Assessment of Fitts' Law for Quantifying Combined Rotational and Translational Movements

Objective: To develop a model for human performance in combined translational and rotational movements based on Fitts' law. Background: Fitts' law has been successfully applied to translational movements in the past, providing generalization beyond a specific task as well as performance predictions. For movements involving both translations and rotations, no equivalent theory exists, making comparisons of input devices for these movements more ambiguous. Method: The study consisted of three experiments. In the first two, participants performed either pure translational or pure rotational movements of 1 degree of freedom. The third experiment involved the same movements combined. Results: On average, the performance times for combined movements were equal to the sum of the times for equivalent separate rotational and translational movements. A simple Fitts' law equivalent for combined movements with a similar slope as the separate components was proposed. In addition, a significant degree of coordination of the combined movements was found. This had a strong bias toward a parallel execution in 12 out of 13 participants. Conclusion: Combined movements with rotations and translations of 1 degree of freedom can be approximated using a simple Fitts' law equivalent. The rotational and translational components appear to be coordinated by the central nervous system to generate a parallel execution. Application: The results may help drive human interface designs and provide insights into the coordination of combined movements. Future extensions may be possible for the movements of higher degrees of freedom used in robot teleoperation and virtual reality applications.This work was supported by the Institute for Dexterous Space Robotics (Grant No. NNX06AD23G).Publicad

The association between self-injurious behaviors and autism spectrum disorders

A key area of concern in children with autism spectrum disorders (ASDs) are self-injurious behaviors (SIBs). These are behaviors that an individual engages in that may cause physical harm, such as head banging, or self-biting. SIBs are more common in children with ASD than those who are typically developing or have other neurodevelopmental disabilities. Therefore, it is important that clinicians who work with children with ASD have a solid understanding of SIB. The purpose of this paper is to review the research on the epidemiology of SIB in children with ASD, factors that predict the presence of SIB in this population, and the empirically supported behavioral treatments available

Task-oriented kinematic design of a symmetric assistive climbing robot

ASIBOT is an assistive climbing robot that is capable of aiding in daily tasks from fixed docking stations in the environment. A task-oriented design process was applied to improve the robot kinematic structure, which was based on the grid method. Twelve different robot designs were optimized for typical kitchen scenarios, followed by a quantitative comparison

Identification of Carriers of Babesia microti From Local Populations of Borrelia-infested Ticks

Babesia microti is the causative agent for babesiosis, a blood-based parasitic disease that causes malaria-like symptoms in humans. It is passed through Ixodes scapularis (deer ticks) and is rising in incidence in the upper Midwest. Ticks that carry Borrelia, the causative agent for Lyme disease, may also carry Babesia microti. There are two major goals in this project: determine the prevalence of Babesia microti in ticks in the Winona area and determine whether those ticks that carry Borrelia are more likely to carry Babesia microti. The first part of the project requires development of a PCR assay that works well in detecting B. microti DNA. The second part involves development of a quantitative PCR (QPCR) assay that is more sensitive than regular PCR in order to detect B. microti DNA. DNA isolated from ticks by Dr. Kim Bates and others in her laboratory will be tested for the presence of B. microti. An update will be presented on progress in the project

Optimization Models and Algorithms for the Natural Gas Supply Chain

Sammendrag Denne PhD-avhandlinga består av sju artikler om operasjonsanalytiske modeller og algorit- mer for forsyningskjeden for naturgass. Fokus er på oppstrømsdelen av forsyningskjeden, fra produksjon til salg i markeder eller kontrakter. Artikkel I introduserer modellering av den rørbaserte forsyningskjeden, inkludert både fysiske og kommersielle perspektiver. Artikkel II presenterer en taktisk modell for en produsent/skiper i den rørbaserte forsyningskjeden. Gjennom tester på både syntetiske og realistiske datasett vises tilleggsverdien ved å hensynta markedsusikkerhet og ved å ha et forsyningskjedeperspektiv i slike modeller. Artikkel III presenterer en taktisk modell for forsyningskjeden for flytende natur- gass (LNG). Modellen er en utvidelse av det klassiske ‘lagerstyrte rutingproblemet’ (‘inventory routing problemet’, IRP). Artikkelen illustrerer den potensielle gevinsten ved å inkludere mer fleksibilitet enn hva som har vært industriens praksis, ved å tillate ikke-fulle skipslaster, å tillate flere ventedager i planene samt å integrere handel i planleggingen. Artikkel IV omhandler også LNG forsyningskjeden og presenterer en strategisk modell som gir anbefalinger om investering og avhending av LNG terminaler, skip og langsiktige kontrakter. To små eksempler brukes for å illustrere den forventede gevinsten av å ta et porteføljeperspektiv og å adressere prisusikkerhet ved hjelp av stokastisk programmering. Artikkel V presenterer et rammeverk med flere optimeringsmodeller designet for å evaluere bruken av avbrytbare transporttjenester i markedet for rørtransport. Resultatene fra en case-studie viser betydelig forbedret nettverksutnyttelse når avbrytbare transporttjenester supplerer garanterte transporttjenester i situasjoner hvor utfall og andre hendelser som reduserer kapasiteten kan inntreffe. De to siste artiklene presenterer algoritmer. Artikkel VI omhandler en ‘lås-og-løs-opp’ (‘fix- and-relax’) heuristikk for IRP’en presentert i Artikkel III. Numeriske resultater viser at heuris- tikken reduserer løsningstiden betydelig sammenlignet med å løse hele problemet med en generell blandet-heltallsløser, men den oppnår samtidig en noe dårligere målfunksjonsverdi. Artikkel VII presenterer en algoritme som løser matematiske program med likevektsbeskrankninger og heltallskrav (‘discretely-constrained mathematical program with equilibrium constraints’, DC-MPEC). Algoritmen bevises å konvergere til den optimale verdien. Artikkelen inneholder også et eksempel på en anvendelse i naturgassindustrien. Numeriske resultater viser at algoritmen gir en reduksjon i løsningstid relativt til den heuristiske motparten som har blitt publisert tidligere.Summary This PhD-thesis presents seven papers on operations research models and algorithms for the natural gas supply chain, focusing on the upstream part of the supply chain, from production to sale in markets or contracts. Paper I gives an introduction to modeling of the pipeline-based supply chain, including both physical and commercial perspectives. Paper II presents a tactical planning model for a pro- ducer/shipper in the pipeline supply chain. Tests on both synthetical and realistic datasets show the added value of addressing market uncertainty and taking a supply chain perspective in such models. Paper III presents a tactical model for the liquefied natural gas (LNG) supply chain, an extension of the classical inventory routing problem (IRP). The paper illustrates the potential gain from adding more flexibility than common business practice, by allowing partially loading/unloading of vessels, allowing more waiting days in the schedules and integrating mar- ket trade in the planning. Paper IV also treats the LNG supply chain, presenting a strategic model that recommends investment and disinvestment decisions in LNG terminals, vessels and long-term contracts. Two small examples are used to illustrate the expected gain from using a portfolio perspective and addressing price uncertainty through stochastic programming. Paper V presents a framework of multiple optimization models to evaluate the use of interruptible transportation services in the market for transportation capacity by pipeline. In a case study results show substantial improved network utilization with interruptible services as a supplement to firm services when outages and other capacity-reducing events might happen. The two last papers present algorithms. Paper VI treats a fix-and-relax heuristic for the IRP presented in Paper III. Numerical results show that the heuristic reduces solution times consid- erably compared to solving the whole problem in a general mixed integer solver, at the cost of slightly worse objective function values. Paper VII presents an algorithm to solve discretely- constrained mathematical programs with equilibrium constraints, including a proof of conver- gence to optimality and an example application in the natural gas industry. Numerical results show reduced solution times relative to the previously published heuristic counterpart of the algorithm.PhD i industriell økonomi og teknologiledelsePhD in Industrial Economics and Technology Managemen

Reindeer faeces and burning alleviates allelopathic effects of Empetrum humus on local plants

Empetrum hermaphroditum is one of the dominant species in many reindeer summer grazing areas in Northern Norway, forming unproductive, late successional stable vegetation covers. As studies of amount, and effect of, plant secondary metabolites emerging from E. hermaphroditum indicates strong inhibitory effect on other organisms, it is considered an invasive and allelopathic species. To investigate the effect of two potential ecological disturbances that can cause switch in vegetation cover from unproductive Empetrum domination to a more productive herbaceous plant dominated ecosystem, we compared soil pH and growth of Avenella flexuosa and Solidago virgaurea in heat treated, reindeer faeces fertilized and untreated humus obtained from E. hermaphroditum dominated areas. Measures of total plant biomass differed significantly both between treatments and between species, with all treatments having significantly different effects. Largest level of plant dry weight and pH was measured in fertilized humus, medium level in burned humus and the lowest level where obtained in untreated humus. Results indicate that heat treatment and addition of fertilizer to Empetrum humus improved growing conditions, by elevating pH or nutrient levels and likely omitting allelopathic effects of E. hermaphroditum

A comparison of feeding and mealtime problems in intellectually disabled adults with and without autism

Due to the dearth of information categorically describing feeding behaviors in those with autism spectrum disorders, the goal of this research is to examine the nature of feeding difficulties in adults with intellectual disabilities (ID) and Autism Spectrum Disorders (ASD). Feeding and mealtime behavior problems are an area of concern due to their impact on an individual’s daily functioning, as well as the potential for causing severe medical conditions (e.g., poor nutrition, choking, aspiration) that may ultimately lead to death. Due to the importance of this topic for proper diagnosis and treatment planning, a better understanding of these behaviors in persons with autism is imperative. Participants comprised one of two groups: ASD and ID (autism or Pervasive Developmental Disorders – Not Otherwise Specified) or ID and no additional Axis I diagnosis other than Pica or Rumination. The aim of the proposed study is to assess whether there are differences in aberrant eating habits between groups through the administration of the Screening Tool for fEeding Problems (STEP). Taking into account any medical conditions that may be underlying feeding problems, descriptive analyses and a MANOVA were used to analyze data. Results indicated that individuals with ASD and ID evinced more refusal related feeding problems whereas those with ID only had more feeding skill difficulties. Implications of these data are discussed

CDH11 Expression is Associated with Survival in Patients with Osteosarcoma

Previous studies have shown that cadherin-11 (CDH11) may be involved in the metastatic process of osteosarcoma. The correlation of the expression levels of CDH11 in osteosarcoma samples with the risk of disease progression and metastasis was examined. Real time qRT-PCR was used to quantify CDH11 expression in a set of newly established osteosarcoma cell lines, 11 primaries and five metastases, compared to the levels in 12 normal osteoblast cell lines established from healthy bone, and also in a set of 10 snap-frozen osteosarcoma samples. In all cases long term clinical follow-up data was available. The CDH11 expression level decreased gradually from the osteoblast to the primary cell lines (p=0.2184) and further to those established from the tumor metastases (p=0.0275). Importantly, the level of CDH11 expression correlated significantly (p=0.01) with patient survival (Kaplan-Meier survival analysis) in both sample sets (p=0.0128 for the cell lines, p=0.0492 for the biopsies). In conclusion, the results indicate that CDH11 may be useful as a prognostic marker of disease progression and survival in osteosarcoma

The emergence of challenging behaviors in at-risk toddlers with and without Autism Spectrum Disorder: a cross-sectional and risk factor study

Challenging behaviors including aggression, property destruction, stereotypy, and self injury occur at a high prevalence in individuals with Autism Spectrum Disorders (ASD). These behaviors are pervasive and chronic. Despite an increased probability and negative consequences, one area which has received little attention is the presence of challenging behaviors in infants and toddlers with ASD. Furthermore, there is a dearth of information identifying early age trends in the emergence of challenging behaviors and associated risk factors. The purpose of this investigation was to utilize a validated measure, the Baby and Infant Screen for Children with aUtIsm Traits - Part 3, to investigate the relationship of challenging behaviors to ASD in the very young child. In Study 1, it was demonstrated that infants and toddlers with ASD do evince more severe behavior symptoms than atypically developing non-ASD toddlers. A general increasing trend of severity of challenging behavior in infants and toddlers with ASD was noted to occur across age cohorts. Study 2 further investigated this relation in detail for the ASD group, where it was determined that there was a cluster of personal characteristics which appear to increase the risk of the young child with ASD engaging in higher rates of problem behavior. Risk factors which were found to be the most salient predictors of severe challenging behaviors included symptoms of comorbid mental illness (e.g., tantrums, conduct problems, anxiety, avoidance, inattention, and impulsivity), more severe autistic symptoms, and areas of developmental functioning. Implications of the results and directions for future research are discussed

Examining the Value of Literary Conversations: A critical mapping review of research into literary conversations in Scandinavian L1 classrooms

In recent years, researchers and practitioners in the field of Scandinavian L1 literature education have devoted considerable attention to literary conversations. In the Scandinavian countries, research into literature education has traditionally been characterized by qualitative studies. These tend to be published in various genres and are often written in a local language. This publishing pattern makes it challenging to obtain an overview of the field and its subfields. Hence there is an obvious need for a systematic review to map out the landscape of existing research into literary conversations. To that end, the present study investigates the characteristics of qualitative research into literary conversations in the Scandinavian L1 school subject with regard to key research approaches used, to the characteristics of the conversations studied, and to the pedagogical value ascribed to literary conversations. The findings show a joint belief in the value of literary conversations as a community for students’ learning in Scandinavian research. Multiple pedagogical gains are accounted for, both from the collaboration within the community itself and as a result of such collective work. In addition, the wide range of theoretical and methodological approaches mapped out from the studies investigated reveal some interesting challenges and also possible gains if further research is conducted.publishedVersio