72 research outputs found

    Predicting Tetris Performance Using Early Keystrokes

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    In this study, we predict the different levels of performance in a Nintendo Entertainment System (NES) Tetris session based on the score and the number of matches played by the players. Using the first 45 seconds of gameplay, a Random Forest Classifier was trained on the five keys used in the game obtaining a ROC_AUC score of 0.80. Further analysis revealed that the number of down keys (forced drop) and the number of left keys (left translation) are the most relevant keys in this task, showing that by merely including the data from these two keys our Random Forest Classifier reached a ROC_AUC score of 0.83.We conclude that the keylogger data during the early phases of a game session can be successfully used to predict performance in longer sessions of Tetris

    Tracking Early Differences in Tetris Perfomance Using Eye Aspect Ratio Extracted Blinks

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    This study aimed to evaluate if eye blinks can be used to discriminate players with different performance in a session of Nintendo Entertainment System (NES) Tetris. To that end, we developed a state-of-the-art method for blink extraction from EAR measures, which is robust enough to be used with data collected by a low-grade webcam such as the ones widely available on laptop computers. Our results show a significant decrease in blink rate per minute (blinks/m) during the first minute of playing Tetris. After having defined 3 groups of proficiency based on in-game performance (Novices, Intermediates, and Experts) we found out that expert players display a significantly lower decrease in blinks/m compared to novices during the first minute of gameplay, which shows that Tetris players' proficiency can be detected by looking at eye blinks/m variations during the early phase of a game session. This difference in blinks/m is observed throughout the entire game session, which supports the general conclusion that proficient Tetris players have a lower decrease in blinks/m, even when playing more difficult levels. Finally, we offer some interpretations of this effect and the relationship that our results may have with the visual cognitive workload experienced during the gameplay

    Introducing “The Sustainable Port”: A Serious Game to Study Decision-Making in Port-Related Environments

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    In this paper, we report on the development of The Sustainable Port video game, which aims to simulate the complex dynamics and decisions occurring in the present and future development of a port area considering environmental aspects (CO2 emissions) and profit. To evaluate if this game fulfills its purpose, we asked 75 students and 34 employees at the Port of Rotterdam (PoR) to play The Sustainable Port. Our results show that PoR employees score higher than students suggesting a transfer between real-life experience of being an employee in the port and performance in the game. Furthermore, port participants reported that The Sustainable Port can be successfully used to start discussions about the future of the Port of Rotterdam and to raise awareness about the complexity characterizing the decision-making processes occurring in a port environment. Our results, taken together, provide evidence of the effectiveness of The Sustainable Port in simulating dynamics occurring in port development and give us optimism about future applications

    Pressure-dependence of arterial stiffness: potential clinical implications

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    Background: Arterial stiffness measures such as pulse wave velocity (PWV) have a known dependence on actual blood pressure, requiring consideration in cardiovascular risk assessment and management. Given the impact of ageing on arterial wall structure, the pressure-dependence of PWV may vary with age. Methods: Using a noninvasive model-based approach, combining carotid artery echo-tracking and tonometry waveforms, we obtained pressure-area curves in 23 hypertensive patients at baseline and after 3 months of antihypertensive treatment. We predicted the follow-up PWV decrease using modelled baseline curves and follow-up pressures. In addition, on the basis of these curves, we estimated PWV values for two age groups (mean ages 41 and 64 years) at predefined hypertensive (160/90 mmHg) and normotensive (120/80mmHg) pressure ranges. Results: Follow-up measurements showed a near 1 m/s decrease in carotid PWV when compared with baseline, which fully agreed with our model-prediction given the roughly 10mmHg decrease in diastolic pressure. The stiffness-blood pressure-age pattern was in close agreement with corresponding data from the 'Reference Values for Arterial Stiffness' study, linking the physical and empirical bases of our findings. Conclusion: Our study demonstrates that the innate pressure-dependence of arterial stiffness may have implications for the clinical use of arterial stiffness measurements, both in risk assessment and in treatment monitoring of individual patients. We propose a number of clinically feasible approaches to account for the blood pressure effect on PWV measurements

    Pressure-Corrected Carotid Stiffness and Young's Modulus: Evaluation in an Outpatient Clinic Setting

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    Background: Conventional measures for assessing arterial stiffness are inherently pressure dependent. Whereas statistical pressure adjustment is feasible in (larger) populations, it is unsuited for the evaluation of an individual patient. Moreover, statistical "correction"for blood pressure may actually correct for: (i) the acute dependence of arterial stiffness on blood pressure at the time of measurement; and/or (ii) the remodeling effect that blood pressure (hypertension) may have on arterial stiffness, but it cannot distinguish between these processes. METHODS: We derived - assuming a single-exponential pressure-diameter relationship - 3 theoretically pressure-independent carotid stiffness measures suited for individual patient evaluation: (i) stiffness index β0, (ii) pressure-corrected carotid pulse wave velocity (cPWVcorr), and (iii) pressure-corrected Young's modulus (Ecorr). Using linear regression analysis, we evaluated in a sample of the CATOD study cohort changes in mean arterial pressure (ΔMAP) and comparatively the changes in the novel (Δβ0, ΔcPWVcorr, and ΔEcorr) as well as conventional (ΔcPWV and ΔE) stiffness measures after a 2.9 ± 1.0-year follow-up. RESULTS: We found no association between ΔMAP and Δβ0, ΔcPWVcorr, or ΔEcorr. In contrast, we did find a significant association between ΔMAP and conventional measures ΔcPWV and ΔE. Additional adjustments for biomechanical confounders and traditional risk factors did neither materially change these associations nor the lack thereof. Conclusions: Our newly proposed pressure-independent carotid stiffness measures avoid the need for statistical correction. Hence, these measures (β0, cPWVcorr, and Ecorr) can be used in a clinical setting for (i) patient-specific risk assessment and (ii) investigation of potential remodeling effects of (changes in) blood pressure on intrinsic arterial stiffness

    A High Eccentricity Component in the Double Planet System Around HD 163607 and a Planet Around HD 164509

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    We report the detection of three new exoplanets from Keck Observatory. HD 163607 is a metal-rich G5IV star with two planets. The inner planet has an observed orbital period of 75.29 ±\pm 0.02 days, a semi-amplitude of 51.1 ±\pm 1.4 \ms, an eccentricity of 0.73 ±\pm 0.02 and a derived minimum mass of \msini = 0.77 ±\pm 0.02 \mjup. This is the largest eccentricity of any known planet in a multi-planet system. The argument of periastron passage is 78.7 ±\pm 2.0^{\circ}; consequently, the planet's closest approach to its parent star is very near the line of sight, leading to a relatively high transit probability of 8%. The outer planet has an orbital period of 3.60 ±\pm 0.02 years, an orbital eccentricity of 0.12 ±\pm 0.06 and a semi-amplitude of 40.4 ±\pm 1.3 \ms. The minimum mass is \msini = 2.29 ±\pm 0.16 \mjup. HD 164509 is a metal-rich G5V star with a planet in an orbital period of 282.4 ±\pm 3.8 days and an eccentricity of 0.26 ±\pm 0.14. The semi-amplitude of 14.2 ±\pm 2.7 \ms\ implies a minimum mass of 0.48 ±\pm 0.09 \mjup. The radial velocities of HD 164509 also exhibit a residual linear trend of -5.1 ±\pm 0.7 \ms\ per year, indicating the presence of an additional longer period companion in the system. Photometric observations demonstrate that HD 163607 and HD 164509 are constant in brightness to sub-millimag levels on their radial velocity periods. This provides strong support for planetary reflex motion as the cause of the radial velocity variations.Comment: 10 pages, 8 figures, accepted to Ap

    Blink To Win: Blink Patterns of Video Game Players Are Connected to Expertise

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    In this study, we analyzed the blinking behavior of players in a video game tournament. Our aim was to test whether spontaneous blink patterns differ across levels of expertise. We used blink rate, blink duration, blink frequency, and eyelid movements represented by the Eye Aspect Ratio (EAR) to train a machine learning classifier to discriminate between different levels of expertise. Classifier performance was highly influenced by features such as the mean, standard deviation and median EAR. Moreover, further analysis suggests that blinking rate and blink duration are likely to increase along with the level of expertise. We speculate this may be indicative of a reduction in cognitive load and lowered stress of expert players. In general, our results suggest that EAR and blink patterns can be used to identify different levels of expertise of video game players

    HARPS3 for a roboticized Isaac Newton telescope

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.We present a description of a new instrument development, HARPS3, planned to be installed on an upgraded and roboticized Isaac Newton Telescope by end-2018. HARPS3 will be a high resolution (R = 115,000) echelle spectrograph with a wavelength range from 380-690 nm. It is being built as part of the Terra Hunting Experiment - a future 10 year radial velocity measurement programme to discover Earth-like exoplanets. The instrument design is based on the successful HARPS spectrograph on the 3.6m ESO telescope and HARPS-N on the TNG telescope. The main changes to the design in HARPS3 will be: a customised fibre adapter at the Cassegrain focus providing a stabilised beam feed and on-sky fibre diameter ~ 1.4 arcsec, the implementation of a new continuous flow cryostat to keep the CCD temperature very stable, detailed characterisation of the HARPS3 CCD to map the effective pixel positions and thus provide an improved accuracy wavelength solution, an optimised integrated polarimeter and the instrument integrated into a robotic operation. The robotic operation will optimise our programme which requires our target stars to be measured on a nightly basis. We present an overview of the entire project, including a description of our anticipated robotic operation.R.H. acknowledges the Science and Technologies Facilities Council (STFC) for his PhD studentship award (2015).J.I.G.H. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the 2013 Ram´on y Cajal program MINECO RYC-2013-14875.J.I.G.H., R.R., and S.S.T. also acknowledge the Spanish ministry project MINECO AYA2014-56359-P.NP and ES are grateful to Knut and Alice Wallenberg Foundation for a generous support of the Swedish contribution to the THE project.AD acknowledges the support from Russian Foundation for Basic Research as part of research grant 15-52-12371
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