Artificial potential functions for highway driving with collision avoidance

We present a set of potential function components to assist an automated or semi-automated vehicle in navigating a multi-lane, populated highway. The resulting potential field is constructed as a superposition of disparate functions for lane- keeping, road-staying, speed preference, and vehicle avoidance and passing. The construction of the vehicle avoidance potential is of primary importance, incorporating the structure and protocol of laned highway driving. Particularly, the shape and dimensions of the potential field behind each obstacle vehicle can appropriately encourage control vehicle slowing and/or passing, depending on the cars' velocities and surrounding traffic. Hard barriers on roadway edges and soft boundaries between navigable lanes keep the vehicle on the highway, with a preference to travel in a lane center

Indexing multi-dimensional uncertain data with arbitrary probability density functions

Research Session 26: Spatial and Temporal DatabasesIn an "uncertain database", an object o is associated with a multi-dimensional probability density function (pdf), which describes the likelihood that o appears at each position in the data space. A fundamental operation is the "probabilistic range search" which, given a value p q and a rectangular area r q, retrieves the objects that appear in r q with probabilities at least p q. In this paper, we propose the U-tree, an access method designed to optimize both the I/O and CPU time of range retrieval on multi-dimensional imprecise data. The new structure is fully dynamic (i.e., objects can be incrementally inserted/deleted in any order), and does not place any constraints on the data pdfs. We verify the query and update efficiency of U-trees with extensive experiments.postprintThe 31st International Conference on Very Large Data Bases (VLDB 2005), Trondheim, Norway, 30 August-2 September 2005. In Proceedings of 31st VLDB, 2005, v. 3, p. 922-93

The Effects of Interaction with Conserving Adults and Peers on the Acquisition of Conservation by Nonconservers

Nonconserving children were placed in a situation where they had to interact with either two conserving adults or two conserving children. Each triad (one nonconserver and two conservers) was asked to give judgments and explanations for conservation problems. The type of conserving explanations (invariant quantity, reversibility, and compensation) given by the conservers in the interaction were varied. Approximately one week after the interaction the nonconserving subjects were posttested and the results indicated that nonconservers increased in conservation score after interacting with conservers. Hearing different explanations did not differentially affect the scores of nonconservers. The results did indicate that invariant quantity explanations were used more often than either reversibility or compensation explanations by the subjects after the interaction. There were no differential effects when interacting with either adult or peer conservers. These results were discussed in terms of Piagetian Theory. The ramifications of these findings on our educational systems were discussed as were suggestions for future research

Magnetic Alignment of Microelements Containing Cultured Neuronal Networks for High-Throughput Screening

High-throughput screening (HTS) on neurons presents unique difficulties because they are postmitotic, limited in supply, and challenging to harvest from animals or generate from stem cells. These limitations have hindered neurological drug discovery, leaving an unmet need to develop cost-effective technology for HTS using neurons. Traditional screening methods use up to 20,000 neurons per well in 384-well plates. To increase throughput, we use “microraft” arrays, consisting of 1600 square, releasable, paramagnetic, polystyrene microelements (microrafts), each providing a culture surface for 500–700 neurons. These microrafts can be detached from the array and transferred to 384-well plates for HTS; however, they must be centered within wells for automated imaging. Here, we developed a magnet array plate, compatible with HTS fluid-handling systems, to center microrafts within wells. We used finite element analysis to select an effective size of the magnets and confirmed that adjacent magnetic fields do not interfere. We then experimentally tested the plate’s centering ability and found a centering efficiency of 100%, compared with 4.35% using a flat magnet. We concluded that microrafts could be centered after settling randomly within the well, overcoming friction, and confirmed these results by centering microrafts containing hippocampal neurons cultured for 8 days

Multimodal assessment of emotional responses by physiological monitoring: novel auditory and visual elicitation strategies in traditional and virtual reality environments

This doctoral thesis explores novel strategies to quantify emotions and listening effort through monitoring of physiological signals. Emotions are a complex aspect of the human experience, playing a crucial role in our survival and adaptation to the environment. The study of emotions fosters important applications, such as Human-Computer and Human-Robot interaction or clinical assessment and treatment of mental health conditions such as depression, anxiety, stress, chronic anger, and mood disorders. Listening effort is also an important area of study, as it provides insight into the listeners’ challenges that are usually not identified by traditional audiometric measures. The research is divided into three lines of work, each with a unique emphasis on the methods of emotion elicitation and the stimuli that are most effective in producing emotional responses, with a specific focus on auditory stimuli. The research fostered the creation of three experimental protocols, as well as the use of an available online protocol for studying emotional responses including monitoring of both peripheral and central physiological signals, such as skin conductance, respiration, pupil dilation, electrocardiogram, blood volume pulse, and electroencephalography. An emotional protocol was created for the study of listening effort using a speech-in-noise test designed to be short and not induce fatigue. The results revealed that the listening effort is a complex problem that cannot be studied with a univariate approach, thus necessitating the use of multiple physiological markers to study different physiological dimensions. Specifically, the findings demonstrate a strong association between the level of auditory exertion, the amount of attention and involvement directed towards stimuli that are readily comprehensible compared to those that demand greater exertion. Continuing with the auditory domain, peripheral physiological signals were studied in order to discriminate four emotions elicited in a subject who listened to music for 21 days, using a previously designed and publicly available protocol. Surprisingly, the processed physiological signals were able to clearly separate the four emotions at the physiological level, demonstrating that music, which is not typically studied extensively in the literature, can be an effective stimulus for eliciting emotions. Following these results, a flat-screen protocol was created to compare physiological responses to purely visual, purely auditory, and combined audiovisual emotional stimuli. The results show that auditory stimuli are more effective in separating emotions at the physiological level. The subjects were found to be much more attentive during the audio-only phase. In order to overcome the limitations of emotional protocols carried out in a laboratory environment, which may elicit fewer emotions due to being an unnatural setting for the subjects under study, a final emotional elicitation protocol was created using virtual reality. Scenes similar to reality were created to elicit four distinct emotions. At the physiological level, it was noted that this environment is more effective in eliciting emotions. To our knowledge, this is the first protocol specifically designed for virtual reality that elicits diverse emotions. Furthermore, even in terms of classification, the use of virtual reality has been shown to be superior to traditional flat-screen protocols, opening the doors to virtual reality for the study of conditions related to emotional control

Additional application of the NASCAP code. Volume 1: NASCAP extension

The NASCAP computer program comprehensively analyzes problems of spacecraft charging. Using a fully three dimensional approach, it can accurately predict spacecraft potentials under a variety of conditions. Several changes were made to NASCAP, and a new code, NASCAP/LEO, was developed. In addition, detailed studies of several spacecraft-environmental interactions and of the SCATHA spacecraft were performed. The NASCAP/LEO program handles situations of relatively short Debye length encountered by large space structures or by any satellite in low earth orbit (LEO)

Disentangling the individual and contextual effects of math anxiety: A global perspective

Math anxiety is a common affective disorder in students that is characterized by intrusive thoughts that disrupt critical cognitive resources required for math problem-solving. Consistent associations between math anxiety and math achievement have been observed across countries and age groups, placing math anxiety among other important correlates of math achievement, such as socioeconomic status and magnitude representation ability. However, studies examining math anxiety\u27s relation to achievement have largely focused on the effect of students\u27 own math anxiety (individual effect), while little is known regarding the effect of math anxiety in students\u27 educational context (contextual effect). Using three international studies of achievement (n = 1,175,515), we estimated both the individual and contextual effects of math anxiety across the globe. Results suggest that while there are consistent individual effects in virtually all countries examined, the contextual effects are varied, with only approximately half of the countries exhibiting a contextual effect. Additionally, we reveal that teacher confidence in teaching math is associated with a reduction of the individual effect, and country\u27s level of uncertainty avoidance is related to a lessening of the contextual effect. Finally, we uncovered multiple predictors of math anxiety; notably, student perception of teacher competence was negative related with math anxiety, and parental homework involvement was positively related with math anxiety. Taken together, these results suggest that there are significant between-country differences in how math anxiety may be related with math achievement and suggest that education and cultural contexts as important considerations in understanding math anxiety\u27s effects on achievement