Hierarchical Description Research Articles

UML behavioral consistency checking using instantiable Petri nets

Model-driven engineering (MDE) development methods are gaining increasing attention from industry. In MDE, the model is the primary artifact and serves several goals, including code generation, requirements traceability, and model-based testing. MDE thus enables cost-effective building of models versus direct coding of an application. Thus model-based formal verification of behavioral consistency is desirable as it helps improve model quality. Our approach is based on translation of a UML model to instantiable Petri nets (IPN). This formalism is based on the semantics of Petri nets, but introduces the concepts of type and instance. This allows one to accurately capture these concepts in UML models. IPN support hierarchical descriptions natively, and use the notion of transition synchronization for composition of behaviors. This is a general and powerful mechanism borrowed from process algebra. We show that IPN allow one to adequately address the challenges of translation from UML for analysis purposes. The approach has been implemented and experimental results are presented.

A‐WING: an ad hoc wireless inter‐network gateway

AbstractThis paper presents a design and implementation of a novel ad hoc wireless inter‐network gateway and research platform (A‐WING) which supports heterogeneous wireless and wired networking infrastructures and ad hoc wireless protocols. The driving goal is to explore and realize ways of increasing the ‘always best connected’ options for mobile wireless devices. The platform currently supports IEEE 802.11 (Wi‐Fi), IEEE 802.3 (Ethernet), Bluetooth, IPv4, IPv6, broadcasting and multicasting, stream and datagram transport protocols. The gateway can be readily expanded by the addition of new functionality or support for other networking hardware. This functional variety and inbuilt extensibility ensures that A‐WING can facilitate research into multi‐mode multi‐protocol wireless networking. The A‐WING design is based on a new generic description of link layer services called the ‘9Cs’ and includes a new method for the hierarchical description of networks incorporating nodes with multiple interfaces together with the development of a new XML schema for network, node and interface descriptive inter‐nodal messaging. Copyright © 2008 John Wiley & Sons, Ltd.

Identifying the most stable networks in polyhedral water clusters

We present a new discrete model to identify the most stable networks in polyhedral water clusters. The model relies on the screening of the energy of the local network based on the concept of ‘strong’/‘weak’ nearest neighbor interactions according to their ( trans/ cis) orientation and the connectivity of the respective pairs to neighbors. We apply this model to the pentagonal dodecahedron (H 2O) 20 cluster using a hierarchical description of the intermolecular interactions using classical interaction potentials and several levels of electronic structure methods. This study offers a practical and efficient approach for identifying stable networks in clathrate hydrate structures.

Attributes Selection in Chinese Ontology Acquisition with FCA

An ontology can be seen as a hierarchical description of concepts in a specific domain. One of the key issues in ontology construction is the acquisition of ontology hierarchy. Manual construction of ontology by experts is time-consuming and costly, and timely update is also difficult. In automatic or semi-automatic methods, the general procedure of ontology construction is to obtain domain specific terms first and then acquire the relations among them. Terms can be obtained through terminology extraction. Relationship among terms can then be acquired to construct an appropriate ontology hierarchy. Formal Concept Analysis (FCA) is an effective tool for the acquisition and visualization of ontology structure. In using FCA to acquire ontology structure, some existing methods are inclined to use a single type of attributes such as verbs or nouns or adjectives in the context of a term. This paper investigates the use of context words including nouns, verbs, adjectives, and adverbs as well as their combination. Experiments on a general corpus and a domain specific corpus show that the combined attributes of content word types give the best performance. Contrary to the belief that verbs serve as the best single type of attributes, nouns are better to use as they have overall better average performance over the whole spectrum of threshold values. Another experiment is conducted to examine context words which are qualified as domain specific terms from a so-called Core Term List which is acquired separately. The Core Term List contains terms complying with some specific standards as qualified domain terms. Experiments show a comparable or even better performance of using the Core Term List as context than using dynamically acquired nouns. In fact the core Term List approach gives comparable result to the combined content words. Thus, simple domain knowledge acquired apriori can serve as a good alternative attribute set especially in resource limited cases.

Activity Modeling for Integrating Environmental, Health and Safety (EHS) Consideration as a New Element in Industrial Chemical Process Design

In this paper, we present activity models of chemical process design integrating environmental, health and safety (EHS) evaluation as a new element with conventional economic and technical considerations on the basis of the design framework, which defines different stages of early process design with appropriate indicators for multiobjective evaluation. The type-zero method of Integrated DEFinition language or IDEF0 is selected as an activity modeling method for the hierarchical and transparent description of complex design activities. The viewpoint of the activity model is the user of this design framework, i.e. a design-project manager who leads a group of process chemists and engineers. A set of template models is developed, which describes how a manager executes a project step by step with providing instructions and resources appropriately. According to this template, IDEF0 models of the design framework are created, and here EHS-related activities, tools and information are systematically defined as a part of the whole design activity. As further analysis, sub-activities are presented in detail, where the manager allocates resources appropriately to different design stages, including methods of environmental Life Cycle Assessment (LCA) and EHS hazard evaluation. Another detailed analysis is on how design constraints, e.g., market situation, competitors’ patents and company culture, affect different decision-making within the framework. The actual development of methyl methacrylate (MMA) processes is investigated as a case study. The paper finally presents important know-how for the design manager in executing the integrated design framework.

Hierarchical detailed description for spatial direction relations

Direction relation is an important spatial relation. Descriptions and representations for direction relations have different levels of detail because of the varying dimensions of spatial objects and different scales of the embedding spaces. Based on a direction-relation matrix, the hierarchical frame of spatial direction relations which partitions direction relations orderly and thoroughly is built. Interior direction relations are used to perfect the representation of direction relations and the binary-encoding idea is creatively applied to construct an interior detailed matrix describing multiple interior direction relations by a uniform matrix. The model integrates topological information into the description model for direction relations, which will lay the foundations of spatial compositive reasoning.

Modelling and simulation of complex workflow processes using multi-level Petri nets

A method for modelling complex workflow processes using a Petri Net (PN) based multilevel formalism is proposed; it yields modular and hierarchical descriptions of the organisation (or network of organisations), the processes, resource management and user interactions. The models allow the synthesis of agent based software in which mobile agents guide the cases through the organisation units; the software can be interactively executed for simulation purposes or distributed within a computer network for implementing a workflow management system. A tool for editing and simulating the models is presented.

2P-287 Motion tree法による蛋白質構造変化の階層的記述(生命情報科学・構造ゲノミクス,第46回日本生物物理学会年会)

2P-287 Motion tree法による蛋白質構造変化の階層的記述(生命情報科学・構造ゲノミクス,第46回日本生物物理学会年会)

모양 기반 영상검색을 위한 골격 나무 구조

본 논문에서는 내용기반 영상검색 시스템에서 검출 정확성을 개선하기 위한 모양 기반 객체 표현 기법인 골격 나무 구조와 골격 나무 구조에 기반한 검색 기법을 제시한다. 모양의 표현을 위한 새로운 골격 나무 표현 기법은 객체의 모양을 계층적인 나무 구조로 표현한다. 나무 구조에서의 상위 레벨의 노드들은 객체 모양의 대략적인 몸체를 표현하고 하위 레벨의 노드들은 객체 모양의 세밀한 부분을 표현한다. 대부분의 영상 잡음 영향은 하위 레벨의 노드들에 국한되므로 외곽선 잡음의 영향은 하위 레벨에 대한 가중치를 조절하여 감소시킬 수 있다. 두 골격 나무의 유사성은 두 나무의 골격 노드들을 매칭하여 계산된다. 두 골격 노드들의 집합이 표현하는 영역의 유사성 계산을 위해서 Zernike 모멘트 불변량과 Fourier 기술자 불변량의 조합이 사용된다. 검출의 정확도를 다른 유사성 측도와 비교하고 그 결과를 제시하였다. 실험 결과 제안된 검색 기법의 검출 정확도가 증가하였음을 알 수 있었다. This paper proposes a skeleton-based hierarchical shape description scheme, called a skeleton tree, for accurate shape-based image retrieval. A skeleton tree represents an object shape as a hierarchical tree where high-level nodes describe parts of coarse trunk regions and low-level nodes describe fine details of boundary regions. Each node refines the shape of its parent node. Most of the noise disturbances are limited to bottom level nodes and the boundary noise is reduced by decreasing weights on the bottom levels. The similarity of two skeleton trees is computed by considering the best match of a skeleton tree to a sub-tree of another skeleton tree. The proposed method uses a hybrid similarity measure by employing both Fourier descriptors and moment invariants in computing the similarity of two skeleton trees. Several experimental results are presented demonstrating the validity of the skeleton tree scheme for the shape description and indexing.

Mécanismes de défense et dépression du sujet âgé institutionnalisé

Introduction This study was designed to investigate the links between defence mechanisms and the increase of elderly patient’s depression levels in nursing homes. This research is motivated by the common assumption that the depression level of elderly persons increases in nursing homes (see the AGED study) yet we still have only a few insights about the psychological mechanisms involved. We focused on unconscious defence mechanism models to examine the assumption that the increase in depression levels in nursing homes could reflect the involvement of elderly persons in an adaptive process helping them to deal with the psychological consequences of institutionalisation. Based on the hierarchical and empirical description of defence mechanisms, we postulated that institutionalisation promotes both an increase in depression levels and in immature defence styles. In regard to previous works, we also explored the links between anxiety personality traits, depression levels and defence mechanisms. Method Our sample ( N = 39) was subdivided into two subgroups (group 1: nursing home vs group 2: elderly persons living in communities). Assessments included the French versions of the Geriatric Depression Scale (GDS), the State and Trait Anxiety Inventory (STAI) and the Defence Style Questionnaire (DSQ). Statistical analyses We used the Mann-Whitney formula to compare the two independent groups, and we used the Spearman-Pearson method to perform correlation analyses. Results Two-group comparisons revealed significant increases in depression and anxiety state in nursing homes. Furthermore, elderly persons who are institutionalised exhibit a greater tendency to use regression and help-rejecting complaining defence mechanisms. We performed two distinct correlation analyses matrices with regard to the subjects’ status (nursing-home vs living at home). In both groups, the anxiety-trait is positively correlated with anxiety-state and depression. In elderly person groups living in communities the regression defence mechanism is positively linked with anxiety-trait and depression, while data from aged people groups who are institutionalised reveal a positive link on one hand, between anxiety-trait and regression and on the other hand, between depression and omnipotence defence mechanisms. Discussion Our results confirm that nursing-home placement can constitute a risk-factor for an increase in depression and anxiety state for elderly persons. Institutionalisation favours the use of unconscious immature defences altering social relationships by a tendency to retire within oneself (regression) and by expressing complaints. Interestingly, neither regression nor help-rejecting complaints are significantly correlated with psychiatric outcomes in nursing homes. However, a lower depression level is associated with a higher tendency to overvalue one’s ability to influence one’s life (omnipotence). This negative link could reflect either the adaptive value of omnipotence that restores the sense of control of aged people, or the GDS limits in rating major signs of elderly persons’ depression. In this case, it would be of interest to assess one’s hypomania tendency and to explore links with an increase in use of omnipotence. Based on the correlations reported between anxiety trait, defence mechanisms and psychiatric outcomes, we discussed the interactions between personality and environment in determining behaviour and psychological mechanisms in nursing homes.

Learning function-based object classification from 3D imagery

We propose a novel scheme for using supervised learning for function-based classification of objects in 3D images. During the learning process, a generic multi-level hierarchical description of object classes is constructed. The object classes are described in terms of functional components. The multi-level hierarchy is designed and constructed using a large set of signature-based reasoning and grading mechanisms. This set employs likelihood functions that are built as radial-based functions from the histograms of the object instances. During classification, a probabilistic matching measure is used to search through a finite graph to find the best assignment of geometric parts to the functional structures of each class. An object is assigned to the class that provides the highest matching value. Reuse of functional primitives in different classes enables easy expansion to new categories. We tested the proposed scheme on a database of about 1000 different 3D objects. The proposed scheme achieved high classification accuracy while using small training sets.

Adaptation for Hierarchical Components and Services

Software coordination and adaptation are tightly related to modular software entities and access points. These entities (components or services) may be complex, dissimilar (various models) and designed at different granularity levels. In order to allow interoperability we need rich interface descriptions including service hierarchisation, flexible declarations and precise specifications. In this article we present a Hierarchical Behavioural interface description language that enables the structuring of services, their encapsulation and it also facilitates the use of component interfaces. We also investigate in this work the adaptation for Hierarchical Behavioural IDL. We recall various adaptation problems and we introduce modelling techniques and some solutions within hierarchical context considering precision of the interfaces, their layering and flexibility.

Veranschaulichung der Lehrstoffstruktur durch Galois-Graphen

In this article we compare the process diagram with the Galois-graph, the two hierarchical descriptions of the curriculum’s construction from the point of didactics. We present the concrete example through the structure of convex quadrangles. As a result of the analysis it is proved that the process diagram is suitable for describing the activity of pupils, still the Galois-graph is the adequate model of the net of knowledge. The analysis also points out that in teaching of convex quadrangles the constructions of curriculum based only on property of symmetry and only on metrical property are coherent. Generalizing concept is prosperous if the pupils’ existing net of knowledge lives on, at most it is amplified and completed. Teaching of convex quadrangles in Hungarian education adopts this principle.

Bond electron pair: Its relevance and analysis from the quantum chemistry point of view

This paper first comments on the surprisingly poor status that Quantum Chemistry has offered to the fantastic intuition of Lewis concerning the distribution of the electrons in the molecule. Then, it advocates in favor of a hierarchical description of the molecular wave-function, distinguishing the physics taking place in the valence space (in the bond and between the bonds), and the dynamical correlation effects. It is argued that the clearest pictures of the valence electronic population combine two localized views, namely the bond (and lone pair) Molecular Orbitals and the Valence Bond decomposition of the wave-function, preferably in the orthogonal version directly accessible from the complete active space self consistent field method. Such a reading of the wave function enables one to understand the work of the nondynamical correlation as an enhancement of the weight of the low-energy VB components, i.e. as a better compromise between the electronic delocalization and the energetic preferences of the atoms. It is suggested that regarding the bond building, the leading dynamical correlation effect may be the dynamical polarization phenomenon. It is shown that most correlation effects do not destroy the bond electron pairs and remain compatible with Lewis' vision. A certain number of free epistemological considerations have been introduced in the development of the argument.

A Hierarchical Presentation of Operators with Fixed Points on Hilbert Spaces

For problems that are aimed at obtaining a common fixed point of a countable class (T i ) i∈I of operators by an iterative procedure, usually an important role is played by an inequality that expresses the behavior of the distances of the original points x and their images T i x to the common fixed point set. The different inequalities that have appeared in the literature seem to impose a classification of the operators in two types; we propose a hierarchical description of the classes belonging to each type, based on some non-negative parameter. This hierarchical presentation makes it easier to investigate (existing or new) results concerning iterative procedures with respect to the possibility of broadening their scope of applicability.

Procedural modeling of buildings

CGA shape , a novel shape grammar for the procedural modeling of CG architecture, produces building shells with high visual quality and geometric detail. It produces extensive architectural models for computer games and movies, at low cost. Context sensitive shape rules allow the user to specify interactions between the entities of the hierarchical shape descriptions. Selected examples demonstrate solutions to previously unsolved modeling problems, especially to consistent mass modeling with volumetric shapes of arbitrary orientation. CGA shape is shown to efficiently generate massive urban models with unprecedented level of detail, with the virtual rebuilding of the archaeological site of Pompeii as a case in point.

A simple framework for spatio-temporal video segmentation and delayering using dense motion fields

To represent object movement, the conventional approach is to embed the motion information into parametric and/or statistical motion models. However, the inherent complexity of this description is ill suited for application requiring rapid and automatic, albeit significant, responses. Surveillance applications belong to this class and are emerging as the most active field of research in computer vision. For this purpose, we observe that the differential invariants obtained by dense optic flow are capable of accurately describing complex object motion without requiring setting up and initializing models. In this letter, we demonstrate the novel use of such motion descriptors for spatio-temporal object segmentation and delayering of sequences. Our results show the ability of this approach to describe simply and accurately differently moving objects and to be incorporated in segmentation processes that deliver a hierarchical description of object, producing evident improvements to the segmented objects while being computationally efficient

Primary grassland communities of urban open spaces in Gauteng, South Africa

A vegetation survey of natural grasslands was undertaken in the urban areas of Gauteng, supporting about 20% of the country's population. Relevés were compiled in 132 sample plots placed in selected open spaces in the study area. A floristic–sociological classification revealed eight grassland communities, represented by 59 relevés. A hierarchical classification, description and ecological interpretation of these plant communities are presented.

Compositional modeling and refinement for hierarchical hybrid systems

In this paper, we develop a theory of modular design and refinement of hierarchical hybrid systems. In particular, we present compositional trace-based semantics for the language C haron that allows modular specification of interacting hybrid systems. For hierarchical description of the system architecture, C haron supports building complex agents via the operations of instantiation, hiding, and parallel composition. For hierarchical description of the behavior of atomic components, C haron supports building complex modes via the operations of instantiation, scoping, and encapsulation. We develop an observational trace semantics for agents as well as for modes, and define a notion of refinement for both, based on trace inclusion. We show this semantics to be compositional with respect to the constructs in the language.

Provably-correct hardware compilation tools based on pass separation techniques

Abstract This paper presents a framework for verifying compilation tools for parametrised hardware designs with placement information. The framework involves Pebble, a simple declarative language based on Structural VHDL which supports the use of placement information to guide circuit layout; such information often leads to efficient designs that are particularly important for hardware libraries. Relative placement information enables control of circuit layout at a higher level of abstraction than placement information in the form of explicit coordinates. An approach based on pass separation techniques is adopted for specifying and verifying two Pebble abstraction mechanisms: a flattening procedure and a relative placement method. For the flattening procedure, which takes a set of parametrised blocks and unfolds the circuit description into a netlist, we provide semantic descriptions of both the hierarchical and the flattened Pebble languages to prove its functional correctness. For the relative placement method, we specify the compilation procedure from Pebble programs with relative placement information to Pebble programs with explicit coordinate expressions, often in the form of symbolic placement constraints. This compilation procedure can be used in conjunction with partial evaluation to optimise the size and speed of parametrised circuit descriptions using relative placement, without flattening the original hierarchical descriptions. Our approach has been used for optimising a pattern matcher design, which results in a 33% reduction in resource usage. For DES encryption, our method can reduce the size of a DES design by 60%.