335 research outputs found
An Analysis of How Work-Life Balance Impacts on Employee Performance and Turnover in the Hotel Industry in Uganda
Purpose- The study explored the relationship between organizational work culture, work-life balance and employee turnover in selected hotels in Uganda and was prompted by the increasing employee turnover in hotels. Method- It purposively sampled employees from selected hotels in Kampala. A cross-sectional survey design was used with a sample size of 278 out of the total population of 1000 hotel employees. Findings- Findings indicated that organizational culture and work-life balance significantly predicted 70% employee turnover. The study recommendations were that hotels in Uganda should improve organizational work culture and work-life balance so as to reduce employee turnover. Originality of the research – While previous research has extensively explored work-life balance in corporate settings, there is limited insight into its interaction with organizational culture within small and medium-sized enterprises (SMEs), which this study addresses. This study uniquely combines social identity theory and organizational support theory to examine how organizational culture influences work-life balance perceptions among diverse employee groups. Employing a mixed-methods approach, this study integrates quantitative surveys with in-depth interviews, allowing for a more comprehensive understanding of how organizational culture impacts employee work-life balance. By offering insights into the link between flexible work arrangements and organizational culture, this research provides actionable recommendations for HR managers to improve employee engagement and retention. In the context of increased remote work and shifting workplace expectations post-COVID-19, this study offers fresh insights into how flexible organizational cultures can better support employee work-life balance
In situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory
The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole. It uses 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. An unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. We examine birefringent light propagation through the polycrystalline ice microstructure as a possible explanation for this effect. The predictions of a first-principles model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties include not only the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube light-emitting diode (LED) calibration data, the theory and parameterization of the birefringence effect, the fitting procedures of these parameterizations to experimental data, and the inferred crystal properties.Peer Reviewe
In situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory
The IceCube Neutrino Observatory instruments
about 1 km3 of deep, glacial ice at the geographic South
Pole. It uses 5160 photomultipliers to detect Cherenkov
light emitted by charged relativistic particles. An unexpected
light propagation effect observed by the experiment is an
anisotropic attenuation, which is aligned with the local flow
direction of the ice. We examine birefringent light propaga-
tion through the polycrystalline ice microstructure as a pos-
sible explanation for this effect. The predictions of a first-
principles model developed for this purpose, in particular
curved light trajectories resulting from asymmetric diffusion,
provide a qualitatively good match to the main features of the
data. This in turn allows us to deduce ice crystal properties.
Since the wavelength of the detected light is short compared
to the crystal size, these crystal properties include not only
the crystal orientation fabric, but also the average crystal size
and shape, as a function of depth. By adding small empiri-
cal corrections to this first-principles model, a quantitatively
accurate description of the optical properties of the IceCube
glacial ice is obtained. In this paper, we present the exper-
imental signature of ice optical anisotropy observed in Ice-
Cube light-emitting diode (LED) calibration data, the theory
and parameterization of the birefringence effect, the fitting
procedures of these parameterizations to experimental data,
and the inferred crystal propertie
Searching for IceCube sub-TeV neutrino counterparts to sub-threshold Gravitational Wave events
Since the release of the Gravitational Wave Transient Catalogue GWTC-2.1 by the LIGO-Virgo collaboration, sub-threshold gravitational wave (GW) candidates are publicly available. They are expected to be released in real-time as well, in the upcoming O4 run. Using these GW candidates for multi-messenger studies complement the ongoing efforts to identify neutrino counterparts to GW events. This in turn, allows us to schedule electromagnetic follow-up searches more efficiently. However, the definition and criteria for sub-threshold candidates are pretty flexible. Finding a multi-messenger counterpart via archival studies for these candidates will help to set up strong bounds on the GW parameters which are useful for defining a GW signal as sub-threshold, thereby increasing their significance for scheduling follow-up searches. Here, we present the current status of this ongoing work with the IceCube Neutrino Observatory. We perform a selection of the sub-threshold GW candidates from GWTC-2.1 and conduct an archival search for sub-TeV neutrino counterparts detected by the dense infill array of the IceCube Neutrino Observatory, known as "DeepCore". For this, an Unbinned Maximum Likelihood (UML) method is used. We report the 90% C.L. sensitivities of this sub-TeV neutrino dataset for each selected sub-threshold GW candidate, considering the spatial and temporal correlation between the GW and neutrino events within a 1000 s time window
Design and Performance of the mDOM Mainboard for the IceCube Upgrade
About 400 mDOMs (multi-PMT Digital Optical Modules) will be deployed as part of the IceCube Upgrade Project. The mDOM’s high pressure-resistant glass sphere houses 24 PMTs, 3 cameras, 10 flasher LEDs and various sensors. The mDOM mainboard design was challenging due to the limited available volume and demanding engineering requirements, like the maximum overall power consumption, a minimum trigger threshold of 0.2 photoelectrons (PE), the dynamic range and the linearity requirements.
Another challenge was the FPGA firmware design, dealing with about 35 Gbit/s of continuous ADC data from the digitization of the 24 PMT channels, the control of a high speed dynamic buffer and the discriminator output sampling rate of about 1GSPS. High-speed sampling of each of the discriminator outputs at ~1 GSPS improves the leading-edge time resolution for the PMT waveforms. An MCU (microcontroller unit) coordinates the data taking, the data exchange with the surface and the sensor readout. Both the FPGA firmware and MCU software can be updated remotely.
After discussing the main hardware blocks and the analog frontend (AFE) design, test results will be shown, covering especially the AFE performance. Additionally, the functionality of various sensors and modules will be evaluated
Summary of IceCube tau neutrino searches and flavor composition measurements of the diffuse astrophysical neutrino flux
Search for Cosmic-Ray Events Using Radio Signals and CNNs in Data from the IceTop Enhancement Prototype Station
Cosmic-ray air showers emit radio waves that can be used to measure the properties of cosmic-ray primary particles. The radio detection technique presents several advantages, such as low cost and year-round duty cycle as well as the ability to provide high sensitivity to Xmax and energy estimation with minimal theoretical uncertainties, making it a promising tool for studying cosmic
rays at the highest energies. However, the primary limitation of radio detection is the irreducible background from various sources that obscure the impulsive signals generated by air showers. To address this issue, we investigated the use of Convolutional Neural Networks (CNNs), trained on CoREAS simulations and radio backgrounds measured by a prototype station at the South Pole.
We developed two different CNNs: a Classifier that distinguishes between cosmic ray event radio signals and pure background waveforms, and a Denoiser that mitigates background noise to recover the underlying cosmic-ray signal. After training the networks we apply them to the air-shower data to search for radio events. With two months data, we were able to identify 51 candidate events. The event’s arrival direction reconstructed using CNN denoised radio waveforms is found to bein good agreement with the IceTop reconstruction. Finally, our approach demonstrated improved directional reconstruction compared to traditional methods
An improved mapping of ice layer undulations for the IceCube Neutrino Observatory
A precise understanding of the optical properties of the instrumented Antarctic ice sheet is crucial to the performance of the IceCube Neutrino Observatory, a cubic-kilometer Cherenkov array of 5,160 digital optical modules (DOMs) deployed in the deep ice below the geographic South Pole. We present an update to the description of the ice tilt, which describes the undulation of layers of constant optical properties as a function of depth and transverse position in the detector. To date, tilt modeling has been based solely on stratigraphy measurements performed by a laser dust logger during the deployment of the array. We now show that it can independently be deduced using calibration data from LEDs located in the DOMs. The new fully volumetric tilt model not only confirms the magnitude of the tilt along the direction orthogonal to the ice flow obtained from prior dust logging, but also includes a newly discovered tilt component along the flow
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