No description available.

No description available.

The rapid evolution of portable devices and social media has enabled pervasive forms of distributed cooperation. A group could perform a task using a heterogeneous set of the devices (desktop, mobile), connections (wireless, wired, 3G) and software clients. We call this form of systems Distributed Dynamic Cooperative Environments (DDCEs). Content in DDCEs is created and shared by the users. The content could be static (e.g., video or audio), dynamic (e.g.,wikis), and/or Objects with behavior. Objects with behavior are programmed objects that take advantage of the available computational services (e.g., cloud-based services). Providing a desired Quality of Experience (QoE) in DDCEs is a challenge for cooperative systems designers. DDCEs are expected to provide groups with the utmost flexibility in conducting their cooperative activities. More flexibility at the user side means less control and predictability of the groups' behavior at the system side. Due to the lack of Quality of Service (QoS) guarantees in DDCEs, groups may experience changes in the system behavior that are usually manifested as delays and inconsistencies in the shared state. We question the extent to which cooperation among group members is sensitive to system changes in DDCEs. We argue that a QoE definition for groups should account for cooperation emergence and sustainability. An experiment was conducted, where fifteen groups performed a loosely-coupled task that simulates social traps in a 3D virtual world. The groups were exposed to two forms of system delays. Exo-content delays are exogenous to the provided content (e.g., network delay). Endo-content delays are endogenous to the provided content (e.g., delay in processing time for Objects with behavior). Groups' performance in the experiment and their verbal communication have been recorded and analyzed. The results demonstrate the nonlinearity of groups' behavior when dealing with endo-content delays. System interventions are needed to maintain QoE even though that may increase the cost or the required resources. Systems are designed to be used rather than understood by users. When the system behavior changes, designers have two choices. The first is to expect the users to understand the system behavior and adjust their interaction accordingly. That did not happen in our experiment. Understanding the system behavior informed groups' behavior. It partially influenced how the groups succeeded or failed in accomplishing its goal. The second choice is to understand the semantics of the application and provide guarantees based on these semantics. Based on our results, we introduce the following design guidelines for QoE provision in DDCEs. • If possible the system should keep track of information about group goals and add guarding constraints to protect these goals. • QoE guarantees should be provided based on the semantics of the user-generated content that constitutes the group activity. • Users should be given the option to define the content that is sensitive to system changes (e.g., Objects with behavior that are sensitive to delays or require intensive computations) to avoid the negative impacts of endo-content delays. • Users should define the Objects with behavior that contribute to the shared state in order for the system to maintain the consistency of the shared state. • Endo-content delays were proven to have significantly negative impacts on the groups in our experiment compared to exo-content delays. We argue that system designers, if they have the choice, should trade processing time needed for Objects with behavior for exo-content delay. / Ph. D.

The goal of this Ph.D. research is to explore the IPD contractual strategies, to highlight the elements that distinguish IPD from a traditional delivery approach, to analyze how trust-based relationships are established and promoted, and to demonstrate if/how trust and IPD contractual principles correlate. The result of this research will promote the understanding of the industry on the strategies that promote trust and integration through real world case studies. The significance of the subject becomes more evident when reflecting on the current industry's crisis: productivity loss, fragmented delivery process, and lack of trust and collaboration. Through a literature review a Project Delivery and Contracting Strategies (PDCS) framework, an IPD traits framework, and a trust-Building framework are developed. The frameworks are used as the organizational tools to structure and inquire relevant information on the two IPD projects. An expert panel is assembled to discuss the frameworks and the findings of literature analysis and to seek the industry's insight on the units of analysis for contract, and the units of measure for trust. The units of analysis for contract are elements, such as strategies for risks/rewards sharing, liability considerations, decision making authority, and governance. The units of measure for trust are the individuals' perception, and the trust-building attributes as outlined in table 4-1. Two IPD projects were selected and their contract agreements were studied. A questionnaire including both open-ended questions and multiple choice questions was developed based on the information collected through: 1. the IPD agreements in each case study, 2. the literature-based frameworks on trust and project delivery contracting strategies. Accordingly, two IPD case studies are developed following the analysis of their IPD agreements and the individual one-on-one interviews with their key IPD players. The trust-building framework presented in this work includes a series of techniques that the contracting parties can follow when establishing their contractual and managerial strategies and also when interacting with each other. / Ph. D.

Wearable sensors and systems have become increasingly popular for diverse applications. An emerging technology for physical activity assessment is Smart Textile Systems (STSs), comprised of sensitive/actuating fiber, yarn, or fabric that can sense an external stimulus. All required components of an STS (sensors, electronics, energy supply, etc.) can be conveniently embedded into a garment, providing a fully textile-based system. Thus, STSs have clear potential utility for measuring health-relevant aspects of human activity, and to do so passively and continuously in diverse environments. For these reasons, STSs have received increasing interest in recent studies. Despite this, however, limited evidence exists to support the implementation of STSs during diverse applications. Our long-term goal was to assess the feasibility and accuracy of using an STS to monitor human activities. Our immediate objective was to investigate the accuracy of an STS in three representative applications with respect to occupational scenarios, healthcare, and activities of daily living. A particular STS was examined, consisting of a smart socks (SSs), using textile pressure sensors, and smart undershirt (SUS), using textile strain sensors. We also explored the relative merits of these two approaches, separately and in combination. Thus, five studies were completed to design and evaluate the usability of the smart undershirt, and investigate the accuracy of implementing an STS in the noted applications. Input from the SUS led to planar angle estimations with errors on the order of 1.3 and 9.4 degrees for the low-back and shoulder, respectively. Overall, individuals preferred wearing a smart textile system over an IMU system and indicated the former as superior in several aspects of usability. In particular, the short-sleeved T-shirt was the most preferred garments for an STS. Results also indicated that the smart shirt and smart socks, both individually and in combination, could detect occupational tasks, abnormal and normal gaits, and activities of daily living with greater than 97% accuracy. Based on our findings, we hope to facilitate future work that more effectively quantifies sedentary periods that may be deleterious to human health, as well as detect activity types that may be help or hinder health and fitness. Such information may be of use to individuals and workers, healthcare providers, and ergonomists. More specifically, further analyses from this investigation could provide strategies for: (a) modifying a sedentary lifestyle or work scenario to a more active one, and (b) helping to more accurately identify occupational injury risk factors associated with human movement. / PHD / The use of interactive or “smart” textiles that have sensing material(s) incorporated into them supports an emerging technology for physical activity assessment called Smart Textile Systems (STSs). STSs are an increasingly useful technology for researchers, athletes, patients, and others. Our aims in the current study were the development and assessment of a new smart undershirt (SUS) that was designed to monitor low-back and shoulder motions, and to evaluate the preferred placement and usability of two STSs. We also assessed the accuracy of two smart garments, smart socks (SSs) and the SUS, both individually and in combination. Accuracy was evaluated in terms of the ability of these systems to distinguish between diverse simulated occupational tasks, normal and abnormal walking patterns, and several typical daily activities. Our investigation indicated that STSs could discriminate between different human activities common in three domains: occupational scenarios, healthcare, and activities of daily life. We also found that both smart garments (i.e., SSs and SUS) provided similar accuracy for activity classification, typically exceeding 97%, and thus there was no clear superiority between these two smart garments. We conclude that, overall, smart garments represent a promising area of research and a potential alternative for discriminating and monitoring a range of human activities. Use of this technology in the future may have positive implications for health promotion.

Tallinjen är en visuell representation av talordningen som kan användas i undervisningen, där eleverna utmanas att förklara sina tankar. Denna studie utgår ifrån tidigare forskning, närmare bestämt en undersökning genomförd av Skoumpourdi (2010) i Grekland. Syftet med denna studie är att bidra med kunskap om hur användningen av tallinjen påverkar elevers förmåga att lösa problemlösningsuppgifter. Frågeställningarna som har besvarats är: Hur skiljer sig elevers förmåga att lösa problemlösningsuppgifter med och utan tallinje? På vilka olika sätt använder elever tallinjen i sina lösningar? Vilka kritiska aspekter identifieras i elevers lösningar av uppgifter med en tallinje? 124 elever i årskurs 2 fick svara på sex problemlösningsuppgifter där hälften av eleverna fick uppgifter när tallinjen fanns med och hälften fick utan tallinje. De skulle även visa hur de löste uppgifterna. Utifrån det insamlade materialet gjordes en kvantitativ analys där svaren sammanställdes i ett Excel dokument över rätt, fel och icke svar. Resultatet visar att elever löser problemlösningsuppgifter mer framgångsrikt när det finns en tallinje med. Denna studies resultat skiljer sig från Skoumpourdis (2010) studie som visade att eleverna lyckades bättre med problemlösningsuppgifterna när tallinjen inte fanns med. Studiens teoretiska utgångspunkt var variationsteorin. Det gjordes även en kvalitativ analys av hur elever som använde tallinjen löste två av uppgifterna. Utifrån denna analys identifierades kritiska aspekter. / The number line is a visual representation of the numerical order, which can be used for educational purposes, as it challenges students to explain their thought processes. This study is based on previous research/studies, particularly the study from Greece by Skoumpourdi (2010). The purpose of this study is to contribute to a further understanding of how to use the number line that effectively helps students solve problem-solving questions. The formulated questions that have been answered in this study are: What are the differences in students’ ability to solve problem-solving questions with and without the number line? In which ways do students incorporate the number line in their solutions? What critical aspects can be identified in the students’ solutions with the number line? 124 students in grade 2 answered six problem-solving questions in which half of the students were given the number line beside the questions and the other half without it. They would also provide an explanation for how they solved the questions. From the collected data, a quantitative method was used to compile the answers by the students in an Excel document, which was divided into the correct, wrong and no answer. The result showed that students solved problem-solving questions more successfully using the number line. This study’s result differs from the survey by Skoumpourdis (2010), which showed that students solved problem-solving questions more successfully without incorporating the number line. The study’s theoretical starting point was variation theory. A qualitative approach was also used to analyze how the students used the number line to solve two of the problems. Thereafter, an analysis was conducted of this to identify the critical aspects.

No description available.

Zahlreiche Studien belegen, dass Menschen Schwierigkeiten bei der simultanen Ausführung von 2 Aufgaben haben. Diese Schwierigkeiten sind durch zusätzliche Leistungskosten in Doppelaufgabensituationen im Vergleich zu Einzelaufgabensituationen gekennzeichnet (d.h. Doppelaufgabenkosten). Allerdings konnten jüngere Studien eine deutliche Reduktion der Doppelaufgabenkosten am Ende von Übung zeigen. Der Befund von Doppelaufgabenkosten am Beginn und die deutliche Reduktion davon am Ende der Übung indiziert, dass diese Reduktion durch spezifische Lernmechanismen geleistet wird. Obwohl sich frühere Studien bereits mit diesen Mechanismen befassen, bleiben die genauen Mechanismen der Reduktion der Doppelaufgabenkosten durch Übung unbekannt. Das Ziel von vier Studien der vorliegenden Arbeit ist die Spezifizierung dieser Mechanismen durch die Anwendung einer Doppelaufgabensituation mit einer visuellen und einer auditiven Teilaufgabe (Schumacher et al., 2001). Untersuchungen zu Lernmechanismen innerhalb der Teilaufgaben zielten auf die genaue Lokalisation von Verkürzungen der Verarbeitungszeit in diesen Aufgaben während der Übung. Erstmalig konnte ich zeigen, dass die Verkürzung der Aufgabenverarbeitung in Doppelaufgabensituationen vor allem durch eine verkürzte Antwortauswahlstufe erfolgt. Demgegenüber haben Untersuchungen zu Lernmechanismen zwischen den Teilaufgaben auf den Erwerb von Fertigkeiten der Aufgabenkoordination gezielt. Hier habe ich Nachweise erbracht, dass diese Fertigkeiten während der Übung von Doppelaufgaben erwerbbar sind, aber dass kein Erwerb während Einzelaufgabenübung erfolgt. Weiterhin habe ich gezeigt, dass diese Fertigkeiten in alternative Doppelaufgabensituationen transferierbar sind. Allerdings gibt es keinen Nachweis für den Fertigkeitstransfer in Aufgabenwechsel- und Attentional-Blink-Situationen. Um das Ergebnis von Lernmechanismen weiter zu spezifizieren, habe ich gezeigt, dass die Doppelaufgabenleistung in der visuellen aber nicht in der auditiven Teilaufgabe stabil ist nachdem die Übung beendet wurde. Die vorliegenden Befunde zu Lernmechanismen werden in ein Modell von geübter Doppelaufgabenleistung, das Latent Bottleneck Model, integriert und neue Annahmen im Rahmen dieses Modells diskutiert. / Numerous studies showed that people have difficulty performing two tasks at the same time. This difficulty is indicated by additional performance costs in dual-task situations when compared to single-task situations, i.e. dual-task costs. However, recent evidence has shown a substantial reduction of dual-task costs through practice. The finding of dual-task costs at the beginning and the reduction thereof at the end of practice indicates that this reduction must be accomplished via specific learning mechanisms. Although such mechanisms have been addressed in previous studies, the specific mechanisms contributing to practice related dual-task cost reduction remained unknown. The aim of four studies in the present work is to specify these mechanisms by applying a dual-task situation including a visual and an auditory component task (Schumacher et al., 2001). Investigations on learning mechanisms within the component tasks aimed to identify loci of stage shortening in these tasks through practice. For the first time I showed that component task processing in dual-task situations is mainly shortened through a shortening at the response selection stage. In contrast, investigations on learning mechanisms between the component tasks focussed on the acquisition of task coordination skills. Here I provided evidence that these skills are acquired during dual-task practice and there is no acquisition of these skills during single-task practice. Additionally, I demonstrated that these skills are transferable to alternative dual-task situations. There is, however, no evidence for transfer of these skills to task switching and attentional blink paradigms. In order to further specify the result of the learning mechanisms, I showed that dual-task performance in the visual but not in the auditory task is stable after practice has finished. The present findings on learning mechanisms are integrated into a model of practiced dual-task performance, the latent bottleneck model, and new assumptions in the framework of this model are discussed.

Werden zwei Aufgaben in einem Doppelaufgaben-Paradigma gleichzeitig bearbeitet, dann treten oft sogenannte Doppelaufgabenkosten auf (längere Reaktionszeiten und/oder höhere Fehlerzahlen). Diese Doppelaufgabenkosten werden durch einen zentralen “Flaschenhals” erklärt, der die gleichzeitige Verarbeitung der beiden Aufgaben an der zentralen Verarbeitungsstufe der Reaktionsauswahl verhindert. Das Ziel der vorliegenden Arbeit war es, einige mögliche Faktoren der Verarbeitungsreihenfolge an diesem Flaschenhals zu untersuchen. Die Studie zeigt, dass die Ankunftszeit am Flaschenhals ein wichtiger Faktor bei der Festlegung der Verarbeitungsreihenfolge ist. Zusätzlich ist der Einfluss der Ankunftszeit auf die Verarbeitungsreihenfolge unabhängig davon, welche der beiden Aufgaben manipuliert wurde um den Einfluss dieser Aufgabe zu untersuchen (visuelle oder auditorische Aufgabe). Ein zweiter Faktor der manipuliert wurde, ist die Instruktion an die Probanden. Die Ergebnisse zeigen, dass unter bestimmten Instruktionsbedingungen kognitive Kontrollprozesse aktiviert zu werden scheinen. Als dritten Faktor wurden Aufgabenanforderungen untersucht, indem eine Aufgabe mit zeitlicher Reihenfolge-Entscheidung mit einer Doppelaufgabe mit zufälliger Aufgabenreihenfolge, d.h.: Bestimmung der zeitlichen Reihenfolge mit der zusätzlichen Anforderung einer Reaktionswahl-Aufgabe, verglichen wurde. Die Ergebnisse dieser Experimente deuten darauf hin, dass die Entscheidung über die zeitliche Reihenfolge der beiden Aufgaben zwischen der Wahrnehmungsstufe und der Reaktionswahlstufe getroffen wird. / The simultaneous performance of two tasks in a dual-task paradigm is often accompanied by dual-task costs (longer reaction times and/or higher error rates). These dual-task costs have been explained by the existence of a central bottleneck which prohibits the simultaneous processing of the two tasks at the central response-selection stage of information processing. The aim of the present work was to investigate several of the possible factors which determine the task processing order at this central bottleneck. The study shows that the arrival time of the two tasks at the bottleneck plays an important role in the determination of task order. Additionally, the influence of the arrival time on processing order is independent of the component task which is manipulated to test the influence of that task (i.e., visual & auditory task). A second factor that was manipulated is the instruction given to the participants. The results show that cognitive control processes are activated under certain instruction conditions. As a third factor, task requirements were investigated by comparing a temporal order judgement task with a dual task with random task order (i.e., temporal order judgement with the additional requirement to do a choice-RT task). The results suggest that the decision about the temporal order of the two tasks is located between the perception stage and the response-selection stage of processing.

This dissertation provides an innovative mechanism to collaborate two geographically separated people on a physical task and a novel method to measure Complexity Index (CI) and calculate Minimal Complexity Index (MCI) of a collaboration protocol. The protocol is represented as a structure, and the information content of it is measured in bits to understand the complex nature of the protocol. Using the complexity metrics, one can analyze the performance of a collaborative system and a collaboration protocol. Security and privacy of the consumers are vital while seeking remote help; this dissertation also provides a novel authorization framework for dynamic access control of resources on an input-constrained appliance used for completing the physical task. Using the innovative Collaborative Appliance for REmote-help (CARE) and with the support of a remotely located expert, fifty-nine subjects with minimal or no prior mechanical knowledge are able to elevate a car for replacing a tire in an average time of six minutes and 53 seconds and with an average protocol complexity of 171.6 bits. Moreover, thirty subjects with minimal or no prior plumbing knowledge are able to change the cartridge of a faucet in an average time of ten minutes and with an average protocol complexity of 250.6 bits. Our experiments and results show that one can use the developed mechanism and methods for expanding the protocols for a variety of home, vehicle, and appliance repairs and installations.