Papers by Jafet Rodriguez
arXiv (Cornell University), Sep 8, 2021
Spatial drawing using ruled-surface brush strokes is a popular mode of content creation in immers... more Spatial drawing using ruled-surface brush strokes is a popular mode of content creation in immersive VR, yet little is known about the usability of existing spatial drawing interfaces or potential improvements. We address these questions in a threephase study. (1) Our exploratory need-finding study (N=8) indicates that popular spatial brushes require users to perform large wrist motions, causing physical strain. We speculate that this is partly due to constraining users to align their 3D controllers with their intended stroke normal orientation. (2) We designed and implemented a new brush interface that significantly reduces the physical effort and wrist motion involved in VR drawing, with the additional benefit of increasing drawing accuracy. We achieve this by relaxing the normal alignment constraints, allowing users to control stroke rulings, and estimating normals from them instead. (3) Our comparative evaluation of StripBrush (N=17) against the traditional brush shows that StripBrush requires significantly less physical effort and allows users to more accurately depict their intended shapes while offering competitive ease-of-use and speed.
Applied Sciences
User experience (UX) is key in the immediate and future relationship between the client and busin... more User experience (UX) is key in the immediate and future relationship between the client and business. Achieving a satisfying UX can only be achieved by understanding the wishes and user needs. The following study is carried out as an improvement tool for a Mexican coffee company. The objective is to achieve greater efficiency, attraction, and engagement on the part of the user. The main question is whether the new dynamic website design can directly increase the valence of user emotions compared to the static website design. To answer this question, 39 participants were exposed to the two different web page designs and elicited the following emotions using eye tracking and facial expression analysis (FEA) techniques: joy, anger, surprise, fear, contempt, disgust, sadness, neutral, positive, and negative. Through a Wilcoxon signed-rank test, the results showed a significant increase for the new dynamic design in the following emotions; joy, anger, surprise, disgust, fear and neutral....
International Journal of Environmental Research and Public Health
Over seven million people suffer from an impairment in Mexico; 64.1% are gait-related, and 36.2% ... more Over seven million people suffer from an impairment in Mexico; 64.1% are gait-related, and 36.2% are children aged 0 to 14 years. Furthermore, many suffer from neurological disorders, which limits their verbal skills to provide accurate feedback. Robot-assisted gait therapy has shown significant benefits, but the users must make an active effort to accomplish muscular memory, which usually is only around 30% of the time. Moreover, during therapy, the patients’ affective state is mostly unsatisfied, wide-awake, and powerless. This paper proposes a method for increasing the efficiency by combining affective data from an Emotiv Insight, an Oculus Go headset displaying an immersive interaction, and a feedback system. Our preliminary study had eight patients during therapy and eight students analyzing the footage using the self-assessment Manikin. It showed that it is possible to use an EEG headset and identify the affective state with a weighted average precision of 97.5%, recall of 87....
Visionless Interactions: Plataforma de aplicaciones para invidentes
Instituto Tecnológico y de Estudios Superiores de Monterrey, Mar 15, 2019
AdaptiBrush
ACM Transactions on Graphics, 2021
Virtual reality drawing applications let users draw 3D shapes using brushes that form ribbon shap... more Virtual reality drawing applications let users draw 3D shapes using brushes that form ribbon shaped, or ruled-surface, strokes. Each ribbon is uniquely defined by its user-specified ruling length, path, and the ruling directions at each point along this path. Existing brushes use the trajectory of a handheld controller in 3D space as the ribbon path, and compute the ruling directions using a fixed mapping from a specific controller coordinate-frame axis. This fixed mapping forces users to rotate the controller and thus their wrists to change ribbon normal or ruling directions, and requires substantial physical effort to draw even medium complexity ribbons. Since human ability to rotate their wrists continuously is heavily restricted, the space of ribbon geometries users can comfortably draw using these brushes is limited. These brushes can be unpredictable, producing ribbons with unexpectedly varying width or flipped and wobbly normals in response to seemingly natural hand gestures....
ACM Transactions on Graphics, 2019
Popular Virtual Reality (VR) tools allow users to draw varying-width, ribbonlike 3D brush strokes... more Popular Virtual Reality (VR) tools allow users to draw varying-width, ribbonlike 3D brush strokes by moving a hand-held controller in 3D space. Artists frequently use dense collections of such strokes to draw virtual 3D shapes. We propose SurfaceBrush , a surfacing method that converts such VR drawings into user-intended manifold free-form 3D surfaces, providing a novel approach for modeling 3D shapes. The inputs to our method consist of dense collections of artist-drawn stroke ribbons described by the positions and normals of their central polylines, and ribbon widths. These inputs are highly distinct from those handled by existing surfacing frameworks and exhibit different sparsity and error patterns, necessitating a novel surfacing approach. We surface the input stroke drawings by identifying and leveraging local coherence between nearby artist strokes. In particular, we observe that strokes intended to be adjacent on the artist imagined surface often have similar tangent directi...
IT Professional, 2019
Cryptocurrencies promise to revolutionize the financial market due to two main features: security... more Cryptocurrencies promise to revolutionize the financial market due to two main features: security and decentralization. In this article, the authors analyze whether cryptocurrencies are fully decentralized-in other words, whether the transaction processing is distributed among different entities. In addition, they present the consequences that a possible centralization entails.
Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2016
Wireless Sensor Networks (WSNs) have large applications in environments where access to human can... more Wireless Sensor Networks (WSNs) have large applications in environments where access to human cannot be constant or where reliable and timely information is required to support decisions. WSNs must show high reliability, robustness, availability of information, monitoring capabilities, self-organization, among other aspects. Also, engineering requirements, such as low-cost implementation, operation, and maintenance are necessary. In this context, a simulator is a powerful tool for analyzing and improving network technologies used as a first step to investigate protocol design and performance test on large-scale systems without the need of real implementation. In this paper, we present a Configurable Multi-Layer WSN (CML-WSN) simulator. The CML-WSN simulator incorporates a configurable energy model to support any sensor specification as a one of its main features. The CML-WSN simulator is useful because it allows exploring prototypes with much less cost and time compared to the requirements needed in real networks implementations.
Predictive Tool for Planning the Scaling and Interference of Wireless Sensor Networks
2018 IEEE 10th Latin-American Conference on Communications (LATINCOM), 2018
The Internet of Things has introduced a new era of devices capable of sensing different parameter... more The Internet of Things has introduced a new era of devices capable of sensing different parameters from an environment. Unfortunately, these sensors use multiple standards and are not always designed to work together in a Wireless Body Area Network (WBAN). We studied various applications of the combination of these devices to try and establish an ideal environment which reduces interference and improves data delivery reliability. In this paper we propose a graphical network simulator capable of scaling multiple scenarios, which was tested with a real environment, simulating a WBAN, using five nodes in a ZigBee network where one of them acted as the coordinator and with an approximate overall error rate of ±13.5% in performance metrics such as Packet Delivery Ratio, Link Quality Indicator and Received Signal Strength Indication. Finally, we were able to extrapolate the number of nodes to predict the scalability and the interference influence on a network.
Uploads
Papers by Jafet Rodriguez