方差阴影图中的光渗现象消除算法

方差阴影图算法使用概率的方法计算像素被遮挡的上限概率,通过对深度图滤波的方法来有效地减少阴影图算法中的走样问题,但在深度比较复杂的场景中方差阴影图算法会出现光渗现象,即在应该是阴影的区域却有了亮度.文中使用最小-最大阴影图来辅助消除方差阴影图中的光渗现象,在对深度纹理进行滤波的同时生成一个最小-最大阴影图;在实时绘制场景时,利用最小-最大阴影图来辅助判断当前片元是否完全处在阴影区域内部,由此生成更真实、更准确的阴影.该算法可以很容易地添加到已有的方差阴影图算法的片元处理程序中,并且不会对原有阴影的柔和边界以及绘制的帧率产生影响.

基于GPU的近似软影实时绘制

通过对阴影图算法进行扩展,提出一种完全基于GPU的近似软影实时绘制算法,它是一种3遍算法:第一遍从光源中心计算场景的深度图;第二遍采用几何着色器提取物体的轮廓边,同时在轮廓边上生成新的几何图元,利用硬件自动插值功能向外绘制线性近似半影图,并根据第一遍得到的深度图在像素着色器中对背面轮廓形成的半影区进行剔除;对于重叠的半影区设定片元的伪深度值,利用硬件进行自动融合.第三遍分别查询深度图和半影图,确定场景的本影区以及半影区中像素的亮度,从而得到面光源照射下场景的近似软影效果.

Total-internal-reflection fluorescence microscopy with W-shaped axicon mirrors

A scheme based on a W-shaped axicon mirror device for total-internal-reflection fluorescence microscopy (TIRFM) is presented. This approach combines the advantages of higher efficiency compared with traditional TIRFM, adjustable illumination area, and simple switching between wide-field and TIRF imaging modes. TIRF images obtained with this approach are free of shadow artifacts and of interference fringes. Example micrographs of fluorescently labeled polystyrene beads, of Convallaria majalis tissue, and of Propidium-iodide-labeled Chinese hamster ovary cells are shown, and the capabilities of the scheme are discussed. (C) 2010 Optical Society of America

基于阴影图的伪柔和阴影绘制算法

本文提出一种基于阴影图预滤波的伪柔和阴影实时绘制算法。 阴影是真实世界中的一种十分普遍的物理现象，它不但可以反映物体自身的形状，而且可以反映空间中物体与物体之间的相对位置关系，对于增加场景的真实感具有非常重要的意义。因而阴影的实时绘制一直都是计算机图形学中一个重要的研究方向。 方差阴影图算法是对传统阴影图算法的一个重要改进。传统的阴影图算法虽然有着易于实现、硬件支持好、与场景复杂度无关等优点，但是由于它是对场景的离散表示，所以会出现各种各样的走样问题。方差阴影图算法是使用概率的方法计算片元被遮挡的上限概率，它可以通过对深度图滤波的方法来有效地减少阴影图算法中的走样问题。方差阴影图算法克服了传统阴影图算法中边界走样问题，可以生成比较柔和的边界。但是，这种概率方法在深度比较复杂的场景中会出现光渗现象，即在原本应该是阴影的区域却有了亮度。本文使用最小-最大阴影图来辅助消除方差阴影图中的光渗现象。算法在对深度纹理进行滤波的同时生成一个最小-最大阴影图；在从视点实时绘制场景时，利用最小-最大阴影图来辅助判断当前片元是否完全处在阴影区域内部。通过将最小-最大阴影图和方差阴影图相结合，本文的算法可以快速生成伪柔和阴影。

Undercut structures fabricated by microtransfer printing combined with UV exposure and their applications

In this paper. the undercut structures were fabricated by microtransfer printing of metal films on the surface of photoresist combined with UV exposure and photoresist film developing. The patterned metal films were used as mask to realize the selective UV exposure of photoresist Firstly. The undercut structures. which consist of the top metal films and the patterned bottom photoresist, formed in the subsequent developing process because of the lateral dissolving of photoresist at the edge of the unexposed regions. The method proposed in this paper has wider tolerance to the changing of the patterning parameters. but, without effect on patterning resolution since the metal film was used as the top layer. The undercut Structures were Used as separators to pattern passive-matrix display of organic light-emitting diodes (OLEDs). No visible difference of the device performance was observed Compared with the OLEDs patterned by the shadow mask.

用光学阵列传感器的机器人物体分类系统

本文介绍用光学阵列传感器的机器人物体分类系统。传感器直接安装在机器人的两个手指上。被抓物体的阴影通过光导纤维传到安放在“安全区”的光敏元件上。计算机识别物体的轮廓后命令机器人抓握物体,并把它运送到指定的地点从而达到物体分类的目的。

Generating Semantic Descriptions From Drawings of Scenes With Shadows

The research reported here concerns the principles used to automatically generate three-dimensional representations from line drawings of scenes. The computer programs involved look at scenes which consist of polyhedra and which may contain shadows and various kinds of coincidentally aligned scene features. Each generated description includes information about edge shape (convex, concave, occluding, shadow, etc.), about the type of illumination for each region (illuminated, projected shadow, or oriented away from the light source), and about the spacial orientation of regions. The methods used are based on the labeling schemes of Huffman and Clowes; this research provides a considerable extension to their work and also gives theoretical explanations to the heuristic scene analysis work of Guzman, Winston, and others.

Reading Lydgate's Troy Book: patronage, politics, and history in Lancastrian England

This thesis, Reading Lydgate's Troy Book: Patronage, Politics and History in Lancastrian England, discusses the relationship between John Lydgate as a court poet to his patron Henry V. I contend that the Troy Book is explored as a vehicle to propagate the idea that the House of Lancaster is the legitimate successor to King Richard II in order to smooth over the usurpation of 1399. Paul Strohm's England's Empty Throne was a key influence to the approach of this thesis' topic. I examine that although Chaucer had a definitive impact on Lydgate's writing, Lydgate is able to manipulate this influence for his own ambitions. In order to enhance his own fame, Lydgate works to promote Chaucer's canon so that as Chaucer's successor, he will inherit more prestige. The Trojan war is seen in context with the Hundred Years War, and can be applied contextually to political events. Lydgate presents characters that are vulnerable to human failings, and their assorted, complicated relationships. Lydgate modernises the Troy Book to reflect and enhance his Lancastrian society, and the thesis gives a contextual view of Lydgate's writing of the Troy Book. Lydgate writes for a more varied target audience than his thirteenth-century source, Guido delle Colonne, and there is a deliberation on the female characters of the Troy Book which promulgates the theory that Lydgate takes a proactive and empathetic interest in women's roles in society. Furthermore Lydgate has never really been accepted as a humanist, and I look at Lydgate's work from a different angle; he is a self-germinating humanist. Lydgate revives antiquity to educate his fifteenth-century audience, and his ambition is to create a memorial for his patron in the vernacular, and enhance his own fame as a poet separate from Chaucer's shadow.

VISION OF EQUINOX FOR ORCHESTRA

The artistic play of light seen on a pyramid in some Mayan ruins located in Cancun, Mexico provided the inspiration for Vision of Equinox. On both the spring and autumn equinox days, the sunlight projected on the pyramid forms a shape which looks like a serpent moving on the stairway of the pyramid. Vision of Equinox was composed with an image of light as the model for the artistic transfiguration of sound. The light image of sound changes its shape in each stage of the piece, using the orchestra in different ways - sometimes like a chamber ensemble, sometimes like one big instrument. The image of light casting on a pyramid is expressed by descending melodic lines that can be heard several times in the piece. At the final climax of the work, a complete and embodied artistic figure is formed and stated, expressing the appearance of the Mayan god Quetzalcoatl, the serpent, in my own imagination. The light and shadow which comprise this pyramid art are treated as two contrasting elements in my composition and become the two main motives in this piece. To express these two contrasting elements, I picked the numbers "5" and "2," and used them as "key numbers" in this piece. As a result, the intervals of a fifth and a second (sometimes inverted as a seventh) are the two main intervals used in the structure. The interval of a fifth was taken into account for the construction of the pyramid, which has five points of contact. The interval of a second was selected as a contrasting sonority to the fifth. Further, the numbers "5" and "2" are used as the number of notes which form the main motives in this piece; quintuplets are used throughout this piece, and the short motive made by two sixteenth notes is used as one of the main motives in this piece. Moreover, the shape of the pyramid provided a concept of symmetry, which is expressed by the setting of a central point of the music (pitch center) as well as the use of retrograde and inversion in this piece.

Seeing the forest for the fuel

We demonstrate a new approach to understanding the role of fuelwood in the rural household economy by applying insights from travel cost modeling to author-compiled household survey data and meso-scale environmental statistics from Ruteng Park in Flores, Indonesia. We characterize Manggarai farming households' fuelwood collection trips as inputs into household production of the utility yielding service of cooking and heating. The number of trips taken by households depends on the shadow price of fuelwood collection or the travel cost, which is endogenous. Econometric analyses using truncated negative binomial regression models and correcting for endogeneity show that the Manggarai are 'economically rational' about fuelwood collection and access to the forests for fuelwood makes substantial contributions to household welfare. Increasing cost of forest access, wealth, use of alternative fuels, ownership of kerosene stoves, trees on farm, park staff activity, primary schools and roads, and overall development could all reduce dependence on collecting fuelwood from forests. © 2004 Cambridge University Press.

Exploration of the Kuiper Belt by High-Precision Photometric Stellar Occultations: First Results

We report here the first detection of hectometer-size objects by the method of serendipitous stellar occultation. This method consists of recording the diffraction shadow created when an object crosses the observer's line of sight and occults the disk of a background star. One of our detections is most consistent with an object between Saturn and Uranus. The two other diffraction patterns detected are caused by Kuiper Belt objects beyond 100 AU from the Sun and hence are the farthest known objects in the solar system. These detections show that the Kuiper Belt is much more extended than previously believed and that the outer part of the disk could be composed of smaller objects than the inner part. This gives critical clues to understanding the problem of the formation of the outer planets of the solar system.

De la cooperativa agroalimentaria a la "learning netchain". Hacia un planteamiento teorico interorganizativo e interpersonal

Se propone un planteamiento teórico/conceptual para determinar si las relaciones interorganizativas e interpersonales de la netchain de las cooperativas agroalimentarias evolucionan hacia una learning netchain. Las propuestas del trabajo muestran que el mayor grado de asociacionismo y la mayor cooperación/colaboración vertical a lo largo de la cadena están positivamente relacionados con la posición horizontal de la empresa focal más cercana del consumidor final. Esto requiere una planificación y una resolución de problemas de manera conjunta, lo que está positivamente relacionado con el mayor flujo y diversidad de la información/conocimiento obtenido y diseminado a lo largo de la netchain. Al mismo tiempo se necesita desarrollar un contexto social en el que fluya la información/conocimiento y las nuevas ideas de manera informal y esto se logra con redes personales y, principalmente, profesionales y con redes internas y, principalmente, externas. Todo esto permitirá una mayor satisfacción de los socios de la cooperativa agroalimentaria y de sus distribuidores y una mayor intensidad en I+D, convirtiéndose la netchain de la cooperativa agroalimentaria, así, en una learning netchain.

A Slaveholders' Republic in the Tumult of War

Review essay of recent work on wartime disaffection in the southern Confederacy: Stephanie McCurry's award-winning _Confederate Reckoning_ and Victorian Bynum's _Long Shadow of the Civil War_. Includes a broader assessment of recent historiography, state of the field.

Evaluation of corneal endothelium and keratic precipitates by specular microscopy in anterior uveitis

Background - The study of corneal endothelium, by specular microscopy, in patients with anterior uveitis has largely been restricted to observations on the endothelial cells. In this prospective study 'keratic precipitates' (KP) in different types of uveitis were examined in different stages of the disease process and the endothelial changes occurring in the vicinity of the KP were evaluated in comparison with the endothelium of the uninvolved eye. Methods - 13 patients with active unilateral uveitis were recruited. The mean age was 42.9 years (range 20-76 years). A Tomey-1100 contact wide field specular (x10) microscope was used to capture endothelial images and KP until the resolution of uveitis. Data regarding type of uveitis, number, size, and nature of KP were recorded. Automated morphometric analysis was done for cell size, cell density and coefficient of variation, and statistical comparisons of cell size and cell density were made (Student's t test) between the endothelium in the vicinity of fresh and resolving KP, fresh KP and normal endothelium, and resolving KP and normal endothelium. Results - On specular microscopy, fresh KP were seen as dense, white glistening deposits occupying 5-10 endothelial cells in diameter and fine KP were widely distributed and were one or two endothelial cells in diameter. The KP in Posner-Schlossman syndrome had a distinct and different morphology. With clinical remission of uveitis, the KP were observed to undergo characteristic morphological changes and old KP demonstrated a large, dark halo surrounding a central white deposit and occasionally a dark shadow or a 'lacuna' replaced the site of the original KP. Endothelial blebs were noted as dark shadows or defects in the endothelial mosaic in patients with recurrent uveitis. There was significant statistical difference in the mean cell size and cell density of endothelial cells in the vicinity of fresh KP compared with normal endothelium of the opposite eye. Conclusion - This study elucidated the different specular microscopic features of KP in anterior uveitis. Distinct morphological features of large and fine KP were noted. These features underwent dramatic changes on resolution of uveitis. The endothelium was abnormal in the vicinity of KP, which returned to near normal values on resolution of uveitis.

'Dark Interpretations': Romanticism's Ambiguous Legacy in India

This essay argues that Romanticism’s legacy in modern Indian literature has been constructed under the shadow of its colonial heritage. Although the Romantic period witnessed the enthusiastic “discovery” of classical Indian literature by British Orientalists, Romantic imperialism (which went hand-in-hand with Romantic orientalism) played a darker role in instituting a colonial educational system in India which denigrated Indian languages and literatures. Modern Indian literature represented by popular fictional writers from R.K. Narayan to Arundhati Roy registers this complex colonial inheritance by its qualified and often ironic celebration of British Romantic literature along with its associated ideologies of freedom, truth, and beauty.