The paper contains a sensitivity analysis of the influence of uncertainties in input hydrological, morphological and operating data required for a proposal for active reservoir conservation storage capacity and its achieved values. By introducing uncertainties into the considered inputs of the water management analysis of a reservoir, the subsequent analysed reservoir storage capacity is also affected with uncertainties. The values of water outflows from the reservoir and the hydrological reliabilities are affected with uncertainties as well. A simulation model of reservoir behaviour has been compiled with this kind of calculation as stated below. The model allows evaluation of the solution results, taking uncertainties into consideration, in contributing to a reduction in the occurrence of failure or lack of water during reservoir operation in low-water and dry periods.
Cílem dvou provedených studií je zjišťování psychometrických vlastností české verze Škály na měření důležitosti morální identity. Škála se skládá z devíti morálních vlastností vystihujících morální osobnost. Měří dvě dimenze morální identity, internalizaci a symbolizaci. Pro analýzu jsme si zvolili autory originální 13 položkovou škálu. Na základě statistické analýzy v pilotní studii (n = 163) jsme z původní škály vyloučili dvě položky, které nesplňovaly stanovená psychometrická kritéria. V druhé studii, na jiném souboru respondentů (n = 185), jsme následně ověřovali míru interní konzistence upravené 11 položkové škály. Konstruktovou validitu jsme měřili pomocí nástrojů měřících morální vyvázání a podvádění v práci. Na základě dosažených výsledků v naší studii doporučujeme zvážit pro použití v české populaci námi navrhovanou, jedenácti položkovou alternativu dotazníku, u které jsme zjistili dostatečně dobré základní psychometrické charakteristiky. and Two studies aim to determine the psychometric properties of the Czech version of The SelfImportance of Moral Identity Scale (Aquino, Reed, 2002). The scale consists of nine moral personality qualities that measure two dimensions of moral identity: internalization and symbolization. For the analysis, we chose the authors' 13-item scale originally proposed. Based on the statistical analysis in the pilot study (n = 163), we excluded from the original scale two items that did not meet the established psychometric criteria. In the second study, on a different set of respondents (n = 185), we subsequently verified the degree of internal consistency of the adjusted 11-item scale. We measured construct validity using tools measuring moral untying and cheating at work. Based on the results obtained in our study, we recommend considering the proposed eleven-item alternative of the questionnaire for use in the Czech population, for which we found sufficiently good basic psychometric characteristics.
Human society needs still more intensive exploitation of all kinds of
transportation facilities. This need has already lasted for several decades and will be much more imperative in future. Mobility is one of the basic requirements for survival, besides the energy and food resources, health care and security. The requirements on transportation systems concern not only the quantitative and qualitative aspects of transportation activities, but still more also the aspects of their reliability and safety. This concerns not only the transported subjects or goods but also the environment.
The losses caused by failures of transportation activities reach even now a very high level and if not limited by systematic research and preventive activity, they will reach quite a tremendous level soon.
However, practically all the conternporary transportation vehicles, trains, ships and planes and also all the transportation systems need, for their proper operation, the interaction with human beings, which drive them, controls them or uses them and maintains them.
In spite of the fact that significant progress was made in recent years as concerns the transportation systems automation, the fully automatic transportation systam in use is still foreseen in the considerably far future.
Analyzing the reliability and safety of transportation, one finds that the activity of a human being is the weakest point. The technical reliability of almost all transportation tools has improved quite a lot in the past years; however, the human subject interacting with them has not changed too much, as for his/her reliability and safety of the respective necessary interaction.
Therefore there is a vital necessity to improve it and the possibilities how to implement it will stay more and more in the focus of our interest.
In this paper an overview of the related problems is made, the challenges for further research and development in this area are discussed and the outline of a vision, with respect to human interaction reliability, of optimized transportation systems is presented.
Both Scientists and System Analytics share common experience that complex interfaces (for example "human - machine" interface within the complex hybrid system, or synapse in the human brain) susceptibly react both to the dimension of the task (i.e.: the number / type of interface parameters / markers) and to the degree of uncertainty.
In order to quantitatively evaluate this effect, the model of interface is presented first. Then the problem is analyzed. The results of the study indicate:
Even a low degree of uncertainty, "acting" homogeneously on all parameters of the respective interface, has significantly adverse effect on the interface regularity (consequently the reliability of systems processes as well) if the number of parameters (i.e. dimension of the pertinent task) is sufficiently high.
Even a significant uncertainty in one or in a small number (typically 1 or 2) of interface parameters has a limited or negligible impact on the interface regularity if this interface is sufficiently robust.
There are three basic attempts how to increase the regularity of complex interfaces: (a) smart simplification (b) utilizing redundancy or contextuality (c) interface conjugation.
Impaired wakefulness in machine operators poses a danger not only to themselves but often to the public at large as well. While on duty, such persons are expected to be continuously, i.e., without interruption, on the alert. For that purpose, we designed and carried out an experimental model of continuous vigilance monitoring using electroencephalography (EEG) and reaction time measured as the latency of the probanďs reaction to sound stimulus. If constructed, the set together with other logical elements and an alarm systém can be used for an autornatic detection of vigilance and, possibly, also of arousal stimuli in cases of micro-sleep.
Transportation of people and goods represents a still more significant
component of the human culture. Its influence is extremely high today and will increase greatly in the future.
Almost all the contemporary transportation systems are based on the necessity of interaction between the transportation tool (vehicle, plane, ship), the transport control system and the human subject. Though a large effort is put into the development of automatic transport systems, none of the present attempts is fully automatic, in all of them the human subject plays a non-neglectable role with considerably high impact on the reliability and safety of the transportation function. Among such functions the driving and control activity dominates.
The drivers, pilots, captains and transportation systems dispatchers and controllers are usually exposed to considerably long and exhausting Services, which could last up to 8 and even more hours.
It is generally known that the human subject is not able to retain in the state of vigilance without brakes and relaxation. Usually, its ability to concentrate his/her attention to some activity (like driving of systém control) decreases considerably soon, mainly after 45 or 60 niinutes only.
The decrease of human subject attention in the course of his/her activity is not monotone of course, it can involve several periods of temporary increases and decreases. However, without exception, if the exposition is long enough, the subject attention finally falls under the limit of acceptability for safe and reliable activity of the particular type. The subject activity becomes dangerous for him/her, his/her environment and for the driven vehicle, plane, ship or the controlled transportation system too. Finally, the subject falls in the stage of the so-called micro-sleep, in which he/she is not able to produce the particular driving or control activity at all.
A considerably large effort was given to the analysis of negative impacts of this factor. Unfortunately, the used methodology for such analyses differs up to now in many countries, so that the results are not quite comparable. However, one can estimate that between 15 and 40% of all the accidents on the roads are caused by the non-satisfactory level of the human subject attention. If we take into account that the average economic loss of one mortal road accident is estimated to more than 1 million Euro and if the density of such accidents is taken into account as well, we come to a tremendous figure, which has to be enlarged more by the estimation of losses of non-mortal accidents.
This article outlines how different types of survey response reliability are estimated and used within the social sciences. Implementing the Classical Test Theory’s concept of reliability in a panel survey exploring opinions and attitude crystallization in a Czech town. Estimates of the test-retest reliability of respondents’ political orientation are estimated using four different approaches. Political orientation is measured using a standard 10 point left-right scale. It also estimates the ‘true score’ of a respondents’ political orientation; and shows the implications of measurement precision for the estimation of this individual level trait. Inter-item reliability is calculated using a 4 item scale composed of dichotomous indicators. This analysis reveals that the estimated reliability of the political orientation scale depends on the number of items used to construct the scale. More concretely the 10 point left-right political orientation scale exhibits a satisfactory level of test-retest reliability demonstrating its validity in making inferences about the target population. The analyses presented in this study were estimated using the R statistical programming language and LISREL – a specialized software package for estimating structural equation models.
The aim of this article is to present a trend in research on measurement error in survey data and to suggest some problematic aspects of this approach. The article describes the Multitrait Multimethod experimental design and its modifi cation into a 2 Split-ballot Multitrait Multimethod (2 SB MTMM), which is used for experimental data collection in the European Social Survey. The text shows how to analyze 2 SB MTMM data to obtain estimates of construct validity, reliability and common method variance for a single questionnaire item, and how to make use of these estimates. It also points to some problems encountered in 2 SB MTMM data analysis., Johana Chylíková., and Obsahuje bibliografii
Computer support of design activities within precision devices speeds up achieving proper technical solutions, makes documentation to be developed more easily and reduces risk of making errors. Computer simulation of operation of devices being designed plays a significant role in this process. Besides performance characteristics of the device determined this way it also seems to be important to predict analytically other kinds of product characteristics i.e. reliability and availability. A concept of modelling of electrical drive systems for precision devices, verified along the years there is presented in the paper. It seems to be convenient from the point of view of designer. A proposal to utilise simulation results for better prediction of the device reliability is added. and Obsahuje seznam literatury
The article presents estimates of the reliability of measurement in the Czech surveys carried out in the EU-SILC international longitudinal research project. The reliability estimates were obtained using the Quasi Simplex Model (QSM), which has never before been used in Czech research. An analysis was carried out on all the items in the EU-SILC questionnaire that fulfilled the criteria for the QSM analysis: PH010, the item that asks respondents about their subjective health, HS120, the item that asks about the household’s financial situation, and HS130, which asks what the minimum sufficient income of a household is. The analysis drew on all available data from Czech EU-SILC surveys, that is, data from five rotating panel surveys carried out between 2005 and 2012. The QSM analysis showed that for the selected items EU-SILC data are highly reliable; the estimated reliability of each item was around 0.8, for HS130 it was even above 0.9. The steadiness of the results was confirmed by the high consistency of the reliability estimates across all the panels. A small difference was observed between the reliability of data collected using the PAPI mode and data collected using CAPI. Given the attributes of the QSM model, however, it was impossible to test statistically whether the reliability of PAPI and CAPI data differ significantly.