25 research outputs found

    The impact of personality and competence of leaders on business success

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    Purpose: This article aims to identify leaders’ personality and competence traits that determine success for Polish small and medium-sized enterprises. Design/Methodology/Approach: Empirical data are selected from an experimental survey conducted by the Statistics Poland from December 2017 to January 2018 as part of the Determinants of Entrepreneurship Developments in the SMEs Sector project. We used 20959 surveys of enterprises in which the leader (an owner or a manager) played a dominant role. To test the dependence of measures of success (selected aspects of changes in enterprises) and assessments of the importance of personality and competence features of leaders, we built appropriate contingency tables and used the Pearson chi-square independence test. We also applied logistic regression and calculated the appropriate odds ratios. Findings: When estimating logistic parameters, we obtained a model with five statistically significant variables: beliefs about the possibility of achieving set goals; high aspirations and constant search for new challenges; passion and commitment; fluency in foreign languages; and knowledge of the company’s market. Practical implications: The results of this research suggest for enterprises a need for pro-development activities in the field of managerial competencies.peer-reviewe

    COVID-19 during pregnancy, delivery and postpartum period based on EBM

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    The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become the reason of theglobal health crisis. Since the first case of diagnosed COVID-19 pneumonia was reported in Wuhan, Hubei Province, China,in December 2019, the infection has spread rapidly to all over the world.The knowledge gained from previous human coronavirus infection outbreaks suggests that pregnant women and theirfoetuses represent a high-risk population during infectious disease epidemics.Moreover, a pregnancy, due to the physiological changes involving immune and cardiopulmonary systems, is a statepredisposing women to respiratory complications of viral infection.The constantly increasing number of publications regarding the course of COVID-19 infection in pregnant women has beenpublished, however, the available data remains limited and many questions remain unanswered. The aim of this reviewwas to summarize the literature data and adjusted to current recommendations regarding pregnancy care, delivery andpostpartum period.An extremely important issue is the need to register all the cases of COVID-19 affected women and the course of thesepregnancies to local, regional, or international registries, which will be helpful to answer many clinical and scientific questionsand to create guidelines ensuring an adequate level of care for women affected by COVID-19 infection during pregnancy,delivery and during postpartum period, as well as their newborns

    GKD: Generalized Knowledge Distillation for Auto-regressive Sequence Models

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    Knowledge distillation is commonly used for compressing neural networks to reduce their inference cost and memory footprint. However, current distillation methods for auto-regressive models, such as generative language models (LMs), suffer from two key issues: (1) distribution mismatch between output sequences during training and the sequences generated by the student during its deployment, and (2) model under-specification, where the student model may not be expressive enough to fit the teacher's distribution. To address these issues, we propose Generalized Knowledge Distillation (GKD). GKD mitigates distribution mismatch by sampling output sequences from the student during training. Furthermore, GKD handles model under-specification by optimizing alternative divergences, such as reverse KL, that focus on generating samples from the student that are likely under the teacher's distribution. We demonstrate that GKD outperforms commonly-used approaches for distilling LLMs on summarization, machine translation, and arithmetic reasoning tasks.Comment: First two authors contributed equall

    Distributed feedback InGaN/GaN laser diodes

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    We have realised InGaN/GaN distributed feedback laser diodes emitting at a single wavelength in the 42X nm wavelength range. Laser diodes based on Gallium Nitride (GaN) are useful devices in a wide range of applications including atomic spectroscopy, data storage and optical communications. To fully exploit some of these application areas there is a need for a GaN laser diode with high spectral purity, e.g. in atomic clocks, where a narrow line width blue laser source can be used to target the atomic cooling transition. Previously, GaN DFB lasers have been realised using buried or surface gratings. Buried gratings require complex overgrowth steps which can introduce epi-defects. Surface gratings designs, can compromise the quality of the p-type contact due to dry etch damage and are prone to increased optical losses in the grating regions. In our approach the grating is etched into the sidewall of the ridge. Advantages include a simpler fabrication route and design freedom over the grating coupling strength.Our intended application for these devices is cooling of the Sr+ ion and for this objective the laser characteristics of SMSR, linewidth, and power are critical. We investigate how these characteristics are affected by adjusting laser design parameters such as grating coupling coefficient and cavity length

    Recent progress in distributed feedback InGaN/GaN laser diodes

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    Laser diodes based on Gallium Nitride (GaN) are useful devices in a wide range of applications including atomic spectroscopy, data storage and optical communications. To fully exploit some of these application areas there is a need for a GaN laser diode with high spectral purity, e.g. in atomic clocks, where a narrow linewidth blue laser source can be used to target the atomic cooling transition. We report on the continuous wave, room temperature operation of a distributed feedback laser diode (DFB-LD) with high-order notched gratings. The design, fabrication and characterization of DFB devices based on the (Al,In) GaN material system is described. A single peak emission at 408.6 nm with an optical power of 20 mW at 225 mA and a side mode suppression ratio (SMSR) of 35 dB was achieved. Additionally, we demonstrate the use of a GaN DFB-LD as a transmitter in visible optical communications system. We also present results from a DFB-LD optimized for laser cooling of Sr+

    GaN-based distributed feedback laser diodes for optical communications

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    Over the past 20 years, research into Gallium Nitride (GaN) has evolved from LED lighting to Laser Diodes (LDs), with applications ranging from quantum to medical and into communications. Previously, off-the-shelf GaN LDs have been reported with a view on free space and underwater communications. However, there are applications where the ability to select a single emitted wavelength is highly desirable, namely in atomic clocks or in filtered free-space communications systems. To accomplish this, Distributed Feedback (DFB) geometries are utilised. Due to the complexity of overgrowth steps for buried gratings in III-Nitride material systems, GaN DFBs have a grating etched into the sidewall to ensure single mode operation, with wavelengths ranging from 405nm to 435nm achieved. The main motivation in developing these devices is for the cooling of strontium ions (Sr+) in atomic clock applications, but their feasibility for optical communications have also been investigated. Data transmission rates exceeding 1 Gbit/s have been observed in unfiltered systems, and work is currently ongoing to examine their viability for filtered communications. Ultimately, transmission through Wavelength Division Multiplexing (WDM) or Orthogonal Frequency Division Multiplexing (OFDM) is desired, to ensure that data is communicated more coherently and efficiently. We present results on the characterisation of GaN DFBs, and demonstrate their capability for use in filtered optical communications systems

    InGaN/GaN Laser Diodes and their Applications

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    Gallium nitride (GaN) laser diodes are becoming popular sources not only for lighting but for applications ranging from communications to quantum. This paper presents the use of a commercial, off-the-shelf laser diode, with an emission wavelength of 450 nm, for visible light communication, both in free space and for underwater scenarios. Data rates up to 15 Gbit/s have been achieved by making use of orthogonal frequency division multiplexing (OFDM). In addition, distributed feedback (DFB) lasers have been realised emitting at a single wavelength which lend themselves towards applications where high spectral purity is crucial such as atomic clocks or filtered free space transmission systems. These devices have the grating structure etched into the sidewall of the ridge and work is ongoing to measure the linewidth of these lasers with the intended application of cooling Sr+ ions

    Applications of Single Frequency Blue Lasers

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    Gallium nitride (GaN) sources are becoming a regular part of today's world and are now key devices for lighting infrastructures, communications systems and quantum applications, amongst others. In particular, many applications have seen the shift from LEDs to laser diodes to make use of higher powers, higher bandwidths and increased transmission distances. Laser communication systems are well established, however there are applications where the ability to select a single emitted wavelength is highly desirable, such as quantum atomic clocks or in filtered communication systems. Distributed feedback (DFB) lasers have been realised emitting at a single wavelength where the grating structure is etched into the sidewall of the ridge. The main motivation in developing these lasers is for the cooling of ions in atomic clocks; however their feasibility for optical communications is also explored. Narrow linewidth lasers are desirable and this paper will explore how this is achieved. Data rates in excess of 1 Gbit/s have also been achieved in a directly modulated, unfiltered system. These devices lend themselves towards wavelength division multiplexing and filtered optical communications systems and this will be analysed further in the work presented here
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