96 research outputs found
Imitating Human Responses via a Dual-Process Model Approach
Human-autonomous system teaming is becoming more prevalent in the Air Force and in society. Often, the concept of a shared mental model is discussed as a means to enhance collaborative work arrangements between a human and an autonomous system. The idea being that when the models are aligned, the team is more productive due to an increase in trust, predictability, and apparent understanding. This research presents the Dual-Process Model using multivariate normal probability density functions (DPM-MN), which is a cognitive architecture algorithm based on the psychological dual-process theory. The dual-process theory proposes a bipartite decision-making process in people. It labels the intuitive mode as “System 1” and the reflective mode as “System 2”. The current research suggests by leveraging an agent which forms decisions based on a dual-process model, an agent in a human-machine team can maintain a better shared mental model with the user. Evaluation of DPM-MN in a game called Space Navigator shows that DPM-MN presents a successful dual-process theory motivated model
Spectrum Sharing, Latency, and Security in 5G Networks with Application to IoT and Smart Grid
The surge of mobile devices, such as smartphones, and tables, demands additional capacity. On the other hand, Internet-of-Things (IoT) and smart grid, which connects numerous sensors, devices, and machines require ubiquitous connectivity and data security. Additionally, some use cases, such as automated manufacturing process, automated transportation, and smart grid, require latency as low as 1 ms, and reliability as high as 99.99\%. To enhance throughput and support massive connectivity, sharing of the unlicensed spectrum (3.5 GHz, 5GHz, and mmWave) is a potential solution. On the other hand, to address the latency, drastic changes in the network architecture is required. The fifth generation (5G) cellular networks will embrace the spectrum sharing and network architecture modifications to address the throughput enhancement, massive connectivity, and low latency.
To utilize the unlicensed spectrum, we propose a fixed duty cycle based coexistence of LTE and WiFi, in which the duty cycle of LTE transmission can be adjusted based on the amount of data. In the second approach, a multi-arm bandit learning based coexistence of LTE and WiFi has been developed. The duty cycle of transmission and downlink power are adapted through the exploration and exploitation. This approach improves the aggregated capacity by 33\%, along with cell edge and energy efficiency enhancement. We also investigate the performance of LTE and ZigBee coexistence using smart grid as a scenario.
In case of low latency, we summarize the existing works into three domains in the context of 5G networks: core, radio and caching networks. Along with this, fundamental constraints for achieving low latency are identified followed by a general overview of exemplary 5G networks. Besides that, a loop-free, low latency and local-decision based routing protocol is derived in the context of smart grid. This approach ensures low latency and reliable data communication for stationary devices.
To address data security in wireless communication, we introduce a geo-location based data encryption, along with node authentication by k-nearest neighbor algorithm. In the second approach, node authentication by the support vector machine, along with public-private key management, is proposed. Both approaches ensure data security without increasing the packet overhead compared to the existing approaches
Congestion control for real-time interactive multimedia streams
The Internet is getting richer, and so the services. The richer the services, the more the users demand.
The more they demand, the more we guarantee(1).
This thesis investigates the congestion control mechanisms for interactive multimedia streaming
applications. We start by raising a question as to why the congestion control schemes are not widely
deployed in real-world applications, and study what options are available at present. We then discuss and
show some of the good reasonings that might have made the control mechanism, specifically speaking
the rate-based congestion control mechanism, not so attractive.
In an effort to address the problems, we identify the existing problems from which the rate-based
congestion control protocol cannot easily escape. We therefore propose a simple but novel windowbased
congestion control protocol that can retain smooth throughput property while being fair when
competing with TCP, yet still being responsive to the network changes.
Through the extensive ns-2 simulations and the real-world experiments, we evaluate TFWC, our
proposed mechanisms, and TFRC, the proposed IETF standard, in terms of network-oriented metrics
(fairness, smoothness, stability, and responsive), and end-user oriented metrics (PSNR and MOS) to
throughly study the protocol’s behaviors. We then discuss and conclude the options of the evaluated
protocols for the real application. (1)We as congestion control mechanisms in the Internet
Efficient, Reliable and Secure Distributed Protocols for MANETs
This thesis is divided into two parts. The first part explores the difficulties of
bootstrapping and maintaining a security infrastructure for military Mobile Ad Hoc
NETworks (MANETs). The assumed absence of dedicated infrastructural elements
necessitates, that security services in ad hoc networks may be built from the ground
up. We develop a cluster algorithm, incorporating a trust metric in the cluster head
selection process to securely determine constituting nodes in a distributed Trust
Authority (TA) for MANETs. Following this, we develop non-interactive key distribution
protocols for the distribution of symmetric keys in MANETs. We explore
the computational requirements of our protocols and simulate the key distribution
process.
The second part of this thesis builds upon the security infrastructure of the first
part and examines two distributed protocols for MANETs. Firstly, we present a
novel algorithm for enhancing the efficiency and robustness of distributed protocols
for contacting TA nodes in MANETs. Our algorithm determines a quorum of
trust authority nodes required for a distributed protocol run based upon a set of
quality metrics, and establishes an efficient routing strategy to contact these nodes.
Secondly, we present a probabilistic path authentication scheme based on message
authentication codes (MACs). Our scheme minimises both communication and computation
overhead in authenticating the path over which a stream of packets travels
and facilitates the detection of adversarial nodes on the path
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Photo manipulation: the influence of implicit visual arguments on dual processing
textIndividuals view an overwhelming number of mediated messages every day, even if most of these messages are merely glanced at or given minimal amounts of attention. It is not possible or advantageous for individuals to critically evaluate all messages they encounter. In that first glance or initial impression, however, our brains process the visual arguments designed by photo manipulation presented in messages. This happens instinctually, almost instantaneously, and most often underneath our radar of consciousness. Following, individuals decide to attend to the information (or not) though conscious processing. Regardless of decisions for elaborative processing, however, the initial visual processing of photo manipulated arguments influences how individuals think, feel, and behave – whether they are aware of it or not. This dissertation contributes to our understanding of the role of implied visual arguments for persuasive message processing in three ways. First, Experiment 1 identified and provided empirical evidence for effects of photo manipulation as a visual persuasion technique. This experiment was a necessary first step in exploring the cause-and-effect relationship of photo manipulation and attitudes to better understand influences on message perception. Second, Experiment 2 tested currently used dual processing approaches for persuasive messages to overcome the gaps that currently exist. Theoretical frameworks widely used in advertising and communication research – ELM and HSM – largely overlook the influence of visual communication and visual processing. These models do not account for the current understand of the brain mechanisms and processes for message processing. Findings from Experiment 2 provide evidence for the need to refine these models to account for influential visual processing variables that are largely absent from the literature. Third, findings from both experiments contributed to the conceptual refinement of visual literacy with evidenced-based support for the boundaries of when this concept is (or is not) influential for assigning meaning to visual messages.Advertisin
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Digital geographies of transnational spaces: a mixed-method study of Mexico-US migration
textThe central objective of this thesis is to explore how sophisticated information and communication technologies (ICTs) impact Mexico-US migration. In particular, it attends to those ICTs that enable Mexican immigrants in the United States to stay “in touch” with their loved ones in Mexico. Rather than pursue the impacts of these technologies through a singular methodology or theoretical framework, this study employs an array of approaches in order to examine the geography transnational communication across multiple scales. At the level of the individual, I examine how Mexican immigrants living in Austin, TX, incorporate communication technologies into their daily lives. Informed by a series of semi-structured and in-depth interviews, I argue that cellular phone calls, text messaging, and social media platforms enable a passive, routinized transnationalism that allows migrants to maintain a degree of presence both “here” and “there.” I subsequently scale up my analysis in order to trace the emergence of digital social media—Facebook, in particular—as a communication tool for dispersed Mexican immigrant communities, and I interrogate the ways in which digital social media engender transnational social networks. Using place as a guiding conceptual theme, I demonstrate how senses of and attachments to place form the basis of communal social interactions online, and I identify the many different places, both in the US and Mexico, that are involved in particular transnational social networks and migration flows. This study concludes by drawing on recent critical GIS scholarship and volunteered geographic information (VGI) in order to visualize the digital, place-to-place connections between Mexican migrants living in United States and their friends and family members living in Mexico and elsewhere.Geography and the Environmen
De-Sign Environment Landscape City Atti
La VI Conferenza Internazionale sul Disegno, De_Sign Environment Landscape City_Genova 2020 tratta di: Rilievo e Rappresentazione dell’Architettura e dell’Ambiente; Il Disegno per il paesaggio; Disegni per il Progetto: tracce - visioni e pre-visioni; I margini i segni della memoria e la città in progress; Cultura visiva e comunicazione dall’idea al progetto; Le emergenze architettoniche; Il colore e l’ambiente; Percezione e identità territoriale; Patrimonio iconografico culturale paesaggistico: arte, letteratura e ricadute progettuali; Segni e Disegni per il Design e Rappresentazione avanzata. Federico Babina, architetto e graphic designer presenta ARCHIVISION, e Eduardo Carazo Lefort, Docente dell’Università di Valladolid e Targa d’Oro dell’Unione Italiana Disegno la Lectio Magistralis.
The VI International Conference on Drawing, De_Sign Environment Landscape City_Genoa 2020, deals with: Survey and Representation of Architecture and the Environment; Drawing for the landscape; De-signs for the Project: traces-visions and previews; Margins, signs of memory and the city in progress; Visual culture and communication from idea to project; Architectural emergencies; The color and the environment; Perception and territorial identity; Landscape cultural iconographic heritage: art, literature and design implications; Signs and Drawings for Design and Advanced Representation. Federico Babina, architect and graphic designer presents ARCHIVISION, and Professor Eduardo Carazo Lefort-University of Valladolid and Gold Plate of the Italian Design Union presents his Lectio Magistralis
Layer-based coding, smoothing, and scheduling of low-bit-rate video for teleconferencing over tactical ATM networks
This work investigates issues related to distribution of low bit rate video within the context of a teleconferencing application deployed over a tactical ATM network. The main objective is to develop mechanisms that support transmission of low bit rate video streams as a series of scalable layers that progressively improve quality. The hierarchical nature of the layered video stream is actively exploited along the transmission path from the sender to the recipients to facilitate transmission. A new layered coder design tailored to video teleconferencing in the tactical environment is proposed. Macroblocks selected due to scene motion are layered via subband decomposition using the fast Haar transform. A generalized layering scheme groups the subbands to form an arbitrary number of layers. As a layering scheme suitable for low motion video is unsuitable for static slides, the coder adapts the layering scheme to the video content. A suboptimal rate control mechanism that reduces the kappa dimensional rate distortion problem resulting from the use of multiple quantizers tailored to each layer to a 1 dimensional problem by creating a single rate distortion curve for the coder in terms of a suboptimal set of kappa dimensional quantizer vectors is investigated. Rate control is thus simplified into a table lookup of a codebook containing the suboptimal quantizer vectors. The rate controller is ideal for real time video and limits fluctuations in the bit stream with no corresponding visible fluctuations in perceptual quality. A traffic smoother prior to network entry is developed to increase queuing and scheduler efficiency. Three levels of smoothing are studied: frame, layer, and cell interarrival. Frame level smoothing occurs via rate control at the application. Interleaving and cell interarrival smoothing are accomplished using a leaky bucket mechanism inserted prior to the adaptation layer or within the adaptation layerhttp://www.archive.org/details/layerbasedcoding00parkLieutenant Commander, United States NavyApproved for public release; distribution is unlimited
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