Hierarchical Description Research Articles

MDSplus data acquisition system

MDSplus, a tree based, distributed data acquisition system, was developed in collaboration with the ZTH Group at Los Alamos National Lab and the RFX Group at CNR in Padua, Italy. It is currently in use at MIT, RFX in Padua, TCV at EPFL in Lausanne, and KBSI in South Korea. MDSplus is made up of a set of X/motif based tools for data acquisition and display, as well as diagnostic configuration and management. It is based on a hierarchical experiment description which completely describes the data acquisition and analysis tasks and contains the results from these operations. These tools were designed to operate in a distributed, client/server environment with multiple concurrent readers and writers to the data store. While usually used over a Local Area Network, these tools can be used over the Internet to provide access for remote diagnosticians and even machine operators. An interface to a relational database is provided for storage and management of processed data. IDL is used as the primary data analysis and visualization tool. IDL is a registered trademark of Research Systems Inc.

Object-oriented 3D Modelling, Animation and Interaction

We present an object-oriented 3D graphics and animation framework which provides a new methodology for the symmetric modelling of geometry and behaviour. The toolkit separates the specification of geometry and behaviour by two types of directed acyclic graphs, the geometry graph and the behaviour graph, which are linked together through constraint relations. All geometry objects and behaviour objects are represented as DAG nodes. The geometry graph provides a renderer-independent hierarchical description of 3D scenes and rendering processes. The behaviour graph specifies time- and event-dependent constraints applied to graphics objects. Behaviour graphs simplify the specification of complex animations and 3D interactions by providing nodes for the management of the time and event flow (e.g. durations, time layouts, time repeaters, actions). Nodes contain, manipulate and share instances of constrainable graphical abstract data types. Geometry nodes and behaviour nodes are used to configure high-level 3D widgets, i.e. high-level building blocks for constructing 3D applications. The fine-grained object structure of the system leads to an extensible reusable framework which can be implemented efficiently. © 1997 by John Wiley & Sons, Ltd.

Scaling theorems for zero crossings of bandlimited signals

Scale-space filtering is the only known method which provides a hierarchic signal description method by extracting features across a continuum of scales. One of its important characteristics is that it demands the filtering involved does not create generic features as the scale increases. It has been shown that the Gaussian filter is unique in holding this remarkable property. This is in essence the so-called scaling theorem. In this paper, we propose two scaling theorems for band-limited signals. They are applicable to a broader class of signals and a bigger family of filtering kernels than in Babaud et al. (1986), Yuille et al. (1986) and Wu-Xie (1990). An in-depth discussion of our theorems and the previously published ones is also given.

The vegetation and identification of management units of the Honnet Nature Reserve, Northern Province, South Africa

An analysis of the vegetation of the Honnet Nature Reserve, Northern Province is presented. Releves were compiled in 56 stratified random sample plots. The Braun- Blanquet procedure revealed 12 distinct plant communities and four sub-communities. The Variable Quadrant Plot Method was used in the structural analysis of the communities and management units. The data were ordinated using Detrended Correspondence Analysis (DECORANA) to determine possible relations and gradients between and in the plant communities. Six management units were identified by means of the vegetation ordination, plant communities and the physical environment. A hierarchical classification, description and ecological interpretation of the vegetation units and a descrip- tion of the management units are presented.

Analyzing Nonconvex 2D and 3D Patterns

A nonconvex pattern can be analyzed by describing its concavity regions. These can be identified by computing the difference between the convex hull of the pattern and the pattern itself. A suitable approximation of the convex hull can be obtained by repeatedly filling local concavities of the pattern. Parallel and sequential algorithms are proposed, to fill concavities of 2D and 3D patterns. The resulting approximation of the convex hull is a covering polygon or polyhedron, which is either convex or nearly convex. Exact measures of worst remaining concavities and created protrusions are given. The concavity regions are extracted and different features are presented and computed. Hierarchical pattern descriptions are also suggested, based on the use of concavity trees.

Source coding of wavelet-transformed digital HDTV for recording applications

A novel intraframe source-coding algorithm suitable for the recording of digital high-definition television signals is presented. A multilayered, hierarchical description of the source signal is obtained by means of a quad-tree, halfband wavelet transform. This transform decomposes the input signal into a collection of spectrally nonoverlapping sub-bands. These are used to influence the allocation of the available coding resources to the various layers, so that the integrity of visually significant features can be preserved. Individual sub-bands are quantised and entropy coded by using a predictive arithmetic coding technique. The algorithm is tuned to achieve bit-rate reduction ratios in the range 8 :1 - 4 :1 which is most useful for recording applications. Results obtained from simulating the coding algorithm show noticeable improvement over the current state-of-the-art international standard algorithm for still picture encoding, both in terms of subjective quality and of measured mean-square error.

Intersubject Variability in Functional Neuroanatomy of Silent Verb Generation: Assessment by a New Activation Detection Algorithm Based on Amplitude and Size Information

We present an experimental evaluation of a new algorithm for the detection of activated areas in brain functional maps. The new algorithm, named HMSD, is based on a hierarchical multiscale description of the difference image in terms of connected objects. Size and magnitude of each object are simultaneously tested with respect to a bidimensional frequency distribution derived using Monte-Carlo simulations under the null hypothesis. In the present work. HMSD was applied to the analysis of a silent verb generation PET activation protocol conducted in six right-handed subjects. Applied to single-subject data. HMSD reveals activation located in the left inferior frontal gyrus in three subjects (two in the pars opercularis, one in the pars triangularis), and in the pars opercularis of the right inferior frontal gyrus in one case, the latter being combined to a crossed cerebellar activation. Overall, single-case results were consistent with the analyses of stereotactically averaged data. Despite a 2D implentation. HMSD detection performances of averaged data were better than that obtained with the 2D version of statistical parametric mapping (SPM) and comparable to that of the 3D version of SPM.

Early Image Representation by Slope Districts

Based on the topographic description of slope districts, images can be segmented into a set of regions that is invariant to uniform monotonic scalings of the image. Whereas most previous work relating to slope districts has been restricted to ideal continuous smooth surfaces, this paper describes a robust technique for extracting slope districts from discrete images which is insensitive to variations in the topology of the image. In addition, the image is smoothed over a range of scales to produce a hierarchical description in terms of linked slope districts. At each scale the slope districts are described by attributes such as their image curvature, edge location, and gray-level volume. This image representation is intended as input to subsequent stages of image analysis such as feature grouping and model matching.

The phytosociology of the grasslands of the Ba and Ib land types in the Pretoria–Witbank–Heidelberg area

An analysis of the plant communities of the grasslands of the Pretoria–Witbank–Heidelberg area is presented. Releves were compiled in 148 stratified random sample plots. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed fourteen plant communities, and a hierarchical classification, description and ecological interpretation of these plant communities are presented. Each of these plant communities may be regarded as an entity with a unique species composition, and with specific environmental relationships and an inherent forage production potential. The identification, classification and description of these plant communities are not only important for management purposes, but also for the preservation of biotic diversity.

The OOBP programming paradigm: a VHDL-like object oriented approach toward developing efficient DSP software libraries

After a brief recall of some programming quality criteria, in which the importance of a hierarchical description of systems is underlined, and after a comparative introduction to the use of signal and block abstractions fordsp software development, this paper proposes an original object oriented block programming (oobp) paradigm. The use of encapsulation, inheritance, and polymorphism by itsVHDL-like three design units (namely entity specifications, architectures, and configurations) is exposed. It is shown to fulfil the aforementioned criteria, without the need to incorporate complex schedulers to control asynchronous data flows. Extensions are finally proposed, which provide programmers with optional monitoring facilities.

The grassland vegetation of the Low Drakensberg escarpment in the north-westernKwaZulu-Natal and north-eastern Orange Free State border area

This study of the grasslands of the Low Drakenberg escarpment in the Newcastle–Memel area forms part of theGrassland Biome Project. The 44 relevés compiled in the Fa land type which represents the escarpment, were numer-ically classified (Twinspan), and the results were refined by Braun-Blanquet procedures. The analyses revealed nineplant communities. A hierarchical classification, description and ecological interpretation of the nine plant communities are presented. Hierdie ondersoek van die grasvelde van die Lae Drakensberg platorand in die Newcastle–Memel gebied maak deeluit van die Grasveldbioomprojek. Die 44 relevés wat saamgestel is in die Fa landtipe wat die platorand verteenwoordig, is numeries geklassifiseer (Twinspan) en die resultate is met behulp van Braun-Blanquet prosedures verfyn. Nege plantgemeenskappe is onderskei. ’n Hiërargiese klassifikasie, beskrywing en ekologiese interpretasie van dienege plantgemeenskappe word aangebied.

Complex Fluids and Hierarchical Description (Physics of Systems with Hierarchical Structure)

Complex Fluids and Hierarchical Description (Physics of Systems with Hierarchical Structure)

Digital case library: a resource for teaching, learning, and diagnosis support in radiology.

The authors compiled a digital case library, a database of cases for intracranial masses, that can be used as an electronic teaching file and image source for case-based teaching applications, electronic textbooks, and diagnosis support tools. The library is a relational database with a feature-coded image archive that is structured around relevant radiologic findings. Its index for coding image content is structured as a hierarchical image description index that uses the relational format. Rules that control the search direction within the library and that generate lists of diagnostic hypotheses for decision support tools are embedded within the database structure. Currently, the library consists of 200 cases and 1,100 images that present intracranial masses on radiographs, computed tomograms, magnetic resonance images, and angiograms. Each image in the library is indexed according to its radiologic content. The user may search for reference images that contain particular radiologic features by formulating image content-based queries. The hierarchical index of radiologic findings allows multilevel query formulation that depends on the user's level of experience.

A multiscale model for structure-based volume rendering

A scalar volume V={(x,f(x))|x/spl isin/R} is described by a function f(x) defined over some region R of the 3D space. We present a simple technique for rendering multiscale interval sets of the form I/sub s/(a,b)={(x,f/sub s/(x))|a/spl les/g/sub s/(x)/spl les/b}, where a and b are either real numbers or infinities, and f/sub s/(x) is a smoothed version of f(x). At each scale s, the constraint a/spl les/g/sub s/(x)/spl les/b identifies a subvolume in which the most significant variations of V are found. We use a dyadic wavelet transform to construct g/sub s/(x) from f(x) and derive subvolumes with the following attractive properties: 1) the information contained in the subvolumes are sufficient for reconstructing the entire V; and 2) the shapes of the subvolumes provide a hierarchical description of the geometric structures of V. Numerically, the reconstruction in 1) is only an approximation, but it is visually accurate as errors reside at fine scales where our visual sensitivity is not so acute. We triangulate interval sets as /spl alpha/-shapes, which can be efficiently rendered as semi-transparent clouds. Because interval sets are extracted in the object space, their visual display can respond to changes of the view point or transfer function quite fast. The result is a volume rendering technique that provides faster, more effective user interaction with practically no loss of information from the original data. The hierarchical nature of multiscale interval sets also makes it easier to understand the usual complicated structures in scalar volumes.

Hierarchical ordering in plant morphology

Plants are interpreted as structural hierarchies which are real systems organized through descending constraints. Types of hierarchical groups in plants are (a) cluster by integration, (b) support through attachment, (c) enclosure by encasement (d) dissipative by input of energy and (e) control through variable state switching. Most plant hierarchies are mixtures of these types which explains a number of paradoxes in plant morphology. The traditional means of identifying levels, i.e., cell, tissues, organs, uses a compositional group which is not a hierarchical group but a similarity feature and so is inadequate for describing hierarchies. Hierarchies can be defined by set theory which is more a description of cognitive than real hierarchies and therefore is of little value in describing plant organization. The hierarchical description of a plant emphasizes the immediate physical status of organization which provide, in turn, a physical explanation of development.

APPLYING SYSTEMS ENGINEERING AND ICON‐DRIVEN SIMULATION TECHNIQUES TO THE WASTE DISPOSAL PROBLEM AT HANFORD, WA

AbstractThis paper provides a case study on the use of systems engineering to create the hierarchical description of a decision‐support model for the tank waste remediation program at Hanford, WA. A commercial, off‐the‐shelf (COTS) icon‐driven modeling package is used to sharply reduce the model development effort. A database‐driven information management tool, used to describe the model functions, requirements, architectures and tests, provides the traceability and editing power to document the development with little added effort.

A model‐oriented fault diagnosis system for microprocessor‐based systems

Abstract It is a difficult task to automatically diagnose the faults of microprocessor‐based digital systems, since their functions have rapidly increased. In this paper, we've developed a hierarchical description scheme to model the system under diagnosis (SUD). During the stage of fault identification in our diagnosis system, pseudo‐simulation plays a significant role in evaluating the expected behavior of the SUD. The features of using the pseudo‐simulation approach are not only solving the cyclic problem, but also evaluating a smallest candidate set. During the stage of fault isolation, forward analysis is adopted to analyze the fault propagation path and to generate a plausible candidate set. In addition, an auxiliary test‐assistant board has been designed to handle the test operations. Through the proposed fault diagnosis system, field maintenance and troubleshooting of microprocessor‐based systems has become an easier task.

Towards a hierarchical contour description via dominant point detection

An algorithm for the detection of dominant points and for building a hierarchical approximation of a digital curve is proposed. The algorithm does not require any parameter tuning and is shown to perform well for a wide variety of shapes, including scaled and rotated ones. Dominant points are first located by a coarse-to-fine detector scheme. They constitute the vertices of a polygon closely approximating the curve. Then, a criterion of perceptual significance is used to repeatedly remove suitable vertices until a stable polygonal configuration, the contour sketch, is reached. A highly compressed hierarchical description of the shape also becomes available.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The vegetation and identification of management units of the Imberbe Game Lodge in the mixed bushveld of the north-western Transvaal

An analysis of the vegetation of the Imberbe Game Lodge in the mixed bushveld of the north-western Transvaal is presented. Releves were compiled in 39 stratified random sample plots. Four distinct plant communities were identified by means of Braun-Blanquet procedures. The data were ordinated using detrended correspondence analysis (DECORANA) to investigate possible relationships and gradients in and between the plant communities. Three management units were determined by means of a vegetation ordination. A hierarchical classification, description and ecological interpretation of the plant communities as well as a description of the management units are presented.

Methods of constructing measurement channels in cable television networks

Alternative structures and functional characteristics of an equipment complex and the elements of such a complex that represent a sufficiently complete set of methods for the construction of measurement channels in cable television networks are presented. These results allow us to move to the concluding stage of the design process, the construction of a hierarchical functional and morphological description of alternative equipment complexes together with estimation of the functional and cost performance indicators of these alternatives.