73 research outputs found

    Ultra-dense III-V-on-silicon nitride frequency comb laser

    Get PDF
    A heterogeneously integrated III-V-on-silicon nitride mode-locked laser is demonstrated. The device is fabricated by microtransfer printing an InP/InAlGaAs-based multiple-quantum-well coupon. A dense comb with a 755 MHz repetition rate, a 1 Hz ASE limited RF linewidth and a 200 kHz optical linewidth is achieved

    The effect of wind turbines alongside motorways on drivers’ behaviour

    Get PDF
    This paper presents the results of a first study aimed at investigating whether the presence of wind turbines in close proximity to motorways leads to behavioural adaptations among passing drivers. Empirical data from loop detectors and temporary video cameras were analysed in a study employing a before-and-after design at a site near Rotterdam, The Netherlands. Analyses of driving speed and standard deviation of speed (corrected for trend effects through the use of control sites) were performed as well as analyses of the lateral position and standard deviation of the lateral position and an observation of serious traffic conflicts. The results showed that constructing wind turbines alongside a motorway led to some clearly observable effects on drivers’ behaviour. The analyses of the speed data showed that the mean speed was lowered by 2.24km/h (corrected for trend effects) after the construction of the wind turbines while the standard deviation of the speed significantly increased. After the construction of the wind turbines, drivers took a lateral position somewhat more to the left-hand side in their driving lane. There was an indication close to the 0.05 significance level (p=0.057) that the standard deviation of the lateral position slightly increased when the rotor blades were in transversal position. In the before period as well as in the after period, no serious traffic conflicts were registered. The increase in standard deviation of speed and in lateral position are two factors that intrinsically can have an unfavourable effect on road safety. However, the observed order of magnitude of the change was shown to be quite limited. Earlier research suggests that negative effects on road safety are only expected for changes substantially greater than the ones that were observed in this study. On the other hand, there was a significant reduction in driving speed, which might have a favourable effect on the expected number and severity of crashes, although it could also be a compensatory mechanism that indirectly indicates a reduced driving performance. From these findings, it can be concluded that, based on the observed variables, no substantial negative effects for road safety were found in the present study. The authors recommend continuous monitoring and further research on the topic

    The Ghent Psychotherapy Study (GPS) on the differential efficacy of supportive-expressive and cognitive behavioral interventions in dependent and self-critical depressive patients : study protocol for a randomized controlled trial

    Get PDF
    Background: Major depressive disorder is a leading cause of disease burden worldwide, indicating the importance of effective therapies. Outcome studies have shown overall efficacy of different types of psychotherapy across groups, yet large variability within groups. Although patient characteristics are considered crucial in understanding outcome, they have received limited research attention. This trial aims at investigating the interaction between therapeutic approach (pre-structured versus explorative) and the personality style of patients (dependent versus self-critical), which is considered a core underlying dimension of depressive pathology. Methods/design: This study is a pragmatic stratified (dependent and self-critical patients) parallel trial with equal randomization (allocation 1: 1) conducted in Flanders, Belgium. One hundred and four patients will be recruited and randomized to either 16-20 sessions of cognitive behavioral therapy for depression (pre-structured approach) or 16-20 sessions of short-term psychodynamic psychotherapy for depression (explorative approach) conducted by trained psychotherapists in private practices. The primary outcome is the severity of depression as measured by the Hamilton Rating Scale for Depression at completion of therapy. Secondary outcome measures include self-reported depressive and other symptoms, interpersonal functioning, idiosyncratic complaints, and the presence of the diagnosis of depression. Additional measures include biological measures, narrative material (sessions, interviews), and health care costs. Discussion: This trial presents the test of an often-described, yet hardly investigated interaction between important personality dimensions and therapeutic approach in the treatment of depression. Results could inform therapists on how to match psychotherapeutic treatments to specific personality characteristics of their patients

    Mobile app-based symptom-rhythm correlation assessment in patients with persistent atrial fibrillation

    Get PDF
    Background: The assessment of symptom-rhythm correlation (SRC) in patients with persistent atrial fibrillation (AF) is challenging. Therefore, we performed a novel mobile app-based approach to assess SRC in persistent AF.Methods: Consecutive persistent AF patients planned for electrical cardioversion (ECV) used a mobile app to record a 60-s photoplethysmogram (PPG) and report symptoms once daily and in case of symptoms for four weeks prior and three weeks after ECV. Within each patient, SRC was quantified by the SRC-index defined as the sum of symptomatic AF recordings and asymptomatic non-AF recordings divided by the sum of all recordings.Results: Of 88 patients (33% women, age 68 +/- 9 years) included, 78% reported any symptoms during recordings. The overall SRC-index was 0.61 (0.44-0.79). The study population was divided into SRC-index tertiles: low (= 0.73). Patients within the low (vs high) SRC-index tertile had more often heart failure and diabetes mellitus (both 24.1% vs 6.9%). Extrasystoles occurred in 19% of all symptomatic non-AF PPG recordings. Within each patient, PPG recordings with the highest (vs lowest) tertile of pulse rates conferred an increased risk for symptomatic AF recordings (odds ratio [OR] 1.26, 95% coincidence interval [CI] 1.04-1.52) and symptomatic non-AF recordings (OR 2.93, 95% CI 2.16-3.97). Pulse variability was not associated with reported symptoms.Conclusions: In patients with persistent AF, SRC is relatively low. Pulse rate is the main determinant of reported symptoms. Further studies are required to verify whether integrating mobile app-based SRC assessment in current workflows can improve AF management

    Micro-transfer-printing for III-V/Si PICs

    Get PDF
    Micro-transfer-printing (µTP) enables the intimate integration of a variety of III-V opto-electronic components on silicon photonic integrated circuits (Si PICs). It allows for the scalable manufacturing of complex III-V/Si PICs at low cost

    Modelling the perception of light sources

    No full text
    Colour Appearance Models (CAM) attempt to predict the colour appearance of a stimulus by taking the physical properties of the stimulus and its surroundings into account. The fundamental goal is to look for correlates between the measured optical spectral data of a stimulus and its surrounding and the corresponding perceptual attributes. There are three absolute colour attributes (Brightness, Colourfulness and Hue) and three relative colour attributes (Lightness, Chroma and Saturation). Most of the existing CAMs are developed to describe the perception of related surface colours which implicitly assume the presence of a light source illuminating the target and one or more other surfaces. One of them, CIECAM02 is recommended by the "Commission Internationale d'Eclairage" (CIE). Recently, a new CAM (CAM15u) was developed for unrelated light sources (i.e. self-luminous stimuli seen in a completely dark environment). However, at this moment, there is no colour appearance model for light sources seen in a specific luminous context (e.g. a traffic signal at daytime). A first crucial step is to gather relevant optical data (spectral radiances) and the corresponding perceptual data of the colour attributes of observers. With this new data a new and comprehensive colour appearance model will be developed for these self-luminous stimuli seen in relation to a self-luminous background using the spectral optical data of the stimulus and the background as basic input, and taking into account as much as possible input from the physiologic and neurologic processes of the visual system. This new model can immediately be used when investigating the brightness perception of LED-signalisation.status: publishe

    Exploring the applicability of the CAM18sl brightness prediction

    No full text
    Recently, a color appearance model, CAM18sl, has been published. The model can predict the color perception (hue, colorfulness, brightness) of self-luminous stimuli seen against neutral backgrounds varying in luminance. In this paper, the applicability of CAM18sl to situations different from the one for which it was originally developed is explored. The brightness perception predicted by this model (expressed in "bright") is compared with the outcome of the CIE Unified Glare Rating (UGR) for luminaires, the limiting luminance values for Variable Message Signs as indicated in the European standard for outdoor situations, the visual gloss (VG) formula to characterize the gloss of objects, the CIE grey-scale calculation for self-luminous devices, and the predicted brightness value of illuminated objects according to CIECAM02. Although the application domains mentioned above are very distinct, it appears that the predicted brightness perception of the CAM18sl model correlates well with the outcome of the particular and dedicated metrics. It seems that, for brightness perception, CAM18sl can be considered as a general model applicable for a wide range of applications. This could lead to a reduction of a number of application-specific metrics.status: publishe

    The influence of the background luminance on the brightness perception of self-luminous stimuli

    No full text
    status: publishe

    Brightness perception of related self-luminous stimuli

    No full text
    status: publishe

    The secret lives of artworks : exploring the boundaries between art and work

    No full text
    The Secret Lives of Art Works is a collection of essays on the phenomenon that viewers treat works of art as living beings: they attribute life, personhood and agency to them, kiss them, beat them, or claim that portraits look at viewers, and that statues move, breathe and speak. This volume engages in existent theories of these phenomena in art history, psychology, aesthetics and anthropology developed by the members of the Leiden ‘Art, Agency and Living Presence’ group. The Secret Lives of Art Works identifies new areas of research and presents the theoretical and historical account exploring the boundaries between ‘Art and Life’.9789400600577 (ebook)Wetensch. publicati
    • …
    corecore