bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of Antibody Responses in West Nile Virus-Seropositive Blood Donors
Authors: Carson Paul J. , Prince Harry E. , Biggerstaff Brad J. , Lanciotti Robert , Tobler Leslie H. , Busch Michael
Published: October 2013

West Nile virus (WNV) is now endemic in the United States. Protection against infection is thought to be conferred in part by humoral immunity. An understanding of the durability and specificity of the humoral response is not well established. We studied the magnitude and specificity of antibody responses in 370 WNV-seropositive blood donors. We also recalled 18 donors who were infected in 2005 to compare their antibody responses at 6 months following infection versus at 5 years postinfection. There were no significant differences in IgG antibody levels based on age, sex, or recent infection (as evidenced by IgM positivity). Specific antibody responses by viral plaque reduction neutralization testing (PRNT) were seen in 51/54 subjects evaluated. All donors who were seropositive in 2005 remained seropositive at 5 years and maintained neutralizing antibodies. IgG levels at 5 years postinfection showed fairly minimal decreases compared with the paired levels at 6 months postinfection (mean of paired differences,−0.54 signal-to-cutoff ratio (S/CO) units [95% confidence interval {CI}, −0.86 to −0.21 S/CO units]) and only minimal decreases in PRNT titers. WNV induces a significant antibody response that remains present even 5 years after infection.
Evaluation of Agar-Based Medium with Sheep Sera for Testing of Drug Susceptibility of Mycobacterium tuberculosis to Isoniazid, Rifampin, Ethambutol, and Streptomycin
Authors: Coban Ahmet Yilmaz , Uzun Meltem , Bozdogan Bulent
Published: October 2013

The performance of sheep sera instead of sheep blood in agar-based media was investigated for susceptibility testing of
Mycobacterium tuberculosis
against primary drugs. The levels of agreement between agar-based medium supplemented with sheep sera and the proportion method on Middlebrook 7H11 agar as the reference method for determining susceptibility to isoniazid (INH), rifampin (RIF), ethambutol (EMB), and streptomycin (STR) were 98.4, 98.4, 95.3, and 100%, respectively.
Development of a Capillary Electrophoresis-Based Heteroduplex Tracking Assay To Measure In-Host Genetic Diversity of Initial and Recurrent Plasmodium vivax Infections in Cambodia
Authors: Givens Matthew B. , Lin Jessica T. , Lon Chanthap , Gosi Panita , Char Meng Chuor , Lanteri Charlotte A. , Saunders David L. , Juliano Jonathan J.
Published: October 2013

A heteroduplex tracking assay used to genotype
Plasmodium vivax
merozoite surface protein 1 was adapted to a capillary electrophoresis format, obviating the need for radiolabeled probes and allowing its use in settings where malaria is endemic. This new assay achieved good allelic discrimination and detected high multiplicities of infection in 63
P. vivax
infections in Cambodia. More than half of the recurrent parasitemias sampled displayed identical or highly related genotypes compared to the initial genotype, suggesting that they represented relapses.
Characterization of a Novel Betacoronavirus Related to Middle East Respiratory Syndrome Coronavirus in European Hedgehogs
Authors: Corman Victor Max , Kallies René , Philipps Heike , Göpner Gertraude , Müller Marcel Alexander , Eckerle Isabella , Brünink Sebastian , Drosten Christian , Drexler Jan Felix
Published: October 2013

Bats are known to host viruses closely related to important human coronaviruses (HCoVs), such as HCoV-229E, severe-acute respiratory syndrome coronavirus (SARS-CoV), and Middle East respiratory syndrome CoV (MERS-CoV). As RNA viruses may coevolve with their hosts, we sought to investigate the closest sister taxon to bats, the
Eulipotyphla
, and screened European hedgehogs (
Erinaceus europaeus
) from Germany for CoV by nested reverse transcriptase PCR. A novel betacoronavirus species in a phylogenetic sister relationship to MERS-CoV and clade c bat CoVs was detected and characterized on the whole-genome level. A total of 58.9% of hedgehog fecal specimens were positive for the novel CoV (EriCoV) at 7.9 log
10
mean RNA copies per ml. EriCoV RNA concentrations were higher in the intestine than in other solid organs, blood, or urine. Detailed analyses of the full hedgehog intestine showed the highest EriCoV concentrations in lower gastrointestinal tract specimens, compatible with viral replication in the lower intestine and fecal-oral transmission. Thirteen of 27 (48.2%) hedgehog sera contained non-neutralizing antibodies against MERS-CoV. The animal origins of this betacoronavirus clade that includes MERS-CoV may thus include both bat and nonbat hosts.
Chimeric Virus-Like Particle Vaccines Displaying Conserved Enterovirus 71 Epitopes Elicit Protective Neutralizing Antibodies in Mice through Divergent Mechanisms
Authors: Ye Xiaohua , Ku Zhiqiang , Liu Qingwei , Wang Xiaoli , Shi Jinping , Zhang Yunfang , Kong Liangliang , Cong Yao , Huang Zhong
Published: October 2013

Enterovirus 71 (EV71) is a major causative agent of hand, food, and mouth disease, which frequently occurs in young children. Since there are 11 subgenotypes (A, B1 to B5, and C1 to C5) within EV71, an EV71 vaccine capable of protecting against all of these subgenotypes is desirable. We report here the vaccine potential and protective mechanism of two chimeric virus-like particles (VLPs) presenting conserved neutralizing epitopes of EV71. We show that fusions of hepatitis B core antigen (HBc) with the SP55 or SP70 epitope of EV71, designated HBcSP55 and HBcSP70, respectively, can be rapidly generated and self-assembled into VLPs with the epitopes displayed on the surface. Immunization with the chimeric VLPs induced carrier- and epitope-specific antibody responses in mice. Anti-HBcSP55 and anti-HBcSP70 sera, but not anti-HBc sera, were able to neutralize
in vitro
multiple genotypes and strains of EV71. Importantly, passive immunization with anti-HBcSP55 or anti-HBcSP70 sera protected neonatal mice against lethal EV71 infections. Interestingly, anti-HBcSP70 sera could inhibit EV71 attachment to susceptible cells, whereas anti-HBcSP55 sera could not. However, both antisera were able to neutralize EV71 infection
in vitro
at the postattachment stage. The divergent mechanism of neutralization and protection conferred by anti-SP70 and anti-SP55 sera is in part attributed to their respective ability to bind authentic viral particles. Collectively, our study not only demonstrates that chimeric VLPs displaying the SP55 and SP70 epitopes are promising candidates for a broad-spectrum EV71 vaccine but also reveals distinct mechanisms of neutralization by the SP55- and SP70-targeted antibodies.
Residues Arg703, Asp777, and Arg781 of the RNase H Domain of Hepatitis B Virus Polymerase Are Critical for Viral DNA Synthesis
Authors: Ko Chunkyu , Shin Youn-Chul , Park Woo-Jin , Kim Seungtaek , Kim Jonghwa , Ryu Wang-Shick
Published: October 2013

Hepatitis B virus (HBV) synthesizes its DNA genome through reverse transcription, which is catalyzed by viral polymerase (Pol). Previous studies suggested that the RNase H domain of hepadnaviral Pol may contribute to multiple steps of the viral genome replication, such as RNA encapsidation and viral DNA synthesis. However, specific residues of the RNase H domain that contribute to viral reverse transcription have not been determined. Therefore, we employed charged-to-alanine scanning mutagenesis to generate a set of single-substitution mutants of the RNase H domain and then analyzed their ability to support viral reverse transcription. Southern blot analysis showed that three mutants (R703A, D777A, and R781A mutants) yielded significantly reduced amounts of viral DNAs. However, none of these mutants were defective in RNA encapsidation. The data indicated that in the R703A and D777A mutants, minus-strand DNA synthesis was incomplete due to loss of catalytic activity of RNase H. In contrast, in the R781A mutant, the minus-strand DNA synthesis was near complete to some extent, while the plus-strand DNA synthesis (i.e., relaxed circular DNA) was severely impaired due to the defect in RNase H activity. Overall, our analysis revealed that three charged residues of the HBV Pol RNase H domain contribute to the catalysis of RNase H in removing the RNA template, but not in the RNA encapsidation.
Both HLA-B*57 and Plasma HIV RNA Levels Contribute to the HIV-Specific CD8
+
T Cell Response in HIV Controllers
Authors: Lécuroux Camille , Sáez-Cirión Asier , Girault Isabelle , Versmisse Pierre , Boufassa Faroudy , Avettand-Fenoël Véronique , Rouzioux Christine , Meyer Laurence , Pancino Gianfranco , Lambotte Olivier , Sinet Martine , Venet Alain
Published: October 2013

CD8
+
T cell responses are thought to play an important role during HIV infection, particularly in HIV controllers (HIC) in whom viral replication is spontaneously controlled without any treatment. We have demonstrated that CD8
+
T cells from these subjects are able to suppress viral replication
in vitro
. In parallel, HIV-specific CD8
+
responses were shown to be strong and of high quality, with proliferative abilities and cytotoxic capacities, in HIC. The HLA-B*57 allele, which is associated with a better clinical outcome in HIV infection, is overrepresented in HIC. However, we showed that these patients constitute a heterogeneous group that includes subjects who present weak suppression of viral replication
in vitro
and HIV-specific responses. We performed an extensive study of 101 HIC (49 HLA-B*57
+
and 52 HLA-B*57
−
) to determine the impact of HLA-B*57 on the HIV-specific CD8
+
response. The HLA-B*57-restricted response displayed better qualitative features, such as higher functional avidity, higher proliferation capacity, and a higher level of cytokine production, than responses not restricted by HLA-B*57. However, the highest frequencies of HIV-specific CD8
+
T cells were observed only in a subset of HLA-B*57
+
subjects. They were tightly associated with the ability to suppress viral replication
in vitro
. In contrast, the subset of HLA-B*57
+
subjects with a weak ability to suppress viral replication had significantly lower ultrasensitive viral loads than all the other groups of controllers. In conclusion, both HLA-B*57 and the amount of ultrasensitive viral load seem to play a role in HIV-specific CD8
+
T cell responses in HIC.
Patient-initiated questions: How can doctors encourage them and improve the consultation process? A qualitative study
Authors: Murtagh G M , Furber L , Thomas A L
Published: October 2013

Objective

To investigate the circumstances under which patients initiate direct questions in oncology consultations.

Design

Conversation analysis of 47 consultations between oncologists and patients with cancer.

Setting

An oncology clinic at a teaching hospital in the East Midlands.

Participants

16 Oncologists and 67 cancer patients.

Outcome measure

Patient initiated direct questions.

Results

On the whole patients’ direct questions are designed to seek specific information regarding, the cancer itself, treatment options or their experience of symptoms. When patients do ask direct questions they typically follow the announcement of test results where some reference to the details of those results, is provided. More specifically, there seems to be a relation between showing the patient their scan/X-ray results, patient involvement and patient-initiated direct questions. Higher levels of patient-initiated direct questions were clustered around occasions where doctors provided information and explanations of test results (12 consultations) sometimes with direct reference to scan or X-ray results (7 consultations).

Conclusions

This study highlights the importance of careful explanation of diagnostic evidence as a factor contributing to increased patient involvement. More specifically, the findings suggest that, when appropriate, invoking diagnostic evidence (eg, scan or X-ray results) is an effective way of increasing levels of patient question asking. Doctors need to be able to encourage patient question asking to ensure that patients have at their disposal an important means through which they can determine their information needs. Although these results come from a study of oncology consultations, the findings may be transferable to other clinical contexts.
Spatial dynamics of the rise and fall of caribou (Rangifertarandus) in Newfoundland
Authors: Schaefer J.A. , Mahoney S.P.
Published: October 2013

Understanding the relationship between abundance and distribution is central to ecology but may require broad-scale observations, especially for long-lived, mobile animals like caribou (Rangifer tarandus (L., 1758)). We tested the link between demography and spatial ecology of Newfoundland caribou, coincident with their numerical growth (1980s, 1990s) and decline (2000s). We analysed site fidelity, rate of movements, timing of migration, and population organization from telemetry observations of more than 600 adult females. Site fidelity was consistent across herds, intensifying near the onset of calving and peaking in late summer, a cycle that may reflect selection for postpartum security. Late-summer fidelity was stronger in the 1980s than 1990s, a trend that reversed itself during the 2000s. Weekly movements were lower in the 2000s, but with no clear differences between the 1980s and 1990s. Timing of migration changed: in the 2000s, spring migration of the Buchans herd occurred 3 weeks earlier and autumn migration 3 weeks later compared with the previous decade, the reversal of a 40-year trend. Herd affinities, revealed by fuzzy membership coefficients, diminished by the 2000s. These changes are consistent with the hypothesis of limitation by summer forage competition. Space use represents a useful gauge of numerical changes in caribou.
GENERALIZED SYNCHRONIZATION OF NONIDENTICAL FRACTIONAL-ORDER CHAOTIC SYSTEMS
Authors: WANG XING-YUAN , HU ZUN-WEN , LUO CHAO
Published: October 2013

In this paper, a chaotic synchronization scheme is proposed to achieve the generalized synchronization between two different fractional-order chaotic systems. Based on the stability theory of fractional-order systems and the pole placement technique, a controller is designed and theoretical proof is given. Two groups of examples are shown to verify the effectiveness of the proposed scheme, the first one is to realize the generalized synchronization between the fractional-order Chen system and the fractional-order Rössler system, the second one is between the fractional-order Lü system and the fractional-order hyperchaotic Lorenz system. The corresponding numerical simulations verify the effectiveness of the proposed scheme.
Evolution of temporal multimedia synchronization principles
Authors: Huang Zixia , Nahrstedt Klara , Steinmetz Ralf
Published: October 2013

The evolution of multimedia applications has drastically changed human life and behaviors. New communication technologies lead to new requirements for multimedia synchronization. This article presents a historical view of temporal synchronization studies focusing on continuous multimedia. We demonstrate how the development of multimedia systems has created new challenges for synchronization technologies. We conclude with a new application-dependent, multilocation, multirequirement synchronization framework to address these new challenges.
Image search—from thousands to billions in 20 years
Authors: Zhang Lei , Rui Yong
Published: October 2013

This article presents a comprehensive review and analysis on image search in the past 20 years, emphasizing the challenges and opportunities brought by the astonishing increase of dataset scales from thousands to billions in the same time period, which was witnessed first-hand by the authors as active participants in this research area. Starting with a retrospective review of three stages of image search in the history, the article highlights major breakthroughs around the year 2000 in image search features, indexing methods, and commercial systems, which marked the transition from stage two to stage three. Subsequent sections describe the image search research from four important aspects: system framework, feature extraction and image representation, indexing, and big data's potential. Based on the review, the concluding section discusses open research challenges and suggests future research directions in effective visual representation, image knowledge base construction, implicit user feedback and crowdsourcing, mobile image search, and creative multimedia interfaces.
Over twenty years of eigenfaces
Authors: Turk Matthew
Published: October 2013

The inaugural ACM Multimedia Conference coincided with a surge of interest in computer vision technologies for detecting and recognizing people and their activities in images and video. Face recognition was the first of these topics to broadly engage the vision and multimedia research communities. The Eigenfaces approach was, deservedly or not, the method that captured much of the initial attention, and it continues to be taught and used as a benchmark over 20 years later. This article is a brief personal view of the genesis of Eigenfaces for face recognition and its relevance to the multimedia community.
Looking forward 10 years to multimedia successes
Authors: Rowe Lawrence A.
Published: October 2013

A panel at ACM Multimedia 2012 addressed research successes in the past 20 years. While the panel focused on the past, this article discusses successes since the ACM SIGMM 2003 Retreat and suggests research directions in the next ten years. While significant progress has been made, more research is required to allow multimedia to impact our everyday computing environment. The importance of hardware changes on future research directions is discussed. We believe ubiquitous computing—meaning abundant computation and network bandwidth—should be applied in novel ways to solve multimedia grand challenges and continue the IT revolution of the past century.
Are we in the middle of a video streaming revolution?
Authors: Swaminathan Viswanathan
Published: October 2013

It has been roughly 20 years since the beginning of video streaming over the Internet. Until very recently, video streaming experiences left much to be desired. Over the last few years, this has significantly improved making monetization of streaming, possible. Recently, there has been an explosion of commercial video delivery services over the Internet, sometimes referred to as over-the-top (OTT) delivery. All these services invariably use streaming technologies. Initially, streaming had all the promise, then for a long time, it was download and play, later progressive download for short content, and now it is streaming again. Did streaming win the download versus streaming contest? Did the best technology win? The improvement in streaming experience has been possible through a variety of new streaming technologies, some proprietary and others extensions to standard protocols. The primary delivery mechanism for entertainment video, both premium content like movies and user generated content (UGC), tends to be HTTP streaming. Is HTTP streaming the panacea for all problems? The goal of this article is to give an industry perspective of what fundamentally changed in video streaming that makes it commercially viable now. This article outlines how a blend of technology choices between download and streaming makes the current wave of ubiquitous streaming possible for entertainment video delivery. After identifying problems that still need to be solved, the article concludes with the lessons learnt from the video streaming evolution.
Multimedia retrieval that matters
Authors: Hanjalic Alan
Published: October 2013

This article emphasizes the need to refocus multimedia information retrieval (MIR) research towards bridging the
utility gap
, the gap between the expected and defacto usefulness of MIR solutions. This requires us to revisit the notion of relevance, but also to consider other criteria for assessing MIR solutions, like the informativeness of the retrieved results and how helpful they are for the users. The article also states that this focus shift cannot be realized incrementally, but by revisiting the foundations of MIR solutions, that is, by a
utility-by-design
approach. In this respect, a number of research challenges are proposed.
Multimedia systems research
Authors: Shenoy Prashant
Published: October 2013

This retrospective article examines the past two decades of multimedia systems research through the lens of three research topics that were in vogue in the early days of the field and offers perspectives on the evolution of these research topics. We discuss the eventual impact of each line of research and offer lessons for future research in the field.
Socially-aware multimedia authoring
Authors: Bulterman Dick C. A. , Cesar Pablo , Guimarães Rodrigo Laiola
Published: October 2013

Creating compelling multimedia productions is a nontrivial task. This is as true for creating professional content as it is for nonprofessional editors. During the past 20 years, authoring networked content has been a part of the research agenda of the multimedia community. Unfortunately, authoring has been seen as an initial enterprise that occurs before ‘real’ content processing takes place. This limits the options open to authors and to viewers of rich multimedia content for creating and receiving focused, highly personal media presentations. This article reflects on the history of multimedia authoring. We focus on the particular task of supporting
socially-aware multimedia
, in which the relationships within particular social groups among authors and viewers can be exploited to create highly personal media experiences. We provide an overview of the requirements and characteristics of socially-aware multimedia authoring within the context of exploiting community content. We continue with a short historical perspective on authoring support for these types of situations. We then present an overview of a current system for supporting socially-aware multimedia authoring within the community content. We conclude with a discussion of the issues that we feel can provide a fruitful basis for future multimedia authoring support. We argue that providing support for socially-aware multimedia authoring can have a profound impact on the nature and architecture of the entire multimedia information processing pipeline.
Instant convolution shadows for volumetric detail mapping
Authors: Patel Daniel , Šoltészová Veronika , Nordbotten Jan Martin , Bruckner Stefan
Published: October 2013

In this article, we present a method for rendering dynamic scenes featuring translucent procedural volumetric detail with all-frequency soft shadows being cast from objects residing inside the view frustum. Our approach is based on an approximation of physically correct shadows from distant Gaussian area light sources positioned behind the view plane, using iterative convolution. We present a theoretical and empirical analysis of this model and propose an efficient class of convolution kernels which provide high quality at interactive frame rates. Our GPU-based implementation supports arbitrary volumetric detail maps, requires no precomputation, and therefore allows for real-time modification of all rendering parameters.
Care and scale
Authors: Whitman Brian
Published: October 2013

The co-founder of The Echo Nest, a music intelligence company that now powers recommendation and discovery for most music services, discusses the notion of care and scale, cultural analysis of music, a brief history of music retrieval, and how and why The Echo Nest got started.
Advances in immersive communication
Authors: Chou Philip A.
Published: October 2013

The last great advances in immersive communication were the invention of the telephone over 137 years ago and the invention of the video telephone (né television) over 86 years ago. However, a perfect storm is brewing for the next advance in immersive communication, thanks to the convergence of massive amounts of computation, bandwidth, resolution, new sensors, and new displays. It could well be the Multimedia community that turns this brew into the next great advance in immersive communication, something akin to teleportation.
Exploiting unconscious user signals in multimodal human-computer interaction
Authors: Andre Elisabeth
Published: October 2013

This article presents the idea of empathic stimulation that relies on the power and potential of unconsciously conveyed attentive and emotional information to facilitate human-machine interaction. Starting from a historical review of related work presented at past ACM Multimedia conferences, we discuss challenges that arise when exploiting unconscious human signals for empathic stimulation, such as the real-time analysis of psychological user states and the smooth adaptation of the human-machine interface based on this analysis. A classical application field that might benefit from the idea of unconscious human-computer interaction is the exploration of massive datasets.
Social influence analysis and application on multimedia sharing websites
Authors: Sang Jitao , Xu Changsheng
Published: October 2013

Social media is becoming popular these days, where users necessarily interact with each other to form social networks. Influence network, as one special case of social network, has been recognized as significantly impacting social activities and user decisions. We emphasize in this article that the inter-user influence is essentially topic-sensitive, as for different tasks users tend to trust different influencers and be influenced most by them. While existing research focuses on global influence modeling and applies to text-based networks, this work investigates the problem of topic-sensitive influence modeling in the multimedia domain.

According to temporal data justification, we propose a multimodal probabilistic model, considering both users' textual annotation and uploaded visual images. This model is capable of simultaneously extracting user topic distributions and topic-sensitive influence strengths. By identifying the topic-sensitive influencer, we are able to conduct applications, like collective search and collaborative recommendation. A risk minimization-based general framework for personalized image search is further presented, where the image search task is transferred to measure the distance of image and personalized query language models. The framework considers the noisy tag issue and enables easy incorporation of social influence. We have conducted experiments on a large-scale Flickr dataset. Qualitative as well as quantitative evaluation results have validated the effectiveness of the topic-sensitive influencer mining model, and demonstrated the advantage of incorporating topic-sensitive influence in personalized image search and topic-based image recommendation.
Focus 3D
Authors: Maimone Andrew , Wetzstein Gordon , Hirsch Matthew , Lanman Douglas , Raskar Ramesh , Fuchs Henry
Published: October 2013

We present a glasses-free 3D display design with the potential to provide viewers with nearly correct accommodative depth cues, as well as motion parallax and binocular cues. Building on multilayer attenuator and directional backlight architectures, the proposed design achieves the high angular resolution needed for accommodation by placing spatial light modulators about a large lens: one conjugate to the viewer's eye, and one or more near the plane of the lens. Nonnegative tensor factorization is used to compress a high angular resolution light field into a set of masks that can be displayed on a pair of commodity LCD panels. By constraining the tensor factorization to preserve only those light rays seen by the viewer, we effectively steer narrow high-resolution viewing cones into the user's eyes, allowing binocular disparity, motion parallax, and the potential for nearly correct accommodation over a wide field of view. We verify the design experimentally by focusing a camera at different depths about a prototype display, establish formal upper bounds on the design's accommodation range and diffraction-limited performance, and discuss practical limitations that must be overcome to allow the device to be used with human observers.
Two decades of internet video streaming
Authors: Li Baochun , Wang Zhi , Liu Jiangchuan , Zhu Wenwu
Published: October 2013

For over two decades, video streaming over the Internet has received a substantial amount of attention from both academia and industry. Starting from the design of transport protocols for streaming video, research interests have later shifted to the peer-to-peer paradigm of designing streaming protocols at the application layer. More recent research has focused on building more practical and scalable systems, using Dynamic Adaptive Streaming over HTTP. In this article, we provide a retrospective view of the research results over the past two decades, with a focus on peer-to-peer streaming protocols and the effects of cloud computing and social media.
Understanding the role of phase function in translucent appearance
Authors: Gkioulekas Ioannis , Xiao Bei , Zhao Shuang , Adelson Edward H. , Zickler Todd , Bala Kavita
Published: October 2013

Multiple scattering contributes critically to the characteristic translucent appearance of food, liquids, skin, and crystals; but little is known about how it is perceived by human observers. This article explores the perception of translucency by studying the image effects of variations in one factor of multiple scattering: the phase function. We consider an expanded space of phase functions created by linear combinations of Henyey-Greenstein and von Mises-Fisher lobes, and we study this physical parameter space using computational data analysis and psychophysics.

Our study identifies a two-dimensional embedding of the physical scattering parameters in a perceptually meaningful appearance space. Through our analysis of this space, we find uniform parameterizations of its two axes by analytical expressions of moments of the phase function, and provide an intuitive characterization of the visual effects that can be achieved at different parts of it. We show that our expansion of the space of phase functions enlarges the range of achievable translucent appearance compared to traditional single-parameter phase function models. Our findings highlight the important role phase function can have in controlling translucent appearance, and provide tools for manipulating its effect in material design applications.
Gap processing for adaptive maximal poisson-disk sampling
Authors: Yan Dong-Ming , Wonka Peter
Published: October 2013

In this article, we study the generation of maximal Poisson-disk sets with varying radii. First, we present a geometric analysis of gaps in such disk sets. This analysis is the basis for maximal and adaptive sampling in Euclidean space and on manifolds. Second, we propose efficient algorithms and data structures to detect gaps and update gaps when disks are inserted, deleted, moved, or when their radii are changed. We build on the concepts of regular triangulations and the power diagram. Third, we show how our analysis contributes to the state-of-the-art in surface remeshing.
Data-driven control of flapping flight
Authors: Ju Eunjung , Won Jungdam , Lee Jehee , Choi Byungkuk , Noh Junyong , Choi Min Gyu
Published: October 2013

We present a physically based controller that simulates the flapping behavior of a bird in flight. We recorded the motion of a dove using marker-based optical motion capture and high-speed video cameras. The bird flight data thus acquired allow us to parameterize natural wingbeat cycles and provide the simulated bird with reference trajectories to track in physics simulation. Our controller simulates articulated rigid bodies of a bird's skeleton and deformable feathers to reproduce the aerodynamics of bird flight. Motion capture from live birds is not as easy as human motion capture because of the lack of cooperation from subjects. Therefore, the flight data we could acquire were limited. We developed a new method to learn wingbeat controllers even from sparse, biased observations of real bird flight. Our simulated bird imitates life-like flapping of a flying bird while actively maintaining its balance. The bird flight is interactively controllable and resilient to external disturbances.
Effect of Displaying Human Videos During an Evaluation Study of American Sign Language Animation
Authors: Kacorri Hernisa , Lu Pengfei , Huenerfauth Matt
Published: October 2013

Many researchers internationally are studying how to synthesize computer animations of sign language; such animations have accessibility benefits for people who are deaf and have lower literacy in written languages. The field has not yet formed a consensus as to how to best conduct evaluations of the quality of sign language animations, and this article explores an important methodological issue for researchers conducting experimental studies with participants who are deaf. Traditionally, when evaluating an animation, some lower and upper baselines are shown for comparison during the study. For the upper baseline, some researchers use carefully produced animations, and others use videos of human signers. Specifically, this article investigates, in studies where signers view animations of sign language and are asked subjective and comprehension questions, whether participants differ in their subjective and comprehension responses when actual videos of human signers are shown during the study. Through three sets of experiments, we characterize how the Likert-scale subjective judgments of participants about sign language animations are negatively affected when they are also shown videos of human signers for comparison -- especially when displayed side-by-side. We also identify a small positive effect on the comprehension of sign language animations when studies also contain videos of human signers. Our results enable direct comparison of previously published evaluations of sign language animations that used different types of upper baselines -- video or animation. Our results also provide methodological guidance for researchers who are designing evaluation studies of sign language animation or designing experimental stimuli or questions for participants who are deaf.
Path exploration based on symbolic output
Authors: Qi Dawei , Nguyen Hoang D. T. , Roychoudhury Abhik
Published: October 2013

Efficient program path exploration is important for many software engineering activities such as testing, debugging, and verification. However, enumerating all paths of a program is prohibitively expensive. In this article, we develop a partitioning of program paths based on the program output. Two program paths are placed in the same partition if they derive the output similarly, that is, the symbolic expression connecting the output with the inputs is the same in both paths. Our grouping of paths is gradually created by a smart path exploration. Our experiments show the benefits of the proposed path exploration in test-suite construction.

Our path partitioning produces a semantic signature of a program—describing all the different symbolic expressions that the output can assume along different program paths. To reason about changes between program versions, we can therefore analyze their semantic signatures. In particular, we demonstrate the applications of our path partitioning in testing and debugging of software regressions.
Software effort estimation as a multiobjective learning problem
Authors: Minku Leandro L. , Yao Xin
Published: October 2013

Ensembles of learning machines are promising for software effort estimation (SEE), but need to be tailored for this task to have their potential exploited. A key issue when creating ensembles is to produce diverse and accurate base models. Depending on how differently different performance measures behave for SEE, they could be used as a natural way of creating SEE ensembles. We propose to view SEE model creation as a multiobjective learning problem. A multiobjective evolutionary algorithm (MOEA) is used to better understand the tradeoff among different performance measures by creating SEE models through the simultaneous optimisation of these measures. We show that the performance measures behave very differently, presenting sometimes even opposite trends. They are then used as a source of diversity for creating SEE ensembles. A good tradeoff among different measures can be obtained by using an ensemble of MOEA solutions. This ensemble performs similarly or better than a model that does not consider these measures explicitly. Besides, MOEA is also flexible, allowing emphasis of a particular measure if desired. In conclusion, MOEA can be used to better understand the relationship among performance measures and has shown to be very effective in creating SEE models.
Portfolio
Authors: Mcmillan Collin , Poshyvanyk Denys , Grechanik Mark , Xie Qing , Fu Chen
Published: October 2013

Different studies show that programmers are more interested in finding definitions of functions and their uses than variables, statements, or ordinary code fragments. Therefore, developers require support in finding relevant functions and determining how these functions are used. Unfortunately, existing code search engines do not provide enough of this support to developers, thus reducing the effectiveness of code reuse. We provide this support to programmers in a code search system called
Portfolio
that retrieves and visualizes relevant functions and their usages. We have built Portfolio using a combination of models that address surfing behavior of programmers and sharing related concepts among functions. We conducted two experiments: first, an experiment with 49 C/C++ programmers to compare Portfolio to Google Code Search and Koders using a standard methodology for evaluating information-retrieval-based engines; and second, an experiment with 19 Java programmers to compare Portfolio to Koders. The results show with strong statistical significance that users find more relevant functions with higher precision with Portfolio than with Google Code Search and Koders. We also show that by using PageRank, Portfolio is able to rank returned relevant functions more efficiently.
Propagation-based social-aware multimedia content distribution
Authors: Wang Zhi , Zhu Wenwu , Chen Xiangwen , Sun Lifeng , Liu Jiangchuan , Chen Minghua , Cui Peng , Yang Shiqiang
Published: October 2013

Online social networks have reshaped how multimedia contents are generated, distributed, and consumed on today's Internet. Given the massive number of user-generated contents shared in online social networks, users are moving to directly access these contents in their preferred social network services. It is intriguing to study the service provision of social contents for global users with satisfactory quality of experience. In this article, we conduct large-scale measurement of a real-world online social network system to study the social content propagation. We have observed important propagation patterns, including social locality, geographical locality, and temporal locality. Motivated by the measurement insights, we propose a propagation-based social-aware delivery framework using a hybrid edge-cloud and peer-assisted architecture. We also design replication strategies for the architecture based on three propagation predictors designed by jointly considering user, content, and context information. In particular, we design a propagation region predictor and a global audience predictor to guide how the edge-cloud servers backup the contents, and a local audience predictor to guide how peers cache the contents for their friends. Our trace-driven experiments further demonstrate the effectiveness and superiority of our design.
Improving collaborative writing for the blind
Authors: Schoeberlein John G. , Wang Yuanqiong
Published: October 2013

Collaborative writing has become essential in organizations. However, current collaborative writing tools are not accessible and usable, which prevents persons who are blind from independently participating in group work when collaborative writing activities are involved. Based on several usability studies, we present a prototype of an interface that improves the collaborative writing experience for persons who are blind.
On the Sustainability of Renewable Energy Sources
Authors: Edenhofer Ottmar , Seyboth Kristin , Creutzig Felix , Schlömer Steffen
Published: October 2013

This article examines renewable energy (RE) technologies in a multiple-objective framework of sustainable development. We begin by locating RE in a portfolio of options available for climate change mitigation. Observing current trends in technologies, deployment levels, and costs, we discuss the future deployment levels envisioned in mitigation scenarios. We focus on biomass, given its importance in climate mitigation scenarios and because of the ongoing debates about its role in sustainability objectives. We also examine trends and successes in RE support policies. We conclude by linking the multiple objectives of sustainability to multiple policy instruments, emphasizing the need to closely consider the interaction between different policy instruments incentivizing sustainable development.
A Quantitative Study of Hydroxyl Radical Production on a Ti/SnO2-Sb2O5 Anode
Authors: Ni Qing , Kirk Donald W. , Thorpe Steven J.
Published: October 2013

A nitroso compound (R-NO) known as a “spin trap” was used to study the production of hydroxyl radicals (OH·) on a Ti/SnO2-Sb2O5 anode. A linear voltammetry study was conducted on this anode in the presence of this compound, using the rotating disk electrode technique. The results showed that the electrode started to produce (OH·) at 0.7V vs. Ag/AgCl reference electrode. The current was limited by the mass-transport of RNO in the electrolyte. When the voltage increased to 1.4V and higher, significant oxygen evolution took place. Further investigation was conducted by constant voltage electrolysis and spectroscopic measurement of the RNO concentration. The change in the RNO was interpreted as the evolution of (OH·), and the current efficiency was calculated based on the assumed stoichiometry. The results showed that the efficiency was optimal within the potential range 0.7-1.4V, and the highest efficiency could reach 30%. This was in agreement with the RDE experiment.
Platinized Counter Electrodes for Dye Sensitized Solar Cells through the Redox Replacement of a Low Power Electrodeposited Lead Sacrificial Template
Authors: Wragg David A , Yliniemi Kirsi , Watson Trystan M. , Worsley David A.
Published: October 2013

The mass production of photovoltaics, such as dye sensitized solar cells (DSCs), is of great interest to the renewable energy generation industry. DSCs are low cost, photoelectrochemical devices that use sensitized-TiO2, to generate electricity. Due to the need for an efficient platinum redox catalyst to facilitate electron return to the oxidized dye after electron injection this communication presents a fast, high performing, low cost platinisation process, leading to a viable in-line method of applying catalytic platinum. This method entails a low power deposition of Pb onto FTO-glass followed by the redox replacement of Pb by Pt ions in solution. When applied as a DSC counter electrode, the resulting cells gave efficiencies of 3% compared with standard cells using thermally platinized counter electrodes at 3.9%.
Low Cost TCO Less Counter Electrodes for Dye-Sensitized Solar Cell Application
Authors: Vyas Niladri , Wragg David A , Charbonneau Cecile , Carnie Matthew , Watson Trystan M.
Published: October 2013

This paper introduces a novel counter electrode material featuring a coating based on the incorporation of electrically conducting titanium nitride (TiN) particles into a polyimide (PI) matrix. The resulting hybrid system can be applied onto transparent substrates such as plain glass. The resulting composite coating is characterized with electrical conducting properties close to fluorine doped tin oxide (FTO) coated glass, a transparent conductive material widely used as a substrate in the fabrication of dye-sensitized solar cells (DSCs). This study investigates the use of TiN/PI coatings as an alternative to FTO-coated glass for the preparation of DSC counter electrodes. Platinization of the counter electrodes, a critical step aimed at catalyzing the reduction of the I3
- into I- within the electrolyte, is applied according to different techniques. DSC devices prepared on TiN/PI-coated glass counter electrodes show similar photovoltaic performance to DSCs prepared on commercial FTO-coated glass.
Reduction of CO2 to Methanol in Photoelectrochemical Cell: CM-n-TiO2 /Cu
Authors: Palanichamy Velammal , Hess David M. , Burke William M. , Frites Mourad , Gray McMahan L. , Khan Shahed U.M.
Published: October 2013

Reduction of CO2 to methanol was carried out in a two compartment photoelectrochemical cell using carbon modified titanium oxide (CM-n-TiO2) as a photoanode and Cu metal gauze as a dark cathode in an aqueous electrolyte of 5.0 M NaOH. Both compartments were connected by glass wool soaked in the same electrolyte. The CO2 reduction at the cathode in aqueous medium was coupled with the energetically challenging H2O oxidation reaction to O2 at CM-n-TiO2 photoanode. The reduction of CO2 to methanol was found to depend on the way CO2 solution was made. This is because most of the dissolved CO2 in aqueous medium should be intact in the molecular form trapped by water molecules via hydrogen bonding and adsorbed on energetically compatible Cu metal surface. No measurable amounts of reduction of CO2 to methanol were observed when it was mostly converted to CO3
2- and HCO3
- ions after dissolution. The highest amount of methanol, 2.5 × 10-8 moles cm-2 s-1 which is equivalent to 28.8 grams m-2 hr-1 was observed in first 5 min of reaction time. The amounts of methanol decreased after 5 min indicating back reaction at the photoanode. An average photoconversion efficiency of solar energy to methanol fuel energy was found to be ~ 11 % within 20 min. The reduction of CO2 to methanol was found to increase the yield by two fold in presence of initially added 0.5 mM methanol that acted as an autocatalyst.
Effect of Electrode Material on Resistive Switching Characteristics in TaON Nonvolatile Memory Devices
Authors: Chen Min-Chen , Chang Ting-Chang , Chiu Yi-Chieh , Chen Shih-Cheng , Huang Sheng-Yao , Syu Yong-En , Chang Kuan-Chang , Huang Hui-Chun , Tsai Tsung-Ming , Gan Der-Shin , Sze Simon M.
Published: October 2013

The devices composed of Pt/TaON/TiN reveal bipolar switching behavior that shows excellent resistance ratio of 102 with operations over 100 DC cycles. The formation/disruption of conducting filaments by oxygen anions migration near/at the TiN electrode was applied to explain the switching behavior. In comparison with Pt/TaON/TiN device, the Cu/TaON/TiN device exhibits reversed bipolar resistive switching characteristic. The switching mechanism of Cu/TaON/TiN device is regarded as the Cu redox reaction and migration in the TaON film. Furthermore, the setting voltage of the Cu/TaON/TiN device is lower than that of the Pt/TaON/TiN device due to the confined conduction path by Cu filaments.
Direct Laser Patterning of Self Assembled Monolayers (SAMs) on Cobalt Chromium (Co-Cr) Alloy
Authors: Bhure Rahul , Mahapatro Anil , Bonner Carl
Published: October 2013

Many implantable biomedical devices suffer from post-operative infections. To effectively treat post-operative infections, prevention of biofilm and tissue integrations needs to be addressed simultaneously. In this manuscript we report the direct laser patterning of SAMs on Co-Cr alloy that could serve as a platform for multi therapeutic delivery. A sapphire femtosecond pulsed laser was used to etch the SAMs on the Co-Cr alloy. Atomic force microscope (AFM) showed the surface topography before and after the laser etches as well as determined the diameter of laser etches. The experimental value of the diameter of the laser etch closely matched the theoretical predicted values.