bluuebunny/crossref_metadata_2025_split huggingface dataset:
On Aerodynamic Modelling and Simulation of the Dynamic Interface
Authors: Zan S J 
Published: November 2005

The past decade has seen significant advancements in modelling and simulation of the dynamic interface. The goal of the initial work in this area was to reduce the costs associated with first-of-class flight trials, and to deal with the backlog of aircraft-ship combinations for which flight-clearance envelopes were minimal or non-existent. A decade ago, piloted simulation of the dynamic interface appeared to be the obvious way to overcome these deficiencies. Validated models of fixed-wing and rotorcraft were in existence, and work began to combine these models with prescribed weather/lighting conditions (wind, rain, snow, fog, night, etc.), ship visuals, and motion. It had been envisioned that through the use of high-fidelity flight simulation, a test pilot could rapidly and safely determine the flight envelope boundaries without resorting to, or at least minimizing, flight trials. During the past decade, significant advancements in simulation fidelity did transpire due to increased computational power, an improved understanding of airwakes, and enhanced simulation capabilities. The article describes some of the fundamental and applied research that contributed to the improved fidelity, much of it gained in a collaborative fashion. To date, modelling and simulation technologies have not advanced to the state where they can replace flight tests to derive flight-clearance envelopes, but they have approached the point where they can augment flight tests and serve in a training capacity. The accrual of a training benefit has recently emerged and is a significant, though unplanned, dividend from the efforts directed towards flight-envelope prediction. This article sets out to examine some of the strengths and deficiencies of the current capabilities, and provides a discussion of the way forward. Modelling and simulation of the dynamic interface are discussed in a broad context, wherein they are defined to include non-piloted, non-real-time activities. The article will provide a critical review of many of these efforts to date, focusing primarily on aerodynamic issues. The article also discusses the challenges which are present for rotary-wing operations, for both small and large ships. It compares the environment in both cases and how that impacts the simulation requirements.
Quantification and Prediction of Pilot Workload in the Helicopter/Ship Dynamic Interface
Authors: Bradley R , Macdonald C A , Buggy T W 
Published: November 2005

The evaluation, early in the design cycle, of the limits for operating aircraft from ships in a wide range of sea states and atmospheric conditions has become an important issue for two main reasons. First, the simultaneous entry into service of new helicopter types and new naval platforms has generated an enormous task in the development of appropriate Ship Helicopter Operating Limits for in-service operations. Second, it has become clear that such operational factors need to be addressed at the design stage - which of necessity involves developing a predictive capacity in all of the areas which influence operational capability. These considerations need to take place in the context of technological advances which seek to assist the pilot in operations from ships. Improved radar for ship approaches and enhanced cueing, located around hangars and landing spots, are both areas which are being continually developed in association with upgraded aircraft systems for guidance, control, and stability augmentation. Ultimately, however, the situation comes down to the pilot's assessment of the workload involved in any task and the handling qualities of the vehicle being controlled. For this reason there has been a growing interest in two related areas: (i) the development of metrics to provide a consistent indicator of pilot workload and (ii) the enhancement of existing pilot models to generate authentic control activity in the aircraft/ship dynamic interface. This article describes recent techniques for extracting workload metrics from control activity and indicates the extent to which acceptably accurate workload predictions can be made. Some advances in pilot modelling are also described and examples are given to demonstrate the capability and limitations of currently available methods. Finally, the present state of integration of the two aspects into a robust tool for ship and aircraft system design is discussed. The focus of this article is, of necessity, on helicopter operations because that is where most of the current work has been centred.
Bond Graph Modelling for Non-Linear Hydro-Mechanical Systems
Authors: Margolis D , Shim T 
Published: November 2005

Bond graphs are a concise pictorial representation of the interactive dynamics of all types of engineering systems. Relatively few symbols are needed to represent these systems, and this includes non-linear mechanics interacting with hydraulic or pneumatic subsystems. Agricultural and construction equipments and vehicles are examples of such complex systems. Assembling overall system models of such complex systems can be very difficult without a unifying procedure that indicates computational causality as the model is developed. Bond graphs allow for the continuous assessment of causality as a model is developed, regardless of the non-linearity of the individual pieces. This causality indicates computational problems and allows the modeller to address these problems prior to deriving equations or attempting to simulate the system. The development of such models is done here as generally as possible, but is applied to an unstable backhoe as an example. The systematic modelling procedures of a backhoe are used for the development of individual subsystems which are then combined into an overall computational model.
Simulation of Motor-Scooter Drop Testing by a Multi-Body Finite Element Integrated Approach
Authors: Frendo F 
Published: November 2005

The drop test is employed in the motor-scooter industry for evaluating the frame performance under particularly severe conditions. In this work, a numerical procedure developed for simulating the test is presented. The procedure includes a multi-body model for the evaluation of the maximum loads acting on the scooter frame during impact at ground. Such loads were then employed in a non-linear static finite element analysis in order to obtain the permanent frame deformation. The experimental activity carried out for vehicle characterization and the experimental apparatus set up for tests are also presented in detail. The multi-code approach appeared versatile and straightforward, and furnished results in satisfactory agreement with experiments.
Modelling Commercial Vehicle Handling and Rolling Stability
Authors: Hussain K , Stein W , Day A J 
Published: November 2005

This paper presents a multi-degrees-of-freedom non-linear multibody dynamic model of a three-axle heavy commercial vehicle tractor unit, comprising a subchassis, front and rear leaf spring suspensions, steering system, and ten wheels/tyres, with a semi-trailer comprising two axles and eight wheels/tyres. The investigation is mainly concerned with the rollover stability of the articulated vehicle. The models incorporate all sources of compliance, stiffness, and damping, all with non-linear characteristics, and are constructed and simulated using automatic dynamic analysis of mechanical systems formulation. A constant radius turn test and a single lane change test (according to the ISO Standard) are simulated. The constant radius turn test shows the understeer behaviour of the vehicle, and the single lane change manoeuvre was conducted to show the transient behaviour of the vehicle. Non-stable roll and yaw behaviour of the vehicle is predicted at test speeds >90 km/h. Rollover stability of the vehicle is also investigated using a constant radius turn test with increasing speed. The articulated laden vehicle model predicted increased understeer behaviour, due to higher load acting on the wheels of the middle and rear axles of the tractor and the influence of the semi-trailer, as shown by the reduced yaw rate and the steering angle variation during the constant radius turn. The rollover test predicted a critical lateral acceleration value where complete rollover occurs. Unstable behaviour of the articulated vehicle is also predicted in the single lane change manoeuvre.
Pseudo-Dynamic Method for Structural Analysis of Automobile Seats
Authors: Carneiro J O , de Melo F J Q , Pereira J T , Teixeira V 
Published: November 2005

This work describes the application of a pseudo-dynamic (PsD) method to the dynamic analysis of passenger seats for the automotive industry. The project of such components involves a structural test considering the action of dynamic forces arising from a crash scenario. The laboratory certification of these automotive components consists essentially on the inspection of the propagation and extension of plastic deformations zones in metallic members of the seat structure as consequence of the mutual action between the seat and the passenger fastened to the seat via seat belt anchorages. This work presents a relatively simple experiment using PsD techniques as a novel method to perform a test equivalent to the dynamic model of a dummy-seat pair subjected to impulsive loads from a car crash. Essentially, the PsD test method is a hybrid and hierarchic computer-driven testing procedure where a numerical algorithm and experimental step are used and combined on-line in order to solve a problem in the scope of structural dynamics. The implementation of the method is not expensive and has the leading advantage of offering the operator a total control of any intermediate structure state during the test still keeping the realism of a real dynamic testing.
Container Gantry Crane Simulator for Operator Training
Authors: Rouvinen A , Lehtinen T , Korkealaakso P 
Published: November 2005

Real-time simulators have become more popular in the field of user training. This is due to the possibility to give basic training and knowledge of machines and their operation environment to the operator even when the machine is not actually present. The use of simulators instead of actual machines has several advantages. First of all, the available machine capacity is not tied to training and can be used in productive work. Secondly, using a simulator helps to avoid accidents that may occur using real machines. Using a simulator also enables different environmental aspects, such as lighting conditions, fog, wind, and so on, to be taken into account in the training of all operators alike. Real-time training simulators are complicated machine systems, which consist of a user interface, an I/O-system, a real-time simulation model describing the dynamics of the machine in question and its connections to the environment, a visualization of the operational environment, and a possible motion platform. The user interface is usually taken directly from the simulated machine. Consequently, the user has the possibility to become familiar with the operating interface in an early phase of training. In this article, the development of a gantry crane operator-training simulator, including all the earlier mentioned components, is presented. The aim of this article is to present an example of methods used in the development of the separate areas of a training simulator.
Choice of drainage procedure in paediatric pyopericardium: a 30-year experience
Authors: Hayavadana Rao P V , Raveenthiran V 
Published: November 2005

Although there is general agreement on the necessity of draining pyopericardium, debate continues as to the safe and effective method of drainage. Studies describing head-to-head comparison of various drainage procedures are very few and are disadvantaged by small numbers of cases. In this observational study, we review our 30-years experience with different techniques of pericardial drainage. Between 1972 and 2003, the authors have personally treated 39 children who suffered from pyopericardium. Among the 22 children who underwent early partial pericardiectomy, 20 were alive. In contrast to this,12 out of 15 children treated with repeated pericardiocentesis or sub-xiphoid tube drainage were dead. The median hospital stay for pericardiectomy group was 18 days (range 11-32) and that for the non-thoracotomy group was 34 days (range 18-55 days). With regard to immediate survival and early convalescence in the pyopericardium, partial pericardiectomy is superior to pericardiocentesis and sub-xiphoid tube drainage. Pericardiocentesis can be used for diagnostic or temporizing purposes, but not as the definitive drainage procedure. Partial pericardiectomy can be done even in small hospitals where heart-lung machines are not available.
Drug use among adolescents in Ilorin, Nigeria
Authors: Abdulkarim A A , Mokuolu O A , Adeniyi A 
Published: November 2005

The types and frequency of drug use among 1200 students aged 10-19 years was investigated and a prevalence rate of 40.1% found; currently used drugs included mild stimulants such as kolanut and coffee 294 (26.2%), alcohol 164 (14.5%), sniffing agents 80 (7.2%), amphetamine and ephedrine 66 (6.7%), cigarette 54 (4.8%), heroin 45 (4%) cocaine 40 (3.6%) and cannabis 38 (3.4%). Multiple drug use was found among the students, with the abuse of cannabis, cocaine and heroin being significant among those who smoked cigarette ( P<0.001). The relative risk (RR) for cannabis use when cigarette was smoked was 37.4 (24.1-57.8); RR for cigarette smoking when alcohol was used, 6.8, while RR for cocaine abuse when cigarette was used, 21.8 (13.9-34.5) and 52.8 (29.2-95.5) when cannabis was used. It is therefore concluded that the use of the licit and 'socially' acceptable drugs may pave the way for the abuse of illicit ones.
Sexual risk behaviour among young people in Osogbo, Osun state Nigeria
Authors: Mabayoje V O , Akinwusi P O , Fadiora S O , Adeyeba O A , Aderounmu A O , Ebgewale E B 
Published: November 2005

By analysing data randomly collected via administration of questionnaire by interview of individuals on sexual risk behaviour to 628 young people living in Osogbo, Nigeria, the results of the questionnaire revealed that the mean age of first sexual encounter was 17.4 years for men and 16.5 years for women. Men tended to have multiple sexual partners more than the women (74.4% and 25.1%, respectively), while there was a highly significant relationship between sexually transmitted disease and multiple sexual partners among singles with P<0.001 and P= 0.000. We concluded that parents and government alike should teach sex education at home, and in schools involving intensive counselling.
Comparison of three different combination therapies in the treatment of human brucellosis
Authors: Ersoy Yasemin , Sonmez Emine , Tevfik Mehmet R , But Aype Dinç 
Published: November 2005

The efficacy and tolerability of three different combination treatment regimens in human brucellosis were compared in 118 uncomplicated patients enrolled in a prospective study between May 1997 and December 2002. Brucellosis was diagnosed using standard clinical and microbiological findings. Patients with central nervous system involvement, spondylitis, endocarditis or children under 16 years of age were excluded from the study. Patients were randomly assigned to receive 400 mg of ofloxacin plus 600 mg of rifampicin (OR, n = 41), 200 mg of doxycycline plus 600 mg of rifampicin (DR, n = 45) or 1g intramuscularly streptomycin (administered for three weeks) plus 200 mg doxycycline (DS, n = 32) daily for 6 weeks. All patients were followed up at least 6 months after cessation of therapy. There was no statistical difference between the groups on relapse rates and clinical response to the treatment ( P>0.05). Five patients in OR (12.8%), six patients in DR (14.3%) and three patients in DS groups (9.7%) suffered relapse. The side-effects were seen in eight (19.5%), 21 (46.7%) and eight (25.0%) patients of OR, DR and DS groups, respectively. The use of combination therapy of ofloxacin plus rifampicin for 6 weeks was found to be as effective as DR and DS. The side-effects of therapy in OR and DS groups was less severe than in the DR group.
Causes of the decline in AIDS deaths, United States, 1995–2002: prevention, treatment or both?
Authors: Holtgrave David R 
Published: December 2005

The decline in AIDS deaths in the USA between 1995 and 2002 has been attributed by Centers for Disease Control (CDC) to HIV treatments advances. The purpose of the present study is to assess whether this AIDS deaths decline was due entirely to treatment advances, to earlier prevention successes, or a combination of both. Secondarily, we quantitatively estimate the number of AIDS deaths averted (or delayed) by treatment advances over and above prevention effects. The study employed scenario analysis to address the research questions. To answer the primary research question, we examined whether three key predictions derived from the shape and peak of the HIV incidence curve in the USA (and the natural history of HIV disease in the era before highly active antiretroviral therapy [HAART]) about the shape and peak of the AIDS deaths curve were upheld (e.g., one prediction was that the peak of the AIDS deaths curve should occur 10–12 years after the peak of the HIV incidence curve). To the extent that these predictions are supported, there is evidence that earlier HIV prevention efforts impacted the number of AIDS deaths later in the epidemic. To answer the second research question, the observed annual AIDS deaths curve (1995–2002) was compared with three estimated AIDS deaths curves that may have occurred had HAART never became available. Three estimations were employed to reflect a range of assumptions about the lag between the flattening of HIV incidence in the USA and the flattening of AIDS deaths (i.e., 10, 11 or 12 years). For any one of the three-scenario analyses, the quantitative area between the 'observed' and 'estimated' AIDS deaths curves provide an estimate of the number of AIDS deaths averted by HIV/AIDS treatments. The three predictions from the HIV incidence curve (and the pre-HAART natural history of HIV disease) for determining the shape and peak of the AIDS deaths curve were supported thereby indicating the influence of past prevention efforts on recent AIDS deaths. However, the observed decline in AIDS deaths was more precipitous than predicted (indicating the influence of treatment advances). The scenario analyses indicated that between 33,480 and 41,784 AIDS deaths were averted (or delayed) between 1995 and 2002 as a function of treatment. That is, approximately, 206,037 AIDS deaths occurred between 1995 and 2002 (in the HAART era), but between 239,517 and 247,821 likely would have occurred without the advent of HAART. We conclude that both past prevention and current treatment services have lead to the AIDS deaths decline in the USA, and that HAART has averted between 33,480 and 41,784 AIDS deaths in the USA between 1995 and 2002 over and above the effects of early prevention efforts.
The HND mouse, a nonobese model of type 2 diabetes mellitus with impaired insulin secretion
Authors: Horio Fumihiko , Teradaira Shin , Imamura Tsunehiko , Anunciado Rea Victoria P , Kobayashi Misato , Namikawa Takao , Niki Ichiro 
Published: December 2005

Objectives: This study aimed to develop a novel type 2 diabetes model designated the HND (Horio–Niki diabetic) mouse, by transferring diabetogenic genes from wild castaneus mice (Mus musculus castaneus) captured in the Philippines into laboratory mice (C57BL/6J:B6).
Methods: Offspring from the cross between a wild male and a B6 female were backcrossed to the sire. One male backcross which exhibited fasting hyperglycemia was crossed with a B6 female to comprise the fundamental stock (F0). Thereafter, full-sib mating was performed, and mice with impaired glucose tolerance were selected and bred from the F2 generation. Characterization of the phenotype of HND mice and insulin release from their islets was evaluated with F12 generation males.
Results: The male HND mice were lean, and spontaneously exhibited impaired glucose tolerance at a high incidence rate at 6 weeks of age. Their serum insulin levels in response to intraperitoneal glucose were markedly attenuated. However, glucose-induced insulin release from isolated HND islets was not affected. Notably, inhibition of glucose-induced insulin release by epinephrine was more pronounced in HND islets than in B6 islets. Moreover, in vivo treatment of HND mice with the α2-adrenergic receptor agonist clonidine resulted in marked hypoinsulinemic hyperglycemia.
Conclusions: We suggest the HND mouse may be a distinctive and useful model for type 2 diabetes with impaired neural control of insulin secretion.
Clinical and psychological correlates of quality-of-life in polycystic ovary syndrome
Authors: Hahn Susanne , Janssen Onno E , Tan Susanne , Pleger Katja , Mann Klaus , Schedlowski Manfred , Kimmig Rainer , Benson Sven , Balamitsa Efthimia , Elsenbruch Sigrid 
Published: December 2005

Objective: Polycystic ovary syndrome (PCOS) has been shown to cause a reduction in quality of life. This study examines the extent of different PCOS symptoms on quality-of-life, psychosocial well-being and sexual satisfaction.
Methods: Complete metabolic, hormonal, clinical and psychosocial data were obtained from a total of 120 women with PCOS. Patients were compared with 50 healthy women to establish reductions in quality-of-life and emotional well-being. In addition, the correlation between psychosocial variables and the major clinical PCOS features obesity (body mass index (BMI)), excessive body hair (hirsutism score), acne, hyperandrogenism (serum testosterone levels), disturbed insulin regulation (area under the insulin response curve and homeostasis model assessment of insulin resistance), menstrual cycle disturbances and infertility were analyzed.
Results: PCOS patients showed significant reductions in quality-of-life, increased psychological disturbances, and decreased sexual satisfaction when compared with healthy controls. BMI and hirsutism scores, but not the presence of acne, were associated with physical aspects of quality-of-life and sexual satisfaction. No clear effect of androgens or insulin resistance on psychosocial variables was detected. Similarly, the type of menstrual cycle disturbances or infertility had no impact on psychological well-being.
Conclusion: In PCOS, changes in appearance, particularly obesity and hirsutism, reduce physical dimensions of quality-of-life and decrease sexual satisfaction. The role of biochemical, endocrine and metabolic parameters as well as menstrual irregularities and infertility appeared to be less important. Clinicians should pay attention to the psychosocial dimensions of PCOS on an individual basis, regardless of symptom severity or treatment response.