2003, VOLUME 4 #2. "TRANSPORT AND TELECOMMUNICATION". SCIENTIFIC & RESEARCH JOURNAL OF TTI, ISSN 1407-6160
Transport and Telecommunications are two global technologies that play the leading role in the world today. The creation of the unique European transport area is ensured by their development in the considerable degree. Our edition is one more afford on the way of speeding up of this process.
The aim of the journal is to acquaint the reader with the national experience of various countries in the fields of transport and telematics applied researches as well as with the working materials of the European thematic networks and the research projects in this area.
We hope that our edition will be interesting to the wide range of the researchers, academics and professionals, and we invite all interested persons to take part in the forming of its information politics.
This special edition is devoted to the International Conference "Reliability and Statistics in Transportation and Communication" (October 17-18, 2002, Riga, Latvia. Host organization - Transport and Telecommunication Institute). The edition includes texts of conference reports written by the authors in a special journal version.
The authors have submitted the material in the English or Russian in accordance with the official languages of the Conference. Therefore, for the convenience of readers the editorial board has divided the selected materials into two editions - English (Vol.4, N2, 2003) and Russian (Vol.4, N1, 2003).
- Title List and Editorial Board
- Editorial Notes
- Programme Of The International Conference "Reliability and Statistics in Transportation and Communication (RelStat'02)" 17-18 october 2002. Riga, Latvia
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The importance of forecasting the economic characteristics of transportation (i.e. the amount of freight and passengers carried, the turnover rate of freight and passengers, etc. in transportation as a whole and in particular areas using various transport facilities) is demonstrated. Methods for predicting the development of transportation based on multidimensional regression and correlation analysis and realizing mathematical models for finding linear and non-linear multidimensional regression equations as well as a mathematical model for choosing linear and non-linear regression equations, more accurately approximating the empirical data, are presented.
The techniques aimed to obtain and apply the linear correlation coefficient and correlative relationship in determining the forecast accuracy is also given. The efficiency of methods, determining the linear correlation coefficient and correlative relationship, used in achieving higher accuracy of forecasts is shown.
Modeling many problems of mathematical physics, economy, statistics, actuary mathematics and etc., frequently we obtain operational equations of the first kind. As a rule, these equations concern to ill-posed problems. There are some iterative methods for solution of such problems. In the present work we consider the concrete iterative method and we estimate its degree of convergence without any additional conditions.
Key words: telematics, decision making, data fusion, algorithmic undecidable problem, complexity, fractals
This paper is devoted to the verification of measurable quality goals established to fit both SEI CMM and ISO 9001:2000 standard requirements. On-time product delivery is defined as the company level quality objective. Definition of the goal is done implementing CMM Goal-Driven approach. A set of sub goals required to achieve the main quality goal is developed using the question-goal-metric (QGM) paradigm. Software development life cycle is analyzed, and appropriative quality indicators are determined. Practically accessible information for the selected quality management model is evaluated. A possibility of process trends recognition based on the actually collected data is analyzed. Examples of real software process trends regarding the quality goal achievement are presented. The area of applicability for the reviewed solution is discussed.
Key words: CMM, ISO 9001:2000, quality goals, measurements, software engineering processes
Key words: fatigue, scale, statistical factor, model
The resource estimation problem of object-oriented development at an early stage of the program project has the large value and a urgency in modern software engineering. This article describes a FP based strategy offered for solution of this problem.
Key words: Function Point Analysis, Use Case model, resource estimation
In this paper, for identifying an observable system with one of several simulation models, a uniformly most powerful invariant (UMPI) test is developed from the generalized maximum likelihood ratio (GMLR). This test can be considered as a result of a new approach to solving the Behrens-Fisher problem when covariance matrices of two multivariate normal populations (compared with respect to their means) are different and unknown. The test is based on invariant statistic whose distribution, under the null hypothesis, does not depend on the unknown (nuisance) parameters.
This paper describes a technique for detecting departures from constancy of regression relationships over time when regression analysis is applied to time-series data. The problem we consider is a special case of a general class of problems concerned with the detection of changes of model structure over time. The technique proposed here for solving the above problem is based on transforming a set of random variables into a smaller set of random variables that are independently distributed with parameter-free distributions. It allows one to eliminate unknown parameters from the problem and is especially efficient when we deal with small samples of the data. A numerical example is given.
Key words: Switching regression, Segmented regression, Change-points, Detection
This paper was written during the work in Department of Infrastructure and Planning and was supported by the Royal Institute of Technology, Stockholm, Sweden. I am grateful to professor Folke Snickars and to Uno Danielsson from the Swedish National Road Administration for presentation of the problem, to Lars-Göran Mattsson for fruitful suggestions and all of them for helpful discussions. I am also grateful to Stephen Fournier for help in preparing this paper and for computer support.
The objective of this paper is to focus attention on a new practicable statistical approach to goodness-of-fit testing which is based on the notion of sufficiency and provides a unified efficient approach to the problem of test construction in the presence of nuisance parameters. The general strategy of the above approach is to transform a set of random variables into a smaller set of independently and identically distributed uniform random variables on the interval (0,1) under the null hypothesis H0. Under the alternative hypothesis this set of rv's will, in general, not be i.i.d. U(0,1). In other words, we replace the composite hypotheses by equivalent simple ones. Any statistic that measures a distance from uniformity in the transformed sample can be used as a test statistic. For instance, for this situation standard procedures of goodness-of-fit testing such as those based on Kolmogorov-Smirnov and Cramér-von Mises statistics can be used. The obtained results are applicable to model selection.
Key words: Characterization theorems, Small sample, Goodness-of-fit testing
Key words: fatigue crack, reliability, aircraft inspection program, Monte-Carlo modelling
In the process of determining the worth of equipment to perform a given task the engineer is often primarily concerned with three quantities: reliability, maintainability, and availability, A. In many instances the most pertinent of the three is the latter. In this paper, the case is considered when the time between failures and the time to repair are independent negative exponential random variables. A new approach to determining the minimum variance unbiased estimator (MVUE) of A that emphasizes pivotal quantities is presented. We consider estimation problems that are invariant under a group of transformation G such that the induced group acts transitively on the parameter space.
Key words: System availability, Minimum variance unbiased estimator, Technique for constructing
Key words: Transport facilities, radio communication reliability, receiving ferrite aerial.
In this paper, we introduce a model that can assist airline planners in deploying their fleets as efficiently as possible. Specifically, we outline an optimization model that assigns a fleet of aircraft of different types to routes to maximize profits. An algorithm for solving nonlinear transportation problem is suggested. It is based on the use of the Lagrange multipliers. We define and illustrate the use of the loss function, the cost structure of which is piecewise linear. The necessary and sufficient conditions for optimality are given.
Key words: Vehicles, Allocation problem, Optimization algorithm.