bluuebunny/crossref_metadata_2025 huggingface dataset:
High plasma levels of soluble P-selectin are predictive of venous thromboembolism in cancer patients: results from the Vienna Cancer and Thrombosis Study (CATS)
Authors: Ay Cihan , Simanek Ralph , Vormittag Rainer , Dunkler Daniela , Alguel Guelay , Koder Silvia , Kornek Gabriela , Marosi Christine , Wagner Oswald , Zielinski Christoph , Pabinger Ingrid
Published: June 2008

Cancer patients are at high risk for venous thromboembolism (VTE). Laboratory parameters with a predictive value for VTE could help stratify patients into high- or low-risk groups. The cell adhesion molecule P-selectin was recently identified as risk factor for VTE. To investigate soluble P-selectin (sP-selectin) in cancer patients as risk predictor for VTE, we performed a prospective cohort study of 687 cancer patients and followed them for a median (IQR) of 415 (221-722) days. Main tumor entities were malignancies of the breast (n = 125), lung (n = 86), gastrointestinal tract (n = 130), pancreas (n = 42), kidney (n = 19), prostate (n = 72), and brain (n = 80); 91 had hematologic malignancies; 42 had other tumors. VTE occurred in 44 (6.4%) patients. In multivariable analysis, elevated sP-selectin (cutoff level, 53.1 ng/mL, 75th percentile of study population) was a statistically significant risk factor for VTE after adjustment for age, sex, surgery, chemotherapy, and radiotherapy (hazard ratio = 2.6, 95% confidence interval, 1.4-4.9, P = .003). The cumulative probability of VTE after 6 months was 11.9% in patients with sP-selectin above and 3.7% in those below the 75th percentile (P = .002). High sP-selectin plasma levels independently predict VTE in cancer patients. Measurement of sP-selectin at diagnosis of cancer could help identify patients at increased risk for VTE.
Iron regulates phosphorylation of Smad1/5/8 and gene expression of Bmp6, Smad7, Id1, and Atoh8 in the mouse liver
Authors: Kautz Léon , Meynard Delphine , Monnier Annabelle , Darnaud Valérie , Bouvet Régis , Wang Rui-Hong , Deng Chiuxia , Vaulont Sophie , Mosser Jean , Coppin Hélène , Roth Marie-Paule
Published: June 2008

Although hepcidin expression was shown to be induced by the BMP/Smad signaling pathway, it is not yet known how iron regulates this pathway and what its exact molecular targets are. We therefore assessed genome-wide liver transcription profiles of mice of 2 genetic backgrounds fed iron-deficient, -balanced, or -enriched diets. Among 1419 transcripts significantly modulated by the dietary iron content, 4 were regulated similarly to the hepcidin genes Hamp1 and Hamp2. They are coding for Bmp6, Smad7, Id1, and Atoh8 all related to the Bmp/Smad pathway. As shown by Western blot analysis, variations in Bmp6 expression induced by the diet iron content have for functional consequence similar changes in Smad1/5/8 phosphorylation that leads to formation of heteromeric complexes with Smad4 and their translocation to the nucleus. Gene expression variations induced by secondary iron deficiency or iron overload were compared with those consecutive to Smad4 and Hamp1 deficiency. Iron overload developed by Smad4- and Hamp1-deficient mice also increased Bmp6 transcription. However, as shown by analysis of mice with liver-specific disruption of Smad4, activation of Smad7, Id1, and Atoh8 transcription by iron requires Smad4. This study points out molecules that appear to play a critical role in the control of systemic iron balance.
Differential effects of donor T-cell cytokines on outcome with continuous bortezomib administration after allogeneic bone marrow transplantation
Authors: Sun Kai , Li Minghui , Sayers Thomas J. , Welniak Lisbeth A. , Murphy William J.
Published: June 2008

Dissociating graft-versus-tumor (GVT) effect from acute graft-versus-host disease (GVHD) still remains a great challenge in allogeneic bone marrow transplantation (allo-BMT). Bortezomib, a proteasome inhibitor, has shown impressive efficacy as a single agent in patients with hematologic malignancies but can result in toxicity when administered late after allogeneic transplantation in murine models of GVHD. In the current study, the effects of T-cell subsets and their associated cytokines on the efficacy of bortezomib in murine allogeneic BMT were investigated. Increased levels of serum tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ) were observed after allo-BMT and continuous bortezomib administration. Bortezomib-induced GVHD-dependent mortality was preventable by depletion of CD4+ but not CD8+ T cells from the donor graft. The improved survival correlated with markedly reduced serum TNFα but not IFNγ levels. Transfer of Tnf−/− T cells also protected recipients from bortezomib-induced GVHD-dependent toxicity. Importantly, prolonged administration of bortezomib after transplantation of purified CD8+ T cells resulted in enhanced GVT response, which was dependent on donor CD8+ T cell–derived IFNγ. These results indicate that decreased toxicity and increased efficacy of bortezomib in murine allo-BMT can be achieved by removal of CD4+ T cells from the graft or by inhibiting TNFα.
A comparison of cold forming, hot forging, and induction bending as methods of producing duplex stainless steel elbows for high-pressure pipework
Authors: Collie G J , Black I
Published: June 2008

Two methods are commonly used to produce elbows for use in complex, high-pressure pipework: hot forging and cold forming. The former is expensive and produces an elbow that has an excessively thick wall section necessitating a large amount of preparation prior to fabrication welding. The thick wall sections also present a challenge for post-forming heat treatment and are a particular concern when the parent material is a duplex stainless steel as there is a risk that an intermetallic phase material will be formed. Cold forming is significantly less expensive and produces a finished product that requires much less preparation prior to welding; however, there are concerns regarding the acceptability of the metallurgy of the finished item. A third method of producing elbows, induction bending, is less frequently used and, while being disadvantaged by marked changes in wall section the finished elbow offers the prospect of a solution with similar cost and availability advantages to cold forming. This paper therefore briefly describes the three processes. It then compares the geometry, metallurgy, corrosion resistance, and mechanical properties of the products of each method, and commercial comparison is made. It is concluded that cold forming offers several distinct advantages over its rivals and it is recommended that this means of production be given favourable consideration by piping engineers when specifying elbows for complex subsea pipework.
The strain gradient approach for determination of forming limit stress and strain diagrams
Authors: Safikhani A R , Hashemi R , Assempour A
Published: June 2008

The forming limit stress diagram (FLSD) has been reported as being much less path dependent and much more favourable than the forming limit diagram (FLD) in representing forming limits in the numerical simulation of sheet metal forming processes. Therefore, the purpose of this study was to develop a methodology for the prediction of the forming limits both in strain and stress forms. All simulations are based on strain gradient theory of plasticity in conjunction with the Marciniak—Kuczynski (M—K) approach. This approach introduces an internal length scale into conventional constitutive equations and takes into account the effects of deformation inhomogeneity and material softening. The non-linear second-order ordinary differential equation of the thickness of sheet metal has been solved using the collocation method. It is shown that this method overcomes the imperfection sensitivity encountered in the conventional M—K method. An evaluation of the theoretical results is carried out. The comparison between the experimental and theoretical results for FLDs and FLSDs as predicted by different methods indicates that the present approach is suitable for these problems.
A practical approach to optimize the coating parameters to win customer confidence
Authors: Muthusamy N , Arunachalam V P , Balaji B
Published: June 2008

An investigation is carried out to find the near-optimum parametric combination of process variables in zinc coating with considerations of multiple performance characteristics to produce defect-free (such as peel-off, white shading, brightness, blistering, and decolouring) components. The Taguchi L36 (23X313) orthogonal array-based experiment design is used in this study to optimize process parameters. The significance and percentage contributions of each process variable are evaluated using the signal-to-noise (S/N) ratio, ANOVA, response curve, and significance test with Fstatic. Confirmation tests are conducted to see eye to eye on the quality and reliability of the component for winning customer confidence. The study infers that Taguchi off-line quality control is a correct method for optimizing coating process variables with a minimum number of trial runs as compared with the full factorial design in the traditional surface-coating process. The durability of the component in question is confirmed by means of salt-spray testing for aesthetic requirements.
Information supply: An approach based on demand modelling and information filtering
Authors: Zhen L , Jiang Z , Song H , Liu C , Liang J
Published: June 2008

Collaborative team members usually come from diverse disciplines; their demands for information are also different from each other. This paper is mainly concerned with how to capture designers’ demands for information in a collaborative team. From a workflow perspective, designers’ information demand is modelled considering three aspects: members’, roles’, and tasks’ requirements for information. Based on a static model of information demand and information filtering technologies, a dynamic model is proposed so that the designers’ information demand could be derived automatically. In addition, the appropriate volume of information for designers’ needs could also be determined intelligently. With the information demand model, an information supply system could be developed to realize the following objective: the delivery of an appropriate volume of information within an appropriate domain, delivered to the appropriate user in the collaborative team.
Simulation of three-dimensional free-form surface normal machining by 3SPS+RRPU and 2SPS+RRPRR parallel machine tools
Authors: Lu Y , Xu J-Y
Published: June 2008

A novel 5-degrees-of-freedom (DOF) 3SPS+RRPU parallel machine tool (PMT) and a novel 5-DOF 2SPS+RRPRR PMT are proposed for a three-dimensional (3D) free-form surface normal machining. A computer aided design (CAD) variation geometry approach is adopted for solving the extension/rotation of linear/rotational actuators and the pose of the two PMTs during machining. First, two simulation mechanisms are created by the CAD variation geometry technique for the 3SPS+RRPU PMT and the 2SPS+RRPRR PMT, respectively. Second, a 3D free-form surface and a guiding plane of tool path are constructed above the moving platform of the simulation mechanism. Third, the tool axis of the simulation PMT is kept normal to the 3D free-form surface, and two 5-DOF simulation PMTs are created. Finally, in the light of the two prescribed tool paths, the extension/rotation of linear/rotational actuators, and the pose of the PMTs are solved automatically and visualized dynamically.
The use of Taguchi and approximation methods to optimize the laser hybrid welding of a 5052-H32 aluminium alloy plate
Authors: Song C Y , Park Y W , Kim H R , Lee K Y , Lee J
Published: June 2008

This study aims to identify the optimal welding conditions for laser hybrid welding on a 5052-H32 aluminium alloy. Non-linear transient thermal analysis is adopted to simulate the thermo-physical phenomena in the welding process. Taguchi's parameter design method is applied to establish the optimal welding parameters that minimize residual stress and strain. The results obtained via design of experiments (DOE) and Taguchi's parameter design using the welding simulations are compared with the experimental results. Using DOE data, approximation models such as the polynomial-based response surface method and the radial basis function neural network are constructed. Using such approximation models, the relationship between welding conditions and thermo-mechanical responses can easily be estimated according to the parameter variations.
Design and testing of a novel interactive playground device
Authors: Hodgkins P , Caine M , Rothberg S , Spencer M , Mallison P
Published: June 2008

The concept of an interactive playground was born out of the specific need to tackle increasing levels of childhood obesity in the UK. A worryingly high proportion of children are inactive, preferring to spend their leisure time playing sedentary computer games or other electronic gaming devices. To engage this specific user group, an interactive, whole-body outdoor play device was devised. The device is intended to promote ‘stealth fitness’ with an aim to improve user's reaction time, coordination, agility, and cardiovascular fitness. This paper describes the design and experimentation phases undertaken to develop the device from an initial concept to a final product. Fifteen healthy children completed an experimental study consisting of three 5-min sessions. Heart rate was continuously monitored and ratings of enjoyment, competence, and perceived exertion were recorded after each session. The results indicate that using the new device elicits a large cardiovascular response while providing high levels of enjoyment.
A novel multi-objective particle swarm optimization algorithm for no-wait flow shop scheduling problems
Authors: Pan Q-K , Wang L , B Qian
Published: June 2008

The current paper presents a novel multi-objective particle swarm optimization (MOPSO) algorithm for solving no-wait flow shop scheduling problems with makespan and maximum tardiness criteria. First, in the algorithm, particles are represented as job permutations and updated directly in the discrete domain. Second, the concept of Pareto dominance is applied to compare different solutions of multi-objective optimization, and a set is employed to hold and to update the obtained non-dominated solutions, where a randomly selected non-dominated solution is assigned as the global best particle to maintain the diversity of the searching direction and to speed up the convergence process to the Pareto front. Third, a new multi-objective heuristic, named the PWQ (Pan—Wang—Qian) heuristic, is proposed to produce a population of initial particles with relatively good performances. Fourth, a simple but effective multi-objective local search algorithm is developed to embed in the MOPSO algorithm for stressing the balance between global exploration and local exploitation. In addition, two speed-up methods are devised to evaluate a job permutation and its insert neighbourhood respectively. Computational simulation results based on the well-known benchmarks and statistical performance comparisons are provided. It is shown that the proposed algorithm is superior to a recently published multi-objective hybrid differential evolution (MHDE) algorithm in terms of searching quality, diversity level, robustness, and efficiency.
A search for maximum efficiency and NOx reduction through spark-ignition engine design optimization at λ=1
Authors: Mehrani P , Watson H C
Published: June 2008

In this study a multizone model of spark-ignition engine combustion is validated and used to predict the thermal efficiency and NO x emissions of the engine. The model is validated against an engine map obtained from an extensive series of experiments. An optimizing algorithm based on particle swarm concepts is applied to the model to find a trade-off between efficiency and NO x emissions using a predefined cost function. Optimization is performed for three cases, each of which progressively includes more variables for optimization. A further constrained optimization case is performed with constant values of several of the variables set at the average values found in the three prior cases. These variables are the ones that change over a small domain. The results show the potential improvement in efficiency while achieving remarkably low NO x emissions. They emphasize the importance of exhaust gas recirculation (EGR) at high compression ratio and high loads when the maximum in-cylinder pressures are very high. They also suggest some strategies for valve timings that use internal EGR (residual gas) and move towards different compression and expansion ratios (Atkinson cycle).
Constrained H∞ control of active suspension for a half-car model with a time delay in control
Authors: Du H , Zhang N
Published: June 2008

The paper presents a new controller design approach for a four-degrees-of-freedom half-car suspension model considering the time delay in the control input. The time delay for the control input is assumed to be uncertain time invariant within a known constant bound. The ride comfort performance of the suspension system is optimized by using the H∞ norm to measure the body accelerations (including both the heaving and the pitching motions), while the tyre deflections and the suspension rattle spaces are constrained by their peak response values in time domain using the generalized H2 ( GH2) norm (energy-to-peak) performance. Then, a constrained delay-dependent H∞ state feedback controller is designed to realize the ride comfort, road holding and stroke limitation performance to prescribed level in spite of the existence of a time delay in control input. The design approach is formulated in terms of the feasibility of certain delay-dependent matrix inequalities. A numerical example is used to illustrate the effectiveness of the approach. It shows that the designed controller can keep the stability of the closed-loop system while improving the performance on ride comfort, keeping suspension strokes within given bounds, and ensuring firm contact of wheels to road even with the existence of a time delay in the control input to some extent.
Vehicle dynamics measurements
Authors: Pfeffer P E , Harrer M , Lin J
Published: June 2008

The modern vehicle development process relies evermore on the support of extensive subjective evaluation by objective vehicle dynamics measurements. Performing open-loop manoeuvres in conjunction with a steering robot greatly increases the reproducibility and eliminates influences caused by the driver. The obtained time data require considerable processing, in order to generate meaningful parameters, e.g. such as those defined in the ISO standards. The occurrence of time delay in the chain of measurements signals requires consideration in particular. Furthermore, the measured quantities must relate to a vehicle reference point. In the combined work of the BMW Group and the University of Bath, evaluation routines were developed, which significantly reduced the time spent on data processing by simultaneous improvement in the data quality. By employing these procedures, vehicle dynamics measurements were produced in a magnitude and to a quality previously unseen in the development process.
Optimal operation of the power-split hybrid electric vehicle powertrain
Authors: Ahn Kukhyun , Cho Sungtae , Cha Suk Won
Published: June 2008

A discussion on how to manage the hybrid electric vehicle powertrain is dealt with in this paper. An approach to analyse the optimal operation of a power-split hybrid electric vehicle is suggested on the basis of multi-objective optimization. A quasi-static powertrain model is developed and an entire space of operational choices is explored in order to find an attainable set of the optimal operation candidate group. Using this concept, two types of simulation are developed: the first simulation is based on the minimization of the equivalent fuel consumption and the latter simulation uses dynamic optimization. By analysing and comparing the results, choosing a single optimal operation point by minimizing the equivalent fuel consumption was found to give almost as high an energy efficiency as the theoretical maximum performance obtained by optimal control simulation. The results did not show a noticeable difference except in the case of high-power load conditions. From this analysis, a threshold is also proposed for vehicle operation in the pure electric vehicle mode.
Investigation of the grid and intake-generated tumble on the in-cylinder flow in a compression ignition direct-injection engine
Authors: Micklow G J , Gong W-D
Published: June 2008

The in-cylinder flow field was numerically investigated for a four-valve per cylinder Caterpillar diesel CAT3401 engine. The computer program used was the KIVA3V code developed by Los Alamos National Laboratory. To assess the effect of modelling assumptions made during the domain discretization, three grid models were developed. The first grid or the ‘complete’ grid was a full 360° mesh with moving valves, intake ports, exhaust ports, and runners. The second grid was a full 360° mesh without moving valves, intake ports, or exhaust ports. The third grid assumed that the in-cylinder flow field was periodic and a 60° mesh was generated to accommodate one of the six centrally located fuel injectors. It also neglected the valves and the intake and exhaust ports. The simplification of the grids is to reduce the massive computational and memory requirements to model these flows.

For the complete grid, the computation was initiated when the piston was at the top dead centre location on the intake stroke. For the second and third grids, the computation was initiated after the intake valve had closed. Complex three-dimensional vortical flow structures or tumble is developed during the intake stroke. These structures were clearly shown when the complete grid was used. By comparing the solution of the complete grid with the solutions of the second and third grids, it was seen that important in-cylinder flow information is lost. To overcome this deficiency, a new parameter, namely the initial tumble ratio, was embedded into the standard KIVA3V code by the present authors. When the simplified second grid is used in conjunction with the initial tumble ratio option, an in-cylinder flow pattern similar to that which was computed with the complete grid was obtained. This indicates that the new option significantly improves the accuracy of in-cylinder flow prediction when the moving valves and intake or exhaust ports are not modelled.

The effects of the values of the initial turbulence kinetic energy (TKEi) and the initial turbulence length scale (SCLi) were also studied. It is found that the suggested value of TKEi used in KIVA3V is too small to predict the actual turbulence kinetic energy in the cylinder when the second and third grids are used. Therefore, a larger value for TKEi is recommended. The effects of the different grids, the new initial tumble ratio, and the different values of SCLi and TKEi on important flow parameters, such as the swirl ratio, the tumble ratio, and the turbulence kinetic energy are compared in detail in this article.
Research and realization of optimum route planning in vehicle navigation systems based on a hybrid genetic algorithm
Authors: Hu L , Gu Z-Q , Huang J , Yang Y , Song X
Published: June 2008

An improved algorithm to solve the problem of optimum route planning in vehicle navigation systems is proposed in this paper. This algorithm is based on the standard genetic algorithm and the λ-interchange local search method and has evolved from the improved A shortest-path algorithm. This algorithm can find the optimum route more efficiently and quickly without any network constraint condition and can work well either in continuous or in discrete networks. Finally the experimental simulation results which verify the feasibility and validity of this algorithm are shown.
An optical method for automated roadside detection and counting of vehicle occupants
Authors: Tyrer J R , Lobo L M
Published: June 2008

The monitoring and control of traffic volume is becoming a constant social, economic, and environmental pressure in the UK and elsewhere, because of landmass and current infrastructure strain under a swelling and increasingly mobile population. The viability of high-occupancy vehicle (HOV) lanes for easing traffic congestion, and hence maximising traffic flow, has been proven in countries worldwide. The USA, Australia, and Canada have had HOV installations for some time, controlling the flux of traffic into their most densely populated areas. Experience in these cases has dictated that it is enforcement which is crucial to the successful implementation of such a traffic policy.

To date, all enforcement has been manual, i.e. a police officer counting the occupants in a vehicle as it passes by. Studies have concluded that manual enforcement is typically only 65 per cent accurate and, considering the pressures which one individual is put under in these circumstances, this statistic is not surprising. Lighting and environmental conditions, skin tone, and location of the occupants and the alertness of the officer are all variables affecting the accuracy of manually collected data. Hence there is the need for an autonomous detection system to count the occupancy within a vehicle. This could provide the basis of an enforcement or congestion strategy.
Design of the active hood lift system using orthogonal arrays
Authors: Shin M-K , Park K-T , Park G-J
Published: June 2008

The majority of pedestrian fatalities and injuries are caused by traffic accidents. Injuries of occupants in a vehicle have been considerably decreased due to many efforts by the industry. However, efforts for the protection of pedestrians still seem to be insufficient. Many industries are striving for better protection of pedestrians by using an active hood lift system, rather than reforming the existing structure. The active hood lift system lifts the hood when the vehicle hits a pedestrian, thus mitigating head injury to the pedestrian. In this research, the active hood lift system is designed to enhance the performance for protection. The active hood lift system is analysed by using the non-linear finite element method. Computer simulation is conducted for the impact between the headform and the hood. An optimization problem is formulated to incorporate the analysis results. An iterative optimization algorithm using orthogonal arrays is utilized for the design in a discrete space. The injury level to the head is significantly reduced in the newly designed product.
Comparing the steering performances of skid- and Ackermann-steered vehicles
Authors: Maclaurin B
Published: June 2008

Skid steering has advantages for military armoured vehicles because it gives greater internal hull volume and improved manoeuvrability. The steering performance of an 18t 6×6 skid-steered vehicle is analysed and compared with that of a similar Ackermann-steered vehicle. The basic properties of the double-differential mechanism used for steering most modern skid-steered vehicles are analysed. A tyre model is used that enables the force characteristics at combined slip to be established from the relatively small amount of pure slip data that are available for truck-sized tyres. A spreadsheet analysis is used for solving the equations of motion. This shows that the skid-steered vehicle is generally neutral to oversteer whereas the Ackermann-steered vehicle is understeer. The skid-steered vehicle is also shown to require more power when cornering because of the power required by the steering mechanism. This will increase the fuel consumption and reduce the range of the skid-steered vehicle.
A study on the reduction in pressure fluctuations for an independent pressure-control-type continuously variable transmission
Authors: Kim P , Ryu W-S , Kim H , Hwang S-H , Kim H-S
Published: June 2008

In this paper, the pressure characteristics for a metal belt-type independent pressure-control-type continuously variable transmission (CVT) are investigated, and a remedy to reduce the pressure fluctuations in the steady state is proposed. From the experiments, pressure fluctuations are observed for some secondary pressure range in the underdrive speed ratios. In order to analyse the pressure characteristics, dynamic models of the hydraulic control system including the CVT variator are obtained. Using the dynamic models, the parameters that affect the pressure fluctuations are investigated. From the simulations, it is found that the change in the hydraulic stiffness is the main reason for the pressure fluctuations. Based on the stiffness analysis, modification of the secondary control valve supply port notch is proposed to decrease the hydraulic stiffness gradient of the supply line from the secondary control valve to the CVT variator. From the simulation and the experiments, it is found that pressure fluctuations can be reduced effectively by this modification of the hydraulic stiffness.
Integral power management strategy for a complex hybrid electric vehicle — catering for the failure of an individual component
Authors: Zhang P-Z , Yin C-L , Zhang J-W , Chen L
Published: June 2008

A fault-tolerant function is critical for ensuring sufficient reliability and performance availability of control units in hybrid electric vehicles. For the purpose of providing a fault-tolerant system, a systematic integral power management strategy for a complex hybrid electric vehicle is presented at a system level. Once a subsystem component failure occurred, the hybrid vehicle system controller can take effective actions to achieve an acceptable performance. For instance, when the engine or battery fails to work, a limp-home operation is expected. Operational characteristics under normal modes and failure modes are discussed and a combined rule-based control strategy is developed to manage the power flow. Vehicle simulation integrated with a control algorithm is constructed and carried out in MATLAB/Simulink/Stateflow. Performances under normal and abnormal conditions are evaluated respectively.
On-board diagnosis of the drive circuit of an electronically controlled injector
Authors: Zhou X-L , Yu S-T , Mao X-J , Zhuo B , Feng J
Published: June 2008

On-board diagnosis regulations, drive safety, and facility of service require that the engine control unit must detect malfunctions of the electronically controlled fuel injection system. For injector drive circuit faults, there are two types of fault definition in the Society of Automotive Engineers J2012 regulation, it is not enough to satisfy the above requirements. Through analysing the feedback current and voltage of the drive circuit under faulty and no-fault conditions and abstracting fault symptoms, this paper extends further the range of on-board diagnosis strategies, including an open circuit, a high-side drive short circuit to the low-side drive, a high- (or low-)side drive short circuit to the power supply, and a high- (or low-) side drive short circuit to the ground. After the circuit fault is confirmed, the diagnosis strategy can trigger an appropriate failure strategy to guarantee safety and to avoid emissions deterioration. In order to enhance the diagnosis reliability, the key constants of the diagnosis strategies are calibrated using a statistical method.
Dynamic comparison of headlights
Authors: Serrat J , Diego F , Lumbreras F , Alvarez J M , Lopez A , Elvira C
Published: June 2008

Continuous innovations in automotive lighting technology pose the problem of how to assess new headlights systems. For car manufacturers, assessment is mostly relative: given a headlights system to be tested, how does it compare with another, maybe from a different supplier, in terms of features such as light intensity, homogeneity or reach? This comparison is best performed dynamically, asking experts actually to drive along a certain testing track to write down later the visual impressions that they remember. However, this procedure suffers from several drawbacks: comparisons cannot be repeated, are not retrospective, and cannot be properly shared with other people since the only record is a paper form. To overcome these, it is proposed to record, for each headlights system, a video sequence of what the driver sees with a camera attached to the windshield screen. The problem becomes now how to compare a pair of such sequences. Two issues must be addressed: the temporal alignment or synchronization of the two sequences, and then the spatial alignment or registration of all the corresponding frames. In this paper a semiautomatic but fast procedure for the former, and an automatic method for the later are proposed. In addition, an alternative to the joint visualization of corresponding frames called the bird's-eye view transform is explored, and a simple fusion technique for better visualization of the headlights differences in two sequences is proposed. Results are provided for a number of headlights with different light sources and from several vehicle brands, in the form of both still images and video sequences.
A finite-volume-based two-dimensional wall-flow diesel particulate filter regeneration model
Authors: Law M C , Clarke A , Garner C P , Williams A M
Published: June 2008

Many existing diesel particulate filter (DPF) models do not sufficiently describe the actual physiochemical processes that occur during the regeneration process. This is due to the various assumptions made in the models. To overcome this shortcoming, a detailed two-dimensional DPF regeneration model with a multistep chemical reaction scheme is presented. The model solves the variable density, multicomponent conservation equations by the pressure implicit with splitting of operators (PISO) scheme for inlet and outlet channels as well as the porous soot layer and filter wall. It includes a non-thermal equilibrium (NTE) model for the energy equation for porous media. In addition, for the first time, experiments on the DPF were conducted to determine the interstitial heat transfer coefficient inside the DPF porous wall. The results compare well with an in-house one-dimensional model and subsequently this was used in the new two-dimensional model. By using this detailed two-dimensional model, some interesting observations of the DPF regeneration process were revealed. These included flow reversals and asymmetry in the filter channels.
Metallic energy-absorbing inserts for Formula One tyre barriers
Authors: Guegan P , Lebreton D , Pasco F , Othman R , Le Corre S , Poitou A
Published: June 2008

Most Formula One circuits use tyre barriers for crash protection. Generally, they are composed of bolted tyres, fitted by a conveyor belt to the face of the barriers. The barriers are placed against a rigid wall or a metallic safety barrier. When the protection area is too small, the rigidity of the tyre barrier is improved by polyethylene tubular inserts inside the tyres. The static and dynamic tests realized at the Ecole Centrale de Nantes present the energy boundary condition for the thermoplastic insert used at present. Thus, contrary to what is usually thought, the following studies show that a metallic insert solution is better from an energy dissipation point of view.
Finite-time thermodynamic modelling and analysis of an irreversible diesel cycle
Authors: Ge Y-L , Chen L , Sun F-R
Published: June 2008

The performance of an air-standard diesel cycle is analysed using finite-time thermodynamics. An irreversible cycle model which is closer to practice is established. In the model, the non-linear relation between the specific heats of the working fluid and its temperature, the friction loss computed according to the mean velocity of the piston, the internal irreversibility described by using the compression and expansion efficiencies, and the heat transfer loss are considered. The relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, as well as the optimum relation between the power output and the efficiency of the cycle are derived by detailed numerical examples. Moreover, the effects of internal irreversibility, heat transfer loss, and friction loss on the cycle performance are analysed. The results obtained herein may provide guidance for the design of practical internal combustion diesel engine.
Measurement and prediction study of the effect of ethanol blending on the performance and pollutants emission of a four-stroke spark ignition engine
Authors: Al-Baghdadi M A R S
Published: June 2008

Considering the pollution problems and energy crisis today, investigations have been focused on lowering the concentration of toxic components in combustion products and decreasing fuel consumption by using renewable alternative fuels. The effects of ethanol addition to unleaded gasoline on the performance and pollutant emission of the spark ignition engine are established both analytically and experimentally. In the present work a quasi-dimensional model was developed to study the effect of ethanol blending on the thermodynamic cycle of the engine. The Ricardo E6/US engine has been used for verification and comparison of the results of the model with experimental tests. The results of the standard ASTM methods showed that, with increasing ethanol content, the research octane number of the blended fuels increases, while the Reid vapour pressure of the blended fuels initially increases to a maximum at 10vol% ethanol addition and then decreases. The results of the study showed that the addition of ethanol (from 0 to 30vol%) increases the engine power, thermal efficiency, and specific fuel consumption and reduces the nitrogen oxides, carbon monoxide, and hydrocarbon emissions. The ethanol added improves the combustion process, reduces the crevices flow energy, reduces the cylinder temperature, reduces the ignition delay, speeds up the flame front propagation, and reduces the combustion duration. The high useful compression ratio, which produced maximum engine power, was directly proportional to the ethanol percentage in the mixture.
Road test evaluation of vibration control performance of vehicle suspension featuring electrorheological shock absorbers
Authors: Sung K-G , Han Y-M , Sohn J W , Choi S-B
Published: June 2008

This work presents road test results for vibration control of a vehicle suspension system equipped with continuously controllable electrorheological (ER) shock absorbers. The test vehicle is a mid-sized passenger car whose suspension systems are typical Macpherson strut types for the front part and multilink types for the rear part. The four ER shock absorbers (two for the front suspension and two for the rear suspension) are devised based on design specifications for the test vehicle and their damping forces are experimentally evaluated with respect to the electric field. The ER shock absorbers and conventional spring elements are then assembled into suspension systems. Prior to undertaking the road test, the front ER suspension is applied to the quarter-car facility in order to validate control performance of the skyhook controller embedded in on-chip hardware. Subsequently, the full-vehicle model incorporating four ER suspensions is established and the skyhook control gains are determined in an optimal manner. The controller is then implemented on the test vehicle which is equipped with several sensors, a data acquisition system, and high-voltage amplifiers. Control performances are evaluated under various road conditions (bump, long waved, rugged, paved, and unpaved) and presented in both time and frequency domains.
Dynamic analysis of vehicles with uncertainty
Authors: Gao W , Zhang N , Ji J C , Du H P
Published: June 2008

The probabilistic and interval dynamic analysis of cars with uncertain parameters under random road input excitations by using a two-degree-of-freedom car model are presented in this paper. In the probabilistic analytical model, the vehicle parameters, including the sprung mass, unsprung mass, suspension damping, suspension, and tyre stiffness, are considered as random variables. The mean value, standard deviation, and variation coefficient of the vehicle's natural frequencies and mode shapes are obtained by using the Monte Carlo simulation method. Then, the computational expressions for the numerical characteristics of the mean square value of the vehicle's random response in the frequency domain are developed by means of the random variable's functional moment method. Considering the vehicle parameters as interval variables, the lower bound, upper bound, and interval change ratio value of the vehicle's random responses are obtained by means of the interval operations. The influences of the uncertainty of the vehicle parameters on the vehicle's natural frequencies, mode shapes, and dynamic responses are investigated in detail using a practical example. The comparison of the vehicle's dynamic characteristics using the probabilistic and interval analysis are also demonstrated.
Misconduct That ‘Has to Do with the Alleged Facts of the Offence with Which the Defendant is Charged’ … More or Less
Authors: Munday Roderick
Published: June 2008

Section 98(a) of the Criminal Justice Act 2003 exempts misconduct evidence that ‘has to do with the alleged facts of the offence with which the defendant is charged’ from the bad character rules that otherwise would govern its admissibility. The exception is far from precisely drafted and on a number of occasions the Court of Appeal has now had opportunity to consider the scope of application of this provision. This article critically analyses those decisions, and speculates on themes that in the future may play a role in the interpretation of s. 98(a).
Prevention of Harm—Legislative Strategies for Law Reform
Authors: Wade Clare
Published: June 2008

This article looks at the development of preventative civil measures with criminal sanctions and the ways in which they are influencing criminal law. It argues that serious crime prevention orders in Part 1 of the Serious Crime Act 2007 are a part of this trend and further, that they undermine traditional notions of due process. The provisions of Part 1 of the Serious Crime Act 2007 are contrasted with Part 2 of the Act. The article also argues that the new inchoate offence of encouraging and assisting crime and the Law Commission proposals for conspiracy will provide sufficient measures against future harm therefore obviating the need for civil preventative orders.
Can Touching Always Be Sexual When There is No Sexual Intent?
Authors: Bantekas Ilias
Published: June 2008

The objective test introduced by the Sexual Offences Act 2003 as to the sexual nature of the touching that constitutes sexual assault can lead to injustices, particularly where the defendant exposed the victim to nudity without intending—or being reckless-that his or her act assume a sexual character. To hold otherwise is tantamount to imposing strict liability, which was not intended by Parliament. The courts must assess each case on its merits and differentiate all those cases involving an element of moral involuntariness from those that do not. Equally, the courts should, where appropriate, permit the defence of necessity where the defendant did not intend, but was not negligent, as to the sexual nature of his act.
How to Measure the Diagnostic Accuracy of Noninvasive Liver Fibrosis Indices: The Area Under the ROC Curve Revisited
Authors: Lambert Jerome , Halfon Philippe , Penaranda Guillaume , Bedossa Pierre , Cacoub Patrice , Carrat Fabrice
Published: June 2008

Background: The area under the ROC curve (AUC) is widely used to measure the diagnostic accuracy of noninvasive fibrosis indices. However, use of the AUC assumes a binary gold standard, whereas fibrosis staging is based on an ordinal scale and also depends on the distribution of fibrosis stages in the study sample. We explored other fibrosis staging accuracy measures designed for ordinal gold standards, the C-statistic and the Obuchowski measure.

Methods: We performed a simulation study to assess the bias in estimating the accuracy measures when the distribution of fibrosis stages in the study sample do not fit the reference distribution in the population to which the indices are applied. We also estimated the type I error of the tests comparing these measures in 2 samples with different distributions of fibrosis stages. We illustrated the practical use of these measures by reanalyzing real data.

Results: Compared with the AUC or the C-statistic, the Obuchowski measure showed limited bias when the distribution of fibrosis stages in the study sample differed from the reference distribution. The type I error was strongly inflated with the AUC or the C-statistic but was preserved in the Obuchowski measure. When we compared noninvasive indices on real data, AUC analysis led to discordant results depending on how the fibrosis stages were grouped together. One single conclusion was drawn from the analysis based on the Obuchowski measure.

Conclusions: We recommend using the Obuchowski measure for assessing the diagnostic accuracy of noninvasive indices of fibrosis.
Commutable Calibrator with Value Assigned by the IFCC Reference Procedure to Harmonize Serum Lactate Dehydrogenase Activity Results Measured by 2 Different Methods
Authors: Cattozzo Giampaolo , Guerra Elena , Ceriotti Ferruccio , Franzini Carlo ,   the Enzyme Working Group of the Italian Society of Clinical Biochemistry and Clinical Molecular Biology (SIBioC)
Published: June 2008

Background: The availability of commutable calibrator materials may ease considerably the task of harmonizing assay results and ensuring their traceability to reference procedures. We sought to verify the commutability of potential calibrator materials and evaluate their effectiveness in harmonizing LDH results by 2 measurement methods.

Methods: We measured LDH in 109 serum samples and 31 materials, including frozen serum pools (with either normal or abnormal isoenzyme patterns), commercial stabilized materials, and the ERM-AD453/IFCC reference material. We assayed LDH activity with the IFCC reference procedure and with 2 commercial methods, 1 using the lactate-to-pyruvate (LP) reaction, and the other the pyruvate-to-lactate (PL) reaction. We selected a commutable material, with LDH value assigned by the reference procedure, as a calibrator for recalculating the results for patient sera by both LP and PL, thereby making them traceable to the IFCC reference procedure.

Results: Original values for patient sera (n = 109) by the 2 commercial methods showed a mean (SD) PL/LP ratio of 1.97 (0.03); this ratio changed to 1.06 (0.02) after recalculation of results. Linear regression of PL vs LP recalibrated values gave y = 1.108x – 9.7. At the clinically important concentration of 250 U/L (upper reference limit), the systematic difference between methods was 6.8%, which met our proposed quality specifications for inaccuracy and total error.

Conclusions: By properly selecting the calibrator, the results of serum LDH measurement by 2 different methods may be harmonized and made traceable to the selected highest (reference) metrological level.