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Background Whole-body skeletal radiography has traditionally been used in the management of multiple myeloma for defining treatment strategies. For several reasons, radiography has been replaced by computed tomography (CT) covering the same regions. Purpose To evaluate the body mass index (BMI) adjusted effective radiation dose from two different methods of whole-body radiologic imaging for multiple myeloma assessment. Material and Methods The current investigation analyses the dose to patients resulting from the two methods, conventional radiography supplemented with tomosynthesis (203 examinations) and CT (264 examinations). All patients subject to myeloma staging for 4.5 years were included in the study. Exposure parameters were collected from the PACS and conversion factors were calculated using the software packages PCXMC and VirtualDose enabling the calculation of the effective dose to each patient based on BMI. The Mann–Whitney U test was used for comparisons between groups. Results Patients were subject to a median effective dose of 2.5 mSv for conventional radiography and 5.1 mSv for CT, a statistically significant difference. Conclusion The effective dose for whole-body CT in assessing multiple myeloma is twice as high as for whole-body skeletal survey with modern digital radiography, but at a low level and considerably less than the levels quoted in the earlier studies of ∼30 mSv when the technique was first explored.

Advances in Vehicular Cyber-Physical Systems (VCPS) are the primary enablers of the shift from no automation to fully autonomous vehicles (AVs). One of the impacts of this shift is to develop safe AVs in which most or all of the functions of the human driver are replaced with an intelligent system. However, while some progress has been made in equipping AVs with advanced AI capabilities, VCPS designers are still faced with the challenge of designing trustworthy AVs that are in sync with the unpredictable behaviours of humans. In order to address this challenge, we present a model that describes how a Human Ambassador component can be integrated into the overall design of a new generation of VCPS. A scenario is presented to demonstrate how the model can work in practice. Formalisation and co-simulation challenges associated with integrating the Human Ambassador component and future work we are undertaking are also discussed.

Driver intention recognition is essential to the development of advanced driver assistance systems providing real-time support. Current approaches for the recognition of overtaking intentions focus on drivers’ observable behaviors, neglecting the fact that the intention to overtake a slower lead car emerges earlier than the resulting behavior. This paper aims to distinguish the "intention emerging process", when drivers form the initial intention to overtake, from the "action executing process", when drivers execute the overtaking maneuver. A driving simulator study has been conducted to investigate the influence of the lead vehicle type and lead vehicle speed on initiating driver’ intention on overtaking on rural roads, and the effect of the complexity of the oncoming traffic on executing overtaking. The results show that the initial driver intention to overtake appears much earlier than the execution of the overtaking maneuver. The lead vehicle speed has a significant influence on initial driver intention in the "intention emerging process", while time to overtake increases with the number of the oncoming vehicles in the "action execution process". These results can contribute to the development of models for driver intention recognition by extending the prediction horizon from the recognition to a prediction of driving maneuvers.

Background Recently, total hip arthroplasty (THA) has come to focus on restoration of individual anatomy including femoral neck anteversion and global offset (femoral and acetabular offset). Three-dimensional (3D) computed tomography (CT) data could provide a better basis for preoperative templating. The use of CT has been hampered by high radiation dose. Purpose To evaluate the effective dose used in pelvis and hip CT for THA templating. Material and Methods CT data from two clinical trials of THA were evaluated for CT scan length and volume CT dose index (CTDIvol). The effective doses from hip-knee-ankle CT and pelvis and hip radiography were compared. Conversion factors for effective dose for radiography were calculated using the PCXMC software. Results A reduced dose CT protocol for pelvis imaging gave a substantial dose reduction compared with standard CT, while maintaining sufficient image quality. Between the two clinical trials there was a significant reduction in effective CT dose corresponding to changes in the CT protocol ( P Conclusion Although the CT dose remained higher than for radiography, potential reductions in scan length could reduce the dose further so that CT would have a comparable level of risk to radiography with the added benefit of 3D templating.

Adapting the driving style of autonomous vehicles to fit the user's preferences may reduce uncomfortable user experiences. This can support the adoption process of the technology. We present ongoing research about adaptive customizable user profiles for autonomous driving styles. We propose a system that allows users to customize maneuver-based driving styles via a graphical user interface. Additionally, the system can learn user preferences based on user state assessment. We plan to design and evaluate this system with two driving simulator studies.

We performed a driving simulator study to investigate merging decisions with respect to an interaction partner in time-critical situations. The experimental paradigm was a two-alternative forced choice, where the subjects could choose to merge before human vehicles or highly automated vehicles (HAV). Under time pressure, subjects showed a significantly higher gap acceptance during merging situations when interacting with HAV. This confirmed our original hypothesis that when interacting with HAV, drivers would exploit the HAV's technological advantages and defensive programming in time-critical situations.

Highly automated vehicles, occasionally require users to resume vehicle control from non-driving related tasks by issuing cues called take-over request (TOR). Due to being engaged in non-driving related tasks (NDRT), users have a decreased level of situational awareness of the driving context. Therefore, user interface designs for TORs should ensure smooth transitions from the NDRTs to vehicle control. In this paper, we investigated the role of decision priming cues as TORs across different levels of NDRT engagement. In a driving simulator, users performed a reading span task while driving in automated mode. They received audio-visual TORs which primed them with an appropriate maneuver (steering vs. braking), depending on the traffic situation. Our results showed that priming users with upcoming maneuvers results in faster responses and longer time to collision to obstacles. However, the level of engagement in NDRT does not affect user responses to TORs.

Thoracic spine radiography becomes more difficult with age. Tomosynthesis is a low-dose tomographic extension of radiography which may facilitate thoracic spine evaluation. This study assessed the added value of tomosynthesis in imaging of the thoracic spine in the elderly. Four observers compared the image quality of 50 consecutive thoracic spine radiography and tomosynthesis data sets from 48 patients (median age 67 years, range 55–92 years) on a number of image quality criteria. Observer variation was determined by free-marginal multirater kappa. The conversion factor and effective dose were determined from the dose–area product values. For all observers significantly more vertebrae were seen with tomosynthesis than with radiography (mean 12.4/9.3, P

Purpose CT-scanning for treatment planning in radiotherapy is often hampered by the fact that scan parameter optimization may be limited due to treatment planning system constraints. The current work reviews the exposure levels for a selected group of treatment locations, i.e. head, head&neck, thorax, breast, abdomen and prostate. Methods Equal scan protocols, based on filtered back projection, are set on the two scanners (Siemens Definition AS+). Scan parameters from the CT scanners are automatically transferred, using the DICOM SR protocol, after each scanning sequence to a dose monitoring system (Sectra DoseTrack). These data include, but are not limited to CTDI, DLP, weight and age. For adult patients with weights between 60 and 80 kg the median CTDI (mGy) and DLP (mGycm) values as well as standard deviation (1 SD) have been calculated for the treatment locations. 20 or more patients are included for each location. Results The exposure levels for the selected sites are more or less equal between the two scanners. CTDI and DLP values (CTDI/DLP) for CT 1 are: Head 41 ± 4/1125 ± 145, Head&neck 11 ± 1/452 ± 61, Thorax 9 ± 3/390 ± 161, Breast ca 9 ± 2/355 ± 61, Abdomen 17 ± 3/815 ± 239, Prostate ca respectively. Corresponding values for CT 2 are: Head 42 ± 6/1168 ± 222, Head&neck 11 ± 1/458 ± 89, Thorax 9 ± 2/412 ± 136, Breast ca 9 ± 1/357 ± 60, Abdomen 17 ± 3/801 ± 177, Prostate ca 17 ± 2/813 ± 110 for each scan site. CTDI values are well below current national dose reference levels (DRL) in diagnostic radiology were these are given. DLP values are however slightly outside the diagnostic DRL values were these exist. Increased scan length requirements due to treatment planning flexibility, dose calculation accuracy and DVH evaluation of complete organs add to higher DLP values. Conclusions Exposure levels have been evaluated for the head, head&neck, thorax, breast, abdomen and prostate regions. These exposure levels turn out to be lower for CTDI than current national diagnostic radiology dose reference levels indicating well adapted scan protocols. Scan length requirements for treatment planning do however add to DLP making them slightly higher than current DRL levels.

Tomosynthesis (digital tomography) is a recently introduced low-dose alternative to CT in the evaluation of the lungs in patients with cystic fibrosis and pulmonary nodules. Previous studies have reported an adult effective dose of 0.12-0.13 mSv for chest tomosynthesis. The aim of this study was to determine the paediatric effective dose from the dose-area-product. During a 3-y period, 38 children with cystic fibrosis and 36 paediatric oncology patients were examined with chest tomosynthesis, totally 169 posteroanterior and 17 anteroposterior examinations (40 boys and 34 girls, mean age 13.7 y, range 7-20 y). Using recently reported paediatric chest tomosynthesis conversion factors (0.23-1.09 mSv Gy cm(-2)) corrected for sex, age and energy, the mean posteroanterior effective dose calculated was 0.17 mSv; using the proposed simplified conversion factors of 0.6 (8-10 y), 0.4 (11-14 y) and 0.3 mSv Gy cm(-2) (15-19 y), the mean posteroanterior effective dose calculated was 0.15 mSv. As the difference in the calculated effective dose was minor, it is recommendable to use the simplified conversion factors. Using the conversion factor for adult chest tomosynthesis (0.26 mSv Gy cm(-2)), the mean effective dose was 0.11 mSv. Anteroposterior exposures had considerably higher effective dose. By using conversion factors adapted for children, the calculated risks from radiologic procedures will be more accurate.

The capacitive and faradaic responses of well-aligned MWCNT array electrodes were determined by cyclic voltammetry and impedance spectroscopy. The impedance responses of the array electrodes were modeled by transition line models.

Capacitive and electron transfer (faradaic) characteristics of well‐aligned multi‐walled carbon nanotube (MWCNT) array electrodes as determined by cyclic voltammetry and impedance spectroscopy were reported. The characteristics were discussed in dependence on the specific deposit mass of the MWCNT arrays, which linearly increased with the deposit thickness of the arrays.

The synthesis, isolation, characterization, functionalization and application of furan‐like bridged dimeric fullerene oxides are reported. A synthesis of C130O in yields of 20% is presented. A preparation of highly pure, soluble mono‐, bis‐ and tris‐adducts of a diazoalkane addition reaction and a Bingel cyclopropanation reaction on C120O in preparative amounts using conventional laboratory methods is reported. A synthesis of regio‐controlled mono‐ and bis‐functionalized C120O, C130O and C140O derivatives in yields of more than 10% is presented. C120O, C130O, C140O and the mono‐adducts of the diazoalkane addition reaction and the Bingel reaction on C120O are characterized by thermogravimetric analyses, ultraviolet‐visible‐spectroscopy and cyclic voltammetry. The application of the mono‐adduct of the diazoalkane addition reaction on C120O as electron acceptor in a bulk‐heterojunction solar cell is reported.

Highly pure, isomerically mixed dimeric C70 fullerene oxide C140O was prepared in preparative amounts using conventional laboratory methods. Unknown trimeric C70 fullerene oxides C210On (n = 2, 3) were by‐products of the preparation. The prepared isomeric C140O mixture was characterized by high pressure liquid chromatography (HPLC), mass‐ (MS‐), infra‐red‐ (IR‐), and ultraviolet‐visible‐ (UV‐vis‐) spectroscopies, as well as by cyclic voltammetry (CV) and thermo‐gravimetric analyses (TGA).

To evaluate the dose values predicted by several calculation algorithms in two treatment planning systems, Monte Carlo (MC) simulations and measurements by means of various detectors were performed in heterogeneous layer phantoms with water- and bone-equivalent materials. Percentage depth doses (PDDs) were measured with thermoluminescent dosimeters (TLDs), metal-oxide semiconductor field-effect transistors (MOSFETs), plane parallel and cylindrical ionization chambers, and beam profiles with films. The MC code used for the simulations was the PENELOPE code. Three different field sizes (10 x 10, 5 x 5, and 2 x 2 cm2) were studied in two phantom configurations and a bone equivalent material. These two phantom configurations contained heterogeneities of 5 and 2 cm of bone, respectively. We analyzed the performance of four correction-based algorithms and one based on convolution superposition. The correction-based algorithms were the Batho, the Modified Batho, the Equivalent TAR implemented in the Cadplan (Varian) treatment planning system (TPS), and the Helax-TMS Pencil Beam from the Helax-TMS (Nucletron) TPS. The convolution-superposition algorithm was the Collapsed Cone implemented in the Helax-TMS. All the correction-based calculation algorithms underestimated the dose inside the bone-equivalent material for 18 MV compared to MC simulations. The maximum underestimation, in terms of root-mean-square (RMS), was about 15% for the Helax-TMS Pencil Beam (Helax-TMS PB) for a 2 x 2 cm2 field inside the bone-equivalent material. In contrast, the Collapsed Cone algorithm yielded values around 3%. A more complex behavior was found for 6 MV where the Collapsed Cone performed less well, overestimating the dose inside the heterogeneity in 3%-5%. The rebuildup in the interface bone-water and the penumbra shrinking in high-density media were not predicted by any of the calculation algorithms except the Collapsed Cone, and only the MC simulations matched the experimental values within the estimated uncertainties. The TLD and MOSFET detectors were suitable for dose measurement inside bone-equivalent materials, while parallel ionization chambers, applying the same calibration and correction factors as in water, systematically underestimated dose by 3%-5%.

Functional near-infrared spectroscopy (fNIRS) is a versatile imagining modality whose popularity is increasing exponentially in the neuroimaging society. Our research attempts to quantify workload in a natural driving scenario with multiple parallel tasks using fNIRS. Nine young adults participated in this study where they drove in a driving simulator for a period of 100 minutes while we continuously recorded fNIRS data. We used an n-back task to induce different workload levels forcing the participants to remember the previous one, two, three or four speed signs and adjust their speed accordingly while they interact with traffic in the virtual reality driving simulator scenario. Our results indicate that measuring the hemodynamic responses from the bilateral prefrontal cortex (PFC) can be used reliably to quantify cognitive workload levels even in more complex naturalistic tasks.

The identification of sounds is an important tool in ubiquitous and context aware applications. Today's smartphones are capable of performing even computational intensive tasks, like digital signal processing and pattern recognition. In this contribution an implementation scheme and a framework for sound recognition for smartphones are presented. A basic sound recognition flow consists of preprocessing, feature extraction, feature selection, classiication, and action trigger. A flow is not hard coded but described in a JSON file and build dynamically by the framework. The framework itself is implemented in Java for the Android operating system. But specific algorithms can be realized in Java, C(++), and Renderscript for execution on the CPU, or in Filterscript for execution on a GPU. An example flow is presented and benchmark results are shown for Java-, C-, and Filterscript-implementations of Mel Frequency Cepstral Coefficients (MFCC). Recommendations for technology selection are made.

Dose calculations for treatment planning of photon beam radiotherapy require a model of the beam to drive the dose calculation models. The beam shaping process involves scattering and filtering that yield radiation components which vary with collimator settings. The necessity to model these components has motivated the development of multisource beam models. We describe and evaluate clinical photon beam modeling based on multisource models, including lateral beam quality variations. The evaluation is based on user data for a pencil kernel algorithm and a point kernel algorithm (collapsed cone) used in the clinical treatment planning systems Helax-TMS and Nucletron-Oncentra. The pencil kernel implementations treat the beam spectrum as lateral invariant while the collapsed cone involves off axis softening of the spectrum. Both algorithms include modeling of head scatter components. The parameters of the beam model are derived from measured beam data in a semiautomatic process called RDH (radiation data handling) that, in sequential steps, minimizes the deviations in calculated dose versus the measured data. The RDH procedure is reviewed and the results of processing data from a large number of treatment units are analyzed for the two dose calculation algorithms. The results for both algorithms are similar, with slightly better results for the collapsed cone implementations. For open beams, 87% of the machines have maximum errors less than 2.5%. For wedged beams the errors were found to increase with increasing wedge angle. Internal, motorized wedges did yield slightly larger errors than external wedges. These results reflect the increased complexity, both experimentally and computationally, when wedges are used compared to open beams.

An extensive set of benchmark measurement of PDDs and beam profiles was performed in a heterogeneous layer phantom, including a lung equivalent heterogeneity, by means of several detectors and compared against the predicted dose values by different calculation algorithms in two treatment planning systems. PDDs were measured with TLDs, plane parallel and cylindrical ionization chambers and beam profiles with films. Additionally, Monte Carlo simulations by means of the PENELOPE code were performed. Four different field sizes (10 x 10, 5 x 5, 2 x 2, and 1 x 1 cm2) and two lung equivalent materials (CIRS, p(w)e=0.195 and St. Bartholomew Hospital, London, p(w)e=0.244-0.322) were studied. The performance of four correction-based algorithms and one based on convolution-superposition was analyzed. The correction-based algorithms were the Batho, the Modified Batho, and the Equivalent TAR implemented in the Cadplan (Varian) treatment planning system and the TMS Pencil Beam from the Helax-TMS (Nucletron) treatment planning system. The convolution-superposition algorithm was the Collapsed Cone implemented in the Helax-TMS. The only studied calculation methods that correlated successfully with the measured values with a 2% average inside all media were the Collapsed Cone and the Monte Carlo simulation. The biggest difference between the predicted and the delivered dose in the beam axis was found for the EqTAR algorithm inside the CIRS lung equivalent material in a 2 x 2 cm2 18 MV x-ray beam. In these conditions, average and maximum difference against the TLD measurements were 32% and 39%, respectively. In the water equivalent part of the phantom every algorithm correctly predicted the dose (within 2%) everywhere except very close to the interfaces where differences up to 24% were found for 2 x 2 cm2 18 MV photon beams. Consistent values were found between the reference detector (ionization chamber in water and TLD in lung) and Monte Carlo simulations, yielding minimal differences (0.4%+/-1.2%). The penumbra broadening effect in low density media was not predicted by any of the correction-based algorithms, and the only one that matched the experimental values and the Monte Carlo simulations within the estimated uncertainties was the Collapsed Cone Algorithm.

Dose calculations with a collapsed cone algorithm implemented in a clinical treatment planning system have been studied. The algorithm has been evaluated in homogeneous as well as in heterogeneous media, and the results have been compared to measurements and Monte Carlo simulations. Commonly encountered clinical beam configurations as well as more complex geometries have been pursued to test the limitations of the model. The results show that the accuracy level reached allows for clinical use. Some situations, e.g., large wedge beams and dose calculations in the build up region, not specific to the collapsed cone model, show deviations (outside ±3%) compared to measurements. PACS number(s): 87.53.Bn, 87.53.–j, 87.66.–a

The approach in treatment planning of applying beam quality correction factors to model compensator-induced depth-hardening effects is investigated and the present work comprises a dosimetric verification of the model for a common compensator material. Lead sheet modulators for four different phantom shapes were designed using a treatment planning system based on the model. The modulators were designed to yield homogeneous dose in a plane. The calculated modulation created by the lead sheets was re-imported into the treatment planning system and applied to a water phantom geometry for verification purposes. Comparing measurements, a total of 31 different geometries were measured, with calculations in this geometry showing good agreement for depth doses, dose profiles and output data with a maximum deviation of 4% except locally in the penumbra region and close to the edges of the cut lead sheets.

This paper presents the results of a first step in a longer - term research approach to investigate the influence of uncertainty on drivers' trust in Advanced Driver Assistance Systems (ADAS). The first step is to classify driver's uncertainty in lane changing situations. In a pilot study(n=5), the effect of distance gap on driver's uncertainty was studied using a driving simulator. The results indicated a U shaped relationship between distance gaps, reaction times and uncertainty scores.

Modern driver assistance systems make increasing use of auditory and tactile signals in order to reduce the driver's visual information load. This entails potential crossmodal interaction effects that need to be taken into account in designing an optimal system. Here we show that saccadic reaction times to visual targets (cockpit or outside mirror), presented in a driving simulator environment and accompanied by auditory or tactile accessories, follow some well-known spatiotemporal rules of multisensory integration, usually found under confined laboratory conditions. Auditory nontargets speed up reaction time by about 80 ms. The effect tends to be maximal when the nontarget is presented 50 ms before the target and when target and nontarget are spatially coincident. The effect of a tactile nontarget (vibrating steering wheel) was less pronounced and not spatially specific. It is shown that the average reaction times are well-described by the stochastic “time window of integration” model for multisensory integration developed by the authors. This two-stage model postulates that crossmodal interaction occurs only if the peripheral processes from the different sensory modalities terminate within a fixed temporal interval, and that the amount of crossmodal interaction manifests itself in an increase or decrease of second stage processing time. A qualitative test is consistent with the model prediction that the probability of interaction, but not the amount of crossmodal interaction, depends on target–nontarget onset asynchrony. A quantitative model fit yields estimates of individual participants' parameters, including the size of the time window. Some consequences for the design of driver assistance systems are discussed.

The suitability of high-Z materials as build-up caps for head-scatter measurements has been investigated. Build-up caps are often used to enable characterization of fields too small for a mini-phantom. We have studied lead and brass build-up caps with sufficiently large wall thicknesses, as compared to the range of contaminating electrons originating in the accelerator head, and compared them with build-up caps made of ionization chamber equivalent materials, i.e. graphite. The results were also compared with measurements taken using square and cylindrical polystyrene mini-phantoms. Field sizes ranging from 3 cm x 3 cm up to 40 cm x 40 cm were studied for nominal photon energies of 4, 6, 10 and 18 MV. The results show that the use of lead and brass build-up caps produces normalized head-scatter data slightly different from graphite build-up caps for large fields at high photon energies. At lower energies, however, no significant differences were found. The intercomparison between the two different plastic mini-phantoms and graphite caps showed no differences.

A common limitation in treatment planning systems for photon dose calculation is to ignore the impact on electron transport and photon scatter from patient heterogeneities. The heterogeneity correlation is often based on scaling operations along beam rays as for the method according to Batho or the more novel approach of 1D convolutions along beam paths applied in pencil-beam-based systems. The effects of the limitation have been studied in a mediastinum geometry for a wide range of beam qualities by comparing the results from a pencil-beam-based treatment planning system with the results from Monte Carlo calculations. As expected, the deviations within unit-density volumes are small while deviations in low-density volumes increase with increasing beam energy from approximately 3% for 4 MV to 14% for 18 MV x-rays as a result of increased electron disequilibrium.

This paper presents the results of a Hierarchical Task Analysis (HTA) that show how drivers represent the driving task of merging onto the freeway. These individual representations were examined to precise and improve a cognitive driver model which simulates freeway merging manoeuvres in a real-time driving simulator. It could be demonstrated that the goal hierarchy of the drivers corresponds to the goal hierarchy of the driver model in several critical aspects regarding the contents of the goals. However, both hierarchies differed regarding the process in which some goals are achieved. Probably a consideration of the processes that are part of the drivers’ goal hierarchy will improve the validity of the driver model.

Background We explore a model-based approach for the design of advanced driver assistance systems (ADAS) where a computational cognitive driver model based on psychological theories of driver behaviour interacts in a simulated environment with the simulated ADAS to predict the positive and possible negative effects of the ADAS on driver behaviour early in the ADAS development process. Applying such an approach to the design of ADAS requires the availability of a valid driver model that can be used to assess the effect of system proto types on human driving behaviour in simulations.

This chapter provides a detailed description of the current neoclassical growth theories. Beginning with a short introduction on exponential growth patterns, the following sections present three different model types: Exogenous, Endogenous and Semi-endogenous growth. The individual sub-chapters conclude with an analysis of demographic components within the model.

This chapter consists of two major parts. In the first subchapter, the semi-endogenous demographic growth model is explained in detail. The model consists of four sectors – population, R&D, growth and utility. The paper is structured in this order, as the origin of growth is the population sector which influences the R&D sector and the growth sector. The utility sector adds to the growth sector and serves as indicator for the evaluation of policies. This subchapter concludes after the model is initialized and executable.

In this chapter the author’s semi-endogenous growth model is applied to various demographic problems. The presented scenarios are conceptual. Thus, general results and explanations for the case of aging and shrinking of economies are presented. In later empirical work one can estimate all exogenous variables for a full parameter adoption. Then the model delivers results – based on the neoclassical growth theory – on how a country will develop over time.