Odhad únavy člověka: využitelnost systémů dopravy ve vnitřním prostředí

Fatigue monitoring is nowadays domain in traffic and transportation (e.g. system for driver's sleepness monitoring in cars or in trains). People working in offices are affected by fatigue too, but there is no general system that is able to monitor it. The fatigue in offices can cause decreasing work productivity or security risks in the industry. This review article compares the advantages and disadvantages of approaches used in traffic (e.g. an eye-movement tracking, driver activity) in internal environment (in buildings) with focus on people that work in offices with a computer. Because of the greater possibility of movement, it can not be enough. People are in offices longer than in cars and this causes that they are more affected by the quality of the internal environment. It should be useful to include this information in a system for fatigue monitoring. It can result in a system that is able to quantify fatigue level from both biological and environment variables.Sledování únavy člověka je dnes hlavně doménou dopravy (systémy pro sledování řidiče v moderních automobilech, systémy pro strojvedoucí, atd.). U lidí pracujících v kancelářích se únava prakticky nesleduje, přestože její vliv může mít negativní dopad nejen na kvalitu a produktivitu práce, ale v případě osob na velínech v průmyslu také možná bezpečností rizika. Tato rešeršní práce se zabývá možnostmi aplikace systémů pro monitoring únavy řidiče automobilu (např. z pohybu očí, aktivit při řízení) na osoby pracující v kancelářských prostorách. To se vzhledem k možnostem pohybu po kanceláři jeví jako nedostatečné. Protože člověk tráví v kanceláři typicky více času než v automobilu, ovlivňuje jej výrazněji vnitřní prostředí budov, které je vhodné do odhadu únavy také zahrnout. Výsledkem tak může být systém kvantifikující míru únavy zohledněním jak vnitřního prostředí, tak vybraných biologických signálů člověka snímaných na pracovním místě

A Clark-Ocone formula in UMD Banach spaces

Let H be a separable real Hilbert space and let F = (F_t)_{t\in [0,T]} be the augmented filtration generated by an H-cylindrical Brownian motion W_H on [0,T]. We prove that if E is a UMD Banach space, 1\leq p<\infty, and f\in D^{1,p}(E) is F_T-measurable, then f = \E f + \int_0^T P_F(Df) dW_H where D is the Malliavin derivative and P_F is the projection onto the F-adapted elements in a suitable Banach space of L^p-stochastically integrable L(H,E)-valued processes.Comment: 12 pages; revised version, to appear in Electronic Communications in Probabilit

Surface Potentials of Hydrophobic Microdomains in Aqueous Solutions of Poly(dimethyldiallylammonium-co-methyl-n-dodecyldiallylammonium salts) with Different Counterions. Evidence for the Existence of a Critical Aggregation Concentration

The solvatochromic acid-base indicator 1-hexadecyl-4-[(oxocyclohexadienylidene)ethylene]-1,4-dihydropyridine (HOED) was used to determine surface potentials (Y) of micelles formed from methyldiallyl-ndodecylammonium salts containing different counterions (MDDAX, X- = Cl, Br, I, benzoate, salicylate). Y decreased in the order Cl > Br > I > benzoate, salicylate consistent with conductometrically determined values for the counterion binding. HOED was also used to probe the microdomains formed in aqueous solutions of poly(dimethyldiallylammonium-co-methyl-n-dodecyldiallylammonium salts) containing different counterions (Copol C1-12 90/10 X). A similar dependence of Y on the nature of the counterion was found. Raising the temperature led to higher values of Y, while increasing the polysoap concentration appeared to lower the surface potentials for all polysoaps. With the exception of Copol C1-12 90/10 I and Sal, an additional peak in the UV-vis absorption spectrum of the probe was observed which was attributed to the aggregation of probe molecules on nondomain forming strains of the polysoap. Support for this conclusion was obtained from the observation that the intensity of the additional peak greatly decreased upon increasing the polysoap concentration. This behavior can be reconciled with the occurrence of a critical aggregation concentration. The sudden rise of the aggregation numbers of Copol C1-12 90/10 Br and benzoate at ca. 10 mM, leading to a constant value at higher concentrations, provides additional evidence for this conclusion

Effect of selected luminescent layers on CCT, CRI, and response times

Phosphors have been used as wavelength converters in illumination for many years. When it is excited with blue light, the frequently used yttrium aluminium garnet doped with cerium (YAG:Ce) phosphor converts a part of blue light to a wideband yellow light, resulting in the generated light having a white color. By combining an appropriate concentration of the YAG:Ce phosphor and blue excitant light, white light of a desired correlated color temperature (CCT) can be obtained. However, this type of illumination has a lower color rendering index value (CRI). In an attempt to improve the CRI value, we mixed the YAG:Ce phosphor with europium-doped calcium sulfide phosphor (CaS:Eu), which resulted in a considerably increased CRI value. This article examines an experiment with luminescent layers consisting of a mixture of selected phosphors and polydimethylsiloxane (PDMS). Different thicknesses in these layers were achieved by changing the speed of rotation during their accumulation onto laboratory glass using the method of spin coating. The spectral characteristics of these luminescent layers as they were excited with blue light emitting diode (LED) and laser diode (LD) were then determined. A suitable combination of the YAG:Ce phosphor with a phosphor containing europium, as it was excited with a blue LED, yielded a source of white light with a CRI value of greater than 85. The response time in the tested luminescent layers to a rectangular excitant impulse (generated by a signal generator and transmitted by LD) was also measured in order to examine their potential use in visible light communications (VLC).Web of Science1213art. no. 209

Formal Test Automation: The Conference Protocol with PHACT

We discuss a case study of automatic test generation and test execution based on formal methods. The case is the Conference Protocol, a simple, chatbox-like protocol, for which (formal) specifications and multiple implementations are publicly available and which is also used in other case study experiments. The tool used for test generation and test execution is Phact, the PHilips Automated Conformance Tester. The formal method is (Extented) Finite State Machines which is the input language for Phact. The experiment consists of developing a Finite State Machine specification for the Conference Protocol, generating 82 tests in TTCN with Phact, and executing these tests against 28 different implementations of the Conference Protocol, both correct and erroneous ones. The result is that some erroneous implementations are not detected by the test cases. These results are analysed, the merits of Extented Finite State Machines for specification are discussed, and the achievements of Phact are assessed. Moreover, the results are compared with a previous experiment in which the same 28 implementations were tested based on specifications in LOTOS and Promela

Eigenmode description of Raman scattering in atomic vapors in the presence of decoherence

A theoretical model describing the Raman scattering process in atomic vapors is constructed. The treatment investigates the low-excitation regime suitable for modern experimental applications. Despite the incorporated decoherence effects (possibly mode dependent) it allows for a direct separation of the time evolution from the spatial degrees of freedom. The impact of noise on the temporal properties of the process is examined. The model is applied in two experimentally relevant situations of ultra-cold and room-temperature atoms. The spatial eigenmodes of the Stokes photons and their coupling to atomic excitations are computed. Similarly, dynamics and the waveform of the collective atomic state are derived for quantum memory implementations.Comment: 11 pages, 5 figures, to appear in Phys. Rev.