Search

The execution of delay-aware applications can be effectively handled by various computing paradigms, including the fog computing, edge computing, and cloudlets. Cloud computing offers services in a centralized way through a cloud server. On the contrary, the fog computing paradigm offers services in a dispersed manner providing services and computational facilities near the end devices. Due to the distributed provision of resources by the fog paradigm, this architecture is suitable for large-scale implementation of applications. Furthermore, fog computing offers a reduction in delay and network load as compared to cloud architecture. Resource distribution and load balancing are always important tasks in deploying efficient systems. In this research, we have proposed heuristic-based approach that achieves a reduction in network consumption and delays by efficiently utilizing fog resources according to the load generated by the clusters of edge nodes. The proposed algorithm considers the magnitude of data produced at the edge clusters while allocating the fog resources. The results of the evaluations performed on different scales confirm the efficacy of the proposed approach in achieving optimal performance. [ABSTRACT FROM AUTHOR]

Background and Aims Coronary flow capacity (CFC) is associated with an observed 10-year survival probability for individual patients before and after actual revascularization for comparison to virtual hypothetical ideal complete revascularization. Methods Stress myocardial perfusion (mL/min/g) and coronary flow reserve (CFR) per pixel were quantified in 6979 coronary artery disease (CAD) subjects using Rb-82 positron emission tomography (PET) for CFC maps of artery-specific size-severity abnormalities expressed as percent left ventricle with prospective follow-up to define survival probability per-decade as fraction of 1.0. Results Severely reduced CFC in 6979 subjects predicted low survival probability that improved by 42% after revascularization compared with no revascularization for comparable severity (P =.0015). For 283 pre-and-post-procedure PET pairs, severely reduced regional CFC-associated survival probability improved heterogeneously after revascularization (P <.001), more so after bypass surgery than percutaneous coronary interventions (P <.001) but normalized in only 5.7%; non-severe baseline CFC or survival probability did not improve compared with severe CFC (P =.00001). Observed CFC-associated survival probability after actual revascularization was lower than virtual ideal hypothetical complete post-revascularization survival probability due to residual CAD or failed revascularization (P <.001) unrelated to gender or microvascular dysfunction. Severely reduced CFC in 2552 post-revascularization subjects associated with low survival probability also improved after repeat revascularization compared with no repeat procedures (P =.025). Conclusions Severely reduced CFC and associated observed survival probability improved after first and repeat revascularization compared with no revascularization for comparable CFC severity. Non-severe CFC showed no benefit. Discordance between observed actual and virtual hypothetical post-revascularization survival probability revealed residual CAD or failed revascularization. [ABSTRACT FROM AUTHOR]

A low-profile electronically reconfigurable WLAN band-notched dual port multiple-input multipleoutput (MIMO) antenna design for ultra-wideband applications has been presented. Antenna elements exhibit good impedance match (S11 ≤ -10 dB) over entire ultrawideband (3.1 to 10.6 GHz) spectrum. The decoupling structure is used to improve isolation (S12/S21) above 20 dB over entire UWB band. Moreover, reconfigurable band-notching is achieved by inserting PIN diodes along the inverted L-shaped slots, in each radiator. Notch at WLAN (5.5 GHz) frequency band is achieved by switching the PIN diode to 'OFF' state. The antenna design is fabricated as well as measured, and the results suggests that the proposed design with switchable WLAN band-notch characteristics is suitable candidate for ultra-wideband applications. [ABSTRACT FROM AUTHOR]

A reconfigurable bandpass filter (BPF) with constant centre frequency and wide tuning range of bandwidth is presented. The proposed filter is based on the novel configuration of two modified asymmetrical $\pi $ -sections with folded shorted stubs loaded on a ring resonator. The novel topology allows the implementation of three reconfigurable passband states. A detailed theoretical analysis for calculating the transmission zeros using ABCD parameters is shown, and the design approach of implementing the random offset–x-, asymmetrical $\pi $ -sections with the folded stubs to get the bandwidth reconfigurability is thoroughly explained. PIN diodes are utilized as switching elements to achieve narrowband/mediumband/wideband response. The measured results indicate an absolute bandwidth tuning range of 1.3 GHz, whereas the −3 dB fractional bandwidth (FBW) can be varied from 37% to 92% while the centre frequency remains constant at 2.4 GHz. The fabricated prototype reconfigurable BPF demonstrates one of the widest 3-dB FBW tuning ranges and one of the highest absolute tuning ranges with a sharp-skirt characteristic. It has also more than 20 dB attenuation in the upper stopband which is extended to 2.7 times the centre frequency. [ABSTRACT FROM AUTHOR]

This brief presents a new coupled-line stepped impedance resonator to design single-/dual-bandpass filters (BPFs). To verify the validity of the design concept a single-band filter with central frequency at 5.2 GHz and a dual-BPF with central frequencies at 3.2 and 5.2 GHz were fabricated and tested. Measured results show low insertion loss (less than 0.8 dB) for the single-band BPF with passband centered at 5.2 GHz with −3 dB fractional bandwidth (FBW) of 9.49% and a dual-band BPF with two passbands centered at 3.2/5.2 GHz with lower and higher passband insertion loss less than 0.6 dB and 0.8 dB respectively, having −3dB FBW of 16.2%/8.2%. The single-band BPF can be used for IEEE802.11a systems, and the dual-band can additionally be used for WiMAX applications. Unwanted spurious frequencies for the two BPFs are cancelled by transmission zeros produced by means of open-ended stubs resulting in extremely wide upper stopband. A thorough derivation is conducted to extract the resonating modes, which are calculated analytically. [ABSTRACT FROM AUTHOR]

A novel dynamically reconfigurable bandpass filter (BPF) employing stepped-impedance resonators (SIRs) that can operate as either a single-band or a dual-band filter is demonstrated. The reconfigurable BPF uses four positive-intrinsic-negative (p-i-n) diodes as switching elements. With the four p-i-n diodes in the “OFF” state, the filter behaves as a low-loss (0.85 dB) single-band BPF with a passband around 2.45 GHz. The reconfigurable SIR filter can operate as a dual-band BPF with two center frequencies at 1.6 and 2.45 GHz. The diodes are dynamically set to the “ON” state in the presence of a 1.6-GHz RF signal that is received by an RF triggered power management unit (PMU), integrated on the back side of the microstrip filter in a dual-layer architecture. The RF triggered PMU consists of a planar inverted-F antenna, a high-efficiency voltage doubler rectifier (47% at −13 dBm) and an active dc-to-dc power booster. The rectified output voltage is used as the enabling voltage for the dc-to-dc power booster. This, in turn, provides the required dc power for the diodes biasing. The filter switches from single-band to dual-band when a wireless input RF signal (> −13 dBm) is received by the RF triggered PMU antenna. [ABSTRACT FROM AUTHOR]

In this letter, a compact, wideband bandpass filter with 31% 3-dB bandwidth, with very sharp roll-off characteristics, low insertion loss of 0.45 dB, high return loss greater than 25 dB, and improved out-of-band performance, suitable for 2.4 GHz WLAN applications is presented. The developed prototype filter is based on a quadruple-mode square ring resonator, connected to two λg/2 short-circuited stubs. In order to improve the out-of-band performance and achieve a wider stopband response, two Γ-shaped band-stop sections are connected on the feeding lines without disturbing the geometric symmetry along the diagonal. Measurements of the fabricated prototype provide experimental verification of the theoretical and simulated behaviour of the proposed filter. [ABSTRACT FROM AUTHOR]

Reversed pulsus paradoxus was first described in 1973 as a rise in peak systolic pressure on inspiration in patients with idiopathic hypertrophic subaortic stenosis or isorhythmic ventricular rhythm and in patients with left ventricular systolic dysfunction on positive pressure ventilation. Positive pressure ventilation, for example, may impel blood from the pulmonary capillaries and venules into the left atrium. This may increase left ventricular preload and accelerate ventricular emptying, which in turn may cause the systolic arterial pressure to rise during inspiration. We observed this phenomenon in a patient with a large pericardial effusion, right ventricular failure, and pulmonary arterial hypertension, and we noted the lack of echocardiographic features of tamponade in the presence of right ventricular hypertrophy and pulmonary hypertension. This case report discusses the subsequent occurrence of acute congestive heart failure after pericardiocentesis. [ABSTRACT FROM AUTHOR]

A novel ring resonator bandpass filter with reconfigurable bandwidth with central frequency at 2.4 GHz is demonstrated. Theoretical analysis for computing the resonant frequencies is shown, and the design approach of implementing $\pi $ -section stubs connected to the ring to obtain the bandwidth reconfigurability is explained. The use of reconfigurable \pi $ -section allows the alteration of the stub’s effective width and therefore the filter’s bandwidth reconfigurability. p-i-n diodes are used as switching elements to achieve the narrowband/wideband response. Coupled line sections are used for suppressing the higher modes by generating out-of-band transmission zeros, resulting in a significantly enhanced out-of-band rejection. Measurements indicate that the 3-dB fractional bandwidth can be switched from 58.5% to 75% at a fixed center frequency of 2.4 GHz with an insertion loss better than 1.1 dB. Moreover, the −20-dB stopband performance is extended to 2.7f_{0} . [ABSTRACT FROM PUBLISHER]