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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Modelling income, wealth, and expenditure data by use of Econophysics

Oltean, Elvis January 2016 (has links)
In the present paper, we identify several distributions from Physics and study their applicability to phenomena such as distribution of income, wealth, and expenditure. Firstly, we apply logistic distribution to these data and we find that it fits very well the annual data for the entire income interval including for upper income segment of population. Secondly, we apply Fermi-Dirac distribution to these data. We seek to explain possible correlations and analogies between economic systems and statistical thermodynamics systems. We try to explain their behaviour and properties when we correlate physical variables with macroeconomic aggregates and indicators. Then we draw some analogies between parameters of the Fermi-Dirac distribution and macroeconomic variables. Thirdly, as complex systems are modelled using polynomial distributions, we apply polynomials to the annual sets of data and we find that it fits very well also the entire income interval. Fourthly, we develop a new methodology to approach dynamically the income, wealth, and expenditure distribution similarly with dynamical complex systems. This methodology was applied to different time intervals consisting of consecutive years up to 35 years. Finally, we develop a mathematical model based on a Hamiltonian that maximises utility function applied to Ramsey model using Fermi-Dirac and polynomial utility functions. We find some theoretical connections with time preference theory. We apply these distributions to a large pool of data from countries with different levels of development, using different methods for calculation of income, wealth, and expenditure.
12

Application of Java on Statistics Education

Tsay, Yuh-Chyuan 24 July 2000 (has links)
With the prevalence of internet, it is gradually becoming a trend to use the network as a tool of computer-added education. However, it is used to present the computer-added education with static state of the word, but it is just convenient to read for the user and there are no difference with traditional textbook. As the growing up of WWW and the development of Java, the interactive computer-added education is becoming a trend in the future and it can promote the effect of teaching basic statistics with the application of this new media. The instructor can take advantage of HTML by combining with Java Applets to achieve the display of interactive education through WWW. In this paper, we will use six examples of Java Applets about statistical computer-added education to help student easily to learn and to understand some abstract statistical concepts. The key methods to reach the goal are visualization and simulation with the display of graphics or games. Finally, we will discuss how to use the Applets and how to add the Java Applets into your homepage easily.
13

Application of Java on Mathematical Statistics Education

Su, Yi-Che 20 June 2001 (has links)
In the recent years, the internet has been developed rapidly. By this convenient medium, the information can be spread easily all over the world. Using the convenience and variety of internet, e-learning has become a burgeoning and efficient way for learning. The main idea of e-learning is applying the concept of Asynchronous Course Delivery, and establishing a learning environment on the internet. With the connection between computer and the internet, user can learn more in a convenient environment. In order to apply the concept of e-learning to the course of statistics, we use the Java programming language to establish an on-line interactive environment. In addition to learn some fundamental concepts of statistics, learner can also strengthen the abilities of researching and surfing by themselves. In this paper we developed six interactive examples. Not only interpreting and illustrating, we also introduce the motive, goal, relative concepts and applications in detail for each example. Finally, we hope that user can easily learn more knowledge of statistics by this learning environment, then our e-learning to statistical education, can be achieved.
14

PERFORMANCE ENHANCEMENT OF OFDM IN PAPR REDUCTION USING NEW COMPANDING TRANSFORM AND ADAPTIVE AC EXTENSION ALGORITHM FOR NEXT GENERATION NETWORKSPERFORMANCE ENHANCEMENT OF OFDM IN PAPR REDUCTION USING NEW COMPANDING TRANSFORM AND ADAPTIVE AC EXTENSION ALGORITHM FOR NEXT GENERATION NETWORKS

BAIG, CLEMENT RANJITH ANTHIKKAD & IRFAN AHMED January 2013 (has links)
This paper presents a new hybrid PAPR reduction technique for the OFDM signal, which combines a multiple symbol representations method with a signal clipping method. The clipping method is a nonlinear PAPR reduction scheme, where the amplitude of the signal is limited to a given threshold. Considering the fact that the signal must be interpolated before A/D conversion, a variety of clipping methods has been proposed. Some methods suggest the clipping before interpolation, having the disadvantage of the peaks re-growth. Other methods contributed that the clipping after interpolation, having the disadvantage of out-of-band power production. In order to overcome this problem different filtering techniques have been proposed. Filtering can also cause peak re-growth, but less than the clipping before interpolation. Another clipping technique supposes that only subcarriers having the highest phase difference between the original signal and its clipped variant will be changed. This is the case of the partial clipping method. To further reduce the PAPR, the dynamic of the clipped signal can be compressed. Linear methods like partial transmit sequence or selective mapping has been proposed for the reduction of PAPR as well. Another PAPR reduction method is the tone reservation. It uses tones on which no data is sent to reduce the transmitted signal peaks. Derivatives of this method with lower computation complexity and improved performance have been proposed: One-Tone One-Peak and one by-one iteration. A similar PAPR reduction method is the multiple symbol representations, where alternative signalling points are used to represent one symbol. The simulation results highlight the advantages of the proposed PAPR reduction method. / The proposed technique namely Adaptive Active Constellation Extension (Adaptive ACE) Algorithm reduced the high Peak-to-Average Power Ratio (PAPR) of the Orthogonal Frequency Division Multiplexing (OFDM) systems. The Peak-to-Average Power Ratio (PAPR) is equal to 6.8 dB for the target clipping ratios of 4 dB, 2 dB and 0 dB by using Adaptive Active Constellation Extension (Adaptive ACE) Algorithm. Thus, the minimum PAPR can be achieved for low target clipping ratios. The Signal-to-Noise Ratio (SNR) of the Orthogonal Frequency Division Multiplexing (OFDM) signal obtained by the Adaptive Active Constellation Extension (Adaptive ACE) algorithm is equal to 1.2 dB at a Bit Error Rate (BER) of 10-0..4 for different constellation orders like 4-Quadrature Amplitude Modulation (4-QAM), 16-Quadrature Amplitude Modulation (16-QAM) and 64-Quadrature Amplitude Modulation (16-QAM). Here, the Bit Error Rate of 10-0.4 or 0.398, that means a total of 398-bits are in error when 1000-bits are transmitted via a communication channel or approximately 4-bits are in error when 10-bits are transmitted via a communication channel, which is high when compared to that of the original Orthogonal Frequency Division Multiplexing (OFDM) signal. The other problems faced by the Adaptive Active Constellation Extension (Adaptive ACE) algorithm are Out-of-Band Interference (OBI) and peak regrowth. Here, the Out-of-Band Interference (OBI) is a form of noise or an unwanted signal, which is caused when the original Orthogonal Frequency Division Multiplexing (OFDM) signal is clipped for reducing the peak signals which are outside of the predetermined area and the peak regrowth is obtained after filtering the clipped signal. The peak regrowth results to, increase in the computational time and computational complexity. In this paper, we have proposed a PAPR reduction scheme to improve the bit error rate performance by applying companding transform technique. Hence, 1-1.5 dB reduction in PAPR with this Non-companding technique is achieved. In Future, We can accept to implement the same on Rician and Rayleigh channels. / Clement Ranjith Anthikkad (E-mail: clement.ranjith@gmail.com / clan11@bth.se) & Irfan Ahmed Baig (E-mail: baig.irfanahmed@gmail.com / ir-a11@bth.se )
15

An offset modulation method used to control the PAPR of an OFDM transmission

Dhuness, Kahesh 14 August 2012 (has links)
Orthogonal frequency division multiplexing (OFDM) has become a very popular method for high-data-rate communication. However, it is well known that OFDM is plagued by a large peak-to-average power ratio (PAPR) problem. This high PAPR results in overdesigned power amplifiers, which amongst other things leads to inefficient amplifier usage, which is undesirable. Various methods have been recommended to reduce the PAPR of an OFDM transmission; however, all these methods result in a number of drawbacks. In this thesis, a novel method called offset modulation (OM-OFDM) is proposed to control the PAPR of an OFDM signal. The proposed OM-OFDM method does not result in a number of the drawbacks being experienced by current methods in the field. The theoretical bandwidth occupancy and theoretical bit error rate (BER) expression for an OM-OFDM transmission is derived. A newly applied power performance decision metric is also introduced, which can be utilised throughout the PAPR field, in order to compare various methods. The proposed OM-OFDM method appears to be similar to a well-known constant envelope OFDM (CE-OFDM) transmission. The modulation, structural and performance differences between an OM-OFDM and a CE-OFDM method are discussed. By applying the power performance decision metric, the OM-OFDM method is shown to offer significant performance gains when compared to CE-OFDM and traditional OFDM transmissions. In addition, the OM-OFDM method is able to accurately control the PAPR of a transmission for a targeted BER. By applying the power performance decision metric and complementary cumulative distribution function (CCDF), the proposed OM-OFDM method is shown to offer further performance gains when compared to existing PAPR methods, under frequency selective fading conditions. In this thesis, the OM-OFDM method has been combined with an existing active constellation extended (ACE) PAPR reduction method. To introduce a novel method called offset modulation with active constellation extension (OM-ACE), to control the PAPR of an OFDM signal. The theoretical BER expression for an OM-ACE transmission is presented and validated. Thereafter, by applying the decision metric and CCDF, the OM-ACE method is shown to offer performance improvements when compared to various PAPR methods. The use of OM-OFDM for cognitive radio applications is also investigated. Cognitive radio applications require transmissions that are easily detectable. The detection characteristics of an OM-OFDM and OFDM transmission are studied by using receiver operating characteristic curves. A derivation of a simplified theoretical closed-form expression, which relates the probability of a missed detection to the probability of a false alarm, for an unknown deterministic signal, at various signal-to-noise ratio (SNR) values is derived and validated. Previous expressions have been derived, which relate the probability of a missed detection to the probability of a false alarm. However, they have not been presented in such a generic closed-form expression that can be used for any unknown deterministic signal (for instance OFDM and OM-OFDM). Thereafter, an examination of the spectrum characteristics of an OM-OFDM transmission indicates its attractive detection characteristics. The proposed OM-OFDM method is further shown to operate at a significantly lower SNR value than an OFDM transmission, while still offering better detection characteristics than that of an OFDM transmission under Rician, Rayleigh and frequency selective fading channel conditions. In addition to its attractive PAPR properties, OM-OFDM also offers good detection characteristics for cognitive radio applications. These aspects make OM-OFDM a promising candidate for future deployment. / Thesis (PhD)--University of Pretoria, 2012. / Electrical, Electronic and Computer Engineering / unrestricted
16

Analysis of RISE's VIRC for Automotive EMC Immunity Testing

Lundberg, Andreas January 2021 (has links)
RCs (Reverberation Chambers) has historically been used mainly for aerospace and military purposes in EMC (Electromagnetic Compatibility) testing, but the interest also seems to increase in the automotive industry (the development of an international standard for vehicles is in progress). The vehicles of the future will most likely be electrified, wirelessly connected and autonomous, i.e., more control units, more communication systems, and more sensors, will be implemented in the vehicles requiring increased robustness against all possible electromagnetic interferences. EMC testing in an RC is a step in the direction of ensuring this robustness for the future vehicle platforms. Compared to a traditional EMC test method in a fully or semi-AC (Anechoic Chamber), testing in an RC has the advantage that the electromagnetic field will be isotropic, randomly polarized and homogeneous in a statistical sense, i.e., the exposed object will be surrounded by electromagnetic energy from all directions. It can be considered relatively expensive to build a brand new RC with motorized stirrers and associated measurement instrumentation, instead it would be desirable to perform immunity tests in a more cost-effective conductive fabric tent. The great advantage is the flexibility, the tent can be set up almost anywhere, even in already existing semi-ACs, such set-up is referred to as VIRC (Vibrating Intrinsic Reverberation Chamber). This thesis aims to develop a new test method in a VIRC environment. In order to achieve good RC conditions, the electromagnetic field must be statistically Rayleigh distributed. Furthermore, it is of great importance to avoid LoS (Line of Sight) between the antenna and the test object, and to achieve good stirring in the tent. Provided this can be achieved, there are still some challenges by testing in a tent. For example, the classical dwell time of two seconds for immunity testing in EMC is not possible to achieve in a VIRC environment. The validation in this thesis shows that the dwell time or the total exposure time in the tent might be enough to trigger possible malfunctions in today's modern high-speed communication vehicles. Furthermore, it is showed, testing in a VIRC gives good field uniformity and repeatability, and can trigger malfunctions that are not triggered in traditional EMC testing in semi-AC, i.e., ALSE (Absorber-Lined Shielded Enclosure) testing.
17

Approximation of Information Rates in Non-Coherent MISO wireless channels with finite input signals

Bothenna, Hasitha Imantha January 2017 (has links)
No description available.
18

Sledování spektra a optimalizace systémů s více nosnými pro kognitivní rádio / Spectrum sensing and multicarrier systems optimization for cognitive radio

Povalač, Karel January 2012 (has links)
The doctoral thesis deals with spectrum sensing and subsequent use of the frequency spectrum by multicarrier communication system, which parameters are set on the basis of the optimization technique. Adaptation settings can be made with respect to several requirements as well as state and occupancy of individual communication channels. The system, which is characterized above is often referred as cognitive radio. Equipments operating on cognitive radio principles will be widely used in the near future, because of frequency spectrum limitation. One of the main contributions of the work is the novel usage of the Kolmogorov – Smirnov statistical test as an alternative detection of primary user signal presence. The new fitness function for Particle Swarm Optimization (PSO) has been introduced and the Error Vector Magnitude (EVM) parameter has been used in the adaptive greedy algorithm and PSO optimization. The dissertation thesis also incorporates information about the reliability of the frequency spectrum sensing in the modified greedy algorithm. The proposed methods are verified by the simulations and the frequency domain energy detection is implemented on the development board with FPGA.
19

Efficient Traffic Management in Urban Environments

Zambrano Martínez, Jorge Luis 28 October 2019 (has links)
[ES] En la actualidad, uno de los principales desafíos a los que se enfrentan las grandes áreas metropolitanas es la congestión provocada por el tráfico, la cual se ha convertido en un problema importante al que se enfrentan las autoridades de cada ciudad. Para abordar este problema es necesario implementar una solución eficiente para controlar el tráfico que genere beneficios para los ciudadanos, como reducir los tiempos de viaje de los vehículos y, en consecuencia, el consumo de combustible, el ruido, y la contaminación ambiental. De hecho, al analizar adecuadamente la demanda de tráfico, es posible predecir las condiciones futuras del tráfico, y utilizar esa información para la optimización de las rutas tomadas por los vehículos. Este enfoque puede ser especialmente efectivo si se aplica en el contexto de los vehículos autónomos, que tienen un comportamiento más predecible, lo cual permite a los administradores de la ciudad mitigar los efectos de la congestión, como es la contaminación, al mejorar el flujo de tráfico de manera totalmente centralizada. La validación de este enfoque generalmente requiere el uso de simulaciones que deberían ser lo más realistas posible. Sin embargo, lograr altos grados de realismo puede ser complejo cuando los patrones de tráfico reales, definidos a través de una matriz de Origen/Destino (O-D) para los vehículos en una ciudad, son desconocidos, como ocurre la mayoría de las veces. Por lo tanto, la primera contribución de esta tesis es desarrollar una heurística iterativa para mejorar el modelado de la congestión de tráfico; a partir de las mediciones de bucle de inducción reales hechas por el Ayuntamiento de Valencia (España), pudimos generar una matriz O-D para la simulación de tráfico que se asemeja a la distribución de tráfico real. Si fuera posible caracterizar el estado del tráfico prediciendo las condiciones futuras del tráfico para optimizar la ruta de los vehículos automatizados, y si se pudieran tomar estas medidas para mitigar de manera preventiva los efectos de la congestión con sus problemas relacionados, se podría mejorar el flujo de tráfico en general. Por lo tanto, la segunda contribución de esta tesis es desarrollar una Ecuación de Predicción de Tráfico para caracterizar el comportamiento en las diferentes calles de la ciudad en términos de tiempo de viaje con respecto al volumen de tráfico, y aplicar una regresión logística a esos datos para predecir las condiciones futuras del tráfico. La tercera y última contribución de esta tesis apunta directamente al nuevo paradigma de gestión de tráfico previsto, tratándose de un servidor de rutas capaz de manejar todo el tráfico en una ciudad, y equilibrar los flujos de tráfico teniendo en cuenta las condiciones de congestión del tráfico presentes y futuras. Por lo tanto, realizamos un estudio de simulación con datos reales de congestión de tráfico en la ciudad de Valencia (España), para demostrar cómo se puede mejorar el flujo de tráfico en un día típico mediante la solución propuesta. Los resultados experimentales muestran que nuestra solución, combinada con una actualización frecuente de las condiciones del tráfico en el servidor de rutas, es capaz de lograr mejoras sustanciales en términos de velocidad promedio y tiempo de trayecto, ambos indicadores de un menor grado de congestión y de una mejor fluidez del tráfico. / [CA] En l'actualitat, un dels principals desafiaments als quals s'enfronten les grans àrees metropolitanes és la congestió provocada pel trànsit, que s'ha convertit en un problema important al qual s'enfronten les autoritats de cada ciutat. Per a abordar aquest problema és necessari implementar una solució eficient per a controlar el trànsit que genere beneficis per als ciutadans, com reduir els temps de viatge dels vehicles i, en conseqüència, el consum de combustible, el soroll, i la contaminació ambiental. De fet, en analitzar adequadament la demanda de trànsit, és possible predir les condicions futures del trànsit, i utilitzar aqueixa informació per a l'optimització de les rutes preses pels vehicles. Aquest enfocament pot ser especialment efectiu si s'aplica en el context dels vehicles autònoms, que tenen un comportament més predictible, i això permet als administradors de la ciutat mitigar els efectes de la congestió, com és la contaminació, en millorar el flux de trànsit de manera totalment centralitzada. La validació d'aquest enfocament generalment requereix l'ús de simulacions que haurien de ser el més realistes possible. No obstant això, aconseguir alts graus de realisme pot ser complex quan els patrons de trànsit reals, definits a través d'una matriu d'Origen/Destinació (O-D) per als vehicles en una ciutat, són desconeguts, com ocorre la majoria de les vegades. Per tant, la primera contribució d'aquesta tesi és desenvolupar una heurística iterativa per a millorar el modelatge de la congestió de trànsit; a partir dels mesuraments de bucle d'inducció reals fetes per l'Ajuntament de València (Espanya), vam poder generar una matriu O-D per a la simulació de trànsit que s'assembla a la distribució de trànsit real. Si fóra possible caracteritzar l'estat del trànsit predient les condicions futures del trànsit per a optimitzar la ruta dels vehicles automatitzats, i si es pogueren prendre aquestes mesures per a mitigar de manera preventiva els efectes de la congestió amb els seus problemes relacionats, es podria millorar el flux de trànsit en general. Per tant, la segona contribució d'aquesta tesi és desenvolupar una Equació de Predicció de Trànsit per a caracteritzar el comportament en els diferents carrers de la ciutat en termes de temps de viatge respecte al volum de trànsit, i aplicar una regressió logística a aqueixes dades per a predir les condicions futures del trànsit. La tercera i última contribució d'aquesta tesi apunta directament al nou paradigma de gestió de trànsit previst. Es tracta d'un servidor de rutes capaç de manejar tot el trànsit en una ciutat, i equilibrar els fluxos de trànsit tenint en compte les condicions de congestió del trànsit presents i futures. Per tant, realitzem un estudi de simulació amb dades reals de congestió de trànsit a la ciutat de València (Espanya), per a demostrar com es pot millorar el flux de trànsit en un dia típic mitjançant la solució proposada. Els resultats experimentals mostren que la nostra solució, combinada amb una actualització freqüent de les condicions del trànsit en el servidor de rutes, és capaç d'aconseguir millores substancials en termes de velocitat faig una mitjana i de temps de trajecte, tots dos indicadors d'un grau menor de congestió i d'una fluïdesa millor del trànsit. / [EN] Currently, one of the main challenges that large metropolitan areas have to face is traffic congestion, which has become an important problem faced by city authorities. To address this problem, it becomes necessary to implement an efficient solution to control traffic that generates benefits for citizens, such as reducing vehicle journey times and, consequently, use of fuel, noise and environmental pollution. In fact, by properly analyzing traffic demand, it becomes possible to predict future traffic conditions, and to use that information for the optimization of the routes taken by vehicles. Such an approach becomes especially effective if applied in the context of autonomous vehicles, which have a more predictable behavior, thus enabling city management entities to mitigate the effects of traffic congestion and pollution by improving the traffic flow in a city in a fully centralized manner. Validating this approach typically requires the use of simulations, which should be as realistic as possible. However, achieving high degrees of realism can be complex when the actual traffic patterns, defined through an Origin/Destination (O-D) matrix for the vehicles in a city, are unknown, as occurs most of the times. Thus, the first contribution of this thesis is to develop an iterative heuristic for improving traffic congestion modeling; starting from real induction loop measurements made available by the City Hall of Valencia, Spain, we were able to generate an O-D matrix for traffic simulation that resembles the real traffic distribution. If it were possible to characterize the state of traffic by predicting future traffic conditions for optimizing the route of automated vehicles, and if these measures could be taken to preventively mitigate the effects of congestion with its related problems, the overall traffic flow could be improved. Thereby, the second contribution of this thesis was to develop a Traffic Prediction Equation to characterize the different streets of a city in terms of travel time with respect to the vehicle load, and applying logistic regression to those data to predict future traffic conditions. The third and last contribution of this thesis towards our envisioned traffic management paradigm was a route server capable of handling all the traffic in a city, and balancing traffic flows by accounting for present and future traffic congestion conditions. Thus, we perform a simulation study using real data of traffic congestion in the city of Valencia, Spain, to demonstrate how the traffic flow in a typical day can be improved using our proposed solution. Experimental results show that our proposed solution, combined with frequent updating of traffic conditions on the route server, is able to achieve substantial improvements in terms of average travel speeds and travel times, both indicators of lower degrees of congestion and improved traffic fluidity. / Finally, I want to thank the Ecuatorian Republic through the "Secretaría de Educación Superior, Ciencia, Tecnología e Innovación" (SENESCYT), for granting me the scholarship to finance my studies. / Zambrano Martínez, JL. (2019). Efficient Traffic Management in Urban Environments [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/129865 / TESIS
20

Evaluation of Thoracic Injury Risk of Heavy Goods Vehicle Occupants during Steering Wheel Rim Impacts to Different Rib Levels / Undersökning av risk för thoraxskador hos lastbilsförare vid rattislag mot olika revbensnivåer

Xu, Jia Cheng January 2019 (has links)
The interior of heavy goods vehicles (HGVs) differs from passenger cars. Both the steering wheel and the occupant are positioned differently in a HGV and increases the risk of steering wheel rim impacts. Such impact scenarios are relatively unexplored compared to passenger car safety studies that are more prevalent within the field of injury biomechanics. The idea with using human body models (HBMs) is to complement current crash test dummies with biomechanical data. Furthermore, the biofidelity of a crash dummy for loading similar to a steering wheel rimimpact is relatively unstudied and especially to different rib levels. Therefore, the aim with this thesis was to evaluate HGV occupant thoracic response between THUMS v4.0 and Hybrid III (H3) during steering wheel rim impacts with respect to different rib levels (level 1-2, 3-4, 6-7, 7-8, 9-10) with regards to ribs, aorta, liver, and spleen. To the author’s best knowledge, use of local injury risk functions for thoracic injuries is fairly rare compared to the predominant usage of global injury criteria that mainly predicts the most commonthoracic injury risk, i.e. rib fractures. Therefore, local injury criteria using experimental test datahave been developed for the ribs and the organs. The measured parameters were chest deflectionand steering wheel to thorax contact force on a global level, whilst 1st principal Green-Lagrangestrains was assessed for the rib and the organ injury risk. The material models for the liver and the spleen were remodelled using an Ogden material model based on experimental stress-strain data to account for hyperelasticity. Rate-dependency was included by iteration of viscoelastic parameters. The contact modelling of the organs was changed from a sliding contact to a tied contact to minimize unrealistic contact separations during impact. The results support previous findings that H3 needs additional instrumentation to accurately register chest deflection for rib levels beyond its current range, namely at ribs 1-2, 7-8, and 9-10. For THUMS, the chest deflection were within reasonable values for the applied velocities, but there were no definite injury risk. Fact is, the global injury criteria might overpredict the AIS3 injury risk (rib fractures) for rib level 1-2, 7-8, and 9-10. The rib strains could not be correlated with the measured chest deflections. This was explained by the unique localized loading characterized by pure steering wheel rim impact that mainly affected the sternum and the rib cartilage while minimizing rib deformation. The organ strains indicate some risk of rupture where the spleen deforms the most at rib levels 3-4 and 6-7, and the liver and the aorta at rib levels 6-7 and 7-8. This study provides a framework for complementing H3 with THUMS for HGV occupant safety with emphasis on the importance of using local injury criteria for functional injury prediction, i.e. prediction of injury risk using parameters directly related to rib fracture or organ rupture. Local injury criteria are thus a powerful safety assessment tool as it is independent on exterior loading such as airbag, steering wheel hub, or seat belt loading. It was noticed that global injury criteria with very localized impacts such as rim impacts have not been studied and will affect rib fracture risk differently than what has been studied using airbag or seat belt restraints. However, improvements are needed to accurately predict thoracic injury risk at a material level by finding more data for the local injury risk functions. Conclusively, it is clear that Hybrid III has insufficient instrumentation and is in need of upgrades to register chest deflections at multiple rib levels. Furthermore, the following are needed: better understanding of global injury criteria specific for HGV occupant safety evaluation, more data for age-dependent (ribs) and rate-dependent (organs) injury risk functions, a tiebreak contact with tangential sliding for better organ kinematics during impacts, and improving the biofidelity of the material models using data from tissue level experiments. / Förarmiljön i lastbilar gentemot personbilar är annorlunda, i detta kontext med avseende på främst ratt- och förarposition som ökar risken för islag med rattkransen för lastbilsförare. Sådana islag är relativt outforskat jämfört med passiv säkerhet för personbilar inom skadebiomekaniken. Tanken bakom användning av humanmodeller är att komplettera nuvarande krockdockor med biomekanisk information. Dessutom är biofideliteten hos en krockdocka vid rattislag relativt okänt, speciellt vid olika revbensnivåer. Därför är målet med detta examensarbete att undersöka thoraxresponsen hos en lastbilsförare genom att använda THUMS v4.0 och Hybrid III (H3) under rattislag med avseende på revbensnivåer (nivå 1-2, 3-4, 6-7, 7-8, och 9-10) och revben, aorta, lever, och mjälte. Enligt författaren verkar användning av lokala riskfunktioner för thoraxskador relativt ostuderat jämfört med den övervägande användningen av globala riskfunktioner som huvudsakligen förutser den mest vanligt förekommande thoraxskadan, nämligen revbensfrakturer. Därför har lokala riskfunktioner skapats för revben och organ, baserat på experimentell data. Uppmätta parametrar var bröstinträngning och kontaktkraft mellan ratt och thorax på global nivå, medan första Green-Lagrange huvudtöjningen användes för att evaluera skaderisken för revben och organ. Materialmodeller för lever och mjälte ommodellerades baserat på experimentell spänning-töjningsdata med Ogdens materialmodell för att ta hänsyn till hyperelasticitet. Töjningshastighetsberoendet inkluderades genom att iterera fram viskoelastiska parametrar. Kontaktmodellering av organ gjordes genom att ändra från glidande kontakt till en låsande kontakt för att minimera orealistisk kontaktseparation under islagsfallen. Resultaten stödjer tidigare studier där H3 visat sig behöva ytterligare givare för att noggrannt kunna registrera bröstinträngning vid olika revbensnivåer bortom dess nuvarande räckvidd, nämligen vid revben 1-2, 7-8, och 9-10. Uppmätt bröstinträngning i THUMS var rimliga för hastighetsfallen men gav inte någon definitiv risk för skada. Faktum är att de globala riskfunktionerna kan överskatta AIS3 risken vid revben 1-2, 7-8, och 9-10. Revbenstöjningarna kunde inte korreleras med bröstinträngningarna. Detta kunde förklaras genom de unika lastfallen som karakteriseras av rena rattislag som främst påverkar sternum och revbensbrosk som i sin tur minimerar deformation av revben. Organtöjningarna indikerar på någon risk för ruptur där mjälten deformerar som mest vid revben 3-4 och 6-7, medan för både levern och aortan sker det vid revben 6-7 och 7-8. Denna studie presenterar ett sätt att komplettera H3 med THUMS inom passiv säkerhet för lastbilsförare med fokus på lokala riskfunktioner för funktionell skadeprediktering dvs. prediktering av skaderisken med hjälp av parametrar som är direkt relaterat till revbensfraktur eller organruptur. Lokala riskfunktioner utgör en kraftfull säkerhetsbedömning som är oberoende av externa lastfall som t.ex. airbag, rattcentrum, eller bälteslast. I denna studie noterades det att de globala riskkriterierna inte har undersökts med väldigt lokala islag som rattislagen utgör och kommer därför att påverka risken för revbensfraktur annorlunda gentemot vad som har studerat, t.ex. airbag eller bältelast. Däremot behövs det mer data för de lokala riskkriterierna för att kunna prediktera thoraxskaderisken med ökad noggrannhet. Avslutningsvis, det är tydligt att Hybrid III har otillräckligt med givare och behöver förbättras för att kunna registrera bröstinträngning vid flera revbensnivåer. Vidare behövs följande: bättre förståelse för globala riskfunktioner anpassat inom passiv säkerhet för lastbilsförare, mer data för åldersberoende (revben) och töjningshastighetsberoende (organ) riskfunktioner, en ”tiebreak” kontakt med tangientiell glidning för bättre organkinematik, och ökad biofidelitet av materialmodeller genom att använda data från vävnadsexperiment.

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