Search results for "construct"

Effect of two novel bio-based rejuvenators on the performance of 50% RAP mixes - a statistical study on the complex modulus of asphalt binders and as…

2019

An experimental study was conducted to evaluate the effectiveness of two bio-additives as rejuvenators on the properties of asphalt mixtures containing 50% RAP and their binder constituents containing 37% RAP binder. Before mixing, the rejuvenators were blended with fresh bitumen and the extracted and recovered RAP bitumen, and changes in the rheological properties of the binders were assessed using performance grading (PG) criteria. The results showed that both rejuvenators could improve the low-temperature performance of the aged RAP binder and restore its low-temperature properties. Master curves for the unaged, RTFO-aged, and PAV aged blends were constructed using both the Christensen-A…

Drivers of peat accumulation rate in a raised bog: impact of drainage, climate, and local vegetation composition

2017

We used variation partitioning to assess the relative importance of drainage, climate and local vegetation composition for the development of a raised bog. As a case study we selected Teici (Teici) Bog in Latvia (north-east Europe). Explanatory variables together explained 74 % of the variation in peat accumulation and only the residue of 26 % remained unexplained. Our study showed that the local vegetation composition and dominant Sphagnum species significantly influence peat accumulation rates. The results of linear models revealed that, under natural conditions, minor drainage and even strong drainage of the peat is associated with a positive growth balance of the system. However, draina…

Data Compression Approach for Long-Term Monitoring of Pavement Structures

2019

Pavement structures are designed to withstand continuous damage during their design life. Damage starts as soon as the pavement is open to traffic and increases with time. If maintenance activities are not considered in the initial design or considered but not applied during the service life, damage will grow to a point where rehabilitation may be the only and most expensive option left. In order to monitor the evolution of damage and its severity in pavement structures, a novel data compression approach based on cumulative measurements from a piezoelectric sensor is presented in this paper. Specifically, the piezoelectric sensor uses a thin film of polyvinylidene fluoride to sense the ener…

Construct validity of the LSB-50 in argentinean adults: cross-validation and factorial invariance

2015

El trabajo se propone aportar evidencias de validez referidas al Listado de Síntomas Breve (LSB-50; de Rivera y Abuín, 2012), instrumento psicométrico de screening para medir síntomas sicológicos, analizadas en una muestra de adultos argentinos. Los participantes fueron 1291 individuos distribuidos proporcionalmente según sexo (51% mujeres; 49% varones) con edades entre 18 y 89 años (M = 38.9, DE = 16.49). Se llevaron a cabo estudios de validación cruzada e invarianza factorial para examinar si un modelo de siete factores que se correspondía con siete escalas clínicas (Hipersensibilidad, ObsesionesCompulsiones, Ansiedad, Hostilidad, Somatización, Depresión, y Alteraciones del sueño) present…

Pollutant Emissions in Ports: A Comprehensive Review

2021

In recent decades, maritime transport demand has increased along with world population and global trades. This is associated with higher pollution levels, including the emissions of GHG and other polluting gases. Ports are important elements within maritime transport and contribute themselves to pollutant emissions. This paper aims to offer a comprehensive yet technical review of the latest related technologies, explaining and covering aspects that link ports with emissions, i.e., analyzing, monitoring, assessing, and mitigating emissions in ports. This has been achieved through a robust scientific analysis of very recent and significant research studies, to offer an up-to-date and reliable…

Explaining Individual and Collective Programming Students’ Behavior by Interpreting a Black-Box Predictive Model

2021

Predicting student performance as early as possible and analysing to which extent initial student behaviour could lead to failure or success is critical in introductory programming (CS1) courses, for allowing prompt intervention in a move towards alleviating their high failure rate. However, in CS1 performance prediction, there is a serious lack of studies that interpret the predictive model’s decisions. In this sense, we designed a long-term study using very fine-grained log-data of 2056 students, collected from the first two weeks of CS1 courses. We extract features that measure how students deal with deadlines, how they fix errors, how much time they spend programming, and so forth. Subs…

NANOTECHNOLOGY IN CONSTRUCTION

2011

An Information Systems Design Product Theory for Software Project Estimation and Measurement Systems

2009

There is relatively little research on software Project Estimation and Measurement Systems (PEMS). Commercial PEMS vary in functionality and effective- ness. Their intended users thus do not know what to ex- pect from PEMS and how to evaluate them. This paper creates an information system design product theory for the class of PEMS that prescribes the meta-requirements, the meta-design, and applicable theories for all products within the class. Meta-requirements and the meta-design are derived from the project estimation and measurement literature, experiences obtained during more than ten years of empirical work in Finnish Software Measurement Association, and a commercially available PEMS.

Relationships among Bicycle Rider Behaviours, Anger, Aggression, and Crashes in Finland

2022

Riding a bicycle is increasingly encouraged as a sustainable transport solution, especially in urban areas. However, safety concerns, both perceived and actual, can significantly lower the willingness to ride among the population. To support cycling planning and policy in the double task of increasing the levels of cycling while mitigating crash risk, there is a need to better understand the behaviours and attitudes of bicycle riders. In this manuscript, we study a cohort of Finnish bicycle riders through four questionnaires, the Cycling Behaviour Questionnaire (CBQ), Cyclist Risk Perception and Regulation Scale (RPRS), Cyclist Anger Scale (CAS), and Cyclist Aggression Expression Inventory …

Concrete arch bridges built by lattice cantilevers

2013

In this paper a study about concrete arch bridges built by lattice cantilevers is presented. Lattice cantilevers are partial structures composed of deck, arch, piers and provisional steel diagonals, organized as reticular cantilever girders, in order to build arch bridges without the use of centrings, supports or temporary towers. Characteristics of this construction methodology with its variants are explained together with their implications in the erection sequence. Partial elastic scheme method is implemented in order to find initial forces of temporary cables and a forward analysis is carried out to follow the actual sequence of construction, by extending a procedure already applied to …