On engineering reliability concepts and biological aging

Some stochastic approaches to biological aging modeling are studied. We assume that an organism acquires a random resource at birth. Death occurs when the accumulated dam-age (wear) exceeds this initial value, modeled by the discrete or continuous random vari-ables. Another source of death of an organism is also taken into account, when it occurs as a consequence of a shock or of a demand for energy, which is a generalization of the Strehler-Mildwan’s model (1960). Biological age based on the observed degradation is also defined. Finally, aging properties of repairable systems are discussed. We show that even in the case of imperfect repair, which is certainly the case for organisms, aging slows down with age and eventually can even fade out. This presents another possible explanation for the human mortality rate plateaus.mortality

Mortality in varying environment

An impact of environment on mortality, similar to survival analysis, is often modeled by the proportional hazards model, which assumes the corresponding comparison with a baseline environment. This model describes the memory-less property, when the mortality rate at a given instant of time depends only on the environment at this in-stant of time and does not depend on the history. In the presence of degradation the assumption of this kind is usually unrealistic and history-dependent models should be considered. The simplest stochastic degradation model is the accelerated life model. We discuss these models for the cohort setting and apply the developed approach to the period setting for the case when environment (stress) is modeled by the functions with switching points (jumps in the level of the stress).

On Distributed Storage Codes

Distributed storage systems are studied. The interest in such system has become relatively wide due to the increasing amount of information needed to be stored in data centers or different kinds of cloud systems. There are many kinds of solutions for storing the information into distributed devices regarding the needs of the system designer. This thesis studies the questions of designing such storage systems and also fundamental limits of such systems. Namely, the subjects of interest of this thesis include heterogeneous distributed storage systems, distributed storage systems with the exact repair property, and locally repairable codes. For distributed storage systems with either functional or exact repair, capacity results are proved. In the case of locally repairable codes, the minimum distance is studied. Constructions for exact-repairing codes between minimum bandwidth regeneration (MBR) and minimum storage regeneration (MSR) points are given. These codes exceed the time-sharing line of the extremal points in many cases. Other properties of exact-regenerating codes are also studied. For the heterogeneous setup, the main result is that the capacity of such systems is always smaller than or equal to the capacity of a homogeneous system with symmetric repair with average node size and average repair bandwidth. A randomized construction for a locally repairable code with good minimum distance is given. It is shown that a random linear code of certain natural type has a good minimum distance with high probability. Other properties of locally repairable codes are also studied.Siirretty Doriast

An Exploration of Artificiality

The following explores the artificiality of human artifacts. To talk of artifacts, we must avoid ontologizing. Ontology ignores human participation in its construction and describing artifacts as if their descriptions had nothing to do with it contradicts the idea of their artificiality. Instead, I will explore the nature of artifacts from the perspective of human-centered design and with culture-sensitive conceptions in mind. Exploring artifacts from this perspective offers scholars and practitioners a fascinating field of inquiry. Following are six closely connected mini essays about artifacts, starting with the use of the word “artifact” and ending with the virtual worlds that artifacts can bring forth

Frontiers of Adaptive Design, Synthetic Biology and Growing Skins for Ephemeral Hybrid Structures

The history of membranes is one of adaptation, from the development in living organisms to man-made versions, with a great variety of uses in temporary design: clothing, building, packaging, etc. Being versatile and simple to integrate, membranes have a strong sustainability potential, through an essential use of material resources and multifunctional design, representing one of the purest cases where “design follows function.” The introduction of new engineered materials and techniques, combined with a growing interest for Nature-inspired technologies are progressively merging man-made artifacts and biological processes with a high potential for innovation. This chapter introduces, through a number of examples, the broad variety of hybrid membranes in the contest of experimental Design, Art and Architecture, categorized following two different stages of biology-inspired approach with the aim of identifying potential developments. Biomimicry, is founded on the adoption of practices from nature in architecture though imitation: solutions are observed on a morphological, structural or procedural level and copied to design everything from nanoscale materials to building technologies. Synthetic biology relies on hybrid procedures mixing natural and synthetic materials and processes

“We Need a Showing of All Hands”: Technological Utopianism in \u3cem\u3eMAKE\u3c/em\u3e Magazine

Make magazine is a quarterly publication focused on do-it-yourself projects involving technology and innovation. The magazine also sponsors a biannual event, the Maker Faire, that brings “makers” together to share their knowledge. As a strategy for building audience loyalty and identification with the magazine, the Make products are skillfully crafted. However, they also invoke ideals such as environmentalism and nationalism in a potent mix that not only engages readers, but also represents an additional cultural demonstration of the phenomenon of technological utopianism

To repair or not to repair: an investigation of the factors influencing prosumer repair propensity

The Circular Economy is a sustainable system of production and consumption that aims to minimise waste, emissions and energy leakages through a closed system. Repair is one of the strategies to facilitate the transition towards the Circular Economy (CE). Repair is also a behaviour that the prosumer can adopt and enact in collaboration with other citizens in society. The inclination to repair, called explicitly in this thesis, ‘the prosumer’s propensity to repair’ is influenced and affected by a myriad of complex and inter-related elements. Those elements need to be further investigated to support the actors involved in the transition towards the CE to develop interventions to support the prosumer to repair further. The investigation was set in an extreme case scenario by choosing to engage with individuals who, by their affiliation with pro-environmental organisations, appear to be more inclined to engage with pro-environmental behaviours. The investigation focuses on them trying to repair small electrical items because there have been conflicting results in previous research, on the extent to which environmental concerns influence Prosumer Repair Propensity. The literature explores Repair as an activitiy to be embraced by prosumers and strategy to facilitate the transition towards a CE. The review discusses the role, and capacity of the prosumers in to both produce and consume value to support the transition. The literature explores the role of Design in developing solutions to extend product lifespan and to influence prosumer behaviour. The literature in the field of Design for Sustainable Behaviour emphasises the significance of investigating prosumer behaviour before developing interventions. As a result, the literature reviews past research on the factors influencing Prosumer Repair Propensity and behavioural frameworks that could support the investigation. The Theory of Trying and the Transtheoretical model of Change are selected as tools for understanding prosumer repair behaviour as a multi-dimensional object.Two studies are undertaken to meet the research objectives set out for the investigation. Two hundred and eight respondents completed a survey for the Survey study. For the Prosumer study, 10 participants completed a survey, a semi-structured interview and two video-elicitation exercises. The analysis and integration of the findings from the Survey study and Prosumer study helped to consolidate five sets of findings. The first set of findings presents the range of factors influencing Prosumer Repair Propensity; it includes the most significant factors to support the engagement with repair practice and the most critical factors to successfully repair an item. The second set of findings examines the attitudes towards trying to repair. The third set of findings presents the processes of change affecting the prosumer to repair. The fourth and fifth set of findings presents the repair process and considers how the factors and attitudes influence the prosumer at different stages of the repair process. From the findings, suggestions are given on the prosumer actions that can be adopted to support the transition towards the CE. The thesis finally closes on the limitations of the research project and recommends areas for further research to support the prosumer to change.</div