Search results for "Abstract"

Metamodel Specialization for DSL Tool Building

2016

Most of domain-specific tool building and especially diagram editor building nowadays involves some usage of metamodels. However normally the metamodel alone is not sufficient to define an editor. Frequently the metamodel just defines the abstract syntax of the domain, mappings or transformations are required to define the editor. Another approach [8] is based on a fixed type metamodel, there an editor definition consists of an instance of this metamodel to be executed by an engine. However there typically a number of functionality extensions in a transformation language is required. The paper offers a new approach based on metamodel specialization. First the metamodel specialization based …

An EKF Based Method for Path Following in Turbulent Air

2017

An innovative use of the Extended Kalman Filter (EKF) is proposed to perform both accurate path following and adequate disturbance rejection in turbulent air. The tuned up procedure employs simultaneously two different EKF: the first one estimates gust disturbances, the second one estimates modified aircraft parameters. The first filter, by using measurements gathered in turbulent air, estimates both aircraft states and wind components. The second one, by using the estimated disturbances, obtains command laws that are able to reject disturbances. The predictor of the second EKF uses the estimated wind components to solve motion equations in turbulent air. Besides a set of unknown stability …

An experiment to study the structure of the focal volume in apertured focusing systems

2001

We present a simple experiment, specifically designed for students of undergraduate optics courses, where the influence of an aperture stop position on the three-dimensional structure of the focal volume of focusing systems is studied. The experiment, which involves only simple optical elements, permits an undergraduate student to generate different focal structures by simply axially displacing the aperture stop.

Survey: Intrusion Detection Systems in Encrypted Traffic

2016

Intrusion detection system, IDS, traditionally inspects the payload information of packets. This approach is not valid in encrypted traffic as the payload information is not available. There are two approaches, with different detection capabilities, to overcome the challenges of encryption: traffic decryption or traffic analysis. This paper presents a comprehensive survey of the research related to the IDSs in encrypted traffic. The focus is on traffic analysis, which does not need traffic decryption. One of the major limitations of the surveyed researches is that most of them are concentrating in detecting the same limited type of attacks, such as brute force or scanning attacks. Both the …

The Role of Log Entries in the Quality Control of Video Distribution

2012

Diversification of university teaching with the help of video lectures has become much more common during the past few years. Once videos have become an essential part of teaching arrangements, whoever organizes the teaching must also pay attention to factors related to videos in quality system work for teaching. In the video production process it is the factors related to video transmission that exert influence on the usability of videos and set limitations for their production. A lot of information about those factors can be obtained from the media server log files. The particular focus of this paper is on the functionality of the connection between a server and a client and its effect on…

Prediction of defects using machine learning techniques in order to improve quality management system – A case study

2021

According to ISO 9000, a quality management system is part of a set of related or interacting elements of an organization that sets policies and objectives, as well as the processes necessary to achieve the quality objectives. Quality is the extent to which a set of intrinsic characteristics of an object meets the requirements. Based on these definitions, the factory, considered in this paper, S.C. APULUM S.A.,decided to implement a quality management system since 1998. Subsequently, the organization’s attention is focus on the continuous improvement of the implemented quality management system. The purpose of this paper is to study the percent of specified defects specific to ceramic produ…

Cancellation, pumping and permutation in formal languages

1984

An oscillatory population model

2004

Abstract We consider a simple population model which includes time-dependent parameters prompted by the recent work of Lakshmi [Chaos, Solitons & Fractals 16 (2003) 183]. Time-dependent parameters introduce the possibility of chaos into the dynamics of even simple models. We provide some solutions of the model, compare them with the ones obtained by Lakshmi and discuss their behaviour and properties.

Electronic Shell Structure in Icosahedral Metal Clusters

1992

The shell structure of valence electrons in icosahedral and cuboctahedral simple metal clusters is studied using the free electron model and the Huckel model. The shell structure in a 1415 atom icosahedral cluster has still similarities with that of a spherical cluster. The effect of the finite temperature on the shell structure in liquid clusters is discussed.

Singular factorizations, self-adjoint extensions, and applications to quantum many-body physics

2006

We study self-adjoint operators defined by factorizing second order differential operators in first order ones. We discuss examples where such factorizations introduce singular interactions into simple quantum mechanical models like the harmonic oscillator or the free particle on the circle. The generalization of these examples to the many-body case yields quantum models of distinguishable and interacting particles in one dimensions which can be solved explicitly and by simple means. Our considerations lead us to a simple method to construct exactly solvable quantum many-body systems of Calogero-Sutherland type.