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排序方式: 共有473条查询结果,搜索用时 15 毫秒
41.
Shape is an important consideration in green building design due to its significant impact on energy performance and construction costs. This paper presents a methodology to optimize building shapes in plan using the genetic algorithm. The building footprint is represented by a multi-sided polygon. Different geometrical representations for a polygon are considered and evaluated in terms of their potential problems such as epistasis, which occurs when one gene pair masks or modifies the expression of other gene pairs, and encoding isomorphism, which occurs when chromosomes with different binary strings map to the same solution in the design space. Two alternative representations are compared in terms of their impact on computational effectiveness and efficiency. An optimization model is established considering the shape-related variables and several other envelope-related design variables such as window ratios and overhangs. Life-cycle cost and life-cycle environmental impact are the two objective functions used to evaluate the performance of a green building design. A case study is presented where the shape of a typical floor of an office building defined by a pentagon is optimized with a multi-objective genetic algorithm. 相似文献
42.
Radu Grosu X. Huang S. Jain S.A. Smolka 《Electronic Notes in Theoretical Computer Science》2006,144(3):27
We present GMC2, a software model checker for GCC, the open-source compiler from the Free Software Foundation (FSF). GMC2, which is part of the GMC static-analysis and model-checking tool suite for GCC under development at SUNY Stony Brook, can be seen as an extension of Monte Carlo model checking to the setting of concurrent, procedural programming languages. Monte Carlo model checking is a newly developed technique that utilizes the theory of geometric random variables, statistical hypothesis testing, and random sampling of lassos in Büchi automata to realize a one- sided error, randomized algorithm for LTL model checking. To handle the function call/return mechanisms inherent in procedural languages such as C/C++, the version of Monte Carlo model checking implemented in GMC2 is optimized for pushdown-automaton models. Our experimental results demonstrate that this approach yields an efficient and scalable software model checker for GCC. 相似文献
43.
Dynamic diffusion model for tracing the real-time potential response of polymeric membrane ion-selective electrodes 总被引:1,自引:0,他引:1
A numerical solution for the prediction of the time-dependent potential response of a polymeric-based ion-selective electrode (ISE) is presented. The model addresses short- and middle-term potential drifts that are dependent on changes in concentration gradients in the aqueous sample and organic membrane phase. This work has important implications for the understanding of the real-time response behavior of potentiometric sensors with low detection limits and with nonclassical super-Nernstian response slopes. As a model system, the initial exposure of membranes containing the well-examined silver ionophore O,O' '-bis[2-(methylthio)ethyl]-tert-butylcalix[4]arene was monitored, and the large observed potential drifts were compared to theoretical predictions. The model is based on an approximate solution of the diffusion equation for both aqueous and organic diffusion layers using a numerical scheme (finite difference in time and finite elements in space). The model may be evaluated on the basis of experimentally available parameters and gives time-dependent information previously inaccessible with a simpler steady-state diffusion model. For the cases studied, the model gave a very good correlation with experimental data, albeit with lower than expected diffusion coefficients for the organic phase. This model may address numerous open questions regarding the response time and memory effects of low-detection-limit ion-selective electrodes and for other membrane electrodes where ion fluxes are relevant. 相似文献
44.
Using the fact that the Parikh matrix mapping is not an injective mapping, the paper investigates some properties of the set of words with the same Parikh matrix; these words are called “amiable”. The presented results extend the results obtained in [A. Atanasiu, Binary amiable words, Int. J. Found. Comput. Sci. 18 (2) (2007) 387–400] for the binary case. In particular it is shown that all the words having the same Parikh matrix can be obtained one from another by applying only two types of transformations. Moreover, the mirrors of two amiable words are also amiable (thus forming a symmetrical class of words). 相似文献
45.
Erica Bazzan Mariaenrica Tin Alvise Casara Davide Biondini Umberto Semenzato Elisabetta Cocconcelli Elisabetta Balestro Marco Damin Claudia Maria Radu Graziella Turato Simonetta Baraldo Paolo Simioni Paolo Spagnolo Marina Saetta Manuel G. Cosio 《International journal of molecular sciences》2021,22(12)
Extracellular vesicles (EVs) are a family of particles/vesicles present in blood and body fluids, composed of phospholipid bilayers that carry a variety of molecules that can mediate cell communication, modulating crucial cell processes such as homeostasis, induction/dampening of inflammation, and promotion of repair. Their existence, initially suspected in 1946 and confirmed in 1967, spurred a sharp increase in the number of scientific publications. Paradoxically, the increasing interest for EV content and function progressively reduced the relevance for a precise nomenclature in classifying EVs, therefore leading to a confusing scientific production. The aim of this review was to analyze the evolution of the progress in the knowledge and definition of EVs over the years, with an overview of the methodologies used for the identification of the vesicles, their cell of origin, and the detection of their cargo. The MISEV 2018 guidelines for the proper recognition nomenclature and ways to study EVs are summarized. The review finishes with a “more questions than answers” chapter, in which some of the problems we still face to fully understand the EV function and potential as a diagnostic and therapeutic tool are analyzed. 相似文献
46.
The role of two central residues (K68, E69) of the fourth hypervariable loop of the Valpha domain (HV4alpha) in antigen recognition by an MHC class II-restricted T cell receptor (TCR) has been analyzed. The TCR recognizes the NH2-terminal peptide of myelin basic protein (Ac1-11, acetylated at NH2 terminus) associated with the class II MHC molecule I-Au. Lysine 68 (K68) and glutamic acid 69 (E69) of HV4alpha have been mutated both individually and simultaneously to alanine (K68A, E69A). The responsiveness of transfectants bearing wild-type and mutated TCRs to Ac1-11-I-Au complexes has been analyzed in the presence and absence of expression of the coreceptor CD4. The data demonstrate that in the absence of CD4 expression, K68 plays a central role in antigen responsiveness. In contrast, the effect of mutating E69 to alanine is less marked. CD4 coexpression can partially compensate for the loss of activity of the K68A mutant transfectants, resulting in responses that, relative to those of the wild-type transfectants, are highly sensitive to anti-CD4 antibody blockade. The observations support models of T cell activation in which both the affinity of the TCR for cognate ligand and the involvement of coreceptors determine the outcome of the T cell-antigen-presenting cell interaction. 相似文献
47.
An EMI estimate for shielding-enclosure evaluation 总被引:7,自引:0,他引:7
Min Li Drewniak J.L. Radu S. Nuebel J. Hubing T.H. DuBroff R.E. van Doren T.P. 《Electromagnetic Compatibility, IEEE Transactions on》2001,43(3):295-304
A relatively simple, closed-form expression has been developed to estimate the EMI from shielding enclosures due to coupling from interior sources through slots and apertures at the enclosure cavity modes. A power-balance method, Bethe's (1944) small-hole theory, and empirically developed formulas for the relation between radiation, and slot length and number of slots, were employed to estimate an upper bound on the radiated EMI from shielding enclosures. Comparisons between measurements and estimated field strengths suitably agree within engineering accuracy 相似文献
48.
Bogdan Bucur Gabriel Lucian Radu Constantin Nicolae Toader 《European Food Research and Technology》2008,226(6):1335-1342
A portable bienzymatic analytical system was developed for the chronoamperometric analysis of methanol–ethanol mixtures. The
system consists of two biosensors, one based on alcohol dehydrogenase (ADH) that responds only to the ethanol and the second
one based on alcohol oxidase (AOX) that responds to both methanol and ethanol. The transducers were screen-printed electrodes
(SPEs) modified with mediators: Meldola blue for ADH and Co-phthalocyanine for AOX. The calibration graph of the ADH biosensor
is linear between 0.3 and 8 mmol/L ethanol. The AOX biosensor is able to quantify both analytes in mixtures that contain methanol
between 3 and 70 mmol/L and ethanol ranging from 15 to 110 mmol/L. Interferences due to non-specific oxidations from common
oxidizable compounds like gallic acid and ascorbic acid were smaller in the case of transducer based on Meldola blue. The
analytical system was successfully tested on real samples: non-alcoholised beer (NAB) spiked with ethanol or methanol and
a falsified rose wine (FRW). 相似文献
49.
Placement of Substrate Contacts to Minimize Substrate Noise in Mixed-Signal Integrated Circuits 总被引:1,自引:0,他引:1
Radu M. Secareanu Scott Warner Scott Seabridge Cathie Burke Thomas E. Watrobski Christopher Morton William Staub Thomas Tellier Eby G. Friedman 《Analog Integrated Circuits and Signal Processing》2001,28(3):253-264
The placement of substrate contacts in epi and non-epi technologies is analyzed in order to control and reduce the substrate noise amplitude and spreading. The choice of small or large substrate contacts or rings for each of the two major technologies is highlighted. Design guidelines for placing substrate contacts so as to improve the noise immunity of digital circuits in mixed-signal smart-power systems are also presented. 相似文献
50.
Prevalence and resistance to antibiotics for Aeromonas species from retail fish in Malaysia 总被引:1,自引:0,他引:1
A total of 87 market fish samples representing five types of fish were evaluated for the presence of Aeromonas spp. Of the samples examined, 69%, 55%, 11.5% and 2.3% harbored Aeromonas spp., A. veronii biovar sobria, A. hydrophila and A. caviae, respectively. The 60 isolated Aeromonas spp. strains were further examined for hemolytic activity, resistance to antimicrobial agents and presence of plasmids. Hemolytic activity varied widely among the isolated strains. Though all the isolates demonstrated resistance to three or more of the antibiotics tested, all were susceptible to ceptazidime. Thirty-four (56.7%) of the sixty isolates harbored plasmids, with sizes ranging from 2.3 to 15.7 kb. These results indicate that hemolytic, multiple antibiotic resistant and genetically diverse aeromonads are easily recovered from fish in this region. 相似文献