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592. A comparative analysis of photosynthetic characteristics of hulless barley at two altitudes on the Tibetan Plateau
- Creator:
- Fan, Y. Z., Zhong, Z. M., and Zhang, X. Z.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, altitude, apparent quantum efficiency, maximum net photosynthesis, and Tibetan Plateau
- Language:
- Multiple languages
- Description:
- To determine the photosynthetic characteristics of C3 plants and their sensitivity to CO2 at different altitudes on the Tibetan Plateau, hulless barley (Hordeum vulgare L. ssp. vulgare) was grown at altitudes of 4,333 m and 3,688 m. Using gas-exchange measurements, photosynthetic parameters were simulated, including the maximum net photosynthesis (Pmax) and the apparent quantum efficiency (α). Plants growing at higher altitude had higher net photosynthetic rates (PN), photosynthesis parameters (Pmax and α) and sensitivities to CO2 enhancement than plants growing at lower altitude on the Tibetan Plateau. The enhancements of PN, Pmax, and α for plants growing at higher altitude, corresponding with 10 μmol(CO2) mol-1 increments, were approximately 0.20∼0.45%, 0.05∼0.20% and 0.12∼0.36% greater, respectively, than for plants growing at lower altitude, respectively, where CO2 levels rose from 10 to 170 μmol(CO2) mol-1. Therefore, on the Tibetan Plateau, the changes in the photosynthetic capacities and the photosynthetic sensitivities to CO2 observed in the C3 plants grown above 3,688 m are likely to increase with altitude despite the decreasing CO2 partial pressure. and Y. Z. Fan ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
593. A comparative study of friction factor correlations for high concentrate slurry flow in smooth pipes
- Creator:
- Assefa, K. M. and Kaushal, D. R.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Bingham fluid, smooth pipe, laminar flow, turbulent flow, friction factor, Reynolds number, correlations, and statistical parameters
- Language:
- Slovak
- Description:
- A number of correlations for friction factor determinations in smooth pipes have been proposed in the past decades. The accuracy and applicability of these friction factor formulas should be examined. Based on this notion the paper is designed to provide a comparative study of friction factor correlations in smooth pipes for all flow regimes of Bingham fluids. Nine models were chosen. The comparisons of the selected equations with the existing experimental results, which are available in the literature, were expressed through MARE, MRE+ , MRE- , RMSE, Ѳ, and S. The statistical comparisons were also carried out using MSC and AIC. The analyses show that the Wilson-Thomas (1985) and Morrison (2013) models are best fit models to the experimental data for the Reynolds number up to 40000. Within this range, both models can be used alternately. But beyond this Re value the discrepancy of the Wilson-Thomas model is higher than the Morrison model. In view of the fact that the Morrison model requires fewer calculations and parameters as well as a single equation is used to compute the friction factor for all flow regimes, it is the authors’ advice to use this model for friction factor estimation for the flow of Bingham fluids in smooth pipes as an alternative to the Moody chart and other implicit formulae.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
594. A comparative study of HMMs and DBNs applied to Facial Action Units Recognition
- Creator:
- Popa, M. C., Rothkrantz , L. J. M., Datcu , D., Wiggers, P., Braspenning , R., and Shan, C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Hidden Markov Models, Dynamic Bayesian Networks, Facial Action Units Recognition, and Facial Action Coding System
- Language:
- English
- Description:
- From a theoretical point of view, Hidden Markov Models (HMMs) and Dynamic Bayesian Networks (DBNs) are similar, still in practice they pose different challenges and perform in a different manner. In this study we present a comparative analysis of the two spatial-temporal classification methods: HMMs and DBNs applied to the Facial Action Units (AUs) recognition problem. The Facial Action Coding System (FACS) developed by Ekman and Friesen decomposes the face into 46 AUs, each AU being related to the contraction of one or more specific facial muscles. FACS proved its applicability to facial behavior modeling, enabling the recognition of an extensive palette of facial expressions. Even though a lot has been published on this theme, it is still difficult to draw a conclusion regarding the best methodology to follow, as there is no common basis for comparison and sometimes no argument is given why a certain classification method was chosen. Therefore, our main contributions reside in discussing and comparing the relative performance of the two proposed classifiers (HMMs vs. DBNs) and also of different Region of Interest (ROI) selections proposed by us and different optical flow estimation methods. We can consider our automatic system towards AUs classification an important step in the facial expression recognition process, given that even one emotion can be expressed in different ways, fact that suggests the complexity of the analyzed problem. The experiments were performed on the Cohn-Kanade database and showed that under the same conditions regarding initialization, labeling, and sampling, both classification methods produced similar results, achieving the same recognition rate of 89% for the classification of facial AUs. Still, by enabling non-fixed sampling and using HTK, HMMs rendered a better performance of 93% suggesting that they are better suited for the special task of AUs recognition.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
595. A comparative study of reactive hyperemia in human forearm skin and muscle
- Creator:
- Addor, G., Delachaux, A., Dischl, B., Hayoz, D., Liauder, L., Waeber, B., and Feihl, Francois
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, patologická fyziologie, ischemie, physiology, pathological physiology, ischemia, vasodilation, laser Doppler, strain gauge plethysmography, surrogate endpoint, acetylsalicylate, 14, and 612
- Language:
- English
- Description:
- Reactive hyperemia (RH) in forearm muscle or skin microcirculation has been considered as a surrogate endpoint in clinical studies of cardiovascular disea e. We evaluated two potential confounders that might limit such use of RH, namely laterality of measurement and intake of non-steroidal anti-inflammatory drugs (NSAIDS). Twenty-three young non-smoking healthy adults were enrolled. In Experiment 1 (n=16), the RH elicited by 3 min of ischemia was recorded in the muscle (strain gauge plethysmography, hand excluded) and skin (laser Doppler imaging) of both forearms. In Experiment 2 (n=7), RH was determined in the dominant forearm only, one hour following oral acetylsalicylic acid (1 g) or placebo. In Experiment 1, peak RH was identical in both forearms, and so were the corresponding durations of responses. RH lasted significantly less in muscle than in skin (p=0.003), a hitherto unrecognized fact. In the skin, acetylsalicylate reduced duration (43 vs. 57.4 s for placebo, p=0.03), without affecting the peak response. In muscle, duration tended to decrease with acetylsalicylate (21.4 vs. 26.0 s with placebo, p=0.06) and the peak increase in blood flow was blunted (27.2 vs. 32.4 ml/min/100 ml tissue with placebo, p=0.003). We conclude that, when using RH as a surrogate endpoint in studies of cardiovascular disease, a confounding by laterality of measurement need not be feared, but NSAIDS may have an influence, although perhaps not on the peak response in the skin., G. Addor, A. Delachaux, B. Dischl, D. Hayoz, L. Liaudet, B. Waeber, F. Feihl., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
596. A comparative study of two methodologies for binary datasets analysis
- Creator:
- Frolov, Alexander, Húsek , Dušan, Polyakov , Pavel Y., and Řezanková, Hana
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Dimension reduction, statistics, data mining, Boolean factor analysis, Boolean matrix factorization, information gain, likelihood-maximization, and bars problem
- Language:
- English
- Description:
- Studied are differences of two approaches targeted to reveal latent variables in binary data. These approaches assume that the observed high dimensional data are driven by a small number of hidden binary sources combined due to Boolean superposition. The first approach is the Boolean matrix factorization (BMF) and the second one is the Boolean factor analysis (BFA). The two BMF methods are used for comparison. First is the M8 method from the BMDP statistical software package and the second one is the method suggested by Belohlavek \& Vychodil. These two are compared to BFA, especially with the Expectation-maximization Boolean Factor Analysis we had developed earlier has, however, been extended with a binarization step developed here. The well-known bars problem and the mushroom dataset are used for revealing the methods' peculiarities. In particular, the reconstruction ability of the computed factors and the information gain as the measure of dimension reduction was under scrutiny. It was shown that BFA slightly loses to BMF in performance when noise-free signals are analyzed. Conversely, BMF loses considerably to BFA when input signals are noisy.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
597. A comparison between yellow-green and green cultivars of four vegetable species in pigments, ascorbate, photosynthesis, energy dissipation, and photoinhibition
- Creator:
- Weng, J.-H., Chien, L.-F., Jiang, C.-Y., Shih, F.-C., and Chen, H.-Y.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, Amaranthus tricolor, ascorbate-deficient, Brassica oleracea var. alboglabra, Brassica rapa, chlorophyll-deficient, energy dissipation, Ipomoea batatas, photoinhibition, and photosynthesis
- Language:
- Multiple languages
- Description:
- Yellow-green foliage cultivars of four vegetables grown outdoors, i.e., Chinese mustard (Brassica rapa), Chinese kale (Brassica oleracea var. alboglabra), sweet potato (Ipomoea batatas) and Chinese amaranth (Amaranthus tricolor), had lower chlorophyll (Chl) (a+b) (29-36% of green cultivars of the same species), total carotenoids (46-62%) and ascorbate (72-90%) contents per leaf area. Furthermore, yellow-green cultivars had smaller photosystem II (PSII) antenna size (65-70%) and lower photosynthetic capacity (52-63%), but higher Chl a/b (107-156%) and from low (60%) to high (129%) ratios of de-epoxidized xanthophyll cycle pigments per Chl a content. Potential quantum efficiency of PSII (Fv/Fm) of all overnight dark-adapted leaves was ca. 0.8, with no significant difference between yellow-green and green cultivars of the same species. However, yellow-green cultivars displayed a higher degree of photoinhibition (lower Fv/Fm after illumination) when they were exposed to high irradiance. Although vegetables used in this study are of either temperate or tropical origin and include both C3 and C4 plants, data from all cultivars combined revealed that Fv/Fm after illumination still showed a significant positive linear regression with xanthophyll cycledependent energy quenching (qE) and a negative linear regression with photoinhibitory quenching (qI). Fv/Fm was, however, not correlated with nonphotochemical quenching (NPQ). Yet, a higher degree of photoinhibition in yellow-green cultivars could recover during the night darkness period, suggesting that the repair of PSII in yellow-green cultivars would allow them to grow normally in the field. and J.-H. Weng ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
598. A comparison of evidential networks and compositional models
- Creator:
- Vejnarová, Jiřina
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- evidence theory, conditioning, independence, and directed graphs
- Language:
- English
- Description:
- Several counterparts of Bayesian networks based on different paradigms have been proposed in evidence theory. Nevertheless, none of them is completely satisfactory. In this paper we will present a new one, based on a recently introduced concept of conditional independence. We define a conditioning rule for variables, and the relationship between conditional independence and irrelevance is studied with the aim of constructing a Bayesian-network-like model. Then, through a simple example, we will show a problem appearing in this model caused by the use of a conditioning rule. We will also show that this problem can be avoided if undirected or compositional models are used instead.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
599. A comparison of numerical models results with in-situ measurement of ground vibrations caused by sheet pile driving
- Creator:
- Tomáš Petřík, Eva Hrubešová, and Markéta Lednická
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, numerické modelování, numerical modeling, dynamic analysis, Plaxis 2D, sheet pile driving, vibration velocity amplitude, vibration frequency, vibratory hammer, 7, and 551
- Language:
- English
- Description:
- This paper pursues the effect of changes in distance and vibration frequency on the vibration velocity amplitude. As an example, we used the vibrating sheet piles at the cons truction of a new multi-functional FEI building on the premises of VŠB - TU Ostrava, at 17 listopadu street. The effect of these changes is monitored both in in-situ measurements and in a simulated real-life situation. The calculation software Plaxis 2D is used for creation of numer ical models. At the close, the results from in-situ measurements are confronted with those achieved from the models., Tomáš Petřík, Eva Hrubešová and Markéta Lednická., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
600. A comparison of photosynthesis in endangered and non-endangered plants Changium smyrnioides and Anthriscus sylvestris
- Creator:
- Chang, J., Ge, Y., Lu, Y.-J., Yin, X.-W., and Fan, M.- Y.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- leaf area ratio, leaf mass ratio, net photosynthetic rate, and specific leaf area
- Language:
- Multiple languages
- Description:
- Changium smyrnioides Wolff. and Anthriscus sylvestris (L.) Hoffm. have similar photosynthetic characters; they use radiant energy in winter and early spring effectively, but cannot take full advantage of higher irradiance after spring. The specific leaf area (SLA), leaf area ratio (LAR), and leaf mass ratio (LMR) of C. smyrnioides were lower than those of A. sylvestris. The photosynthetic period of C smyrnioides was about 160 d shorter than that of A. sylvestris, causing the total photosynthetic production of C. smyrnioides to be lower than that of A. sylvestris. Hence if C. smyrnioides is disturbed, it could not recover within a short period. and J. Chang ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public