Complex Interactive Environments Research Articles

Negative Photoconductivity Transistors for Visuomorphic Computing.

Visuomorphic computing aims to simulate and potentially surpass the human retina by mimicking biological visual perception with an artificial retina. Despite significant progress, challenges persist in perceiving complex interactive environments. Negative photoconductivity transistors (NPTs) mimic synaptic behavior by achieving adjustable positive photoconductivity (PPC) and negative photoconductivity (NPC), simulating "excitation" and "inhibition" akin to sensory cell signals. In complex interactive environments, NPTs are desired for visuomorphic computing that can achieve a better sense of information, lower power consumption, and reduce hardware complexity. In this review, it is started by introducing the development process of NPTs, while placing a strong emphasis on the device structures, working mechanisms, and key performance parameters. The common material systems employed in NPTs based on their functions are then summarized. Moreover, it is proceeded to summarize the noteworthy applications of NPTs in optoelectronic devices, including advanced multibit nonvolatile memory, optoelectronic logic gates, optical encryption, and visual perception. Finally, the challenges and prospects that lie ahead in the ongoing development of NPTs are addressed, offering valuable insights into their applications in optoelectronics and a comprehensive understanding of their significance.

Analysis of driving behavior in weak lane disciplined traffic at the merging and diverging sections using unmanned aerial vehicle data

The complexity of vehicular interactions at the merging and diverging sections is more severe due to the multiple decisions the driver has to make in a short time. The present study investigates and quantifies the driving behavior at the toll plaza’s merging and diverging sections. High-quality trajectory data for more than 7500 vehicle trajectories was derived from traffic video footage recorded by two Unmanned Aerial Vehicles (UAVs) operating concurrently upstream and downstream of the toll plaza. The data was extracted at 5 Hz, generating more than 5 million data points for the study. This approach facilitated a comprehensive and simultaneous capture of traffic dynamics. Various macroscopic and microscopic traffic parameters, like lateral and longitudinal speeds, following time, perception time, longitudinal standstill distance, and lateral clearance in the upstream and downstream sections, have been determined under weak lane disciplined traffic conditions. The mean speed in the merging section is 33.13 % lower than in the diverging section. Additionally, the average lateral speed in the merging section is 1.65 km/h, in contrast to 2.08 km/h in the diverging section, reflecting a 26 % increase. The lane changing and merging is prominent only up to 120 m to 140 m from the toll plaza in the merging section, and for diverging, 100 m to 200 m towards the toll plaza. The average following time in the diverging section is 5.7 s; for the merging section, it is 6.94 s, which is 13.86 % higher. The average perception time for the diverging section is 15.32 s; for the merging section, it is 13.13 s, which is 14.29 % lower. It has been observed that lateral clearance has a concave relationship with the speed in the merging section, whereas a convex relationship is in the diverging section due to the geometrical changes. The results presented in the study are expected to imitate heterogeneous traffic conditions observed in the field more realistically and will accelerate the understanding of behavioral aspects in complex interactive environments like that at merging and diverging sections of toll plazas.

Virtually the ultimate research lab.

Virtual reality (VR) can serve as a viable platform for psychological research. The real world with many uncontrolled variables can be masked to immerse participants in complex interactive environments that are under full experimental control. However, as any other laboratory setting, these simulations are not perceived equally to reality and they also afford different behaviour. We need a better understanding of these differences, which are often related to parameters of the technical setup, to support valid interpretations of experimental results.

What/Where to Look Next? Modeling Top-Down Visual Attention in Complex Interactive Environments

Several visual attention models have been proposed for describing eye movements over simple stimuli and tasks such as free viewing or visual search. Yet, to date, there exists no computational framework that can reliably mimic human gaze behavior in more complex environments and tasks such as urban driving. In addition, benchmark datasets, scoring techniques, and top-down model architectures are not yet well understood. In this paper, we describe new task-dependent approaches for modeling top-down overt visual attention based on graphical models for probabilistic inference and reasoning. We describe a dynamic Bayesian network that infers probability distributions over attended objects and spatial locations directly from observed data. Probabilistic inference in our model is performed over object-related functions that are fed from manual annotations of objects in video scenes or by state-of-the-art object detection/recognition algorithms. Evaluating over approximately 3 h (approximately 315 000 eye fixations and 12 000 saccades) of observers playing three video games (time-scheduling, driving, and flight combat), we show that our approach is significantly more predictive of eye fixations compared to: 1) simpler classifier-based models also developed here that map a signature of a scene (multimodal information from gist, bottom-up saliency, physical actions, and events) to eye positions; 2) 14 state-of-the-art bottom-up saliency models; and 3) brute-force algorithms such as mean eye position. Our results show that the proposed model is more effective in employing and reasoning over spatio-temporal visual data compared with the state-of-the-art.

Cellular Immune Response and Cytokine Profile Among Hepatitis C Positive Living Donor Renal Transplant Recipients

Hepatitis C virus (HCV) infection is prevalent among renal transplant recipients. Twenty-five recipients of living donor renal transplantation with HCV (group I) and without HCV (group II) were serially monitored at three time points, that is, pretransplant, day 10, and 6 months posttransplant. Phenotypic characterization of T-cell subsets and natural killer cells was performed by flow cytometric immunophenotyping. Cytometric bead array immunoassay was used to simultaneously measure six cytokines (interleukin [IL]-2, IL-4, IL-5, IL-10, tumor necrosis factor-α, and interferon-γ) from phytohemagglutin-stimulated culture supernatants, and transforming growth factor (TGF)-β1 levels were determined by ELISA. Real-time polymerase chain reaction method was used to determine the serum viral load among group I patients at three time points. Group I patients on day 10 posttransplant showed a significant increase in T cells subsets with reduced interferon-γ and increased TGF-β1 levels. A significantly increased CD8 T cells and TGF-β levels were seen at 6-month posttransplant among group I patients. Multivariate linear regression analysis showed TGF-β and tumor necrosis factor-α as the most significant predictors affecting early (day 10) and late (6 months) posttransplant viral load, respectively. After an initial increase in the viral load immediately posttransplantation, there is a reduction in viral load. A concomitant timed dissection of the immune response shows a complex interactive environment in which, despite immunosuppression, not only the antiviral immune response persists but the virus is also able to modulate the host immune response for its survival. Per se, HCV does not adversely affect the allograft or patient outcome in this case-control study.

Designing for All in Ambient Intelligence Environments: The Interplay of User, Context, and Technology

This article outlines issues that emerge from the evolution of the Information Society towards Ambient Intelligence (AmI) environments, focusing on the diversity of human needs, the dynamic evolution of context, and the multifaceted characteristics of interactive technologies. Such an evolution brings forward many implications and challenges in the context of Universal Access, that is, accessibility and usability of Information Society Technologies by all users, independently of individual abilities and characteristics. Identified research challenges include the investigation of human requirements in the context of AmI, suitable approaches to nonfunctional characteristics (such as accessibility, privacy, security, and safety), suitable models of the context of use, appropriate interaction devices and techniques for diverse users and contexts of use, interaction design for continuous and implicit interaction, elaboration of design methods suitable for very complex interactive environments, and mechanisms for interaction adaptation. This article argues that such challenges in the context of AmI environments can be addressed by systematically investigating the interplay between the user, the context, and the technologies. Such a research direction requires systematic approaches to diverse human needs, dynamic context characteristics, and technology possibilities, all of which need to be elaborated and validated in practice.

Louise Lovely, Bluebird Photoplays, and the Star System

[End Page 64] Focusing on Australian silent actress Louise Lovely, this paper outlines some complex and ambiguous attitudes toward the star system in early Hollywood. This exploration takes as its starting point the poster in Figure 1 and examines the importance of Lovely's name, which was linked to her contract with Universal and her prominent roles in "expensive" Bluebird Photoplay productions. Universal surrounded Lovely with star hype at exactly the same time that its studio heads were publicly critical of the star system and were devising strategies to control stars. Who was Louise Lovely? Although in one Australian film history she was labeled "Australia's foremost international screen star,"1 she is little remembered today. Born in 1895, she appeared in early Australian cinema productions as Louise Carbasse, then was [End Page 65] featured in fifty-plus Hollywood films between 1915 and 1922,2 of which only a handful still exist.3 The low survival numbers aren't unusual for films from this era, and the two studios for which she did much of her Hollywood work were Universal and Fox, whose silent productions have particularly high rates of loss. Click for larger view Figure 1 Color genre portrait, Louise Lovely/Bluebird Photoplays, n.d. From the collections of ScreenSound Australia, the National Film and Sound Archive. The disappearance of Lovely's films is unfortunate, if for no other reason than today preventing an assessment of her screen presence. However, research into how her star persona was built can still be conducted.4 The nature of this investigation involves [End Page 66] extensive archival searching in a wide variety of materials ranging from legal documents, advertisements, and costumes to promotional ephemera. Richard Dyer, one of the first and most influential theorists of star studies, has pointed out that, although "[a] film star's films are likely to have a privileged place in his or her image," it is in fact the ephemera that constructs stardom: The star phenomenon consists of everything that is publicly available about stars. A star's image is not just his or her films, but the promotion of those films and of the star through pin-ups, public appearances, studio hand-outs and so on, as well as interviews, biographies and coverage in the press of the star's doings and "private" life.5 Ironically, this poster, as well as other "ephemeral" materials, have outlasted Lovely herself as well as her films. Methodology Because star images are comprised of many different texts, they encompass colliding discourses. The methodology for the overall project, then, had to preserve contradictions, resistances, and instabilities and to avoid attempts to reconcile them. It also had to be able to meet the need to carefully reconstruct industry strategies—which demanded a detailed historical perspective—as well as understand how audiences may have experienced Lovely's star persona—which oriented the methodology toward reception studies. For reasons of length, this paper omits the reception-studies exploration of the connotations of "Lovely,"6 concentrating on a historical reconstruction of industry star strategies associated with star names. To meet the differing needs of these connected investigations, the methodology for the overall project was modeled on the "total history" described by Barbara Klinger's article, "Film History Terminable and Interminable." She warns of possible inadequacies in studies that focus on one type of text only, such as reviews or the films themselves, and argues for looking at the "complex interactive environments or levels of society involved in the production of a particular event."7 Klinger's approach, reflecting the influence of reception studies, is similar to that of Janet Staiger, in Interpreting Films: Studies in the Historical Reception of American Cinema, and Sarah Street, who points out that, in looking at film, "material often regarded as extraneous can contribute to our [End Page 67] understanding of film in its cultural and historical context."8 While there is nothing new in this approach, it was particularly useful to study...

Evaluating Comprehension-Based User Models: Predicting Individual User Planning and Action

Described is a program of research that uses rigorous methods to evaluate models of user cognition and action based on the construction-integration architecture of comprehension (Doane and Sohn, 2000; Kintsch, 1988; 1998). The models interrelate user environmental information, background knowledge, and current goals, and then spread activation throughout the interrelated information to simulate UNIX user command productions, aviation pilot eye fixations and control movements during flight, and army personnel intelligence planning. Models of individuals in the complex interactive environments are tested for descriptive as well as predictive validity. Comparisons of model and human empirical data have resulted in a high degree of agreement, validating the ability of the comprehension-based architecture to support models that can predict user performance. Evaluation methods are detailed and the importance of evaluative rigor is discussed.