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排序方式: 共有1671条查询结果,搜索用时 31 毫秒
31.
Jun Zhang Xianghong Liu Giovanni Neri Nicola Pinna 《Advanced materials (Deerfield Beach, Fla.)》2016,28(5):795-831
Sensor technology has an important effect on many aspects in our society, and has gained much progress, propelled by the development of nanoscience and nanotechnology. Current research efforts are directed toward developing high‐performance gas sensors with low operating temperature at low fabrication costs. A gas sensor working at room temperature is very appealing as it provides very low power consumption and does not require a heater for high‐temperature operation, and hence simplifies the fabrication of sensor devices and reduces the operating cost. Nanostructured materials are at the core of the development of any room‐temperature sensing platform. The most important advances with regard to fundamental research, sensing mechanisms, and application of nanostructured materials for room‐temperature conductometric sensor devices are reviewed here. Particular emphasis is given to the relation between the nanostructure and sensor properties in an attempt to address structure–property correlations. Finally, some future research perspectives and new challenges that the field of room‐temperature sensors will have to address are also discussed. 相似文献
32.
Thomas Reitmaier Nicola J. Bidwell Gary Marsden 《International journal of human-computer studies》2011,69(10):658-668
We reflect on the methods, activities and perspectives we used to situate digital storytelling in two rural African communities in South Africa and Kenya. We demonstrate how in-depth ethnography in a village in the Eastern Cape of South Africa and a design workshop involving participants from that village allowed us to design a prototype mobile digital storytelling system suited to the needs of rural, oral users. By leveraging our prototype as a probe and observing villagers using it in two villages in South Africa and Kenya, we uncovered implications for situating digital storytelling within those communities. Finally, we distil observations relevant to localizing storytelling and their implications for transferring design into a different community. 相似文献
33.
Rocco De Nicola 《Science of Computer Programming》2010,75(6):376-397
Coordination languages are often used to describe open-ended systems. This makes it challenging to develop tools for guaranteeing the security of the coordinated systems and the correctness of their interaction. Successful approaches to this problem have been based on type systems with dynamic checks; therefore, the correctness properties cannot be statically enforced. By contrast, static analysis approaches based on Flow Logic usually guarantee properties statically. In this paper, we show how the insights from the Flow Logic approach can be used to construct a type system for statically ensuring secure access to tuple spaces and safe process migration for an extension of the language Klaim. 相似文献
34.
35.
Some applications require autonomous robots to search an initially unknown environment for static targets, without any a priori information about environment structure and target locations. Targets can be human victims in search and rescue or materials
in foraging. In these scenarios, the environment is incrementally discovered by the robots exploiting exploration strategies
to move around in an autonomous and effective way. Most of the strategies proposed in literature are based on the idea of
evaluating a number of candidate locations on the frontier between the known and the unknown portions of the environment according
to ad hoc utility functions that combine different criteria. In this paper, we show some of the advantages of using a more theoretically-grounded
approach, based on Multi-Criteria Decision Making (MCDM), to define exploration strategies for robots employed in search and
rescue applications. We implemented some MCDM-based exploration strategies within an existing robot controller and we evaluated
their performance in a simulated environment. 相似文献
36.
Sergio Saponara Nicola E. L’Insalata Luca Fanucci 《Microprocessors and Microsystems》2009,33(3):191-200
The paper presents an automated environment for fast design space exploration and automatic generation of FFT/IFFT macrocells with minimum circuit and memory complexity within the numerical accuracy budget of the target application. The effectiveness of the tool is demonstrated through FPGA and CMOS implementations (90 nm, 65 nm and 45 nm technologies) of the baseband processing in embedded OFDM transceivers. Compared with state-of-art FFT/IFFT IP cores, the proposed work provides macrocells with lower circuit complexity while keeping the same system performance (throughput, transform size and accuracy) and is the first addressing the requirements of all OFDM standards including MIMO systems: 802.11 WLAN, 802.16 WMAN, Digital Audio and Video Broadcasting in terrestrial, handheld and hybrid satellite-scenarios, Ultra Wide Band, Broadband on Power Lines, xDSL. 相似文献
37.
Nicola M. Dring 《Computers in human behavior》2009,25(5):1089-1101
The body of empirical research on Internet sexuality has grown steadily since 1993. The following paper provides an overview of the current state of research in this field in its full thematic breadth, addressing six areas of online sexuality: Pornography, sex shops, sex work, sex education, sex contacts, and sexual subcultures. Key research results are presented concerning Internet sexuality’s forms of manifestation, participant groups, opportunities, and risks. This paper shows that sexually related online activities have become routine in recent years for large segments of the population in the Western world. Internet sexuality also takes somewhat different forms based on the age, gender, and sexual orientation of the individual. Academic studies to date have focused overwhelmingly on the possible negative effects of Internet sexuality. By contrast, little research has been conducted on potential benefits. Consequently, a surprising number of gaps are evident in the scholarship on Internet sexuality. 相似文献
38.
Enrico Giunchiglia Nicola Leone Marco Maratea 《Annals of Mathematics and Artificial Intelligence》2008,53(1-4):169-204
In this paper, we study the relation among Answer Set Programming (ASP) systems from a computational point of view. We consider smodels, dlv, and cmodels ASP systems based on stable model semantics, the first two being native ASP systems and the last being a SAT-based system. We first show that smodels, dlv, and cmodels explore search trees with the same branching nodes (assuming, of course, a same branching heuristic) on the class of tight logic programs. Leveraging on the fact that SAT-based systems rely on the deeply studied Davis–Logemann–Loveland (dll) algorithm, we derive new complexity results for the ASP procedures. We also show that on nontight programs the SAT-based systems are computationally different from native procedures, and the latter have computational advantages. Moreover, we show that native procedures can guarantee the “correctness” of a reported solution when reaching the leaves of the search trees (i.e., no stability check is needed), while this is not the case for SAT-based procedures on nontight programs. A similar advantage holds for dlv in comparison with smodels if the “well-founded” operator is disabled and only Fitting’s operator is used for negative inferences. We finally study the “cost” of achieving such advantages and comment on to what extent the results presented extend to other systems. 相似文献
39.
Enver Sangineto Nicola Capuano Matteo Gaeta Alessandro Micarelli 《Universal Access in the Information Society》2008,7(1-2):1-23
This paper presents an approach to automatic course generation and student modeling. The method has been developed during
the European funded projects Diogene and Intraserv, focused on the construction of an adaptive e-learning platform. The aim
of the platform is the automatic generation and personalization of courses, taking into account pedagogical knowledge on the
didactic domain as well as statistic information on both the student’s knowledge degree and learning preferences. Pedagogical
information is described by means of an innovative methodology suitable for effective and efficient course generation and
personalization. Moreover, statistic information can be collected and exploited by the system in order to better describe
the student’s preferences and learning performances. Learning material is chosen by the system matching the student’s learning
preferences with the learning material type, following a pedagogical approach suggested by Felder and Silverman. The paper
discusses how automatic learning material personalization makes it possible to facilitate distance learning access to both
able-bodied and disabled people. Results from the Diogene and Intraserv evaluation are reported and discussed. 相似文献
40.
Design optimization of an enzymatic assay in an electrokinetically-driven microfluidic device 总被引:1,自引:1,他引:0
Y. T. Atalay P. Verboven S. Vermeir N. Vergauwe F. Delport B. M. Nicolaï J. Lammertyn 《Microfluidics and nanofluidics》2008,5(6):837-849
Microfluidic systems are increasingly popular for rapid and cheap determinations of enzyme assays and other biochemical analysis.
In this study reduced order models (ROM) were developed for the optimization of enzymatic assays performed in a microchip.
The model enzyme assay used was β-galactosidase (β-Gal) that catalyzes the conversion of Resorufin β-d-galactopyranoside (RBG) to a fluorescent product as previously reported by Hadd et al. (Anal Chem 69(17): 3407–3412, 1997). The assay was implemented in a microfluidic device as a continuous flow system controlled electrokinetically and with a
fluorescence detection device. The results from ROM agreed well with both computational fluid dynamic (CFD) simulations and
experimental values. While the CFD model allowed for assessment of local transport phenomena, the CPU time was significantly
reduced by the ROM approach. The operational parameters of the assay were optimized using the validated ROM to significantly
reduce the amount of reagents consumed and the total biochip assay time. After optimization the analysis time would be reduced
from 20 to 5.25 min which would also resulted in 50% reduction in reagent consumption. 相似文献