Double-deck elevators are a very efficient mode of transport, especially in high rise buildings. This is due to the fact that they reduce the number of stops in a round trip (leading to a smaller value of the round trip time hence a higher handling capacity) and take up less space of the core of the building leading to high space usage efficiency. This paper provides a comprehensive treatment of the double-deck elevator traffic calculations. It derives an exact set of equations to find the value of the round trip time under incoming traffic conditions, for the cases of equal and unequal floor populations. Moreover, equations have also been derived for two performance coefficients. The first coefficient is called the passenger transfer efficiency coefficient and is representative of the time taken by passenger to alight from the double-deck elevator. The second coefficient is called the coincidental stopping coefficient and is representative of the stopping efficiency. All the results from the equations have been verified using the Monte Carlo simulation method. The method of stepwise verification has been used in order to verify the equations. Under stepwise verification, the equations are derived in stages and each stage is verified against the results from the Monte Carlo Simulation method. The paper ends by suggesting methods of dealing with two of the irregular conditions. Namely two cases are discussed: the case where the number of floors above the main entrance is odd; and the case where the floor heights are unequal and the rated speed is not attained in one double floor journey. Practical application: This paper presents a full set of equations that allow the elevator system designer to fully assess the expected performance of the double-deck elevator system under incoming traffic conditions. These equations (manually or within a software program) can be used to carry out a full design (thus selecting the number, speed, and capacity of the double-deck elevators). © The Chartered Institution of Building Services Engineers 2016.
|Mechatronics Engineering||Mechatronics Engineering||3/1/2017||Mechatronics Engineering|
This paper presents the design and testing of a gentle pump prototype that is operated by a rotating magnetic field. The pump targets applications in which the pumped fluid contains stress sensitive microparticles which may be damaged when subjected to the high stress levels prevalent in conventional pumps. The prototype was tested in-vitro using blood from human volunteers, and according to published international protocols for the assessment of the hemolytic properties of continuous flow blood pumps used in extracorporeal or implantable circulatory assist devices. The normalized index of hemolysis (NIH) was found to be about 0.007, which is comparable with that obtained from top ranking blood pumps available in the market today. © 2015 IEEE.
|Mechatronics Engineering||Mechatronics Engineering||12/8/2015||Mechatronics Engineering|
As the mathematical procedure of system modelling often leads to a comprehensive description, which causes significant difficulty in both analysis and control synthesis, it is necessary to find lower order models, which maintain the dominant characteristics of the original system. In this paper, different soft computing (named as artificial intelligence (AI)) techniques are presented, applied, and analysed for model order reduction (MOR) of multi time scale systems with the objective of substructure preservation. In addition to that, we investigate the firefly optimization technique for MOR with substructure preservation. The analysis is concerned with the optimization approach and quality of method performance. © 2015 TSI® Press.
|Mechatronics Engineering||Mechatronics Engineering||1/2/2016||Mechatronics Engineering|
Purpose: The purpose of this paper is to introduce new implementations for parallel processing applications using bijective systolic networks and their corresponding carbon-based field emission controlled switching. The developed implementations are performed in the reversible domain to perform the required bijective parallel computing, where the implementations for parallel computations that utilize the presented field-emission controlled switching and their corresponding many-valued (m-ary) extensions for the use in nano systolic networks are introduced. The second part of the paper introduces the implementation of systolic computing using two-to-one controlled switching via carbon-based field emission that were presented in the first part of the paper, and the computational extension to the general case of many-valued (m-ary) systolic networks utilizing many-to-one carbon-based field emission is also introduced. Design/methodology/approach: The introduced systolic systems utilize recent findings in field emission and nano applications to implement the functionality of the basic bijective systolic network. This includes many-valued systolic computing via field-emission techniques using carbon-based nanotubes and nanotips. The realization of bijective logic circuits in current and emerging technologies can be very important for various reasons. The reduction of power consumption is a major requirement for the circuit design in future technologies, and thus, the new nano systolic circuits can play an important role in the design of circuits that consume minimal power for future applications such as in low-power signal processing. In addition, the implemented bijective systems can be utilized to implement massive parallel processing and thus obtaining very high processing performance, where the implementation will also utilize the significant size reduction within the nano domain. The extensions of implementations to field emission-based many-valued systolic networks using the introduced bijective nano systolic architectures are also presented. Findings: Novel bijective systolic architectures using nano-based field emission implementations are introduced in this paper, and the implementation using the general scheme of many-valued computing is presented. The carbon-based field emission implementation of nano systolic networks is also introduced. This is accomplished using the introduced field-emission carbon-based devices, where field emission from carbon nanotubes and nano-apex carbon fibers is utilized. The implementations of the many-valued bijective systolic networks utilizing the introduced nano-based architectures are also presented. Practical implications: The introduced bijective systolic implementations form new important directions in the systolic realizations using the newly emerging nano-based technologies. The 2-to-1 multiplexer is a basic building block in “switch logic,” where in switch logic, a logic circuit is realized as a combination of switches rather than a combination of logic gates as in the gate logic, which proves to be less costly in synthesizing multiplexer-based wide variety of modern circuits and systems since nano implementations exist in very compact space where carbon-based devices switch reliably using much less power than silicon-based devices. The introduced implementations for nano systolic computation are new and interesting for the design in future nanotechnologies that require optimal design specifications of minimum power consumption and minimum size layout such as in low-power control of autonomous robots and in the adiabatic low-power VLSI circuit design for signal processing applications. Originality/value: The introduced bijective systolic implementations form new important directions in the systolic realizations utilizing the newly emerging nanotechnologies. The introduced implementations for nano systolic computation are new and interesting for the design in future nanotechnologies that require optimal design specifications of high performance, minimum power and minimum size. © 2016, © Emerald Group Publishing Limited.
|Computer Engineering||Computer Engineering||3/31/2016||Computer Engineering|
In this paper user verification and identification system on touch screen mobile devices is proposed. The system examines the keystroke dynamics and uses it as a second authentication factor. The study proposes a prototype for a keyboard application developed for collecting timing and non-Timing information from keystroke dynamics. In addition to other mentioned in literature studies, we propose complex password combination, which consists of text, numbers, and special characters. Strengthening access control using artificial neural networking model is suggested. Neural network model based on multilayer perceptron classifier which uses back propagation algorithm is proposed. This paper presents a unique approach for combining timing and non-Timing features together, as it includes several non-Timing features such pressure, size, and position in addition to the duration time features. Several experiments have been done based on specific machine learning for data mining and classification toolkit named WEKA. The obtained results show that keystroke dynamics provides acceptable level of performance measures as a second authentication factor. The distinguishable role for non-Timing features beside the timing features is demonstrated. These features have a significant role for improving the performance measures of keystroke dynamic behavioral authentication. The proposed model achieves lower error rate of false acceptance of 2.2%, false rejection of 8.67%, and equal error rate of 5.43% which are better than most of references provided in the literature. © 2016 IEEE.
|Computer Engineering||Computer Engineering||8/1/2016||Computer Engineering|
This paper presents a sequence transcription approach for the automatic diacritization of Arabic text. A recurrent neural network is trained to transcribe undiacritized Arabic text with fully diacritized sentences. We use a deep bidirectional long short-term memory network that builds high-level linguistic abstractions of text and exploits long-range context in both input directions. This approach differs from previous approaches in that no lexical, morphological, or syntactical analysis is performed on the data before being processed by the net. Nonetheless, when the network is post-processed with our error correction techniques, it achieves state-of-the-art performance, yielding an average diacritic and word error rates of 2.09 and 5.82 %, respectively, on samples from 11 books. For the LDC ATB3 benchmark, this approach reduces the diacritic error rate by 25 %, the word error rate by 20 %, and the last-letter diacritization error rate by 33 % over the best published results. © 2015, Springer-Verlag Berlin Heidelberg.
|Computer Engineering||Computer Engineering||6/1/2015||Computer Engineering|
In this work, supercritical extraction of Jordanian oil shale was investigated experimentally using a batch autoclave device. Operating conditions such as solvent type, mixing time, temperature, pressure, and particle size effects on oil recovery from oil shale have been studied. The results indicated that oil yield increases with the increase of pressure and temperature. The maximum extract yields of 15 and 16 wt% were obtained at 42 bars and 318°C with toluene for El-Lajjun and Sultani shales, respectively. Supercritical fluid extraction (SFE) has shown to be an efficient technique since the extracted yield was 55% more than the yield obtained using the classical Fischer Assay retorting process. © 2016 Taylor & Francis Group, LLC.
|Chemical Engineering||Chemical Engineering||3/31/2016||Chemical Engineering|
A Ca/Na-aluminosilicate was synthesized from kaolin and limestone via the hydrothermal reaction and was used for CO2 capture from a gas stream. Synthesis was performed at several combinations of temperature, pressure, kaolinite to limestone mass ratio, and the reaction time. The products were characterized by determining the crystalinity, surface morphology, surface area, and the pore size distribution. When the reaction temperature and pressure are increased, the sodium hydroxide concentration has a significant effect on the formation of novel Ca/Na-aluminosilicate phases. X-ray diffraction shows that a mixture of Gehlenite Ca2Al(Al1.22Si0.78O6.78)OH0.22 (43 wt %) and Stilbite Na5.76Ca4.96(Al15.68Si56.32O144) (57 wt%) is produced in 36 M NaOH at 200 °C and 15 bar. The adsorption capacity of the above product for CO2 from a gas stream increased with temperature, reaching a CO2 uptake of 294.7 mg/g at an equilibrium pressure of 45 bar and a temperature of 150 °C. Thermodynamic studies show spontaneous and endothermic adsorption behavior with a ΔHads of 4.64 kJ/mol, ΔSads of 25.25 J/mol.K, and ΔGads of -6.09 kJ/mol obtained at 150 °C. The CO2 adsorption/cycling process were repeated and it was found that the capacity of the novel adsorbent decreases in the second cycle and remains constant after that. This suggests chemisorption process took place on the fresh adsorbent and physical adsorption occurred at higher cycles. © 2015 Elsevier Ltd. All rights reserved
|Chemical Engineering||Chemical Engineering||3/1/2016||Chemical Engineering|
This work investigates the status and potential of utilizing biomass as an energy source in Jordan. The amount of waste and residue is estimated to be 6.680 million tons for the year 2011. Two scenarios were investigated: biogas production and thermal treatment. The amount of biogas that can be produced from various biomass sources in Jordan is estimated at 428 MCM. The equivalent annual power production is estimated at 698.1 GW h. This is equivalent to about 5.09% of the consumed electricity (13,535 GW h) and 39.65% of the imported electricity in 2011. The alternative scenario of thermal treatment was investigated. The total theoretical thermal energy that can be obtained assuming 70% conversion efficiency is equivalent to 779 thousand toe (5.33 million barrels of crude oil) which amounts to 10.2% of the total primary energy consumed in 2011. Due to biomass collection and recovery challenges, the energy availability factor varies for the different resources. Hence, contribution of the different biomass resources can significantly vary. © 2013 Elsevier Ltd. All rights reserved
|Chemical Engineering||Chemical Engineering||1/1/2014||Chemical Engineering|
Jordan has significant oil shale deposits occurring in 26 known localities. Geological surveys indicate that the existing deposits underlie more than 60% of Jordan's territory. The resource consists of 40 to 70 billion tones of oil shale, which may be equivalent to more than 5 million tones of shale oil. Since the 1960s, Jordan has been investigating economical and environmental methods for utilizing oil shale. Due to its high organic content, is considered a suitable source of energy. This paper introduces a circulating fluidized bed combustor that simulates the behavior of full scale municipal oil shale combustors. The inside diameter of the combustor is 500 mm, the height is 3000 mm. The design of the CFB is presented. The main parameters which affect the combustion process are elucidated in the paper. The size of the laboratory scale fluidized bed reactor is 3 kW, which corresponds to a fuel-feeding rate of approximately 1.5 kg/h. © 2012 American Institute of Physics
|Mechanical Engineering||Mechanical Engineering||8/1/2012||Mechanical Engineering|
A power series solution is presented for the free vibrations of simply supported beams resting on elastic foundation having quadratic and cubic non-linearities. The time-dependence is assumed harmonic and the problem is posed as a non-linear eigenvalue problem. The spatial variable is transformed into an independent variable that satisfies the boundary conditions. This permits a power series expansion of the beam motion in terms of the new variable. A recurrence relation is obtained from the governing equation and used in conjunction with the Rayleigh energy principle to compute the natural frequencies. The results show that, for a first order approximation, only the lower frequencies and first mode shape are significantly affected by the cubic non-linearity. © 2002 Elsevier Science Ltd. All rights reserved
|Mechanical Engineering||Mechanical Engineering||8/1/2003||Mechanical Engineering|
In this work a simplified formula for the stress correction factor in terms of the crack depth to the beam height ratio, f(a/h), is presented. The modified formula is compared to a well-known similar factor in the literature, and shows a good agreement for a/h lower than 0.5. The modified formula is used to examine the lateral vibration of an Euler-Bernoulli beam with a single-edge open crack. This is done through introducing the flexibility scalar. This scalar can be generated from the Irwins's relationship using the modified factor f(a/h). The crack in this case is represented as rotational spring. With the modified model, beam configurations with classical and non-classical support conditions could be studied. The mode shapes for the cracked and the uncracked beam are obtained using this model. They are displayed graphically for selected values of the system parameters; the crack depth ratio a/h, and the crack location ratio s/L. The shift in the mode shape due to the existence of a crack is highlighted. The obtained results showed good agreement with similar published studies. © 2007 Elsevier Inc. All rights reserved
|Mechanical Engineering||Mechanical Engineering||1/1/2009||Mechanical Engineering|
The ultra-wideband (UWB) antennas are required to cover high impedance bandwidth such that the return loss (RL) is greater than 10 dB with improved gain and radiation efficiency which are required for the different applications. In this UWB range (3.1-10.6 GHz), there are other applications, using narrow band frequency bands, such as WiMAX (3.3-3.7) GHz, WLAN (5.15-5.825) GHz and others. In this case it is needed to filter out these different applications which interfere with the UWB system. This can be performed by redesigning the printed circuit antenna to have an inherent characteristics with band rejection behavior to eliminate some or all of these interfering signals. © 2016 IEEE
|Electrical Engineering||Electrical Engineering||6/26/2016||Electrical Engineering|
The objective of the paper is to study the effect and impact of installing PV systems on the operation of protection system components of a local distribution network.
|Electrical Engineering||Electrical Engineering||9/22/2015||Electrical Engineering|
As the mathematical procedure of system modelling often leads to a comprehensive description, which causes significant difficulty in both analysis and control synthesis, it is necessary to find lower order models, which maintain the dominant characteristics of the original system. In this paper, different soft computing (named as artificial intelligence (AI)) techniques are presented, applied, and analysed for model order reduction (MOR) of multi time scale systems with the objective of substructure preservation. In addition to that, we investigate the firefly optimization technique for MOR with substructure preservation. The analysis is concerned with the optimization approach and quality of method performance. © 2015 TSI® Press
|Electrical Engineering||Electrical Engineering||1/1/2016||Electrical Engineering|
Natural light is one of the most important elements in architecture, helping to transform spaces and save energy. Day lighting design starts with the selection of a building site and continues as long as the building is occupied. This study is seeking to enhance buildings envelope facades with architectural aesthetic potential and optimizing daylight to boost both the quality of health and wellbeing as well as improving the building energy efficiency. The primary control of daylight should be made by the choice of the opening size and Position. This study tries to form the architectural composition of façade which can be Measured by using digital technology involved in building physics, through Computational process of cellular automata (CA). Cellular automata are the computational method which can simulate the process of Growth by describing a complex system by simple individuals following simple rules. The connection to architecture is the ability of cellular automata to generate patterns, which is useful to propose an innovative design strategy. © Research India Publications.
|Architecture Engineering||Architecture Engineering||5/1/2016||Architecture Engineering|
This paper presents an empirical study of children's outdoor spatial behavior in the Al-Rawdah multi-family housing development built in Amman, the capital of Jordan. Research methods incorporate a variety of interactive methodologies ranging from systematic observation and behavioral mapping of a range of the children's behavior in outdoor places to in depth interviews. Observational categories include information on users (age, sex, companionship, size of group, etc.), on settings where behavior was observed (type of outdoor space), and on the types of behavior observed including physical, social, and cognitive play. The study covers a broad range of developmental concerns including children's cognitive mapping of the macro-outdoor environment and children's play behavior and social interaction in specified and unspecified play settings. Field survey of children's spatial behavior in Al-Rawdah housing development has supported early research findings and shown that not only was the amount of space important in prompting the type of play and outdoor activities observed in school-age children, but also the scarcity or abundance of social interaction opportunities within that space. The findings illustrate the complex interaction of physical and social factors in determining how communal outdoor areas in multi-family housing projects are used and perceived. The conclusion emphasize that housing design must be understood in the context of users needs and behavioral attitudes in outdoor areas. However, it should not be stereotyped. Cultural norms, lifestyles and the socio-economic system of users affect how individuals, especially children, use communal outdoor spaces in the residential setting. The effects of physical environmental variables can only by understood when studied in interaction with social environmental variables. The results are supportive of the interaction theory of environment-behavior relations
|Architecture Engineering||Architecture Engineering||6/2/2002||Architecture Engineering|
Despite the historic origin of Greater Amman Municipality (GAM), it is considered a modern city. The development of GAM through the 19th and 20th century was dramatic and massive. Since the beginning of the 21st century and precisely since 2002, GAM started a large property development project that forms the cornerstone of GAM development strategy. GAM's situation is a mixture between state control and economic liberalism in which urban development is determined by the planning vision of attracting foreign investment and reducing restrictions to free enterprise. GAM presents an example of global economic forces that occur in a developed society. This paper examines the development of GAM, focusing on its major urban problems and suggesting some solutions. A review of the recent megaprojects now taking place in GAM is carried out indicating the urgent need for a specialized committee to lay down a comprehensive metropolitan plan for GAM for at least the next 10 years. The last comprehensive plan in 1987 cannot continue to serve GAM's recent overwhelming urban property development. © 2010 ASCE
|Architecture Engineering||Architecture Engineering||6/2/2010||Architecture Engineering|
Culverts have been used to transmit surface drainage under roadways in place of typical short-span bridges because they provide an economical construction system. In this paper, a numerical study using a finite-element method is presented to study the behavior of reinforced concrete box culverts (CBC) with different dimensions and thicknesses under different soil fill heights. Four box-culvert sections were selected with width-to-height ratios of 2:1, 1:1, 2:3, and 1:2. Each section has a constant clear hydraulic area of 6.7 × 10⁶ mm². Different thicknesses of CBC were investigated for each section. Hyperbolic stress-strain parameters for nonlinear finite-element analysis in soil masses were used. The required area of steel and deflection of culvert were calculated from each finite-element run. It is concluded that the CBC with a width-to-height ratio of 2:1 is suitable for all soil fill heights examined (4.6, 9.1, 13.7, and 18.3 m). Finally, the paper presents a simple linear regression formula to predict section thickness for any soil fill height when using CBC-1
|Civil Engineering||Civil Engineering||11/1/2017||Civil Engineering|
As a result of quick progression in computer and information technologies, computer modeling has become a vital tool in watershed research and management practices. Stanford Watershed Model (SWM) is an integrated physically based Watershed model that can be used to simulate water flow stream/canal network and overland runoff, interflow and evaporation by considering the interaction between surface water and sub-surface water. The objective of this study is to apply the SWM in order to estimate the rainfall-runoff relationship for Wadi Wala streamflow semi arid area with an average annual rainfall of about 300 mm/yr and a catchment area of 1800 km 2. SWM has been widely accepted as a tool to synthesize a continuous hydrograph of hourly or daily streamflow. Sensitivity analysis, as well as trial and error adjustment techniques were used for the optimization of the number of parameters of the model. Comparing estimated and measured surface runoff for Wala valley indicated that the model is considerably efficient in predicting the total annual surface runoff from rainfall for similar watersheds
|Civil Engineering||Civil Engineering||3/31/2016||Civil Engineering|
This study summarizes the results of experimental push-out tests conducted on concrete-filled steel tubes (CFST) incorporating rubberized concrete with the main variables being the recycled rubber replacement ratio, certain sizes of steel tubes having circular and square sections and ages of testing (at 28 days and one year). In addition, 150 mm-cubes were prepared using rubberized concrete mixtures to investigate the impact of shredded rubber contents on the compressive strength of concrete. Four concrete mixtures were designed at a constant water-to-cement ratio of 0.5 and with a cement content of 400 kg/m3. The mixtures were produced by replacing the fine aggregate with crumb-shredded tires at designated replacement levels of zero, 10%, 20% and 30% by total fine aggregate volume. Test results indicated that the use of rubber crumb increased the fresh-state workability and had an adverse influence on the compressive strength of concrete. The details of bond stress and the interface core slip in CFST specimens were estimated and the developed bond mechanisms were explained. The push-out testing of CFST specimens displayed a reduction in the bond strength and the ductility with increasing concrete age. © 2016 Elsevier Ltd. All rights reserved
|Civil Engineering||Civil Engineering||6/1/2016||Civil Engineering|
This paper presents a medium access control protocol that is designed for wireless cognitive radio ad hoc networks (W-CRAHN). The cognitive radio network consists of a number of channels and a group of secondary users or subscribers. Each subscriber has access to a certain number of the available channels. The channels vary in their availability to the secondary users according to the activity of the primary users, so some channels are more common (can be accessed by a large number of subscribers) than other channels (accessed by less number of subscribers). Subscribers inside the cognitive network are connected in pairs, and each pair has a set of channels in common, so the pair can choose from a dedicated list known as the common channel list (CCL) to establish a communication link. A feature of this proposed protocol is the "random pairing algorithm" which enables each subscriber to connect to each subscriber inside the network. In this work, we show how the proposed method helps in adding more flexibility and providing more freedom to the subscribers of the network as compared of the other previously suggested methods. This results in a better quality of service offered by the network.
|Electrical Engineering||Electrical Engineering||4/26/2016||Electrical Engineering|
The main purpose in this work is to enhance relay technique in underlay cognitive radio scheme through estimating the best path between the secondary source and the secondary destination under the power interference constraint of the primary user. A protocol is proposed based on the cooperation process between the secondary relay nodes in the system in order to establish the best path at low complexity without exceeding the interference threshold of theprimary user. Performance analyses, through simulation, of the suggested protocol shows great enhancement in network outage probability when compared with direct path model and one relay node based-model.
|Electrical Engineering||Electrical Engineering||2/11/2015||Electrical Engineering|
IEEE 802.22 wireless regional area network (WRAN) is a cognitive radio-based network. WRANs are intended to be deployed by different service providers and designed to opportunistically utilize the unused TV bands. WRANs have to self-coexist with other overlapped WRANs in a distributed manner. Therefore, every service provider tries to acquire a band free of interference from others to satisfy a required quality of service. This self-coexistence problem is one of the major challenges in WRAN. In this paper, we propose a Markov-based distributed approach for mitigating this problem. We model the problem as an absorbing discrete-time Markov chain. In this model, if two or more overlapped WRANs select the same band, then each one should either stay or switch to another band according to a certain switching probability. This process continues until each one of the WRANs finds an interference-free band. In this case, the Markov chain reaches the absorbing state. This model is employed to find the optimal switching probability, which in turn minimizes the time required to reach the absorbing state. The switching probability is numerically found as a function of the number of overlapped WRANs and available bands. Extensive simulation has been conducted to validate our numerical results.
|Electrical Engineering||Electrical Engineering||12/1/2014||Electrical Engineering|
Most of the schemes that were proposed to improve the performance of transmission control protocol (TCP) over mobile ad hoc networks (MANETs) are based on a feedback from the network, which can be expensive (require extra bandwidth) and unreliable. Moreover, most of these schemes consider only one cause of packet loss. They also resume operation based on the same stand-by parameters that might vary in the new route. Therefore, we propose two techniques for improving the performance of TCP overMANETs. The first one, called TCP with packet recycling (TCP-PR), allows the nodes to recycle thepackets instead of dropping them after reaching the retransmission limit at the MAC layer. In the second technique, which is called TCP with adaptive delay window (TCP-ADW), the receiver delays sending TCP ACK for a certain time that is dynamically changed according to the congestion window and the trip time of the received packet. TCP-PR and TCP-ADW are simple, easy to implement, do not require network feedback, compatible with the standard TCP, and do not require distinguishing between the causes of packet loss. Our thorough simulations show that the integration of our two techniques improves theperformance of TCP over MANETs.
|Electrical Engineering||Electrical Engineering||3/1/2014||Electrical Engineering|
In this paper, the solution of inverse kinematics problem of robot manipulators using genetic algorithms (GA) is presented. Two versions of genetic algorithms are used which include the conventional GA and the continuous GA. The inverse kinematics problem
is formulated as an optimization problem based on the concept of minimizing the accumulative path deviation in the absence of any obstacles in the workspace. Simulation results show that the continuous GA outperforms the conventional GA from all aspects. The superiority of the continuous GA is seen in that it will always provide smooth and faster solutions as compared with the conventional GA.
|Mechatronics Engineering||Mechatronics Engineering||1/1/2016||Mechatronics Engineering|
A robust computational technique for model order reduction (MOR) of multi-time-scale discrete systems (single input single output (SISO) and multi-input multioutput (MIMO)) is presented in this paper. This work is motivated by the singular perturbation of multi-time-scale systems where some specific dynamics may not have significant influence on the overall system behavior. The new approach is proposed using genetic algorithms (GA) with the advantage of obtaining a reduced order model, maintaining the exact dominant dynamics in the reduced order, and minimizing the steady state error. The reduction process is performed by obtaining an upper triangular transformed matrix of the system state matrix defined in state space representation along with the elements of B, C, and D matrices. The GA computational procedure is based on maximizing the fitness function corresponding to the response deviation between the full and reduced order models. The proposed computational intelligence MOR method is compared to recently published work on MOR techniques where simulation results show the potential and advantages of the new approach.
|Mechatronics Engineering||Mechatronics Engineering||1/1/2015||Mechatronics Engineering|
A new model order reduction (MOR) technique for linear multi time scale discrete systems with substructure preservation is presented in this paper. The reduction process is performed based on two steps; system transformation and singular perturbation approximation (SPA). The system transformation step is performed to maintain the system substructure preservation, while the SPA is used to obtain the intended reduced order model. The new MOR approach is presented with the advantages of obtaining the desired reduced order model, minimizing the steady state error, preserving a system substructure (dominant dynamics), in addition to the advantage of a relatively fast convergence of the system steady state behavior. The proposed modelling technique is investigated by applying it to a power system model with a comparison of quality of performance to other model order reduction techniques. The potential and advantages of the new approach are clearly seen in the illustrative simulation results.
|Mechatronics Engineering||Mechatronics Engineering||1/1/2015||Mechatronics Engineering|
Magneto-hydrodynamic (MHD) principle is an important interdisciplinary field. One of
the most important applications of this effect is pumping of materials that are hard to pump using
conventional pumps. In this work, the progress achieved in this field is surveyed and organized
according to the type of application. The literature of the past 27 years is searched for the major
developments of MHD applications. MHD seawater thrusters are promising for a variety of applications requiring high flow rates and velocity. MHD molten metal pump is important replacement
to conventional pumps because their moving parts cannot stand the molten metal temperature.
MHD molten salt pump is used for nuclear reactor coolants due to its no-moving-parts feature.
Nanofluid MHD pumping is a promising technology especially for bioapplications. Advantages
of MHD include silence due to no-moving-parts propulsion. Much progress has been made, but
with MHD pump still not suitable for wider applications, this remains a fertile area for future research.
|Mechatronics Engineering||Mechatronics Engineering||1/1/2016||Mechatronics Engineering|
The optimum implementation of a thermoelectric generator (TEG) is investigated. In order to study the feasibility of such system, a model for a large-scale TEG is designed and optimized to convert thermal energy into electricity. The mathematical formulation of the system comprising multiple TEG modules is modeled and simulated. It is assumed that the source of the thermal energy comes from concentrated solar receiver. Temperature solutions and heat transfer coefficients are obtained. The major geometrical and thermal parameters affecting the efficiency of the system are identified and optimized for best performance. Design aspects, such as the leg length, and heat transfer conditions have a significant impact on generated output power and efficiency.
|Mechatronics Engineering||Mechatronics Engineering||2/8/2016||Mechatronics Engineering|