The (a,b,s,t)-diameter of graphs: a particular case of conditional diameter

The conditional diameter of a connected graph $\Gamma=(V,E)$ is defined as follows: given a property ${\cal P}$ of a pair $(\Gamma_1, \Gamma_2)$ of subgraphs of $\Gamma$, the so-called \emph{conditional diameter} or ${\cal P}$-{\em diameter} measures the maximum distance among subgraphs satisfying ${\cal P}$. That is, $$D_{{\cal P}}(\Gamma):=\max_{\Gamma_1, \Gamma_2\subset \Gamma} \{\partial(\Gamma_1, \Gamma_2): \Gamma_1, \Gamma_2 \quad {\rm satisfy }\quad {\cal P}\}.$$ In this paper we consider the conditional diameter in which ${\cal P}$ requires that $\delta(u)\ge \alpha$ for all $u\in V(\Gamma_1)$, $\delta(v)\ge \beta$ for all $v\in V(\Gamma_2)$, $| V(\Gamma_1)| \ge s$ and $| V(\Gamma_2)| \ge t$ for some integers $1\le s,t\le |V|$ and $\delta \le \alpha, \beta \le \Delta$, where $\delta(x)$ denotes the degree of a vertex $x$ of $\Gamma$, $\delta$ denotes the minimum degree and $\Delta$ the maximum degree of $\Gamma$. The conditional diameter obtained is called $(\alpha ,\beta, s,t)$-\emph{diameter}. We obtain upper bounds on the $(\alpha ,\beta, s,t)$-diameter by using the $k$-alternating polynomials on the mesh of eigenvalues of an associated weighted graph. The method provides also bounds for other parameters such as vertex separators

Sex-related differences in chromatic sensitivity

Generally women are believed to be more discriminating than men in the use of colour names and this is often taken to imply superior colour vision. However, if both X-chromosome linked colour deficient males (~8%) and females (<1%) as well as heterozygote female carriers (~15%) are excluded from comparisons, then differences between men and women in red-green colour discrimination have been reported as not being significant (e.g., Pickford, 1944; Hood et al., 2006). We re-examined this question by assessing the performance of 150 males and 150 females on the Colour Assessment and Diagnosis (CAD) test (Rodriguez-Carmona, 2005). This is a sensitive test that yields small colour detection thresholds. The test employs direction-specific, moving, chromatic stimuli embedded in a background of random, dynamic, luminance contrast noise. A four-alternative, forced-choice procedure is employed to measure the subject’s thresholds for detection of colour signals in 16 directions in colour space, while ensuring that the subject cannot make use of any residual luminance contrast signals. In addition, we measured the Rayleigh anomaloscope matches in a subgroup of 111 males and 114 females. All the age-matched males (30.8 ± 9.7) and females (26.7 ± 8.8) had normal colour vision as diagnosed by a battery of conventional colour vision tests. Females with known colour deficient relatives were excluded from the study. Comparisons between the male and female groups revealed no significant differences in anomaloscope midpoints (p=0.709), but a significant difference in matching ranges (p=0.040); females on average tended to have a larger mean range (4.11) than males (3.75). Females also had significantly higher CAD thresholds than males along the red-green (p=0.0004), but not along the yellow-blue discrimination axis. The differences between males and females in red-green discrimination may be related to the heterozygosity in X-linked cone photopigment expression common among females

Early forest fire detection by vision-enabled wireless sensor networks

Wireless sensor networks constitute a powerful technology particularly suitable for environmental monitoring. With regard to wildfires, they enable low-cost fine-grained surveillance of hazardous locations like wildland-urban interfaces. This paper presents work developed during the last 4 years targeting a vision-enabled wireless sensor network node for the reliable, early on-site detection of forest fires. The tasks carried out ranged from devising a robust vision algorithm for smoke detection to the design and physical implementation of a power-efficient smart imager tailored to the characteristics of such an algorithm. By integrating this smart imager with a commercial wireless platform, we endowed the resulting system with vision capabilities and radio communication. Numerous tests were arranged in different natural scenarios in order to progressively tune all the parameters involved in the autonomous operation of this prototype node. The last test carried out, involving the prescribed burning of a 95 x 20-m shrub plot, confirmed the high degree of reliability of our approach in terms of both successful early detection and a very low false-alarm rate. Journal compilationMinisterio de Ciencia e Innovación TEC2009-11812, IPT-2011-1625-430000Office of Naval Research (USA) N000141110312Centro para el Desarrollo Tecnológico e Industrial IPC-2011100

Spades, Actors and Fags: Fiction and/as Queer Theory in Timothy Findley’s Spadework

[Abstract] This paper analyses Timothy Findley’s last novel, Spadework (2002 [2001] ), to engage the relevance of Gender/Queer Theory as a visible intertext. As we read, it seems apparent that that Spadework provides a further turn of the screw to invigorate the gendermarked fiction/theory popular in Canadian writing. Issues of gender/sex performativity and performance, in several ways, populate the novel, which, as a whole, is a critique of identity very close to the one proposed by Queer Theory models, usually oriented to interrogate normativity and the identities that it produces

A dark night of the soul: sexuality, subjectivity and autobiographical modes in Marian Engel's "The glassy sea"

Marian Engel ’s novel The Glassy Sea (1978) features a woman in search of a creative and experiential voice through a complex process of individuation. This coming to terms with her self is doubly complicated, since the protagonist, the Protestant nun Marguerite Hebert, is confronted with secular and religious patriarchal hierarchies that displace the key to her individuation, the mastery of her body and sexuality. This paper explores the triangulation set up by an autobiographical mode, the confessional letter, the mastery of female sexuality and its role in the coming to terms with Hebert ’s gendered self. The former acts as the vehicle to tackle the many contradictions inherent in the protagonist life, while it also screens a retrospective autobiography that deploys a controversial approach to Hebert ’s sexual drives. This challenges the ahistorical existence of the typical nun consecrated to its present, reconstructs the nun ’s past and envisions her future. Marguerite ’s writing subverts the Protestant way to perfection and makes room for a lay path to self-recognition. La novela de Marian Engel The Glassy Sea (1978) presenta a una mujer en busca de voz creativa y legitimadora de su experiencia personal a través de un proceso complejo de individuación. La aceptación de sí misma es doblemente complicada, ya que su protagonista, la monja protestante Marguerite Hebert ha de enfrentarse a las jerarquías patriarcales religiosas y seculares que desplazan la clave de su individuación, el dominio de su cuerpo y sexualidad. Este artículo explora la triangulación generada por un modo autobiográfico, la carta confesional, el dominio de la sexualidad femenina y su papel en la creación del sujeto genérico de Hebert. La primera actúa como el vehículo para acotar las muchas contradicciones inherentes a la vida de la protagonista, mientras que proporciona una autobiografía retrospectiva que despliega un controvertido enfoque del impulso sexual de Hebert. Éste desafía la existencia ahistórica de la monja típica consagrada a su presente, reconstruye su pasado y proporciona una visión de su futuro. Los escritos de Marguerite subvierten el énfasis protestante de perfección mientras que abren una senda laica de conocimiento propio

1D Cellular Automata for Pulse Width Modulated Compressive Sampling CMOS Image Sensors

Compressive sensing (CS) is an alternative to the Shannon limit when the signal to be acquired is known to be sparse or compressible in some domain. Since compressed samples are non-hierarchical packages of information, this acquisition technique can be employed to overcome channel losses and restricted data rates. The quality of the compressed samples that a sensor can deliver is affected by the measurement matrix used to collect them. Measurement matrices usually employed in CS image sensors are recursive random-like binary matrices obtained using pseudo-random number generators (PRNG). In this paper we analyse the performance of these PRNGs in order to understand how their non-idealities affect the quality of the compressed samples. We present the architecture of a CMOS image sensor that uses class-III elementary cellular automata (ECA) and pixel pulse width modulation (PWM) to generate onchip a measurement matrix and high the quality compressed samples.Ministerio de Economía y Competitividad TEC2015-66878-C3-1-RJunta de Andalucía TIC 2338-2013Office of Naval Research N000141410355CONACYT (Mexico) MZO-2017-29106

A CMOS 0.18μm 64×64 single photon image sensor with in-pixel 11b time-to-digital converter

The design and characterization of a CMOS 64×64 single-photon avalanche-diode (SPAD) array with in-pixel 11b time-to-digital converter (TDC) is presented. It is targeted for time-resolved imaging, in particular 3D imaging. The achieved pixel pitch is 64μm with a fill factor of 3.5%. The chip was fabricated in a 0.18μm standard CMOS technology and implements a double functionality: Time-of-Flight estimation and photon counting. The imager features a programmable time resolution for the array of TDCs from 625ps down to 145ps. The measured accuracy of the minimum time bin is lower than ±1LSB DNL and 1.7LSB INL. The TDC jitter over the full dynamic range is less than 1LSB. Die-to-die process variation and temperature are discarded by auto-calibration. Fast quenching/restore circuit on each pixel lowers the power consumption by limiting the avalanche currents. Time gatedoperation is possible as well.Office of Naval Research (USA) N000141410355Ministerio de Economía y Competitividad TEC2012-38921- C02, IPT- 2011-1625-430000, IPC- 20111009 CDTIJunta de Andalucía TIC 2012- 233

A CMOS 8×8 SPAD array for Time-of-Flight measurement and light-spot statistics

The design and simulation of a CMOS 8 × 8 single photon avalanche diode (SPAD) array is presented. The chip has been fabricated in a 0.18μm standard CMOS technology and implements a double functionality: measuring the Time-of-Flight with the help of a pulsed light source; or computing focal-plane statistics in biomedical imaging applications based on a concentrated light-spot. The incorporation of on-chip processing simplifies the interfacing of the array with the host system. The pixel pitch is 32μm, while the diameter of the quasi-circular active area of the SPADs is 12μm. The 113μm 2 active area is surrounded by a T-well guard ring. The resulting breakdown voltage is 10V with a maximum excess voltage of 1.8V. The pixel incorporates a novel active quenching/reset circuit. The array has been designed to operate with a laser pulsed at 20Mhz. The overall time resolution is 115ps. Focal-plane statistics are obtained in digital format. The maximum throughput of the digital output buffers is 200Mbps.Ministerio de Economía y Competitividad IPT-2011-1625- 430000, IPC-20111009Office of Naval Research (USA) N00014111031