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排序方式: 共有75条查询结果,搜索用时 15 毫秒
11.
Boolean algebra is the basic mathematic used in the analysis and synthesis of binary systems. Technological advances have led to an increasing interest in multivalued logic systems where more than two logical values are used.In the application of multivalued logic, each logical value could often be represented by a Boolean vector, ie a vector with binary components (0 or 1). Therefore, it is quite important to have a thorough understanding of properties embedded in the algebraic structures using Boolean vectors as basic operands. This gives the motivation for this study.Boolean vector operations are introduced and two major modes associated with the complement are characterized. Then we define a Boolean vector E-algebra and its major features are given. Finally, some applications are discussed and illustrated. 相似文献
12.
In this paper, we propose a new error concealment (EC) method using inter‐layer correlation for scalable video coding. In the proposed method, the auxiliary motion vector (MV) and the auxiliary mode number (MN) of intra prediction are interleaved into the bitstream to recover the corrupted frame. In order to reduce the bit rate, the proposed method encodes the difference between the original and the predicted values of the MV and MN instead of the original values. Experimental results show that the proposed EC outperforms the conventional EC by 2.8 dB to 6.7 dB. 相似文献
13.
Kuen-Fang JeaAuthor Vitae Tsui-Ping ChangAuthor Vitae Chia-Wen ChengAuthor Vitae 《Computer Standards & Interfaces》2011,33(3):280-291
In this paper we propose a generic simulation model, named XSM, with which researchers can construct standard platforms and evaluate their proposed concurrency control protocols for native XDBMSs. The system environment, the performance metrics, and the protocol rules of various types of XML protocols are all considered by the model. To facilitate the implementation of XSM, the state diagrams, the sequence diagrams, the component diagram, and the class diagram of XSM are depicted using UML 2.0 notations. We also show a simulation platform constructed from XSM to fairly and comprehensively evaluate the performance of various XML protocols. 相似文献
14.
Zhang H Yang F Qian WJ Brown RN Wang Y Merkley ED Merkley EE Park JH Monroe ME Purvine SO Moore RJ Shi L Fredrickson JK Paša-Tolić L Smith RD Lipton MS 《Analytical chemistry》2011,83(19):7260-7268
The c-type cytochromes play essential roles in many biological activities of both prokaryotic and eukaryotic cells, including electron transfer, enzyme catalysis, and induction of apoptosis. We report a novel enrichment strategy for identifying c-type heme-containing peptides that uses nonactivated IMAC resin. The strategy demonstrated at least 7-fold enrichment for heme-containing peptides digested from a cytochrome c protein standard, and quantitative linear performance was also assessed for heme-containing peptide enrichment. Heme-containing peptides extracted from the periplasmic fraction of Shewanella oneidensis MR-1 were further identified using higher-energy collisional dissociation tandem mass spectrometry. The results demonstrated the applicability of this enrichment strategy to identify c-type heme-containing peptides from a highly complex biological sample and, at the same time, confirmed the periplasmic localization of heme-containing proteins during suboxic respiration activities of S. oneidensis MR-1. 相似文献
15.
A simulation model for adsorption kinetics of hen egg white lysozyme (HEW) adsorption to hydrophilic silica is proposed. The
adsorption kinetic data were monitored by usingin-situ ellipsometry. The model is based on an irreversible adsorption mechanism allowing two different adsorbed states. The adsorbed
states were differentiated based on binding strengths resistant to the concentration gradient exerted by rinse. Molecules
desorbing and remaining upon rinse were identified as loosely bound (state 1) and tightly bound (state 2) states, respectively.
The adsorption rate constants were assumed to be a time-dependent nonlinear function in order to account for the change in
surface properties originating from the protein layer formed on the surface. The parameters of adsorption rate constants were
evaluated by using adsorption kinetic data at different protein concentrations, and the relationships between the adsorption
parameters and protein concentration were established which eventually demonstrated a linear relationship. The established
relations between the adsorption parameters and concentration elucidated the effect of protein concentration on adsorption
to hydrophilic silica. 相似文献
16.
Younghoon Kim Fanglin Che Jea Woong Jo Jongmin Choi F. Pelayo García de Arquer Oleksandr Voznyy Bin Sun Junghwan Kim Min‐Jae Choi Rafael Quintero‐Bermudez Fengjia Fan Chih Shan Tan Eva Bladt Grant Walters Andrew H. Proppe Chengqin Zou Haifeng Yuan Sara Bals Johan Hofkens Maarten B. J. Roeffaers Sjoerd Hoogland Edward H. Sargent 《Advanced materials (Deerfield Beach, Fla.)》2019,31(17)
Colloidal nanocrystals combine size‐ and facet‐dependent properties with solution processing. They offer thus a compelling suite of materials for technological applications. Their size‐ and facet‐tunable features are studied in synthesis; however, to exploit their features in optoelectronic devices, it will be essential to translate control over size and facets from the colloid all the way to the film. Larger‐diameter colloidal quantum dots (CQDs) offer the attractive possibility of harvesting infrared (IR) solar energy beyond absorption of silicon photovoltaics. These CQDs exhibit facets (nonpolar (100)) undisplayed in small‐diameter CQDs; and the materials chemistry of smaller nanocrystals fails consequently to translate to materials for the short‐wavelength IR regime. A new colloidal management strategy targeting the passivation of both (100) and (111) facets is demonstrated using distinct choices of cations and anions. The approach leads to narrow‐bandgap CQDs with impressive colloidal stability and photoluminescence quantum yield. Photophysical studies confirm a reduction both in Stokes shift (≈47 meV) and Urbach tail (≈29 meV). This approach provides a ≈50% increase in the power conversion efficiency of IR photovoltaics compared to controls, and a ≈70% external quantum efficiency at their excitonic peak. 相似文献
17.
Hyune‐Jea Lee Robert C. Roberts Do Jin Im Se‐Jun Yim Heejin Kim Ji Tae Kim Dong‐Pyo Kim 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(50)
High‐resolution 3D‐printed stainless steel metal microreactors (3D‐PMRs) with different cross‐sectional geometry are fabricated to control ultrafast intramolecular rearrangement reactions in a comparative manner. The 3D‐PMR with circular channel demonstrates the improved controllability in rapid Fries‐type rearrangement reactions, because of the superior mixing efficiency to rectangular cross‐section channels (250 µm × 125 µm) which is confirmed based on the computational flow dynamics simulation. Even in case of very rapid intramolecular rearrangement of sterically small acetyl group occurring in 333 µs of reaction time, the desired intermolecular reaction can outpace to the undesired intramolecular rearrangement using 3D‐PMR to result in high conversion and yield. 相似文献
18.
A near-optimal database allocation for reducing the average waiting time in the grid computing environment 总被引:1,自引:0,他引:1
In a grid computing environment, a great many users may access the same database simultaneously. To reduce the average waiting time for all users, a grid designer usually replicates the frequently accessed database among nodes based on the load balance heuristic. On the other hand, users may raise identical queries regarding an issue of interest, e.g., stock information, on a database and each of the queries will be directed to any node having a replica of that database. That is, the same answer will be determined by multiple nodes. Consequently, there exist two shortcomings of poor data sharing and duplicate calculations if the database is not replicated and allocated adequately. In this paper, we aim to minimize average waiting time and try to overcome the two shortcomings by performing database allocation over multiple nodes without any replication. The main idea behind the proposed method is to map the original problem to the Euclidean space Rn and to solve the mapped problem in Rn by a gradient-based optimization technique. The theoretical analyses ensure that the proposed method can converge linearly and achieve near-optimal results. 相似文献
19.
20.
Jea Hyeok Ryu Bo Gun Park Seuk Buom Kim Yong Joon Park 《Journal of Applied Electrochemistry》2009,39(7):1059-1066
The effect of surface area on the electrochemical properties and thermal stability of Li[Ni0.2Li0.2Mn0.6]O2 powders was characterized using a charge/discharge cycler and DSC (Differential Scanning Calorimeter). The surface area of
the samples was successfully controlled from ~4.0 to ~11.7 m2 g−1 by changing the molar ratio of the nitrate/acetate sources and adding an organic solvent such as acetic acid or glucose.
The discharge capacity and rate capability was almost linearly increased with increase in surface area of the sample powder.
A sample with a large surface area of 9.6–11.7 m2 g−1 delivered a high discharge capacity of ~250 mAh g−1 at a 0.2 C rate and maintained 62–63% of its capacity at a 6 C rate versus a 0.2 C rate. According to the DSC analysis, heat
generation by thermal reaction between the charged electrode and electrolyte was not critically dependent on the surface area.
Instead, it was closely related to the type of organic solvent employed in the fabrication process of the powder. 相似文献