910 research outputs found
Tunable Fano effect in parallel-coupled double quantum dot system
With the help of the Green function technique and the equation of motion
approach, the electronic transport through a parallel-coupled double quantum
dot(DQD) is theoretically studied. Owing to the inter-dot coupling, the bonding
and antibonding states of the artificial quantum-dot-molecule may constitute an
appropriate basis set. Based on this picture, the Fano interference in the
conductance spectra of the DQD system is readily explained. The possibility of
manipulating the Fano lineshape in the tunnelling spectra of the DQD system is
explored by tuning the dot-lead coupling, the inter-dot coupling, the magnetic
flux threading the ring connecting dots and leads, and the flux difference
between two sub-rings. It has been found that by making use of various tuning,
the direction of the asymmetric tail of Fano lineshape may be flipped by
external fields, and the continuous conductance spectra may be magnetically
manipulated with lineshape retained. More importantly, by adjusting the
magnetic flux, the function of two molecular states can be exchanged, giving
rise to a swap effect, which might play a role as a qubit in the quantum
computation.Comment: 9 pages, 10 figure
Development of a portable community video surveillance system
In 2016, a crime rate has been evidently increasing particularly in Kuala Lumpur areas, including reports on house break-ins, car thefts, motorcycle thefts and robbery. One way of deterring such cases is by installing CCTV monitoring system in premises such as houses or shops, but this usually requires expensive equipment and installation fees. In this paper a cheaper alternative of a portable community video surveillance system running on Raspberry Pi 3 utilizing OpenCV is presented. The system will detect motion based on image subtraction algorithm and immediately inform users when intruders are detected by sending a live video feed to a Telegram group chat, as well as sound the buzzer alarm on the Raspberry Pi. Additionally, any Telegram group members can request images and recorded videos from the system at any time by sending a get request in Telegram which will be handled by Telegram Bot. This system uses the Pi NoIR camera module as the image acquisition device equipped with a 36 LED infrared illuminator for night vision capability. In addition to the Python language, OpenCV, a computer vision simulation from Intel is also used for image processing tasks. The performance analysis of the completed system is also presented computational complexity while offering improved flexibility. The performance time is also presented, where the whole process is run with a noticeable 3 seconds delay in getting the final output
Coherent spin control by electromagnetic vacuum fluctuations
In coherent control, electromagnetic vacuum fluctuations usually cause
coherence loss through irreversible spontaneous emission. However, since the
dissipation via emission is essentially due to correlation of the fluctuations,
when emission ends in a superposition of multiple final states, correlation
between different pathways may build up if the "which-way" information is not
fully resolved (i.e., the emission spectrum is broader than the transition
energy range). Such correlation can be exploited for spin-flip control in a
-type three-level system, which manifests itself as an all-optical
spin echo in nonlinear optics with two orders of optical fields saved as
compared with stimulated Raman processes. This finding represents a new class
of optical nonlinearity induced by electromagnetic vacuum fluctuations.Comment: 7 pages including 5 figure
Determining exciton bandwidth and film microstructure in polythiophene films using linear absorption spectroscopy
We analyze the linear absorption spectrum of regioregular
poly(3-hexylthiophene) films spun from a variety of solvents to probe directly
the film microstructure and how it depends on processing conditions. We
estimate the exciton bandwidth and the percentage of the film composed of
aggregates quantitatively using a weakly interacting H-aggregate model. This
provides a description of the degree and quality of crystallites within the
film and is in turn correlated with thin-film field-effect transistor
characteristics.Comment: Applied Physics Letters (in press); 9 pages, three figure
Extension of Lorenz Unpredictability
It is found that Lorenz systems can be unidirectionally coupled such that the
chaos expands from the drive system. This is true if the response system is not
chaotic, but admits a global attractor, an equilibrium or a cycle. The
extension of sensitivity and period-doubling cascade are theoretically proved,
and the appearance of cyclic chaos as well as intermittency in interconnected
Lorenz systems are demonstrated. A possible connection of our results with the
global weather unpredictability is provided.Comment: 32 pages, 13 figure
The Use of Molecular Analyses in Voided Urine for the Assessment of Patients with Hematuria
Introduction:Patients presenting with painless hematuria form a large part of the urological patient population. In many cases, especially in younger patients, the cause of hematuria is harmless. Nonetheless, hematuria could be a symptom of malignant disease and hence most patients will be subject to cystoscopy. In this study, we aimed to develop a prediction model based on methylation markers in combination with clinical variables, in order to stratify patients with high risk for bladder cancer.Material and Methods:Patients (n=169) presenting with painless hematuria were included. 54 patients were diagnosed with bladder cancer. In the remaining 115 patients, the cause of hematuria was non-malignant. Urine samples were collected prior to cystoscopy. Urine DNA was analyzed for methylation of OSR1, SIM2, OTX1, MEIS1 and ONECUT2. Methylation percentages were calculated and were combined with clinical variables into a logistic regression model.Results:Logistic regression analysis based on the five methylation markers, age, gender and type of hematuria resulted in an area under the curve (AUC) of 0.88 and an optimism corrected AUC of 0.84 after internal validation by bootstrapping. Using a cut-off value of 0.307 allowed stratification of patients in a low-risk and high-risk group, resulting in a sensitivity of 82% (44/54) and a specificity of 82% (94/115). Most aggressive tumors were found in patients in the high-risk group. The addition of cytology to the prediction model, improved the AUC from 0.88 to 0.89, with a sensitivity and specificity of 85% (39/46) and 87% (80/92), retrospectively.Conclusions:This newly developed prediction model could be a helpful tool in risk stratification of patients presenting with painless hematuria. Accurate risk prediction might result in less extensive examination of low risk patients and thereby, reducing patient burden and costs. Further validation in a large prospective patient cohort is necessary to prove the true clinical value of this model
The effects of nationality differences and work stressors on work adjustment for foreign nurse aides
<p>Abstract</p> <p>Background</p> <p>The main purpose of this study was to discuss the nationality differences of foreign nurse aides and the effect of work stressors influencing work adjustment. And of helping them adapt to Taiwanese society, we summarized the difficulties that foreign nurse aides face in Taiwan.</p> <p>Methods</p> <p>The subjects included 80 foreign nurse aides from the Philippines, Indonesia, and Vietnam who worked in long-term care facilities in Tao Yuan County. We recruited volunteers at the participating facilities to complete the anonymous questionnaires. The return rate of the questionnaire was 88.75%. The validated instruments of Hershenson's (1981) and Schaefer and Moos (1993) were adopted to measure work stressors and work adjustment, respectively. A forward-backward translation process was used in this study.</p> <p>Results</p> <p>Indonesian foreign nurse aides respect their work, and are better workers than Vietnamese and Filipino nurse aids in many respects, which shows how the nationality of the foreign nurse aides might affect work adjustment. The stress created from patient care tasks influenced the foreign nurse aides' personal relationships at work and also affected their attitude when they performed their tasks. In addition, pressure from their supervisors might have affected their work skills, work habits, personal relationships, self-concepts or work attitudes. Moreover, a heavy workload and improper scheduling might have affected the personal relationships and work attitudes of the foreign nurse aides. It was found that work stressors had a significant correlation with work adjustment.</p> <p>Conclusions</p> <p>The results of the present study indicate that training programs are important factors for work adjustment among foreign nurse aides. Furthermore, celebration and leisure activities could be provided to release them from work stressors. More effort should be put into improving the working environment, namely providing a more supportive and enriching atmosphere. Based on these findings, we have a better understanding of how to assist foreign nurse aides in the future.</p
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