排序方式: 共有46条查询结果,搜索用时 437 毫秒
1.
Mylène C. Q. Farias 《Journal of the Society for Information Display》2011,19(11):764-770
Abstract— In the past few years, a big effort in the scientific community has been devoted to the development of better image‐ and video‐quality metrics that correlate well with the human perception of quality. In this paper, an overview of the main ideas used in the design of objective quality metrics is given. More specifically, we briefly describe the different types of objective metrics and present a representative set of the different approaches taken by these algorithms. Finally, the challenges and recent developments in the area of image and video quality are discussed. 相似文献
2.
Most algorithms in probabilistic sampling-based path planning compute collision-free paths made of straight line segments lying in the configuration space. Due to the randomness of sampling, the paths make detours that need to be optimized. The contribution of this paper is to propose a basic gradient-based algorithm that transforms a polygonal collision-free path into a shorter one. While requiring only collision checking, and not any time-consuming obstacle distance computation nor geometry simplification, we constrain only part of the configuration variables that may cause a collision, and not entire configurations. Thus, parasite motions that are not useful for the problem resolution are reduced without any assumption. Experimental results include navigation and manipulation tasks, eg a manipulator arm-filling boxes and a PR2 robot working in a kitchen environment. Comparisons with a random shortcut optimizer and a partial shortcut have also been studied. 相似文献
3.
The influence of the supply on the cutting force is established in the machining of quenched steel by VOK-60 cutting ceramic. The optimal machining conditions for quenched 40Kh and KhVG steel workpieces are determined. 相似文献
4.
5.
This longitudinal study investigated the presence of a moderating effect of pregnancy planning on the relationship between marital status and parenting satisfaction of couples experiencing the transition to parenthood and verified whether this moderating effect is mediated by role overload. Data were collected from 150 Canadian couples during the 3rd trimester of pregnancy and at 9 months postpartum. Findings reveal that when the pregnancy is planned, the poorer parenting satisfaction reported by cohabiting fathers in comparison with their married counterparts can be explained by cohabiting men’s higher levels of role overload. Women’s levels of parenting satisfaction are also influenced by their own and their partner’s experiences of role overload. Results are discussed in terms of the respective values and lifestyles of cohabiting and married couples and specifically in terms of their different attitudes toward egalitarianism. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Russian Engineering Research - Technological approaches to digital transformation of industrial enterprises in the Fourth Industrial Revolution are considered. 相似文献
7.
Equations of the set of all possible rotations of the three-dimensional space (with both zero and nonzero centers) which translate the given initial point to the final one were obtained using the spinor representation of the orthogonal transformations of rotation. An equation of the plane where the centers of these rotations are situated was obtained. Relations between the elements of the complex unitary matrices of the second order and the real orthogonal rotation matrices of the third order as well as expressions for calculation of the Euler angles from the coordinates of the initial and final rotation points were derived. The latter play an important part in the control of spatial rotations of the mechanical plants.__________Translated from Avtomatika i Telemekhanika, No. 6, 2005, pp. 30–37.Original Russian Text Copyright © 2005 by Myl’nikov, Prangishvili, Rodonaya. 相似文献
8.
Sharp increases in food commodity prices in 2007–2008 led to impacts on food security and poverty worldwide. This paper discusses the impacts on smallholder farmers in six Arab countries that all suffer, to varying degrees, from water scarcity, poverty and food insecurity. The analysis is based on a survey covering more than 1000 rural households in Egypt, Jordan, Morocco, Sudan, Syria and Yemen. It examines government responses to the price spike, price transmission from international to local markets, and farmers’ production decisions in response to these price changes. It also discusses how smallholder farmers, given the right policy support, could benefit from new opportunities offered by higher commodity prices. Higher international prices were transmitted to domestic markets in all six countries. The price transmission was high and immediate in countries with the least intervention in food markets. In countries with more interventions on imports and/or domestic food prices, the connection between international and domestic prices was generally low. The ability of smallholder farmers to benefit from higher domestic prices was limited by various factors: drought, higher input prices (especially fertilizer), and the timing of the price increases in relation to the crop cycle. The study makes several recommendations to enable smallholder farmers to better respond to market signals. These include better timing of announcement of policy decisions regarding price supports, better access to credit, safety nets to protect the poorest households, improved management of water resources, and simple financial instruments to protect against price volatility. 相似文献
9.
10.
Russian Engineering Research - Practical approaches are described for introducing an energy management system at a high-tech enterprise so as to centralize and automate the regulation of energy... 相似文献