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Full-Text Articles in Engineering
Effect Of Renewable Distributed Generators On The Fault Current Level Of The Power Distribution Systems, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Masoud Farhoodnea, Marjan Mohammadjafari
Effect Of Renewable Distributed Generators On The Fault Current Level Of The Power Distribution Systems, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Masoud Farhoodnea, Marjan Mohammadjafari
Dr. Hadi Zayandehroodi
The presence of renewable distributed generator (RDG) in a distribution system will have unfavorable impact on the operating system because the distribution system is no longer radial in nature and is not supplied by a single main power source. With RDGs in a distribution network, it brings about a change in the fault current level of the system and causes many problems in the protection system, such as false tripping of protective devices, protection blinding, an increase and decrease in short-circuit levels. This paper presents the effect of RDGs on the fault current level of the system. The operating protection …
A Novel Neural Network And Backtracking Based Protection Coordination Scheme For Distribution System With Distributed Generation, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Masoud Farhoodnea
A Novel Neural Network And Backtracking Based Protection Coordination Scheme For Distribution System With Distributed Generation, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Masoud Farhoodnea
Dr. Hadi Zayandehroodi
With the increased installation of renewable energy based distributed generations (DGs) in distribution systems, it brings about a change in the fault current level of the system and causes many problems in the current protection system. Hence, effective protection schemes are required to ensure safe and selective protection relay coordination in the power distribution system with DG units. In this paper, a novel adaptive protection scheme is proposed by integrating fault location with protection relay coordination strategies. An automated fault location method is developed using a two stage radial basis function neural network (RBFNN) in which the first RBFNN determines …
Innovative Calorimetric Ac Loss Measurement Of Htsc For Power Applications, K See, C Cook, S Dou
Innovative Calorimetric Ac Loss Measurement Of Htsc For Power Applications, K See, C Cook, S Dou
Christopher Cook
The applications of high-temperature superconductors (HTS) in electric power components have been widely reported and various studies have been made to define their alternating current (AC) losses-a key design parameter for many practical high power electrical engineering applications. However, very few studies over the range 25 to 45 K have been conducted even though this is one of the favored temperature ranges for cost-effective applications of HTS. Methods and techniques used to characterize and measure these losses have been so far grouped into `electrical' and `calorimetric' approaches with external conditions set to resemble the application conditions. In this paper, we …
Transport Critical Current Of Mgb2 Wires: Pulsed Current Of Varying Rate Compared To Direct Current Method, K See, X Xu, J Horvat, C Cook, S. Dou
Transport Critical Current Of Mgb2 Wires: Pulsed Current Of Varying Rate Compared To Direct Current Method, K See, X Xu, J Horvat, C Cook, S. Dou
Christopher Cook
The measurement of transport critical current (Ic) forMgB2 wires and tapes has been investigated with two different techniques, the conventional four-probe arrangement with direct current (DC) power source, and a tailored triangle pulse at different rates of current change. The DC method has been widely used and practiced by various groups, but suffers from inevitable heating effects when high currents are used at low magnetic fields. The pulsed current method has no heating effects, but the critical current can depend on the rate of the current change (dI/dt) in the pulse. Our pulsed current measurements with varying dI/dt show that …
Evaluation Of Control Techniques For Dip Transfer Gas Metal Arc Welding, Gary Dean, John Norrish, Christopher D. Cook
Evaluation Of Control Techniques For Dip Transfer Gas Metal Arc Welding, Gary Dean, John Norrish, Christopher D. Cook
Christopher Cook
Dip transfer gas metal arc welding (GMAW) is used extensively for high productivity welding of thin sheet steel, and is also useful for positional welding of thicker section steels. Unfortunately in the past, the process has gained a reputation for fusion defects, which becomes more apparent when welding traditionally difficult materials such as coated steels. This reputation can be attributed in some instances to the method of control used and the changeable nature of variables crucial to controlling heat transfer during the welding process. The paper examines the relationship between weld fusion, heat input and current for coated steel welding …
Drilling Of Carboncomposites Using Aoneshotdrillbit. Part I: Five Stage Representation Of Drilling And Factors Affecting Maximum Force And Torque, Marta Fernandes, C. Cook
Drilling Of Carboncomposites Using Aoneshotdrillbit. Part I: Five Stage Representation Of Drilling And Factors Affecting Maximum Force And Torque, Marta Fernandes, C. Cook
Christopher Cook
The thrust force and torque produced during drilling contain important information related to the quality of the hole and the wear of the drillbit[1]. In this paper, the force and torque produced during drilling of carbon fibre using a ‘oneshot’ drillbit is investigated. The signals in the time domain were divided into stages and common problems and defects associated with each stage discussed. It is also shown how tool wear and thickness of the workpiece affect the thrust force and torque throughout the drilling process. The findings of this paper are used to develop a mathematical model of the maximum …
Bending Modeling And Its Experimental Verification For Conducting Polymer Actuators Dedicated To Manipulation Applications, Christopher Cook, Gursel Alici, Brian Mui
Bending Modeling And Its Experimental Verification For Conducting Polymer Actuators Dedicated To Manipulation Applications, Christopher Cook, Gursel Alici, Brian Mui
Christopher Cook
No abstract provided.
New General Algorithm For Describing Manipulator Kinematics, Christopher Cook, T Vu-Dinh
New General Algorithm For Describing Manipulator Kinematics, Christopher Cook, T Vu-Dinh
Christopher Cook
A new algorithm for representing the kinematic problem of robot arms is presented, and its advantages discused. It is shown that manipulator links and joints can be described using generalised cascaded 'robot joint descriptors'. Such a description provides a theoretical basis for the development of a kinematic controller applicable to most manipulator geometries.
Characterisation And Control Of A Prototype Hts Smes Device, Christopher J. Hawley, Dominic Cuiuri, Christopher D. Cook, Steve Gower, Timothy Beales
Characterisation And Control Of A Prototype Hts Smes Device, Christopher J. Hawley, Dominic Cuiuri, Christopher D. Cook, Steve Gower, Timothy Beales
Christopher Cook
A 2.79 kJ prototype high transition temperature Superconducting Magnetic Energy Storage (SMES) device has been constructed. The coil for the prototype has been wound using High Temperature Superconducting (HTS) BSCCO-2223 tape. The refrigeration system is a gaseous helium cold head cryocooler used to maintain the SMES coil at a temperature of 30 K, improving the Ic characteristic of the coil by a factor of 4.7 compared to that at 77 K. The SMES device is capable of supplying a 3-phase load during power interruptions, and has been constructed during a program to develop a larger 20 kJ system aimed at …
Measurements Of Ac Losses In Htsc Wires Exposed To An Alternating Field Using Calorimetric Methods, Tri Hardono, Christopher Cook, Jian Xun Jin
Measurements Of Ac Losses In Htsc Wires Exposed To An Alternating Field Using Calorimetric Methods, Tri Hardono, Christopher Cook, Jian Xun Jin
Christopher Cook
Calorimetric methods for AC loss measurement for short superconducting wires have been investigated. The design, operation and results obtained from an experimental calorimeter are described. With these methods the total loss of a short superconducting sample exposed to a 50 Hz alternating field, both perpendicular and axial, have been measured with an accuracy of microwatts per centimeter. The sample is a 6 centimeter long (Bi,Pb)SrCaCuO-2223 silver-sheathed multifilamentary wire prepared by powder-in-tube techniques. The hysteresis part of the loss may be obtained by taking the eddy current component of the silver sheath from the total loss and by neglecting the coupling …
Magnetic Saturable Reactor Type Hts Fault Current Limiter For Electrical Application, Jian Xun Jin, S Dou, Christopher Cook, C Grantham, M Apperley, Timothy Beales
Magnetic Saturable Reactor Type Hts Fault Current Limiter For Electrical Application, Jian Xun Jin, S Dou, Christopher Cook, C Grantham, M Apperley, Timothy Beales
Christopher Cook
An electricalfaultcurrentlimiter (FCL) developed based on the principle of a magneticsaturablereactor requires a high current ampere-turn coil as its dc bias, and this coil is necessary to use a high temperature superconducting (HTS) winding. This HTS FCL has been studied, and identified with several advantages compared to other HTS FCLs, and therefore is further considered for its practical industry application.
Quartz Crystal Microbalance Study Of Volume Changes And Modulus Shift In Electrochemically Switched Polypyrrole, Mehrdad Bahrami-Samani, Christopher Cook, John Madden, Geoffrey Spinks, Philip Whitten
Quartz Crystal Microbalance Study Of Volume Changes And Modulus Shift In Electrochemically Switched Polypyrrole, Mehrdad Bahrami-Samani, Christopher Cook, John Madden, Geoffrey Spinks, Philip Whitten
Christopher Cook
The performance of conducting polymers as actuators is determined by a complicated series of molecular processes that occur as a result of oxidation and reduction of the polymer. In particular, the amount of actuation strain generated for a given voltage stimulus is determined by the number and type of ions (and solvent) that enter and leave the polymer and changes in the mechanical properties (particularly elastic modulus) of the polymer. In this paper, we present the effects of cyclic voltammetry on the shear modulus and volume of polypyrrole in two different electrolytes: propylene carbonate and an ionic liquid. An electrochemical …
Calorimetric Methods For Measuring Ac Losses In Htsc Tapes Carrying Currents, T Hardono, Christopher Cook, Jian Xun Jin
Calorimetric Methods For Measuring Ac Losses In Htsc Tapes Carrying Currents, T Hardono, Christopher Cook, Jian Xun Jin
Christopher Cook
Power engineering applications of HTSC tapes are often restricted by AC losses. Both direct and indirect methods have been used to measure AC losses in short samples. This paper reports on the development of a direct calorimetric method for AC loss measurement techniques for short tapes based on measurements of slight temperature increases of the sample. This method has the advantage of measuring total losses in the HTSC sample. The test rig discussed here consists of a calorimeter and associated data collection and analysis equipment. The calorimeter uses a sensitive temperature sensor and an ohmic heater, needed for the calibration …
A Monocular Approach To Depth Maps Generation, H Shi, Fazel Naghdy, Christopher Cook
A Monocular Approach To Depth Maps Generation, H Shi, Fazel Naghdy, Christopher Cook
Christopher Cook
In this paper, amonocularapproach for generation of the depthmaps of an object using computer vision is proposed. In this technique the object is immersed in a colour liquid and a single plan view is captured by a CCD camera. Due to the absorption property of the colour liquid, the intensity of the pixels of the captured image is modulated by the depths of the object along the camera axis. The depthmaps are generated from the grey level image by consecutive segmentation of the image into binary images at various thresholds. The depthmaps produced are parallel layers located in planes normal …
Drilling Of Carbon Composites Using A One Shot Drill Bit. Part 2 Empirical Modeling Of Maximum Thrust Force, Marta Fernandes, Christopher Cook
Drilling Of Carbon Composites Using A One Shot Drill Bit. Part 2 Empirical Modeling Of Maximum Thrust Force, Marta Fernandes, Christopher Cook
Christopher Cook
In order to extend tool life and improve quality of hole drilling in carboncomposite materials, a better understanding of ‘oneshot’ hole drilling is required. This paper describes the development of an empirical model of the maximum thrust force and torque produced during drilling of carbon fiber with a ‘oneshot’ drillbit. Shaw's simplified equations are adapted in order to accommodate for tool wear and used to predict maximum thrust force and torque in the drilling of carboncomposite with a ‘oneshot’ drillbit. The mathematical model is dependent on the number of holes drilled previously, the geometry of the drillbit, the feed used …
Inversion-Based Feedforward Control Of Polypyrrole Trilayer Bender Actuators, Stephen W. John, Gursel Alici, Christopher David Cook
Inversion-Based Feedforward Control Of Polypyrrole Trilayer Bender Actuators, Stephen W. John, Gursel Alici, Christopher David Cook
Christopher Cook
Conducting polymer bending actuators show potential for unique manipulation devices, particularly at the microscale, given low actuation voltages, controllable manufacture, biocompatibility, and ability to operate in either air or liquid environments; however, the impracticalities of implementing feedback in these environments and at these scales can impede positional control of the actuator. This paper presents an application of inversion-based feedforward positional control to a trilayer bender actuator, which is shown to improve the performance without the use of feedback or adjustments to the chemistry of the device. The step and dynamic displacement responses have all been improved under the feedforward control …
Dynamics Characteristics Of A Scara Robot Subject To Nc2 Velocity Trajectories With Different Payloads, M Ibrahim, Christopher Cook
Dynamics Characteristics Of A Scara Robot Subject To Nc2 Velocity Trajectories With Different Payloads, M Ibrahim, Christopher Cook
Christopher Cook
This paper presents a computer study that was conducted on the dynamics of arobot of aSCARA geometrical configuration. All links of this robot were moving in NC2 (Numerical Control 2) velocitytrajectories. The study was conducted to investigate the effect of payload variation on the gravitational (potential) as well as inertial and centripetal/coriolis (kinetic) forces. The results of these effects are discussed. All the simulation software was written in extended ANSI FORTRAN 77 and run on an HP 9000/550 computer using the UNIX operating system.
Novel Ac Loss Measurement Of High T C Superconducting Long Wire, Jian Xun Jin, S Dou, T Hardono, Christopher Cook
Novel Ac Loss Measurement Of High T C Superconducting Long Wire, Jian Xun Jin, S Dou, T Hardono, Christopher Cook
Christopher Cook
A novel method for AC loss measurement of a long length high Tc superconducting (HTSC) wire has been investigated. An 8 m long (Bi,Pb)2Sr2Ca2Cu3O10+x Ag clad multifilament wire was selected to prepare a special sample in which the inductive voltage induced by AC transport currents can be cancelled. Consequently the resistive voltage of the HTSC long wire can be measured. The HTSC sample has been tested at 77 K with AC transport currents up to 3Ic and at various frequencies from 10 Hz to 1 kHz. The loss of the (Bi,Pb)2Sr2Ca2Cu3O10+x Ag clad wire related to its zero field AC …
Critical Current Degradation Caused By Winding Process Of Bi-2223/Ag Hts Wire In The Form Of A Coil, Jian X. Jin, S X. Dou, Hua-Kun Liu, T Hardono, Christopher D. Cook, C. Grantham
Critical Current Degradation Caused By Winding Process Of Bi-2223/Ag Hts Wire In The Form Of A Coil, Jian X. Jin, S X. Dou, Hua-Kun Liu, T Hardono, Christopher D. Cook, C. Grantham
Christopher Cook
High T, superconducting (HTS) (Bi,Pb)2Sr2Ca2 Cu3010+xA g-clad wire has potential for practical applications in the form of a coil or a winding. This HTS wire has strong magnetic field-dependent and mechanical strain-dependent critical currents, consequently it faces a severe problem of critical current degradation when it is used in the form of a coil. To design a winding with this conductor, the critical current degradation has to be identified with relation to the magnetic fields and the winding process. This is important to optimize an appropriate coil winding procedure using this HTS wire. A specially designed non-inductive sample has been …
Design And Simulation Of Roadway Development Operations To Improve Productivity, Soumya Raghavendra Rao, Christopher D. Cook, Ernest Y. Baafi, R Porteous
Design And Simulation Of Roadway Development Operations To Improve Productivity, Soumya Raghavendra Rao, Christopher D. Cook, Ernest Y. Baafi, R Porteous
Christopher Cook
A typical Australian 3–5 Mt/year longwall requires 9 to 15 km of roadway to be developed every year (G. Lewis and G. Gibson: Proc. 13th Austr. Tunnelling Conf., Melbourne, Australia, May 2008, ATS, 317–326.). One of the major challenges faced by the Australian longwall mining industry is that roadway development has been unable to keep pace with improvements in longwall extraction rates. This has affected the profitability, viability and future of underground coal mines (M. Kelly: 'Coordination of roadway development strategy', ACARP report no. C5013, ACARP, Brisbane, Australia, 1997.). Gibson (G. Gibson: 'Australian roadway development– current practices', ACARP report no. …
Setting Up A Cim System For Training And Demonstration - On A Budget: The 'Acme Fms', Guenter Arndt, Christopher Cook, B Fowler
Setting Up A Cim System For Training And Demonstration - On A Budget: The 'Acme Fms', Guenter Arndt, Christopher Cook, B Fowler
Christopher Cook
The main aim of the paper is to pass on experience in setting up a CIM system for training and, demonstration on a restricted budget, in order to simulate real conditions in industry. The conclusions drawn are relevant to the restructuring of Australia's manufacturing industry, especially relating to Advanced Manufacturing. To begin with, a history of the project from concept to realisation is given, including participants involved, project objectives, and a description of the system. Hence the paper covers the manufacturing abilities of the ACME FMS, a section on integration and control aspects, a cost analysis, information on training directions, …
Results Of Ac Loss Tests On Twisted And Untwisted Htsc Tape Exposed To An External Field, T. Hardono, C. Cook, F. Darmann
Results Of Ac Loss Tests On Twisted And Untwisted Htsc Tape Exposed To An External Field, T. Hardono, C. Cook, F. Darmann
Christopher Cook
This paper presents the results of magnetic losstests on twisted and untwisted 37 multifilaments tapes exposed to an alternating field at power frequencies. The losses are measured using calorimetric methods, which are capable of measuring losses in short tapes with the accuracy of several microwatts per centimeter of tape. The losses of the tape due to the longitudinal field of the untwisted tape agree well with theoretical calculations. The measurement results on the twisted filament tape, with 50-mm twist pitch, show that the losses are slightly lower than that in the untwisted tape. This is due to the reduction of …
A Framework For Sharing Knowledge In Product Development By E-Collaboration Through Project Management, Marjan Mohammadjafari Dr, Shamsuddin Ahmed, Siti Zawiah Md, Hadi Zayandehroodi
A Framework For Sharing Knowledge In Product Development By E-Collaboration Through Project Management, Marjan Mohammadjafari Dr, Shamsuddin Ahmed, Siti Zawiah Md, Hadi Zayandehroodi
Dr. Marjan Mohammadjafari
In this study, the author has purposed electronic collaboration (E-collaboration) through a project manager between different departments in a factory can create a favorable environment to development the projects in terms of time and cost. In fact, the E-collaboration is a tool in hands of project managers. For this concept the author purposes, a conceptual model for sharing knowledge, which support development product. The model uses four factors, namely, design, planning, procurement and production. In addition, these factors consist of several items separately: For design department, there are four categories: (1) standard materials (2) teamwork (3) expected level of production …
The Importance Of Project Management In Smes For The Development Of New Products Through E-Collaboration, Marjan Mohammadjafari, Shamsuddin Ahmed, Siti Zawiah Md Dawal, Hadi Zayandehroodi
The Importance Of Project Management In Smes For The Development Of New Products Through E-Collaboration, Marjan Mohammadjafari, Shamsuddin Ahmed, Siti Zawiah Md Dawal, Hadi Zayandehroodi
Dr. Marjan Mohammadjafari
The research in this paper seeks ways for manufacturing companies to accomplish projects in real time with less cost. This paper describes a new model using critical success factors of implementing projects in small- and medium-sized enterprises (SMEs). The factors in the conceptual model were identified in past studies and are validated from interviews with 20 project managers in the electronics industry in Iran. Several prior researches have suggested critical success factors for reducing time and cost in the development of a new product. These factors are related to design, product, planning and procurement. However, none of these studies has …
Distributed Generator And Their Effects On Distribution System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari
Distributed Generator And Their Effects On Distribution System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari
Dr. Hadi Zayandehroodi
The connection of distributed generators (DGs) to distribution networks greatly influences the performance and stability of such networks. Though DGs have significant economic and environmental benefits, increased penetration of DGs will impose significant technical barriers for the efficient and effective operation of bulk power systems. Increased fault current contribution and load flow changes are the major two impacts on utility systems, and these will affect existing protective relaying, especially overcurrent relays. To ensure safe and selective protection relay coordination, the impact of DGs should be taken into account when planning DG interconnection. This paper presents an introduction of distributed generators …
Impact Of Distributed Generations On Power System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari
Impact Of Distributed Generations On Power System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari
Dr. Hadi Zayandehroodi
Though distributed generators (DGs) have significant economic and environmental benefits, increased penetration of DGs will impose significant technical barriers for the efficient and effective operation of bulk power systems. Increased fault current contribution and load flow changes are the major two impacts on utility systems, and these will affect existing protective relaying, especially overcurrent relays. To ensure safe and selective protection relay coordination, the impact of DGs should be taken into account when planning DG interconnection. This paper presents an introduction of DGs and an overview of the impacts of DGs on system protection relay coordination. Several protection issues are …
A Comprehensive Review Of Protection Coordination Methods In Power Distribution Systems In The Presence Of Dg, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari
A Comprehensive Review Of Protection Coordination Methods In Power Distribution Systems In The Presence Of Dg, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari
Dr. Hadi Zayandehroodi
This paper presents an overview of solutions proposed in the literature for the overcurrent relay coordination problem in the presence of distributed generators (DGs). Furthermore, several protection issues are identified to study the requirements for protection in the presence of DGs, and possible innovative solutions for resolving the operational conflicts between distribution networks and DGs are also discussed.
A Conceptual Model For Creating A Favorable Environment To Reduce The Production Time And Cost Of Production By E_Collaboration, Marjan Mohammadjafari, Shamsuddin Ahmed, Siti Zawiah Md Dawal, Hadi Zayandehroodi
A Conceptual Model For Creating A Favorable Environment To Reduce The Production Time And Cost Of Production By E_Collaboration, Marjan Mohammadjafari, Shamsuddin Ahmed, Siti Zawiah Md Dawal, Hadi Zayandehroodi
Dr. Marjan Mohammadjafari
The companies need to the implementation the projects on time within budget for achievement the success and competitive in the market. The prior researcher illustrated many method and model for development time in new product. For this purpose, in this research the author created a new model and allegation the electronic collaboration (E_collaboration) by a project manager can create a favorable environment to reduce the production time and cost of production of new product. This model is composed of four construct: design, planning, procurement and production. For initially evaluated the model the author has done interview with 20 project managers …
Reducing Time And Cost Of New Product Development In Smes By E-Collaboration Through Project Management Approach, Marjan Mohammadjafari, Shamsuddin Ahmed, Siti Zawiah Md Dawal, Hadi Zayandehroodi
Reducing Time And Cost Of New Product Development In Smes By E-Collaboration Through Project Management Approach, Marjan Mohammadjafari, Shamsuddin Ahmed, Siti Zawiah Md Dawal, Hadi Zayandehroodi
Dr. Marjan Mohammadjafari
One of the most serious bottlenecks in many small and medium enterprises (SMEs) is the long time required for new product development. Most SME manufacturing companies have realized that they cannot compete, unless they their shorten product development cycle times. At the same time, the rapid evolution of Web-based technologies and knowledge of project management has revolutionized the product development process. Through the literature review and real world insights, this paper proposes a conceptual model and a series of hypotheses. The model integrates departments of design, planning, production and procurement in the company via project management with electronic collaboration (E-collaboration) …
Toward A Theoretical Concept Of E-Collaboration Through Project Management In Smes For Reducing Time And Cost In New Product: A Review, Marjan Mohammadjafari, Siti Zawiah Md Dawa, Shamsuddin Ahmed, Hadi Zayandehroodi
Toward A Theoretical Concept Of E-Collaboration Through Project Management In Smes For Reducing Time And Cost In New Product: A Review, Marjan Mohammadjafari, Siti Zawiah Md Dawa, Shamsuddin Ahmed, Hadi Zayandehroodi
Dr. Marjan Mohammadjafari
Reducing time and efficient project execution is an objective in many industries and project management is one of the important keys for lead the company to this allegation. The project manager needs some tools for lead the firm to the success. Collaboration is one way to success and collaboration has many types, one kind is electronic collaboration. On the other hand, small and Medium Size Enterprises (SMEs) are a part of manufacturing industries. Combining a literature review with our empirical experience we found that relationship between the project manager and related departments for production is essential for reducing time and …