250 research outputs found
Young Scientists: Development of an Interactive STEM Program for Students at Vermillion “Beyond School Adventures
STEM (science, technology, engineering and mathematics) education is of increasing importance in our society. Advancements in technology, a growing need for new ideas in engineering and mathematics, and greater emphasis on science have all contributed to the renewed focus on STEM education. It is crucial that children develop an appreciation and enthusiasm for STEM at a young age. Fostering curiosity in students is a valuable investment in their personal future and the future of our world. The purpose of this thesis project was to design and implement an interactive STEM program for the after-school program, Beyond School Adventures in Vermillion, SD. This program consists of six fun, hands-on, and unique STEM activities for kindergarten and first-grade students; specifically, modules on solar heat, growing a plant, habitats, the science of sounds, engineering a communication device, and exploring plants.  Each module involves a short background presentation of the topic being explored, an opportunity for each student to do the activity, and a take-home component for extended learning and sharing of their new understanding. This project involved the development, funding, testing, revision of the modules, and presentation to the students. In future years, this project will be sustained as an outreach program of the USD Biology Club
Light as a true visual quantity : principles of measurement
This Technical Report summarizes visual photometric measurement methods which can provide visually meaningful assessments of light. They can be more complicated than the simple use of of a V(?)-corrected physical photometer, and in addition require some understanding of the visual system and how it works. Their advantage is that the assessment of light bears a logical relationship to the human perception of light. For photopic vision and luminances larger than several cd/m2, ordinary physical photometers corrected to V(?) give visually accurate measures for small, centrally fixed, broad-band lights. For other applications, a different luminous efficiency function should be employed. In order to utilize the appropriate function, one must either measure the spectral distribution of radiant power directly or correct the V(?) response of the photometer to the appropriate luminous efficiency. An alternative solution is to calculate mathematical formulas specifically developed for this purpose. This method is potentially the most useful since different formulas can be developed for different applications (for example, two degree or ten degree fields). It is based on established CIE data, and no additional measures need to be developed.For scotopic vision, an assessment of radiant power is made with respect to the scotopic luminous efficiency function V'(?) by means of an appropriately corrected physical photometer, by radiance measurement, or by visual photometry. In mesopic photometry, the photopic and scotopic contributions of the light must be assessed. An estimate can be obtained by combining the photopic and scotopic luminances non-linearly. A more precise measure can be obtained by using three or, still better, four quantities based on X10, Y10, Z10, and V'(?)
Towards linking perception research and image quality
Image quality as a general notion relates both to elementary and to complex visual functions. In this paper we deal with a few of them, which correspond to some lines of research at our Institute. We start with threshold predictions in time and space domains by means of elementary response functions, which have been recently developed considerably, although full generalization has not yet been achieved. As to suprathreshold stimuli, the responses of subjects usually have to be scaled. Here we deal with some problems connected with scaling techniques. After a brief discussion of the applicability of notions on visual conspicuity and visual search to image quality problems, we finally discuss reading from alphanumeric displays
Temporal impulse and step responses of the human eye obtained psychophysically by means of a drift-correcting perturbation technique
Internal impulse and step responses are derived from the thresholds of short probe flashes by means of a drift-correcting perturbation technique. The approach is based on only two postulated systems properties: quasi-linearity and peak detection. A special feature of the technique is its strong reduction of the concealing effect of sensitivity drift within and between sessions. Results were found to be repeatable, even after about one year. For a 1° foveal disk at 1200 td stationary level, impulse responses of increments and decrements were found to be mirror-symmetrical. They were equal to the derivatives of the measured step responses. As a consequence the threshold of any fast-changing retinal illumination should be predictable. This will be tested in a subsequent paper. The transfer function of the system responding to a 1° stimulus shows a band-pass filter type of processing for transients, confirming quantitatively earlier findings. In contrast, a foveal point source on an extended background of 1200 td, to which impulse and step responses appear also to be linearly related, gives rise to low-pass filter action of the system
The foveal point spread function as a determinant for detail vision
A point spread function, chosen to link contrast sensitivity and stimulus dimensions, can be obtained from measured thresholds by assuming small-signal-linearity and peak detection for the visual system. To that end a special case of summation of subthreshold signals (perturbation) is used, taking specific measures against the effect of sensitivity drift. The basic assumptions are tested simultaneously and confirmed. Other provisional assumptions like radial symmetry and homogeneity were evaluated along a horizontal and a vertical meridian through the fovea. In the fovea no deviation from radial symmetry was found. The effect of inhomogeneity within the central fovea. seems to be too small to cause a significant change in the point spread function. The validity for predicting thresholds of stimuli exposing larger areas is tested. Annuli with varying radii show no significant aberration if probability summation is taken into account. Predicted disk thresholds, however, show a large discrepancy with experiment for radii larger than 2 min arc. A possible extension of the model with multiple-detection units having tuned sizes is evaluated
Temporal impulse and step responses of the human eye obtained psychophysically by means of a drift-correcting perturbation technique
Esprit du don, dispositifs et reconnaissance : de "Diaries, Notes and Sketches : Also Known as Walden" (1969) Ă "The First Forty" (2006) de Jonas Mekas
Après avoir passé plus de 4 ans dans des camps de travail forcé, Jonas Mekas, lituanien, est déporté avec son frère par les Nations-Unies en 1949 aux États-Unis. Les deux rescapés de la seconde guerre mondiale dédient alors leur temps au cinéma. Dès leur arrivée, ils se procurent une caméra 16 mm bolex et se tournent vers le cinéma expérimental, grâce, entre autre, à une de ces cinéastes pionnières américaine Maya Deren. En marge de l'industrie cinématographique hollywoodienne, Jonas Mekas participe à l'édification de structures - coopératives, associations, magazines, journaux - afin de rendre accessible ce genre filmique, de lui obtenir une reconnaissance publique et de, ultimement, le préserver. En 1969, il réalise un film intitulé "Diaries, Notes and Sketches : Also Known as Walden". Mekas réalise ensuite des films qui réemploient des séquences qui se trouvent dans cette première ébauche filmique. Ce processus se retrace au sein de son « premier essai » numérique qu'il réalise à l'ère cybériste intitulé "The First Forty" (2006), composé de vidéos et de descriptions textuelles. Tout comme il l’avait fait avec Walden, Mekas présente explicitement celui-ci à un public, en l’occurrence son nouveau public d'internautes, qui en prend connaissance sur son site web officiel. La présentation numérique et la table des matières papier accompagnant "Diaries, Notes and Sketches : Also Known as Walden" rédigée par l'artiste en 1969 ont une fonction similaire au sens où, par elles, Jonas Mekas donne ces deux créations aux spectateurs. Nous avons choisi d'employer le terme de dispositif pour parler de ces « objets » qui font appel à diverses formes énonciatives afin de créer un effet spécifique chez le spectateur. En explorant la théorie sociologique moderne du don développée par Jacques T. Godbout, notre projet a été de relever « l'esprit de don » qui se retrace au sein de ces dispositifs. Cette étude nous permet de constater que les dispositifs audiovisuels / cinématographiques que développa Mekas sont des « objets » qui peuvent être reçus tel des dons suscitant le désir de donner chez les spectateurs. Ils sont le ciment symbolique personnel et collectif nécessaire à l’accomplissement du processus de « reconnaissance » qu’implique le don.Having spent more than 4 years in camps of forced labor, Jonas Mekas, Lithuanian, is deported by the United-Nations in 1949 to the United States. With his brother, both survivors of the Second World War, they manage to acquire a bolex 16 mm camera. Outside the Hollywood cinematographic industry, Mekas participates to the institutionalization of the underground artistic community by creating cooperatives, associations and magazines. Mekas is devoting his time to make experimental film genre accessible and allows it to become publicly recognized for its artistic value, which would lead towards protecting and preserving it. In 1969, Mekas produced "Diaries, Notes and Sketches: Also Known has Walden" which condense 4 years of capturing everyday events, people, New York, nature. From his Walden, Mekas will reuse some sequences found in this first draft when comes the time to edit new films. In 2006, Mekas produces his “first digital essay” entitled "The First Forty" (2006). It consists in a presentation of his cinematic labor to a new public, his “new Internet Audience”, in which sequences of Walden appear. Accessible on his official website, this digital piece is composed by videos and their textual descriptions, reminding us of Diaries, Notes and Sketches: Also Known has Walden and its table of content drafted by the artist in 1969. These two apparatus have a similar function : by them, Jonas Mekas explicitly gives these two pieces to the spectators. By investigating the sociological “gift theory” developed by the Jacques T. Godbout, our project was to reveal how “the gift spirit" can be found within those two creations. This study allows us to believe that audiovisual/cinematographic apparatus created by Mekas are “objects” which can be received such as gifts leading to arrouse the spectator’s desire to give in his turn. In this way, they are personal and collective symbolic cement necessary for the fulfillment of the process of “recognition” which involves the gift spirit
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