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排序方式: 共有189条查询结果,搜索用时 15 毫秒
1.
Husain Syed Sameed Ong Eng-Jon Bober Miroslaw 《International Journal of Computer Vision》2021,129(5):1432-1450
International Journal of Computer Vision - We propose a novel CNN architecture called ACTNET for robust instance image retrieval from large-scale datasets. Our key innovation is a learnable... 相似文献
2.
A. Bernasik J. Janowski W. Hirschwald F. Stolze J. Nowotny 《Journal of Materials Science》1991,26(9):2527-2532
Surface segregation of various impurities such as Mg, Si, Ca, Al and Cr were determined for the haematite phase (Fe2O3) annealed in two different gas compositions involving (1) air at 1173 K, and (2) a gas mixture containing sulphur at 773 K. The objective of work was to establish the effect of the gas-phase composition on segregation of lattice defects. The near-surface segregation profiles of the impurities were determined by secondary ion mass spectrometry. The depth profile analysis was made by sputtering using an Ar+ primary beam of energy 30 keV. The surface charge was neutralized by an electron gun. It was found that annealing Fe2O3 under a gas phase containing sulphur resulted in the formation of an Fe(SO4)3 surface layer. It was observed that the two surface treatment procedures applied (both with and without sulphur) result in Mg enrichment in the near-surface region of Fe2O3. Si and Ca exhibit an enrichment and impoverishment after the surface treatments 1 and 2, respectively. Finally, the near-surface layer is impoverished in Cr and Al after both types of surface treatment. Experimental results are discussed in terms of segregation driving forces of the respective elements and the possible effect of sulphur on the gas-solid heterogeneous kinetics. 相似文献
3.
The cognitive exhaustion model of helplessness (predicting withdrawal from constructive effortful processing after uncontrollability) was applied to decision making. After unsolvable problems (or no preexposure), Ss requested information from a matrix with 5 alternatives (films)?×?10 attributes and then chose the best film. Films in a set were either similar (difficult decision) or dissimilar (easy decision) in attractiveness. As predicted, Ss with an uncontrollable preexposure spent less time on predecisional information search, disregarded their own importance criteria when asking for information, and had attention highly focused on a selected option for the easy decision condition but diffused across options for the difficult decision condition. The implications of these findings for understanding cognitive mechanisms of learned helplessness and depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
A mesoporous two-phase system, consisting of colloidal silica in the cavities of the main silica frame work of a macroporous glass, was investigated by use of Small-Angle X-ray scattering. The transformed correlation function T(r) was determined for this material for distances r<40 nm. The application of the intrinsic properties of T(r) yields estimations for two fundamental order distances L
1=11 nm and L
2=120 nm of the~porous glass possessing a clear geometric interpretation: L
1, a short-order-range, is the mean chord length of the mesopores plus the mean chord length in the secondary particles. L
2, a long-order-range, is an estimation of the mean diameter of a macropore plus the mean free distance in the silica framework which separates two nearly parallel segments of two adjacent macropores. 相似文献
5.
Lucjan Janowski Piotr Kozłowski Remigiusz Baran Piotr Romaniak Andrzej Glowacz Tomasz Rusc 《Multimedia Tools and Applications》2014,68(1):23-40
Video transmission and analysis is often utilized in applications outside of the entertainment sector, and generally speaking this class of video is used to perform specific tasks. Examples of these applications include security and public safety. The Quality of Experience (QoE) concept for video content used for entertainment differs significantly from the QoE of surveillance video used for recognition tasks. This is because, in the latter case, the subjective satisfaction of the user depends on achieving a given functionality. Recognizing the growing importance of video in delivering a range of public safety services, we focused on developing critical quality thresholds in license plate recognition tasks based on videos streamed in constrained networking conditions. Since the number of surveillance cameras is still growing it is obvious that automatic systems will be used to do the tasks. Therefore, the presented research includes also analysis of automatic recognition algorithms. 相似文献
6.
Predicting weekly defect inflow in large software projects based on project planning and test status
Defects discovered during the testing phase in software projects need to be removed before the software is shipped to the customers. The removal of defects can constitute a significant amount of effort in a project and project managers are faced with a decision whether to continue development or shift some resources to cope with defect removal. The goal of this research is to improve the practice of project management by providing a method for predicting the number of defects reported into the defect database in the project. In this paper we present a method for predicting the number of defects reported into the defect database in a large software project on a weekly basis. The method is based on using project progress data, in particular the information about the test progress, to predict defect inflow in the next three coming weeks. The results show that the prediction accuracy of our models is up to 72% (mean magnitude of relative error for predictions of 1 week in advance is 28%) when used in ongoing large software projects. The method is intended to support project managers in more accurate adjusting resources in the project, since they are notified in advance about the potentially large effort needed to correct defects. 相似文献
7.
The stereologic analysis of a solid grain has been applied for determination of its porosity. The investigations were carried out on a natural hematite grain reduced to magnetite at 723 K. Stereologic analysis enabled the porosity of this material to be determined on the basis of independently measured grain contours and volume fractions of grain components: hematite, magnetite and pores. A conformity criterion has been formulated, regarding determination of grain volume on the basis of known densities of components and their measured volume fractions in the grain, and on the basis of weight and apparent grain density measurements. The volume increase accompanying reduction of hematite to magnetite, determined from these independent measurements, was in the range 7–19%. By measuring Ferets diameter, the volume of the convex envelope of the grain increased as a result of phase transformation by about 11%. Simultaneously, the volume of the solid phase was found to decrease by 1.5%. The total porosity of the reduced grain, determined by stereologic analysis amounted to 17.5%; 7.7% of which was related to cracks and large pores, and 9.8% to small pores in the magnetite phase. The porosity value determined by the classical mercury method was approximately the same. 相似文献
8.
Miroslaw Staron Wilhelm Meding Christer Nilsson 《Information and Software Technology》2009,51(4):721-737
As in every engineering discipline, metrics play an important role in software development, with the difference that almost all software projects need the customization of metrics used. In other engineering disciplines, the notion of a measurement system (i.e. a tool used to collect, calculate, and report quantitative data) is well known and defined, whereas it is not as widely used in software engineering. In this paper we present a framework for developing custom measurement systems and its industrial evaluation in a software development unit within Ericsson. The results include the framework for designing measurement systems and its evaluation in real life projects at the company. The results show that with the help of ISO/IEC standards, measurement systems can be effectively used in software industry and that the presented framework improves the way of working with metrics. This paper contributes with the presentation of how automation of metrics collection and processing can be successfully introduced into a large organization and shows the benefits of it: increased efficiency of metrics collection, increased adoption of metrics in the organization, independence from individuals and standardized nomenclature for metrics in the organization. 相似文献
9.
Marcin Bienkowski Marek Klonowski Miroslaw Korzeniowski Dariusz R. Kowalski 《Distributed Computing》2016,29(5):341-359
In this paper we consider the mutual exclusion problem on a multiple access channel. Mutual exclusion is one of the fundamental problems in distributed computing. In the classic version of this problem, n processes execute a concurrent program that occasionally triggers some of them to use shared resources, such as memory, communication channel, device, etc. The goal is to design a distributed algorithm to control entries and exits to/from the shared resource (also called a critical section), in such a way that at any time, there is at most one process accessing it. In our considerations, the shared resource is the shared communication channel itself (multiple access channel), and the main challenge arises because the channel is also the only mean of communication between these processes. We consider both the classic and a slightly weaker version of mutual exclusion, called \(\varepsilon \)-mutual-exclusion, where for each period of a process staying in the critical section the probability that there is some other process in the critical section is at most \(\varepsilon \). We show that there are channel settings, where the classic mutual exclusion is not feasible even for randomized algorithms, while the \(\varepsilon \)-mutual-exclusion is. In more relaxed channel settings, we prove an exponential gap between the makespan complexity of the classic mutual exclusion problem and its weaker \(\varepsilon \)-exclusion version. We also show how to guarantee fairness of mutual exclusion algorithms, i.e., that each process that wants to enter the critical section will eventually succeed. 相似文献
10.
Immigration and Construction: The Makeup of the Workforce in the Washington, D.C., Metropolitan Area
There are an estimated 11 million illegal immigrants currently residing in the United States. Of this population, research shows that approximately 19% work in the construction industry, comprising around 14% of all construction workforces. The Washington, D.C. metropolitan region has a unique makeup of workforces within the construction industry. Between September 2006 and February 2007, 896 construction workers from several projects in the Washington, D.C. metropolitan area participated in a survey. The study targeted the low-skilled, immigrant-saturated trades in construction. The most compelling finding in this study was that illegal immigrants make up a far greater proportion of the construction workers in low-skilled trades than indicated by national averages, 55% as compared to between 20 and 36% nationally. This will increase the impact of immigration and immigration reform substantially for the Washington, D.C. metropolitan. 相似文献