Zdenka Prokopova

Algorithmic Optimisation Method for Improving Use Case Points Estimation

This paper presents a new size estimation method that can be used to estimate size level for software engineering projects. The Algorithmic Optimisation Method is based on Use Case Points and on Multiple Least Square Regression. The method is derived into three phases. The first phase deals with calculation Use Case Points and correction coefficients values. Correction coefficients are obtained by using Multiple Least Square Regression. New project is estimated in the second and third phase. In the second phase Use Case Points parameters for new estimation are set up and in the third phase project estimation is performed. Final estimation is obtained by using newly developed estimation equation, which used two correction coefficients. The Algorithmic Optimisation Method performs approximately 43% better than the Use Case Points method, based on their magnitude of relative error score. All results were evaluated by standard approach: visual inspection, goodness of fit measure and statistical significance.

Modern Trends and Techniques in Computer Science

This book is based on the research papers presented in the 3rd Computer Science On-line Conference 2014 (CSOC 2014).The conference is intended to provide an international forum for discussions on the latest high-quality research results in all areas related to Computer Science. The topics addressed are the theoretical aspects and applications of Artificial Intelligences, Computer Science, Informatics and Software Engineering. The authors provide new approaches and methods to real-world problems, and in particular, exploratory research that describes novel approaches in their field. Particular emphasis is laid on modern trends in selected fields of interest. New algorithms or methods in a variety of fields are also presented. This book is divided into three sections and covers topics including Artificial Intelligence, Computer Science and Software Engineering. Each section consists of new theoretical contributions and applications which can be used for the further development of knowledge of everybody who is looking for new knowledge or new inspiration for further research.

Evaluating subset selection methods for use case points estimation

Abstract When the Use Case Points method is used for software effort estimation, users are faced with low model accuracy which impacts on its practical application. This study investigates the significance of using subset selection methods for the prediction accuracy of Multiple Linear Regression models, obtained by the stepwise approach. K-means, Spectral Clustering, the Gaussian Mixture Model and Moving Window are evaluated as appropriate subset selection techniques. The methods were evaluated according to several evaluation criteria and then statistically tested. Evaluation was performing on two independent datasets - which differ in project types and size. Both were cut by the hold-out method. If clustering were used, the training sets were clustered into 3 classes; and, for each of class, an independent regression model was created. These were later used for the prediction of testing sets. If Moving Window was used, then window of sizes 5, 10 and 15 were tested. The results show that clustering techniques decrease prediction errors significantly when compared to Use Case Points or moving windows methods. Spectral Clustering was selected as the best-performing solution, because it achieves a Sum of Squared Errors reduction of 32% for the first dataset, and 98% for the second dataset. The Mean Absolute Percentage Error is less than 1% for the second dataset for Spectral Clustering; 9% for moving window; and 27% for Use Case Points. When the first dataset is used, then prediction errors are significantly higher – 53% for Spectral Clustering, but Use Case Points produces a 165% result. It can be concluded that this study proves subset selection techniques as a significant method for improving the prediction ability of linear regression models - which are used for software development effort prediction. It can also be concluded that the clustering method performs better than the moving window method.

Robust Tuning of PID-Like Controllers

Abstract The contribution is focused on robust design and analysis of continuous-time controllers for SISO systems without and with time delays. Controllers are obtained via solutions of diophantine equations in the ring of proper and stable rational functions. Uncertainty is studied through the infinity norm H ∞ . A scalar parameter was proposed as a tuning knob for minimization of the sensitivity function and uncertainty evaluation. A Matlab-Simulink package was developed for design and simulation of proposed algorithms.

Web-based service portal in healthcare

Information delivery is one the most important task in healthcare. The growing sector of electronic healthcare has an important impact on the information delivery. There are two basic approaches towards information delivering. The first is web portal and second is touch-screen terminal. The aim of this paper is to investigate the web-based service portal. The most important advantage of web-based portal in the field of healthcare is an independent access for patients. This paper deals with the conditions and frameworks for healthcare portals

Design of Robust Controllers for Time-Delay Systems

Abstract A method of controller design and tuning for SISO continuous-time processes with dead-time is proposed. The control synthesis is based on solutions of Diophantine equations in a ring of Hurwitz stable and proper rational functions. The proposed methodology covers stable and unstable plants with dead-time. A scalar tuning parameter which influences properties of the closed loop system is introduced. The robust stabilization of control systems is studied through the infinity norm of transfer functions.

Software Engineering in Intelligent Systems

This volume is based on the research papers presented in the 4th Computer Science On-line Conference. The volume Software Engineering in Intelligent Systems presents new approaches and methods to real-world problems, and in particular, exploratory research that describes novel approaches in the field of Software Engineering. Particular emphasis is laid on modern trends in selected fields of interest. New algorithms or methods in a variety of fields are also presented. The Computer Science On-line Conference (CSOC 2015) is intended to provide an international forum for discussions on the latest high-quality research results in all areas related to Computer Science. The addressed topics are the theoretical aspects and applications of Computer Science, Artificial Intelligences, Cybernetics, Automation Control Theory and Software Engineering.

Using Analytical Programming and UCP Method for Effort Estimation

This article is aimed to using the analytical programming and the Use Case Points method to estimate time effort in software engineering. The calculation of Use Case Points method is strictly algorithmically defined, and the calculation of this method is simple and fast. Despite a lot of research on this field, there are many attempts to calibrating the weights of Use Case Points method. In this paper is described idea that equation used in Use Case Points method could be less accurate in estimation than other equations. The aim of this research is to create new method, that will be able to create new equations for Use Case Points method. Analytical programming with self-organizing migration algorithm is used for this task. The experimental results shows that this method improving accuracy of effort estimation by 25–40 %.

Patients’ Perspective of the Design of Provider-Patients Electronic Communication Services

Information Delivery is one the most important tasks in healthcare practice. This article discusses patient’s tasks and perspectives, which are then used to design a new Effective Electronic Methodology. The system design methods applicable to electronic communication in the healthcare sector are also described. The architecture and the methodology for the healthcare service portal are set out in the proposed system design.

Relay Feedback Autotuning - A Polynomial Design Approach.

A method of autotuning using an asymmetric relay with hysteresis feedback test is proposed and developed. Then, three parameters for aperiodic first or second order transfer functions can be obtained. After the identification relay experiment, controller parameters are computed through linear diophantine equation in the ring of proper and stable rational functions. This algebraic approach for a traditional 1-DOF feedback structure generates a class of PI or PID controllers. The pole placement principle in the methodology brings a scalar positive “tuning knob” for additional controller tuning. A Matlab-Simulink program implementation was developed for simulation and verification of the studied approach. Two illustrative examples support simplicity and efficiency of the proposed methodology. INTRODUCTION Despite of expressive evolution of control hardware, PID controllers remain the main tool in industrial feedback loops and they survived many changes in technology. The practical advantages of PID controllers can be seen in a simple structure, in an understandable principle and in control capabilities. It is widely known that PID controllers are quite resistant to changes in the controlled process without meaningful deterioration of the loop behavior. However, real industrial processes suffer from many unpleasant drawbacks as non-linearity, complexity and time variance. These features induce difficulties to control their loops properly. Adequate and sufficient tuning of controllers needs to know relevant process parameters. One way how to overcome the mentioned problems consists in automatic tuning of controllers. The development of various autotuning principles was started by a simple symmetrical relay feedback experiment (Astrom and Hagglund 1984) for a PID structure. Ultimate gain and ultimate frequency are then used for adjusting of parameters by common known Ziegler-Nichols rules. During the period of more than two decades, many studies have been reported to extend and improve autotuners principles; see e.g. (Astrom and Hagglund 1995; Ingimundarson and Hagglund 2000; Majhi and Atherton 1998; Morilla at al. 2000). The extension in an experimental phase was performed in (Yu 1999; Pecharroman and Pagola 2000; Kaya and Atherton 2001) by an asymmetry and hysteresis of a relay, see (Thyagarajan and Yu 2002), and experiments with asymmetrical and dead-zone relay feedback are reported in (Viteckova and Vitecek 2004; Vyhlidal 2000). Also, various control design principles and rules can be investigated in mentioned references. Nowadays, almost all commercial industrial PID controllers provide the feature of autotuning. This paper is focused on a novel combination for autotunig method of PI and PID controllers. The method combines an asymmetrical relay identification experiment and a control design which is based on a pole-placement principle. The pole placement problem is formulated through a Diophantine equation and it is tuned by an equalization setting proposed in (Gorez and Klan 2000). PROCESS PARAMETERS IDENTIFICATION System identification of the process parameters is a crucial point for many auto-tuning principles. The identification rules with relay in feedback loops can utilize various types of relays. The relay feedback proposed by Astrom in 1984 used a symmetrical relay without hysteresis. The identification procedure with a relay in the feedback loop can utilize various types of relays. The relay feedback proposed by Astrom in 1984 utilizes symmetrical relay without hysteresis. This procedure gives the ultimate parameters of the process and control design may follow. Unfortunately, the process gain must be known in advance because the symmetrical relay test cannot identify it. On the other hand, the process gain can be obtained during the relay feedback test when an asymmetrical relay is utilized. A typical data response from the relay experiment can be seen in Figure 1. In this paper, an asymmetric relay with hysteresis is used. It enables to identify the parameters of the transfer function, such as proportional gain, time constant, as well as time delay term. Time delay is approximated by Pade approximation before the algebraic controller design. Proceedings 24th European Conference on Modelling and Simulation ©ECMS Andrzej Bargiela, Sayed Azam Ali David Crowley, Eugene J.H. Kerckhoffs (Editors) ISBN: 978-0-9564944-0-5 / ISBN: 978-0-9564944-1-2 (CD) 0 5 10 15 20 25 30 35 40 45 50 -0.2 -0.1 0 0.1 0.2 0.3 Figure 1: Relay feedback test of stable process First order system The most popular and simplest approximation of aperiodic industrial processes can be characterized by the first order transfer function with time delay (FOPDT) in the form: Ls e Ts K s G − ⋅ + = 1 ) ( (1) When the asymmetric relay is used for the relay feedback test, it is shown in Figure 1, the output y converges to the stationary oscillation in one period. These oscillations are characterized by equations (Hang et al. 2001):