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Journal articles on the topic 'Ground-Return Parameters'
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1
E., A. Saafan. "Investigating the Impact of Ground-Return Parameters on Transitional Voltages at Switching-Off Unloaded Power Transmission Lines." Engineering and Technology Journal 9, no. 08 (2024): 4724–34. https://doi.org/10.5281/zenodo.13269398.
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The electrical parameters calculations of the overhead transmission lines are very important to the areas concerned to electromagnetic compatibility and transitional processes in power systems. Therefore, accurate calculations of these parameters were performed in this research, taking into account the ground-return parameters (Carson correction factors). The return parameters of the homogenous ground (one-layered ground) the overhead transmission line passes over were taken into consideration via using the actual value of the ground resistivity. In this research, the effect of ground-return parameters on transitional voltages at switching-off an unloaded transmission line using SF<sub>6</sub> circuit-breaker was recorded and clarified. As a result, when the ground-return parameters are taken into account, the overall transmission line inductance increases. This has an obvious impact on the rate of rise of recovery voltage for the SF<sub>6</sub> circuit-breaker inter-contact space, that consequently affects the transitional voltages during switching-off process.
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Li, Zhen, Jinliang He, Bo Zhang, and Zhanqing Yu. "Influence of frequency characteristics of soil parameters on ground-return transmission line parameters." Electric Power Systems Research 139 (October 2016): 127–32. http://dx.doi.org/10.1016/j.epsr.2015.07.020.
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Machado, M. V. M., J. A. Brandao Faria, and J. F. Borges da Silva. "Ground return effect on wave propagation parameters of overhead power cables." IEEE Transactions on Power Delivery 5, no. 2 (1990): 825–32. http://dx.doi.org/10.1109/61.53089.
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A., I. A. Rahman, A. Bahari M., A. Baharudin Z., A. Zulkefle A., Zainon M., and A. M. Hanafiah M. "Sub Microsecond Analysis of Negative Cloud-to-Ground Lightning Flashes." Indonesian Journal of Electrical Engineering and Computer Science 11, no. 2 (2018): 711–17. https://doi.org/10.11591/ijeecs.v11.i2.pp711-717.
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This paper expounds a software development for the identification of lightning discharged in cloud-to-ground flashes. The study was to reduce a misleading detection of the electric field radiation of lightning discharged profile by considering the important parameters of sub microseconds structure of lightning`s first return stroke. The software built in MATLAB. The software development considered the important parameters of the first return strokes such as peak value, zero crossing, rising time and fast transition time. This study used a modelling technique for training and patterning 19 return strokes from electric radiation field generated by the negative cloud-ground lightning flashes recorded in Universiti Teknikal Malaysia Melaka.19 return strokes data were recorded by using Lecoy HDO4024 with 5 MS/s. The results showed the software recognized the lightning parameters such as peak value, zero crossing, rising time and fast transition time. In conclusion, the software had the potential to decreases the misleading detection of the electric field radiation generated by negative cloud-to-ground lightning flashes.
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Liu, Jiajia, Jianliang Gao, Ming Yang, Dan Wang, and Liang Wang. "Numerical Simulation of Parameters Optimization for Goaf Gas Boreholes." Advances in Civil Engineering 2019 (January 10, 2019): 1–13. http://dx.doi.org/10.1155/2019/3891080.
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In view of the ground drilling of the N2206 working face in Shanxi Wangzhuang Coal Mine, the gas concentration is low and the extraction effect is not good. Fluent computational fluid dynamics software was used to simulate the ground extraction drilling position of the N2206 working face in the goaf (the distance from the top of the coal seam and the distance from the return to the wind). The numerical simulation results show that when the final hole of the ground extraction hole in the goaf is 16 m from the roof of the coal seam and the distance from the return air is 45 m, the extraction effect is optimal. The average extraction gas volume is 9.78 m3/min, and the average extraction gas concentration is 43.95%, the best extraction effect is obtained. After optimizing the ground drilling position in the goaf and combining with the site implementation, the maximum gas scouring amount of the extraction is 12.59 m3/min, which is 3.42 m3/min higher than the original. The maximum gas concentration of extraction was 63.54%, which was 28.82% higher than the original. After optimization, the gas concentration of the extraction is more than 30%, and the extraction effect is very good. Field application results further validate the reliability of theoretical analysis and numerical simulation results.
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Lima, Antonio C. S., Rodolfo A. R. Moura, Marco Aurélio O. Schroeder, and Maria Teresa Correia de Barros. "Assessment of different formulations for the ground return parameters in modeling overhead lines." Electric Power Systems Research 164 (November 2018): 20–30. http://dx.doi.org/10.1016/j.epsr.2018.07.011.
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Garg, Anshuman, and Anjana Goen. "Compact Patch Antenna Parameters Integrating Using Left-Handed Meta Material at 2.41GHz." International Journal of Electrical and Electronics Research 2, no. 3 (2014): 21–24. http://dx.doi.org/10.37391/ijeer.020301.
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This paper propose a new generation of antenna design that applies Meta material properties at the height of 3.2mm above from the ground Plane. Paper also analyzed the performance of Rectangular Micro strip Patch Antenna with and without using the Meta material structure. All antenna parameters such as Return Loss, Gain, Directivity and Band width were measured. The main focus of this paper was to improve Return loss so that Patch antenna used for wide band applications. The additional features were its compact size and used in multiband operation.
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Tselentis, G.-A., and L. Danciu. "Probabilistic seismic hazard assessment in Greece – Part 1: Engineering ground motion parameters." Natural Hazards and Earth System Sciences 10, no. 1 (2010): 25–39. http://dx.doi.org/10.5194/nhess-10-25-2010.
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Abstract. Seismic hazard assessment represents a basic tool for rational planning and designing in seismic prone areas. In the present study, a probabilistic seismic hazard assessment in terms of peak ground acceleration, peak ground velocity, Arias intensity and cumulative absolute velocity computed with a 0.05 g acceleration threshold, has been carried out for Greece. The output of the hazard computation produced probabilistic hazard maps for all the above parameters estimated for a fixed return period of 475 years. From these maps the estimated values are reported for 52 Greek municipalities. Additionally, we have obtained a set of probabilistic maps of engineering significance: a probabilistic macroseismic intensity map, depicting the Modified Mercalli Intensity scale obtained from the estimated peak ground velocity and a probabilistic seismic-landslide map based on a simplified conversion of the estimated Arias intensity and peak ground acceleration into Newmark's displacement.
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Geis-Schroer, Johanna, Sebastian Hubschneider, Lukas Held, et al. "Modeling of German Low Voltage Cables with Ground Return Path." Energies 14, no. 5 (2021): 1265. http://dx.doi.org/10.3390/en14051265.
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In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.
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Dandotiya, Vijay, and Chetan Pathak. "Enhancement in RMPA Parameters by Rhombus Connected With Circle Meta Material Structure Using at 1.9 GHz." International Journal of Electrical and Electronics Research 4, no. 1 (2016): 43–45. http://dx.doi.org/10.37391/ijeer.040110.
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Author proposed a new design of meta-material to provide advancement into the factors of the rectangular microstrip patch antenna (RMPA) “Enhancement in RMPA parameters Rhombus Connected With Circle Meta material structure high using at 1.9GHz” As a rectangular microstrip patch antenna is designed at a height of 1.6mm & Left handed Meta material structure is designed at a height of 3.2mm from the ground plane by using CST-MWS software. The resonance frequency 1.9GHz of the designed antenna is using as a high frequency. This paper mainly worked on return loss. The Return loss of the proposed antenna reduced to -31,16dB & bandwidth is increased up to 41.9MHz. This antenna is small size, cheap, compact and easy to fabricate, and achieve good radiation characteristics with higher return loss. In this paper return loss basically defined as system becomes stable with reduced return loss.
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Koshak, W. J. "Optical Characteristics of OTD Flashes and the Implications for Flash-Type Discrimination." Journal of Atmospheric and Oceanic Technology 27, no. 11 (2010): 1822–38. http://dx.doi.org/10.1175/2010jtecha1405.1.
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Abstract Flashes detected by the Optical Transient Detector (OTD) that occur over the continental United States (CONUS) are intercompared with data from the National Lightning Detection Network (NLDN) in order to partition the OTD flashes into ground and cloud flashes. The entire 5-yr OTD dataset for CONUS is analyzed. The statistical distributions of a variety of optical characteristics are examined, including five flash-level attributes (radiance, area, duration, number of optical groups, and number of optical events), and two group-level attributes [the maximum number of events in a group (MNEG), and a closely related parameter, the maximum group area (MGA)]. On average, there were 5.6 optical groups per return stroke in a ground flash, which is in part due to the likelihood that OTD detects interstroke K changes. It was found that return strokes within ground flashes typically produce large optical groups; hence, the MNEG and MGA parameters serve as useful “return-stroke detectors.” The results of this study provide insight on how to construct an algorithm for retrieving the fraction of ground flashes in a set of flashes observed from a satellite lightning imager. Specifically, even though it is shown that the statistical distributions of the optical characteristics for ground and cloud flashes overlap substantially, the mean values of these distributions differ. Hence, a retrieval method that is based on an analysis of the distribution of the means, and that employs the central limit theorem of statistics, is recommended. As the sample size used to compute the means is increased, the overlap in the distributions of the means for ground and cloud flashes is diminished, making ground flash fraction retrieval feasible. Of the seven optical characteristics examined here, the mean MNEG and mean MGA parameters are suggested as being the most useful for discriminating between ground and cloud flashes in the context of this “central limit theorem” approach.
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Fitsum, Dawit, Dilip Mali, and Mohammed Ismail. "Bandwidth Enhancement of Rectangular Microstrip Patch Antenna using Defected Ground Structure." Indonesian Journal of Electrical Engineering and Computer Science 3, no. 2 (2016): 428. http://dx.doi.org/10.11591/ijeecs.v3.i2.pp428-434.
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<p>This paper presents the bandwidth enhancement of a Proximity Coupled Feed Rectangular Microstrip Patch Antenna using a new Defected Ground Structure - an ‘inverted SHA’ shaped slot on the ground plane of the proximity coupled feed rectangular Microstrip patch antenna. The parameters such as Bandwidth, Return loss, VSWR and Radiation efficiency are improved in the proposed antenna than simple proximity coupled feed rectangular Microstrip patch antenna without Defected Ground Structure. A comparison is also shown for the proposed Microstrip patch antenna with the antenna structure without Defected Ground Structure. The proposed antenna resonates in S-band at frequency of 2.4 GHz with bandwidth of 180 MHz. A very good return loss of -47.9223 dB is obtained for the Microstrip patch antenna with an ’inverted SHA’ shaped Defected Ground Structure. Implementing an ‘inverted SHA’ shaped defect in the ground plane of the proximity coupled feed rectangular Microstrip patch antenna results in 5.3% improvement in bandwidth with 16.01% reduction in the overall area of the ground plane as compared to the Microstrip patch antenna without Defected Ground Structure.</p>
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Setiawan, Muchammad Rofiq Fajar, and Aryo Baskoro Utomo. "The Effect of Parasitic Rings and Ground Plane on Helix Strip Antenna." IJITEE (International Journal of Information Technology and Electrical Engineering) 4, no. 2 (2020): 47. http://dx.doi.org/10.22146/ijitee.55807.
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Strip helix antennas offer better performance at wide bandwidth and more compact in size than conventional helix antennas. However, strip helix antennas have a relatively low gain compared to conventional helix antennas. In this paper, a strip helix antenna with 2.4 GHz frequency was designed, simulated, fabricated, and measured. This strip helix antenna was added with several parasitic rings, and its ground plane size was reduced to increase the gain value and its performance. The best simulation results according to the desired parameters were with return loss < -10 dB of -10.366 dB, VSWR < 2 of 1.8702, and directional radiation pattern of 66.5° beamwidth angle. However, the gain did not match with the desired parameters > 12 dB with the result of 8.9612 dB. Measured results showed that the helix strip antenna has a return loss of -10.37 dB and VSWR of 1.870. The parasitic rings addition can increase the strip helix antenna gain of 0.0201 dB and improves performances of return loss, VSWR, and bandwidth. Despite that, the ground plane size reduction actually decreases the gain value.
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Song, Hao, Hui Zhou, Heng Wang, Yue Ma, Qianyin Zhang, and Song Li. "Retrieval of Tree Height Percentiles over Rugged Mountain Areas via Target Response Waveform of Satellite Lidar." Remote Sensing 16, no. 2 (2024): 425. http://dx.doi.org/10.3390/rs16020425.
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The retrieval of tree height percentiles from satellite lidar waveforms observed over mountainous areas is greatly challenging due to the broadening and overlapping of the ground return and vegetation return. To accurately represent the shape distributions of the vegetation and ground returns, the target response waveform (TRW) is resolved using a Richardson–Lucy deconvolution algorithm with adaptive iteration. Meanwhile, the ground return is identified as the TRW component within a 4.6 m ground signal extent above the end point of the TRW. Based on the cumulative TRW distribution, the height metrics of the energy percentiles of 25%, 50%, 75%, and 95% are determined using their vertical distances relative to the ground elevation in this study. To validate the proposed algorithm, we select the received waveforms of the Global Ecosystem Dynamics Investigation (GEDI) lidar over the Pahvant Mountains of central Utah, USA. The results reveal that the resolved TRWs closely resemble the actual target response waveforms from the coincident airborne lidar data, with the mean values of the coefficient of correlation, total bias, and root-mean-square error (RMSE) taking values of 0.92, 0.0813, and 0.0016, respectively. In addition, the accuracies of the derived height percentiles from the proposed algorithm are greatly improved compared with the conventional Gaussian decomposition method and the slope-adaptive waveform metrics method. The mean bias and RMSE values decrease by the mean values of 1.68 m and 2.32 m and 1.96 m and 2.72 m, respectively. This demonstrates that the proposed algorithm can eliminate the broadening and overlapping of the ground return and vegetation return and presents good potential in the extraction of forest structure parameters over rugged mountainous areas.
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M Lakshmu Naidu, K Amrutha, U Gnaneswari, Ch Sridevi, G Sahasra, and M Kalyan. "Performance analysis of rectangular microstrip patch antenna with partial ground plane." International Journal of Scholarly Research in Engineering and Technology 2, no. 2 (2023): 019–30. http://dx.doi.org/10.56781/ijsret.2023.2.2.0029.
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This paper addresses the design of a rectangular microstrip patch antenna for wireless communication applications at 3.5 GHz resonant frequency. HFSS V13 software was utilized to develop and simulate the antenna. The FR-4 (flame retardant) substrate material, which has a dielectric constant of 4.4 and a thickness of 1.6 mm, was used to design the antenna. The microstrip antenna has a ground dimension of 53.4182mm*34.822mm and a 50Ω impedance. The drawbacks with this microstrip antenna are high VSWR (voltage standing wave ratio) and the return loss is greater than -10db.There are many ways to get over these drawbacks, but one of them is to alter the size of the antenna—specifically, to change the ground plane's size by 37mm*34. 822mm.This paper compares various antenna parameters, including return loss, VSWR, gain, and directivity by switching the ground plane to partial ground plane.
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Burlakoti, Suroj, and Prakash Rai. "Performance Comparison of Swastika and Rectangular Shaped Microstrip Patch Antenna." Kathford Journal of Engineering and Management 1, no. 1 (2018): 11–14. http://dx.doi.org/10.3126/kjem.v1i1.22015.
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In this paper, Microstrip patch antennas with rectangular and swastika shape of patch are designed and its performance parameters are compared with each other. Rectangular and Swastika shaped patch are considered in this paper with common rectangular ground plane. The antenna is simulated at 2.4 GHz using HFSS simulation software. This work mainly includes modification of antenna patch to improve the antenna parameters. The parameters of antenna such as Return loss, VSWR Bandwidth and radiation pattern are compared using simulation. The performance of Swastika shaped antenna was found to be better than rectangular shaped microstrip patch antenna with improved Return Loss, VSWR, Bandwidth and Radiation Pattern.
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Kurtulgu, Zümrüt, and Atınç Pirti. "A new approach for the classification of ground points from airborne LiDAR data in forested areas." Šumarski list 149, no. 1-2 (2025): 45–55. https://doi.org/10.31298/sl.149.1-2.4.
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LiDAR systems are being used increasingly widely and effectively in the field of forestry. They play an important role in many applications such as creating detailed maps of forests, obtaining high-precision elevation data, obtaining information about the height, density and distribution of trees, mapping the topography under the forest in detail, landslide and erosion control, road planning and water management. Underforest topography maps can be created with high precision thanks to LiDAR ground points. In our study, we present a new approach by using LiDAR data to create the physical characteristics of forest land. In this approach, firstly, airborne LiDAR beams were divided into datasets according returns. Three datasets were created: second return, last return and first/last return. Secondly, each dataset was positionally placed in the grid structure. Filtering was done according to mean height values of points in the cell. Thirdly, DBSCAN clustering algorithm, one of the machine learning methods, was used. The epsilon value, one of the parameters used in the DBSCAN algorithm, was determined according to the silhouette index, and LiDAR ground points were classified. The classified LiDAR ground points were compared with the existing ground control points. As a result, the combination of the second return and the last return dataset showed successful results with a kappa value of 82.27% and an F1 score value of 0.71. Also, digital terrain models were created and compared. To demonstrate the effectiveness of the proposed approach, data was compared with the CSF algorithm, which is one of the traditional filtering methods. After the accuracy evaluations, we were able to classify more LiDAR ground points with our proposed approach. Thus, we think that LiDAR ground data can create a detailed and accurate topography map, define forest features and contribute to the decision-making process for forestry activities.
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MARUDDANI, BASO, EFRI SANDI EFRI SANDI, and MUHAMMAD FADHIL NAUFAL SALAM. "Perancangan dan Optimasi Antena Vivaldi pada Sistem Radar Penembus Permukaan (Ground Penetrating Radar)." ELKOMIKA: Jurnal Teknik Energi Elektrik, Teknik Telekomunikasi, & Teknik Elektronika 7, no. 1 (2019): 151. http://dx.doi.org/10.26760/elkomika.v7i1.151.
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ABSTRAKAntena Vivaldi merupakan salah satu jenis antena yang diimplementasikan pada radar penembus permukaan (Ground Penetrating Radar, GPR). GPR adalah salah satu metode non-destructive testing yang biasa digunakan untuk mengetahui kondisi beton/jalan raya. Penelitian ini merancang sebuah antena Vivaldi untuk digunakan pada GPR dengan frekuensi kerja 1 GHz – 2 GHz. Metode yang digunakan untuk merancang dan mengoptimasi antena Vivaldi adalah dengan mengubah beberapa parameter untuk mencapai spesifikasi yang diinginkan. Parameter tersebut antara lain lebar antena, panjang antena dan tapered slot. Optimasi yang dilakukan tetap memperhatikan pola radiasi antena agar tetap terarah. Hasil penelitian ini menghasilkan antena Vivaldi dengan dimensi 350x300 mm dengan return loss di bawah -10 dB pada rentang frekuensi 1 GHz – 2 GHz. Hasil penelitian juga menunjukkan bahwa perubahan nilai parameter lebar antena dan tapered slot menggeser frekuensi kerja antena secara signifikan.Kata kunci: Ground Penetrating Radar, Vivaldi, return loss, parameter antena ABSTRACTThe Vivaldi antenna is one type of antenna that is implemented on Ground Penetrating Radar (GPR). GPR is one of the non-destructive testing methods commonly used to determine the condition of concrete / highway. This studyaim to design a Vivaldi antenna to be used on GPR with a working frequency of 1 GHz - 2 GHz. The method that used to design and optimize Vivaldi antennas is by changing several parameters to achieve the desired specifications. These parameters include antenna width, antenna length and tapered slot. Optimization carried out still observes the radiation pattern of the antenna to keep it directed. The results showed that 350 x 300 mm antennas with return loss below -10 dB in the frequency range of 1 GHz - 2 GHz. The results also show that changes in the parameter width of the antenna and tapered slots shift the antenna working frequency significantly.Keywords: Ground Penetrating Radar, Vivaldi, return loss, antenna parameter
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D'Atnore, M., and M. S. Sarto. "A New Formulation of Flossy Ground Return Parameters for Transient Analysis of Multiconductor Dissipative Lines." IEEE Power Engineering Review 17, no. 1 (1997): 54–55. http://dx.doi.org/10.1109/mper.1997.560697.
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D'Amore, M., and M. S. Sarto. "A new formulation of lossy ground return parameters for transient analysis of multiconductor dissipative lines." IEEE Transactions on Power Delivery 12, no. 1 (1997): 303–14. http://dx.doi.org/10.1109/61.568254.
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Ernst, Michael, Björn Altenburg, and Thomas Schmalz. "Characterizing adaptations of prosthetic feet in the frontal plane." Prosthetics and Orthotics International 44, no. 4 (2020): 225–33. http://dx.doi.org/10.1177/0309364620917838.
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Background: Energy-storage and return feet incorporate various design features including split toes. As a potential improvement, an energy-storage and return foot with a dedicated ankle joint was recently introduced allowing for easily accessible inversion/eversion movement. However, the adaptability of energy-storage and return feet to uneven ground and the effects on biomechanical and clinical parameters have not been investigated in detail. Objectives: To investigate the design-related ability of prosthetic feet to adapt to cross slopes and derive a theoretical model. Study design: Mechanical testing and characterization. Methods: Mechanical adaptation to cross slopes was investigated for six prosthetic feet measured by a motion capture system. A theoretical model linking the measured data with adaptations is proposed. Results: The type and degree of adaptation depends on the foot design, for example, stiffness, split toe or continuous carbon forefoot, and additional ankle joint. The model used shows high correlations with the measured data for all feet. Conclusions: The ability of prosthetic feet to adapt to uneven ground is design-dependent. The split-toe feet adapted better to cross slopes than those with continuous carbon forefeet. Joints enhance this further by allowing for additional inversion and eversion. The influence on biomechanical and clinical parameters should be assessed in future studies. Clinical relevance Knowing foot-specific ability to adapt to uneven ground may help in selecting an appropriate prosthetic foot for persons with a lower limb amputation. Faster and more comprehensive adaptations to uneven ground may lower the need for compensations and therefore increase user safety.
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Gupta, Vivek, and Sandeep Kumar Agrawal. "Enhancement in RMPA Parameters by Meta Material High Frequency Using at 6.65 GHz." International Journal of Electrical and Electronics Research 2, no. 3 (2014): 25–27. http://dx.doi.org/10.37391/ijeer.020302.
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A Rectangular micro strip patch antenna loaded with “Enhancement in RMPA parameters by Rhombus Cut Shaped Meta material high frequency using at 6.65GHz” As a rectangular microstrip patch antenna is designed at a height of 1.6mm & Left handed Meta material structure is designed at a height of 3.2mm from the ground plane by using CST-MWS software. The resonance frequency 6.65GHz of the designed antenna is using as a high frequency. We knew that frequency is increases as a bandwidth is also increases. Therefore in this paper work used at high frequency. The 10 dB impedance bandwidth of proposed antenna is 438.4MHz. The Return loss of the proposed antenna reduced to -34dB. This antenna is small size, cheap, compact and easy to fabricate, and achieve good radiation characteristics with higher return loss.
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Deepthi, Chamkur V., and R. Byrareddy C. "Heptagonal Shaped UWB Antenna with DGS for Wireless LTE with Enhanced Bandwidth." International Journal of Recent Technology and Engineering (IJRTE) 9, no. 3 (2020): 671–177. https://doi.org/10.35940/ijrte.C4491.099320.
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The paper discusses about the implementation of Heptagonal shaped compact ultra-wideband planar Microstrip patch antenna with and without defected ground plane structure (DGS) with analysis of various parameters like return loss, VSWR bandwidth etc. A substrate made up of dielectric constant FR4 epoxy is utilized and the 2D and 3D radiation pattern are also discussed. DGS has helped to fine tune and increase the bandwidth & its effects have been studied. A volume of 28x32x1.7 (1523.2 mm^3) is occupied by the size of antenna with dielectric constant of εr = 4.4, tanδ= 0.02. In order to provide fine tuning in the return loss graph, a 50Ω line with width of W=3mm direct line feeding method has been used for the micro-strip line and slots have been introduced in the ground plane structure, for achieving the good bandwidth coupling between the slots plays an important role. The antenna parameters including VSWR, Gain and return losses v/s frequency effects for the antenna with variation of slots and dimensions has been studied in this paper along with the analysis of important parameters such as return loss (dB), bandwidth, VSWR (Voltage Standing Wave Ratio) of patch antenna which has been performed using Ansoft HFSS v15 tool. The proposed design of the heptagonal shaped antenna operates as an ultra-wide band antenna ranging from 3.20 GHz to 10 GHz and beyond covering most of applications from LTE, Wimax (3.5/5.55GHz), Radio altimeter, RFID and ISM WLAN 5.2/5.8GHz etc.
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Vivek, Singh Kushwah *1. "CIRCULAR DEFECTED GROUND MICROSTRIP BAND-REJECT FILTER DESIGN FOR RADAR COMMUNICATION." International Journal of Engineering Technologies and Management Research 5, no. 2 (SE) (2018): 346–54. https://doi.org/10.5281/zenodo.1247515.
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In this paper, a novel narrow band microstrip band-reject filter is designed using three circular shape defected ground structure (DGS). Three circular shape defected ground structure are linked by a path in the ground plane where etching process is applied. The path length of middle DGS cell is 8 mm and the path length of corner DGS cell is 11 mm whereas the path width of all three DGS cell is 0.6 mm and the radius of circular shape defected ground structure is 2.1 mm. The mid-stop band frequency of the designed filter is 1.61 GHz which is applicable for the satellite and radar communication for the purpose of S-Band. The stop bandwidth of proposed filter is 1 GHz to 2.2 GHz which is useful for narrowband communication. The proposed filter has minimum return loss of 0.11 dB and maximum insertion loss of 60 dB at mid stop-band frequency 1.61 GHz. IE3D 14.1 EM simulation tool is applied for finding out the desired outcome. The proposed microstrip band stop filter has a coverage area of (35.1 mm× 14.4 mm) 505.44 mm2 for the top layer and (16.6 mm× 19 mm) 315.4 mm2 for the ground layer which is more compact as compared to other existing band stop filter designs.
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Shubhi, Jain, K. Khanna R, K. Jain Praveen, Agarwal Ankit, and Rawal Pallav. "Design of EBG Structured Parasitic Patch Antenna for Wireless Communication Applications." European Journal of Advances in Engineering and Technology 5, no. 3 (2018): 207–13. https://doi.org/10.5281/zenodo.10702451.
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<strong>ABSTRACT </strong> In this paper, we have reported the wireless communication application of U shaped antenna with EBG structured ground plane. The proposed antenna was designed on FR4 substrate of 18 x 21 mm<sup>2</sup> dimensions with thickness 1.6 mm. We have systematically designed the antenna starting from U shape patch with partial ground plane. In this structure, very short bandwidth about 2 GHz with resonance frequency at 2.52 GHz was obtained. To improve the parameters of the designed antenna, we have introduced EBG structure (1 x 1 mm<sup>2</sup>) in ground plane. We obtain wide bandwidth of about 7 GHz with resonant frequency 4.10 GHz. Further improvement in antenna parameters was achieved by introducing parasitic elements with different shapes (Hexagonal, Triangle, Rectangle, and Circular). Effect of these parasitic elements on the return loss and radiation pattern over a wide frequency spectrum has been studied. We have applied the parametric analysis on these parasitic elements to optimize the dimensions. For triangle parasitic element, the resonant frequency was observed at 4.11 GHz with band width 6.12 GHz. The return loss i.e. about -62 dB at resonant frequency is also higher as compare to other parasitic structures.
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Deif, Ahmed, Adel M. E. Mohamed, Issa El-Hussain, Yousuf Al-Shijbi, Sherif El-Hady, and Zaid Al Habsi. "Site-specific seismic hazard levels at the economic zone of Duqm, Oman." Journal of Geophysics and Engineering 18, no. 5 (2021): 740–60. http://dx.doi.org/10.1093/jge/gxab050.
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Abstract A site-specific probabilistic seismic hazard assessment (PSHA) was achieved in the area of special economic zone authority of Duqm, involving hazard evaluation at the bedrock conditions and assurance of potential site influence on seismic ground motion at the bedrock. Appropriate source and ground-motion prediction models were selected and seismic hazards were identified by means of 5% damped Uniform Hazard Spectra (UHS) for three return periods of 475, 975, and 2475 years. A logic-tree algorithm was used to study the influence of the epistemic uncertainties on the source models, earthquake recurrency and maximum magnitude, along with ground-motion prediction equations (GMPEs). The local geology effects were characterized by fundamental resonance frequency (Fo) using the horizontal-to-vertical spectral ratio technique and the soil amplification factors. The effects of soil were assessed using SHAKE91 for soil parameters defined by 55 geotechnical boreholes in conjunction with surveys of 2D multichannel analysis of surface waves (MASW) at 90 sites. Scaling was performed for selected strong-motion applying spectral matching technique to be used at the soil column bottom. Selection of such records is based on scenarios characterized by deaggregation of the PSHA results on the bedrock tops. The Duqm area mostly features low amplifications, below 1.3 for the considered spectrum. Surface ground-motion maps show low hazard values with Peak Ground Accelerations (PGA) vary between about 2 and 5% g for a 475-year return period. Although several sites are assessed to be susceptible to liquefy, liquefaction analyses indicate that surface ground motions for a 475-year return period are insufficient to produce liquefaction.
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Oyewole, Olayinka J., Christopher Sirola, Anwaoy Pandit, and Samson Ayo. "The Study of Altitudinal Refractivity and Refractivity Gradient Variations by Weather Parameters in Some Selected Locations in Nigeria." Physical Science International Journal 29, no. 3 (2025): 42–49. https://doi.org/10.9734/psij/2025/v29i3882.
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Weather parameters such as pressure, temperature and humidity significantly affect the altitudinal refractivity and refractivity gradients which in return impact the propagation of the radio wave. The alteration in these parameters changes the atmospheric refractive index. Radio refractivity expresses the degree at which a radio signal bends when it travels through the atmosphere. This study examines weather parameters effects on the altitudinal refractivity and refractivity in some selected locations in Nigeria using existing mathematical models relating them with some meteorological parameters from the ground surface to altitude of 12 Km. Higher Refractivity at the ground surface was observed than at elevated altitudes. Decrease in the weather parameters was continuously noticed up to the tropopause as the altitude was increasing. Refractivity gradient was observed to be greater than -40 N up to a height of 4 Km and less than -40 N above 4 Km. The weather parameters have great influence on the altitudinal refractivity and refractivity in the examined locations.
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Edy Purnomo, M. Fauzan, Dwi Fadila Kurniawan, and M. Rizky Guntur Pratama. "Pengaruh Bending Antena Mikrostrip Star-Patch Terhadap Parameter Antena Dengan Orientasi Bending Sumbu X." ALINIER: Journal of Artificial Intelligence & Applications 4, no. 1 (2023): 1–17. http://dx.doi.org/10.36040/alinier.v4i1.6028.
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Microstrip antennas are used in various dimensions and shapes of microstrip antennas according to needs. In this use it allows bending of the microstrip antenna which changes the characteristics or parameters. In this research a microstrip antenna is designed with 24 star and 12 star patches and a staircase-shaped ground plane working at a frequency of 2.4 GHz. Design and simulation were carried out on the CST Studio Suite 2018 software and measurements were carried out with the ARINTS VNA. The simulation results show that bending causes yield degradation in the microstrip antenna parameters which include Return Loss, VSWR, Gain, Directivity, and Efficiency. the measurement results show that there is degradation in the Return Loss, VSWR, and Gain parameters. the smaller the bending radius that is done so that the antenna bends more, the performance quality value of the antenna parameters decreases.
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Hoole, P. R. P., S. Thirukumaran, Harikrishnan Ramiah, Jeevan Kanesan, and S. R. H. Hoole. "Ground to Cloud Lightning Flash Currents and Electric Fields: Interaction with Aircraft and Production of Ionosphere Sprites." Journal of Computational Engineering 2014 (August 3, 2014): 1–5. http://dx.doi.org/10.1155/2014/869452.
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This paper presents for the first time a case for the importance of ground to cloud (upward leader) lightning flash parameters for safety testing of direct aircraft-lightning interaction and protection of wind turbines, as well as the importance of radiated electric fields for indirect lightning-aircraft interaction and generation of electric discharges called sprites and halos in the ionosphere. By using an electric circuit model of the transverse magnetic waves along the return stroke channel, electric currents at ground level as well as cloud level are determined for both the cloud to ground lightning flash and the ground to cloud lightning flash. We show that when an aircraft triggers lightning, the electric currents will be much more severe in current magnitude, rate of rise of currents, and frequency spectrum than otherwise and are more severe than the parameters observed for the usual and well monitored (and measured) cloud to ground (downward leader) flashes. The rate of rise of currents and the frequency spectrum of the ground to cloud lightning flash are also given here. The electric fields radiated by the lightning flashes that would appear in the ionosphere are presented for both the earth flash and the ground to cloud flash.
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Ningrum, Rohima Wahyu, Wiwit Suryanto, Hendra Fauzi, and Estuning Tyas Wulan Mei. "Mapping of PGA Value Using PSA Method in West Halmahera Nort Maluku." Jurnal Teknosains 9, no. 2 (2020): 116. http://dx.doi.org/10.22146/teknosains.41483.
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The earthquake that occurred in the West Halmahera region was very detrimental, even though the human casualties were not very significant. But it will affect the stability and capacity of a region in terms of regional development. The mapping of earthquake-prone areas is carried out by a probabilistic seismic hazard analysis (PSHA) method to analyze soil movement parameters, namely Peak Ground Acceleration so that it can determine earthquake-prone areas in West Halmahera. The results of seismic hazard analysis show that the West Halmahera area is an area that is relatively prone to earthquake hazards because it is still strongly influenced by subduction (megathrust) earthquakes from the Philippine plate, Maluku sea and Sangihe. This is indicated by the value of earthquake acceleration on the Peak Ground Acceleration for the 500 year return period of around 0.38 - 3.69 g and 0.30 - 3.69 g for the 2500 year return period.
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Garg, Bimal, and Dauood Saleem. "Innovative Double H Metamaterial Structure for Amelioration in Patch Antenna Parameters." Bulletin of Electrical Engineering and Informatics 2, no. 4 (2013): 278–85. http://dx.doi.org/10.11591/eei.v2i4.194.
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A rectangular microstrip patch antenna along with a SSRR based “Double H” shaped metamaterial is proposed and analyzed at a height of 3.2mm from the ground plane. This work is mainly focused on increasing the potential parameters of microstrip patch antennas. The patch antenna along with the proposed metamaterial structure is designed to resonate at 1.84GHz. The impedance bandwidth of the patch antenna along with the proposed metamaterial structure is improved by 12.9MHz and return loss is reduced by 9.89dB. All the simulation work is done by using CST-MWS Software. Double-Negative properties (Negative Permeability and Permittivity) of the proposed metamaterial structure have also been verified using Nicolson-Ross-Weir method (NRW).
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Chawawisuttikool, Jitapa, Chatchai Phirawatthakul, Warintun Thomchaita, Chatchai Tieachanpan, and Orawan Prasartwuth. "Reliability of running parameters using fitness watches synced with accelerometers during outdoor runs." Journal of Associated Medical Sciences 57, no. 1 (2024): 170–76. http://dx.doi.org/10.12982/jams.2024.019.
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Background: To prevent running related injuries and return to sport activities, monitoring the running dynamic parameters (cadence, stride length, ground contact time and vertical oscillation) especially outdoor running is crucial. Previous studies investigated the reliability of these parameters in laboratory settings. However, the nature of outdoor runs is different (curve, uphill, other runners, etc.) and challenging in terms of equipment (simple) and environments (grass, asphalt, rubber, etc.). Therefore, the reliability of these parameters using a fitness watch synced with accelerometer needed to be investigated. Objective: To investigate the reliability of running parameters measured using fitness watches and accelerometers during outdoor runs. Materials and methods: 30 healthy volunteers (age 25.8±9.6 years, height 167.2±9.3 cm, weight 62.4±14.2 kg, and body mass index 22.2±3.8 kg/m2) participated in the study. They wore a fitness watch and attached a synced accelerometer at their pants. They completed 2 running laps (800 meters each) at their comfortable speeds. Resting periods were provided between laps. To control the speed for the second lap, the watch was set the maximum and minimum speed and set vibration and sound alarm mode. Running parameters include cadence, stride length, vertical oscillation, and ground contact time. Results: The reliability of the four running parameters (cadence, stride length, ground contact time, and vertical oscillation), indicated by the intraclass correlation coefficients (ICC (3,k)) was 0.94, 0.97, 0.98 and 0.99, respectively. Very high reliability values were confirmed. Conclusion: Using a fitness watch synced with an accelerometer during outdoor runs, running dynamic parameters (cadence, stride length, ground contact time, and vertical oscillation) illustrated very high levels of reliability.
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Banitsiotou, I. D., T. M. Tsapanos, V. N. Margaris, and P. M. Hatzidimitriou. "Estimation of the seismic hazard parameters for various sites in Greece using a probabilistic approach." Natural Hazards and Earth System Sciences 4, no. 3 (2004): 399–405. http://dx.doi.org/10.5194/nhess-4-399-2004.
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Abstract. The probabilistic approach that was recently introduced by Kijko and Graham (1998,1999) was applied for the estimation of seismic hazard for various sites in Greece in terms of peak ground acceleration (PGA) and peak ground velocity (PGV). These sites represent geographically cities of Greece among which are the capital of Greece and some others with high, intermediate and low seismicity. The approach allows the use of earthquake catalogues with incomplete reported historical and complete instrumental data, the consideration of different magnitude thresholds, and the incorporation of magnitude uncertainties. One of the advantages of the method is that it does not require any determination of seismic zones. The estimated values of PGA for return periods of 476 years were grouped in 4 categories, the same ones used in the seismic hazard map for the New Seismic Code of Greece. Comparison results were quite interesting and very encouraging concerning the reliability of this probabilistic approach.
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Harith, Noor Sheena Herayani, Felix Tongkul, and Azlan Adnan. "Seismic Hazard Curve as Dynamic Parameters in Earthquake Building Design for Sabah, Malaysia." Buildings 13, no. 2 (2023): 318. http://dx.doi.org/10.3390/buildings13020318.
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This paper presents the significance of a seismic hazard curve plot as a dynamic parameter in estimating earthquake-resistant structures. Various cases of structural damages in Malaysia are due to underestimating earthquake loadings since mostly buildings were designed without seismic loads. Sabah is classified as having low to moderate seismic activity due to a few active fault lines. Background point, area, and line sources are the three tectonic features that have impacted Sabah. Data on earthquakes from 1900 to 2021 have been collected by a number of earthquake data centers. The seismicity is based on a list of historical seismicities in the area, which stretches from latitudes 4 °S to 8 °N and longitudes 115 °E to 120 °E. The goal of this research is to develop a seismic hazard curve based on a conventional probabilistic seismic hazard analysis being examined for the maximum peak ground acceleration at 10% probability of exceedance as published in MSEN1998-1:2015. This study extended to 5% and 2% probability of exceedance combined with the seismic hazard curve by using Ranau as a case study. To calculate the expected ground motion recurrence, such as peak ground acceleration at the site, earthquake recurrence models were combined with selected ground motion models. A logic tree structure was used to combine simple quantities such as maximum magnitudes and the chosen ground motion models to describe epistemic uncertainty. The result demonstrates that peak ground acceleration values at the bedrock were estimated to be 0.16, 0.21, and 0.28 g of the total seismic hazard curve at 10%, 5%, and 2% PE in a 50-year return period, respectively. The seismic hazard study at a Ranau site basically depends on the seismicity of a region and the consequences of failure in the past. Thus, the results can be used as a basis for benchmarking design or evaluation decisions and for designing remedial measures for Sabah constructions to minimize structural failure.
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Khinda, Jaspal Singh, Malay Ranjan Tripathy, and Deepak Gambhir. "Multi-Edged Wide-Band Rectangular Microstrip Fractal Antenna Array for C- and X-Band Wireless Applications." Journal of Circuits, Systems and Computers 26, no. 04 (2016): 1750068. http://dx.doi.org/10.1142/s0218126617500682.
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A low-cost multi-edged rectangular microstrip fractal antenna (RMFA) yielding a huge bandwidth of 8.62[Formula: see text]GHz has been proposed in this paper. The proposed fractal antenna design constitutes a radiation patch, fed with 50[Formula: see text][Formula: see text] microstrip line and a partial ground plane. The partial ground plane is the combination of shapes of rectangle and three-point arc. The proposed antenna is simulated as well as fabricated. The simulated results using electromagnetic solver software and measured with vector network analyzer bench MS46322A are presented and compared. The various parameters such as return loss, voltage standing wave ratio (VSWR), antenna impedance, gain, directivity, group delay and phase of [Formula: see text], radiation efficiency and patterns are presented here. The depth of return loss is improved for a wide range of frequencies. The proposed fractal antenna is further extended to linear array to improve the gain and impedance bandwidth. The simulated and measured results prove the superiority of the proposed antenna.
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Damur, D., T. Guerrero, M. Haessig, P. Montavon, and K. Voss. "Force plate gait analysis to assess limb function after tibial tuberosity advancement in dogs with cranial cruciate ligament disease." Veterinary and Comparative Orthopaedics and Traumatology 21, no. 03 (2008): 243–49. http://dx.doi.org/10.1055/s-0037-1617368.
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Summary Objective: To assess functional outcome in dogs with cranial cruciate ligament (CrCL) disease after tibial tuberosity advancement (TTA) using force plate gait analysis, and to evaluate parameters potentially influencing outcome. Study design: Prospective clinical study. Animals: Consecutive clinical patients (n=37) with CrCL-deficient stifles (n=40). Methods: The stifle joints were examined arthroscopically prior to TTA. Meniscal release was not performed if the medial meniscus was intact. Open medial arthrotomy and partial meniscectomy were performed in the presence of meniscal tears. Vertical ground reaction forces were measured preoperatively and at follow-up examinations four to 16 months postoperatively (mean: 5.9 months). The ground reaction forces of a group of 65 healthy dogs were used for the comparison. The potential effects of clinical parameters on functional outcome were evaluated statistically. Results: Complete CrCL rupture was identified in 28 joints, and partial CrCL rupture in 12 joints. The medial meniscus was damaged in 21 stifles. Vertical ground reaction forces were significantly higher at follow-up (P<0.01), but remained significantly lower than those of control dogs (P<0.01). Complications were identified in 25% of joints, and the dogs with complications had significantly lower peak vertical forces at follow-up than the dogs without complications (P=0.04). Other clinical parameters did not influence outcome. Conclusions: Tibial tuberosity advancement significantly improved limb function in dogs with CrCL disease, but did not result in complete return to function. Complications adversely affected functional outcome. Clinical significance: A return to a function of approximately 90% of normal can be expected in dogs with CrCL disease undergoing TTA.
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Gupta, Vivek, and Sandeep Agrawal. "Return loss & Gain Enhancement in RMPA by Rectangle cut Shaped Meta Material Structure Using at 2.097GHz." International Journal of Electrical and Electronics Research 2, no. 3 (2014): 32–35. http://dx.doi.org/10.37391/ijeer.020304.
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In This work, Rectangular Micro strip Patch Antenna (RMPA) along with meta material which has design of “Rectangle Cut Shaped’’ structure is proposed at height of 3.2 mm from the ground plane. The RMPA with proposed Meta material structure is designed to resonate at 2.097 GHz frequency. This work is mainly focused on increasing the potential parameters of micro strip patch antenna. Proposed Meta material structure is significantly reduced the return loss and increased the bandwidth and gain of the antenna with compare to RMPA alone. The gain is increased up to 3.242 in comparison to RMPA alone. The return Loss of proposed antenna is reduced by 41.9db.
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Choudhury, Sachidananda, Veeranki Kalyani, R. Sai Teja, P. Sreenivasan, Sarat K. Kotamraju, and K. Ch. Sri Kavya. "A comparative analysis of rectangular cut edge patch antenna on various substrate." International Journal of Engineering & Technology 7, no. 1.1 (2017): 518. http://dx.doi.org/10.14419/ijet.v7i1.1.10159.
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An analysis of simple microstrip patch antenna has been designed which comprises of various dielectric substrates that is placed in between metallic patch and ground. Substrates used in this design Epoxy (FR4), Rogers duroid 6002 (tm) with various relative permittivity 2.94 and 2.2 and thickness of 3.2mm. Some applications for the designed frequency are wireless fidelity, WLAN application, Bluetooth. The proposed antenna is designed in HFSSV15 Software operating at 2.4 GHz frequency which renders return loss not more than -10dB. The purpose of this paper was analyzation and simulation for the designed antenna with various parameters like gain, peak gain, efficiency, return loss, band-width when the structure and substrate changes.
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Margitová, Anastázia, Michal Kolcun, and Martin Kanálik. "Impact of the Ground on the Series Impedance of Overhead Power Lines." TRANSACTIONS ON ELECTRICAL ENGINEERING 7, no. 3 (2020): 47–54. http://dx.doi.org/10.14311/tee.2018.3.047.
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An overhead power line is a structure used in the electric power system to transmit electrical energy. The performance of overhead power lines depends on their parameters. There are four basic electrical parameters of power lines: resistance, inductance, capacitance, and shut conductance. The paper focuses on the calculation of the series impedance of overhead lines (resistance and inductance) by three different methods (Carsonʹs method, Rüdenbergʹs method and the theory of complex penetration depth) considering the impact of the ground return path. There is also the comparison of these methods and their application on models of real power lines of different voltage levels provided in this paper.
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Montagud, C., J. Corberan, A. Montero, and J. Urchueguía. "Analysis of the energy performance of a ground source heat pump system after five years of operation." Energy and Buildings 43, no. 12 (2011): 3618–26. https://doi.org/10.1016/j.enbuild.2011.09.036.
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GeoCool plant was the result of a EU project whose main purpose was to adapt ground coupled heat pump technology to cooling dominated areas. The execution of this experimental plant was completed at the end of year 2004, starting on February 2005 the regular operation of the air conditioning system. Since then, GeoCool facility has been monitored by a network of sensors characterizing its most relevant parameters. Several aspects of the performance and behaviour of the system during its first operational year were presented on a previous paper. This paper presents the energy performance measurements of GeoCool ground coupled heat pump system acquired during five years of operation as well as the evolution of the return water temperature from the ground as a representative of the ground temperature. The analysis of the experimental results shows that the system energy performance is maintained through the years with no appreciable impact on ground thermal response.
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Arsyad, Ardy, Akhmad Bakri Muhiddin, and Farouk Maricar. "Deterministic and probabilistic Seismic Hazard Assessments for Merangin Kerinci Sumatera." IOP Conference Series: Earth and Environmental Science 1117, no. 1 (2022): 012018. http://dx.doi.org/10.1088/1755-1315/1117/1/012018.
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Abstract This paper presents calculated ground motions for Merangin Kerinci in the Provinsi of Jambi Sumatera. The ground motions were calculated using a probabilistic seismic hazard analysis. The earthquake catalogue used in the analysis included all recorded earthquakes up to the end of July 2019, trimmed for magnitude completeness. Uncertainty in input parameters was considered using a logic tree, with branches including shallow crustal faults of the Great Sumatran Faults and Sumatera Megathrust Subduction. Ground motions are presented for the local site conditions, measured at those sites which can be classified as Site Class D/C (stiff soil to Soft Rock/Very Dense Soil). Ground motions, including Peak Ground Acceleration (PGA), and spectral accelerations at periods ranging from 0.1 s to 10.0s were calculated the site. Data are presented for return periods of 175 years, 475 years, 2,500 years, 5,000 years, and 10,000 years for PSHA, and at mean, 50th, and 84th percentile confidence levels for DSHA. Compared to the Indonesian Seismic Hazard Map (ISHM) 2017 (at DSHA at 5% damping and 84th Percentile), the deterministic PGA values calculated in this study are relatively closed, which is accounted for 0.58g found in this study compared to the range of 0.6g – 0.7 in the ISHM 2017. On the other hand, the probabilistic PGA values for a particular of 5,000 years return period (SEE), the PGA values found in this assessment is 0.73g which is lower than the range of 0.8g – 0.9g in the ISHM 2017.
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Mahmood, Khalid, Naveed Ahmad, Usman Khan, and Qaiser Iqbal. "Seismic hazard maps of Peshawar District for various return periods." Natural Hazards and Earth System Sciences 20, no. 6 (2020): 1639–61. http://dx.doi.org/10.5194/nhess-20-1639-2020.
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Abstract. Probabilistic seismic hazard analysis of Peshawar District has been performed for a grid size of 0.01∘. The seismic sources for the target location are defined as the area polygon with uniform seismicity. The earthquake catalogue was developed based on the earthquake data obtained from different worldwide seismological networks and historical records. The earthquake events obtained at different magnitude scales were converted into moment magnitude using indigenous catalogue-specific regression relationships. The homogenized catalogue was subdivided into shallow crustal and deep-subduction-zone earthquake events. The seismic source parameters were obtained using the bounded Gutenberg–Richter recurrence law. Seismic hazard maps were prepared for peak horizontal acceleration at bedrock level using different ground motion attenuation relationships. The study revealed the selection of an appropriate ground motion prediction equation is crucial for defining the seismic hazard of Peshawar District. The inclusion of deep subduction earthquakes does not add significantly to the seismic hazard for design base ground motions. The seismic hazard map developed for shallow crustal earthquakes, including also the epistemic uncertainty, was in close agreement with the map given in the Building Code of Pakistan Seismic Provisions (2007) for a return period of 475 years on bedrock. The seismic hazard maps for other return periods i.e., 50, 100, 250, 475 and 2500 years, are also presented.
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Işık, Ercan, Aydın Büyüksaraç, Yunus Levent Ekinci, Mehmet Cihan Aydın, and Ehsan Harirchian. "The Effect of Site-Specific Design Spectrum on Earthquake-Building Parameters: A Case Study from the Marmara Region (NW Turkey)." Applied Sciences 10, no. 20 (2020): 7247. http://dx.doi.org/10.3390/app10207247.
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The Marmara Region (NW Turkey) has experienced significant earthquakes (M > 7.0) to date. A destructive earthquake is also expected in the region. To determine the effect of the specific design spectrum, eleven provinces located in the region were chosen according to the Turkey Earthquake Building Code updated in 2019. Additionally, the differences between the previous and updated regulations of the country were investigated. Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV) were obtained for each province by using earthquake ground motion levels with 2%, 10%, 50%, and 68% probability of exceedance in 50-year periods. The PGA values in the region range from 0.16 to 0.7 g for earthquakes with a return period of 475 years. For each province, a sample of a reinforced-concrete building having two different numbers of stories with the same ground and structural characteristics was chosen. Static adaptive pushover analyses were performed for the sample reinforced-concrete building using each province’s design spectrum. The variations in the earthquake and structural parameters were investigated according to different geographical locations. It was determined that the site-specific design spectrum significantly influences target displacements for performance-based assessments of buildings due to seismicity characteristics of the studied geographic location.
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Jaffar, Muhammad Ismail, Hazrul Abdul Hamid, Riduan Yunus, and Ahmad Fauzi Raffee. "Fitting Statistical Distribution Functions of Air Pollutant Concentration in Different Urban Locations in Malaysia." Journal of Engineering and Science Research 7, no. 2 (2023): 7–11. http://dx.doi.org/10.26666/rmp.jesr.2023.2.2.
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Ground level ozone is an unstable substance in the atmosphere which reacts with nitrogen dioxide (NOx) in the presence of sunlight normally found near ground level. Ground level ozone is known as one of the major air quality issues worldwide. The presence of the NOx volatile organic compounds (VOCs) can influence the concentration levels of ground level ozone. This pollutant can affect crops and human health. The main aim of this research is to find the best fit distribution for urban monitoring stations in Kuala Terengganu, Kota Bharu and Alor Setar. Secondary data from 2011 to 2015 used in this study was obtained from the Department of Environment (DOE). This research used the central fitting probability distribution which is between gamma, Nakagami, lognormal and log logistic distributions. Meanwhile, the method of moments was used to estimate the parameters. The best distribution represented the monitoring station and predicted the return period of the concentration. The results show that the Nakagami distribution represented the Kuala Terengganu station from 2011 to 2015. In Kota Bharu however, the gamma distribution fit better compared to other distributions in 2013. The gamma distribution seems to fit the data from 2011 to 2014 whereas in 2015, the Nakagami distribution fit better than other distributions for the Alor Setar station. In addition, no return period was predicted for concentrations above 0.10 ppm found at the Kuala Terengganu monitoring station.
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Sarade, S., and S. R. Ruikar. "Development of a Wide Bandwidth Massive Eight Dissimilar Radiating Element Multiband MIMO Antenna for mm-Wave Application." Engineering, Technology & Applied Science Research 12, no. 5 (2022): 9166–71. http://dx.doi.org/10.48084/etasr.5133.
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This paper proposes a massive MIMO antenna operating on 6GHz frequency as millimeter-wave. It consists of eight dissimilar-shaped radiating elements. The radiating element of the antenna is designed using square shape with different cut slots. Parasitic elements and defected ground structure are introduced for the enhancement of the correlation coefficients and total active reflection coefficients of the MIMO antenna. The rectangular shape parasitic elements are placed between the square radiating patches. The ground plane consists of rectangular shape defected ground structures. The antenna is constructed on the FR-4 substrate. Parameters such as isolation, cross-correlation, and bandwidth are enhanced. The obtained through simulations antenna parameters values of return loss, isolation, cross-correlation, total active reflection coefficients, and bandwidth are less than -10dB, less than -9.30dB, less than 0.16, less than 0.00015, and greater than 200MHz respectively. The antenna operates on various bands with fractional bandwidth greater than 3% for a frequency of 6GHz. This antenna is useful for a variety of applications in wireless systems.
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Wooi, Chin-Leong, Zulkurnain Abdul-Malek, Behnam Salimi, Noor Azlinda Ahmad, Kamyar Mehranzamir, and Saeed Vahabi-Mashak. "A Comparative Study on the Positive Lightning Return Stroke Electric Fields in Different Meteorological Conditions." Advances in Meteorology 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/307424.
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Positive cloud-ground lightning is considerably more complex and less studied compared to the negative lightning. This paper aims to measure and characterize the significant parameters of positive return strokes electric field, namely, the zero-to-peak rise time, 10–90% rise time, slow front duration, fast transition rise time (10–90%), zero-crossing time, and opposite polarity overshoot relative to peak. To the best of the authors’ knowledge, this is the first time such detailed characteristics of positive lightning in Malaysia are thoroughly analyzed. A total of 41 positive lightning flashes containing 48 return strokes were analyzed. The average multiplicity is 1.2 strokes per flash. The majority of positive lightning was initiated from the primary positive charge rather than as a byproduct of in-cloud discharges. The cumulative probability distribution of rise time parameters, opposite polarity overshoot relative to peak, and slow front amplitude relative to peak are presented. A comparison between studies in four countries representing tropic, subtropic, and temperate regions was also carried out. Measured parameters in Florida, Sweden, and Japan are generally lower than those in Malaysia. Positive lightning occurrences in tropical regions should be further studied and analyzed to improve our current understanding on positive return strokes.
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Sinclair, J., C. Franks, J. F. Goodwin, R. Naemi, and N. Chockalingam. "Influence of footwear designed to boost energy return on the kinetics and kinematics of running compared to conventional running shoes." Comparative Exercise Physiology 10, no. 3 (2014): 199–206. http://dx.doi.org/10.3920/cep140010.
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Runners have sought to utilise athletic footwear as one of the mechanisms by which they might attenuate their risk of injury and improve their performance. New commercially available footwear which claims to boost energy return have been designed utilising an expanded thermoplastic polyurethane midsole. These footwear have been shown to improve running economy, but their clinical efficacy has not yet been established. This study aimed to examine the 3-D kinetics and kinematics when running in footwear that claims to promote energy return in relation to conventional running trainers. Fifteen male participants ran at 4.0 m/s (±5%) in each footwear condition. Lower extremity kinematics were collected in the sagittal, coronal and transverse planes using a 3-D motion analysis system. Simultaneous tibial acceleration and vertical ground reaction force parameters were also obtained. Impact parameters and 3-D kinematics were contrasted using paired samples t-tests. The results indicate that tibial accelerations were significantly greater in the footwear designed to improve energy return. In addition the 3-D kinematic analysis also showed that peak eversion and tibial internal rotation were significantly greater in the footwear designed to improve energy return. On the basis of these observations the current investigation suggests that these new footwear may place runners at an increased risk from chronic injury.
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Teo, Tee-Ann, and Wan-Yi Yeh. "The Benefit of the Geospatial-Related Waveforms Analysis to Extract Weak Laser Pulses." Remote Sensing 10, no. 7 (2018): 1141. http://dx.doi.org/10.3390/rs10071141.
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Waveform lidar provides both geometric and waveform properties from the entire returned signals. The waveform analysis is an important process to extract the attributes of the reflecting surface from the waveform. The proposed method analyzes the geospatial relationship between the return signals by combining the sequential waves. The idea of this method is to analyze the waveform parameters from sequential waves. Since the adjacent return signals are geospatially correlated, they have similar waveform properties that can be used to validate the correctness of the extracted waveform parameters. The proposed method includes three major steps: (1) single-waveform processing for the initial echo detection; (2) multi-waveform processing using waveform alignment and stacking; (3) verification of the enhanced weak return. The experimental waveform lidar data were acquired using Leica ALS60, Optech Pegasus, and Riegl Q680i. The experimental result indicates that the proposed method successfully extracts the weak returns while considering the geospatial relationships. The correctness and increasing rate of the extracted ground points are related to the vegetated coverage such as the complexity and density. The correctness is above 76% in this study. Because the nearest waveform has a higher correlation, the increase in distance of adjacent waveforms will reduce the correctness of the enhanced weak return.
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Salman, Maaz, Youna Jang, Jongsik Lim, Dal Ahn, and Sang-Min Han. "Novel Wilkinson Power Divider with an Isolation Resistor on a Defected Ground Structure with Improved Isolation." Applied Sciences 11, no. 9 (2021): 4148. http://dx.doi.org/10.3390/app11094148.
Full textAbstract:
A modified Wilkinson Power Divider is proposed in this paper that utilizes defected ground structure (DGS) in parallel with an isolation resistor. The proposed DGS section is incorporated between the output ports, and the isolation resistor is soldered in parallel with the DGS in the ground plane, instead of on the top plane as in a conventional Wilkinson power divider, to achieve improved or preferable isolation. The proposed design is comprised of two pairs of microstrip transmission lines with equal impedances and varied electrical lengths. The parameters of the main circuit and the DGS section are acquired separately. The parameters of the proposed main circuit are derived by applying conjugate matching theory. Dumbbell-shaped DGS is introduced in the ground plane between the output ports, which acts as a parallel resonator, yielding an attenuation pole at the resonant frequency that contributes to improved isolation. By applying the previous well-known circuit theory, the lumped elements of the equivalent circuit of the DGS were achieved. The physical dimensions of the equivalent circuit for the DGS section were obtained by three-dimensional EM simulation. The measured results show improved isolation, return loss and better bandwidth as compared with other similar works. Furthermore, the proposed circuits designed at resonating frequencies of 3 and 2 GHz presented comparatively good return losses, S11 of about −25.54 and −31.24 dB, respectively, and achieved improved isolations, S32 between the output ports, in an order of about −40.83 and −36.05 dB, respectively, which is rather exceptional and desirable.
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Tingsanchali, Tawatchai, and Thanasit Promping. "Comprehensive Assessment of Flood Hazard, Vulnerability, and Flood Risk at the Household Level in a Municipality Area: A Case Study of Nan Province, Thailand." Water 14, no. 2 (2022): 161. http://dx.doi.org/10.3390/w14020161.
Full textAbstract:
Estimating flood hazard, vulnerability, and flood risk at the household level in the past did not fully consider all relevant parameters. The main objective of this study is to improve this drawback by developing a new comprehensive and systematic methodology considering all relevant parameters and their weighting factors. This new methodology is applied to a case study of flood inundation in a municipal area of Nan City in the Upper Nan River Basin in Thailand. Field and questionnaire surveys were carried out to collect pertinent data for input into the new methodology for estimating flood hazard, vulnerability, and risk. Designed floods for various return periods were predicted using flood simulation models for assessing flood risk. The flood risk maps constructed for the return periods of 10–500 years show a substantial increase in flood risk with the return periods. The results are consistent with past flood damages, which were significant near and along the riverbanks where ground elevation is low, population density is high, and the number of household properties are high. In conclusion, this new comprehensive methodology yielded realistic results and can be used further to assess the effectiveness of various proposed flood mitigation measures.