330 research outputs found
Design of a Network Topology Using CISCO NSO Orchestrator
This paper presents the design of a network topology using CISCO NSO orchestrator. The mismatch problem solution between a network service and its monitoring is proposed. Applying the proposed approach, the telemetry efficiency ratio parameter greater than 40 is achieved. All tests are performed in the real experimental conditions using CISCO NSO orchestrator
Compact UWB MIMO Filtennas with Dual Bandnotch, High Isolation and High Diversity
This paper presents a 4x4 MIMO filtenna aimed for use with UWB applications. The MIMO filtenna is simulated, fabricated and measured. Obtained simulation and measurement results agree well with each other and have been presented to validate the accuracy of the proposed structure. Measured passband is 2.96–11.56 GHz, with dual bandnotch at 3.5 GHz (S11 = -1.25 dB) and 6.05 GHz (S11 = -2.4 dB). Measured isolation is more than 20 dB between all individual elements of the MIMO filtenna. The behaviour of current within the filtenna at the bandnotch frequencies has been shown. Elements of the filtenna exhibit bi-directional radiation patterns in the E-plane and omnidirectional patterns in the H-plane. The gain and efficiency have also been presented; with the average values being 5.3 dBi and 90% respectively. The Envelope Correlation Coefficient has been calculated from both simulations and measurements; with the measured values being below 0.001 for the passband
Techno-economic analysis of heat exchangers with parallel helical tube coils
The paper deals with the investment and exploitation costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined. In addition, the costs of electricity needed to drive pumps, as well as the costs of chemical cleaning of the apparatuses with inhibited mineral acids were estimated
Impulse Response with Correlation Study of a Broadband Bended Wearable Monopole Antenna
In this paper, the impulse response of a wide band flexible circular monopole antenna is presented. The antenna is fabricated on liquid crystalline polymer flexible substrate with a compact geometry that makes it suitable for wearable applications under different bending conditions. The antenna is fed by coplanar waveguide transmission line and has a compact total size of 40 × 22 mm2. The presented antenna has a good performance over the operating frequency range for straight and bent configurations. The design principals, simulation and experimental results are presented in this work
Utilizing artificial neural networks for WLAN positioning
Short range wireless technologies such as WLAN, Bluetooth, RFID, ultrasound and IrDA can be used to supply location information in indoor areas in which their coverage is assured. With respect to outdoor techniques, these technologies are more accurate but with smaller covering areas. In this paper, we present the comparison of the existing location techniques in WLAN networks and a novel approach of utilizing artificial neural networks for positioning purposes. In addition to estimating WLAN client's position, neural networks have been employed to estimate the room and type of the room the client resides in. Extensive measurements were conducted to evaluate these approaches and the obtained results indicate performances sufficient for real case use
Piezoelectric anisotropy: Enhanced piezoelectric response along nonpolar directions in perovskite crystals
This paper discusses the mechanisms that can contribute to the enhanced longitudinal piezoelectric effect along nonpolar directions in perovskite crystals, such as BaTiO3, PbTiO3, KNbO3, Pb(Mg1/3Nb2/3)O3-PbTiO3 and Pb(Zn1/2Nb2/3)O3-PbTiO3. Piezoelectric anisotropy is discussed in relation to temperature induced phase transitions, compositional variation in solid solutions with morphotropic phase boundaries, applied electric fields, the domain wall structure and domain wall displacemen
Linearization of multichannel amplifiers with the injection of second harmonics into the amplifier and predistortion circuit
A linearization technique that uses the injection of the fundamental signal second harmonics together with the fundamental signals at the amplifier input has been extended in this paper by introducing the injection the second harmonics into nonlinear microwave amplifier and so-called predistortion circuit. Predistortion circuit produces the third-order intermodulation signals that are injected at the amplifier input together with the second harmonics making the linearization procedure more independent on the phase variation of the second harmonics. In addition, a considerably better improvement is attained for the power of fundamental signals close to 1-dB compression point by applying the linearization technique proposed in this paper in comparison to the linearization with the injection of the second harmonics merely in the nonlinear amplifier
Techno-economic evaluation of residue exhaustion in batch rectification ethanol production plant
This paper presents the techno-economic optimization of batch plant for production of rectified alcohol based on the concentration of ethanol in residue. The aim of the analysis was to determine the extent to which it is economically profitable to exhaust the residual liquid in boiler. The "profit production" criterion is used for calculations
Improvement of third-order intermodulation product of RF and microwave amplifiers by injection
This paper discusses the improvement in the third-order intermodulation product (IM3) performance obtainable from RF and microwave amplifiers by two alternative injection techniques. The first is the addition to the amplifier input of the second harmonics of the input spectrum and the second is the addition to the amplifier input of the difference frequencies between the spectral components of the input signal. Both techniques are considered in theory, by simulation and in practice. Both techniques give useful improvements in two-tone IM3 performance. The second harmonic technique reduced the IM3 level by 43 dB in an amplifier at 835 MHz. The difference-frequency technique gave a reduction of 48 dB in an amplifier at 880 MHz. The difference-frequency technique also gives a greater improvement for complex spectra signal
Recommended from our members
Exploring the gap between policy and action in Disaster Risk Reduction: A case study from India
The transition from a response-based paradigm to an anticipative, prevention-based approach remains a stubborn challenge in Disaster Risk Reduction (DRR). Whilst the United Nations Office for Disaster Risk Reduction (UNDRR) has advocated the latter since the International Decade for Natural Disaster Reduction in the 1990s, many countries have been slow to move from a response-focused approach to a preventative one. International policy guidelines have successfully informed the national DRR policies in various countries; however, their further translation down to the regional and local level is full of complex political challenges, exacerbated in many areas by an increased frequency of disasters. In this paper we explore the case of India, using the example of landslide risk management. Through an analysis of the evolution of landslide risk governance during the last two decades in two hilly regions – Darjeeling in the Himalayas and the Nilgiris in the Western Ghats – we demonstrate that while the national government appears to have made considerable efforts to move in line with the UNDRR approaches, the eventual outcome of these efforts at the regional and local level is largely an incremental improvement on the existing DRR approach and not a paradigm shift in understanding and addressing disaster risk. We argue that overcoming these issues requires attentiveness to a situated understanding of disasters and institutions at the local level, and not treating apparent gaps between policy and action as functional challenges to be overcome with new science from national level
- …