Search results for " equipment."
showing 10 items of 314 documents
Increasing the performance of HSDPA with high-speed single frequency network
2012
High Speed Single Frequency Network (HS-SFN) is a multi-cell transmission scheme for High-Speed Downlink Packet Access (HSDPA) that can assist user equipment (UEs) in the softer handover area by combining signals from two neighbouring cells and at the same time by reducing the inter-cell interference. This article analyzes performance of HS-SFN for macro cell scenario under different channels with different type of schedulers by means of extensive system level simulations. The results indicate that HS-SFN can increase throughput for UEs in softer handover area from 40% to 80% without decreasing the overall performance.
Efficient Design of Waveguide Manifold Multiplexers Based on Low-Order EM Distributed Models
2015
In this paper, a new systematic technique to design manifold-coupled multiplexers in waveguide technology is proposed. The new technique uses generalized low-order electromagnetic (EM) distributed models, which constitute a half-way point between the fast, but imprecise, analytical models, and the more accurate, but costly, full-wave EM models. The method can be applied to contiguous and noncontiguous channel multiplexers, in both E-plane or H-plane configurations. This paper covers the complete design procedure for manifold multiplexers, starting from the required specifications and finishing with the physical dimensions. After explaining the general design technique for multiplexers with …
Radiometric Partial Discharge Detection: A Review
2023
One of the most common failures or breakdowns that can occur in high-voltage (HV) equipment is due to partial discharges (PDs). This occurs as a result of inadequate insulation, aging, harsh environmental effects, or manufacturing flaws. PD detection and recognition methods have gained growing attention and have seen great progress in the past decades. Radiometric methods are one of the most investigated detection approaches due to their immunity to electromagnetic interference (EMI) and their capabilities to detect and locate PD activities in different applications such as transformers, cables, etc. Several review articles have been published to classify and categorize these works. Nonethe…
AN INEXPENSIVE ULTRA-HIGH-SPEED PHOTOGRAPHIC TECHNIQUE
1968
Commercial Ultra-High-Speed Cameras for framing rates over 50,000 f.p.s. are very expensive and yield a small number of frames (8 to 24) per run. The single-flash technique with increasing delays gives photographs at a high framing rate over a comparatively long time and, as described here, requires no special electronic equipment except a good flash unit and a general-purpose oscilloscope.
Solitary Vestibular Schwannoma: Decision Making of Treatments
2012
Therapeutic strategies of vestibular schwannomas treatment are changed in the last years. The improvement of surgical equipments and skills allowed increasing the numbers of successful operations in the last 10 years. The results improved in terms of survival, quality of life, recurrences, facial nerve function, and hearing preservation. Also the age of operated patients, once a restriction, becomes progressively a relative limitation to surgical indication. However the progressive widening of MRI availability give to the Otoneurologist the possibility to follow-up the patients with a relative simple radiological examination, delaying the decision to treat surgically the neoplasm only in ca…
To defer or not to defer? A German longitudinal multicentric assessment of clinical practice in urology during the COVID-19 pandemic
2020
PLOS ONE 15(9), e0239027 (2020). doi:10.1371/journal.pone.0239027
Analysis of RRM limitations and restricted transmission periods for VoIP over HSDPA
2009
This paper studies how the performance of Voice over IP (VoIP) over High Speed Downlink Packet Access (HS-DPA) networks is affected if transmission to a User Equipment (UE) is stopped for specific amount of time during handover procedure. This paper also addresses the situation when it might be necessary to limit the number of UEs in a cell. The study showed that parameter settings for Radio Resource Management (RRM) algorithms can have an effect to the VoIP capacity: If handover lasts long enough for VoIP packets to be lost, or severe congestion occurs in a cell, VoIP capacity may be degraded.
Analysis of VoIP over HSDPA Performance with Discontinuous Reception Cycles
2009
The aim of this paper is to evaluate how Discontinuous Reception (DRX) cycles and related timers take effect to Voice over IP (VoIP) performance when High Speed Downlink Packet Access (HSDPA) networks are in question. DRX cycles limit the scheduling freedom of users and increase battery saving opportunities in the User Equipment (UE) by allowing it to turn its receiver circuitry off for some periods of time. Prior work has concentrated mainly on optimizing the usage of radio resources when small bit rate delay critical services, like VoIP, are considered. However, the battery life of small handheld devices might become a limiting factor in providing satisfactory user experience. Thus, this …
The Large Area Detector of LOFT: the Large Observatory for X-ray Timing
2014
LOFT (Large Observatory for X-ray Timing) is one of the five candidates that were considered by ESA as an M3 mission (with launch in 2022-2024) and has been studied during an extensive assessment phase. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. Its pointed instrument is the Large Area Detector (LAD), a 10 m 2 -class instrument operating in the 2-30keV range, which holds the capability to revolutionise studies of variability from X-ray sources on the millisecond time scales. The LAD instrument has now completed the assessment phase but was not down-selected for launch. However, during the assessment, most o…
Muscle Function Differences between Patients with Bulbar and Spinal Onset Amyotrophic Lateral Sclerosis. Does It Depend on Peripheral Glucose?
2021
Background: One of the pathogenic mechanisms of ALS disease is perturbed energy metabolism particularly glucose metabolism. Given the substantial difference in the severity and the prognosis of the disease, depending on whether it has a bulbar or spinal onset, the aim of the study was to determine metabolic differences between both types of ALS, as well as the possible relationship with muscle function. Materials and Methods: A descriptive, analytical, quantitative, and transversal study was carried out in hospitals and Primary Care centers in the region of Valencia, Spain. Fasting glucose and alkaline phosphatase (AP) levels in venous blood, muscle percentage, fat percentage, muscle streng…