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41.
The effects of the excluded volume interactions on the conformational properties of star polymers have been studied. First order calculations at the critical dimensionality d = 4 yield the critical exponents of the average quantities up to first order in ε = 4-d. We thus find the partition function, the probability of the end of a branch to reach the central core and the probability of contact of the ends of two branches. The size of the macromolecule, expressed by the mean square radius of gyration 〈s2star is studied in the region where the interactions between the polymeric units repel one another and in the region where the units attract one another. The results are compared with the results of previous works and with experiments.  相似文献   
42.
LIQUID-LIQUID EXTRACTION IN A HOLLOW-FIBER DEVICE   总被引:1,自引:0,他引:1  
Liquid-liquid extraction operations were conducted in a hollow fiber mass transfer device using two systems: phenol/water vs. n-octanol and phenol/hexane vs. water. Individual mass transfer resistances due to the tube-side fluid, the hollow fiber wall (membrane), and the shell-side fluid were determined for runs in which the solvent was held stagnant on the shell-side. Countercurrent flow runs with moving solvent were conducted to show that the degree of extraction rises steadily as the solvent-to-raffinate ratio increases. Factors affecting the mass transfer resistances in this type of device are discussed, and the advantages of hollow fiber units over conventional mixer-settler units are pointed out.  相似文献   
43.
Face recognition on mobile devices, such as personal digital assistants and cell phones, is a big challenge owing to the limited computational resources available to run verifications on the devices themselves. One approach is to transmit the captured face images by use of the cell-phone connection and to run the verification on a remote station. However, owing to limitations in communication bandwidth, it may be necessary to transmit a compressed version of the image. We propose using the image compression standard JPEG2000, which is a wavelet-based compression engine used to compress the face images to low bit rates suitable for transmission over low-bandwidth communication channels. At the receiver end, the face images are reconstructed with a JPEG2000 decoder and are fed into the verification engine. We explore how advanced correlation filters, such as the minimum average correlation energy filter [Appl. Opt. 26, 3633 (1987)] and its variants, perform by using face images captured under different illumination conditions and encoded with different bit rates under the JPEG2000 wavelet-encoding standard. We evaluate the performance of these filters by using illumination variations from the Carnegie Mellon University's Pose, Illumination, and Expression (PIE) face database. We also demonstrate the tolerance of these filters to noisy versions of images with illumination variations.  相似文献   
44.
A lighting mast made of glass for the market place in Goeppingen. The paper presents the design and construction details of glass – lighting masts, whose prototype was developed for the shadowless lighting of the market place in Goeppingen. The cross‐shaped mast consists of a 2.0 m high plate‐base made of stainless‐steel and of a 6.0 m high glass column, made of four wings of composite safety glass, screwed on the top of it. The wings are connected to a centrally placed steel core in such a way, that the structure provides in a catastrophe case the necessary residual bearing capacity. Four multifaceted mirrors, placed at a height of 8.0 m, reflect the light‐beams that are projected by projectors, situated at the ground.  相似文献   
45.
In the present work, survival of Listeria monocytogenes in the traditional Greek soft, spreadable cheese Katiki was studied throughout the shelf life of the product. Samples of finished cheese were inoculated with a cocktail of five L. monocytogenes strains (ca. 6 log CFU g(-1)) and stored at 5, 10, 15, and 20 degrees C. Acid-stress adaptation or cross-protection to the same stress was also investigated by inoculation of acid-adapted cells in the product. The results showed that pathogen survival was biphasic. Various mathematical equations (Geeraerd, Cerf, Albert-Mafart, Whiting, Zwietering, and Baranyi models) were fitted to the experimental data. A thorough statistical analysis was performed to choose the best model. The Geeraerd model was finally selected, and the results revealed no acid tolerance acquisition (no significant differences, P > 0.05, in the survival rates of the non-acid-adapted and acid-adapted cells). Secondary modeling (second-order polynomial with a(0) = 0.8453, a(1) = -0.0743, and a(2) = 0.0059) of the survival rate (of sensitive population), and other parameters that were similar at all temperatures (fraction of initial population in the major population = 99.98%, survival rate of resistant population = 0.10 day(-1), and initial population = 6.29 log CFU g(-1)), showed that survival of the pathogen was temperature dependent with bacterial cells surviving for a longer period of time at lower temperatures. Finally, the developed predictive model was successfully validated at two independent temperatures (12 and 17 degrees C). This study underlines the usefulness of predictive modeling as a tool for realistic estimation and control of L. monocytogenes risk in food products. Such data are also useful when conducting risk assessment studies.  相似文献   
46.
The enormous energy use of the building sector and the requirements for indoor living quality that aim to improve occupants’ productivity and health, prioritize Smart Buildings as an emerging technology. The Heating, Ventilation and Air-Conditioning (HVAC) system is considered one of the most critical and essential parts in buildings since it consumes the largest amount of energy and is responsible for humans comfort. Due to the intermittent operation of HVAC systems, faults are more likely to occur, possibly increasing eventually building’s energy consumption and/or downgrading indoor living quality. The complexity and large scale nature of HVAC systems complicate the diagnosis of faults in a centralized framework. This paper presents a distributed intelligent fault diagnosis algorithm for detecting and isolating multiple sensor faults in large-scale HVAC systems. Modeling the HVAC system as a network of interconnected subsystems allows the design of a set of distributed sensor fault diagnosis agents capable of isolating multiple sensor faults by applying a combinatorial decision logic and diagnostic reasoning. The performance of the proposed method is investigated with respect to robustness, fault detectability and scalability. Simulations are used to illustrate the effectiveness of the proposed method in the presence of multiple sensor faults applied to a 83-zone HVAC system and to evaluate the sensitivity of the method with respect to sensor noise variance.   相似文献   
47.
48.
International Journal of Computer Vision - This paper presents a novel subject-dependent deep aging path (SDAP), which inherits the merits of both generative probabilistic modeling and inverse...  相似文献   
49.
This paper addresses the problem of fault‐tolerant control allocation for input affine nonlinear systems. The proposed scheme is divided in three main tasks: fault detection and estimation using a nonlinear observer, fault isolation through a bank of unknown input observers with a resetting policy to reduce the effects of nonlinearities and control reconfiguration based on reduced order allocation. Analytical results regarding the isolability and reconfigurability of actuator faults are derived and a simulation example is used to illustrate the the proposed fault tolerant control methodology.  相似文献   
50.
IT training is firmly established as a key condition that influences successful technology adoption, yet little is known about factors that can affect voluntary training participation. We evaluate the predictive value of IT-related attributional style in relation to the intention to participate in voluntary training in the context of a mandatory enterprise resource planning system rollout. We find that individual IT-related attributional style is highly predictive of the intention to participate.  相似文献   
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