This paper concerns with enhancing Micro Energy Grid (MEG) performance by Novel Developed Flexible AC Transmission System (D‐FACTS) based on the integration of Genetics algorithm (GA) and Adaptive Neuro‐Fuzzy Inference System (ANFIS). The design and development of MEG, with hardware demonstration, is developed at the Energy Safety and Control Laboratory (ESCL), University of Ontario Institute of Technology. The hardware/software based system includes implementation of control strategies for Distributed Energy Resources (DER) and programmable loads in a laboratory scale; and the appropriate software was developed to monitor all MEG parameters and to control the various components. The interconnection of renewable energy sources, such as wind power, solar PV and others, are implemented, studied and integrated into this MEG. Furthermore, gas based DERs operate as Combined Heat and Power (CHP) to supply both thermal and electrical loads. The design, development, and hardware setup of this MEG has been presented in a planning stage and an operational stage. Firstly, the planning stage optimizes the size and type of DERs for minimum cost and emissions. Then, in the operational stage, there will be the evaluation of the dynamic response to fine tuning the dynamic response. So a novel D‐FACTS device, Green Plug‐Energy Economizer (GP‐EE) with two DC/AC schemes, is proposed and integrated into this MEG. The integrated GA with ANFIS has been applied to control the settings of GP‐EE to fine‐tune the system dynamic response. The proposed controller ensures the adaptation of the global control error of dynamic tri‐loop regulation for GP‐EE. The proposed control strategy leads to get full MEG utilization by increasing the energy efficiency and reliability. Power factor improvement, bus voltage stabilizing, feeder loss minimization and power quality enhancement are realized and achieved. Hardware demonstration with digital simulations have been used to validate the results to show the effectiveness and the improved performance.
This paper presents a linear model for characterizing transient behavior in power conversion circuits that use wide bandgap semiconductors. It details analytical and experimental characterization of the circuit‐level transient phenomena affecting the performance of wide bandgap (WBG) semiconductors. Specifically observed behaviors including voltage overshoot, ringing, and false turn‐on are analyzed using equivalent linear circuit models supplemented with experimental characterization. The effect that the parasitic device capacitances have on each of these transient events is also investigated. In order for WBG semiconductor devices to deliver their full performance potential of significantly enhancing next generation power electronic systems, the aforementioned transient characteristics must be eliminated. Due to the agreement between the models’ predicted results and experimental waveforms, the work presented here lays the foundation for optimizing the transient performance of power conversion circuits using WBG semiconductor devices.
Focused on the issue that the robustness of traditional Mel Frequency Cepstral Coefficient (MFCC) feature degrades drastically in speaker verification in noisy environments, a kind of suitable extraction method for low SNR environments based on Gaussian Mixture Model‐Universal Background Model (GMM‐UBM) and improved Power Normalized Cepstral Coefficient (PNCC) is proposed. First, the PNCC feature is extracted after the Voice Activity Detection (VAD), which uses long term analysis to remove the effect of background noise. Then, Cepstral Mean Variance Normalization (CMVN), Feature Warping and other methods are used to improve PNCC. Finally, GMM‐UBM‐MAP is set as the baseline system for speaker verification test with TIMIT speech database, the robustness of four different features (MFCC, GFCC, PNCC and improved PNCC) are analyzed and compared in different noisy conditions. The experimental results indicate that MFCC has achieved the highest recognition rate under the environment of clean speech. By mixing the test speech with sine noises, the improved PNCC is more robust against different low‐SNR noises than other original features and its Equal Error Rate (EER) reduce significantly in low‐SNR noise environments.
In today’s post‐industrial society, mass production poses a grave threat onto the world’s ecological system and the human race. A mountain of waste covers the land which people rely on for survival. Product distributors should deliver goods and recycle waste bottles during the same time periods in order to save energy. Petroleum and other power based energy comsumes lot of natural resources. This study tries to focus on discussing optimization product distribution and waste bottle recycling routes using improved Simulated Annealing heuristics (SAH) approach. The revised and extended mathematic model and new proposed soft computing method are the main topics in this study. Through validations, the study offered foundamental data for optimization of this problem for future study. The industries also can improve their routes using improved SA heuristics approach. Future research suggests comparing more heuristics results with this SAH results.
The success of total hip arthroplasty (THA) in improving joint function and reducing pain is regarded as one of the great achievements of modern medicine. For a cementless THA stem, however, lack of initial stability leads to thigh pain and eventual loosening of the stem because of a loss of bone integration on the stem surface or continuous bone resorption around the stem. Obtaining adequate initial stability is one of the important factors for good short‐term and long‐term clinical outcomes. While most of the cementless stems are made of either cobalt‐chrome‐molybdenum (CoCrMb) or titanium‐aluminum‐ vanadium (TiAlV) alloys, we have focused on an expandable cementless stem utilizing nickel‐titanium (Ni‐Ti) shape memory alloy (SMA). In this study, the expandable stem with SMA was evaluated in vitro, specifically testing to determine if the stem is able to achieve rigid initial stability in a medullary cavity under cyclic loadings. The proposed stem has Ni‐Ti SMA expandable blades on the stem surfaces. For shape memorization, the SMA was restrained at an expanded shape under appropriate thermo‐ mechanical treatments. At the time of implantation into bone, the SMA with a contracted shape was kept below the martensite transformation temperature. After implantation, the SMA blades undergo reverse transformation due to body temperature, accompanied by a change from the contracted shape to the expanded shapes. The shape change results in a residual pressure between the bone and the stem. In mechanical tests, the stem with SMA showed better initial stability, in terms of relative micromotions at the stem‐bone interface, under cyclic loadings. After 120 loadings, micromotion of 11 m was observed on the stem with SMA, while the micromotion on the stem without SMA was 122 m. Use of an expandable stem utilizing SMA is effective enough for rigid initial stability.
As an alternative approach to traditional ergonomics study, the modelling and simulation through manikin could help researchers to access the ergonomics constrain in craft shop actively. In current study, with focus on typical scenario of semiconductor fabrication workshop, the posture of worker’s during material handing was simulated and the musculoskeletal loads on lumber and shoulder of manikin was predicted, especially on L4/L5 joint of lumber. Accodingly, the improved working posture and related paramaters was proposed according to regional anthropometry reference.
Lightning impulse has been one of the important problems for insulation design of power systems and it is still the main cause of outages of transmission and distribution lines. The lightning return‐stroke current and the charge delivered by the stroke are the most important parameters to assess the severity of lightning strokes to power lines and apparatus. This paper presents the effects of many tower, ground parameters on the backfloshover voltage level. Also demonstrate the results used to determine the lightning backflashovers level on 230KV transmission lines utilized by Saudi Electric Company (SEC) in Saudi Arabia, using two well known approaches CIGRE, and the simplified method. The studies include lightning flashovers, backflash analysis, as dependent on the tower design parameters which is considered the main parameters that reduce the rate of lightning bachflashovers in the transmission lines. The study results can be applied to reduce the number lightning flashovers and therefore reduce the transmission lines
This study is aimed to calculate the range of motion of total hip arthroplasty (THA) until implant-to-implant impingement and dislocation occur, and to calculate resisting moments to dislocate the hip using non-linear finite element (FE) methods. To analyse the dislocation objectively and to clarify the distinction between implant-to-implant impingement and dislocation, three-dimensional FE models of hybrid THA components were generated. In this study, posterior dislocation-prone maneuvers such as flexion, adduction, internal rotation, and their combinations were analysed. The analyses were started with the femoral component oriented in a manner corresponding to the hip being flexed to the impingement occurrence angles at various internal rotation and adduction angles. The muscle forces were also considered by applying hip joint forces during the analyses. As results, the angles of internal rotation and adduction affected both impingement and dislocation angles of flexion. The flexion angles both at impingement and at dislocation decreased by increasing the internal rotation angles. Although the peak flexion moment todislocate the hip joint increased by increasing the internal rotation angle, it didn't always increase with an increase in the adduction angle. The highest value of the peak flexion moment to dislocate the hip was observed at 30° of internal rotation. Conversely, the lowest value of the peak flexion moment was observed at 10° of adduction. This lowest value means that the hip joint is easy to be dislocated at this adduction angle by an external torque.
Combined Public Key (CPK) provides a common method to turn the existing public key into an identity-based public key. CPK can solve the hard problem of large-scaled key management and identity authentication[1], and can solve the new problem of dealing with the quantum exhaustion attack.
With appearance of deregulated electricity markets, line congestions in transmission systems is considered as critical problem for power system which may prevent dispatching all of the contracted power transactions. Many studies have been carried out to express techniques for congestion management (CM). In this paper real and reactive power rescheduling of generators approach is utilized. This method includes two steps. First one is optimum selection of generators on the basis of sensitivities of generator to power flow on congested line/lines. Next step is optimal rescheduling of generators and identification of capacitors required to provide real and reactive power support for CM. Optimization process in this paper is carried out using big bang-big crunch (BB-BC) algorithm which is improved by particle swarm optimization (PSO) method as hybrid BB-BC (HBB-BC) optimization for the first time. Effectiveness of proposed method has been tested on IEEE 30-bus system, the 39-bus New England system, and 75-bus Indian system and compared with the other proposed methodologies.
