10,288 research outputs found
Tour-based Travel Mode Choice Estimation based on Data Mining and Fuzzy Techniques
This paper extends tour-based mode choice model, which mainly includes individual trip level interactions, to include
linked travel modes of consecutive trips of an individual. Travel modes of consecutive trip made by an individual in a
household have strong dependency or co-relation because individuals try to maintain their travel modes or use a few
combinations of modes for current and subsequent trips. Traditionally, tour based mode choice models involved nested
logit models derived from expert knowledge. There are limitations associated with this approach. Logit models assumes
i) specific model structure (linear utility model) in advance; and, ii) it holds across an entire historical observations.
These assumptions about the predefined model may be representative of reality, however these rules or heuristics
for tour based mode choice should ideally be derived from the survey data rather than based on expert knowledge/
judgment. Therefore, in this paper, we propose a novel data-driven methodology to address the issues identified in tour
based mode choice. The proposed methodology is tested using the Household Travel Survey (HTS) data of Sydney
metropolitan area and its performances are compared with the state-of-the-art approaches in this area
Envelope solitons induced by high-order effects of light-plasma interaction
The nonlinear coupling between the light beams and non-resonant ion density
perturbations in a plasma is considered, taking into account the relativistic
particle mass increase and the light beam ponderomotive force. A pair of
equations comprising a nonlinear Schrodinger equation for the light beams and a
driven (by the light beam pressure) ion-acoustic wave response is derived. It
is shown that the stationary solutions of the nonlinear equations can be
represented in the form of a bright and dark/gray soliton for one-dimensional
problem. We have also present a numerical analysis which shows that our bright
soliton solutions are stable exclusively for the values of the parameters
compatible with of our theory.Comment: 9 pages, 5 figure
An unusual cause of respiratory distress
Background: Respiratory distress is a very common presenting complaint in children and neonates, and is one that will regularly face healthcare professionals. A thorough clinical assessment and sound appreciation of the broad range of differential diagnoses is key to enabling effective and subsequent targeted investigation and management of the condition. Bronchogenic cysts, while rare, are one of the most common mediastinal masses encountered in the neonate. The clinical presentation of bronchogenic cysts is variable, however in the neonate they often present with respiratory distress shortly after birth. Radiological appearances are rarely conclusive, with histology required for a definitive diagnosis.
Case: Presented here is a case of a term infant who developed respiratory distress shortly after birth that required intubation and ventilation. Antenatal ultrasound demonstrated a persistent posterior mediastinal cystic structure.
Investigations: Chest radiographs obtained shortly after birth revealed a smooth, well-defined homogenous mediastinal mass, with left lung hyperinflation. Subsequent computed tomography confirmed that the mass was closely related to the trachea anteriorly and oesophagus posteriorly, displacing both of these structures to the right.
Differential diagnosis: Differential diagnosis was of an oesophageal duplication cyst or bronchogenic cyst.
Treatment: After stabilisation on the neonatal intensive care unit, the infant was transferred to a tertiary centre for definitive management. Thoracotomy was performed, and histopathology of the mass confirmed the diagnosis of a bronchogenic cyst.
Outcome and follow up: The infant made an uneventful recovery, and was discharged 17 days post-operatively. She has since been discharged from formal follow up and displays no respiratory complications.
Discussion: This case serves as a reminder to the reader that, although uncommon, bronchogenic cysts should be considered in the differential diagnosis, particularly when assessing the newborn infant with respiratory distress. As such, it provides an important educative value. It also serves to highlight the importance of careful radiographic imaging and interpretation. While often not diagnostic, when used in conjunction with good clinical assessment, imaging can help to narrow the differential diagnosis and subsequently focus the investigation and management
Conditions for the onset of the current filamentation instability in the laboratory
Current Filamentation Instability (CFI) is capable of generating strong
magnetic fields relevant to explain radiation processes in astrophysical
objects and lead to the onset of particle acceleration in collisionless shocks.
Probing such extreme scenarios in the laboratory is still an open challenge. In
this work, we investigate the possibility of using neutral
beams to explore the CFI with realistic parameters, by performing 2D
particle-in-cell simulations. We show that CFI can occur unless the rate at
which the beam expands due to finite beam emittance is larger than the CFI
growth rate and as long as the role of competing electrostatic two-stream
instability (TSI) is negligible. We also show that the longitudinal energy
spread, typical of plasma based accelerated electron-positron fireball beams,
plays a minor role in the growth of CFI in these scenarios
A readiness assessment framework for Blockchain adoption: a healthcare case study
Blockchain technology has been gaining traction across different sectors. It has the potential to immensely benefit the healthcare sector, given the sector's inherent complexities, problems, and inefficiencies. However, to date, no comprehensive, evidence-based effort has been made to understand the readiness of this sector for blockchain adoption. We proposed a readiness assessment framework that encompasses the complex interplay of different underlying factors, social structures, and institutional mechanisms and that covers all key stakeholders. Based on a systematic literature review, the framework is applied to the UAE's healthcare sector and its applicability and usefulness is established. The findings show the multifaceted significance of government readiness in driving blockchain initiatives. Large firms are found to be more willing to leverage the opportunities afforded by blockchain. Lack of clarity on blockchain regulations and laws, and issues pertaining to privacy and trust are found to affect the readiness of all stakeholders. The proposed framework and the study's findings will be useful in guiding policy interventions and developing support mechanisms to strengthen areas related to blockchain adoption
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