КОНКУРЕНЦІЯ ЗА КУРНО ТА БЕРТРАНОМ В УМОВАХ ПРОСТОРОВОЇ ДУОПОЛІЇ З АСИМЕТРИЧНИМИ РИНКАМИ

Вступ. Після появи знаменитих робіт Курно і Бертрана економісти ось уже більше ста років порівнюють між собою переваги кількісної (за Курно) та ціно- вої (за Бертраном) конкуренції. У класичній моделі дуополії цінова конкурен- ція знижає ціни до рівня граничних витрат (парадокс Бертрана). Споживачі від цього виграють, а фірми отримують мінімальний прибуток. Тому в рамках класичної моделі фірми вважають за краще кількісну конкуренцію. Подолати парадокс Бертрана можливо за умови введення в модель інших характеристик реальних ринків, а саме: продуктової диференціації, динамічної взаємодії фірм, обмеження виробничих потужностей, просторового розташування фірм, тощо. Метою роботи є аналіз моделі просторової дуополії [Liang, W.J., Hwang, H., & Mai, C.C., (2006). Spatial discrimination: Bertrand vs. Cournot with asymmetric demands. Regional Science and Urban Economics, 36, 790–802] в умовах однорідної продукції, асиметрії розмірів ринків та транспортної монопо- лії. З метою максимізації прибутку фірми спочатку вибирають місце розташуван- ня, а потім вид конкуренції – за Курно або Бертраном. У роботі проведено порів- няльний аналіз місць розташування, прибутків, споживчих надлишків і суспільного добробуту в залежності від асиметрії ринків і видів конкуренції. Результати. Отримано, що в стані рівноваги фірми завжди будуть вибирати різні ринки, неза- лежно від виду конкуренції і рівня асиметрії ринків. При відносно малій асиметрії ринків фірми виберуть конкуренцію за Курно. З ростом асиметрії ринків між фір- мами виникне конкуренція за Бертраном-Курно, коли одна фірма оголошує ціну, а інша – обсяг постачань. Конкуренція за Бертраном-Курно призведе до результату конкуренції за Бертраном. Висновки. У роботі показано, що споживчі надлишки і суспільний добробут завжди вище при конкуренції за Бертраном, незалежно від асиметрії ринків. Це означає, що інтереси фірм і споживачів збігаються у виборі оптимальних місць розташування фірм. Проте вибір виду конкуренції при відносно низькому рівні асиметрії розмірів ринків може відрізнятися.

Augmenting Access & Mobility: Designing for the Prosthetic Human

<p>With the needs of the disabled person at the forefront of research and design, this thesis questions how the ‘Prosthetic Human’ can be an architectural catalyst to augment access and mobility. Access and Mobility is identified as an underdeveloped field of architectural enquiry. To improve how disabled individuals experience space, this thesis investigates and tests access and mobility through the lens of design. This thesis extends to the notion of access and networks as defined by Jeremy Rifkin through an architectural exploration into innovation centres. Workplace design strategies directs the design process to formulate stimulating environments that facilitate creative and reflective thought. The theoretical frameworks of Marquard Smith and Joanne Mora, Elizabeth Wright and Mark Wigley, concerning post-human conditions are critically discussed and theoretical notions are transposed into design investigations that explore the building as a prosthetic entity. Specifically, this thesis introduces the disabled body – The Prosthetic Human – as a new figurative referent and proportional system in the design of architecture. Corbusian principles and methods are examined and appropriated for the Prosthetic Human. The proportions of the Prosthetic Human informs the architecture at macro, messo, and micro scales. This research finds that by designing for the Prosthetic Human, the architecture is, holistically representative of a body that requires enhanced access and mobility within space. The research is purposeful; the process celebrates difference and in turn, a calm and embracing architecture is presented in hope for those impaired to be free from spatial discrimination in our environment.</p>

Augmenting Access & Mobility: Designing for the Prosthetic Human

<p>With the needs of the disabled person at the forefront of research and design, this thesis questions how the ‘Prosthetic Human’ can be an architectural catalyst to augment access and mobility. Access and Mobility is identified as an underdeveloped field of architectural enquiry. To improve how disabled individuals experience space, this thesis investigates and tests access and mobility through the lens of design. This thesis extends to the notion of access and networks as defined by Jeremy Rifkin through an architectural exploration into innovation centres. Workplace design strategies directs the design process to formulate stimulating environments that facilitate creative and reflective thought. The theoretical frameworks of Marquard Smith and Joanne Mora, Elizabeth Wright and Mark Wigley, concerning post-human conditions are critically discussed and theoretical notions are transposed into design investigations that explore the building as a prosthetic entity. Specifically, this thesis introduces the disabled body – The Prosthetic Human – as a new figurative referent and proportional system in the design of architecture. Corbusian principles and methods are examined and appropriated for the Prosthetic Human. The proportions of the Prosthetic Human informs the architecture at macro, messo, and micro scales. This research finds that by designing for the Prosthetic Human, the architecture is, holistically representative of a body that requires enhanced access and mobility within space. The research is purposeful; the process celebrates difference and in turn, a calm and embracing architecture is presented in hope for those impaired to be free from spatial discrimination in our environment.</p>

The Impact of Stimulation Intensity on Spatial Discrimination with Multi-Pad Finger Electrode

Multi-pad electrotactile stimulation can be used to provide tactile feedback in different applications. The electrotactile interface needs to be calibrated before each use, which entails adjusting the intensity to obtain clear sensations while allowing the subjects to differentiate between active pads. The present study investigated how the stimulation intensity affects the localization of sensations using a multi-pad electrode placed on a fingertip and proximal phalange. First, the sensation, localization, smearing and discomfort thresholds were determined in 11 subjects. Then, the same subjects performed a spatial discrimination test across a range of stimulation intensities. The results have shown that all thresholds were significantly different, while there was no difference in the threshold values between the pads and phalanges. Despite the subjective feeling of spreading of sensations, the success rates in spatial discrimination were not significantly different across the tested stimulation intensities. However, the performance was better for distal compared to proximal phalange. Presented results indicate that spatial discrimination is robust to changes in the stimulation intensity. Considering the lack of significant difference in the thresholds between the pads, these results imply that more coarse adjustment of stimulation amplitude (faster calibration) might be enough for practical applications of a multi-pad electrotactile interface.

Bitter Taste Disrupts Spatial Discrimination of Piperine-Evoked Burning Sensations: A Pilot Study

This study aimed to investigate the perceptual similarity between piperine-induced burning sensations and bitter taste using piperine-impregnated taste strips (PTS). This pilot study included 42 healthy participants. PTS of six ascending concentrations (1 mg, 5 mg, 10 mg, 15 mg, 20 mg, and 25 mg piperine/dL 96% ethanol) were presented at the anterior tongue, and participants rated perceived intensity and duration. Then, participants performed a spatial discrimination task in which they had to report which of the two strips presented to the anterior tongue contained an irritating stimulus when one strip was always a PTS while the other strip was impregnated with either a single taste quality (sweet or bitter) or a blank strip. Repeated measures one-way ANOVA revealed that burning sensations of higher concentrated PTS were perceived more intense and more prolonged compared to lower concentrated PTS. McNemar’s test showed that PTS were identified correctly significantly less often when presented with bitter strips compared to when presented with blank (p = 0.002) or sweet strips (p = 0.017). Our results showed that bitter taste disrupts the spatial discrimination of piperine-evoked burning sensations. PTS might serve as a basis for further studies on disease-specific patterns in chemosensory disorders.

Tactile spatial discrimination on the torso using vibrotactile and force stimulation

There is a steadily growing number of mobile communication systems that provide spatially encoded tactile information to the humans’ torso. However, the increased use of such hands-off displays is currently not matched with or supported by systematic perceptual characterization of tactile spatial discrimination on the torso. Furthermore, there are currently no data testing spatial discrimination for dynamic force stimuli applied to the torso. In the present study, we measured tactile point localization (LOC) and tactile direction discrimination (DIR) on the thoracic spine using two unisex torso-worn tactile vests realized with arrays of 3 × 3 vibrotactile or force feedback actuators. We aimed to, first, evaluate and compare the spatial discrimination of vibrotactile and force stimulations on the thoracic spine and, second, to investigate the relationship between the LOC and DIR results across stimulations. Thirty-four healthy participants performed both tasks with both vests. Tactile accuracies for vibrotactile and force stimulations were 60.7% and 54.6% for the LOC task; 71.0% and 67.7% for the DIR task, respectively. Performance correlated positively with both stimulations, although accuracies were higher for the vibrotactile than for the force stimulation across tasks, arguably due to specific properties of vibrotactile stimulations. We observed comparable directional anisotropies in the LOC results for both stimulations; however, anisotropies in the DIR task were only observed with vibrotactile stimulations. We discuss our findings with respect to tactile perception research as well as their implications for the design of high-resolution torso-mounted tactile displays for spatial cueing.

Reversal of a Spatial Discrimination Task in the Common Octopus (Octopus vulgaris)

Reversal learning requires an animal to learn to discriminate between two stimuli but reverse its responses to these stimuli every time it has reached a learning criterion. Thus, different from pure discrimination experiments, reversal learning experiments require the animal to respond to stimuli flexibly, and the reversal learning performance can be taken as an illustration of the animal's cognitive abilities. We herein describe a reversal learning experiment involving a simple spatial discrimination task, choosing the right or left side, with octopus. When trained with positive reinforcement alone, most octopuses did not even learn the original task. The learning behavior changed drastically when incorrect choices were indicated by a visual signal: the octopuses learned the task within a few sessions and completed several reversals thereby decreasing the number of errors needed to complete a reversal successively. A group of octopus trained with the incorrect-choice signal directly acquired the task quickly and reduced their performances over reversals. Our results indicate that octopuses are able to perform successfully in a reversal experiment based on a spatial discrimination showing progressive improvement, however, without reaching the ultimate performance. Thus, depending on the experimental context, octopus can show behavioral flexibility in a reversal learning task, which goes beyond mere discrimination learning.

Tactile spatial discrimination on the torso using vibrotactile and force stimulation

There is a steadily growing number of mobile communication systems that provide spatially encoded tactile information to the humans' torso. However, the increased use of such hands-off displays is currently not matched with or supported by systematic perceptual characterization of tactile spatial discrimination on the torso. Furthermore, there are currently no data testing spatial discrimination for dynamic force stimuli applied to the torso. In the present study, we measured tactile point localization (PL) and tactile direction discrimination (DD) on the thoracic spine using two unisex torso-worn tactile vests realized with arrays of 3x3 vibrotactile or force feedback actuators. We aimed to, firstly, evaluate and compare the spatial discrimination of vibrotactile and force stimulations on the thoracic spine and, secondly, to investigate the relationship between the PL and DD results across stimulations. Thirty-four healthy participants performed both tasks with both vests. Tactile accuracies for vibrotactile and force stimulations were 60.7% and 54.6% for the PL task; 71.0% and 67.7% for the DD task, respectively. Performance correlated positively with both stimulations, although accuracies were higher for the vibrotactile than for the force stimulation across tasks, arguably due to specific properties of vibrotactile stimulations. We observed comparable directional anisotropies in the PL results for both stimulations; however, anisotropies in the DD task were only observed with vibrotactile stimulations. We discuss our findings with respect to tactile perception research as well as their implications for the design of high-resolution torso-mounted tactile displays for spatial cueing.