DIAGNOSTICS OF A GAS TURBINE ENGINE WITH LOCALIZATION OF DEFECTS IN ITS NODES

Drawing up adequate mathematical models of the studied objects for computer-aided design systems is quite difficult. To increase the reliability of a decision made using mathematical models, you can, in particular, by specifying the parameters of the models based on the results of the experiment (identification). There are a number of identification, methods that differ by the adequacy criterion is using and is basing on different a priori information. When choosing the identification method, it is necessary to take into account the complexity of obtaining sufficiently complete experimental information during tests. Due to the lack of information in the identification process, there is objectively a whole range of possible solutions (a set of combinations of values of variable parameters) with an acceptable value of the adequacy criterion. Finding the minimum is a computationally difficult task (very elongated "gullies"), but a more serious problem is that the solution is potentially unstable relative to the features of the experimental data (the position of the minimum can shift markedly with a small change in the original data). In this case, it is necessary to use special mathematical methods for solving such incorrect problems, which allow us to obtain stable estimates of variable parameters. Analysis of the methods has shown the feasibility of using the method of ridge estimates with certain improvements. Experience with the program has confirmed that the method works. Preliminary processing of the received information carried out by excluding gross measurement errors and bringing the measured parameters to the same flight conditions and to the same mode. In most methods, the measured parameters adjusted to standard atmospheric conditions using the average throttle characteristics obtained during bench tests of several engines of this series.

Allowance for capacity adequacy criterion in optimizing the prospective structure of electric power system

This paper considers the optimization procedure of electric power system prospective structure with account made for two criteria: economic value (minimization of specific reduced energy costs for customers) and capacity adequacy (minimization of capacity shortage probability). The proposed procedure is based on genetic algorithm application. The results of procedure evaluation have been considered by the example of optimization of the structure of generating capacities within concentrated power system.

Model-based estimation of radio parameters

It’s proposed to use model-based approach for evaluation of radiation parameters observed by passive location facilities. This method is based on model parameters adjustment and interpretation of correspondent parameters values as experimental parameters evaluations. Evaluation adequacy criterion in this case is maximal probability of overlapping of experimental and model ranges of parameters. Preliminary objects selection can be based on frequency or/end directional characteristics of received signals. A possible selection criterion is based on discrimination conditions of frequency and time ranges. The appropriate analysis is performed on the basis of the extremal analysis enabling to select ranges corresponding to observed objects. Selected ranges are transformed into time functions to be analyzed by model-based method. Therewith the frequency analysis is performed on the assumption of linear frequency modulation of the signal observed. In its turn, the amplitude analysis is based on the passive location model. Parameters are selected either by Monte-Carlo method or by direct processing of equidistant grid nodes.

A Multi-Agent-Based Approach for Critical Components Identification and Testing

In real time software systems, testing plays a crucial role as any of the critical components in these systems are left undetected, then inadvertent effects will happen which will lead to erroneous operations, system failure, high cost and resource wastage etc. To address this most important and the emergent problem, this research work proposes an effective method by means of multi-agents based approach to identify such critical components and execute test cases along the critical test paths which will aid in effectively covering them during testing. Finally, this paper also compared the performance with existing approaches in terms of time taken for the search process and the component coverage based test adequacy criterion to ensure quality of the software.

Research on Testing Adequacy Criterion of Reactor Physics Code of NESTOR

In view of the characteristics of the physical code Nestor the focus is on the correctness of calculation for which the test adequacy criterion has been established. This is based on structural coverage and the input domain. According to such test adequacy criterion, testing strategies have been applied on the entire testing process. They consist of unit static, unit dynamic, integration, system and regression test strategy. Each strategy is composed of test target, test range, technology and method, entry criterion, completion criterion, test focus and priority. After compared with 11 basic benchmarks from nuclear power plants and calculation result of benchmark programs, the ELEMENT program result is correct and credible; the relative error of result is less than three percent. The ELEMENT testing is adequacy. Its test cases covers fuel grid element types, fuel types, non-combustible grid element types, and control rod computational models. Furthermore, it puts forward a research direction in the future.

Learners’ Perspective on the Situation of Bed Side Teaching on the Medical Floor in a Tertiary Care Teaching Hospital

<p><strong>Objective:</strong> Decline in bedside teaching is one of the problems that medical education is facing today. It has always been the best modality for effectively imparting clinical skills. It has declined from 75% in 1960s to 8 – 19% today. Various factors notably advancing medical technology are in essence phasing out bedside teaching. Our study was aimed to assess frequency and adequacy of bedside teaching on the medical floor.</p><p><strong>Methods:</strong><strong> </strong>This cross sectional study conducted in May 2015 in Mayo Hospital, Lahore included 152 trainee doctors, who gave feedback about various aspects of bedside teaching via a self-administered questionnaire. Frequency of bedside teaching was assessed in terms of number of sessions per week. It was considered adequate if its various aspects including contributions by teachers, learners, allied health professionals and patients were carried out in 70% or more sessions. Z-test was used to compare these aspects to the adequacy criterion. Responses of house officers and postgraduates and male and female doctors were compared by t-test. P-value &lt; 0.05 was considered significant.</p><p><strong>Results:</strong><strong> </strong>Frequency of bedside teaching was reported to be 62.25%. All aspects of bedside teaching were significantly lower than the adequacy criterion (p-value 0.000). The inadequacy was more noticeable by postgraduates (p-value &lt; 0.05).</p><p><strong>Conclusion:</strong><strong> </strong>Frequency of bedside teaching was acceptable but the adequacy criterion was not achieved in any of the areas studied.</p>