bluuebunny/crossref_metadata_2025 huggingface dataset:
MULTI-PHASE MOTION GENERATION OF FIVE-BAR MECHANISMS WITH PRESCRIBED RIGID-BODY TOLERANCES
Authors: MUSA MAJDI H. , RUSSELL KEVIN , SODHI RAJ S.
Published: April 2018

This work presents a technique for synthesizing adjustable planar, five-bar motion generators to approximate prescribed rigid-body positions and satisfy rigid-body positions with prescribed tolerances. This method is an extension of the adjustable planar five-bar motion generation method introduced by the authors (1). By incorporating rigid-body point tolerances in the rigid-body displacement matrices, the calculated circle and center point curves of the five-bar mechanism become circle and/or center point regions. From these regions, fixed and moving pivots for the five-bar mechanism can be selected that approximate the prescribed rigid-body positions and satisfy rigid-body positions with prescribed tolerances. The example in this work considers two-phase moving pivot adjustments in the planar five-bar motion generator.
PRELIMINARY DESIGN OF A KNEE EXTERNAL FIXATOR BASED ON PLANAR GEOMETRIC SYNTHESIS
Authors: Fragomeni G. , Mundo D. , Gatti G. , Moschetta D. , Danieli G.A.
Published: April 2018

The paper presents the validation of a methodology for the optimal synthesis of a planar mechanical system able to reproduce knee kinematics in a limited range of motion. Such a mechanism could be effectively used in the design and placement of a moving external fixator for the knee joint articulation in either post-traumatic and pathological treatment or rehabilitation. The purpose is to help patient’s recovery through a limited and occasional movement of the articulation without loading the injured area.

In order to validate the actual method, knee kinematics is estimated by means of plane radiographs of the articular joint of an healthy volunteer at different flexion angles. Each of the lateral radiographs shows the relative tibia-femur motion in different configurations. The whole movement is reconstructed by interpolation, assuming a relative gliding law.

Geometric synthesis, based on Burmester’s theory, is thus used to identify a set of compatible four-bar-linkages (f.b.l.), which reproduce the estimated rigid body motion.
A LOW COST MACRO-MICRO POSITIONING SYSTEM WITH SMA-ACTUATED MICRO STAGE
Authors: Ho Eric , Gorbet Rob
Published: April 2018

Macro-micro systems allow high-resolution positioning over greater ranges of operation that would be achievable with precision positioning systems. Piezoceramic actuators have established themselves as the principle technology for commercial micro-positioning applications, and the trend in research is to push the limits of resolution down to the nanometer and sub-nanometer scales. Other smart materials offer the potential for lightweight, continuous actuation over small ranges, and hence may be useful in micro-positioning applications. This work focuses on the potential for SMA actuators to enable low-cost micro-positioning. Compared to piezos, SMA offer longer range and lower actuation voltages, enabling lower-cost drive electronics and removing the need for costly precision mechanical amplification stages. A prototype single-axis macro-micro positioning system is described, with a macro range of 200 mm and relative positioning precision of better than 5 5μm. The micro stage is driven by an NM70 SMA actuator from NanoMuscle. Macro and micro stages are modelled and controllers developed, and experimental system performance is evaluated. The success of the system provides an inexpensive platform for the study of macro-micro positioning issues such as stage coupling, friction, and drive flexibility, as well as for the position control of SMA.
NEURAL MODELING AND CONTROL OF DYNAMIC SYSTEMS WITH HYSTERESIS
Authors: Tan Yonghong , Zhao Xinlong
Published: April 2018

A hysteretic operator is proposed to set up an expanded input space so as to transform the multi-valued mapping of hysteresis to a one-to-one mapping so that the neural networks can be applied to model of the behavior of hysteresis. Based on the proposed neural modeling strategy for hysteresis, a pseudo control scheme is developed to handle the control of nonlinear dynamic systems with hysteresis. A neural estimator is constructed to predict the system residual so that it avoids constructing the inverse model of hysteresis. Thus, the control strategy can be used for the case where the output of hysteresis is unmeasurable directly. Then, the corresponding adaptive control strategy is presented. The application of the novel modeling approach to hysteresis in a piezoelectric actuator is illustrated. Then a numerical example of using the proposed control strategy for a nonlinear system with hysteresis is presented.
FLEXIBLE STAB RESISTANT CERAMIC-BASED BODY ARMOUR
Authors: Croitoro Elena M. , Boros I. Eugen
Published: April 2018

This paper presents the results of a study on performance of flexible stab resistant ceramic-based composite body armour that our research group has initiated, designed, assembled, and tested. The test outcomes were characterized in terms of the kinetic energy of the stabbing weapon at impact and the depth of penetration of the stab into the armour. A neutral date fitting model that departs from the classical least square approach is proposed. The test results show that the flexible panels are especially suitable for medium and low protection levels and by comparison with rigid panels, the flexible panels allow a deeper penetration which increases with thrust energy.
A REVIEW OF FORMULAE FOR AVERAGING PHYSICAL QUANTITIES (APPLICATION TO CALCULATION OF THE AVERAGE RADIUS OF TUBES)
Authors: Stepanov I. A.
Published: April 2018

A new method for averaging physical quantities is discovered. It is shown that the traditional method of finding the average value of a physical quantity gives the wrong results when calculating the average radius of a tapering tube, the average flow velocity in the tube and the volume of liquid flow through the tapering tube. The new method of averaging gives the correct results. The new formula is applicable to many other processes, for example, for calculating the flow through tubes of arbitrary form or with time-dependent radius. At present, a neutral radius is used which leads to big discrepancies.
KINEMATIC AND DYNAMIC ANALYSIS OF A SPATIAL ONE-DOF FOLDABLE TENSEGRITY MECHANISM
Authors: SWARTZ M. A. , HAYES M.J.D.
Published: April 2018

This paper presents a mechanical analysis of a spatial 1-DOF tensegrity mechanism created by connecting three planar tensegrity mechanisms to form a triangular prism. The subsequent investigation produced kinematic and dynamic models that allow the workspace-boundary singularities and minimum energy configuration to be determined. Singularities were found to occur when the mechanism is folded in the vertical X, Y plane or in the horizontal X, Z plane. The minimum energy configuration, formed by the angle between the horizontal plane and the actuated strut, was found to be θ = π/4. However, when the system was linearized to determine the analytic solution for the dynamics, the minimum energy configuration become θ = 1 due to the inherent error produced by the system linearization. The dynamic response of the mechanism to an initial small displacement was determined for each case of critically damped, overdamped, and underdamped systems.
HYDRAULIC BEHAVIOUR OF UNCONVENTIONAL RADIAL PUMP STAGES
Authors: Gantar Tine , Sekavcnik Mihael
Published: April 2018

This paper investigates the hydraulic behaviour of unconventional radial pump stages observed utilizing the CFD analyses. The main emphasis was put on the influence of radial pump stage (RPS) geometry on the basic flow direction in the pump regime. In order to preclude defining the flow direction as a boundary condition, a closed hydraulic system was modelled to investigate the hydraulic behaviour of the RPS and its energy characteristics. It was confirmed that centripetal flow through the RPS is possible in the pump regime, but not without the installation of an appropriate stator on the inner rotor radius. The influence of the inner rotor radius stator geometry on the basic flow direction in the pump regime is discussed. The manner of the operation type switching between centripetal and centrifugal pumping achieved with the variation of the hydraulic losses within the closed hydraulic system is explained. In addition to the closed hydraulic system calculations used for investigation of the RPS operation in the pump regime, the open hydraulic system was modelled to determine the energy characteristics of the analysed radial pump stages in other operating regimes. All operating regimes of the important RPS cases are presented by means of four-quadrant charts.
MICROSTRUCTURAL MODELING OF COLD CREEP/FATIGUE IN NEAR ALPHA TITANIUM ALLOYS USING CELLULAR AUTOMATA METHOD
Authors: Boutana N. , Bocher P. , Jahazi M. , Piot D. , Montheillet F.
Published: April 2018

It is well known that the presence of large heterogeneous textured regions in forged near alpha titanium alloys could lead to large variations of mechanical properties when fatigue and creep cycles are applied at room temperature. On the other hand, experimental studies and microtexture investigations are complex to set up, lengthy and costly, and one cannot expect to understand the alloy behavior by relying only on empirical approaches. Hence, numerical methods are excellent alternatives for analyzing the influence of microscopic and macroscopic heterogeneities on mechanical properties in shorter times and with minimum need for experimentation. In the present investigation, a cellular automata (CA) method was used to simulate the effect of texture heterogeneities, on both local and global mechanical properties. A 2D array of cells was used and the stresses and strains developed in various heterogeneous regions were evaluated using the Eshelby theory. Using the CA method, various types of microstructures were modeled and compared with each other to quantify the influence of processing parameters on mechanical properties. The results predict, and are used to explain, the experimentally phenomena observed in creep responses during cold fatigue/creep tests of near alpha titanium samples.
EFFECTS OF BRAKE DISC GEOMETRICAL PARAMETERS AND CONFIGURATIONS ON AUTOMOTIVE BRAKING THERMAL PERFORMACE
Authors: Chi Zhongzhe , Naterer Greg F. , He Yuping
Published: April 2018

This paper examines the effects of geometrical parameters of pillar post rotors on the thermal performance of automotive vehicle brakes. The thermal performance of vented disc brakes strongly depends on the aerodynamic characteristics of the air flow through the rotor passages. These air flow passages are determined by the geometrical parameters of the brake rotors. In this study, different pillar post rotor models are considered and the corresponding numerical simulations are performed, in order to investigate the effects of various geometrical parameters on the thermal performance. These geometrical parameters include the shape, size, and distribution of a pillar post. The new insight from these parametric studies provides useful guidelines to optimize the geometry of pillar post rotors of automotive vehicles.
THE BIAS TEMPERATURE DEPENDENCE ESTIMATION AND COMPENSATION FOR AN ACCELEROMETER BY USE OF THE NEURO-FUZZY TECHNIQUES
Authors: Grigorie Lucian Teodor , Botez Ruxandra Mihaela
Published: April 2018

In this paper, we describe a new method for improved performance of inertial sensors, with applications in strap-down inertial systems. A new empirical model is proposed for the bias temperature dependence compensation of accelerometers using their input and output data. Experimental testing of the accelerometer is first realized, as data for 2 inputs and 1 output are collected. Based on this data, an empirical model is built using a neuro-fuzzy network, which learns the process behavior and uses a Fuzzy Inference System (FIS) for model realization. The improvement in the reproduction quality of the experimental surface by the neuro-fuzzy model is achieved through the FIS training using a Sugeno learning algorithm with two inputs and one output. Generation and training of the FIS are performed with Matlab functions, the training of which is realized on a high number of epochs, for example, on a number of 105 training epochs. It is noticed that the proposed algorithm leads to a 35.5 times reduction in the error due to temperature dependence of the bias.
OPTIMAL NOISE CONTROL ON PLANT USING SIMULATED ANNEALING
Authors: Lan Tian-Syung , Chiu Min-Chie
Published: April 2018

Noise control is important and essential in a manufacturing factory, where the noise level is restricted by the Occupational Safety and Health Act. Several researches on new techniques of single noise control have been well addressed and developed; however, the study of noise depression on the whole plant noise by using optimum allocation planning is hardly found. An improper machine allocation will not only result in the tremendous cost on noise control task, but also cause the harmful environment for the neighborhood; therefore, the approach of optimum and economic allocation of noise sources within a constrained plant area becomes crucial and obligatory.

In this paper, a novel technique of simulated annealing (SA) is applied in the numerical optimization, and the multi-noise plant with various sound monitoring systems is also introduced. Before optimization, the single noise is tested and compared with the simulated data from SoundPlan, a commercial sound simulation package, for the accuracy check of the mathematical model. The result reveals to be within good agreements. The proposed SA optimization on the allocation of multi-noise plant surely provides an economic and effective methodology in reducing the sound accumulation around the plant boundary.
PERFORMANCE EVALUATION OF COUNTER-FLOW WET COOLING TOWERS USING EXERGETIC ANALYSIS
Authors: Ataei A. , Panjeshahi M. H. , Gharaie M.
Published: April 2018

In this paper, performance evaluation of wet cooling tower is done. To achieve this aim, first, thermal behavior of counter-flow wet cooling tower is studied through a simulation model. The influence of the environmental conditions on the thermal efficiency of the cooling tower is investigated. The cooling tower performance is simulated in terms of varying air and water temperatures, and of the ambient conditions. This model allows the use of a variety of packing materials. Second, the exergetic analysis is applied to study the cooling tower potential of performance improvement. The model is validated against the experimental data.
GUEST EDITORIAL: INTRODUCTION TO THE SPECIAL ISSUE ON SUSTAINABLE ENERGY SYSTEMS
Authors: Rosen Marc A. , Reddy Bale V. , Dincer Ibrahim
Published: April 2018

not available
HOURLY EMISSION FACTORS FROM THE ELECTRICITY GENERATION SECTOR – A TOOL FOR ANALYZING THE IMPACT OF RENEWABLE TECHNOLOGIES IN ONTARIO
Authors: Gordon Christian , Fung Alan
Published: April 2018

In this research, seasonal greenhouse gas (GHG) emission factors were developed to realize the true CO2 reduction potential of a small scale renewable energy technology. From this data Time Dependent Valuation (TDV) emission factors and hourly emission factors were developed which provided upper and lower limits, respectively. The use of regionally specific climate-modeled factors, such as those identified, allowed for a better representation of the benefits associated with GHG reducing technologies, such as photovoltaic (PV)
SKEW RAY TRACING AND ERROR ANALYSIS OF OPTICAL LENS WITH CYLINDRICAL BOUNDARY SURFACE
Authors: Liao Te-Tan , Chen Shih-Hung , Chen Kuo-Ying , Chen Chun-Ta
Published: April 2018

This study applies computational geometric algebra based on a 4 × 4 homogeneous transformation matrix and Snell’s law of geometrical optics to analyze skew rays and the errors of a light ray’s path as it passes through a cylindrical lens. The author addresses two important topics: (1) the determination of the direction of a reflected or refracted ray by Snell’s law and (2) the expression of the combination of two principal sources of light path error using error analysis. In topic (2), one of the sources is the translational errors Δdix, Δdiy, and Δdiz and the rotational errors Δωix, Δωiy, and Aωiz that determine the deviation of the light path at each boundary surface, while the other source is the differential changes induced in the incident point position and the unit directional vector of the refracted/reflected ray as a result of differential changes in the position and unit directional vector of the light source. The methodology presented in this study provides a comprehensive and robust approach for evaluating the error of a light ray path as it passes through a cylindrical lens.
WORM COIL DISTRIBUTION AND LOAD-CARRYING ABILITY FOR AN ELECTROMECHANICAL INTEGRATED TOROIDAL DRIVE
Authors: Xu Lizhong , Zheng Dazhou
Published: April 2018

This paper investigates worm coil distribution and load-carrying ability for a toroidal drive. The lead angle equations for the worm groove are given for different coil distributions. The center curve of the worm groove is obtained using coordinate transformation. A 3D worm model is constructed using Pro/Engineer software and the average output torque is presented to compare load-carrying ability for the drive with different worm coil distributions. As the number of the planet teeth increases, the output torque of the drive first increases then decreases. Large output torque requires an optimum number of planet teeth and a larger number of pole pairs and stator teeth.
AN AUTOPILOT DESIGN FOR THE LONGITUDINAL DYNAMICS OF A LOW-SPEED EXPERIMENTAL UAV USING TWO-TIME-SCALE CASCADE DECOMPOSITION
Authors: Shiau Jaw-Kuen , Ma Der-Ming
Published: April 2018

This paper discusses a cascade decomposition method for two-time-scale systems. We decompose the two-time-scale system into slow and fast subsystems connected in cascade form. With the proposed decomposition method, fast and slow low-order subsystems can be easily extracted from the two-time-scale full order system. The longitudinal dynamics of a low speed experimental UAV is used to illustrate the proposed method. An altitude hold control structure is constructed to allow sequential designs based on the lower order fast and slow models using classical designs. The structure contains two control loops. The inner loop is for altitude rate regulation. In this control loop, we use combination of altitude rate and pitch angle as the feedback signals. A fast controller is designed to satisfy the high frequency requirements using the fast model. Following the results of the fast design, three control gains are designed to satisfy the low frequency requirements using the slow models. The design results of the inner loop are used to design the outer altitude control loop. Frequency domain analysis and computer simulations confirm the success of the proposed decomposition method and verify the effectiveness of the control law using the proposed control structure.
KINEMATIC ANALYSIS AND PERFORMANCE EVALUATION OF 6R INSTRUMENTED SPATIAL LINKAGES
Authors: Gatti Gianluca , Mundo Domenico , Danieli Guido
Published: April 2018

Six-degree-of-freedom instrumented spatial linkages are often used to measure anatomical joint motion for clinical studies or research applications in biomechanics. Their appropriate design is a fundamental issue to allow for accurate measurements and ease of application, and this mainly relies on addressing the kinematic analysis of the linkage. The aim of this paper is to integrate and extend past literature in the field by giving a generalized set of guidelines and ready-to-use mathematical relationships to approach the whole kinematic analysis of a general instrumented spatial linkage in a systematic way. The direct kinematics is formulated using common robotics formulation and, with reference to a specific linkage architecture, a geometrical approach is proposed to solve for the inverse kinematics in closed-form. Kinematic error analysis is addressed in a generalized way by using differential transformation theory, and it is then applied to the specific case under study. By the proper definition of a virtual joint, the inverse kinematics is used to estimate the static performance of the linkage over its specific task space.
MULTI-MODE VIBRATION CONTROL AND POSITION ERROR ANALYSIS OF PARALLEL MANIPULATOR WITH MULTIPLE FLEXIBLE LINKS
Authors: Zhang Xuping , Mills James K. , Cleghorn William L.
Published: April 2018

This paper presents multi-mode vibration control and analysis of moving platform position errors of a planar 3-PRR parallel manipulator with three flexible intermediate links using PZT transducers. The active vibration controller is designed in modal space with modal filters and modal synthesizers determined from the flexible link vibration characteristics. Estimation of the moving platform position error is conducted using measurements of the flexible link deflection from PZT sensors mounted on the flexible intermediate links. An effective strategy for determining the control gains to reduce the vibrations of higher order modes is proposed through modification of the independent modal space control (IMSC) method. The proposed independent modal control strategy is experimentally implemented with first two modes targeted for control on a parallel manipulator with multiple flexible links. The experimental results show that the vibrations of the first two modes are effectively suppressed, and the position error of the moving platform is substantially reduced.
NONLINEAR VIBRATION OF A THREE-DIMENSIONAL MOVING GANTRY CRANE SUBJECTED TO A TRAVELLING TROLLEY HOISTING A SWINGING OBJECT
Authors: Younesian Davood , Ghafoori Elyas , Sadeghpour Mehdi
Published: April 2018

Nonlinear vibration of a three-dimensional moving gantry crane carrying a trolley hoisting a swinging object is studied in this paper. A finite element method is used to solve nonlinear coupled governing equations of the structure. A combinational technique (Newmark-Runge-Kutta) is employed for direct integration procedure. To develop a comprehensive parametric study and sensitivity analysis of the coupled nonlinear system, sequence of numerical simulations are carried out. Parametric study is directed to find out how different parameters like speed and acceleration of the trolley and gantry crane as well as the mass of the moving trolley and swinging object may affect the linear and nonlinear responses of the structure. It is found that the nonlinearity arises from large amplitude of three-dimensional motion of the swinging object.
ASYMPTOTIC ANALYSIS SOOT MODEL FOR A HIGH PRESSURE COMMON RAIL DIESEL ENGINE
Authors: Qiu Tao , Qi Zhiquan , Yin Wenhui , Liu Yongfeng
Published: April 2018

A TP (Temperature Phase) model is presented to carry out optimization calculation for a high-pressure common rail diesel engine. Temperature is the most important parameter in the TP model. When zone temperature T<1500 K, only the soot precursors –PAHs (Polycyclic aromatic hydrocarbons) is created and there is no soot emission. When zone temperature T≥1500 K, PAHs and soot source terms (particle inception, surface growth, oxidation, coagulation) are calculated. The TP model is then implemented in KIVA code instead of original model to carry out optimizing. The results of cylinder pressures, the corresponding heat release rates, and soot with variation of injection time, variation of rail pressure and variation of speed among TP model, KIVA standard model and experimental data are analyzed. The results indicate that the TP model can carry out optimization and CFD (computational fluid dynamics) and can be a tool to calculate for a high-pressure common rail diesel engine.
PERFORMANCE EVALUATION AND WAKE STUDY OF A MICRO WIND TURBINE
Authors: Comyn Graeme I. , Nobes David S. , Fleck Brian A.
Published: April 2018

In preparation for a study on icing of wind turbine blades, we tested a horizontal axis micro wind turbine in a low speed wind tunnel. The ratio of wind turbine rotor area to wind tunnel cross-sectional area resulted in highly blocked experimental configuration. The turbine was instrumented to measure rotational speed of the rotor, axial thrust and power output. Performance characteristics were calculated and compared with the manufacturer’s published data. In addition, the near wake of the turbine was measured with a Kiel probe. One dimensional axial momentum theory, including a modification that includes channel walls, was applied to determine power extracted from the wind by the rotor. The results were compared to actual power output and show that though the assumptions of the model over-predict power by 50 % the basic trend is followed.
HYDRAULIC DESIGN AND ANALYSIS OF THE SAXO-TYPE VERTICAL AXIAL TURBINE
Authors: Höfler Edvard , Gale Janez , Bergant Anton
Published: April 2018

The paper presents a procedure for hydraulic design and analysis of the blade geometry of a high specific speed runner of the Saxo-type double-regulated vertical axial turbine. The meridional through-flow in the passage from the conical guide vane apparatus to the draft-tube elbow is designed by a streamline curvature method (SCM). To validate the design method and predictions and to investigate the design duty point and a number of off-design operating regimes, an extensive CFD simulation inside the entire turbine water-passage is performed. The flow patterns downstream the guide vane apparatus and the runner exit flow are analyzed. The focus of the analysis is on distribution of the angular momentum alongside the turbine, as well as on its impact on the flow around the runner blades. The SCM design procedure presented in the paper proves to be a robust and accurate tool for the runner blade row design.
APPROACHES TO NON-CONTACT ANTERIOR CRUCIATE LIGAMENT INJURY STUDIES: UTILITY OF OPERATIONS RESEARCH AND ARTIFICIAL INTELLIGENCE
Authors: Ali Nicholas , Rouhi Gholamreza , Robertson Gordon
Published: April 2018

A multidisciplinary design optimization (MDO) approach is proposed to aid in the prediction of non-contact anterior cruciate ligament (ACL) injury mechanisms and risk factors. In this investigation the need for such an approach is argued based on an exhaustive evaluation of diverse factors that cause non-contact ACL injury, and the similarly numerous and different existing study approaches that have been carried out to investigate injury. The proposed MDO approach fuses patient data and existing study approaches via an artificial intelligent (AI) technique—absent in previous biomechanics investigations—so as to offer new insights into ACL injury prevention.
LENGTH-OPTIMIZED SMOOTH OBSTACLE AVOIDANCE FOR ROBOTIC MANIPULATORS
Authors: Parsa Soheil S. , Carretero Juan A. , Boudreau Roger
Published: April 2018

This paper presents a novel optimized smooth obstacle avoidance algorithm for robotic manipulators. First, a 3-4-5 interpolating polynomial is used to plan a smooth trajectory between initial and final positions in the joint space without considering any obstacles. Then, a simple harmonic function, which is smooth and continuous in displacement, velocity and acceleration, is applied to generate a new smooth path avoiding collisions between the robot links and an obstacle. The obstacle avoidance portions on the path are optimized such that the length of the path traversed by the end-effector is minimized. Simulation results for a 6 DOF serial manipulator demonstrate the efficiency of the proposed method.
AN APPROACH FOR COUNTING THE NUMBER OF SPECIALIZED MECHANISMS SUBJECT TO NON-ADJACENCY CONSTRAINTS
Authors: Hwang Yii-Wen , Wu Chiu-Chin , Lin Shu-Hong
Published: April 2018

This paper presents an improved approach to count the number of specialized mechanisms subject to non-adjacency constraints from a candidate kinematic chain. First, the permutation group of the candidate kinematic chain is found. Next, an inventory polynomial named kinematic king polynomial (KKP) to count the specialized mechanisms is modified from the traditional king polynomial related to the count of moves of a king on a chess. Then, an algorithm to calculate the KKP is presented by operations on labeled joint adjacency matrix (LJAM). Finally, two examples are illustrated to verify the approach.
THE DYNAMIC ANALYSES AND VERIFICATIONS OF A HOLLOW SHAFT WITH HOT-FIT COMPONENT USING 3D FINITE CONTACT ELEMENT
Authors: Chen Shin-Yong
Published: April 2018

In general engineering practice, one key factor in designing a motor built-in high-speed spindle is to assemble the motor rotor and shaft by means of hot-fit to form a new rotor-shaft assembly. In this paper, the dynamic analysis of a hot-fit rotor in a rotor-shaft assembly by using 3D contact element is proposed. Contact pressure between the rotor and the shaft is firstly calculated through contact theory. The stress state is thus determined. The finite element modal analysis then follows with the stress state as a pre-stressed condition. The accuracy and the validity of the finite contact element results are verified by theoretical formulation, equivalent static analysis and experimental modal testing. The results presented herein indicate that it is accurate and effective in analyzing the dynamic behavior of the rotary shaft system with a hot-fit component by using contact element.
OPTIMUM SYNTHESIS OF PATH GENERATING ADJUSTABLE MECHANISMS WITH IMPROVED SLOPE CONTINUITY OF THE CONTROL PARAMETER
Authors: Raste Hrishikesh Y. , Apte Ameya P. , Gogate Gunesh R.
Published: April 2018

Adjustable mechanisms have been studied in literature for path and function generation. In this paper, a path generating four-bar mechanism with an alternate single parameter adjustment is proposed and optimally synthesized, using the method of Differential Evolution. Two new approaches are developed, aimed at improving the slope continuity characteristic of the control parameter. Optimum synthesis results are obtained using the proposed approaches. The results show that the proposed approaches lead to improved slope continuity characteristics of the control parameter.
GROWTH CHARACTERISTICS AND PROPERTIES OF AL-DOPED ZnO THIN FILMS BY DC MAGNETRON SPUTTERING FROM AZOY® TARGET
Authors: Yao Pin-Chuan , Hang Shih-Tse , Wu Menq-Jiun
Published: April 2018

Transparent conducting Al-doped ZnO (AZO) thin films were deposited on soda-lime glass substrates by DC magnetron sputtering with a novel sintered ceramic target, AZOY® that contains a small amount of Y2O3 in addition to Al2O3 and ZnO. The effect of substrate temperature (Ts) on the structural, electrical and optical properties of the prepared AZO films was evaluated extensively. By elevating Ts, both the electrical conductivity and optical transmittance in the Vis/NIR region of the film could be effectively improved. The substrate heating is closely related to the crystallinity and the surface morphology of the deposited films. It is noteworthy that by employing this target material, high quality AZO thin films could be deposited with a simple and cost effective DC magnetron sputtering system.
THE MECHANICAL BEHAVIOUR OF COBALT SUPERALLOYS WITH TI ELEMENT ADDITION
Authors: Chen Tao-Hsing
Published: April 2018

The influence of titanium element, strain rate and tested temperatures on the mechanical properties and microstructural characteristics will be investigated in this paper. These cobalt-based superalloys are tested using material testing system (MTS) at strain rates of 10−3, 10−2 and 10−1 s−1 and at temperatures of 700, 500 and 25° C, respectively. It is found that the flow stress increases with increasing strain rate and Ti, but decreases with increasing temperature. Furthermore, the strain rate sensitivity increases with increasing strain rate, but decreases with increasing temperature. The microstructural observations confirm that the mechanical response of the cobalt superalloy specimens is directly related to the effects of the titanium contents, strain rate and temperature on the evolution of the microstructure. It can be observed that the strengthening effect in cobalt-based superalloys is a result primarily of dislocation multiplication. The dislocation density increases with increasing strain rate, but decreases with increasing temperature.
PERFORMANCE ANALYSIS OF SEVERAL QUASI-ORTHOGONAL CODES OPTICAL CDMA FOR RADIO-OVER-FIBER SYSTEM
Authors: Yen Chih-Ta , Ding Ing-Jr , Tsai Cheng-Mu
Published: April 2018

An optical code-division multiple-access (OCDMA) network for radio-over-fiber (RoF) transmissions was proposed. The network encoders/decoders (codecs) were structured based on arrayed-waveguide-grating (AWG) routers coded using modified prime codes (MPCs). In the proposed system, the lower in-phase cross correlation could reduce the beating noise, and in the proposed study, its performance was compared with that of a conventional system that uses M-sequence and Walsh-Hadamard codes. The performance of both systems was numerically evaluated by analyzing the effect of phase-induced-intensity noise (PIIN). The results showed that the new code families that had lower cross correlation can suppress the intensity of the noise and effectively cancel out the multiple-access interference (MAI) in balanced detection processes, which improved system performance. By using the proposed MPC-coded OCDMA ROF network codecs, each network required only two AWG routers to accomplish the spectral coding of radio base stations (RBSs) and the decoding of control stations (CSs), resulting in a simple and low-cost system. Therefore, it is possible to produce interference- and crosstalk-free optical CDMA systems for RoF transmissions.
DEVELOPMENT OF A LASER MEASUREMENT SYSTEM FOR FLATNESS AND THICKNESS OF THE RUBBER AND RACKET
Authors: Chen Yu-Fen , Liu Chien-Hung , Fang Te-Hua , Huang Chen-Chih , Liu Chi-Fan
Published: April 2018

This study analyzes the flatness of the commercial rackets measured by the modified S500 rubber thickness gauge mounted on a moving stage. A least square fitting method was used to calculate the racket flatness of these rackets. The experimental results showed the average flatness of all samples is 0.03 mm and the triple standard deviation is ±0.03 mm. The flatness of the rackets will lead to an in accurate examination of the rubber thickness before a match.
CONSTRUCTION OF AN ELEMENTARY MODEL FOR THE DYNAMIC ANALYIS OF A PRESSURIZED WATER REACTOR
Authors: Tsai Chiung-Wen , Shih Chunkuan , Wang Jong-Rong
Published: April 2018

A lumped-parameter numerical model was constructed based on the conservation laws of mass and energy and the point neutron kinetics with 6 groups of delayed neutron to represent the dynamics of a pressurized water reactor core. On the viewpoint of control theory, the coupled phenomenon of neutron kinetics and thermal-hydraulics can be recognized as a dynamic system with feedback loops by the Doppler effect and the coolant temperature. Scilab was implemented to construct the equivalent transfer functions and associated feedback loops of a PWR core. The dynamic responses were performed by the perturbations of positive reactivity insertion, coolant flow rate, and coolant inlet temperature. This elementary PWR core model has been qualitatively assessed against independent numerical data to ensure the models and codes have a certain level of confidence or validation.
GEAR FAULT DIAGNOSIS IN TIME DOMAINS VIA BAYESIAN NETWORKS
Authors: Wang Chun-Chieh , Kang Yuan , Liao Chin-Chi
Published: April 2018

In gear or rolling bearing systems, it is difficult to extract symptoms from vibration signals where shock vibration signals are present. However, the neural network method cannot provide satisfactory diagnosis results without adequate training samples. Bayesian networks provide an effective approach for fault diagnosis in cases given uncertain and incomplete information. In this study, the statistical factors of vibration signals in the time-domain were used and the diagnosis results by using Bayesian networks were superior to other neural network methods.
PASSIVITY-BASED INTEGRAL CONTROL AND STABILITY ANALYSIS OF A CONSTRAINED SINGLE-LINK FLEXIBLE ARM
Authors: Liu Liang Y. , Lin Hsiung C.
Published: April 2018

The design of flexible manipulator is complicated due to inherently infinite dimension in nature. The sequential challenge is the problem such a non-minimum phase that is the cause of system instability. In this paper, a constrained single-link flexible arm is fully investigated using a linear distributed parameter model. In order to overcome the inherent limitations, a new input induced by the joint angular acceleration and an output generated using the contact force and root shear force are defined. A necessary and sufficient condition is thus derived so that all poles and zeros of the new transfer function lie on the imaginary axis. Also, the passive integral control is designed to accomplish the regulation of the contact force. The excellent performance of the passive integral controller is verified through numerical simulations.
ON THE DESIGN OF NEW PROGRAMMABLE EXACT PATH GENERATORS
Authors: Soong Ren-Chung
Published: April 2018

A design method of new programmable exact path generators is proposed. The instantaneous positions of the linear input link corresponding to current angular positions of the rotational input link for each point of exact paths are also derived. By controlling the instantaneous position of linear and rotational input link, the required exact paths can be generated during a cycle. This design approach makes the proposed linkage mechanism programmable and adjustable, and increases their flexibility in practical applications.
COMBINED TEMPERATURE AND MOISTURE EFFECT ON THE STRENGTH OF CARBON NANOTUBE REINFORCED EPOXY MATERIALS
Authors: Jen Yi-Ming , Huang Chien-Yang
Published: April 2018

This study experimentally analyzed the hygrothermal effect on the static and fatigue strengths of multiwalled carbon nanotubes (CNTs)/epoxy composites. The results show that the static and fatigue strengths decreased slightly at 25°C/85% RH environments compared with those tested under the 25°C/60% RH condition. However, the strengths decreased substantially under the 40°C/85% RH condition, indicating that the combined temperature and humidity environments weaken the interfacial adhesion between the CNT surfaces and the epoxy matrix.
SUM OF SINUSOIDAL PLUS NOISE MODEL TO EXTRACT COMPONENT ERROR FROM A DOUBLE BALLBAR MEASUREMENT ERROR MAP
Authors: Saragih Agung-Shamsuddin , Ko Tae-Jo
Published: April 2018

The double ballbar (DBB) test, which captures actual data from multiple error origins of axes interaction, was defined as sinusoid error map model plus noise. When the number of sinusoids is the same as the number of individual errors of moving axis in the test map, we can extract a single source geometric error value from the DBB error map by modeling the well-known geometric error of linear axis. We considered the “noise” as mixed errors from other sources than geometric errors. This method is applicable to both a full circle and a truncated DBB test path.
TECHNICAL DEVELOPMENT OF HEAT ENERGY RECOVERY FOR VEHICLE POWER SYSTEM
Authors: Jeng Tzer-Ming , Tzeng Sheng-Chung
Published: April 2018

A Toyota 2200 c.c. vehicle with four-cylinder four-cycle engine was used for real vehicle test to discuss the influence of the vehicle’s engine speed and external cooling air flow on the energy output of the waste heat recovering thermoelectric conversion system. This study found that the energy output increased with the engine speed. However, if the engine speed was too high (exceeding 2500 rpm), the thermoelectric generator would be overheated and damaged. Besides, there was an optimal external cooling air flow to generate the maximum energy output.
SIMULATION OF THE STATIC INFLATION OF THE PASSIVE LEFT VENTRICLE TO AN END-DIASTOLIC STATE
Authors: Doyle Matthew G. , Tavoularis Stavros , Bougault Yves
Published: April 2018

To initiate our simulations of canine left ventricle (LV) mechanics, we needed to specify an initial geometry and an initial wall stress distribution. Although there are sufficient measurements of LV geometries, there are no assessments of stresses under any conditions. To estimate a physiologically plausible range of stresses at end diastole, we have inflated an unloaded reference geometry using static pressure loads. The LV was modelled as a six-layered truncated prolate ellipsoid. The myocardium was defined as a slightly compressible, transversely isotropic, hyperelastic material. The reference LV was inflated statically by gradually increasing the pressure on its inner surface until an end-diastolic state was reached. The calculated dependence of normalized LV volume changes on the applied pressure was in good agreement with previous experimental results. Our calculated geometry was found to be comparable to previous measurements. The end-diastolic stresses were found to have complex variations, which cannot be determined by adopting an ad hoc stress-free, end-diastolic geometry. The calculated geometry and stress distribution are deemed to be suitable for use as initial states for cardiac cycle simulations.
FINITE ELEMENT BASED ELASTO-PLASTIC ANALYSIS OF CLASSICAL AND FIRST ORDER BEAMS WITH ARMSTRONG–FREDERICK KINEMATIC HARDENING MODEL
Authors: Hashemi Ehsan , Farshi Behrooz
Published: April 2018

This investigation is focused on the elasto-plastic behavior of classical and first order Timoshenko beams by a finite element formulation under two major kinematic hardening models. The approach consists of proposing a finite element formulation with variable stiffness matrix and optimized solution for the Armstrong–Frederick theory together with the Ziegler–Prager model under cyclic flexural and deformation controlled loading conditions. In symmetrical cyclic deformation and flexural controlled states of the first order beams, it was concluded that after several cycles, the total stress-strain curves tend to be coincident. It also corroborates that the anisotropic characteristic cases with symmetric loading exhibit a ratcheting response for both beam models.
GEOMETRIC APPROACH TO SOLVING THE INVERSE DISPLACEMENT PROBLEM OF CALIBRATED DECOUPLED 6R SERIAL ROBOTS
Authors: Nubiola Albert , Bonev Ilian A.
Published: April 2018

This paper presents a simple but efficient way to numerically calculate the inverse displacement problem of calibrated decoupled 6R serial robots. The method is iterative and works with any type of calibrated robot model, such as level-3 models, since it requires no algebraic computation and no resolution of high-order polynomials, only the computation of the forward displacement problem of the calibrated robot model and the inverse kinematics of the nominal robot model. The method proposed can find up to eight possible solutions for a given end-effector pose. A numerical example is presented, with one million arbitrary end-effector poses of a level-3 calibrated ABB IRB 120 robot. The computation time for solving the inverse problem is analyzed, and in most cases is found to be only four times the time needed to calculate the nominal inverse kinematics and the calibrated direct kinematics. Furthermore, the method is fast enough to be implemented directly into the robot controller using the RAPID programming language.
DESIGN AND PERFORMANCE ANALYSIS OF AN AUTOMOBILE-REMOVABLE SOLAR SYSTEM FOR WATER AND CABIN HEATING
Authors: Bentrcia Mohamed
Published: April 2018

A detachable, automotive solar system for water and passenger compartment heating is developed. The study shows that an adjustable 1 m2 solar collector is sufficient to satisfy the needs of a small group during a short camping trip in Saudi Arabia desert. Also it is found that an adequate water temperature in the storage tank, due to ambient solar heating, is maintained in all cold months, except December when it is insufficient. Among the advantages of the system is its entire operation on renewable solar energy and its ability to heat the car compartment whenever the heated water reaches the required temperature and solar energy is still available.
MODIFIED ELECTRICALLY HEATED HOT WATER STORAGE TANK: EXPERIMENTAL INVESTIGATION
Authors: Beithou N.
Published: April 2018

Hot water in residential buildings accounts for 37% of the energy used. In hot water storage tanks (HWST) the average water temperature decreases due to turbulent mixing. A modified design of HWSTs to extend hot water availability is proposed and tested. For this purpose two electrically heated 50 litre commercial tanks were obtained. One was equipped with a semidome to inhibit turbulent mixing. The unmodified was used for comparison. These were tested for three flow rates: 6, 8, and 10 L/min. Higher flow rates of hot water temperatures were obtained from the modified tank. To increase the heating transfer rate fins were added to the electrical heater. Water supply temperature of (60°C) was achieved 12 minutes earlier in the modified tank due to extended heat transfer area.
TRIBOLOGICAL PROPERTIES OF A NEW KIND OF FRICTION-PROMOTING GREASE IN SLIDING POINT CONTACTS
Authors: Ma Wan , Zhu Zhen C. , Peng Yu X. , Chen Guo A.
Published: April 2018

In this paper, the tribological properties and the film-forming properties of the friction-promoting grease (FPG) A under point-contact conditions were investigated by conducting respectively four-ball experiments and FPG A-lubricated ball-and-disc contact experiments. The experimental results indicate that the coefficient of friction (COF) decreases with an increase in the rotating speed at a constant load; FPG A has a good film-forming ability and a good adhesion property; the application of FPG A under hoist’s normal operation conditions could greatly protect the contact surfaces from wear and supply a sufficient COF.
EXPERIMENTAL VERIFICATION OF A PRACTICAL DIGITAL DRIVER WITH SWITCHED GAIN-TUNING FOR FIVE-PHASE STEPPING-MOTORS
Authors: Yagi Keisuke , Hori Noriyuki , Nahon Meyer
Published: April 2018

A digital driver that has a switched self-tuning gain in its current regulator is designed for five-phase stepping motors so that their performance could be improved and adjusted more easily, than with an analog driver. The regulator has a fixed gain block in its feedback loop and an adjustable gain in the feedforward path, replacing the integrator and the high gain that were required in previous designs to achieve good steady-state performance and fast response. Extensive experiments have been conducted under typical and extreme actuation conditions, and revealed that the proposed driver performs better than the analog drivers or their discretized equivalents, especially in eliminating undershoots, which were problematic with previous drivers.
RESEARCH ON FLEXIBLE DRILL STRING VIBRATION INDUCED BY SONIC HARMONIC EXCITATION
Authors: Bu Changgen , Sun Long , Hu Yuanbiao , Xia Bairu
Published: April 2018

The undisturbed sampling of the overburden soil is attracting increased attention due to the rapid increases in the construction of large-scale domestic foundations and environmental protection engineering. To date, systematic theoretical research on sonic drilling technology has rarely been published. In the present paper, the vibration response induced by sonic harmonic excitation is studied by modeling the flexible drill string of a sonic drill; its dynamic theory and design methodology have been developed, which reveal effects of the excitation frequency, the structural parameters on vibration response of the drill string. The study of sonic drill string vibration is beneficial for improving the drilling efficiency and reducing the damage.
HYDRODYNAMIC CALCULATION OF ROTATING WEIS-FOGH-TYPE WATER TURBINE WITH THE ADVANCED VORTEX METHOD
Authors: Ro Ki-Deok
Published: April 2018

In this study, a rotating-type water turbine model applying the principle of the Weis-Fogh mechanism is proposed, and its hydrodynamic characteristics calculated by an advanced vortex method. The unsteady flow and pressure fields around the wing for two revolutions were calculated by changing the uniform flow and maximum opening angle of the wing. The maximum efficiency for one wing of the water turbine was 45.3% at the maximum opening angle of the wing 36° and velocity ratio 2.0. The flow field of the water turbine is very complex because the wing rotates and moves unsteadily in the channel. However, using the advanced vortex method, accurate calculations were possible.