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Designs for improved railroad track structure are needed to ensure safety, reliability and profitability as the railroads strive to compete with other means of transport. The large number of precast sleepers produced in the country calls for an optimal design inthe interest of economy. Use of optimisation methods can provide a scientific approach toarrive at a leastcost design. In this paper, optimal design of broad gauge prestressed concrete sleepers for tangent tracks is presented considering the current design standards by Research Designs and Standards Organisation (RDSO). Formulations for optimal design for the conventional 22.9 t and proposed 25 t axle loads are presented along with identification of design variables, objective function and constraints. Optimisation was carriedout in two phases: first, by keeping the geometry constant (for a constant mould size, as presently used) and secondly, also by varying the sleeper cross-section geometry. Among the non-traditional optimisation techniques, genetic algorithm for a constrained optimisation problem using adaptive penalty parameter and adaptive genetic algorithm was used. A MATLAB program has been developed based on the formulations. The optimal solutions are summarised here.

[EN] Salt is one of the most widely used additives in food industries because of its low cost and varied properties. It has a preservative and antimicrobial effect as a direct consequence of the capacity of sodium chloride to reduce water activity values. In addition, sodium chloride is a flavour enhancer as a consequence of its effect on different biochemical mechanisms. It also has flavour enhancing effects from reducing or enhancing the enzymatic activity of some enzymes responsible for the development of different organoleptic parameters. Trends in sodium chloride use in food industries point to salt replacement or reduction by means of the use of sodium chloride substitutes such as KCl or phosphates; flavour enhancers and the optimisation of the physical form of salt. This trend has arisen as a result of the greater awareness of the negative effects of excess dietary intake of sodium, which has been linked to hypertension and consequently an increased risk of cardiovascular disease. The average total daily sodium intake per individual in developed countries is 4-5g of Na, which is up to 25 times greater than the minimum adult requirement. © 2011 The Authors. International Journal of Food Science and Technology © 2011 Institute of Food Science and Technology.

We report on the optimisation of a recently developed high performance 0-3 piezoelectric composite comprising of the piezoelectric Lead Zirconate Titanate (PZT) powder and a liquid crystalline thermosetting matrix polymer (LCT). The matrix polymer is a liquid crystalline polymer comprising of an HBA-HNA backbone with phenylethynyl end-groups. The use of a high performance polymer makes the composite a possible candidate to be used in sensor applications at elevated temperatures. The composite properties were optimised by calcining the PZT powder at different temperatures, prior to mixing the powders into the LCT matrix. The aim is to study the effect of the calcining temperature on the piezoelectric properties of the composite The PZT powders were characterised by X-ray diffraction and scanning electron microscopy. The dielectric constant and piezoelectric charge constant (d 33 ) of the composite samples was measured. It was found that a relationship exists between the calcining temperature of the PZT powder and the piezoelectric properties of the composites. A maximum voltage constant of g 33 ?=?63 mVm/N was obtained for a composite containing 40% (by volume) of PZT powder calcined at 1150°C. © 2010 The Author(s).

In mobile cellular networks the handover (HO) algorithm is responsible for determining when calls of users that are moving from one cell to another are handed over from the former to the latter. The admission control (AC) algorithm, which is the algorithm that decides whether new (fresh or HO) calls that enter a cell are allowed to the cell or not, often tries to facilitate HO by prioritising HO calls in favour of fresh calls. In this way, a good quality of service (QoS) for calls that are already admitted to the network is pursued. In this paper, the effect of self-optimisation of AC parameters on the HO performance in a long term evolution (LTE) network is studied, both with and without the self-optimisation of HO parameters. Simulation results show that the AC parameter optimisation algorithm considerably improves the HO performance by reducing the amount of calls that are dropped prior to or during HO. © 2011 IEEE.

In mobile cellular networks the handover (HO) algorithm is responsible for determining when calls of users that are moving from one cell to another are handed over from the former to the latter. The admission control (AC) algorithm, which is the algorithm that decides whether new (fresh or HO) calls that enter a cell are allowed to the cell or not, often tries to facilitate HO by prioritising HO calls in favour of fresh calls. In this way, a good quality of service (QoS) for calls that are already admitted to the network is pursued. In this paper, the effect of self-optimisation of AC parameters on the HO performance in a long term evolution (LTE) network is studied, both with and without the self-optimisation of HO parameters. Simulation results show that the AC parameter optimisation algorithm considerably improves the HO performance by reducing the amount of calls that are dropped prior to or during HO. © 2011 IEEE.

Previous studies have shown that building, social and personal factors can influence one's perceived health and comfort. The aim of the underlying study was to get a better understanding of the relationships between these factors and perceived comfort. Self-administered questionnaires from 5732 respondents in 59 office buildings and building-specific data from the European Health Optimisation Protocol for Energy-efficient buildings (HOPE) study were used. Principal Component Analysis (PCA), reliability analyses, and linear regression analysis were performed. The outcome showed that perceived comfort is strongly influenced by several personal, social and building factors and that their relationships are complex. Results showed that perceived comfort is much more than the average of perceived indoor air quality, noise, lighting and thermal comfort responses. Perceived comfort is a phenomenon that deserves more research. © 2010 Elsevier Ltd.

Software development organisations are under heavy pressure to complete projects on time, within budget and with the appropriate level of quality, and many questions are asked when a project fails to meet any or all of these requirements. Over the years, much research effort has been spent to find ways to mitigate these failures, the reasons of which come from both within and outside the organisation's control. One possible risk of failure lies in human resource management and, since humans are the main asset of software organisations, getting the right team to do the job is critical. This paper proposes a procedure for software project managers to support their project scheduling and team staffing activities - two areas where human resources directly impact software development projects and management decisions - by adopting a genetic algorithm approach as an optimisation technique to help solve software project scheduling and team staffing problems.

We report on the optimisation of a recently developed high performance 0-3 piezoelectric composite comprising of the piezoelectric Lead Zirconate Titanate (PZT) powder and a liquid crystalline thermosetting matrix polymer (LCT). The matrix polymer is a liquid crystalline polymer comprising of an HBA-HNA backbone with phenylethynyl end-groups. The use of a high performance polymer makes the composite a possible candidate to be used in sensor applications at elevated temperatures. The composite properties were optimised by calcining the PZT powder at different temperatures, prior to mixing the powders into the LCT matrix. The aim is to study the effect of the calcining temperature on the piezoelectric properties of the composite The PZT powders were characterised by X-ray diffraction and scanning electron microscopy. The dielectric constant and piezoelectric charge constant (d 33 ) of the composite samples was measured. It was found that a relationship exists between the calcining temperature of the PZT powder and the piezoelectric properties of the composites. A maximum voltage constant of g 33 ?=?63 mVm/N was obtained for a composite containing 40% (by volume) of PZT powder calcined at 1150°C. © 2010 The Author(s).

A new superalloy, ATI 718Plus alloy (718Plus), has been developed to have a 55°C higher temperature capability over the traditionally used alloy 718, while maintaining favourable processing characteristics and intrinsic raw material costs. The fatigue and dwell fatigue behaviour of four microstructural variations of 718Plus are evaluated and compared with Waspaloy: standard heat treated condition (HT1), standard heat treated condition with thermal exposure at 732°C (1350°F) for 1000 h (HT2), fine grain condition with a modified d phase (HT3) and fine grain overaged through modified heat treatment (HT4). Fatigue crack growth rate tests were performed at 649°C (1200°F) and 704°C (1300°F) under constant amplitude loading at 10 Hz or with a 100 s tension dwell. The results show that the steady state fatigue crack growth rates of each microstructural variation and both alloys are identical, with all of the 718Plus variations showing a clear advantage over Waspaloy in the fatigue crack threshold regime. The 718Plus variants HT1 and HT3 exhibited the highest fatigue crack growth threshold, followed closely by HT4 and finally HT2. At 649°C (1200°F), the 718Plus alloys had average threshold values ranging from 8·8 to 10·4 MPa m1/2 whereas the Waspaloy material was 6·1-7·5 MPa m1/2. At 704°C (1300°F), the advantage increased with the 718Plus alloys having average threshold values ranging from 10·1 to 11·6 MPa m1/2 compared with Waspaloy, which exhibited average threshold values of 6·6-7·7 MPa m1/2. Dwell fatigue results show that Waspaloy has better resistance to crack propagation under dwell conditions; however, optimisation of the precipitate phase (HT2) shows vast improvement in the dwell fatigue resistance of 718Plus. © 2011 Canadian Institute of Mining, Metallurgy and Petroleum.

This paper presents a framework for re-designing a failed automotive component subjected to cyclic loading. In the automotive industry, some parts fail before completing their design life. These failed components have to be re-designed using modern optimisation tools. In this paper, a failed clutch fork was completely re-designed using topology and the shape optimisation approach. Stress-life fatigue analysis was conducted to correlate the crack location between the failed component and the simulation model. A new design proposal was determined with the topology optimisation approach, and then design optimisation by response surface methodology was effectively used to improve the new clutch fork design. The mass reduction obtained was 24%. A maximum stress reduction of 9% was achieved, and the rigidity was improved up to 37% in comparison to the original clutch fork.

Bu çalışma, 01-04 Haziran 2008 tarihleri arasında Bursa[Türkiye]'da Uludağ Üniversitesi'nde düzenlenen 4. Automotive Technology Conference on Vehicle Design, Development and Manufacturing (OTEKON 08 - VDDM)’da bildiri olarak sunulmuştur. Thin-walled structural members contribute significantly to the ability of an automobile body to absorb energy during frontal impact. The objective of this paper is to improve the energy absorption performance of crash tubes that are placed behind the bumper in automotive vehicles using shape and size optimisation. The best cross section is determined initially, and then dynamic axial crushing simulation is carried out on thin-walled octagonal tube, which has crush initiators. In order to maximise the absorbed energy, shape and size, optimisation techniques are applied using a response surface approximation technique. The design of experiment method is employed to construct the response surfaces. An explicit finite element code, LS-DYNA, was used to implement the parallel computations.

The simultaneous heat exchanger network (HEN) synthesis problem is generally formulated as a mixed integer non-linear programming (MINLP) problem by using superstructures, which embed several possible stream matches and various alternative HEN designs. The superstructures proposed by Yee et al. [1] and by Floudas et al. [2] are used for this purpose. In the present work, the graph theoretic principles used by Shivakumar and Narasimhan [3] to develop an efficient nonlinear program (NLP) formulation for Yee superstructure has been extended to the Floudas superstructure. A comparison of the NLP formulations based on the two superstructures, in terms of efficiency, scalability, convergence and quality of solution has been carried out using several test problems available in the literature. It has been shown that the Floudas superstructure is superior in terms of these performance metrics, and appears to be the best suited for optimisation based HEN synthesis. � 2010 Indian Institute of Chemical Engineers.

Viscosity modifying admixtures (VMAs) are high molecular weight, water soluble organic polymers that are used to stabilise the rheological properties and consistency of self-compacting concrete (SCC). Most studies on VMA focus on the influence of different types and dosages of VMA on the rheological properties and the compatibility issues between superplasticiser and VMA. To obtain the desired rheological properties and to reduce the cost, optimisation of the VMA dosage is essential. In the present study, a simple method was developed for optimising the VMA dosage for the cementitious pastes of different water to powder ratio. The principle of this method was based on Stokes' law. Rheological properties of SCC pastes with VMA were studied using a viscometer. The studies were also extended to concrete for validation of the optimised dosage obtained from the cementitious paste tests. The results obtained clearly indicate that the optimised dosage obtained by using the empirical method yields SCC without segregation. The lower dosages are not sufficient enough to control the segregation. On the other hand, dosages higher than optimal resulted in reduced slump flow. � 2009 RILEM.

cited By 50; International audience; Ca3Co4O9 (349) thermoelectric (TE) oxide ceramics were successfully prepared by Spark Plasma Sintering process. The effects of the uniaxial pressure (30-100 MPa), the dwell temperature (700-900 °C) and the cooling rate were investigated. Microstructure analyses have revealed strong enhancements of the bulk density as the pressure level and the applied temperature during the SPS process are increased. Mechanical properties were investigated by using instrumented nanoindentation and three point bending tests. Hardness, elastic modulus, strength and fracture toughness were shown to improve drastically and depend on the processing parameters. Thermal expansion measurements reveal a noticeable anisotropy induced by unidirectional hot pressing. The mechanical, thermal and thermoelectric properties were correlated to the microstructure and crystallographic texture of the resulting ceramics. © 2010 Elsevier Ltd. All rights reserved.

The Department of radiology of the Hospital Trousseau (Paris) and IRSN have initiated in 2007 a detailed analysis of doses delivered to children undergoing CT examinations. This study involved three types of CT examination (chest, abdomen + pelvis and petrosal bones) and three age groups (new born to 1 year, 4 to 6 years and 9 to 11 years). A first analysis of doses was realised on a six months period of activity at the end of 2006. It stated that the standardized protocols of the scanner, that satisfied the relevant dosimetric requirements, were regularly modified by the operator to acquire the CT slides: the practice among the department was heterogeneous and the mean values of DLP were systematically higher than those recommended. The whole staff of the department has been informed of these first results and made aware of optimization of delivered doses. The standardized protocols of the scanner have been optimized. A second analysis, similar to the first one, was conducted in 2008. It showed the harmonization of the practice among the department, a significant decrease in the mean DLP (-50% for chest CT) and the respect for the dosimetric requirements for the three examinations concerned. © EDP Sciences, 2010.; En 2007, le service de radiologie de l’Hôpital Trousseau (Paris) et l’IRSN ont initié une analyse détaillée des doses délivrées lors d’examens scanographiques chez l’enfant. Cette étude a porté sur trois types d’examen (thorax, abdomen-pelvis et rochers) et trois tranches d’âge (nouveau né à 1 an, 4 à 6 ans et 9 à 11 ans). Une première analyse des doses a été réalisée a posteriori sur l’activité du second semestre 2006. Elle a montré que les protocoles d’acquisition du scanner, qui satisfaisaient aux recommandations dosimétriques en vigueur, étaient mal respectés dans le service : les pratiques étaient hétérogènes et les valeurs moyennes de PDL supérieures aux recommandations. Après ces premiers résultats, une action de sensibilisation à l’optimisation des doses a été menée auprès du personnel et les protocoles d’acquisition du scanner ont été optimisés. L’analyse dosimétrique reprise en 2008 suivant le schéma de 2006 a montré une harmonisation des pratiques au sein du service, une diminution significative des PDL moyens (-50 % par exemple en scanographie thoracique) et le respect systématique des recommandations dosimétriques pour les trois examens étudiés.

One strategy to minimise petroleum fuel consumption of a Plug-in Hybrid Electric Vehicle (PHEV) is to attain the lowest admissible battery State of Charge (SOC) at the end of driving cycle while following an optimal SOC profile. The challenge of an optimisation algorithm is to find this optimal profile by using least future information about the power demand. An application of Equivalent Consumption Minimisation Strategy (ECMS) for PHEV is presented in this paper and benchmarked against the dynamic programming (DP) for information requirement and optimality. The optimality is assessed in simulation by considering petroleum fuel economy and deviation of the optimal SOC profile from a reference profile for different driving scenarios and battery sizes. Results show that for longer distances and larger battery sizes, ECMS and DP provide similar fuel economy and SOC profiles. A sensitivity analysis with respect to driving distance is presented at the end of the paper.

The Variable-Flow Ducted Rocket (VFDR) is a type of ramjet that can control the fuel mass flow to the combustion chamber. It combines the high efficiency at high-speed of ramjets with the throttlability of turbofans, and this makes VFDR propulsion an excellent choice for high speed, long range missiles. This is especially true because the throttlability enables full flight optimisation, which has the potential to significantly increase the performance (range, terminal velocity, intercept time) with regard to standard ramjets. Previous work demonstrated mid-course guidance of a VFDR powered missile based on offline static flight range optimisation. Using this approach, flight transitions, that can have a large effect on performance, are never quite optimal, and optimisation goals other than range are non-trivial. Offline dynamic flight optimisations, which do incorporate transitions and allow other optimisation criteria, are not practical for use in guidance, because of the large amount of possible scenario's, especially when many target updates are sent. In this paper, the feasibility of online dynamic optimisation of the mid-course flight of a Meteor-like missile is demonstrated, that does not have the limitations of off-line optimisations. A Collocation method is applied to a two-phase non-linear programming problem, in order to optimise 2 controls of a 5 state missile model at intervals of several seconds. Several scenarios are presented, in which the effects are shown of different optimisation criteria, as well as the effects of changes in the target state. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

This paper introduces a new hybrid optimisation approach by combining immune algorithm and simulated annealing algorithm. The main goal of the present research is to develop a novel optimisation approach for the solution of engineering optimisation problems. To demonstrate the effectiveness and robustness of the proposed approach, it is applied to engineering optimisation problems including the multi-pass turning problem taken from the literature and a shape design optimisation problem from automotive industry. Compared with other existing approaches in the literature, the proposed approach is very useful for optimal design and manufacturing.

Nowadays, the general trend towards to minimally invasive interventions is present in all the medical domains. For the surgical intervertebral spinal disc cutting or removal domain, it is particularly a necessity because the manual methods currently employed are tedious, time consuming and taxing on the hands of the practitioner. In that context, new devices that are small enough to pass through a small opening in the skin or through a small portal are required. A detailed analysis of current cutting methods that are or could be used for disc and disc nucleus removal provided that ultrasonics technology should be investigated as a possible solution. The study of ultrasonics technology to fulfil the overall cutting function needed for spinal annulus and nucleus disc material removal is based on a design methodology that breaks down the overall cutting function in many partial functions. The applied design methodology consists in drawing a complete catalogue of solutions for each partial function. Based on a predetermined choice of criteria for each partial function, the evaluation and the classification of each solution allows determination of the best solutions for each partial function. A new ultrasonic transducer designed device composed of a piezoelectric stack for the source of energy and movement, a transmission partial function with rods or discs, an amplification partial function with exponential horns and the cutting partial function solutions is detailed. Existing analytical methods for the design of ultrasonic transducers are mostly based on quarter wavelength segments used to build the transducer. The modeling of that transducers with a finite element method (FEM) avoids building the prototypes and constitutes progress. Analytical models different from the quarter wavelength approach have already been developed and are very useful when used in an optimization process. Furthermore, when the geometry of the analyzed model is not straightforward, a FEM optimization approach to solve that kind of problems can be a valid solution too. Some existing optimization algorithms and other already developed pseudo-gradient methods applied to optimize the analytical models of the ultrasonic transducers are not valid for numerical optimizations where the computing time is a key factor. This leads to the development a new genetic algorithm (GA) optimization methods. One advantage being that the number of parameters to be optimized does not change the complexity of the algorithm unlike other algorithms. Three GAs with improvements done on different parts are discussed, implemented and tested. One GA is chosen to optimize the transducer model with numerical methods. As the main drawback with FE optimizations is the amount of computation time spent for each simulation, this creates a need to develop numerical 2D models that can be quickly simulated but with accurate results. Ultrasonic transducer prototypes are also built and measured. As the prototype has to be used for the cutting or the removal of spinal disc material, the cutting effect of the prototypes has been tested and evaluated.

The Variable-Flow Ducted Rocket (VFDR) is a type of ramjet that can control the fuel mass flow to the combustion chamber. It combines the high efficiency at high-speed of ramjets with the throttlability of turbofans, and this makes VFDR propulsion an excellent choice for high speed, long range missiles. This is especially true because the throttlability enables full flight optimisation, which has the potential to significantly increase the performance (range, terminal velocity, intercept time) with regard to standard ramjets. Previous work demonstrated mid-course guidance of a VFDR powered missile based on offline static flight range optimisation. Using this approach, flight transitions, that can have a large effect on performance, are never quite optimal, and optimisation goals other than range are non-trivial. Offline dynamic flight optimisations, which do incorporate transitions and allow other optimisation criteria, are not practical for use in guidance, because of the large amount of possible scenario's, especially when many target updates are sent. In this paper, the feasibility of online dynamic optimisation of the mid-course flight of a Meteor-like missile is demonstrated, that does not have the limitations of off-line optimisations. A Collocation method is applied to a two-phase non-linear programming problem, in order to optimise 2 controls of a 5 state missile model at intervals of several seconds. Several scenarios are presented, in which the effects are shown of different optimisation criteria, as well as the effects of changes in the target state. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Precast concrete pipe racks are an economically advantageous alternative to steel pipe racks in industrial projects like refineries and petrochemical plants. One major reason for this is the elimination of fire proofing needs for the precast element. Optimal design of the concrete elements would further lower the cost. This paper deals with the optimal design of precast concrete pipe racks, considering design variables such as member sizes, grades of concrete and steel, and reinforcement area. Genetic algorithms (GA) have been used for optimisation and a program in VC++ has been developed to arrive at the optimal solution, which corresponds to overall cost, satisfying design criteria for strength and limiting deflection. Proposals for most favourable jointing mechanisms in terms of cost and constructability have also been given.

The fresh concrete properties of self-compacting concrete (SCC) greatly depend on the paste composition and paste content. As far as high performance concrete is concerned, apart from cement and water, mineral and chemical admixtures play a vital role especially in the paste formulation of SCC. Most of the studies focus only on the influence of the different dosages of mineral and chemical admixtures on the performance of SCC. Moreover, the production cost of SCC is high due to the usage of these admixtures, especially the chemical admixtures for enhanced performance. Hence there is a need for optimised use of the mineral and chemical admixtures. In the present investigation, a new systematic approach based on the concepts of particle packing and rheology was adopted for optimising the powder combinations (cement and fly ash) and superplasticiser (Polycarboxylate based ether) dosage respectively. An empirical test was conducted to optimise the cement - fly ash combination, while the superplasticiser dosage was optimised for 5 different w/p ratios using mini slump tests on cement paste. An attempt was made to understand the influence of optimised dosage of superplasticiser for different w/p ratio on the rheological properties of the cementitious paste. The optimised dosage of mineral and chemical admixtures of the paste was validated in concrete. The results indicate that the slump flow of concrete for the optimised dosage of superplasticiser for different w/p ratio ranges from 550 mm to 650 mm with T500 time ranging from 1 to 6 seconds.

During the recent years it has become more and more clear that one of the major burdens to soldiers are batteries. Each electronic device has its own battery. And none of these are interchangeable. And they all have a different runtime. So in everyday practice he is continuously on the wake for systems failing due to empty batteries. And, to be expected, the one piece of equipment he really needs his final battery does not fit into. Two projects have been carried out in cooperation with the Dutch MoD to reduce these problems and are described in this paper. For the D2S2 the "Dual Source Energy Grid" concept has been developed. The "switch" electronics have been realised on breadboards and semi-field proof casings and are currently under examination by different units. The theory and functionality's of these have been presented earlier. Within the Dutch 11 Air Manouvre Brigade the "battery problem" of a scout platoon have been analysed. For this specific case an ad-hoc approach has been chosen to come to an operational improvement as soon as possible. Results of these two projects will be presented.

During the recent years it has become more and more clear that one of the major burdens to soldiers are batteries. Each electronic device has its own battery. And none of these are interchangeable. And they all have a different runtime. So in everyday practice he is continuously on the wake for systems failing due to empty batteries. And, to be expected, the one piece of equipment he really needs his final battery does not fit into. Two projects have been carried out in cooperation with the Dutch MoD to reduce these problems and are described in this paper. For the D2S2 the "Dual Source Energy Grid" concept has been developed. The "switch" electronics have been realised on breadboards and semi-field proof casings and are currently under examination by different units. The theory and functionality's of these have been presented earlier. Within the Dutch 11 Air Manouvre Brigade the "battery problem" of a scout platoon have been analysed. For this specific case an ad-hoc approach has been chosen to come to an operational improvement as soon as possible. Results of these two projects will be presented.

The paper presents results of a FEA-based tool design optimisation for a clinching process with an open multiple-part die. The studied materials are the bake-hardening steel CR240BH (1.5 mm) on the punch side and the die-cast aluminium alloy AlSi10MnMg (2.95 mm) on the die side. The objective of the optimisation was to minimise probability of cracks that appear at the outer circumference of the bottom of the clinch joint in AlSi10MnMg. In the framework of the optimisation, it was possible to minimise crack probability by varying geometrical parameters of the tools though at the cost of slightly worse but still tolerable geometrical parameters of the clinch joint. German Federation of Industrial Research Associations (AiF), Cologne German Federal Ministry of Economic Affairs and Energy (BMWi) Volkswagen AG BTM Blechverbindungstechnik GmbH

The emergence of huge container ships together with the scarcity of yard land put an enormous pressure on authorities to adopt advanced technologies to increase the throughput of current container terminals. Automated Container Terminals (ACT), using advanced material handling technologies, are recently considered as candidates for increasing the performance of manually operated yards. In this paper, an ACT that employs Linear Motor Technology is designed. A multi attribute decision making method is employed to find the optimum number of conveyor shuttles in the terminal. Simulations demonstrate a double increase in the throughput of ACT compared to the similar one with manual operations. © 2001 EUCA. 289 294 Sponsors: Directorate General XII of the European Commission Faculdade de Engenharia da Universidade do Porto Conference code: 112066

Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models based on crash dummies. These models inherit the apparant differences between dummies and the real human body. Furthermore, crash dummies are only available for a limited set of body sizes. In order to assess passive safety for different body sizes, a method has been developed to generate models representing subjects of varying anthropometry. This method has been applied to 'scale' crash dummy models towards different body sizes and proportions. As a next step, models of the real human body for impact loading have been developed. A combination of modelling techniques is applied using rigid bodies for most body segments, but describing the thorax as a flexible structure. The models allow simulation of global injury criteria like chest-deflection, acceleration and neck loads. For a more detailed analysis, submodels can easily be integrated into the current whole body models. Human body models of different sizes are being developed to allow crash safety desgn based on human body models with realistic anthropometry distributions

Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models based on crash dummies. These models inherit the apparant differences between dummies and the real human body. Furthermore, crash dummies are only available for a limited set of body sizes. In order to assess passive safety for different body sizes, a method has been developed to generate models representing subjects of varying anthropometry. This method has been applied to 'scale' crash dummy models towards different body sizes and proportions. As a next step, models of the real human body for impact loading have been developed. A combination of modelling techniques is applied using rigid bodies for most body segments, but describing the thorax as a flexible structure. The models allow simulation of global injury criteria like chest-deflection, acceleration and neck loads. For a more detailed analysis, submodels can easily be integrated into the current whole body models. Human body models of different sizes are being developed to allow crash safety desgn based on human body models with realistic anthropometry distributions

Date of Conference: 10–12 July, 1997 Conference name: 7th International Workshop on Logic Programming Synthesis and Transformation Workshop, LOPSTR’97 Schema-based logic program transformation has proven to be an eective technique for the optimisation of programs. This paper results from the research that began by investigating the suggestions in [11] to construct a more general database of transformation schemas for optimising logic programs at the declarative level. The proposed transformation schemas fully automate accumulator introduction (also known as descending computational generalisation), tupling generalisation (a special case of structural generalisation), and duality laws (which are extensions to relational programming of the rst duality law of the fold operators in functional programming). The schemas are proven correct. A prototype schema-based transformation system is evaluated. © Springer-Verlag Berlin Heidelberg 1998.

The processing of seismic data, for the imaging of the earth's subsurface, is pushing current computational possibilities to the limit. In this paper results are presented obtained by optimisation and parallelisation of two innovative seismic algorithms with the use of PVM and FORGE. It shows that where the algorithm is CPU bound, a very significant speedup can be acquired, whereas IO-bound algorithms cannot take advantage of the parallel implementation. This leads to two distinct approaches for optimisation. © Springer-Verlag Berlin Heidelberg 1996.

In view of the high investment and tooling cost of a CNC machining centre, the cutting and idle times should be optimised by considering the tool consumption and the non-machining time cost components. In this paper, we propose a detailed mathematical model for the operation of a CNC machine tool which includes the system characterisation, the cutting conditions and tool life relationship, and related constraints. This new module will be a part of an overall computer-aided process planning system to improve the system effectiveness and to provide consistent process plans. A hierarchical approach is presented for finding tool-operation assignments, machining conditions, appropriate tool magazine organisation and an operations sequence which results in the minimum production cost. © 1996 Springer-Verlag London Limited.

The processing of seismic data, for the imaging of the earth's subsurface, is pushing current computational possibilities to the limit. In this paper results are presented obtained by optimisation and parallelisation of two innovative seismic algorithms with the use of PVM and FORGE. It shows that where the algorithm is CPU bound, a very significant speedup can be acquired, whereas IO-bound algorithms cannot take advantage of the parallel implementation. This leads to two distinct approaches for optimisation. © Springer-Verlag Berlin Heidelberg 1996.