533 research outputs found
A system for synthetic vision and augmented reality in future flight decks
Rockwell Science Center is investigating novel human-computer interaction techniques for enhancing the situational awareness in future flight decks. One aspect is to provide intuitive displays that provide the vital information and the spatial awareness by augmenting the real world with an overlay of relevant information registered to the real world. Such Augmented Reality (AR) techniques can be employed during bad weather scenarios to permit flying in Visual Flight Rules (VFR) in conditions which would normally require Instrumental Flight Rules (IFR). These systems could easily be implemented on heads-up displays (HUD). The advantage of AR systems vs. purely synthetic vision (SV) systems is that the pilot can relate the information overlay to real objects in the world, whereas SV systems provide a constant virtual view, where inconsistencies can hardly be detected. The development of components for such a system led to a demonstrator implemented on a PC. A camera grabs video images which are overlaid with registered information. Orientation of the camera is obtained from an inclinometer and a magnetometer; position is acquired from GPS. In a possible implementation in an airplane, the on-board attitude information can be used for obtaining correct registration. If visibility is sufficient, computer vision modules can be used to fine-tune the registration by matching visual cues with database features. This technology would be especially useful for landing approaches. The current demonstrator provides a frame-rate of 15 fps, using a live video feed as background with an overlay of avionics symbology in the foreground. In addition, terrain rendering from a 1 arc sec. digital elevation model database can be overlaid to provide synthetic vision in case of limited visibility. For true outdoor testing (on ground level), the system has been implemented on a wearable computer
Visual servoing-based augmented reality
The notion of Augmented Reality (AR) is to mix computer-generated, synthetic elements (3D/2D graphics, 3D audio) with real world in such a way that the synthetic elements appear to be part of the real world. There are various techniques to accomplish this, including magnetic tracking of position and orientation, and video-based tracking. This paper focuses on the video-based AR i
The Value of Information and Circular Settings
We present a universal concept for the Value of Information (VoI), based on
the works of Claude Shannon's and Ruslan Stratonovich that can take into
account very general preferences of the agents and results in a single number.
As such it is convenient for applications and also has desirable properties for
decision theory and demand analysis. The Shannon/Stratonovich VoI concept is
compared to alternatives and applied in examples. In particular we apply the
concept to a circular spatial structure well known from many economic models
and allow for various economic transport costs.Comment: 23 pages, 5 figure
Sokpecsétes oklevelek a 14-15. századi Magyarországon
A magyarországi közĂ©pkori pecsĂ©tek közĂĽl a legnagyobb arányban feltáratlan Ă©s közöletlen nemesi pecsĂ©tek, gyűrűspecsĂ©tek összegyűjtĂ©sĂ©nek elsĹ‘ lĂ©pĂ©sekĂ©nt magátĂłl Ă©rtetĹ‘dĹ‘en adĂłdik az Ăşn. sokpecsĂ©tes (legalább tĂz pecsĂ©tlenyomatot hordozĂł) oklevelek feldolgozása. Az aljukra fĂĽggesztett pecsĂ©tek sorával ezek az oklevelek igen látványosak. Többnyire nemzetközi vonatkozásĂş örökösödĂ©si-, házassági-, bĂ©keszerzĹ‘dĂ©seket foglalnak Ărásba, vagy azoknak az országnagyok, a magyarországi rendek általi megerĹ‘sĂtĹ‘ oklevelei. A magyarországi vonatkozásĂşaknak is tĂşlnyomĂł többsĂ©ge kĂĽlföldi levĂ©ltárakban találhatĂł. A tanulmány az 1304 Ă©s 1511 között ĂrĂłdott, harmincnál több sokpecsĂ©tes oklevĂ©l mintegy 910-et kitevĹ‘ pecsĂ©tanyagának statisztikai jellemzĹ‘it Ă©s változásait mutatja be az ábrázolási tĂpus, a cĂmertan, az epigráfia szempontjábĂłl. A vizsgált oklevelek többsĂ©ge a bĂ©csi, több oklevĂ©l a varsĂłi Ă©s a budapesti állami levĂ©ltárakban, egy pedig Dubrovnikban találhatĂł
Continuous phase transitions with a convex dip in the microcanonical entropy
The appearance of a convex dip in the microcanonical entropy of finite
systems usually signals a first order transition. However, a convex dip also
shows up in some systems with a continuous transition as for example in the
Baxter-Wu model and in the four-state Potts model in two dimensions. We
demonstrate that the appearance of a convex dip in those cases can be traced
back to a finite-size effect. The properties of the dip are markedly different
from those associated with a first order transition and can be understood
within a microcanonical finite-size scaling theory for continuous phase
transitions. Results obtained from numerical simulations corroborate the
predictions of the scaling theory.Comment: 8 pages, 7 figures, to appear in Phys. Rev.
Plasma testosterone and androstenedione levels follow the same sex-specific patterns in the two Pan species
In most animals, males are considered more aggressive, in terms of frequency and intensity of aggressive behaviors, than their female peers. However, in several species this widespread male-biased aggression pattern is either extenuated, absent, or even sex-reversed. Studies investigating potential neuro-physiological mechanisms driving the selection for female aggression in these species have revealed an important, but not exclusive role of androgens in the expression of the observed sex-specific behavioral patterns. Two very closely related mammalian species that markedly differ in the expression and degree of sex-specific aggression are the two Pan species, where the chimpanzee societies are male-dominated while in bonobos sex-biased aggression patterns are alleviated. Using liquid chromatography–mass spectrometry (LC-MS) methods, we measured levels of plasma testosterone and androstenedione levels in male and female zoo-housed bonobos (N = 21; 12 females, 9 males) and chimpanzees (N = 41; 27 females, 14 males). Our results show comparable absolute and relative intersexual patterns of blood androgen levels in both species of Pan. Plasma testosterone levels were higher in males (bonobos: females: average 0.53 ± 0.30 ng/mL; males 6.70 ± 2.93 ng/mL; chimpanzees: females: average 0.40 ± 0.23 ng/mL; males 5.84 ± 3.63 ng/mL) and plasma androstenedione levels were higher in females of either species (bonobos: females: average 1.83 ± 0.87 ng/mL; males 1.13 ± 0.44 ng/mL; chimpanzees: females: average 1.84 ± 0.92 ng/mL; males 1.22 ± 0.55 ng/mL). The latter result speaks against a role of androstenedione in the mediation of heightened female aggression, as had been suggested based on studies in other mammal species where females are dominant and show high levels of female aggressivenes
Blood testosterone levels in sickness and in health: Male chimpanzee testosterone levels decrease in face of an immune challenge
As an integral part of the immune response, testosterone secretion is inhibited when an individual is confronted with an immune challenge. Testosterone-mediated physiological, morphological, and behavioral traits are compromised at times of impaired health. Nevertheless, males of some species seem to maintain high levels of testosterone when confronted with an immune challenge, upholding competitive strength but compromising their immune response. It has been argued that this phenomenon will occur only in species living in social systems with high degrees of male-male competition over mating opportunities. Male chimpanzees contest over access to fertile females and dominants sire the majority of offspring. This male mating pattern makes chimpanzees a candidate species where we could expect males to maintain high testosterone levels, compromising their immune response, to ensure immediate reproductive success. We measured blood testosterone levels in male and female chimpanzees, who expressed clinical symptoms (symptomatic) or showed no evidence of clinical disease on assessment (asymptomatic). For females, we expected to find lower testosterone levels in symptomatic individuals than in asymptomatic subjects. In males, we would predict lower testosterone levels in symptomatic individuals than in asymptomatic males, if the immune response leads to a decrease in testosterone secretion. Alternatively, males could have equal levels of testosterone when symptomatic and asymptomatic, upholding competitive strength. Our results show that male chimpanzees exhibit lower levels of testosterone when confronted with an immune challenge than when being asymptomatic. This suggests that male testosterone secretion is suppressed as part of the immune response, which potentially increases survival and lifetime reproductive success. It will, however, negatively impact momentary competitive ability. Also, males may employ different mating strategies, some of which are less testosterone-driven (e.g., affiliative strategies). Consequently, in some individuals, the costs of maintaining high testosterone levels may not outweigh the potential gain in reproductive success
Testing the effect of medical positive reinforcement training on salivary cortisol levels in bonobos and orangutans
The management of captive animals has been improved by the establishment of positive reinforcement training as a tool to facilitate interactions between caretakers and animals. In great apes, positive reinforcement training has also been used to train individuals to participate in simple medical procedures to monitor physical health. One aim of positive reinforcement training is to establish a relaxed atmosphere for situations that, without training, might be very stressful. This is especially true for simple medical procedures that can require animals to engage in behaviours that are unusual or use unfamiliar medical devices that can be upsetting. Therefore, one cannot exclude the possibility that the training itself is a source of stress. In this study, we explored the effects of medical positive reinforcement training on salivary cortisol in two groups of captive ape species, orangutans and bonobos, which were familiar to this procedure. Furthermore, we successfully biologically validated the salivary cortisol assay, which had already been validated for bonobos, for orangutans. For the biological validation, we found that cortisol levels in orangutan saliva collected during baseline conditions were lower than in samples collected during three periods that were potentially stressful for the animals. However, we did not find significant changes in salivary cortisol during medical positive reinforcement training for either bonobos or orangutans. Therefore, for bonobos and orangutans with previous exposure to medical PRT, the procedure is not stressful. Thus, medical PRT provides a helpful tool for the captive management of the two species
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