Showing papers by "University of Maribor published in 2004"

The relationships among perceived quality, perceived risk and perceived product value

Abstract: Perceived value is an extremely important concept in marketing and many authors have dealt with it in recent years. In Slovenia perceived value of product is a rather neglected aspect of the research. Moreover, nobody has empirically researched the impact of individual factors on perceived value of a product. The researched target group was students – the fastest growing segment among the users of mobile phones in Slovenia. In their research the authors focused on two of the perceived value impact factors: perceived product quality and perceived risk. Based on literature and our own findings, their main researched objective was to design the model of relationships among perceived value, perceived quality and perceived risk. After the model had been tested with the method of structural equation modeling (LISREL 8.0), the authors found that statistically significant relationships (positive and negative, direct and indirect) among the concepts researched exist.

Inclusive measurement of the photon energy spectrum in b → sγ decays

Abstract: We report a fully inclusive measurement of the flavor changing neutral current decay $b\ensuremath{\rightarrow}s\ensuremath{\gamma}$ in the energy range $1.8\text{ }\mathrm{G}\mathrm{e}\mathrm{V}\ensuremath{\le}{E}_{\ensuremath{\gamma}}^{*}\ensuremath{\le}2.8\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$, covering 95% of the total spectrum. Using $140\text{ }\mathrm{f}{\mathrm{b}}^{\mathrm{\ensuremath{-}}\mathrm{1}}$, we obtain $\mathcal{B}(b\ensuremath{\rightarrow}s\ensuremath{\gamma})=(3.55\ifmmode\pm\else\textpm\fi{}{0.32}_{\ensuremath{-}0.31\ensuremath{-}0.07}^{+0.30+0.11})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, where the errors are statistical, systematic, and from theory corrections. We also measure the first and second moments of the photon energy spectrum above $1.8\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ and obtain $\ensuremath{\langle}{E}_{\ensuremath{\gamma}}\ensuremath{\rangle}=2.292\ifmmode\pm\else\textpm\fi{}0.026\ifmmode\pm\else\textpm\fi{}0.034\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ and $\ensuremath{\langle}{E}_{\ensuremath{\gamma}}^{2}\ensuremath{\rangle}\ensuremath{-}\ensuremath{\langle}{E}_{\ensuremath{\gamma}}{\ensuremath{\rangle}}^{2}=0.0305\ifmmode\pm\else\textpm\fi{}0.0074\ifmmode\pm\else\textpm\fi{}0.0063\text{ }{\mathrm{G}\mathrm{e}\mathrm{V}}^{2}$, where the errors are statistical and systematic.

Study of B-→D**0π-(D**0→D(*)+π-) decays

Abstract: We report the results of a study of charged B decays to the D(+/-)pi(-/+)pi(-/+) and D(*+/-)pi(-/+)pi(-/+) final states using complete D-(*) reconstruction. The contributions of two-body B-->D**pi decays with narrow (j=3/2) and broad (j=1/2) D** states have been determined and the masses and widths of four D** states have been measured. This is the first observation of the broad P-wave D-0*(0) and D'(0)(1) mesons. The analysis is based on a data sample of 65 million B(B) over bar pairs collected in the Belle experiment.

Correlation-based decomposition of surface electromyograms at low contraction forces.

Abstract: The paper studies a surface electromyogram (SEMG) decomposition technique suitable for identification of complete motor unit (MU) firing patterns and their motor unit action potentials (MUAPs) during low-level isometric voluntary muscle contractions. The algorithm was based on a correlation matrix of measurements, assumed unsynchronised (uncorrelated) MU firings, exhibited a very low computational complexity and resolved the superimposition of MUAPs. A separation index was defined that identified the time instants of an MU's activation and was eventually used for reconstruction of a complete MU innervation pulse train. In contrast with other decomposition techniques, the proposed approach worked well also when the number of active MUs was slightly underestimated, if the MU firing patterns partly overlapped and if the measurements were noisy. The results on synthetic SEMG show 100% accuracy in the detection of innervation pulses down to a signal-to-noise ratio (SNR) of 10 dB, and 93±4.6% (mean± standard deviation) accuracy with 0 dB additive noise. In the case of real SEMG, recorded with an array of 61 electrodes from biceps brachii of five subjects at 10% maximum voluntary contraction, seven active MUs with a mean firing rate of 14.1 Hz were identified on average.

Study of double charmonium production in e + e - annihilation at √(s)≈10.6 GeV

Abstract: We present a new analysis of double charmonium production in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation. The observation of the processes ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{\ensuremath{\eta}}_{c}$, $J/\ensuremath{\psi}{\ensuremath{\chi}}_{c0}$, and $J/\ensuremath{\psi}{\ensuremath{\eta}}_{c}(2S)$ is confirmed using a data set more than 3 times larger than that of Belle's previous report, and no evidence for the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}J/\ensuremath{\psi}$ is found. We perform an angular analysis for $J/\ensuremath{\psi}{\ensuremath{\eta}}_{c}$ production and set an upper limit on the production of $J/\ensuremath{\psi}J/\ensuremath{\psi}$. Processes of the type ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\psi}(2S)(c\overline{c}{)}_{\mathrm{r}\mathrm{e}\mathrm{s}}$ have been observed for the first time; their rates are found to be comparable to those of ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}(c\overline{c}{)}_{\mathrm{r}\mathrm{e}\mathrm{s}}$ processes.

Physical chemistry of encapsulation and release

Abstract: This review describes recently introduced methods of coating colloidal particles and fabrication of hollow multilayer polyelectrolyte capsules. Diffusion through multilayer, Donnan equilibria for ions inside and outside hollow spheres and mechanical properties are given in quantitative aspects.

Evidence for direct CP violation in B 0 → K + π - decays

Abstract: The evidence for direct charged particles (CP) violation in the decay B0→K+ π- was investigated with 253 fb-1 of data collected with the Belle detector at the KEKB e + e- collider. 275 x 106 BB pairs were used to observe a B→K±π∓ signal with 2140 ±53 events. Mixing induced CP violation in the B sector was established in b → ccs transitions. The result suggests large interference between tree and penguin diagrams and the existence of final state interactions.

Measurements of the [Formula presented] Resonance Properties

Abstract: We report measurements of the properties of the ${D}_{sJ}^{+}(2317)$ and ${D}_{sJ}^{+}(2457)$ resonances produced in continuum ${e}^{+}{e}^{\ensuremath{-}}$ annihilation near $\sqrt{s}=10.6\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. The analysis is based on an $86.9\text{ }\text{ }\mathrm{f}{\mathrm{b}}^{\mathrm{\ensuremath{-}}\mathrm{1}}$ data sample collected with the Belle detector at KEKB. We determine the masses to be $M\mathbf{(}{D}_{sJ}^{+}(2317)\mathbf{)}=2317.2\ifmmode\pm\else\textpm\fi{}0.5(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\ifmmode\pm\else\textpm\fi{}0.9(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{c}^{2}$ and $M\mathbf{(}{D}_{sJ}^{+}(2457)\mathbf{)}=2456.5\ifmmode\pm\else\textpm\fi{}1.3(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\ifmmode\pm\else\textpm\fi{}1.3(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{c}^{2}$. We observe the radiative decay mode ${D}_{sJ}^{+}(2457)\ensuremath{\rightarrow}{D}_{s}^{+}\ensuremath{\gamma}$ and the dipion decay mode ${D}_{sJ}^{+}(2457)\ensuremath{\rightarrow}{D}_{s}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and determine their branching fractions. No corresponding decays are observed for the ${D}_{sJ}(2317)$ state. These results are consistent with the spin-parity assignments of ${0}^{+}$ for the ${D}_{sJ}(2317)$ and ${1}^{+}$ for the ${D}_{sJ}(2457)$.

Measurement of the B→L*γ branching fractions and asymmetries

Abstract: We report measurements of the radiative decay B --> K^*\gamma. The analysis is based on a data sample containing 85.0*10^6 B meson pairs collected by the Belle detector at the KEKB storage ring. We measure branching fractions of Br(B^0 --> K^{*0}\gamma) = (4.01 \pm 0.21 \pm 0.17)*10^{-5} and Br(B^+ --> K^{*+}\gamma) = (4.25 \pm 0.31 \pm 0.24)*10^{-5}, where the first and second errors are statistical and systematic, respectively. The isospin asymmetry between B^0 and B^+ decay widths is measured to be \Delta_{0+} = +0.012 \pm 0.044 \pm 0.026. We search for a partial rate asymmetry between CP conjugate modes, and find A_{cp}(B --> K^*\gamma) = =0.015 \pm 0.044 \pm 0.012.

Robust bilateral control with Internet communication

Abstract: Smith predictor is a well-known method for compensating time delay in control systems. Therefore, it has been applied to many systems with time delay so far. However, delay time should be estimated precisely in this method. So, if time delay is fluctuant and unpredictable, like the communication delay over the Internet, performance of Smith predictor deteriorates. This paper proposes "Communication Disturbance Observer". It regards the error caused by time delay as disturbance torque (or acceleration), then it can observe and compensate the error. Furthermore, it doesn't need to estimate the value of delay time; therefore it can be applied to control systems with fluctuant and unpredictable time delay. It can be said that control system with "Communication Disturbance Observer" is robust to time delay and fluctuation of that. Effectiveness and robustness of proposed method is shown by result of simulation and experiment. In experiment, master-slave manipulator was used over the Internet. We were able to get the sense of touch from the environment of remote site.

Upper bound on the decay τ μγ from the Belle detector

Abstract: We have performed a search for the lepton-flavor-violating decay $\ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\gamma}$ using a data sample of $86.3\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ accumulated by the Belle detector at KEK. No evidence for a signal is seen, and we set an upper limit for the branching fraction of $\mathcal{B}(\ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\gamma})l3.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ at the 90% confidence level.

Determination of dissociable groups in natural and regenerated cellulose fibers by different titration methods

Abstract: Different titration methods were applied with the purpose to determine the dissociation properties of a natural (cotton) and regenerated (viscose, modal and lyocell) cellulose fibers. Potentiometric and conductometric titration were used to determine the content of acidic groups. pK values were determined by potentiometric titration. Polyelectrolyte adsorption was used for surface and total charge determination, and to obtain information about charge location and accessibility of charged groups. It was found that the average content of acidic groups is higher in cotton fibers than in regenerated fibers. The fiber charge of cotton is due to the dissociation of two type of acidic groups, one with pK ≈3.5 and the other with pK ≈5.5. In regenerated fibers there is only one type of acidic groups (pK ≈3.5). The pK value of the stronger acid is typical for carboxyl group in uronic acids. The polyelectrolyte adsorption indicates that most of the carboxyl groups are located in an inner region of all cellulose samples (cotton and regenerated fibers). It is concluded that titration methods are powerful tools for monitoring the content, strength, and distribution of acidic groups, as well as the total charge of natural and regenerated cellulose fibers. The three methods give similar results on all analyzed samples and show good repeatability. The results of investigation make it quite clear that combination of all titrations yields relevant information about content and strength of acidic groups in both natural and regenerated cellulose fibers used in the manufacture of textiles. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3186–3195, 2004

Observation of B + ∧ ∧K +

Abstract: We report the first observation of the charmless hyperonic B decay, B+-->LambdaLambdaK+, using a 140 fb(-1) data sample recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB (e+)(e-) collider. The measured branching fraction is B(B+-->LambdaLambdaK+) = (2.91(+0.90)(-0.70) +/- 0.38) x 10(-6). We also perform a search for the related decay mode B+-->LambdaLambdapi+, but do not find a significant signal. We set a 90% confidence-level upper limit of B(B+-->LambdaLambdapi+) < 2.8 x 10(-6).

Search for the Lepton-Flavor-Violating Decay τ-→μ-η at Belle

Abstract: We have searched for the lepton flavor violating decay tau(-)-->micro(-)eta using a data sample of 84.3 fb(-1) accumulated with the Belle detector at KEK. The eta meson was detected through the decay modes: eta-->gammagamma and pi(+)pi(-)pi(0). No signal candidates are found, and we obtain an upper limit for the branching fraction B(tau(-)-->micro(-)eta)<3.4 x 10(-7) at the 90% confidence level.

Observation of large CP violation and evidence for direct CP violation in B0 → π+ π- decays

Abstract: The CP violation parameters in Bo → π +π- decay were investigated. The flavor of the accompanying B meson was identified by reconstructing B o→π+π- CP eigenstate. It was observed that the expected sensitivity was optimized using the ratio LR. The study showed that there was a direct CP violation with a significance at or greater than 3.2σ.

How to restore Bertalanffian systems thinking

Abstract: Ludwig von Bertalanffy created general systems theory in an effort to counter the oversight and endangerment of humankind by disciplinary specialization. Bertalanffy desired for a holistic worldview and openness to replace overspecialization. Although widely cited and regarded, his concept prevailed only at a fictitious level, mostly as a tool inside specialization, which many scholars are neither able to overcome nor complement with interdisciplinary, creative co‐operation. Similarities (isomorphisms) are not enough. Here, a system of seven groups of systems thinking principles, which serve as a framework for restoring Bertalanffian systems thinking without his exaggerations is presented.

Measurement of φ3 with Dalitz plot analysis of B ± → D(*)K± decay

Abstract: We present a measurement of the unitarity triangle angle {phi}{sub 3} using a Dalitz plot analysis of the three-body decay of the neutral D meson from the B{sup {+-}}{yields}D{sup (*)}K{sup {+-}} process. The method employs the interference between D{sup 0} and D{sup 0} to extract both the weak and strong phases. We apply this method to a 140 fb{sup -1} data sample collected by the Belle experiment. The analysis uses the modes B{sup {+-}}{yields}DK{sup {+-}} and B{sup {+-}}{yields}D*K{sup {+-}}, D*{yields}D{pi}{sup 0}, where the neutral D meson decays into K{sub S}{pi}{sup +}{pi}{sup -}. We obtain 146 signal candidates for B{sup {+-}}{yields}DK{sup {+-}} and 39 candidates for B{sup {+-}}{yields}D*K{sup {+-}}. From a combined maximum likelihood fit to the B{sup {+-}}{yields}DK{sup {+-}} and B{sup {+-}}{yields}D*K{sup {+-}} modes, we obtain {phi}{sub 3}=77 deg. (+17 deg./-19 deg.)(stat){+-}13 deg. (syst){+-}11 deg. (model). The corresponding 2 standard deviation interval is 26 deg. <{phi}{sub 3}<126 deg.

Observation of B+ → ppπ+, B0 → ppk0, and B+ → ppK*+

Abstract: We report the first observation of a b-->u type charmless baryonic B decay, B+-->pppi(+), as well as b-->s type B0-->ppK0 and B+-->ppK(*+) decays. The analysis is based on a 78 fb(-1) data sample recorded on the Upsilon(4S) resonance with the Belle detector at KEKB. We find B(B+-->pppi(+))=(3.06(+0.73)(-0.62)+/-0.37)x10(-6), B(B0-->ppK0)=(1.88(+0.77)(-0.60)+/-0.23)x10(-6), and B(B+-->ppK(*+))=(10.3(+3.6+1.3)(-2.8-1.7))x10(-6). We also update B(B+-->ppK+)=(5.66(+0.67)(-0.57)+/-0.62)x10(-6) and present an upper limit on B(B0-->ppK(*0)) at the 90% confidence level. A common feature of the observed decay modes is threshold peaking in baryon pair invariant mass.

Study of B meson decays to three-body charmless hadronic final states

Abstract: We report results of a study of charmless B meson decays to three-body Kππ, KKπ and KKK final states. Measurements of branching fractions for B decays to K=+(0)π+π-, K +K+K-, K0K+K-, K+Ks 0Ks 0 and K s 0Ks 0Ks 0 final states are presented. The decays B0→K0K +K-, B+→K+Ks 0Ks 0 and B0→Ks 0Ks 0Ks 0 are observed for the first time. We also report evidence for B+→K +K-π+ decay. For the three-body final states K0K+π-, Ks 0K s 0π+, K+K+π - and K-π+π+, 90% confidence level upper limits are reported. Finally, we discuss the possibility of using the three-body B0→Ks 0K+K - decay for CP violation studies. The results are obtained with a 78 fb-1 data sample collected at the Y(4S) resonance by the Belle detector operating at the KEKB asymmetric energy e+e- collider. © 2004 The American Physical Society.