How to reduce the number of rating scale items without predictability loss?

Rating scales are used to elicit data about qualitative entities (e.g., research collaboration). This study presents an innovative method for reducing the number of rating scale items without the predictability loss. The "area under the receiver operator curve method" (AUC ROC) is used. The presented method has reduced the number of rating scale items (variables) to 28.57\% (from 21 to 6) making over 70\% of collected data unnecessary. Results have been verified by two methods of analysis: Graded Response Model (GRM) and Confirmatory Factor Analysis (CFA). GRM revealed that the new method differentiates observations of high and middle scores. CFA proved that the reliability of the rating scale has not deteriorated by the scale item reduction. Both statistical analysis evidenced usefulness of the AUC ROC reduction method.Comment: 14 pages, 5 figure

Prospective Observational Study on acute Appendicitis Worldwide (POSAW)

Acute appendicitis (AA) is the most common surgical disease, and appendectomy is the treatment of choice in the majority of cases. A correct diagnosis is key for decreasing the negative appendectomy rate. The management can become difficult in case of complicated appendicitis. The aim of this study is to describe the worldwide clinical and diagnostic work-up and management of AA in surgical departments.info:eu-repo/semantics/publishedVersio

Non-Extensive Statistical Mechanics - a Possible Basis for Modelling Processes in Computer Memory System

Tsallis definition of non-extensive entropy introduced in 1988 has been considered to obtain new possibilities to construct generalized thermodynamical basis for statistical physics expanding classical Boltzmann-Gibbs thermodynamics for nonequilibrium states. During the last two decades this q-generalized theory has been successfully applied to considerable number of physically interesting complex phenomena. In the paper the possible thermodynamical basis of processes will be presented in nowadays computer systems in the case of memory behaviour

Influence of Long-Term Dependences on Hard Drives Performance during Human Computer Interaction

Today, computer systems become one of the most important systems in technology and our life. They have a plenty of possible applications but most of them can be described as a transformation of (electrical) energy into useful work = calculations. This process is not so simple as it seems to be because the structure of computers hardware is very complicated and processed tasks are also very complex. Because the expectations of computer users are very high, a lot of computer resources are used only for operating systems normal work. Some existing solutions, especially in the memory system, guarantee that computer systems have acceptable performance but this parameter depends on many important system features. In this paper we will focus on one parameter, namely average disk time s/ transfer, in order to show the complex behavior of this memory system part during man-computer interaction. This is one of the most important counters in computer systems that works under Windows family operating systems and describes measurement related to hard drive based on the complete roundtrip time of any request

Systems reconfiguration via non-extensive statistics approach

W artykule pokazano, że czas życia systemów rekonfigurowalnych wpisuje się w przypadek super-ekstensywny, nieaddytywnej termodynamiki nierównowagowej i entropii Tsallisa, która oprócz składnika addytywnego o charakterze ilościowym, opisującym nierekonfigurowane struktury klasyczne, zawiera dodatkowy człon jakościowy wpisujący się w charakter struktur rekonfigurowalnych. Podejście to stanowi rozszerzenie klasycznej, addytywnej formuły entropii Boltzmanna-Gibbsa-Shannona. Badania dotyczą relacji pomiędzy postępem technologicznym określonym przez prawo Moore'a a czasem życia produktu w odniesieniu do struktur klasycznych i rekonfigurowalnych.The article shows that the time of living of reconfigurable systems can be described by non-extensive, non-additive, non-equilibrium thermodynamics and Tsallis entropy, which beside the additive linear component that describes classical non-reconfigurable structures , has got additional term that can characterize the reconfigurable structures. The presented approach is the enhancement of classical additive formula of Boltzman-Gibbs-Shannon entropy. The relation between technological progress described by Moore's law and product time of living for classical and reconfigurable structures was shown

Scalability limitations of asynchronous systems

Referat dotyczy ograniczeń skalowalności systemów asynchronicznych. Istotą badań był wpływ procesów o charakterze długoterminowym na degradację wydajności i czasu odpowiedzi systemu o skończonych zaso-bach. Pokazano, że generowanie procesów o charakterze długoterminowym można wyjaśnić na bazie termodynamiki nieekstensywnej.This paper deals with scalability limitations of asynchronous systems, Fig. 1. The impact of long-term processes on system performance degradation and response time, Fig. 4, has been investigated. As starting point of analysis we assume that asynchronous system is complex system in contrast to traditional models which based on simple systems, Fig. 2. This mean that investigations concern of influence of all system components together on performance disturbances in contradiction to independent particular component in the case of classical models. The idea presented in this paper shows how complex system behavior provide a good perspective to analysis and application asynchronous system

Computer network traffic analysis with the use of statistical self-similarity factor

The optimal computer network performance models require accurate traffic models, which can capture the statistical characteristic of actual traffic. If the traffic models do not represent traffic accurately, one may overestimate or underestimate the network performance. The paper presents confirmation of the self-similar nature of the selected protocols in the computer network communication layer. It shows that the good measure of self-similarity is a Hurst factor