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Advances in simulation technology have brought about many improvements to the way we train tasks, as well as how we perform tasks in the operational field. Augmented reality (AR) is an example of how to enhance the user's experience in the real world with computer generated information and graphics. Visual search tasks are known to be capacity demanding and therefore may be improved by training in an AR environment. During the experimental task, participants searched for enemies (while cued from visual, auditory, tactile, combinations of two, or all three modality cues) and tried to shoot them while avoiding shooting the civilians (fratricide) for two 2-minute low-workload scenarios, and two 2-minute high-workload scenarios. The results showed significant benefits of attentional cuing on visual search task performance as revealed by benefits in reaction time and accuracy from the presence of the haptic cues and auditory cues when displayed alone and the combination of the visual and haptic cues together. Fratricide occurrence was shown to be amplified by the presence of the audio cues. The two levels of workload produced differences within individual's task performance for accuracy and reaction time. Accuracy and reaction time were significantly better with the medium cues than all the others and the control condition during low workload and marginally better during high workload. Cue specificity resulted in a non-linear function in terms of performance in the low workload condition. These results are in support of Posner's (1978) theory that, in general, cueing can benefit locating targets in the environment by aligning the attentional system with the visual input pathways. The cue modality does not have to match the target modality. This research is relevant to potential applications of AR technology. Furthermore, the results identify and describe perceptual and/or cognitive issues with the use of displaying computer generated augmented objects and information overlaid upon the real world. The results also serve as a basis for providing a variety of training and design recommendations to direct attention during military operations. Such recommendations include cueing the Soldier to the location of hazards, and mitigating the effects of stress and workload.

<p> This dissertation brings the insights of linguistic discourse analysis, and particularly of Systemic Functional Linguistics (SFL), to bear on the prophetic book of Joel in order to clarify the nature and function of the Day of YHWH in the book. The concepts of register and genre as defined by SFL, along with the related concepts of context of situation, context of culture, and context of text (or co-text), provide helpful tools that both dovetail with the problems and goals of other kinds of synchronic analysis and give new and valuable insights. By applying register analysis to the various passages that deal with the Day of YHWH in the book of Joel, the dissertation identifies the registers of the four sections of the book and compares and contrasts the various registers of each of these sections, making use of this analysis to shed light on the nature and function of the Day of YHWH in each section. Following this is a description of the linguistic register, the context of situation, and the nature and function of the Day of YHWH in the book of Joel as an entire text.</p> <p> The Day of YHWH in the book of Joel is a future moment of theophanic intervention, an inevitable day of destruction and salvation. Key to the theology of the Day of YHWH in Joel is the relational orientation of the readers/hearers of the book to YHWH. The book of Joel is thus a communicative act that calls for repentance grounded in worship of YHWH and that promises deliverance from the Day and a glorious eschatological future for those who heed the book's call to proper orientation toward YHWH.</p> / Thesis / Doctor of Philosophy (PhD)

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Optical trackers are often used at the Air Force Flight Test Center (AFFTC) and at other Department of Defense (DoD) ranges to collect video and trajectory data for real-time display and postflight processing. When optical trackers are used in remote areas, pointing data from radar is utilized to enable the trackers to initially acquire targets. To enable the trackers to use radar-pointing data, offsets to true north must first be known. This offset is taken into account given the current position of the optical tracker. During postflight processing, when determining the trajectory of the target, the offsets are also taken into account to produce an accurate trajectory solution. Current methods of determining offsets to true north are time consuming and involve a lot of guesswork. Typically, a map and a known landmark are used to determine the offsets to true north. Another method is to look for the North Star (Polaris) and input an estimated offset. This paper will describe an inexpensive, stand-alone system that utilizes the Global Positioning System (GPS) to determine these offsets. This device may be modified and integrated with other systems that may need to point accurately. For example, a gun barrel on a tank may need to point accurately to within a degree. This device may also be used to accurately position telemetry antennas.

O teste de atenção encoberta descrito por Posner (1980) vem sendo intensamente utilizado em estudos sobre orientação da atenção visuo-espacial em seres humanos. Mais recentemente, esse teste foi adaptado para avaliação da atenção em ratos, com resultados entusiasmantes, pois parece haver uma analogia entre os fenômenos atencionais envolvendo seres humanos e ratos (ROSNER; MITTLEMAN, 1996; WARD; BROWN, 1996; LUCK E VECERA, 2002). A distinção entre orientação exógena (ou \"automática\", na literatura envolvendo humanos) e endógena (ou \"voluntária\", na literatura envolvendo humanos) da atenção, postuladas principalmente com base nas diferenças do curso temporal da resposta ao alvo visual, foram em parte descritas em ratos; esses trabalhos iniciais sugeriam apenas a ocorrência de respostas automáticas em ratos. Porém, Marote e Xavier (2011) mostraram efeito de validade quando pistas preditivas e não-preditivas precediam o alvo em 200, 400 e 800 ms; porém, esse efeito foi maior quando as pistas preditivas precederam o alvo em 800 ms, o que em humanos é tido como efeito da orientação voluntária da atenção. Dado que na maioria dos estudos envolvendo ratos a pista utilizada é periférica, torna-se difícil distinguir claramente entre a ocorrência de efeitos exógenos e efeitos endógenos da orientação da atenção. No presente estudo avaliamos a orientação encoberta da atenção visuo-espacial em ratos empregando pistas simbólicas preditivas, isto é, um tipo de pista que, em seres humanos, restringiria a orientação da atenção apenas ao componente voluntário. Os resultados mostraram que ratos exibem redução do tempo de reação e aumento na percentagem de respostas corretas a um alvo visual precedido por pista simbólica auditiva preditiva válida em relação à pista inválida. Esse efeito manifestou-se quando o intervalo entre a pista e o alvo foi de 100 ou de 700 ms, mas não quando foi de 400 ms. Esses resultados sugerem a existência de dois tipos de fenômenos usualmente atribuídos à orientação da atenção visuo-espacial, o primeiro determinado pelos efeitos do pareamento repetitivo entre a pista e o alvo (que talvez envolva condicionamento clássico), que se manifesta quando o intervalo entre esses estímulos é da ordem de 100 ms, e o segundo determinado pela orientação endógena da atenção, que se manifesta quando o intervalo é igual ou maior que 700 ms. / The covert orienting of attention task described by Posner (1980) has been extensively used for investigating orientation of visuo-spatial attention in humans. There have been attempts to adapt it for rats, with encouraging results; data revealed that attentional phenomena in humans and rats are partially analogous (ROSNER, MITTLEMAN, 1996; WARD, BROWN, 1996; LUCK and VECERA, 2002). The distinction between exogenous (or \"automatic\", in human literature) and endogenous (or \"voluntary\", in human literature) orienting of attention, relying mainly on differences in the time course of the reaction time to the visual target, was partially described for rats; these early studies indicated that rats exhibited only the automated component of orienting. However, Marote and Xavier (2011) showed validity effects when using either predictive or non-predictive cues preceding the target by 200, 400 and 800 ms; however, this validity effect was greater for predictive cues preceding the target by 800 ms, a result that in human studies is taken as evidence of voluntary orienting of attention. Most of rat studies using this task employ peripheral cues, rendering difficult to distinguish exogenous and endogenous effects of orienting of attention. In the present study orienting of visuo-spatial attention was investigated in rats by using symbolic predictive cues, a kind of cue usually considered to engage voluntary attention in humans. The results showed that rats exhibit a reduction of reaction times and an increase in percentage of correct responses to a visual target preceded by a valid symbolic auditory predictive cue as compared to an invalid cue, when the stimulus onset asynchrony was either 100 or 700 ms, but not when it was 400 ms. These figures suggest that the validity effect in rats is underlied by at least two processes, the first determined by repetitive and contingent cue-target pairings (that might involve classical conditioning) that occurs when the cue-target time interval is about 100 ms, and the second determined by endogenous orienting of attention that occurs when the cue-target time interval is about 700 ms.

A functional and effective alarm signal is a critical component of alarm systems designed to alert workers of impending danger. In a previous study (Hansson, 2017) background alarm sirens composed of changing-state sounds with an embedded temporal deviant, produced greater disruption of serial short-term memory than a signal without a deviant. However, to give rise to disruption the siren needed to change from fast to slow, since a change from slow to fast was impotent in its effect on task performance. In the current study, whether acoustic change was a necessary prerequisite for obtaining the fast-to-slow deviant effect was explored. Thus, repeated tones—steady-state sequences—presented at slow or fast rates were used with or without a temporal deviant (change from slow-to-fast vs. change from fast-to-slow). In the context of the steady-state sequences, both slow-to-fast and fast-to-slow temporal deviants produced disruption relative to the fast and slow control sequences. This suggests that a changing-state sequence is required for the fast-to-slow temporal deviant effect to arise. However, an alternative explanation based upon inter-stimulus intervals is also entertained. Understanding the acoustic parameters of sound is necessary to develop alarms sirens that are better at capturing attention. The current study suggests that embedding temporal deviants within sirens can promote greater attentional capture, but that this may depend on the nature of the alarm signal (whether it is changing vs. steady-state) and the direction of the change of speed (slow-to-fast vs. fast-to-slow).

Alarm signals such as sirens are crucial in alerting users of impending dangers. Therefore, it is important that the siren is designed so it can capture user's attention. In a previous study (Hansson, 2017) background alarm sirens composed of changing-state sounds with an embedded temporal deviant, produced greater disruption of serial short-term memory than a signal without a temporal deviant. However, to give rise to disruption the siren needed to change from fast to slow, since a change from slow to fast was impotent in its effect on task performance. This was further addressed in Hansson (2018) where it was shown that acoustic change appeared to be a necessary prerequisite for obtaining the fast-to-slow temporal deviant effect: When steady-state sounds were used fast-to-slow and or slow-to-fast temporal deviants were equally disruptive of serial recall. However, in order to create a steady-state siren, inter-stimulus intervals were incorporated into the siren to prevent the continuous uninterrupted presentation of a single tone. Since inter-stimulus intervals were not used in Hansson (2017) it could be the presence of these that eliminated the potency of the fast-to-slow over the slow-to-fast temporal deviation effect in Hansson (2018). Therefore, the current study was undertaken to investigate whether the embedding inter-stimulus intervals within a changing-state siren would restore the potency of the fast-to-slow temporal deviation over the slow-to-fast temporal deviation in capturing attention. The additional disruption for fast-to-slow temporal deviants over slow-to-fast temporal deviants (that did not produce disruption relative to control) returned in the current study when inter-stimulus intervals were included within the siren. The results support the notion that the additional disruption produced by fast-to-slow, over slow-to-fast temporal deviants depend on the changing-state properties of the siren. Implications of this result for the design and operation of sirens within ecologically valid settings are discussed.

Foi investigado o curso temporal da orientação da atenção numa tarefa de orientação encoberta adaptada para ratos. A tarefa envolveu a avaliação do efeito de pistas auditivas centrais e periféricas, preditivas ou não preditivas, sob o tempo de reação a alvos visuais apresentados à direita ou à esquerda do campo visual. Foram utilizados tempos entre pista e alvo (SOAs) entre 50 a 1200 ms. Pistas centrais consistiram em bipes de 5 ou 8 kHz reproduzidos em ambos ouvidos concomitantemente. Neste caso a frequência do bipe indicava o lado para o qual a atenção deveria ser orientada. Pistas periféricas constituíram-se de bipes de 5 ou 8 kHz, apresentados individualmente no ouvido esquerdo ou direito. Neste caso o lado da apresentação do estímulo indicava a direção para a qual o animal deveria orientar a atenção. Esses estímulos foram apresentados de forma preditiva - em 80% das tentativas as pistas indicavam corretamente a localização do alvo (tentativas válidas) e em 20% o indicavam incorretamente (tentativas inválidas) - ou não preditiva - 50% de tentativas válidas e 20% de tentativas inválidas - a depender do grupo. Vinte e quatro ratos Wistar machos, com 3 meses no início dos experimentos, divididos em quatro grupos experimentais independentes - Central Preditivo (CP), Central Não Preditivo (CNP), Periférico Preditivo (PP) e Periférico Não Preditivo (PNP) - foram empregados. Os resultados mostram que animais dos grupos preditivos (CP e PP) respondem mais rapidamente e de forma mais precisa em tentativas válidas do que em tentativas inválidas, ao passo que animais em grupos não preditivos (CNP e PNP) respondem da mesma maneira em tentativas válidas ou inválidas. Esses resultados indicam de estes animais foram capazes de orientar a atenção de forma endógena, de forma análoga a seres humanos, sugerindo que ratos podem ser empregados amplamente como modelo animal na avaliação das orientações endógena e exógena da atenção / Orienting of visual attention was investigated in rats using a 3-hole nose-poke task analogous to the covert attention task for humans. The task involved evaluation of the effects of either central or peripheral auditory cues, presented either predictively or non-predictively on reaction times to a visual target presented either to the left or to the right sides of the visual field; stimuli-onset asynchronies (SOAs) varied from 50 to 1200 ms. Central cues were either 5 or 8 KHz auditory stimuli, released on both ears concomitantly. In this case, the frequency indicated the side to which attention should be oriented to. Peripheral cues were 5 and 8 KHz auditory stimuli presented individually either to the left or to the right ears. In this case, the sound source indicated to which side attention should be oriented to. These stimuli were presented either predictively - 80% of cues predicted the target\'s location correctly (valid trials) and 20% of cues predicted it incorrectly (invalid trials) - or non-predictively - 50% of valid trials and 50% invalid trials - depending on the group. Twenty-four male Wistar rats, 3 month-old at the beginning of the experiment, divided in four independent groups - Central Predictive (CP), Central Non-Predictive (CNP), Peripheral Predictive (PP) and Peripheral Non-Predictive (PNP) - were employed. Animals on predictive groups (CP and PP) showed faster and more accurate responses on valid trials than on invalid trials, while non-predictive groups (CNP and PNP) didn\'t show any differences on reaction times and accuracy in valid as compared to invalid trials. These results indicate that rats do orient attention endogenously, analogously to humans. This suggests that these animals may be employed as animal model to the study of endogenous and exogenous orienting of attention

Current models of visual spatial attention are based on the extent to which attention can be allocated in 2-dimensional displays. The distribution of attention in 3-dimensional space has received little consideration. A series of experiments were devised to explore the apparent inconsistencies in the literature pertaining to the allocation of spatial attention in the third dimension. A review of the literature attributed these inconsistencies to differences and limitations in the various methodologies employed, in addition to the use of differing attentional paradigms. An initial aim of this thesis was to develop a highly controlled novel adaptation of the conventional robust covert orienting of visual attention task (COVAT) in depth defined by either binocular (stereoscopic) or monocular cues. The results indicated that attentional selection in the COVAT is not allocated within a 3-dimensional representation of space. Consequently, an alternative measure of spatial attention in depth, the overlay interference task, was successfully validated in a different stereoscopic depth environment and then manipulated to further examine the allocation of attention in depth. Findings from the overlay interference experiments indicated that attentional selection is based on a representation that includes depth information, but only when an additional feature can aid 3D selection. Collectively, the results suggest a dissociation between two paradigms that are both purported to be measures of spatial attention. There appears to be a further dissociation between 2-dimensional and 3-dimensional attentional selection in both paradigms for different reasons. These behavioural results, combined with recent electrophysiological evidence suggest that the temporal constraints of the 3D COVAT paradigm result in early selection based predominantly on retinotopic spatial coordinates prior to the complete construction of a 3-dimensional representation. Task requirements of the 3D overlay interference paradigm, on the other hand, while not being restricted by temporal constraints, demand that attentional selection occurs later, after the construction of a 3-dimensional representation, but only with the guidance of a secondary feature. Regardless of whether attentional selection occurs early or late, however, some component of selection appears to be based on viewer-centred spatial coordinates.

A method is presented for stably grasping 2 dimensional polygonal objects with a dextrous hand when object models are not avaiable. Basic constraints on object vertex angles are found for feasible grasping with two fingers. Local tactile information can be used to determine the finger motion that will reach feasible grasping locations. With an appropriate choice of finger stiffness, a hand can automatically grasp these objects with two fingers. The bounded slip of a part in a hand is shown to be valuable for adapting the fingers and object to a stable situation. Examples are given to show the ability of this grasping method to accomodate disturbance forces and to perform simple part reorientations and regrasping operations.