虚拟环境下的实时自助照相技术

虚拟现实技术作为面向21世纪的新技术，是计算机图形学、人机接口技术、传感器技术以及人工智能技术等交叉与综合的结果。针对虚拟现实技术在照相领域中的应用空白，提出了虚拟环境下的实时自助照相技术，讨论了该技术所涉及到的虚拟现实、视频截取等关键性问题，详细介绍了在系统开发中提出的一种新算法：基于对比度感知特征的图像融合技术。     

人工生育方式的法律思考

能够生育自己的子女是每个已婚成年人的美好愿望,自己的子女是克隆的自己,自己的子女可以说是自己生命的延续,然而由于种种原因,某些已婚的成年人却无法通过自然而然的方式生育自己的子女,不过值得庆幸的是,随着社会经济的高度发达,人类科学技术的提高,一种新的生育方式出现了,也就是人工生育方式,人工生育方式为一些无法自然生育的人们提供拥有自己亲生子女的权利,人工生育的优势已无可否认,很多国家都已立法确定这一生育方式.但在具体的实施过程中却存在着很多问题.本文从法律的角度出发,结合我国人工生育的实际情况,论述了人工生育的方式、对人工生育的主体的思考、人工生育子女知情权的保障等问题.     

基于自然特征的增强现实注册算法

增强现实标志点注册算法需在场景中叠加各种标志,系统构造复杂.文中在深入研究机器人视觉伺服系统的基础上,提出了利用虚拟视觉伺服技术、基于自然特征的增强现实注册算法.利用特征点和图像矩作为图像特征,推导出了图像特征变化量与虚拟摄像机相对位姿变化量之间的关系矩阵(即图像的雅可比矩阵),实现了基于自然特征的三维注册算法.与混合跟踪注册算法、共面四点注册算法相比,文中方法具有更高的精度.     

A study on neural mechanism of face processing based on fMRI

Recently, there were debates about the specificity of lateral middle fuisform in face processing. The debates focused on whether these areas were specialized in face processing or involved in processing of visual expertise and categorization at individual level. The present study aims to investigate the neural mechanism of face processing, using Chinese characters as comparison stimuli. Chinese characters are greatly similar to faces on a variety of dimensions, among which the most significant one is that both faces and Chinese characters not only are extremely familiar to literate Chinese adults but also are processed at individual level. In the present study, faces and Chinese characters activated bilateral middle fusiform with great correlation. Greater activities were observed in the right fusiform face area (FFA) for faces than for Chinese characters. These results demonstrate that FFA is specialized in face processing per se rather than the processing of visual expertise and categorization at individual level.     

A study on neural mechanism of face processing based on fMRI

Recently, there were debates about the specificity of lateral middle fusiform in face processing. The debates focused on whether these areas were specialized in face processing or involved in processing of visual expertise and categorization at individual level. The present study aims to investigate the neural mechanism of face processing, using Chinese characters as comparison stimuli. Chinese characters are greatly similar to faces on a variety of dimensions, among which the most significant one is that both faces and Chinese characters not only are extremely familiar to literate Chinese adults but also are processed at individual level. In the present study, faces and Chinese characters activated bilateral middle fusiform with great correlation. Greater activities were observed in the right fusiform face area （FFA） for faces than for Chinese characters. These results demonstrate that FFA is specialized in face processing per se rather than the processing of visual expertise and categorization at individual level.     

The Evil of Human Nature in Lord of the Flies

William Golding is a very genuinely serious writer because he holds a very strong pessimistic view towards human nature.Lord of the Flies is Golding’s first novel.Especially,the novel shows the evil of human nature through little children.In the story,Golding puts those children in an isolated island,which far from the civilization world and without adults’control.The evil nature of human beings explored in the children without the rule of civilization.What’s more,Lord of the Flies is a novel which shows the original evil of human’s nature.We can learn some evil of human beings from Lord of the Flies as the same as reading Bible.My paper will analyze the evils contained in the novel through three steps.First,analyze main characters and symbol things in the novel.Second,analyze some important things or affaires in the novel.At last,find some more evils of human or society.     

基于船舶人机工程的虚拟人操作驱动建模仿真技术

针对船舶设计过程中复杂的人机工程学问题,提出了在虚拟环境中通过满足精度要求的虚拟人实时驱动模型仿真的新方法.采用动态约束方法,基于旋转信息建立虚拟人实时驱动模型,将运动跟踪系统捕获的真人运动参数映射到实时驱动模型而实现对不同百分位人体模型的操作;建立驱动误差模型,分析运动跟踪系统误差对实时驱动模型驱动精度的影响;基于上述方法开发了船舶虚拟人实时驱动模块,并集成到船舶产品设计的虚拟评估系统中;以某型船舶机舱设施布局的人机工程学评估为例进行应用验证.结果表明,所提出的虚拟人操作驱动模型具有较好的有效性.
     

Mapping multiple features in the population response of visual cortex

Stimulus features such as edge orientation, motion direction and spatial frequency are thought to be encoded in the primary visual cortex by overlapping feature maps arranged so that the location of neurons activated by a particular combination of stimulus features can be predicted from the intersections of these maps. This view is based on the use of grating stimuli, which limit the range of stimulus combinations that can be examined. We used optical imaging of intrinsic signals in ferrets to assess patterns of population activity evoked by the motion of a texture (a field of iso-oriented bars). Here we show that the same neural population can be activated by multiple combinations of orientation, length, motion axis and speed. Rather than reflecting the intersection of multiple maps, our results indicate that population activity in primary visual cortex is better described as a single map of spatiotemporal energy.     

基于无监督聚类算法的入侵检测

针对应用聚类方法检测入侵中参数人为指定的问题,提出了一种新的基于无监督的聚类算法.该方法不需要人为设置参数并且不受数据输入顺序的影响,聚类的形状是任意的,能够较真实地反映数据分布的具体性状.算法通过比较无类标训练集样本间的距离,根据距离最近的样本首先聚合成类的特性,在每一步聚类结束时,再次比较类间距离以及计算类内数据占总数据的比率来确定异常数据类.实验证明该算法处理未知入侵检测问题的检测率为89.5%,误报率为0.4%.     

真实感人体头部建模方法研究

在虚拟环境中，对人体头部变形曲面提取特征并参数化，建立基于弹簧质点系统的标准几何模型；借助重叠图像拼接技术形成纹理图像；根据纹理图像调整几何模型特征参数，配准图形和图像形成特定的变形几何模型，再把拼接图像纹理映射到变形几何模型上，得到一种真实感人体头部模型。     

虚拟漫游系统的研究

基于软件平台MultiGen Creator和Vega开发的虚拟场景漫游仿真系统．提出了视景节点的软硬件配置要求；论述了基于Creator的实体建模方法、基于Creator建模和Vega软件环境的天空效果生成方法、声音的调用、视景仿真软件的开发过程以及整体系统的实现等关键技术．仿真结果表明，该视景仿真系统逼真地演示出在虚拟场景中漫游的的过程，并且满足系统仿真的实时性要求．     

Instant neural control of a movement signal

The activity of motor cortex (MI) neurons conveys movement intent sufficiently well to be used as a control signal to operate artificial devices, but until now this has called for extensive training or has been confined to a limited movement repertoire. Here we show how activity from a few (7-30) MI neurons can be decoded into a signal that a monkey is able to use immediately to move a computer cursor to any new position in its workspace (14 degrees x 14 degrees visual angle). Our results, which are based on recordings made by an electrode array that is suitable for human use, indicate that neurally based control of movement may eventually be feasible in paralysed humans.     

Active tactile exploration using a brain-machine-brain interface

Brain-machine interfaces use neuronal activity recorded from the brain to establish direct communication with external actuators, such as prosthetic arms. It is hoped that brain-machine interfaces can be used to restore the normal sensorimotor functions of the limbs, but so far they have lacked tactile sensation. Here we report the operation of a brain-machine-brain interface (BMBI) that both controls the exploratory reaching movements of an actuator and allows signalling of artificial tactile feedback through intracortical microstimulation (ICMS) of the primary somatosensory cortex. Monkeys performed an active exploration task in which an actuator (a computer cursor or a virtual-reality arm) was moved using a BMBI that derived motor commands from neuronal ensemble activity recorded in the primary motor cortex. ICMS feedback occurred whenever the actuator touched virtual objects. Temporal patterns of ICMS encoded the artificial tactile properties of each object. Neuronal recordings and ICMS epochs were temporally multiplexed to avoid interference. Two monkeys operated this BMBI to search for and distinguish one of three visually identical objects, using the virtual-reality arm to identify the unique artificial texture associated with each. These results suggest that clinical motor neuroprostheses might benefit from the addition of ICMS feedback to generate artificial somatic perceptions associated with mechanical, robotic or even virtual prostheses.     

解析版式设计

在版式设计中，准确把握、合理运用文字、图形、色彩等视觉要素，达到内容与形式的完美结合，使版式设计真正成为视觉设计。     

虚拟人技术在人机交互中的应用研究

基于虚拟人的人机交互是人与虚拟现实环境中的虚拟人进行交互的技术。虚拟人是一种具有自主智能的看上去像人,并且具有人的部分特征的智能体。首先论述了虚拟人模型的构建技术、虚拟人的行为控制方法和虚拟人表情的构建和控制方法,然后论述了虚拟人在智能人机交互中的应用,最后探讨了虚拟人心智系统模型及虚拟人技术发展前景。     

基于数据融合的多生物特征身份识别

针对传统的单一生物特征身份识别由于传感器的噪音以及特征的破损、匹配等缺陷,往往不能正确识别的情况,提出了一种基于语音和人脸的多生物特征身份识别方法.分别提取语音特征和人脸特征作为识别的依据,并用神经网络在特征层上进行融合识别.实验证明,这种方法可以充分挖掘特征之间的关系,在同等条件下,具有更高的识别率.     

基于SGI平台的目标观测仿真研究

在研究Vega的基础上,采用虚拟仿真技术,通过模型对象在场景中的方位和属性设置,分析并确定模型的初始姿态,并通过对观察者使用栓系模式定位和分析,将观测者和目标角色对象进行绑定,成功地演示了目标观测的三种不同角度的视景仿真.该系统可以真实地模拟目标观测过程,提供了一个通用的仿真平台,可以大大降低虚拟视景仿真建模中的开发成本,并对同类虚拟仿真的研究也具有重要的指导意义.     

听障大学生造型意识的培养与绘画语言的发展

在高等特殊教育美术专业中科学、系统地培养听障生的造型意识,可提高其对视觉图象的观察能力、对视觉艺术语言的领悟能力、丰富的情感体验能力,并挖掘艺术潜力,使他们在作品中有想法,勇于表达自我,建立自信和完善人格,这在一定程度上可以拟补他们在生理上的不足,提高解决实际生活问题的能力。     

二维弹性薄体问题的虚边界元法

拓展了虚边界元方法的应用范围,将其应用于二维弹性薄体问题,避免了奇异边界积分和几乎奇异边界积分的计算.通过数值算例验证了虚、实边界的距离公式,公式的特点是距离与边界离散单元数有关,表明公式对于二维薄体结构同样适用.按照张耀明等虚边界元法的理论分析公式选择虚、实边界间的距离,即使结构狭窄到纳米级(10-9 m),依然可获得高精度的数值解.     

Altered Gs and adenylate cyclase activity in human GH-secreting pituitary adenomas

Gs and Gi are guanine nucleotide-binding, heterotrimer proteins that regulate the activity of adenylate cyclase, and are responsible for transferring stimulatory and inhibitory hormonal signals, respectively, from cell surface receptors to the enzyme catalytic unit. These proteins can be directly activated by agents such as GTP and analogues, fluoride and magnesium. Decreased amounts of Gs and Gi, and even the absence of Gs, have been described, whereas an altered Gs has been reported in a cultured cell line (UNC variant of S49 lymphoma cells), but has never been observed in human disease states. We have found a profoundly altered Gs protein in a group of human growth hormone-secreting pituitary adenomas, characterized by high secretory activity and intracellular cyclic AMP levels. In the membranes from these tumours no stimulation of adenylate cyclase activity by growth hormone-releasing hormone, by GTP or by fluoride was observed. Indeed, the last two agents caused an inhibition, probably mediated by Gi. In contrast, adenylate cyclase stimulation by Mg2+ was enormously increased. This altered pattern of adenylate cyclase regulation was reproduced when a cholate extract of the tumour membranes (which contains G proteins) was reconstituted with Gs-free, cyc- S49 cell membranes. Inasmuch as secretion from somatotrophic cells is known to be a cAMP-dependent function, the alteration of Gs could be the direct cause of the high secretory activity of the tumours in which it occurs.