Automotive safety and machine learning: Initial results from a study on how to adapt the ISO 26262 safety standard

Machine learning (ML) applications generate a continuous stream of success stories from various domains. ML enables many novel applications, also in safety-critical contexts. However, the functional safety standards such as ISO 26262 did not evolve to cover ML. We conduct an exploratory study on which parts of ISO 26262 represent the most critical gaps between safety engineering and ML development. While this paper only reports the first steps toward a larger research endeavor, we report three adaptations that are critically needed to allow ISO 26262 compliant engineering, and related suggestions on how to evolve the standard

Incentive pay-systems and its impact on motivation and goal congruence : a case study at Tele2 in Kista, Stockholm

Företagens prestation styrs i hög grad av medarbetarnas prestation vilket innebär att motiverade och tillfredsställda medarbetare är grunden för ett välmående företag. Belöningssystem är ett verktyg företag kan använda sig av då de vill motivera sina medarbetare till att arbeta mot önskad målsättning. Tidigare studier inom området visar däremot att det finns delade meningar angående hur resultatbaserade belöningssystem påverkar motivationen hos medarbetare. Organisationens målsättning kan stå i konflikt med medarbetarnas individuella målsättningar om dessa mål inte överensstämmer med varandra. En konsekvens av att det uppstår konflikter mellan organisationens mål och medarbetarnas individuella målsättningar är att det kan leda till en lägre grad av målkongruens vilket då innebär att medarbetare och organisation arbetar i olika riktningar. Tidigare studier har fokuserat på belöningssystem och motivation, men det finns relativt få undersökningar som kopplar dessa teorier till målkongruens. Syftet med denna uppsats är att öka förståelsen för vilka effekter ett belöningssystem har på medarbetarnas och organisationens målkongruens. Studien baseras på en kvalitativ fallstudie med induktiv ansats. Studien är avgränsad till att undersöka Tele2:s business to business-enhet i Kista, Stockholm. Den specifika avgränsningen gör att resultaten som visas i studien inte kan anses generaliserbara. Empiri för undersökningen har inhämtats från sex semistrukturerade intervjuer med chefer och medarbetare hos fallföretaget Tele2:s business to business-enhet i Kista, Stockholm. Urvalet var av icke-slumpmässig karaktär. Respondentgruppen bestod av både chefer och medarbetare för att få fler perspektiv på hur belöningssystem, motivation och målkongruens kan länkas samman. Det teoretiska kapitlet är utformat med fyra ämnesområden där relevanta teorier presenterats inom respektive område. Det teoretiska ramverk som användes för studien baseras på teorier kring belöningssystem, motivation och målkongruens. Efter att ha analyserat den insamlade empirin har författarna kommit fram till att belöningssystemet inte bidrar till att öka eller sänka graden av motivation på sikt, utan endast upprätthåller den nuvarande motivationsnivån. Det innebär att det aktuella belöningssystemet varken höjer eller sänker graden av motivation. I takt med att medarbetarna tar ett steg upp på karriärsstegen minskar betydelsen av det provisionsbaserade belöningssystemet. Faktorer som personlig utveckling och ansvar blir efterhand mer centrala faktorer än monetära belöningar i sin betydelse för motivationen. Genom att belöna prestationer som bidrar till organisationens övergripande mål, skapas målöverensstämmelse mellan medarbetare och organisation. Detta innebär i praktiken att medarbetarna måste arbeta mot företagets målsättningar för att ha möjlighet att nå sina individuella mål.Drawing from previous research on incentive-pay systems, motivation and goal congruence, this study focuses on the relationship between these subjects in order to find a link between motivation and incentive-pay systems and its effect on goal congruence. The study is based on a qualitative case study with an inductive approach. Empirical data were collected from six semi-structured interviews at Tele2 business to business-unit in Kista, Stockholm. The specific delimitation makes the results shown in this study non generalizable. The theoretical framework used for this study is based on theories of incentive pay-systems, motivation and goal congruence. The result of this study show that incentive pay-system does not increase nor decrease the level of motivation in a long term perspective, but simply helps to maintain the current level of motivation. The incentive pay-system diminishes as personal developement and increased responsibility becomes more of a crucial factor as the employee climbs the career ladder at Tele2. Furthermore, by rewarding performance that contributes to the overall goals of the organization, in this case increased revenue, goal congruence is created between the employee and the organization. This means that the employee is encouraged to work towards the organizational goals in order to have the opportunity to reach their individual goals

Transient chirp in high speed photonic crystal quantum dots lasers with controlled spontaneous emission

We report on a series of experiments on the dynamics of spontaneous emission controlled nanolasers. The laser cavity is a photonic crystal slab cavity, embedding self-assembled quantum dots as gain material. The implementation of cavity electrodynamics effects increases significantly the large signal modulation bandwidth, with measured modulation speeds of the order of 10 GHz while keeping an extinction ratio of 19 dB. A linear transient wavelength shift is reported, corresponding to a chirp of less than 100 pm for a 35-ps laser pulse. We observe that the chirp characteristics are independent of the repetition rate of the laser up to 10 GHz

Towards Structured Evaluation of Deep Neural Network Supervisors

Deep Neural Networks (DNN) have improved the quality of several non-safety related products in the past years. However, before DNNs should be deployed to safety-critical applications, their robustness needs to be systematically analyzed. A common challenge for DNNs occurs when input is dissimilar to the training set, which might lead to high confidence predictions despite proper knowledge of the input. Several previous studies have proposed to complement DNNs with a supervisor that detects when inputs are outside the scope of the network. Most of these supervisors, however, are developed and tested for a selected scenario using a specific performance metric. In this work, we emphasize the need to assess and compare the performance of supervisors in a structured way. We present a framework constituted by four datasets organized in six test cases combined with seven evaluation metrics. The test cases provide varying complexity and include data from publicly available sources as well as a novel dataset consisting of images from simulated driving scenarios. The latter we plan to make publicly available. Our framework can be used to support DNN supervisor evaluation, which in turn could be used to motive development, validation, and deployment of DNNs in safety-critical applications.Comment: Preprint of paper accepted for presentation at The First IEEE International Conference on Artificial Intelligence Testing, April 4-9, 2019, San Francisco East Bay, California, US

Quantification of microscopic diffusion anisotropy disentangles effects of orientation dispersion from microstructure: Applications in healthy volunteers and in brain tumors

AbstractThe anisotropy of water diffusion in brain tissue is affected by both disease and development. This change can be detected using diffusion MRI and is often quantified by the fractional anisotropy (FA) derived from diffusion tensor imaging (DTI). Although FA is sensitive to anisotropic cell structures, such as axons, it is also sensitive to their orientation dispersion. This is a major limitation to the use of FA as a biomarker for “tissue integrity”, especially in regions of complex microarchitecture. In this work, we seek to circumvent this limitation by disentangling the effects of microscopic diffusion anisotropy from the orientation dispersion.The microscopic fractional anisotropy (μFA) and the order parameter (OP) were calculated from the contrast between signal prepared with directional and isotropic diffusion encoding, where the latter was achieved by magic angle spinning of the q-vector (qMAS). These parameters were quantified in healthy volunteers and in two patients; one patient with meningioma and one with glioblastoma. Finally, we used simulations to elucidate the relation between FA and μFA in various micro-architectures.Generally, μFA was high in the white matter and low in the gray matter. In the white matter, the largest differences between μFA and FA were found in crossing white matter and in interfaces between large white matter tracts, where μFA was high while FA was low. Both tumor types exhibited a low FA, in contrast to the μFA which was high in the meningioma and low in the glioblastoma, indicating that the meningioma contained disordered anisotropic structures, while the glioblastoma did not. This interpretation was confirmed by histological examination.We conclude that FA from DTI reflects both the amount of diffusion anisotropy and orientation dispersion. We suggest that the μFA and OP may complement FA by independently quantifying the microscopic anisotropy and the level of orientation coherence

Landscape Analysis for the Specimen Data Refinery

This report reviews the current state-of-the-art applied approaches on automated tools, services and workflows for extracting information from images of natural history specimens and their labels. We consider the potential for repurposing existing tools, including workflow management systems; and areas where more development is required. This paper was written as part of the SYNTHESYS+ project for software development teams and informatics teams working on new software-based approaches to improve mass digitisation of natural history specimens

Plasma neurofilament light protein correlates with diffusion tensor imaging metrics in frontotemporal dementia

Neurofilaments are structural components of neurons and are particularly abundant in highly myelinated axons. The levels of neurofilament light chain (NfL) in both cerebrospinal fluid (CSF) and plasma have been related to degeneration in several neurodegenerative conditions including frontotemporal dementia (FTD) and NfL is currently considered as the most promising diagnostic and prognostic fluid biomarker in FTD. Although the location and function of filaments in the healthy nervous system suggests a link between increased NfL and white matter degeneration, such a claim has not been fully elucidated in vivo, especially in the context of FTD. The present study provides evidence of an association between the plasma levels of NfL and white matter involvement in behavioral variant FTD (bvFTD) by relating plasma concentration of NfL to diffusion tensor imaging (DTI) metrics in a group of 20 bvFTD patients. The results of both voxel-wise and tract specific analysis showed that increased plasma NfL concentration is associated with a reduction in fractional anisotropy (FA) in a widespread set of white matter tracts including the superior longitudinal fasciculus, the fronto-occipital fasciculus the anterior thalamic radiation and the dorsal cingulum bundle. Plasma NfL concentration also correlated with cortical thinning in a portion of the right medial prefrontal cortex and of the right lateral orbitofrontal cortex. These results support the hypothesis that blood NfL levels reflect the global level of neurodegeneration in bvFTD and help to advance our understanding of the association between this blood biomarker for FTD and the disease process

Mechanisms of Cognitive Impairment in Cerebral Small Vessel Disease: Multimodal MRI Results from the St George's Cognition and Neuroimaging in Stroke (SCANS) Study.

Cerebral small vessel disease (SVD) is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI) is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115), and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50). On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD