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排序方式: 共有343条查询结果,搜索用时 15 毫秒
91.
Antonios Vlachos Persefoni Tserkezou 《Critical reviews in food science and nutrition》2016,56(7):1061-1096
Adulteration of foods is a serious economic problem concerning most foodstuffs, and in particular meat products. Since high-priced meat demand premium prices, producers of meat-based products might be tempted to blend these products with lower cost meat. Moreover, the labeled meat contents may not be met. Both types of adulteration are difficult to detect and lead to deterioration of product quality. For the consumer, it is of outmost importance to guarantee both authenticity and compliance with product labeling. The purpose of this article is to review the state of the art of meat authenticity with analytical and immunochemical methods with the focus on the issue of geographic origin and sensory characteristics. This review is also intended to provide an overview of the various currently applied statistical analyses (multivariate analysis (MAV), such as principal component analysis, discriminant analysis, cluster analysis, etc.) and their effectiveness for meat authenticity. 相似文献
92.
J. Antonios N. Ginot C. Batard Y. Scudeller M. Machmoum 《Microelectronics Journal》2012,43(6):345-352
This paper presents a model reduction approach for constructing lumped RC thermal networks of IGBT-modules of inverters for which heat and subsequent temperature increases vary with time on different scales ranging from nanosecond to second. It was observed that the time-dependent heat and temperature profiles of transistors and diodes of IGBT-modules of inverters oscillate at two frequencies, one in the range 0.1–50 Hz corresponding to the load current modulation, and the other in the range 1–20 kHz corresponding to the switching frequency. The reduction approach consisted of decomposing the module into different elements, each being described with a number of RC cells selected according to the time-constant of the element with regard to the module. The lumped RC thermal networks were found in good agreement with the continuous model by offering a considerably lower computational time on the different time scales. For simplicity, the reduction approach is presented for one-dimensional heat flow through the cross-plane direction of the module. 相似文献
93.
Alexander M. Tatara Allison J. Rozich Panayiotis D. Kontoyiannis Emma Watson Nathaniel D. Albert George N. Bennett Antonios G. Mikos 《Journal of materials science. Materials in medicine》2018,29(5):70
While antibiotic-eluting polymethylmethacrylate space maintainers have shown efficacy in the treatment of bacterial periprosthetic joint infection and osteomyelitis, antifungal-eluting space maintainers are associated with greater limitations for treatment of fungal musculoskeletal infections including limited elution concentration and duration. In this study, we have designed a porous econazole-eluting space maintainer capable of greater inhibition of fungal growth than traditional solid space maintainers. The eluted econazole demonstrated bioactivity in a concentration-dependent manner against the most common species responsible for fungal periprosthetic joint infection as well as staphylococci. Lastly, these porous space maintainers retain compressive mechanical properties appropriate to maintain space before definitive repair of the joint or bony defect. 相似文献
94.
Dimitris Sacharidis Antonios Deligiannakis Timos Sellis 《The VLDB Journal The International Journal on Very Large Data Bases》2009,18(1):203-231
The wavelet decomposition is a proven tool for constructing concise synopses of large data sets that can be used to obtain
fast approximate answers. Existing research studies focus on selecting an optimal set of wavelet coefficients to store so
as to minimize some error metric, without however seeking to reduce the size of the wavelet coefficients themselves. In many
real data sets the existence of large spikes in the data values results in many large coefficient values lying on paths of
a conceptual tree structure known as the error tree. To exploit this fact, we introduce in this paper a novel compression
scheme for wavelet synopses, termed hierarchically compressed wavelet synopses, that fully exploits hierarchical relationships
among coefficients in order to reduce their storage. Our proposed compression scheme allows for a larger number of coefficients
to be stored for a given space constraint thus resulting in increased accuracy of the produced synopsis. We propose optimal,
approximate and greedy algorithms for constructing hierarchically compressed wavelet synopses that minimize the sum squared
error while not exceeding a given space budget. Extensive experimental results on both synthetic and real-world data sets
validate our novel compression scheme and demonstrate the effectiveness of our algorithms against existing synopsis construction
algorithms.
This work has been funded by the project PENED 2003. The project is co-financed 75% of public expenditure through EC—European
Social Fund, 25% of public expenditure through Ministry of Development—General Secretariat of Research and Technology and
through private sector, under measure 8.3 of OPERATIONAL PROGRAMME “COMPETITIVENESS" in the 3rd Community Support Programme. 相似文献
95.
This paper proposes a new method for reduction of the number of gray-levels in an image. The proposed approach achieves gray-level reduction using both the image gray-levels and additional local spatial features. Both gray-level and local feature values feed a self-organized neural network classifier. After training, the neurons of the output competition layer of the SOFM define the gray-level classes. The final image has not only the dominant image gray-levels, but also has a texture approaching the image local characteristics used. To split the initial classes further, the proposed technique can be used in an adaptive mode. To speed up the entire multithresholding algorithm and reduce memory requirements, a fractal scanning subsampling technique is adopted. The method is applicable to any type of gray-level image and can be easily modified to accommodate any type of spatial characteristic. Several experimental and comparative results, exhibiting the performance of the proposed technique, are presented. 相似文献
96.
Zoi Kaoudi Manolis Koubarakis Kostis Kyzirakos Iris Miliaraki Matoula Magiridou Antonios Papadakis-Pesaresi 《Journal of Web Semantics》2010,8(4):271-277
The RDF(S) data model has been proposed for encoding metadata about Web resources. As more and more Web resources are annotated using RDF(S), there is an urgent need for efficiently dealing with this large volume of data. In this paper, we present Atlas, a peer-to-peer system for storing, updating and querying RDF(S) data. The Atlas system has been built using the distributed hash table Bamboo. Atlas was developed in the context of project OntoGrid, where it was used as a distributed repository for RDF(S) metadata describing Grid services and resources. The development of Atlas continues in other projects that our group participates currently. This paper gives an overview of the most recent version of Atlas and discusses a representative application. 相似文献
97.
Antonios Alexiou Dimitrios Antonellis Christos Bouras 《International Journal of Communication Systems》2007,20(1):65-81
This paper proposes a mechanism for the congestion control for video transmission over universal mobile telecommunications system (UMTS). Our scheme is applied when the mobile user experiences real‐time multimedia content and adopts the theory of a widely accepted rate control method in wired networks, namely equation‐based rate control. In this approach, the transmission rate of the multimedia data is determined as a function of the packet loss rate, the round trip time and the packet size and the server explicitly adjusts its sending rate as a function of these parameters. Furthermore, we examine the performance of the UMTS for real‐time video transmission using real‐time protocols. Through a number of experiments, we measure performance parameters such as end‐to‐end delay, delay in radio access network, delay jitter and throughput in the wireless link. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
98.
Alice Caldiroli Enrico Capuzzi Ilaria Tagliabue Martina Capellazzi Matteo Marcatili Francesco Mucci Fabrizia Colmegna Massimo Clerici Massimiliano Buoli Antonios Dakanalis 《International journal of molecular sciences》2021,22(23)
Treatment resistant depression (TRD) is associated with poor outcomes, but a consensus is lacking in the literature regarding which compound represents the best pharmacological augmentation strategy to antidepressants (AD). In the present review, we identify the available literature regarding the pharmacological augmentation to AD in TRD. Research in the main psychiatric databases was performed (PubMed, ISI Web of Knowledge, PsychInfo). Only original articles in English with the main topic being pharmacological augmentation in TRD and presenting a precise definition of TRD were included. Aripiprazole and lithium were the most investigated molecules, and aripiprazole presented the strongest evidence of efficacy. Moreover, olanzapine, quetiapine, cariprazine, risperidone, and ziprasidone showed positive results but to a lesser extent. Brexpiprazole and intranasal esketamine need further study in real-world practice. Intravenous ketamine presented an evincible AD effect in the short-term. The efficacy of adjunctive ADs, antiepileptic drugs, psychostimulants, pramipexole, ropinirole, acetyl-salicylic acid, metyrapone, reserpine, testosterone, T3/T4, naltrexone, SAMe, and zinc cannot be precisely estimated in light of the limited available data. Studies on lamotrigine and pindolol reported negative results. According to our results, aripiprazole and lithium may be considered by clinicians as potential effective augmentative strategies in TRD, although the data regarding lithium are somewhat controversial. Reliable conclusions about the other molecules cannot be drawn. Further controlled comparative studies, standardized in terms of design, doses, and duration of the augmentative treatments, are needed to formulate definitive conclusions. 相似文献
99.
Stephen J. Lombardo David Bianchi Bruce Bishop Antonios Giannakopoulos Robert Goldsmith Richard Higgins Richard Pober Subra Suresh 《Journal of the American Ceramic Society》1999,82(6):1401-1408
A method to form thin ceramic bodies is described in which curvature in the component is introduced at high temperature without the application of an external stress. The internal stress that drives the deformation results as a consequence of cation penetration from a coating into a substrate material. This technique has been developed for alumina substrates that are coated with layers of chromia, magnesia, titania, calcia, silica, and iron oxide. Normalized deflections of segment height to sample thickness ( A/t ) of up to 10 were observed for samples with beam geometry and A/t values of 4 were obtained for disks. The magnitude of the deflection is dependent on the amount of dopant that is applied, as well as the soak temperature and time. An analytical model has been developed to describe the magnitude of the deflections. The best agreement with the experimental data is obtained when the deflections are treated as occurring at high temperature, where the resistance to bending from stiffness effects is reduced. This forming method is shown to be suitable to produce shapes of moderate complexity, such as ceramic wave springs. 相似文献
100.
Phetdaphat Boonsuk Apinya Sukolrat Kaewta Kaewtatip Sirinya Chantarak Antonios Kelarakis Chiraphon Chaibundit 《应用聚合物科学杂志》2020,137(26):48848
We report a systematic investigation on the structure–property relationships in glycerol-plasticized poly(vinyl alcohol) (PVA)/cassava starch blends prepared via solution casting. In particular, PVA mixed with native, low-oxidized, high-oxidized, and pregelatinized cassava starches were characterized by means of SEM, XRD, FTIR, thermal analysis and mechanical testing and the immiscible systems were received. Burial tests over a period of several days suggested the preferential degradation of the starch and glycerol component (as indicated by the absence of FTIR signatures of those components) and the amorphous phase of PVA (as indicated by the enhanced crystallinity index of the degraded samples). The rheological properties of the blends seem to dictate their morphological characteristics that, in turn, have a profound impact on their mechanical properties. In that sense, the study highlights promising strategies for the development of a new family of polymeric materials that combine their biodegradable nature within superior mechanical properties. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48848. 相似文献