a broader, more meaningful context for learning the basics). (p. i)Indeed, instructional practices aimed at developing meaning and understanding provide avenues for teachers to expand their repertoires. Those who wish to do so can expand their practices provided they receive appropriate mix of encouragement, support, and flexibility.COMPUTER-ASSISTED INSTRUCTION AND OTHER TECHNOLOGY-BASED APPROACHESOne good example of a technology-based approach designed specifically to help students acquire skills and knowledge necessary to become independent thinkers and learners is anchored instruction approach being developed by Cognition and Technology Group (CTG) (1990). Anchored aims to create problem-solving environments based on use of videodisc and computer technologies that provide a framework for sustained exploration of authentic tasks (p. 2). CTG's initial work has involved painstaking creation of videodiscs, computer software, and instructional materials designed to improve average- and low-achieving students' problem-formulation and problemsolving capacities as well as various comprehension and communications skills. Students work cooperatively in small groups much of time, and guidance in learning-to-learn is provided by both teacher and technology. …

Efficient mapping from neuroanatomical to electrotonic space

Previous studies documented the importance of electrotonic structure in single-neuron computations. Here we elaborate a new approach to electrotonic theory and analysis. We begin with a more versatile measure Lij of the electrotonic distance between any two locations i and j on a neuron. If Vi is the voltage at the origin and Vj is the voltage at Some other point, the electrotonic distance is Lij=ln(Vi/Vj). Voltage decays e-fold per unit of L for any two points on the neuron, regardless of its electrotonic architecture. Lij increases as the sinusoidal frequency of Vi increases. If j lies on the direct path between i and k, then Lik=Lij+Ljk. This relation enables electrotonic transforms of the neuron—graphical mappings from neuroanatomical to electrotonic space. For each neuron, there exists an infinite number of such transforms, which can be done from any reference location on the neuron, as a function of voltage transfer to or from that location, and for any frequency of input signal. Sets of these trans...

The salivary gland chromosomes of Drosophila virilis: a cytological map, pattern of transcription and aspects of chromosome evolution.

By combining information from microscopical observation and photography a graphical map of Drosophila virilis salivary gland chromosomes was constructed. About 1,560 individual bands are shown and patterns of transcription at about 360 sites are indicated. The application of the map is demonstrated by using genetic, morphological and in situ hybridization data to identify the white-Notch regions of D. virilis and Drosophila melanogaster as homologous chromosome segments with constant and variable features.

Directional mathematical morphology and reformalized Hough transformation for the analysis of topographic maps

One of the most difficult and important problems encountered in the automatic digitizing of graphical topographic maps is the identification and separate digitizing of different kinds of features. Essentially, in topographic maps, there are two kinds of geometric features: linear features, such as roads and railways that have an arbitrary length, and symbols, which indicate a type of building or area of land usage or even numerical information. These two types of features are extracted and recognized by using methods based on multiangled parallelism (MAP). The MAP operation method performs parallel calculation on directional feature planes. The linear features are extracted using erosion-dilation operations on the directional feature planes, and the symbols are extracted using a reformalized and parallel version of the generalized Hough transformation on the same directional planes, which is called the MAP matching method. The methods have been applied to a 1/25000 scale map. >

Acoustic Excitation of Diffusion Flames with Coherent Structure in a Plane Shear Layer. Application of Active Combustion Control to Two-Dimensional Phase-Locked Averaging Measurements.

In the previous paper, it was shown that the acoustic excitation of a plane diffusion flame enhances the periodicity and intensity of organized-eddy-controlled combustion. The main objective in this paper is, thus, to examine phase characteristics of the excited eddy flames with high periodicity. A computer-aided phase-locked averaging method is employed to obtain graphical 2D contour maps of the instantaneous profiles of temperature and CH emission. Both maps of eight consecutive phases indicate clearly not only the periodic behavior of the organized eddy flame, but also the gas dynamic properties peculiar to those flames with coherent structure. The profiles of local contribution of the sound field to the combustion process are also examined by calculating the 2D distribution of the local Rayleigh index. The latter shows that the organized eddy flames have high sensitivity to sound, and play an important role in a sound-flame interaction.

DNA Translator and Aligner: HyperCard utilities to aid phylogenetic analysis of molecules.

DNA Translator and Aligner are molecular phylogenetics HyperCard stacks for Macintosh computers. They manipulate sequence data to provide graphical gene mapping, conversions, translations and manual multiple-sequence alignment editing. DNA Translator is able to convert documented GenBank or EMBL documented sequences into linearized, rescalable gene maps whose gene sequences are extractable by clicking on the corresponding map button or by selection from a scrolling list. Provided gene maps, complete with extractable sequences, consist of nine metazoan, one yeast, and one ciliate mitochondrial DNAs and three green plant chloroplast DNAs. Single or multiple sequences can be manipulated to aid in phylogenetic analysis. Sequences can be translated between nucleic acids and proteins in either direction with flexible support of alternate genetic codes and ambiguous nucleotide symbols. Multiple aligned sequence output from diverse sources can be converted to Nexus, Hennig86 or PHYLIP format for subsequent phylogenetic analysis. Input or output alignments can be examined with Aligner, a convenient accessory stack included in the DNA Translator package. Aligner is an editor for the manual alignment of up to 100 sequences that toggles between display of matched characters and normal unmatched sequences. DNA Translator also generates graphic displays of amino acid coding and codon usage frequency relative to all other, or only synonymous, codons for approximately 70 select organism-organelle combinations. Codon usage data is compatible with spreadsheet or UWGCG formats for incorporation of additional molecules of interest. The complete package is available via anonymous ftp and is free for non-commercial uses.

Mid‐ and low‐latitude model of thermospheric emissions: 1. O+ (²P) 7320 Å and N2 (2P) 3371 Å

The capability has been developed to model thermospheric airglow emissions on a semiglobal scale (L &lt; 5). This model produces volume emission rates as a function of altitude, latitude, longitude, and local time for any selected date, and solar and magnetic conditions. The model can thus be used to provide three‐dimensional maps of the selected emission for comparison with data obtained from orbiting vehicles. As such it becomes an essential tool in the planning and interpretation of airglow observations. A unique feature of the model is that it incorporates full interhemispheric coupling by solving all the appropriate coupled equations along the magnetic flux tubes from the mesosphere in one hemisphere to the mesosphere in the other hemisphere. As a result the effects of conjugate photoelectrons (and heat fluxes) can be fully explored. In this paper we select two thermospheric emissions with which to demonstrate the capability. The first is the 7320‐Å emission from the metastable O+ (²P). The second is the permitted emission at 3371 Å from the N2 second postive 0–0 band. These two emissions, for which the photochemistry is relatively well understood, are used to show the seasonal, diurnal and solar cyclic variations on a scale that covers mid‐ and low‐latitudes, and the effects of interhemispheric coupling (conjugate photoelectrons).

A vector and raster graphic mapping tool on micro-computers

AbstractThe rapid development of physically-based hydrological information and modelling systems has necessitated enhanced data entry and display systems. A 'mapping tool' is developed for the manipulation and display of spatial information, which is a cost-efficient, self-contained utility system that is suitable for use on micro-computers. It has the ability to be integrated as part of any modelling or information system. Diverse applications using the 'mapping tool' are briefly described including resource management systems for planners, mass balance studies in urban catchments and data entry systems for physically based models.

A vector and raster graphic mapping tool on micro-computers

A vector and raster graphic mapping tool on micro-computers

A numerical investigation of the one-dimensional newtonian three-body problem II. Positive energies

Numerical orbit integrations have been conducted to characterize the types of trajectories in the one-dimensional Newtonian three-body problem with equal masses and positive energy. At positive energies the basic types of motions are “binary + single particle’ and ‘ionization’, and when time goes from −∞ to +∞ all possible transitions between these states can take place. Properties of individual orbits have been summarized in the form of graphical maps in a two-dimensional grid of initial values. The basic motion types exist at all positive energies, but the binary + single particle configuration is obtained only in a narrow region of initial values if the total energy is large. At very large energies the equations of motion can be solved approximately, and this asymptotic result, exact in the limit of infinite energy, is presented.

“Desktop Knowledge”: A New Focus for Medical Education and Decision Support

Physicians today are faced with "data overload" and, paradoxically, "information underload"--the inability to locate pertinent, needed knowledge in a sea of data with which they are inundated. Increasingly, the professional functions of the physician are becoming focused on the desktop workstation, in terms of its ability to provide "windows" into local databases and knowledge resources, and to serve as an access port to other networked resources. A challenge we now face is to develop means for structuring the vast potentially available knowledge resources in such a manner that access to pertinent knowledge can be facilitated, and to develop acceptable interfaces to the knowledge resources so that a user can effectively navigate through them. The complexity of this task is due to the nature of the knowledge resources--knowledge can be in a variety of forms, ranging from textual and pictorial material, to structured representations, to more dynamic embodiments in the form of procedures. In the Decision Systems Group we have focused on the development of a prototype desktop knowledge management environment known as Explorer-2, with the objective of providing a consistent interface for access to a wide variety of knowledge. Our accomplishments to date encompass the incorporation into the Explorer-2 environment of adaptations of textbook chapters and books, image data bases, simulations, and expert systems. Navigational aids are provided by a semantic net browser using both MeSH and augmented taxonomies and by a graphical overview map.(ABSTRACT TRUNCATED AT 250 WORDS)

STEREOSCOPIC SUPERIMPOSITION

AbstractThe replacement of the graphical map by geographic information systems has modified the requirements in photogrammetric data acquisition. An important element in this context is the possibility of superimposing a digital map into the oculars of photogrammetric measuring systems. The Institute of Photogrammetry, at EPF‐Lausanne, in collaboration with the Institute of Micro‐Informatics and Wild Heerbrugg Ltd., has developed a device for stereoscopic superimposition which is integrated into the photogrammetric measuring system of the Wild S9‐AP. The technical requirements of a stereoscopic superimposition system concerning image quality and scrolling are discussed, followed by a description of the technical implementation and the functioning of the superimposition system. Finally, the operation of the System 9‐AP and various applications are presented.

Truncation error bounds for modified continued fractions with applications to special functions

Much recent work has been done to investigate convergence of modified continued fractions (MCF's), following the proof by Thron and Waadeland [35] in 1980 that a limit-periodic MCFK(a n , 1;x 1), with $$\mathop {\lim }\limits_{n \to \infty } a_n = :a \in \mathbb{C} - ( - \infty , - \tfrac{1}{4}]$$ andnth approximant $$g_n = S_n (x_1 ) = \frac{{a_1 }}{1} + \frac{{a_2 }}{1} + \cdots + \frac{{a_{n - 1} }}{1} + \frac{{a_n }}{{1 + x_1 }},$$ converges more rapidly to its limitf than the ordinary reference continued fractionK(a n /1) withnth approximantf n =S n (0). Herex 1 denotes the smaller (in modulus) of the two fixed points ofT(w)=a/(1+w). The present paper gives truncation error bounds for bothf n andg n that exploit the limit-periodic property lima n =a. Certain a posteriori bounds given forg n are shown to be best possible, relative to the given (limited) information available. This is the first instance in which truncation error bounds for this problem have been shown to be best possible. Also included in this paper are results on speed of convergence, a practical method for constructing the bounds, and applications to a number of special functions. The given numerical examples indicate that the error bounds are indeed sharp. For the function arctanz, we give graphical contour maps of the number of significant digits in the approximationsf n (z),g n (z) andp n (z), thenth partial sum of the Maclaurin series, forz in a key region of the complex plane. These maps help us compare the various approximations with each other and add to our understanding of their convergence behavior.

Radiative transfer calculations for characterizing obscured surfaces using time-dependent backscattered pulses

Numerical calculations for estimating the albedo of a surface and its distance behind an obscuring multiplescattering atmosphere are performed for the idealized case of an instantaneous pulse uniformly illuminating a plane-geometry atmosphere of known properties. This inverse problem is complicated by the fact that the backscattered irradiance is broadened in time because of purely geometric effects arising from the geometry considered; the broadening increases with an increasing thickness of the obscuring medium and if the medium scatters in a more isotropic manner, such as with Rayleigh scattering. Isocline maps of different observables suggest that graphical inversion maps might be useful for some applications of this type.