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1.
《Displays》2015
Multi-projector displays allow the realization of large and immersive projection environments by allowing the tiling of projections from multiple projectors. Such tiled displays require real time geometrical warping of the content that is being projected from each projector. This geometrical warping is a computationally intensive operation and is typically applied using high-end graphics processing units (GPUs) that are able to process a defined number of projector channels. Furthermore, this limits the applicability of such multi-projector display systems only to the content that is being generated using desktop based systems. In this paper we propose a platform independent FPGA based scalable hardware architecture for geometric correction of projected content that allows addition of each projector channel at a fractional increase in logic area. The proposed scheme provides real time correction of HD quality video streams and thus enables the use of this technology for embedded and standalone devices. 相似文献
2.
Thirty patients who had undergone either a right or left unilateral temporal lobectomy (14 RTL; 16 LTL) and 16 control participants were tested on a computerized human analogue of the Morris Water Maze. The procedure was designed to compare allocentric and egocentric spatial memory. In the allocentric condition, participants searched for a target location on the screen, guided by object cues. Between trials, participants had to walk around the screen, which disrupted egocentric memory representation. In the egocentric condition, participants remained in the same position, but the object cues were shifted between searches to prevent them from using allocentric memory. Only the RTL group was impaired on the allocentric condition, and neither the LTL nor RTL group was impaired on additional tests of spatial working memory or spatial manipulation. The results support the notion that the right anterior temporal lobe stores long-term allocentric spatial memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
Wesley W. Chu Ph.D. Ion T. leong Ph.D. Ricky K. Taira Ph.D. 《The VLDB Journal The International Journal on Very Large Data Bases》1994,3(4):445-477
We introduce a semantic data model to capture the hierarchical, spatial, temporal, and evolutionary semantics of images in pictorial databases. This model mimics the user's conceptual view of the image content, providing the framework and guidelines for preprocessing to extract image features. Based on the model constructs, a spatial evolutionary query language (SEQL), which provides direct image object manipulation capabilities, is presented. With semantic information captured in the model, spatial evolutionary queries are answered efficiently. Using an object-oriented platform, a prototype medical-image management system was implemented at UCLA to demonstrate the feasibility of the proposed approach. 相似文献
4.
The paper describes a prototype system called HiSQL (Historical SQL) which extends the functionality of SQL in manipulating
historical data, by providing functions for spatial and temporal processing. Conceptually the paper is divided into three
parts: the first part deals with the design and architecture of the system; the second part introduces a case study (the defters);
and the third part describes specific functions for spatial and temporal processing of serial documents. The paper concludes
with a comparison between HiSQL and SQL and suggestions for further work.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
任意曲线透视投影的逆变换 总被引:1,自引:0,他引:1
透视曲线的逆变换是透视图象三维逆变换的重要基础。本文在给出透视投影逆变换基本方程的基础上,分别提出了圆、椭圆、二次曲线、任意平面曲线的透视投影逆变换的解析方法或计算机反求方法。同时给出灭点信息不足明图象的透视参数的准确反求方法。 相似文献
6.
金永杰 《核电子学与探测技术》1989,9(1):10-17
本文所提出的投影域重建——再投影迭代算法可以恢复不完整的扇形束投影数据,从而实现从有限的投影数据重建图象。这种算法把滤波——反投影图象重建过程和再投影的过程纳入一个公式,仅在投影域上估算未知的投影数据,因此避免了重建过程和反投影过程中的插值运算,改善了收敛性,提高了计算精度,缩短了运算时间。模拟实验表明:即使有70%的投影数据丢失,经过两次迭代就能以令人满意的精度恢复丢失的投影数据。 相似文献
7.
To examine the separate effects of viscosity and sweetness on astringency, aqueous solutions of grape seed tannin (GST) were thickened with carboxymethyl cellulose (CMC) from 2 to 45 cP (experiment 1) or sweetened with 0 to 1.8 g/L aspartame (experiment 2). Trained subjects continuously rated astringency and bitterness in duplicate. Subjects were categorized by the salivary flow induced by citric acid and ability to taste n-propyl thiouracil (PROP). In experiment 1, maximum intensity and total duration of astringency were significantly decreased as viscosity rose, although time to maximum intensity of astringency was not affected. Maximum intensity and total duration of bitterness were not significantly affected by increasing viscosity; however, the onset of bitterness was significantly delayed. In experiment 2, increasing sweetness had no affect on any astringency parameter, although maximum intensity of bitterness was significantly decreased. Neither PROP nor salivary flow-status had any effect on perception of bitterness or astringency in either experiment. 相似文献
8.
对《任意曲线透视投影的逆变换》中作出的以下3项研究结果进行了探讨并提出了不同见解:(1)透视投影的逆变换基本方程;(2)根据长方体上一个矩形的投影确定其长宽高之比;(3)由实体的透视图象准确重建其三维信息。 相似文献
9.
TheSpecial Issue on Applications of Temporal Models raises many issues of time: What are the important properties of time? How can time be best represented? How can one reason about time-dependent properties? What are the important directions of temporal research? This introductory piece very briefly surveys the current wide variety of temporal models, temporal reasoning methods, and applications to time-varying phenomena. Promising areas of investigation such as the verification of concurrent systems, knowledge-base representation methods, and dealing with theFrame Problem pass in fleeting review. Brief introductions to each of the works in the volume close the section. 相似文献
10.