bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing a tapping and drilling measurement system for a performance test using a laser diode, position-sensing detector, and laser interferometer
Authors: Jywe Wenyuh , Chen Chun-Jen
Published: December 2006

Tapping and drilling are frequently used in mechanical working. Previous research on tapping and drilling has mainly focused on cutting force variations, drill and tap wearing, and drill and tap design: machine tool performance has seldom been dealt with. A novel performance test system of tapping and drilling for a computer numerical control (CNC) machine tool is established in the current paper. This system includes a two-dimensional position sensing detector, a laser source, and a laser interferometer. The laser source was fixed on the spindle of the machine tool by the cutter, and the position sensing detector was mounted on the machine tool table. The reflecting mirror of the interferometer was fixed on the z axis of the machine tool, and the laser source of the laser interferometer was mounted on the machine tool table. Therefore, the spindle errors and the z axis position of the machine tool could be recorded by the position-sensing detector and laser interferometer respectively. Consequently the spindle error and z axis motion of the machine tool in the tapping/drilling test could be measured simultaneously. The accuracy of this system in the x-, y-, and z-directions was about 1 μm in each case. The present paper describes the experiments of the position-sensing detector calibration, stability test, tapping test, and drilling test. The findings are discussed below.
The performance and oxidation stability of sustainable metalworking fluid derived from vegetable extracts
Authors: Abdalla H S , Patel S
Published: December 2006

Throughout the world, the production, application, and disposal of metalworking fluid (MWF) must adhere to the requirements of nature and the environment. Plant-derived oils have been researched as the alternative to mineral-based cutting fluids as they are deemed to be more environmentally friendly and sustainable.

This paper investigates different vegetable- and plant-derived oils in their pure state, as blends or as commercially available products within the industry, and measures their relative oxidation stability levels and their ability to perform as a lubricant. A set of standard techniques, such as pressure differential scanning calorimetry (PDSC), which measures the oxidation onset temperature and the oxidation induction time, four-ball tester, sliding resistance value (SRV), and micro tap methods, were utilized to analyse the tribological properties of the fluid.

The results determined that the oxidation stability varies and is dependent on the chemical structure of the oil and its origins, and physiochemical processing during extraction and storage. In relation to oxidation stability being the sole limiting factor, the tribological performance of the oils was affected by their physical and chemical properties. It was apparent from the findings that the physical properties of the oil are also responsible for the low performance of the oil as a metal cutting fluid.
Economic application of piezoelectric actuator in linear vibratory feeding
Authors: Hu Z , Farson D F , Maul G P
Published: December 2006

The research investigated a decoupled vibratory feeding scheme driven by a piezoelectric actuator. In the decoupled design, the action of the horizontal and vertical vibration would be separately controlled to achieve a desired track trajectory and consequently the feed of the part. A computer control method was used to develop voltage input waveforms to control these actuators to produce decoupled movements that cause parts to move forward relative to the track and overcome backsliding and other inefficient feeding motions of conventional operation. To provide a commercial result from research, the authors proposed an economic application of decoupled feeding in an industrial environment, in which a regular PZT bimorph bender is used to drive a linear vibratory feeder in micro-industry. The bimorph actuator is economic and easy to install; however, it needs to be properly controlled to obtain the desired actuation. In the present work, a simple but effective control algorithm was designed to suppress undesired responses of the bimorph actuator, i.e. the disturbance from the harmonic vibration and hysteresis effect. The control algorithm was then downloaded into an ECM for experimental operation. The vibratory feeding effect was then studied to validate the application of decoupled piezoelectric actuation.
Combined discrete event simulation and systems thinking-based framework for management decision support
Authors: Chatha K A , Weston R H
Published: December 2006

A number of modelling approaches, such as enterprise modelling, simulation modelling, and causal loop diagramming, have been used independently for designing systems of different kinds, such as machine systems, social systems, and production systems. Enterprise modelling has its roots in control system design. Simulation modelling has generally been used in re-engineering and optimizing production and service processes, whereas causal loop diagramming (systems thinking) has generally been used for systems designing in management and social sciences. This paper describes the combined use of these three modelling approaches which carry complementary concepts that can be used together for supporting management decisions in designing and changing complex manufacturing enterprises. A decision support framework is presented that is instrumented with combined use of these three modelling approaches and has been tested in production management-related decision making.
Agent-based modelling and control of tele-robotic welding system
Authors: Zhang Lianxin , Gao Hongming , Zhang Guangjun , Wu Lin
Published: December 2006

A new tele-robotic welding system (TRWS) with more intelligent welding sensors was investigated. In order to overcome the control difficulties of the TRWS in traditional teleoperation methods, a new control strategy, ‘macroscopic teleoperation, microscopic autonomous’, was presented. Based on the new control strategy, the tele-robotic welding process is analysed, which requires the coordination among operators and machines, and then utilize the advantages of operators and all machines respectively and fully. Therefore the TRWS was modelled and controlled based on multiagent system technologies. Lastly, some practice welding experiments were carried out and the results demonstrated that the agent-based TRWS could complete the practice welding tasks very well.
Hybrid enhanced genetic algorithm to select optimal machining parameters in turning operation
Authors: Yildiz A R , Ozturk F
Published: December 2006

The current paper presents a hybrid enhanced genetic algorithm that is developed for solving the optimization problems in design and manufacturing. The present approach is applied to optimize turning operation for the determination of cutting parameters considering minimum production cost under a set of machining constraints. A refined design space for population is introduced by integrating the robust parameter design concept into the genetic algorithm to solve multi-objective and single-objective optimization problems. First, the proposed approach is validated using test problems and metrics taken from literature. Finally, it is applied to the turning optimization problem. The computational experimental results show the effectiveness of the proposed approach in the turning optimization problem.
The development of nickel-tungsten carbide functionally graded materials by a laser-based direct metal deposition process for industrial slurry erosion applications
Authors: Yarrapareddy E , Zekovic S , Hamid S , Kovacevic R
Published: December 2006

Functionally graded materials (FGMs) consisting of Ni-tung (nickel-tungsten carbide) powders with different concentrations of tungsten carbide particles are successfully deposited by a laser-based direct metal deposition (LBDMD) process on 4140 steel substrates. The slurry erosion behaviour of the Ni-tung FGMs is studied at different impingement angles. The slurry erosion tests are performed at Southern Methodist University's Center for Laser-Aided Manufacturing using a centrifugal-force-driven erosion-testing machine. For the purpose of comparison, Ni-tung 40 depositions and 4140 steel samples are also tested. The results indicate that the LBDMD process is able to deposit defect-free Ni-tung FGMs with uniform distribution of tungsten carbide particles in a nickel-based matrix. The slurry erosion resistance of Ni-tung FGMs as observed to be much better than that of the Ni-tung 40 and 4140 steels. The superior slurry erosion resistance of Ni-tung FGMs is attributed to the presence of large amounts of very hard tungsten carbide particles. The material removal rate (MRR) values by erosion decrease with a decrease in the impingement angle, except at a 45° impingement angle on 4140 steel. The relationship among the MRRs, the craters' depth of penetration, the areas of the craters formed, the average surface roughness values, and the impingement angles are established for Ni-tung FGMs, Ni-tung 40, and 4140 steels. The surface profiles of the eroded samples are analysed by measuring the depth of penetration of the craters formed by the slurry jet using a needle-shaped probe and a linear scale with a digital readout. The damaged surfaces are characterized by scanning electron microscopy to investigate the possible application of a material failure model, called damage initiation and damage propagation, to the case of the impingement of a mixture of solid and liquid particles on the Ni-tung FGMs, Ni-tung 40, and 4140 steels. The potentiodynamic polarization curves are generated for the three tested materials and to discover the susceptibility of the material in an erosive environment.
A systematic approach for the robust design of scalable product platforms
Authors: Wang M H
Published: December 2006

In today's highly competitive and volatile market, companies are trying to bring their products to the market faster in order to maintain a competitive advantage. One of the strategies is to develop common product platforms for rapid new product development. The objective of this research is to develop a scalable product platform robust design (SPPRD) framework that can assist companies in creating product platforms quickly and efficiently. The essential of this framework is to infuse the robust design concept into the product platform design process. Two objectives of robust design - achieving performance targets and minimizing performance variation are evaluated in the Compromise Decision Support Problem (Compromise-DSP) model. This SPPRD framework is demonstrated with the design of a tube-fin evaporator platform.
Parameter study of the axisymmetric hydromechanical deep drawing process
Authors: Fazli A , Dariani B Mollaei
Published: December 2006

In this paper, hydromechanical deep drawing and the effect of process parameters on the process have been studied using the finite element (FE) method. In order to verify the results of FE simulations, a study has also been carried out using experimental tooling. Numerical results indicate a working zone with a maximum chamber pressure in which the maximum limit drawing ratio (LDR) can be achieved and where the effect of chamber pressure on the process can be shown. Also, the effect of parameters such as initial chamber pressure, die profile radius, blank thickness, and friction effect has been investigated. It is shown that initial chamber pressure has an optimum value in which the maximum LDR can be achieved. Increasing the die profile radius increases the LDR at lower chamber pressures but has no marked effect at higher pressures. The numerical result also shows that increasing the friction between blank and die or blank and blank-holder decreases the LDR value, while increasing the friction between blank and punch increases the LDR value.
Simulating the behaviour of folded cartons during complex packing operations
Authors: Sirkett D M , Hicks B J , Berry C , Mullineux G , Medland A J
Published: December 2006

The folding carton is a widely used packaging solution. Recent European Union packaging legislation has forced carton manufacturers to use lighter-weight grades of carton board. This typically results in a reduction in board stiffness, which can lead to decreased process efficacy or even prevent successful processing. In order to overcome this, end-users lower production rates and fine-tune packaging machine settings for each pack and material. This trial-and-error approach is necessary because the rules relating machine set-up to pack design and material properties are not generally well known. The present study addresses this fundamental issue through the creation of a finite-element computer simulation of carton processing. Mechanical testing was performed to ascertain the key mechanical properties of the carton walls and creases. The carton model was validated against the experimental results and was then subjected to the machine-material interactions that take place during complex packaging operations. The overall approach was validated and the simulation showed good agreement with the physical system. The results of the simulation can be used to determine guidelines relating machine set-up criteria to carton properties. This will improve responsiveness to change and will ultimately allow end-users to process thinner lighter-weight materials more effectively.
A new cyclone separator-based pre-filter design for internal combustion engine applications. Part 2: Parametric study and optimization
Authors: Madhusudhan K , Narasimhan M V , Ravikrishna R V
Published: December 2006

In a previous paper a new design was presented of a cyclone separator based pre-filter along with validation of a numerical model with experimental data. The validated model is used to evaluate certain designs with varying inlet air entry configurations. Furthermore, several cases as part of a detailed parametric study on the new pre-filter design are simulated in terms of geometrical parameters to optimize the performance with respect to overall pressure drop and dust collection efficiency. The results of the parametric study are used to derive a final optimized pre-filter configuration. In addition, based on the results of some of the simulations, a new concept of air filtration which could potentially replace the conventional air filter plus pre-filter configuration is introduced and assessed numerically. This design utilizes the high swirl velocities of air to separate particles as small as 4-5 μm with almost 100 per cent efficiency. More importantly, it offers much lower pressure drop than the total pre-filter plus main filter configuration.
Eddy genesis and transformation of Stokes flow in a double-lid-driven cavity. Part 2: Deep cavities
Authors: Gürcan F , Wilson M C T , Savage M D
Published: December 2006

This paper extends an earlier work [1] on the development of eddies in rectangular cavities driven by two moving lids. The streamfunction describing Stokes flow in such cavities is expressed as a series of Papkovich-Faddle eigenfunctions. The focus here is deep cavities, i.e. those with large height-to-width aspect ratios, where multiple eddies arise. The aspect ratio of the fully developed eddies is found computationally to be 1.38 > 0.05, which is in close agreement with that obtained from Moffatt's [2] analysis of the decay of a disturbance between infinite stationary parallel plates. Extended control space diagrams for both negative and positive lid speed ratios are presented, and show that the pattern of bifurcation curves seen previously in the single-eddy cavity is repeated at higher aspect ratios, but with a shift in the speed ratio. Several special speed ratios are also identified for which the flow in one or more eddies becomes locally symmetric, resulting in locally symmetric bifurcation curves. By superposing two semi-infinite cavities and using the constant velocity damping factor found by Moffatt, a simple model of a finite multiple-eddy cavity is constructed and used to explain both the repetition of bifurcation patterns and the local symmetries. The speed ratios producing partial symmetry in the cavity are shown to be integer powers of Moffatt's velocity damping factor.
Stress concentration factors for the torsion of curved beams of arbitrary cross-section
Authors: Cornwell R E
Published: December 2006

There are numerous situations in machine component design in which curved beams with cross-sections of arbitrary geometry are loaded in the plane of curvature, i.e. in flexure. However, there is little guidance in the technical literature concerning how the shear stresses resulting from out-of-plane loading of these same components are effected by the component's curvature. The current literature on out-of-plane loading of curved members relates almost exclusively to the circular and rectangular cross-sections used in springs. This article extends the range of applicability of stress concentration factors for curved beams with circular and rectangular cross-sections and greatly expands the types of cross-sections for which stress concentration factors are available. Wahl's stress concentration factor for circular cross-sections, usually assumed only valid for spring indices above 3.0, is shown to be applicable for spring indices as low as 1.2. The theory applicable to the torsion of curved beams and its finite-element implementation are outlined. Results developed using the finite-element implementation agree with previously available data for circular and rectangular cross-sections while providing stress concentration factors for a wider variety of cross-section geometries and spring indices.
Performance optimization for two-dimensional rectangular diffuser by momentum injection using computational fluid dynamics
Authors: Singhal T , Singh S N , Mathur S , Singh R K
Published: December 2006

This article explores a non-conventional method for improvement of performance of a wide-angle two-dimensional rectangular diffuser. Computational fluid dynamics investigation has been carried out to analyse the effect of injecting momentum through a moving surface to control the boundary layer separation close to the wall of a two-dimensional rectangular diffuser. A cylinder was placed at the diffuser inlet and rotated at various speeds. It is seen that injection of momentum through the moving surface delays flow separation, thereby increasing the pressure recovery coefficient. An increase in the rotational speed of the cylinder from 1500 to 5500 rad/s improves the pressure recovery coefficient marginally. Placing another cylinder at a preidentified location and rotating both cylinders at the same speed further improves the pressure recovery. Overall improvement in pressure recovery is ∼28 per cent from 0.63 to 0.81. Besides improvement of pressure recovery, the flow distribution in the core region also improves significantly.
The effect of nozzle geometry on the flow characteristics of small water jets
Authors: Ghassemieh E , Versteeg H K , Acar M
Published: December 2006

A wide variety of processes make use of plain orifice nozzles. Fuel injectors for internal combustion engines incorporate these nozzles to generate finely atomized sprays. Processes such as jet cutting, jet cleaning, and hydroentanglement, on the other hand, use similar nozzles, but require coherent jets. The spray or jet characteristics depend on the stability of the flow emerging from the orifice. This problem has been extensively researched for nozzles with diameters above 300 μm. Much less is known about the characteristics of jets produced by nozzles with smaller diameters, where viscous effects and small geometric variations due to manufacturing tolerances are likely to play an increasing role. Results are presented of a wide-ranging investigation of geometry effects on the flow parameters and jet characteristics of nozzles with diameters between 120 and 170 μm. Nozzles with circular cross-section and conical, cone-capillary and capillary axial designs were investigated. For conical and cone-capillary nozzles, the effect of cone angle and effects due to interactions between adjacent nozzles in the multi-hole cone-capillary nozzles were studied. For capillary nozzles, the effects of diameter variations and inlet edge roundness for capillary nozzles were considered. Furthermore, the effect of varying the aspect ratio (ratio of major and minor axes) of elliptical nozzles was studied. Flowrate and jet impact force measurements were carried out to determine the discharge coefficient Cd, velocity coefficient Cv, and contraction coefficient Cc of the nozzles for supply pressures between 3 and 12 MPa. Visualizations of the jet flow were carried out in the vicinity of the nozzle exit in order to identify near-nozzle flow regimes and to study jet coherence. The relationship between nozzle geometry, discharge characteristics, and jet coherence is examined.
Definition of correlations between automotive test environments through mechanical fatigue damage approaches
Authors: Kouta R , Play D
Published: December 2006

The aim of validating the global endurance of a mechanical system is to make sure that it shows no signs of failure during series of specific tests. The latter are carried out in more severe environments than those to which the system is subjected during normal use. The application described here concerns ground vehicles, and the study proposes methods and tools for optimizing and organizing tests. This optimization is based on correlations between different existing test environments. Two main methods of correlation are proposed and developed: correlation based on mechanical loadings and correlation based on mechanical damage. These methods respectively permit analysis of the mechanical loadings that a system undergoes during tests and prediction of the consequences of these loadings. Both analyses help to reduce the duration and number of tests. The analysis of measured loadings appearing in a mechanical system consists in knowing the statistical contents of load signals according to various forms (global statistical distribution, local statistical distribution, distribution of extreme values, dynamic signal behaviour, Markov matrix). Analysis of the consequences of loadings consists in building a spectrum of robustness, a spectrum of mechanical damage by fatigue, and a matrix of mechanical damage. Tools stemming from these analyses permit better evaluation of fatigue life expectancy and better definition of trial environments for endurance testing with an overall severity equivalent to that applied during normal use of the system.
Engine operation for the planetary gear hybrid powertrain
Authors: Ahn Kukhyun , Cho Sungtae , Won Cha Suk , Moo Lee Jang
Published: December 2006

The planetary gear hybrid powertrain (PGHP) is considered as a prospective hybrid electric vehicle (HEV) configuration. However, the optimal control of the system remains controversial because the characteristics of this system are much more complicated than those of conventional systems. This paper presents a case study that reveals the ambiguity of the conventionally-defined optimal operation line. Instead of this engine optimal operation line, the system optimal operation point is suggested. This point is determined by considering the engine efficiency and the transmission efficiency simultaneously. With the system optimal operation point, the fuel economy estimate can be simulated. First, the vehicle cruising at constant velocities was simulated. Then, the vehicle was run at various standard emission test schedules and the mileages were estimated. In each case, the engine operation was analysed to comprehend the optimal operation of the PGHP system. Also, the improvements in fuel economy by optimal operation are presented.
Simulation of the air/fuel mixing of an HSDI diesel engine. Part 1: A new dense spray vapour coupling submodel
Authors: Sterno N , Greeves G , Tullis S , Jiang Xi , Zhao Hua
Published: December 2006

A numerical study has been performed to investigate the soot emission from a high-speed single-cylinder direct injection diesel engine. The computational conditions were set to be the same as the test conditions in the experiments where measurements had been performed at two running speeds with two injector protrusions. It was shown that the KIVA CFD code can predict the experimental trend, where at a low-speed running condition a higher smoke reading is reached when increasing the injector protrusion into the piston chamber and, conversely, a lower smoke reading was recorded for the same change in injector protrusion at a high running speed condition. Although computational predictions yielded the same trend as the experimental results, the magnitudes of the smoke emissions were an order of magnitude over those predicted. Evidence of inappropriate air/fuel mixing of the model was seen via rates of heat release analyses, especially in the high-speed conditions. Therefore, efforts to reduce this discrepancy by way of improvements to the KIVA submodels were made. In particular, modifications to the breakup and evaporation models have been made in order better to represent the mixing of the high-speed liquid jets. A gaseous sphere per liquid droplet model was employed to improve the current KIVA model by improving the mass coupling effects, which effectively delays the addition of spray source terms to the gas phase equations. Results of the modified models showed improvements in the vapour dispersion of the atomizing liquid jet, thus affecting the mixing rates and predicted smoke emissions. Further improvements on the momentum coupling will be presented in Part 2 of this work.
Comparison of the wear exerted on engine valves and seat inserts under various speeds and mileages
Authors: Chun Keyoung Jin , Hong Jae Soo
Published: December 2006

Under actual engine driving conditions, there is a possibility of engine valve and seat insert wear occurring as a result of various speed changes and accumulation of mileage. It is therefore necessary to examine the wear-related problems of engine valves and seat inserts and to determine by comparison whether speed or mileage inflicts the greater wear.

This work focuses on the various degrees of wear produced at three different singular test speeds (10 Hz, 25 Hz, and multi-Hz) and two different cycle numbers (2.1 — 106 and 6.0 — 106). Throughout all tests performed in this study, the temperature of the outer surface of the seat insert was controlled at 350°C and the test load was 1960 N. Wear depths were measured using a confocal laser microscope, and wear mechanisms were observed using a scanning electron microscope.

The extent of wear produced at higher speeds (25 Hz) was found to be greater than that produced at lower speeds (10 Hz) under identical test conditions (temperature, valve displacement, cycle number, and test load). Although test cycle numbers were increased by a factor of 3, for example from 2.1 — 106 to 6.0 — 106, the wear depths were not proportionally increased. Wear occurred rapidly during the initial stages of the test and wear depths increased less significantly with each cycle number. Wear depth of the 2.1 — 106 cycle number test at 25 Hz was much larger than that of the 6.0 — 106 cycle number test at 10 Hz in both the valve and the seat insert. Therefore, this result indicates that speed (Hz) might have a greater effect than mileage (cycle number) on the valve and seat insert while the engine is running. As the cycle number was increased, the wear depth at multi-Hz showed a tendency to near the wear depth at 25 Hz (high speed) rather than that at 10 Hz (low speed).

Adhesive wear and shear strain were observed in the wear mechanisms of the valves. Furthermore, adhesive wear and surface fatigue wear were observed in the wear mechanisms of the seat inserts.
A model for the prediction of the forces at the glenohumeral joint
Authors: Charlton I W , Johnson G R
Published: December 2006

The design, validation, and application of a three-dimensional musculoskeletal model of the upper limb is presented here, for the study of joint, muscle, and ligament forces during selected tasks of daily living. Much of the model was constructed using data gathered from real cadavers, including the extensive ‘visible human’ data set, together with information gathered from published post mortem studies on cadavers. Validation was carried out through comparison of model outcomes with available data in the literature. The model was then used to examine the glenohumeral joint loading during ten previously selected activities of daily living.

The predicted glenohumeral joint contact forces during everyday activities were found to range from 23 to 75 per cent body weight. A linear regression method for estimating the joint load from externally measured kinetics was developed, giving a 95 per cent confidence interval in predicted joint forces of 8 per cent body weight. The model presented here, namely the Newcastle shoulder model, provides a basis for future studies into biomechanical problems relating to the understanding of musculoskeletal pathology and implant design and performance.
Influence of acetabular rim profile on hip dislocation
Authors: Maher S A , Lipman J D
Published: December 2006

Dislocation is the second most common complication in total hip arthroplasty, with reported incidences of up to 8 per cent. The authors' hypothesis is that, by modifying the rim of an acetabular component in order to shift the femoral neck contact position towards the periphery of the acetabulum, the torque required to dislocate the hip joint can be increased without reducing the range of motion. Three liners were designed and their dislocation characteristics mechanically evaluated using a custom experimental test jig designed to simulate the seated leg-cross. On the basis of torque and energy to dislocate and angle at dislocation, the hypothesis was accepted; geometrically varying the contact area between the femoral neck and the acetabular rim appear to be a powerful way to modify hip dislocation characteristics.
Mechanics of the passive knee joint. Part 1: The role of the tibial articular surfaces in guiding the passive motion
Authors: Amiri S , Cooke D , Kim I Y , Wyss U
Published: December 2006

The motion of the unloaded knee is associated with tibial internal rotation and femoral posterior translation. Although it is known that the passive motion is the result of the interaction between the articular surfaces and the ligaments, the mechanism through which the particular pattern of motion is guided is not completely understood. The goal of this study was to focus on the tibial geometry and to identify the roles that its geometric features have in guiding the passive knee motion. The method used in this study simplified the geometry of the tibial plateaux and the menisci into basic features that could be eliminated individually. The generated tibial geometry was implemented in a computer model to simulate the passive motion. Different parts of the geometry were eliminated individually and the comparison between the simulation results was used to identify the role that each part of the geometry had in guiding the passive motion. The medial meniscus was found as the feature that promoted the tibial internal rotation and restrained the femoral posterior translation. The lateral meniscus and the medial aspect of the tibial eminence, on the other hand, were found as the elements that confined the tibial internal rotation.
Custom fabrication of composite tibial hemi-knee joint combining CAD/CAE/CAM techniques
Authors: Jiankang He , Dichen Li , Bingheng Lu , Zhen Wang , Tao Zhang
Published: December 2006

A custom fabrication approach combining computer-aided design (CAD), computer-aided engineering (CAE), and computer-aided manufacturing (CAM) techniques for constructing a novel composite tibial hemi-knee joint is presented. Anatomical modelling was used to provide the computer model with specific geometry for individuals and the finite element method (FEM) was adopted to understand the loading distribution on each component of the composite substitute. Rapid prototyping (RP) was employed to build the negative patterns, based on which the titanium alloy tibial tray and the porous artificial bone were custom fabricated through quick casting and powder sintering techniques. The results show that the titanium alloy component bears most of the loading while the artificial bone shares little, which could prevent it from fracturing in vivo. The final porous artificial bone has controllable microchannels (600 μm) and random micropores (100-200 μm), which ensures full interconnectivity and is expected to address the biological consideration. Clinical application demonstrates that the composite tibial hemi-knee joint has enough mechanical strength and can fit with the upper hemi-knee joint. This novel approach provides a new way to repair large bone defects in the loading sites.
Automated classification of articular cartilage surfaces based on surface texture
Authors: Stachowiak G P , Stachowiak G W , Podsiadlo P
Published: December 2006

In this study the automated classification system previously developed by the authors was used to classify articular cartilage surfaces with different degrees of wear. This automated system classifies surfaces based on their texture. Plug samples of sheep cartilage (pins) were run on stainless steel discs under various conditions using a pin-on-disc tribometer. Testing conditions were specifically designed to produce different severities of cartilage damage due to wear. Environmental scanning electron microscope (SEM) (ESEM) images of cartilage surfaces, that formed a database for pattern recognition analysis, were acquired. The ESEM images of cartilage were divided into five groups (classes), each class representing different wear conditions or wear severity. Each class was first examined and assessed visually. Next, the automated classification system (pattern recognition) was applied to all classes. The results of the automated surface texture classification were compared to those based on visual assessment of surface morphology. It was shown that the texture-based automated classification system was an efficient and accurate method of distinguishing between various cartilage surfaces generated under different wear conditions. It appears that the texture-based classification method has potential to become a useful tool in medical diagnostics.
The use of the Zebris motion analysis system for measuring cervical spine movements in vivo
Authors: Quinlan J F , Mullett H , Stapleton R , FitzPatrick D , McCormack D
Published: December 2006

The cervical spine exhibits the greatest range of motion among the spinal segments due to the complex interaction of its triplanar components of movement. As a result, measurement of movements of the cervical spine and of the various orthoses used in cervical spine injuries has proved difficult with no one method proving satisfactory.

This paper uses the Zebris ultrasonic three-dimensional motion analysis system to measure flexion, extension, range of lateral bending, and range of axial rotation in five similar male and five similar female subjects with no history of neck injuries. The subjects were tested unrestrained and in soft and hard collars, as well as in Philadelphia, Miami J, and Minerva orthoses.

Results show that the Minerva is the most stable construct for restriction of movement in all planes in both groups. Looking at these results allows ranking of the measured orthoses in order of their three-dimensional stability.

Furthermore, by presenting reproducible data incorporating the composite triplanar movements of the cervical spine, thus allowing comparative analysis of the studied orthoses, they propose the Zebris as a reliable, repeatable, and safe method of measurement of cervical spine motion with low intersubject variability.
In vitro validated finite element method model for a human skull and related craniofacial effects during rapid maxillary expansion
Authors: Provatidis C , Georgiopoulos B , Kotinas A , MacDonald J P
Published: December 2006

This paper presents the biomechanical effects on the craniofacial complex during rapid maxillary expansions (RME), by using an in vitro experiment compared with a three-dimensional (3D) finite element model of a human skull. For this purpose, a dry human skull with artificially constructed teeth was used. In addition, a 3D finite element model including the craniofacial sutures was developed based on computed tomography (CT) scans. Initially, two types of models were analysed. In the first model, the total activation of the jackscrew device was applied in one step. In the second model, more steps were applied, taking into account the phenomenon of stress relaxation during RME treatment. Afterwards, a parametric analysis of the finite element method model was performed using three more models in order to evaluate the influence of craniofacial sutures. Both in vitro and finite element results refer to the openings of four critical points (MI, UM, EM, and CN) on the left and right maxilla. Results show that the maxillae open in a pyramidal shape and that the degree of sutures ossification influences the displacement distribution on the craniofacial complex much more than the phenomenon of stress relaxation. The areas of the maximum stresses and displacements were also determined.
Design, validation, and utilization of an articular cartilage impact instrument
Authors: Scott C C , Athanasiou K A
Published: December 2006

This paper describes the development and use of an instrument mechanically to impact bovine articular cartilage and record the event using a piezoelectric accelerometer, as well as to carry out post-impact characterization of the tissue. Two levels of impact (low: 6 cm drop height, 18.4 N tup; high: 10 cm drop height, 27.8 N tup) were chosen such that the former did not show gross damage upon inspection, while the latter showed substantial gross damage. Peak stress, time to peak stress, and impact duration were taken from data recorded by the instrument. Three cartilage biomechanical properties (aggregate modulus, Poisson's ratio, and permeability) were acquired by creep indentation, and tissue morphology rated on a standardized scale was also determined. When subjected to the high level of impact, articular cartilage showed statistically significant ( p < 0.05) differences in all three impact metrics and morphology. This high level of impact also resulted in a 37 per cent decrease in the aggregate modulus of the tissue. Lower drop heights resulted in more consistent impact curves, demonstrated less standard deviation, and did not change the biomechanical properties of the tissues. With the instrument and techniques described in this study, articular cartilage can be subjected to specific levels of impact in order to study injury biomechanics of the tissue at specific levels of mechanical damage.
Performance evaluation of a dental handpiece in simulation of clinical finishing using a novel 2DOF in vitro apparatus
Authors: Yin L , Song X F , Qu S F , Huang T , Mei J P , Yang Z Y , Li J
Published: December 2006

This paper reports on the performance evaluation of a dental handpiece in simulation of clinical finishing using a novel two-degrees-of-freedom (2DOF) in vitro apparatus. The instrumented apparatus consisted of a two-dimensional computer-controlled coordinate worktable carrying a dental handpiece, a piezoelectric force dynamometer, and a high-speed data acquisition and signal conditioning system for simulating the clinical operations and monitoring the dental finishing processes. The performance of the dental handpiece was experimentally evaluated with respect to rotational speed, torque, and specific finishing energy under the applied clinical finishing conditions. The results show that the rotational speeds of the dental handpiece decreased by increasing either the depth of cut or the feed rate at a constant clinically applied air pressure and water flowrate. They also decreased when increasing both the tangential and normal finishing forces. The specific finishing energy decreased with an increase in either depth of cut or feed rate, while the finishing torque increased as either the depth of cut or the feed rate was increased. Implications of these results were to provide guidance for proper applications of dental handpieces in clinical practice.
Structural analysis of steering wheel grip comfort by the semantic differential method
Authors: Nishina K , Nagata M , Ishii N
Published: December 2006

Kansei quality varies with the individual. Therefore, when building a structural model of Kansei quality, it is very important to identify some essential structures by analysing individual differences. In this paper, the semantic differential method is used to improve steering wheel grip comfort. Assuming a hierarchical structural model of the steering wheel grip comfort, the individual differences are analysed using principal component analysis, and then some hierarchical structural models are built using graphical modelling. As a result, two remarkably different structures are built. Some guidelines for developing steering wheel production can be shown by comparing the different structures.
Autonomous pet-type robot with emotion behaviour-learning system based on neuromodulators
Authors: Akiguchi S , Maeda Y
Published: December 2006

In recent years, research on embedding human emotions in autonomous mobile robots has been carried out. Research based not only on psychological but also on physiological knowledge of emotions has also been performed, and research in neuroscience is gradually making clear the role of neuromodulators. Meanwhile, other researchers have examined the influence between neuromodulators and meta-parameters of the reinforcement system for learning. In this research, attempts are made to develop an emotion generation system for a pet-type robot based on the relationship between the human learning system's meta-parameters, emotions, and neuromodulators, such as adrenaline, noradrenaline, serotonin, and dopamine.

The proposed architecture for the emotion generation system uses a Q-learning method with meta-parameters controlled by neuromodulators. Experimental results confirming the efficiency of the method are reported.
Effect of spatial colour sequence with minimum distance on human colour impression and its model
Authors: Sugano N , Negishi Y , Ishihara T
Published: December 2006

The present study investigates the effect of the fundamental six-colour (cyclic) sequence on human colour impression. The different effects of two spatial sequences are investigated under the consideration of a hexagonal diagram that is a projection of RGB colour space from white to black. The hexagonal diagram corresponds roughly to the hue circle indicated by both hue and saturation in an HLS system. The projected route area indicates the magnitude of naturalness (as in rainbows) for colour sequences. The minimum sequence is similar to the order of colours in rainbows, whereas the non-minimum sequence is completely different. Therefore, a human colour impression model is proposed using the projected route area indicated by both hue and saturation. It is clarified that the majority of subjects of nearly all ages has a natural impression when the minimum route area is large. In addition, the human colour impression is compared with the human colour impression model. This model is intended to be employed in order to design commodities, goods, buildings, and towns to have the most effective colour sequence.
Conceptual modelling and software platform for Kansei retrieval systems
Authors: Ogino A , Kato T
Published: December 2006

This study addresses the design and development of the Kansei retrieval system. It is a personalized system that retrieves multimedia contents, such as image or video, suitable for individual subjective criteria from a database or web. The Kansei retrieval system has received much attention recently. However, development of the system is ad hoc, because systematic design methodology of the system is scarce. This paper proposes the Kansei framework diagram as a conceptual modelling for designing the system as well as the software platform for developing the system. The proposed conceptual modelling makes the design process of the system clear, and the proposed software platform reduces programming steps and the development period for the system.
Kansei engineering and application of the rough sets model
Authors: Nagamachi M , Okazaki Y , Ishikawa M
Published: December 2006

Kansei engineering was founded by M. Nagamachi at Hiroshima University about 30 years ago and has spread throughout the world. The aim of Kansei engineering is to develop a new product by translating a customer's psychological needs and feeling (Kansei) concerning it into design specifications. Kansei data have so far been analysed using a multivariate statistical analysis to create new products, but Kansei data do not always have linear features assumed under normal distribution. The rough sets theory is able to deal with any kind of data, irrespective of linear or non-linear characteristics of the data. The results based on statistical analysis and rough sets theory are compared.
Synesthesia and common recognition concerning music and colour
Authors: Yamawaki K , Shiizuka H
Published: December 2006

This paper discusses the common recognition of music and colour from the viewpoint of synesthesia. The focus is especially placed on coloured hearing synesthesia. Coloured hearing synesthestesia experiences a crossing of senses where a brain recognizes music aurally as colour. An experiment, in the format of questionnaires, was conducted where subjects were required to listen to music and select a representative colour for the music. The analysis of the questionnaires obtained the following results: it suggested that synesthesia exists at a subconscious level in human beings and that synesthesia is caused by influences of common recognition of music and colour associations.
Overview of the Kansei system
Authors: Shiizuka H , Watada J
Published: December 2006

The current paper presents an overview of the Kansei system. The primary purpose of this paper is to construct a framework of the Kansei system. It is shown that the Kansei system consists of four quadrants that correspond to Kansei expression theory, Kansei recognition theory, and cognitive science and modelling. Also a survey of the paper in each area is given to realize the framework. Therefore the objective of this paper is to discuss the basic concepts and methods of the system and to provide a framework for future Kansei-oriented research.