bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced Depth and Visual Hulls of Complex 3D Scenes
Authors: Bogomjakov Alexander , Gotsman Craig 
Published: April 2008

AbstractDepth and visual hulls are useful for quick reconstruction and rendering of a 3D object based on a number of reference views. However, for many scenes, especially multi‐object, these hulls may contain significant artifacts known as phantom geometry. In depth hulls the phantom geometry appears behind the scene objects in regions occluded from all the reference views. In visual hulls the phantom geometry may also appear in front of the objects because there is not enough information to unambiguously imply the object positions.In this work we identify which parts of the depth and visual hull might constitute phantom geometry. We define the notion of reduced depth hull and reduced visual hull as the parts of the corresponding hull that are phantom‐free. We analyze the role of the depth information in identification of the phantom geometry. Based on this, we provide an algorithm for rendering the reduced depth hull at interactive frame‐rates and suggest an approach for rendering the reduced visual hull. The rendering algorithms take advantage of modern GPU programming techniques.Our techniques bypass explicit reconstruction of the hulls, rendering the reduced depth or visual hull directly from the reference views.
Effect of Character Animacy and Preparatory Motion on Perceptual Magnitude of Errors in Ballistic Motion
Authors: Reitsma P. S. A. , Andrews J. , Pollard N. S. 
Published: April 2008

AbstractAn increasing number of projects have examined the perceptual magnitude of visible artifacts in animated motion. These studies have been performed using a mix of character types, from detailed human models to abstract geometric objects such as spheres. We explore the extent to which character morphology influences user sensitivity to errors in a fixed set of ballistic motions replicated on three different character types. We find user sensitivity responds to changes in error type or magnitude in a similar manner regardless of character type, but that users display a higher sensitivity to some types of errors when these errors are displayed on more human‐like characters. Further investigation of those error types suggests that being able to observe a period of preparatory motion before the onset of ballistic motion may be important. However, we found no evidence to suggest that a mismatch between the preparatory phase and the resulting ballistic motion was responsible for the higher sensitivity to errors that was observed for the most humanlike character.
CHC++: Coherent Hierarchical Culling Revisited
Authors: Mattausch Oliver , Bittner Jiří , Wimmer Michael 
Published: April 2008

AbstractWe present a new algorithm for efficient occlusion culling using hardware occlusion queries. The algorithm significantly improves on previous techniques by making better use of temporal and spatial coherence of visibility. This is achieved by using adaptive visibility prediction and query batching. As a result of the new optimizations the number of issued occlusion queries and the number of rendering state changes are significantly reduced. We also propose a simple method for determining tighter bounding volumes for occlusion queries and a method which further reduces the pipeline stalls. The proposed method provides up to an order of magnitude speedup over the previous state of the art. The new technique is simple to implement, does not rely on hardware calibration and integrates well with modern game engines.
Augmented Panoramic Video
Authors: Hermans C. , Vanaken C. , Mertens T. , Van Reeth F. , Bekaert P. 
Published: April 2008

AbstractMany video sequences consist of a locally dynamic background containing moving foreground subjects. In this paper we propose a novel way of re‐displaying these sequences, by giving the user control over a virtual camera frame. Based on video mosaicing, we first compute a static high quality background panorama. After segmenting and removing the foreground subjects from the original video, the remaining elements are merged into a dynamic background panorama, which seamlessly extends the original video footage. We then re‐display this augmented video by warping and cropping the panorama. The virtual camera can have an enlarged field‐of‐view and a controlled camera motion. Our technique is able to process videos with complex camera motions, reconstructing high quality panoramas without parallax artefacts, visible seams or blurring, while retaining repetitive dynamic elements.
Zippy: A Framework for Computation and Visualization on a GPU Cluster
Authors: Fan Zhe , Qiu Feng , Kaufman Arie E. 
Published: April 2008

AbstractDue to its high performance/cost ratio, a GPU cluster is an attractive platform for large scale general‐purpose computation and visualization applications. However, the programming model for high performance general‐purpose computation on GPU clusters remains a complex problem. In this paper, we introduce the Zippy frame‐work, a general and scalable solution to this problem. It abstracts the GPU cluster programming with a two‐level parallelism hierarchy and a non‐uniform memory access (NUMA) model. Zippy preserves the advantages of both message passing and shared‐memory models. It employs global arrays (GA) to simplify the communication, synchronization, and collaboration among multiple GPUs. Moreover, it exposes data locality to the programmer for optimal performance and scalability. We present three example applications developed with Zippy: sort‐last volume rendering, Marching Cubes isosurface extraction and rendering, and lattice Boltzmann flow simulation with online visualization. They demonstrate that Zippy can ease the development and integration of parallel visualization, graphics, and computation modules on a GPU cluster.
Texture Synthesis From Photographs
Authors: Eisenacher C. , Lefebvre S. , Stamminger M. 
Published: April 2008

AbstractThe goal of texture synthesis is to generate an arbitrarily large high‐quality texture from a small input sample. Generally, it is assumed that the input image is given as a flat, square piece of texture, thus it has to be carefully prepared from a picture taken under ideal conditions. Instead we would like to extract the input texture from any surface from within an arbitrary photograph. This introduces several challenges: Only parts of the photograph are covered with the texture of interest, perspective and scene geometry introduce distortions, and the texture is non‐uniformly sampled during the capture process. This breaks many of the assumptions used for synthesis.In this paper we combine a simple novel user interface with a generic per‐pixel synthesis algorithm to achieve high‐quality synthesis from a photograph. Our interface lets the user locally describe the geometry supporting the textures by combining rational Bézier patches. These are particularly well suited to describe curved surfaces under projection. Further, we extend per‐pixel synthesis to account for arbitrary texture sparsity and distortion, both in the input image and in the synthesis output. Applications range from synthesizing textures directly from photographs to high‐quality texture completion.
Real‐Time Translucent Rendering Using GPU‐based Texture Space Importance Sampling
Authors: Chang Chih‐Wen , Lin Wen‐Chieh , Ho Tan‐Chi , Huang Tsung‐Shian , Chuang Jung‐Hong 
Published: April 2008

AbstractWe present a novel approach for real‐time rendering of translucent surfaces. The computation of subsurface scattering is performed by first converting the integration over the 3D model surface into an integration over a 2D texture space and then applying importance sampling based on the irradiance stored in the texture. Such a conversion leads to a feasible GPU implementation and makes real‐time frame rate possible. Our implementation shows that plausible images can be rendered in real time for complex translucent models with dynamic light and material properties. For objects with more apparent local effect, our approach generally requires more samples that may downgrade the frame rate. To deal with this case, we decompose the integration into two parts, one for local effect and the other for global effect, which are evaluated by the combination of available methods [DS03, MKB* 03a] and our texture space importance sampling, respectively. Such a hybrid scheme is able to steadily render the translucent effect in real time with a fixed amount of samples.
Image‐based Aging Using Evolutionary Computing
Authors: Hubball Daniel , Chen Min , Grant Phil W. 
Published: April 2008

AbstractAging has considerable visual effects on the human face and is difficult to simulate using a universally‐applicable global model. In this paper, we focus on the hypothesis that the patterns of age progression (and regression) are related to the face concerned, as the latter implicitly captures the characteristics of gender, ethnic origin, and age group, as well as possibly the person‐specific development patterns of the individual. We use a data‐driven framework for automatic image‐based facial transformation in conjunction with a database of facial images. We build a novel parameterized model for encoding age‐transformation in addition with the traditional model for face description. We utilize evolutionary computing to learn the relationship between the two models. To support this work, we also developed a new image warping algorithm based on non‐uniform radial basis functions (NURBFs). Evolutionary computing was also used to handle the large parameter space associated with NURBFs. In comparison with several different methods, it consistently provides the best results against the ground truth.
NEXUS BETWEEN HOUSING AND THE MACRO ECONOMY: THE HONG KONG CASE
Authors: HO LOK SANG , WONG GARY 
Published: April 2008

AbstractThis paper shows that, consistent with the ‘economic base’ theory, exports drive domestic consumption and domestic investment, but housing appears to serve as an important link between exports and domestic expenditures. Focusing on the Hong Kong economy, which is a small open economy with a big population, we found that exports and interest rates drive housing prices over a long period, while housing prices in turn drive domestic expenditures.
Screening for LRRK2 mutations in patients with Parkinson’s disease in Russia: identification of a novel LRRK2 variant
Authors: Pchelina S. N. , Yakimovskii A. F. , Emelyanov A. K. , Ivanova O. N. , Schwarzman A. L. , Singleton A. B. 
Published: April 2008

Background and purpose:  Mutations in LRRK2, encoding leucine‐rich repeat kinase 2 (or Dardarin), cause autosomal dominant Parkinson's disease (AdPD) and are also found in sporadic PD (sPD). To investigate the frequency of LRRK2 mutations in a sample of Russian PD patients.Methods:  We sequenced the complete coding region of LRRK2 in 65 patients with AdPD and in 30 patients with sPD. Furthermore, in 20 patients with AdPD and in 159 patients with sPD we screened several common LRRK2 mutations (G2019S, R1441C/G/H, I2012T and I2020T).Results:  Five AdPD patients had the LRRK2 G2019S mutation (5.9%, 5/85). In addition, we discovered a novel LRRK2 variant V1613A in a family with a tremor dominant form of AdPD; this variant was not present in controls. We identified two patients with LRRK2 mutations in sPD: one with the G2019S mutation (0.5; 1/189) and another with the previously described R1441C mutation (0,5; 1/189).Conclusions:  LRRK2 mutations are common amongst patients with PD in Russia. The results also show that the G2019S mutation is the most frequent. We identified one novel mutation in a functional region of LRRK2.
THE ANALYSIS OF EUROPEAN COMPANY ACCOUNTS
Authors: Clay J. P. 
Published: April 2008

SUMMARYNumerous details have been given here of the faults (in English eyes) to be found in European accounts, and of the progress that is being made towards overcoming them; but the greatest obstacle to progress is undoubtedly psychological—the failure of many in the financial world to realize that it is desirable for accounts to be accurate, comprehensive and clear. At Courchevel the European analysts discussed with interest the normal English auditors' report, whch attests that the accompanying accounts give ‘a true and fair view’; one remarked admiringly, ‘The English bring sport into everything: even a shareholder must have a fair chance, as though he were a fox’. This attitude, or somethmg like it, is becoming more widespread, but it is still far from universal; until it is more nearly so, it must be expected that progress will continue to be slow.
CUSTOMS UNIONS AND LATIN AMERICAN INTEGRATION
Authors: Griffin Keith , Ffrench‐Davis Ricardo 
Published: April 2008

SummaryThe potential gains from a customs union may be divided into two categories, those which improve the allocation of resources and those which lead to an increase in the quantity of available resources. The former are static, once‐for‐all gains, while the latter are cumulative gains. The static benefits can be represented as derived from changed price relationships along a fixed production frontier and as a movement to the frontier. The dynamic benefits of customs unions, on the other hand, lead to an increase in the rate of economic growth, and can be represented best by a series of shifts of the production frontier. The potential increase in welfare from improved resource allocation is likely to be small. The benefits from dynamic processes, as we try to demonstrate below, may be somewhat larger. Whether these potential benefits are translated into actual gains will depend upon whether the member countries are able to overcome certain problems of short‐run adjustment. There is no certainty they will be able to do this.
Antarctic terrestrial life – challenging the history of the frozen continent?
Authors: Convey Peter , Gibson John A. E. , Hillenbrand Claus‐Dieter , Hodgson Dominic A. , Pugh Philip J. A. , Smellie John L. , Stevens Mark I. 
Published: April 2008

AbstractAntarctica is a continent locked in ice, with almost 99.7% of current terrain covered by permanent ice and snow, and clear evidence that, as recently as the Last Glacial Maximum (LGM), ice sheets were both thicker and much more extensive than they are now. Ice sheet modelling of both the LGM and estimated previous ice maxima across the continent give broad support to the concept that most if not all currently ice‐free ground would have been overridden during previous glaciations. This has given rise to a widely held perception that all Mesozoic (pre‐glacial) terrestrial life of Antarctica was wiped out by successive and deepening glacial events. The implicit conclusion of such destruction is that most, possibly all, contemporary terrestrial life has colonised the continent during subsequent periods of glacial retreat. However, several recently emerged and complementary strands of biological and geological research cannot be reconciled comfortably with the current reconstruction of Antarctic glacial history, and therefore provide a fundamental challenge to the existing paradigms. Here, we summarise and synthesise evidence across these lines of research. The emerging fundamental insights corroborate substantial elements of the contemporary Antarctic terrestrial biota being continuously isolated in situ on a multi‐million year, even pre‐Gondwana break‐up timescale. This new and complex terrestrial Antarctic biogeography parallels recent work suggesting greater regionalisation and evolutionary isolation than previously suspected in the circum‐Antarctic marine fauna. These findings both require the adoption of a new biological paradigm within Antarctica and challenge current understanding of Antarctic glacial history. This has major implications for our understanding of the key role of Antarctica in the Earth System.
Neurogenic development of the visual areas in the Chinese softshell turtle (Pelodiscus sinensis) and evolutionary implications
Authors: Xi Chao , Zeng ShaoJu , Zhang XinWen , Zuo MingXue 
Published: April 2008

AbstractTo characterize the neurogenic development of the visual areas of the turtle (Pelodiscus sinensis) during embryogenesis, a single dose of [3H]‐thymidine (10 µCi) was injected into egg yolks from stages S11~12 to S21. At hatching, localization of [3H]‐thymidine incorporation was examined, and led to three main observations. (1) Neurogenesis occurred in the stratum griseum centrale of the tectum opticum from S11~12 to S16 with a peak at S12. No obvious gradients of neurogenesis were observed. (2) Neurogenesis in the nucleus rotundus (Rot) and in the dorsal lateral geniculate nucleus (GLd) occurred from S11~12 to S15. Gradients of neurogenesis were detected along ventral–dorsal and lateral–medial axes in the Rot, but only the latter neurogenic gradient occurred in the GLd. (3) In the visual region of the dorsal ventricular ridge, neurogenesis lasted from S11~12 to S16. Similarly, neurogenesis occurred from S11~12 to S16~17 in the dorsal cortex, with a peak at S12 for both telencephalic visual regions. Neurogenesis followed a ventrolateral to dorsomedial gradient in the visual region of the dorsal ventricular ridge, and a superficial to deep gradient in the caudal dorsal cortex. A significant number of neurons in the rostral dorsal cortex followed a deep (earlier arising) to superficial (later arising) pattern of neurogenesis, similar to that in the avian Wulst or in the mammalian isocortex. Finally, we compared the timing and development of neurogenesis in the turtle with birds and mammals to understand the evolutionary implications of these processes.
The optic vesicle promotes cornea to lens transdifferentiation in larval Xenopus laevis
Authors: Cannata Stefano M. , Bernardini Sergio , Filoni Sergio , Gargioli Cesare 
Published: April 2008

AbstractThe outer cornea and pericorneal epidermis (lentogenic area) of larval Xenopus laevis are the only epidermal regions competent to regenerate a lens under the influence of the retinal inducer. However, the head epidermis of the lentogenic area can acquire the lens‐regenerating competence following transplantation of an eye beneath it. In this paper we demonstrate that both the outer cornea and the head epidermis covering a transplanted eye are capable of responding not only to the retinal inducer of the larval eye but also to the inductive action of the embryonic optic vesicle by synthesizing crystallins. As the optic vesicle is a very weak lens inductor, which promotes crystallin synthesis only on the lens biased ectoderm of the embryo, these results indicate that the lens‐forming competence in the outer cornea and epidermis of larval X. laevis corresponds to the persistence and acquisition of a condition similar to that of the embryonic biased ectoderm.
The lens‐regenerating competence in the outer cornea and epidermis of larval Xenopus laevis is related to pax6 expression
Authors: Gargioli Cesare , Giambra Vincenzo , Santoni Sara , Bernardini Sergio , Frezza Domenico , Filoni Sergio , Cannata Stefano M. 
Published: April 2008

AbstractAfter lentectomy, larval Xenopus laevis can regenerate a new lens by transdifferentiation of the outer cornea and pericorneal epidermis (lentogenic area). This process is promoted by retinal factor(s) accumulated into the vitreous chamber. To understand the molecular basis of the lens‐regenerating competence (i.e. the capacity to respond to the retinal factor forming a new lens) in the outer cornea and epidermis, we analysed the expression of otx2, pax6, sox3, pitx3, prox1, βB1‐cry (genes all involved in lens development) by Real‐time RT‐PCR in the cornea and epidermis fragments dissected from donor larvae. The same fragments were also implanted into the vitreous chamber of host larvae to ascertain their lens‐regenerating competence using specific anti‐lens antibodies. The results demonstrate that there is a tight correlation between lens‐regenerating competence and pax6 expression. In fact, (1) pax6 is the only one of the aforesaid genes to be expressed in the lentogenic area; (2) pax6 expression is absent in head epidermis outside the lentogenic area and in flank epidermis, both incapable of transdifferentiating into lens after implantation into the vitreous chamber; (3) in larvae that have undergone eye transplantation under the head or flank epidermis, pax6 re‐expression was observed only in the head epidermis covering the transplanted eye. This is consistent with the fact that only the head epidermis reacquires the lens‐regenerating competence after eye transplantation, forming a lens following implantation into the vitreous chamber; and (4) in larvae that have undergone removal of the eye, the epidermis covering the orbit maintained pax6 expression. This is consistent with the fact that after the eye enucleation the lentogenic area maintains the lens‐regenerating competence, giving rise to a lens after implantation into the vitreous chamber. Moreover, we observed that misexpression of pax6 is sufficient to promote the acquisition of the lens‐regenerating competence in flank epidermis. In fact, flank epidermis fragments dissected from pax6 RNA injected embryos could form lenses when implanted into the vitreous chamber. The data indicate for the first time that pax6 is a pivotal factor of lens‐regenerating competence in the outer cornea and epidermis of larval X. laevis.
Enhancing phytoremediation through the use of transgenics and endophytes
Authors: Doty Sharon Lafferty 
Published: April 2008

SummaryIn the last decade, there has been an increase in research on improving the ability of plants to remove environmental pollution. Genes from microbes, plants, and animals are being used successfully to enhance the ability of plants to tolerate, remove, and degrade pollutants. Through expression of specific bacterial genes in transgenic plants, the phytotoxic effects of nitroaromatic pollutants were overcome, resulting in increased removal of these chemicals. Overexpression of mammalian genes encoding cytochrome P450s led to increased metabolism and removal of a variety of organic pollutants and herbicides. Genes involved in the uptake or detoxification of metal pollutants were used to enhance phytoremediation of this important class of pollutants. Transgenic plants containing specific bacterial genes converted mercury and selenium to less toxic forms. In addition to these transgenic approaches, the use of microbes that live within plants, termed endophytes, also led to improved tolerance to normally phytotoxic chemicals and increased removal of the pollutants. Bacteria that degraded a herbicide imparted resistance to the herbicide when inoculated into plants. In another study, plants harboring bacteria capable of degrading toluene were more tolerant to normally phytotoxic concentrations of the chemical, and transpired less of it into the atmosphere. This review examines the recent advances in enhancing phytoremediation through transgenic plant research and through the use of symbiotic endophytic microorganisms within plant tissues.ContentsSummary318I.Remediation of environmental contaminants via engineering and biological methods319II.Phytoremediation with transgenics322III.Endophyte‐assisted phytoremediation326IV.Concluding remarks329Acknowledgements329References329