Improving GIS-based Models for Bicycling Speed Estimations

For reasons ranging from carbon emissions to public health, traffic planning as well as urban design aim to increase the modal share of bicycling on the cost of fossil fuel based commuting. However, most urban and traffic planning practices handle bicycling very schematically. Typically, tools for analyzing bicycling rely on fixed speed templates, paying little attention to the fact that bicycling speeds vary a lot depending on type of bicyclist and explicit properties of bicycle routes and the contexts of those routes. As long as very simplified assumptions form the basis for analysis, it is hard to make reliable comparisons of alternative proposals of urban form layouts and infrastructure investments. Therefore, from the perspective of traffic planning as well as from the perspective of urban planning and design, there is need for more refined methods for predicting bicycling speeds. This paper presents an outline for such a bicycling speed modelling tool.\ua0This work combines tools and measures from two recent bikeability modelling studies. One is an urban form based study of bicycle route networks, grasping issues related to geometrical directness of routes and various measures of accessibility and density. The other calculates likely speeds based on horizontal and vertical geometry of routes. The latter model uses an advanced statistical model to grasp dependence between adjacent road segments. The new combined model is estimated using GPS tracking of real bicycle trips in combination with GIS-based data of bicycle route networks and of the local contexts of the routes.\ua0More in detail, the new model includes parameters estimated for the following covariates:\ua0• route geometry (by slope and by horizontal curvature)• intersection impedances derived from type of junction (by presence of signal-crossings and by kinds of crossing streets categorized by amounts of traffic)• type of bicycle-route (bicycle lane in street, separate bicycle lane, combined walk- and bicycle lane or mixed-use streets)\ua0• kind of surface (smooth surface or gravel)• density of entrances along route (a proxy for slower bicycling due to urban/vibrant context)The modelling is based on so-called Markov-dependence, including that the covariates are used to estimate continuous speed profiles along entire routes, and not only average speed levels on road segments seen separate and independent. Through this, the new model results in more realistic speed estimations than the previous models. The paper presents the result from applying the tool on a sample of bicycle routes in Gothenburg and compares the results with analyses from previous models and with empirical data of bicycling along the same routes

Bilevel programming for analysis of low-complexity control of linear systems with constraints

In this paper we use bilevel programming to find the maximum difference between a reference controller and a low-complexity controller in terms of the infinity-norm difference of their control laws. A nominal MPC for linear systems with constraints, and a robust MPC for linear systems with bounded additive noise are considered as reference controllers. For possible low-complexity controllers we discuss partial enumeration (PE), Voronoi/closest point, triangulation, linear controller with saturation, and others. A small difference in the norm between a low-complexity controller and a robust MPC may be used to guarantee closed-loop stability of the low-complexity controller and indicate that the behaviour or performance of the low-complexity controller will be similar to that of the reference one. We further discuss how bilevel programming may be used for closed-loop analysis of model reduction

Barn og rom. Refleksjoner over barns opplevelse av rom

SINTEF Byggforsk og Dronning Mauds Minne Høgskole hadde på oppdrag fra Trondheim kommune undersøkt to barnehager bygd etter baseprinsipp med fokus på hvordan fysiske omgivelser danner premisser for, og rammer rundt, barns utfoldelse i barnehagen. Resultat fra prosjektet skal gi innspill til utvikling av nybygg, samt gi innspill til endring i de eksisterende barnehagene. Problemstillingene for forskning er todelt. Sentrale spørsmål i forskningsprosjektet er følgende: - Barnehagens steder og rom i et dannelsesperspektiv - Barnehagens fysiske utforming og Trondheim kommunes målsettinger i funksjons- og arealprogram for barnehager.publishedVersio

Sensor Network Architectures for Monitoring Underwater Pipelines

This paper develops and compares different sensor network architecture designs that can be used for monitoring underwater pipeline infrastructures. These architectures are underwater wired sensor networks, underwater acoustic wireless sensor networks, RF (Radio Frequency) wireless sensor networks, integrated wired/acoustic wireless sensor networks, and integrated wired/RF wireless sensor networks. The paper also discusses the reliability challenges and enhancement approaches for these network architectures. The reliability evaluation, characteristics, advantages, and disadvantages among these architectures are discussed and compared. Three reliability factors are used for the discussion and comparison: the network connectivity, the continuity of power supply for the network, and the physical network security. In addition, the paper also develops and evaluates a hierarchical sensor network framework for underwater pipeline monitoring

Geochemistry and petrology of palaeocene coals from Spitzbergen — Part 2: Maturity variations and implications for local and regional burial models

The Central Tertiary Basin is an uplifted part of the North Barents Shelf and should be an ideal location to understand the thermal history, maximum burial depth and overburden thickness in this petroleum-rich area. Efforts to quantify the thermal history of the region have been hampered by reports of hyper-thermal conditions, maturity gaps and maturity inversions in the Tertiary vitrinite reflectance (Ro) record. This has been attributed to thermal insulation effects, vitrinite reflectance due to bitumen impregnation and later Tertiary volcanism. Through the use of Ro, organic maturity parameters, 13C NMR and Rock–Eval pyrolysis, this study aims to explain the unusual maturity effects observed and the implications for burial models. Within single seams, Ro % ranges from 0.5 to 0.78 with increasingly bimodal distribution up-seam. Analysis of coal aromaticity and the results of Rock–Eval analysis confirm that maturity gaps and inversions only occur where the vitrinite reflectance has been suppressed by high bitumen content (300–400 mg/g coal). Samples with the lowest hydrogen index values (< 250 mg HC / TOC) provide the most accurate estimates of the vitrinite reflectance. Results indicate maximum burial temperatures of 120 °C in the basin centre and 100 °C at the basin margins with a hyper-thermal gradient of approximately 50 °C/km. This gradient implies a total overburden of 2 km of which 1 km has been lost. Maximum burial depth and total erosional sediment load to the Barents Shelf are therefore at the lower end of current estimates

Paleocene methane seep and wood-fall marine environments from Spitsbergen, Svalbard

A recently discovered Paleocene seep locality from Fossildalen on Spitsbergen, Svalbard, is described. This is one of a very few seep communities of the latest Cretaceous–earliest Palaeogene age, and the best preserved Paleocene seep community known so far. The seep carbonates and associated fossils have been first identified in museum collections, and subsequently sampled in the field. The carbonates are exclusively ex-situ and come from the offshore siltstones of the Basilika Formation. Isotopically light composition (δ13C values approaching -50‰ V-PDB), and characteristic petrographic textures of the carbonates combined with the isotopically light archaeal lipid are consistent with the formation at fossil hydrocarbon seep. The invertebrate fauna associated with the carbonates is of moderate diversity (16 species) and has a shallow water affinity. It contains a species of the thyasirid genus Conchocele, common in other seeps of that age. The finding sheds new light onto the history of seepage on Svalbard, and onto the evolution and ecology of seep faunas during the latest Cretaceous–earliest Palaeogene time interval