Structural Aspects of Organizations

2009 ◽  
pp. 190-219 ◽  
Author(s):  
Davide Grossi ◽  
Frank Dignum
Keyword(s):  
Graph Theory ◽  
Description Logic ◽  
Formal Semantics ◽  
Different Dimensions ◽  
Structural Aspects

In this chapter we investigate how organizations can be represented as graphs endowed with formal semantics. We distinguish different dimensions of organizations. Each of these dimensions leads to a different structure in the organizational graph. By giving the graphs a formal semantics in Description Logic we show that it is possible to formalize the effect of the organization on the activities of the agents playing the roles of the organization. Such perspective, which combines quantitative (graph-theory) and qualitative (logic) methods is shown to provide a formal ground for the study and analysis of properties of organizations which are commonly addressed only informally.

scholarly journals Distributed Fuzzy Adaptive Control for Heterogeneous Nonlinear Multiagent Systems with Similar Composite Structure

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yongqing Fan ◽  
Tiantian Xiao ◽  
Zhen Li
Keyword(s):  
Adaptive Control ◽  
Graph Theory ◽  
Multiagent Systems ◽  
Lyapunov Stability ◽  
Closed Loop ◽  
Zero Set ◽  
Closed Loop System ◽  
Fuzzy Adaptive Control ◽  
Different Dimensions ◽  
Fuzzy Adaptive

A distributed fuzzy adaptive control with similar parameters is constructed for a class of heterogeneous multiagent systems. Unlike many existing works, the dimensions of each multiagent dynamic system are considered to be nonidentical in this paper. Firstly, similar properties for different dimensions of multiagent systems are introduced, and some similar parameters among multiagent systems are also proposed. Secondly, a distributed fuzzy adaptive control on the basis of similar parameters is designed for the consensus of leader-follower multiagent systems. Following the graph theory and Lyapunov stability approach, it is concluded that UUB (uniformly ultimately bounded) of all signals in the closed-loop system can be guaranteed, and the consensus tacking error converges to a small compact zero set. Finally, a simulation example with different dimensions is provided to illustrate the effectiveness of the proposed method.

Rule-Based OWL Ontology Reasoning Systems

2010 ◽  
pp. 124-148 ◽  
Author(s):  
Georgios Meditskos ◽  
Nick Bassiliades
Keyword(s):  
Semantic Web ◽  
Description Logic ◽  
Formal Semantics ◽  
Web Ontology Language ◽  
Rule Engine ◽  
Basic Principles ◽  
Rule Based ◽  
Ontology Language ◽  
Open Nature ◽  
The Web

This chapter is focused on the basic principles behind the utilization of rules in order to perform reasoning about the Web Ontology Language (OWL), a Description Logic-based language that is the W3C recommendation for creating and sharing ontologies in the Semantic Web. More precisely, we elaborate on the entailment-based OWL reasoning (EBOR) paradigm, which is based on the utilization of RDF/ RDFS and OWL entailment rules that run on a rule engine, applying the formal semantics of the ontology language. To this end, seven EBOR systems are described and compared, analyzing the different approaches. Despite the closed rule environment, which comes in contrast with the open nature of the Semantic Web, and the fact that OWL semantics are partially mapped into rules, the rule-based OWL reasoning paradigm can give great potentials in the Semantic Web, enabling the utilization of rule engines on top of ontology information.

scholarly journals RESEARCH OF GENETIC ALGORITHMS FOR SEARCHING OPTIMAL WAYS IN THE SYSTEM OF CONDUCTING METROMARATHONS

2019 ◽  
Vol 2 (93) ◽  
pp. 53-58
Author(s):  
О. О. Mazurova ◽  
Т. О. Gordienko
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Experimental Study ◽  
Genetic Algorithms ◽  
Graph Theory ◽  
Different Dimensions ◽  
Subway Stations ◽  
Genome Representation

The work is devoted to the study of genetic algorithms on the example of the search for the best ways to support“Transit challenge” or “Subway Challenge” system. Based on the rules of “Transit challenge” and the tasks of thesalesman, the problem of stations was formulated - the search for the best way to visit all subway stations in the shortestpossible time. Based on the graph theory, a mathematical model of the metrophone system was developed. To solve thestation problem, a genetic algorithm has been developed: the method of genome representation, population mutationand genome crossing rules have been chosen. On the basis of the experimental study of the genetic algorithm the mosteffective parameters were selected and recommendations on the solution of the station problem for “Transit challenge”of different dimensions were developed.

scholarly journals Configuration knowledge representations for Semantic Web applications

2003 ◽  
Vol 17 (1) ◽  
pp. 31-50 ◽  
Author(s):  
ALEXANDER FELFERNIG ◽  
GERHARD FRIEDRICH ◽  
DIETMAR JANNACH ◽  
MARKUS STUMPTNER ◽  
MARKUS ZANKER
Keyword(s):  
Problem Solving ◽  
Semantic Web ◽  
Knowledge Representation ◽  
Web Applications ◽  
Description Logic ◽  
Predicate Logic ◽  
Description Logics ◽  
Formal Semantics ◽  
Problem Definition ◽  
Configuration Problem

Today's economy exhibits a growing trend toward highly specialized solution providers cooperatively offering configurable products and services to their customers. This paradigm shift requires the extension of current standalone configuration technology with capabilities of knowledge sharing and distributed problem solving. In this context a standardized configuration knowledge representation language with formal semantics is needed in order to support knowledge interchange between different configuration environments. Languages such as Ontology Inference Layer (OIL) and DARPA Agent Markup Language (DAML+OIL) are based on such formal semantics (description logic) and are very popular for knowledge representation in the Semantic Web. In this paper we analyze the applicability of those languages with respect to configuration knowledge representation and discuss additional demands on expressivity. For joint configuration problem solving it is necessary to agree on a common problem definition. Therefore, we give a description logic based definition of a configuration problem and show its equivalence with existing consistency-based definitions, thus joining the two major streams in knowledge-based configuration (description logics and predicate logic/constraint based configuration).

ONTOLOGY-BASED SEMANTIC VERIFICATION FOR UML BEHAVIORAL MODELS

2013 ◽  
Vol 23 (02) ◽  
pp. 117-145 ◽  
Author(s):  
HONGYUE HE ◽  
ZHIXUE WANG ◽  
QINGCHAO DONG ◽  
WEIZHONG ZHANG ◽  
WEIXING ZHU
Keyword(s):  
Description Logic ◽  
System Analysis ◽  
Formal Semantics ◽  
Behavioral Model ◽  
Model Verification ◽  
Behavioral Models ◽  
Analysis And Design ◽  
Requirements Modeling ◽  
Logic System

UML is now popularly applied as a requirements modeling language for software system analysis and design, and the dynamic behaviors of system are described in UML behavioral model. As the UML model suffers from lack of well-defined formal semantics, it is difficult to formally analyze and verify the behavioral model. The paper presents a method of UML behavioral model verification based on Description Logic system and its formal inference. The semantics of UML behavioral models is divided into static semantics and dynamic semantics, which are formally specified in OWL DL ontology and DL-Safe rules. To check the consistency of the behavioral models, the algorithms are provided for transforming UML behavioral models into OWL DL ontology, and hence model consistency can be verified through formal reasoning with a DL supporting reasoner Pellet. A case study is provided to demonstrate applicability of the method.

Structural aspects of osmoregulation in porphyra

1978 ◽  
Vol 36 (2) ◽  
pp. 412-413
Author(s):  
C. Wiencke ◽  
A. Lauchli
Keyword(s):  
Culture Medium ◽  
Point Of View ◽  
Chemical Fixation ◽  
Cellular Organization ◽  
Osmotic Adaptation ◽  
Osmotic Balance ◽  
Activity Of Enzymes ◽  
Osmotic Agents ◽  
Vacuolar System ◽  
Structural Aspects

Osmoregulatory mechanisms in algae were investigated mainly from a physiological point of view (KAUSS 1977, HELLEBUST 1976). In Porphyra two osmotic agents, i. e. floridoside/isofloridoside (KAUSS 1968) and certain ions, such as K+ and Na+(EPPLEY et al. 1960) are considered for osmotic balance. Accumulations of ions (particularly Na+) in the cytoplasm during osmotic adaptation is improbable, because the activity of enzymes is generally inhibited by high ionic concentrations (FLOWERS et al. 1977).The cellular organization of Porphyra was studied with special emphasis on the development of the vacuolar system under different hyperosmotic conditions. Porphyra was cultivated at various strengths of the culture medium ASP 12 (PROVASOLI 1961) ranging from normal to 6 times concentrated (6x) culture medium. Por electron microscopy freeze fracturing was used (specimens fixed in 2% glutaraldehyde and incubated in 30% glycerol, preparation in a BALZERS BA 360 M apparatus), because chemical fixation gave poor results.

Molecular Structure of the Outermost Cell Wall Component of Spirillum Serpens

1977 ◽  
Vol 35 ◽  
pp. 342-343
Author(s):  
Wah Chiu ◽  
David Grano
Keyword(s):  
Molecular Structure ◽  
Cell Wall ◽  
Outer Membrane ◽  
Gel Electrophoresis ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Cell Wall Component ◽  
Protein Components ◽  
Exposure Technique ◽  
Structural Aspects

The periodic structure external to the outer membrane of Spirillum serpens VHA has been isolated by similar procedures to those used by Buckmire and Murray (1). From SDS gel electrophoresis, we have found that the isolated fragments contain several protein components, and that the crystalline structure is composed of a glycoprotein component with a molecular weight of ∽ 140,000 daltons (2). Under an electron microscopic examination, we have visualized the hexagonally-packed glycoprotein subunits, as well as the bilayer profile of the outer membrane. In this paper, we will discuss some structural aspects of the crystalline glycoproteins, based on computer-reconstructed images of the external cell wall fragments.The specimens were prepared for electron microscopy in two ways: negatively stained with 1% PTA, and maintained in a frozen-hydrated state (3). The micrographs were taken with a JEM-100B electron microscope with a field emission gun. The minimum exposure technique was essential for imaging the frozen- hydrated specimens.

Biogenesis of Catalase-Positive Rods in Excretory Duct Cells of Salivary Glands

1976 ◽  
Vol 34 ◽  
pp. 62-63
Author(s):  
Dwight K. Romanovicz ◽  
Jacob S. Hanker
Keyword(s):  
Light Microscopy ◽  
Salivary Glands ◽  
Submandibular Gland ◽  
Excretory Duct ◽  
Exocrine Glands ◽  
Duct Cells ◽  
Peroxidatic Activity ◽  
Microscopic Studies ◽  
Different Dimensions

The presence of catalase-positive rods (Fig. 1) of different dimensions, which frequently have a crystalline appearance by light microscopy, has been reported. They seem to be related to peroxisomes which were characterized morphologically and cytochemically in parotid and other exocrine glands of the rat by Hand in 1973. Our light microscopic studies of these spherical microbodies and rods of different sizes, stained by virtue of the peroxidatic activity of their catalase, indicate that they are almost entirely confined to the cells of the striated and execretory ducts of the submandibular gland in the mouse. The rods were usually noted only in the proximity of the ductal microbodies. The latter frequently showed a tendency to appear in linear close array, or even to be contiguous (Fig. 2). This suggested that the rods could be formed by the fusion of microbodies.

7-beam lattice images of (110) oriented Ge

1978 ◽  
Vol 36 (1) ◽  
pp. 290-291
Author(s):  
J.R. Parsons ◽  
C.W. Hoelke
Keyword(s):  
Image Features ◽  
Objective Lens ◽  
Lattice Plane ◽  
Lattice Image ◽  
Crystalline Defects ◽  
Transmission Electron ◽  
Lattice Images ◽  
Electron Microscopes ◽  
Structural Aspects ◽  
Beam Lattice

The direct imaging of a crystal lattice has intrigued electron microscopists for many years. What is of interest, of course, is the way in which defects perturb their atomic regularity. There are problems, however, when one wishes to relate aperiodic image features to structural aspects of crystalline defects. If the defect is inclined to the foil plane and if, as is the case with present 100 kV transmission electron microscopes, the objective lens is not perfect, then terminating fringes and fringe bending seen in the image cannot be related in a simple way to lattice plane geometry in the specimen (1).The purpose of the present work was to devise an experimental test which could be used to confirm, or not, the existence of a one-to-one correspondence between lattice image and specimen structure over the desired range of specimen spacings. Through a study of computed images the following test emerged.

Structural aspects of tracheary element differentiation in suspension cultures of Zinnia elegans

1989 ◽  
Vol 47 ◽  
pp. 768-769
Author(s):  
C. H. Haigler ◽  
A. W. Roberts
Keyword(s):  
Tracheary Element ◽  
Vesicle Fusion ◽  
Zinnia Elegans ◽  
Cellulose Synthesis ◽  
Tracheary Elements ◽  
Animal Cells ◽  
Mesophyll Cells ◽  
Fixation Techniques ◽  
Localized Patterns ◽  
Structural Aspects

Tracheary elements, the water-conducting cells in plants, are characterized by their reinforced walls that became thickened in localized patterns during differentiation (Fig. 1). The synthesis of this localized wall involves abundant secretion of Golgi vesicles that export preformed matrix polysaccharides and putative proteins involved in cellulose synthesis. Since the cells are not growing, some kind of endocytotic process must also occur. Many researchers have commented on where exocytosis occurs in relation to the thickenings (for example, see), but they based their interpretations on chemical fixation techniques that are not likely to provide reliable information about rapid processes such as vesicle fusion. We have used rapid freezing to more accurately assess patterns of vesicle fusion in tracheary elements. We have also determined the localization of calcium, which is known to regulate vesicle fusion in plant and animal cells.Mesophyll cells were obtained from immature first leaves of Zinnia elegans var. Envy (Park Seed Co., Greenwood, S.C.) and cultured as described previously with the following exceptions: (a) concentration of benzylaminopurine in the culture medium was reduced to 0.2 mg/l and myoinositol was eliminated; and (b) 1.75ml cultures were incubated in 22 x 90mm shell vials with 112rpm rotary shaking. Cells that were actively involved in differentiation were harvested and frozen in solidifying Freon as described previously. Fractures occurred preferentially at the cell/planchet interface, which allowed us to find some excellently-preserved cells in the replicas. Other differentiating cells were incubated for 20-30 min in 10(μM CTC (Sigma), an antibiotic that fluoresces in the presence of membrane-sequestered calcium. They were observed in an Olympus BH-2 microscope equipped for epi-fluorescence (violet filter package and additional Zeiss KP560 barrier filter to block chlorophyll autofluorescence).

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