7,247 research outputs found

    Frequency stabilization of an external-cavity diode laser

    Get PDF
    Using a hybrid optical/electronic technique, an external-cavity diode laser was frequency stabilized with respect to the sub-Doppler spectrum of cesium vapor. Laser linewidths of 65 kHz and frequency stabilities of ±10 kHz were obtained

    C60 adsorption on an aperiodically modulated Cu surface

    Get PDF
    Copper deposited on the ve-fold surface of icosahedral Al-Pd-Mn forms domains of a structure whose surface has a one-dimensional aperiodic modulation. It is shown that C60 deposited on this aperiodic film has highly reduced mobility as compared to C60 deposited on periodic Cu surfaces. This fnding is explained in terms of the recently proposed structural model of this system

    Shot Noise Suppression in Avalanche Photodiodes

    Full text link
    We identify a new shot noise suppression mechanism in a thin (~100 nm) heterostructure avalanche photodiode. In the low-gain regime the shot noise is suppressed due to temporal correlations within amplified current pulses. We demonstrate in a Monte Carlo simulation that the effective excess noise factors can be <1, and reconcile the apparent conflict between theory and experiments. This shot noise suppression mechanism is independent of known mechanisms such as Coulomb interaction, or reflection at heterojunction interfaces.Comment: Phys. Rev. Lett., accepted for publicatio

    Discreteness without symmetry breaking: a theorem

    Get PDF
    This paper concerns sprinklings into Minkowski space (Poisson processes). It proves that there exists no equivariant measurable map from sprinklings to spacetime directions (even locally). Therefore, if a discrete structure is associated to a sprinkling in an intrinsic manner, then the structure will not pick out a preferred frame, locally or globally. This implies that the discreteness of a sprinkled causal set will not give rise to ``Lorentz breaking'' effects like modified dispersion relations. Another consequence is that there is no way to associate a finite-valency graph to a sprinkling consistently with Lorentz invariance.Comment: 7 pages, laTe

    Discreteness and the transmission of light from distant sources

    Get PDF
    We model the classical transmission of a massless scalar field from a source to a detector on a background causal set. The predictions do not differ significantly from those of the continuum. Thus, introducing an intrinsic inexactitude to lengths and durations - or more specifically, replacing the Lorentzian manifold with an underlying discrete structure - need not disrupt the usual dynamics of propagation.Comment: 16 pages, 1 figure. Version 2: reference adde

    Pengaruh Kapasitas Sumber Daya Manusia, Pemanfaatan Teknologi Informasi, Pengendalian Intern Akuntansi, dan Komitmen Organisasi terhadap Keterandalan Pelaporan Keuangan Pemerintah Daerah (Survei pada Skpd Se-kabupaten Kuansing)

    Full text link
    This research aims to examine the effect of , Human resource capacity, Information technology utilization, Accounting intern control and comitmen organisation. This research is motivated by the fact that the government financial reporting should provide information on reliable and timely in assessing accountability and decision making of various parties. All variables in this research were measured using a likert scale.The data in this study is the primary data obtained from questionnaires distributed directly to the respondents. Data collected from 54 respondents who are working at financial reporting staff in SKPD of Kuansing regency. The method of data analysis used to test the hypothesis is multiple regression analysis using the program SPSS 20 version.The results of this study is showed that capacity of human resources, utilization of technology, internal accounting controls, and comitmen organisation influence to the reliability of financial reporting in Kuansing regency.Keywords: The reliability of financial reporting, Human resource capacity, Information technology utilization, Internal control system and comitmen organisatio

    A comparison of the recording of comorbidity in primary and secondary care by using the Charlson Index to predict short-term and long-term survival in a routine linked data cohort

    Get PDF
    OBJECTIVE: Hospital admission records provide snapshots of clinical histories for a subset of the population admitted to hospital. In contrast, primary care records provide continuous clinical histories for complete populations, but might lack detail about inpatient stays. Therefore, combining primary and secondary care records should improve the ability of comorbidity scores to predict survival in population-based studies, and provide better adjustment for case-mix differences when assessing mortality outcomes. DESIGN: Cohort study. SETTING: English primary and secondary care 1 January 2005 to 1 January 2010. PARTICIPANTS: All patients 20 years and older registered to a primary care practice contributing to the linked Clinical Practice Research Datalink from England. OUTCOME: The performance of the Charlson index with mortality was compared when derived from either primary or secondary care data or both. This was assessed in relation to short-term and long-term survival, age, consultation rate, and specific acute and chronic diseases. RESULTS: 657,264 people were followed up from 1 January 2005. Although primary care recorded more comorbidity than secondary care, the resulting C statistics for the Charlson index remained similar: 0.86 and 0.87, respectively. Higher consultation rates and restricted age bands reduced the performance of the Charlson index, but the index's excellent performance persisted over longer follow-up; the C statistic was 0.87 over 1 year, and 0.85 over all 5 years of follow-up. The Charlson index derived from secondary care comorbidity had a greater effect than primary care comorbidity in reducing the association of upper gastrointestinal bleeding with mortality. However, they had a similar effect in reducing the association of diabetes with mortality. CONCLUSIONS: These findings support the use of the Charlson index from linked data and show that secondary care comorbidity coding performed at least as well as that derived from primary care in predicting survival
    • …
    corecore