A PhD research project on safety risk assessment of complex changes to railway infrastructure and vehicles

This study investigates the risk assessment of railway changes in an interconnected environment. Systems are a collection of subsystems and parts, and this thesis develops a new method, the Combined Assessment Method (CAM), to analyse them. CAM potentially applies to many industries, including aviation, defence and nuclear, where there is a requirement to assess system safety objectively. The railway is a specific case of a closely coupled socio-technical system of critical physical interfaces between systems and a stringent example of systems in other industries. The Author has carried out: an assessment of current techniques, a review of relevant literature, a survey of risk assessment practitioners, an appraisal of current methods, and a review of accident data to identify current accident characteristics. CAM incorporates established assessment techniques to perform subsystem analysis. Subsystem results are combined using systems engineering methods in a novel way producing an overall risk assessment for a system, which incorporates emergent behaviours. The assurance of CAM is through a case study and two test cases. It uses safety performance, ease of use, and economic saving criteria to judge success. Illustrative studies include a metro system, indicating that CAM is potentially a process and is application-independent. Furthermore, test cases illustrate that CAM combines the risks from multiple parts of a whole system into overall risks. Finally, test cases measure the verification through a match between the findings of official incident reports and the CAM output. This thesis is the first step to creating CAM as a fully-fledged system safety risk analysis method. Further work is proposed to take CAM forward and address identified weaknesses. Finally, suggestions have been made for further work to “productionize” CAM to increase the likelihood that practitioners in the field will use CAM

Työympäristöt NewSpace-tuotekehityksessä – Tapaustutkimus nanosatelliittiyrityksessä

Workspaces, along with work culture, are constantly evolving. The ongoing trend of creating inviting working environments and increasing productivity by fulfilling individual needs is reaching to all the fields, including the most conventional ones, such as space industry. During the past few decades, this traditionally inflexible and conservative industry has seen an emerging transition towards agile and market-driven direction. In the professional world, this growing phenomenon of commercialisation and privatization of space technology is referred as NewSpace. The purpose of this study was to determine what kind of working environment supports NewSpace. To get there, differences between conventional space industry and NewSpace were highlighted, serving as a basis of needs for entrepreneurial space activities. Additionally, the concept of working environment was analysed to determine the attributes which create a desirable basis for working. These needs and desirables provided a framework of working environment design for a NewSpace company. The study starts with a comprehensive literature review and proceeds to practical part, consisting of observations, interviews and a practical re-arrangement setup for the case company, Reaktor Space Lab (RSL), a new-found startup that spun off from a university project. Emphasis was put to measurability and its difficulties, therefore an online survey was conducted and the results were analysed. The goal of the survey was not only to evaluate the current state of RSL, but to assess the importance of comprehensive working environment design and evaluate its relevance to NewSpace industry. The study produced findings that can be summarized into following statements: 1) In space industry, modern and comprehensive design of working environment is only seldom taken into consideration and it is often seen as a cost rather than necessity, 2) workspace as such does not provide an extensive solution for environmental change, therefore emphasis should be put into understanding case-specific needs and approaching organisational change on a systematic level and 3) Working environment design does have impact to NewSpace companies, however the approach applies only to certain sort of space projects, so it shouldn’t be taken as a platitude in space industry. Based on these findings, this thesis provides fundamental suggestions for space technology companies that aim to develop its procedures towards agile NewSpace methodology. In addition, practical improvement proposals for RSL are proposed.Työpaikat ja työkulttuuri kehittyvät jatkuvasti. Kutsuvien, käyttäjien tarpeita mukailevien työympäristöjen luominen on yleistynyt alaan katsomatta – myös perinteisemmillä aloilla, kuten avaruusteollisuudessa. Tämä verrattain jäykkä ja täsmällinen teollisuudenhaara on kohdannut uuden ilmiön, jossa yksityiset avaruustoimijat yhdistävät ketterät toimintatavat ja markkinalähtöisyyden. Tästä yrittäjähenkisestä lähestymistavasta käytetään nimitystä NewSpace. Tämän diplomityön tarkoituksena oli selvittää, minkälainen työympäristö tukee NewSpace-toimintaa. Tämän määrittelemiseksi selvitettiin perinteisen avaruusteollisuuden ja NewSpace-tavan eroja, minkä perusteella määriteltiin kaupallisen avaruustoiminnan tarpeet. Lisäksi määritettiin työntekoa tukevan ympäristön ominaisuuksia tutkimalla modernia työympäristöä konseptitasolla. Näiden tarpeiden ja toivottujen ominaisuuksien avulla luotiin puitteet NewSpace-työympäristölle. Tutkimus alkaa kirjallisuuskatsauksella, joka luo pohjan käytännön osiolle. Tutkimusmetodeina käytetään kirjallisuuskatsauksen lisäksi havainnointia, haastatteluita sekä käytännön uudelleenjärjestelyjä kohdeyrityksessä Reaktor Space Lab. Tämän yliopistoprojektista liikkeelle lähteneen pienyrityksen työympäristöä ja sen muutoksia mitataan online-kyselyllä, jonka avulla saatiin tuloksia ja johtopäätöksiä sekä kohdeyrityksestä, että avaruusyrittäjyydestä yleisellä tasolla. Tutkimustuloksista tehtiin yhteenvetoja, jotka voidaan tiivistää seuraavasti: 1) Avaruusalalla otetaan harvoin huomioon työympäristö kattavasti siten, että se tukee henkilöstön tarpeita ja organisaation yhteisiä tavoitteita. 2) Työtilat eivät sellaisenaan tue ympäristön muutosta, joten muutoksessa tulee ottaa huomioon tapauskohtaiset organisaation ja yksilöiden tarpeet sekä toiminnan tavoitteet. 3) Kattavalla työympäristösuunnittelulla on vaikutusta NewSpace-toimintaan, mutta NewSpace ei sellaisenaan sovellu kaikkeen avaruustoimintaan. Tuloksien perusteella laadittiin ehdotus yleisistä toimintatavoista, jonka avulla voidaan kehittää työympäristö tukemaan ketterää NewSpace-avaruustoimintaa. Lisäksi tuotiin esille ehdotuksia kohdeyrityksen työympäristön kehittämiselle

A Formal Verification Environment for Use in the Certification of Safety-Related C Programs

In this thesis the design of an environment for the formal verification of functional properties of safety-related software written in the programming language C is described. The focus lies on the verification of (primarily) geometric computations. We give an overview of the applicable regulations for safety-related software systems. We define a combination of higher-order logic as formalised in the theorem prover Isabelle and a specification language syntactically based on C expressions. The language retains the mathematical character of higher-level specifications in code specifications. A memory model for C is formalised which is appropriate to model low-level memory operations while keeping the entailed verification overhead in tolerable bounds. Finally, a Hoare style proof calculus is devised so that correctness proofs can be performed in one integrated framework. The applicability of the approach is demonstrated by describing its use in an industrial project

Biohacking and code convergence : a transductive ethnography

Cette thèse se déploie dans un espace de discours et de pratiques revendicatrices, à l’inter- section des cultures amateures informatiques et biotechniques, euro-américaines contempo- raines. La problématique se dessinant dans ce croisement culturel examine des métaphores et analogies au coeur d’un traffic intense, au milieu de voies de commmunications imposantes, reliant les technologies informatiques et biotechniques comme lieux d’expression médiatique. L’examen retrace les lignes de force, les médiations expressives en ces lieux à travers leurs manifestations en tant que codes —à la fois informatiques et génétiques— et reconnaît les caractères analogiques d’expressivité des codes en tant que processus de convergence. Émergeant lentement, à partir des années 40 et 50, les visions convergentes des codes ont facilité l’entrée des ordinateurs personnels dans les marchés, ainsi que dans les garages de hackers, alors que des bricoleurs de l’informatique s’en réclamaient comme espace de liberté d’information —et surtout d’innovation. Plus de cinquante ans plus tard, l’analogie entre codes informatiques et génétiques sert de moteur aux revendications de liberté, informant cette fois les nouvelles applications de la biotechnologie de marché, ainsi que l’activité des biohackers, ces bricoleurs de garage en biologie synthétique. Les pratiques du biohacking sont ainsi comprises comme des individuations : des tentatives continues de résoudre des frictions, des tensions travaillant les revendications des cultures amateures informatiques et biotechniques. Une des manières de moduler ces tensions s’incarne dans un processus connu sous le nom de forking, entrevu ici comme l’expérience d’une bifurcation. Autrement dit, le forking est ici définit comme passage vers un seuil critique, déclinant la technologie et la biologie sur plusieurs modes. Le forking informe —c’est-à-dire permet et contraint— différentes vi- sions collectives de l’ouverture informationnelle. Le forking intervient aussi sur les plans des iii semio-matérialités et pouvoirs d’action investis dans les pratiques biotechniques et informa- tiques. Pris comme processus de co-constitution et de différentiation de l’action collective, les mouvements de bifurcation invitent les trois questions suivantes : 1) Comment le forking catalyse-t-il la solution des tensions participant aux revendications des pratiques du bioha- cking ? 2) Dans ce processus de solution, de quelles manières les revendications changent de phase, bifurquent et se transforment, parfois au point d’altérer radicalement ces pratiques ? 3) Quels nouveaux problèmes émergent de ces solutions ? L’effort de recherche a trouvé ces questions, ainsi que les plans correspondants d’action sémio-matérielle et collective, incarnées dans trois expériences ethnographiques réparties sur trois ans (2012-2015) : la première dans un laboratoire de biotechnologie communautaire new- yorkais, la seconde dans l’émergence d’un groupe de biotechnologie amateure à Montréal, et la troisième à Cork, en Irlande, au sein du premier accélérateur d’entreprises en biologie synthétique au monde. La logique de l’enquête n’est ni strictement inductive ou déductive, mais transductive. Elle emprunte à la philosophie de la communication et de l’information de Gilbert Simondon et découvre l’épistémologie en tant qu’acte de création opérant en milieux relationnels. L’heuristique transductive offre des rencontres inusitées entre les métaphores et les analogies des codes. Ces rencontres étonnantes ont aménagé l’expérience de la conver- gence des codes sous forme de jeux d’écritures. Elles se sont retrouvées dans la recherche ethnographique en tant que processus transductifs.This dissertation examines creative practices and discourses intersecting computer and biotech cultures. It queries influential metaphors and analogies on both sides of the inter- section, and their positioning of biotech and information technologies as expression media. It follows mediations across their incarnations as codes, both computational and biological, and situates their analogical expressivity and programmability as a process of code conver- gence. Converging visions of technological freedom facilitated the entrance of computers in 1960’s Western hobbyist hacker circles, as well as in consumer markets. Almost fifty years later, the analogy drives claims to freedom of information —and freedom of innovation— from biohacker hobbyist groups to new biotech consumer markets. Such biohacking practices are understood as individuations: as ongoing attempts to resolve frictions, tensions working through claims to freedom and openness animating software and biotech cultures. Tensions get modulated in many ways. One of them, otherwise known as “forking,” refers here to a critical bifurcation allowing for differing iterations of biotechnical and computa- tional configurations. Forking informs —that is, simultaneously affords and constrains— differing collective visions of openness. Forking also operates on the materiality and agency invested in biotechnical and computational practices. Taken as a significant process of co- constitution and differentiation in collective action, bifurcation invites the following three questions: 1) How does forking solve tensions working through claims to biotech freedom? 2) In this solving process, how can claims bifurcate and transform to the point of radically altering biotech practices? 3) what new problems do these solutions call into existence? This research found these questions, and both scales of material action and agency, in- carnated in three extensive ethnographical journeys spanning three years (2012-2015): the first in a Brooklyn-based biotech community laboratory, the second in the early days of a biotech community group in Montreal, and the third in the world’s first synthetic biology startup accelerator in Cork, Ireland. The inquiry’s guiding empirical logic is neither solely deductive or inductive, but transductive. It borrows from Gilbert Simondon’s philosophy of communication and information to experience epistemology as an act of analogical creation involving the radical, irreversible transformation of knower and known. Transductive heuris- tics offer unconvential encounters with practices, metaphors and analogies of code. In the end, transductive methods acknowledge code convergence as a metastable writing games, and ethnographical research itself as a transductive process

Operational research:methods and applications

Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order

LIPIcs, Volume 244, ESA 2022, Complete Volume

LIPIcs, Volume 244, ESA 2022, Complete Volum