Computer data base assessment of masonry bridges.

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Evaluation of 1-D and 2-D hydraulic models for designing and assessing fullspan stream crossings

This project compared design decisions and hydraulic analyses of full-span stream crossings using one- and two-dimensional (1-D and 2-D) hydraulic models. The project was initiated by the California Department of Transportation’s interest in moving from 1-D to 2-D hydraulic modeling and by the Federal Highways Administration’s support for adopting SRH-2D (Sedimentation and River Hydraulics-2D developed by the US Bureau of Reclamation) in Aquaveo, LLC’s Surface-water Modeling System as their standard design model. Two-dimensional hydraulic models calculate more detailed water depths and velocities than 1-D models, which can better identify fish passage conditions, areas of potential scour or deposition, and aquatic organism habitat characteristics. The project evaluated two recently constructed full-span (channel spanning) crossings that were designed based on HEC-RAS 1-D model analysis and constructed in 2017. The 1-D hydraulic models were not available for either of the projects, so the 1-D model results within the final project reports were used for comparison with 2-D model results completed for this project. Little Mill Creek crossing is a bridge with five rock weirs installed in the channel below located in Del Norte County, California. North Fork Ryan Creek is located in Mendocino County and is a box culvert with inlet and outlet headwalls and rock weirs installed both upstream and downstream of the crossing. The sites were re-surveyed in 2019 and 2020, and current conditions were modeled using SRH-2D. Current site conditions and 2-D model depth and velocity results were used to identify design elements that may have been designed differently using a 2-D model analysis in an effort to inform future full-span crossing design processes. Using local 2-D model velocities for bank rock slope protection or riprap (RSP) sizing and abutment scour calculations resulted in differences in RSP size recommendations and abutment scour depth estimations. For Little Mill Creek Bridge, the RSP was estimated to be currently undersized, while at North Fork Ryan Creek crossing the RSP was oversized compared to the 2-D analysis based calculations. The local velocities and water depths available from 2-D model results provide greater spatial detail of the estimated forces experienced at the banks and abutments and account for local turbulence. In terms of practicality, model efficiency and computing power continue to increase, making 2-D modeling more accessible. Computer processing time was found to increase linearly with the number of mesh elements so model run times are not likely to limit 2-D modeling for stream crossing sites. Sites with expansive floodplains could experience longer run times if detailed results, and therefore more mesh elements, are needed on the floodplain

Investigating an ‘institutional partnership’ collaborating to develop a funded project into a sustainable work-integration social enterprise (WISE)

This paper reports a research study that examined a partnership between a regional social enterprise development agency and a university as they collaborated to develop a work-integration social enterprise (WISE) in the UK. Participants were members of the board of directors, steering group and the programme delivery and administration staff. The research elicited participant perceptions of the development of the partnership and the WISE over a period of eighteen months. Semi-structured interviews were conducted with participants in three phases: ‘early’, ‘middle’ and ‘late’. Results revealed the problems experienced by the partnership, which ultimately inhibited the development of a sustainable WIS

The Rise of Decentralized Autonomous Organizations: Coordination and Growth within Cryptocurrencies

The rise of cryptocurrencies such as Bitcoin is driving a paradigm shift in organization design. Their underlying blockchain technology enables a novel form of organizing, which I call the “decentralized autonomous organization” (DAO). This study explores how tasks are coordinated within DAOs that provide decentralized and open payment systems that do not rely on centralized intermediaries (e.g., banks). Guided by a Bitcoin pilot case study followed by a three-stage research design that uses both qualitative and quantitative data, this inductive study examines twenty DAOs in the cryptocurrency industry to address the following question: How are DAOs coordinated to enable growth? Results from the pilot study suggest that task coordination within DAOs is enabled by distributed consensus mechanisms at various levels. Further, findings from interview data reveal that DAOs coordinate tasks through “machine consensus” and “social consensus” mechanisms that operate at varying degrees of decentralization. Subsequent fuzzy-set qualitative comparative analyses (fsQCA), explaining when DAOs grow or decline, show that social consensus mechanisms can partially substitute machine consensus mechanisms in less decentralized DAOs. Taken together, the results unpack how DAO growth relies on the interplay between machine consensus, social consensus, and decentralization mechanisms. To conclude, I formulate three propositions to outline a theory of DAO coordination and discuss how this novel form of organizing calls for a revision of our conventional understanding of task coordination and organizational growth

An Introduction to Causal Inference Methods for Observational Human-Robot Interaction Research

Quantitative methods in Human-Robot Interaction (HRI) research have primarily relied upon randomized, controlled experiments in laboratory settings. However, such experiments are not always feasible when external validity, ethical constraints, and ease of data collection are of concern. Furthermore, as consumer robots become increasingly available, increasing amounts of real-world data will be available to HRI researchers, which prompts the need for quantative approaches tailored to the analysis of observational data. In this article, we present an alternate approach towards quantitative research for HRI researchers using methods from causal inference that can enable researchers to identify causal relationships in observational settings where randomized, controlled experiments cannot be run. We highlight different scenarios that HRI research with consumer household robots may involve to contextualize how methods from causal inference can be applied to observational HRI research. We then provide a tutorial summarizing key concepts from causal inference using a graphical model perspective and link to code examples throughout the article, which are available at https://gitlab.com/causal/causal_hri. Our work paves the way for further discussion on new approaches towards observational HRI research while providing a starting point for HRI researchers to add causal inference techniques to their analytical toolbox.Comment: 28 page

Changing States: Using State-and-Transition Models to Evaluate Channel Evolution Following Dam Removal Along the Clark Fork River, Montana

Located just east of Missoula, Montana, Milltown Dam stood from 1908 to 2008 immediately downstream of the Clark Fork River’s confluence with the Blackfoot River. After the discovery of arsenic-contaminated groundwater in the nearby community of Milltown, as well as extensive deposits of contaminated sediment in the dam’s upstream reservoir, in 1981, the area was designated a Superfund site – along with much of the Upper Clark Fork Watershed. This motivated the eventual decision to remove the dam, perform environmental remediation, and reconstruct approximately five kilometers of the Clark Fork River and its floodplain. This study is part conceptual and part empirical. It describes a state-and-transition framework equipped to investigate channel evolution as well as the adjustment trajectories of other socio-biophysical landscapes. This framework is then applied to understand the post-restoration channel evolution of the Clark Fork River’s mainstem, secondary channels, and floodplain. Adopting a state-and-transition framework to conceptualize landscape evolution lets environmental managers more effectively anticipate river response under multiple disturbence scenarios and therefore use more improvisational and adaptive management techniques that do not attempt to guide the landscape toward a single and permanent end state. State-and-transition models can also be used to highlight the spatially explicit patterns of complex biophysical response. The state-and-transition models developed for the Clark Fork River demonstrate the possibility of multiple evolutionary trajectories. Neither the secondary channels nor the main channel have responded in a linear, monotonic fashion, and future responses will be contingent upon hydrogeomorphic and climatic variability and chance disturbances. The biogeomorphic adjustments observed so far suggest divergent evolutionary trajectories and that in some instances the long-term fates of the mainstem, floodplain, and secondary channels are inescapably enmeshed with one another

Coopetition in an open-source way : lessons from mobile and cloud computing infrastructures

An increasing amount of technology is no longer developed in-house. Instead, we are in a new age where technology is developed by a networked community of individuals and organizations, who base their relations to each other on mutual interest. Advances arising from research in platforms, ecosystems, and infrastructures can provide valuable knowledge for better understanding and explaining technology development among a network of firms. More surprisingly, recent research suggests that technology can be jointly developed by rival competing firms in an open-source way. For instance, it is known that the mobile device makers Apple and Samsung continued collaborating in open-source projects while running expensive patent wars in the courts. On top of multidisciplinary theory in open-source software, cooperation among competitors (aka coopetition) and digital infrastructures, I (and my coauthors) explored how rival firms cooperate in the joint development of open-source infrastructures. While assimilating a wide variety of paradigms and analytical approaches, this doctoral research combined the qualitative analysis of naturally occurring data (QA) with the mining of software repositories (MSR) and social network analysis (SNA) within a set of case studies. By turning to the mobile and cloud computing industries in general, and the WebKit and OpenStack opensource infrastructures in particular, we found out that qualitative ethnographic materials, combined with social network visualizations, provide a rich medium that enables a better understanding of competitive and cooperative issues that are simultaneously present and interconnected in open-source infrastructures. Our research contributes back to managerial literature in coopetition strategy, but more importantly to Information Systems by addressing both cooperation and competition within the development of high-networked open-source infrastructures.Yhä suurempaa osaa teknologiasta ei enää kehitetä organisaatioiden omasta toimesta. Sen sijaan, olemme uudella aikakaudella jossa teknologiaa kehitetään verkostoituneessa yksilöiden ja organisaatioiden yhteisössä, missä toimitaan perustuen yhteiseen tavoitteeseen. Alustojen, ekosysteemien ja infrastruktuurien tutkimuksen tulokset voivat tuottaa arvokasta tietämystä teknologian kehittämisestä yritysten verkostossa. Erityisesti tuore tutkimustieto osoittaa että kilpailevat yritykset voivat yhdessä kehittää teknologiaa avoimeen lähdekoodiin perustuvilla käytännöillä. Esimerkiksi tiedetään että mobiililaitteiden valmistajat Apple ja Samsung tekivät yhteistyötä avoimen lähdekoodin projekteissa ja kävivät samaan aikaan kalliita patenttitaistoja eri oikeusfoorumeissa. Perustuen monitieteiseen teoriaan avoimen lähdekoodin ohjelmistoista, yhteistyöstä kilpailijoiden kesken (coopetition) sekä digitaalisista infrastruktuureista, minä (ja kanssakirjoittajani) tutkimme miten kilpailevat yritykset tekevät yhteistyötä avoimen lähdekoodin infrastruktuurien kehityksessä. Sulauttaessaan runsaan joukon paradigmoja ja analyyttisiä lähestymistapoja case-joukon puitteissa, tämä väitöskirjatutkimus yhdisti luonnollisesti esiintyvän datan kvantitatiivisen analyysin ohjelmapakettivarastojen louhintaan ja sosiaalisten verkostojen analyysiin. Tutkiessamme mobiili- ja pilvipalveluiden teollisuudenaloja yleisesti, ja WebKit ja OpenStack avoimen lähdekoodin infrastruktuureja erityisesti, havaitsimme että kvalitatiiviset etnografiset materiaalit yhdistettyinä sosiaalisten verkostojen visualisointiin tuottavat rikkaan aineiston joka mahdollistaa avoimen lähdekoodin infrastruktuuriin samanaikaisesti liittyvien kilpailullisten ja yhteistyökuvioiden hyvän ymmärtämisen. Tutkimuksemme antaa oman panoksensa johdon kirjallisuuteen coopetition strategy -alueella, mutta sitäkin enemmän tietojärjestelmätieteeseen, läpikäymällä sekä yhteistyötä että kilpailua tiiviisti verkostoituneessa avoimen lähdekoodin infrastruktuurien kehitystoiminnassaUma crescente quantidade de tecnologia não é desenvolvida internamente por uma só organização. Em vez disso, estamos em uma nova era em que a tecnologia é desenvolvida por uma comunidade de indivíduos e organizações que baseiam suas relações umas com as outras numa rede de interesse mútuo. Os avanços teórico decorrentes da pesquisa em plataformas computacionais, ecossistemas e infraestruturas digitais fornecem conhecimentos valiosos para uma melhor compreensão e explicação do desenvolvimento tecnológico por uma rede de multiplas empresas. Mais surpreendentemente, pesquisas recentes sugerem que tecnologia pode ser desenvolvida conjuntamente por empresas rivais concorrentes e de uma forma aberta (em código aberto). Por exemplo, sabe-se que os fabricantes de dispositivos móveis Apple e Samsung continuam a colaborar em projetos de código aberto ao mesmo tempo que se confrontam em caras guerras de patentes nos tribunais. Baseados no conhecimento científico de software de código aberto, de cooperação entre concorrentes (também conhecida como coopetição) e de infraestruturas digitais, eu e os meus co-autores exploramos como empresas concorrentes cooperam no desenvolvimento conjunto de infraestruturas de código aberto. Ao utilizar uma variedade de paradigmas e abordagens analíticas, esta pesquisa de doutoramento combinou a análise qualitativa de dados de ocorrência natural (QA) com a análise de repositórios de softwares (MSR) e a análise de redes sociais (SNA) dentro de um conjunto de estudos de casos. Ao investigar as industrias de technologias móveis e de computação em nuvem em geral, e as infraestruturas em código aberto WebKit e OpenStack, em particular, descobrimos que o material etnográfico qualitativo, combinado com visualizações de redes sociais, fornece um meio rico que permite uma melhor compreensão das problemas competitivos e cooperativos que estão simultaneamente presentes e interligados em infraestruturas de código aberto. A nossa pesquisa contribui para a literatura em gestão estratégica e coompetição, mas mais importante para literatura em Sistemas de Informação, abordando a cooperação e concorrência no desenvolvimento de infraestruturas de código aberto por uma rede the indivíduos e organizações em interesse mútuo