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An ergonomic driver workspace and interface design is essential to ensure a healthier and comfortable driving experience in terms of driver perceptions, postures, and interface pressures. Developing more effective methods for driver-side interior design and evaluation, hence, requires thorough investigation of: 1) which perceptual responses are more relevant to ensuring ergonomic quality of a design, 2) the interrelationships among perceptual responses and objective measures, and 3) whether current assumptions regarding driver behaviors, and tools for specifying these behaviors, are valid for the design and evaluation. Existing studies, however, have rarely addressed these topics comprehensively, and often have been conducted with unsubstantiated assumptions. In contrast, this work sought to address these topics in a way that jointly considers characteristics of driver perceptions, behaviors, and objective measures to develop an improved design and evaluation methodology for driver workspace and interface, and that can also investigate the validity of implicit assumptions regarding perceptual relevance and drivers' behaviors. The first part of this work investigated drivers' perceptions in relation to driver workspace design and evaluation. Specifically, it examined the efficacy of several perceptual ratings, when used for evaluating automobile interface design. Results showed that comfort ratings were more effective at distinguishing among interface designs, in contrast to the current common practice of using discomfort ratings for designing and evaluating interface designs. Two distinct decision processes to relate local to global perceptions were also identified (i.e., global comfort as an average of local comforts, and global discomfort predominantly influenced by maximal local discomforts). These findings were observed consistently across age and cultural groups. In addition, this work provided empirical support for an earlier hypothetical comfort/discomfort model, which posited comfort and discomfort are complementary, yet independent entities. In order to facilitate the integration of driver perceptions and dynamic behaviors into driver workspace design and evaluation, the second part of this work clarified the relationships between perceptual ratings and various types of driver-seat interface pressure. Interface pressure was found to be more strongly related to overall and comfort ratings than to discomfort ratings, which is also in marked contrast with existing work that has focused on identifying association between discomfort and interface pressure. Specific pressure interface requirements for comfortable driver workspace design and evaluation were also provided. Lastly, this work specified more rigorous driving postures for digital human models (DHMs), based on actual drivers' perceptions, postural sensitivity, and static behavioral characteristics, to facilitate proactive design and evaluation that enables cost/time efficient vehicle development. Drivers' behavioral characteristics observed in this work were applied to the driver workspace design. First, postural sensitivity obtained by using a psychophysics concept has been applied to determination of core seat track ranges. Second, postural data have been used: 1) to review relevant industry standards on driver accommodation, 2) to investigate whether driving postures are bilaterally asymmetric, 3) to provide comfortable joint ranges, and lastly 4) to identify drivers' postural strategies for interacting with a vehicle. Overall, this work identified three important behavioral characteristics, specifically a bilateral imbalance in terms of interface pressure, bilaterally asymmetric joint posture, and postural strategies identified by cluster analysis. Such characteristics can be embedded in DHMs to describe more accurately actual driver behaviors inside a driver workspace, which is deemed to be a fundamental step to improved virtual ergonomic vehicle design and evaluation. In addition, the strategy-based classification method used in this work can be extended to simulate and predict more complex human motions. Practical and fundamental findings of this work will facilitate efficient and proactive design and evaluation of driver workspace and interface, and will help provide a healthier driving experience for a broader range of individuals. / Ph. D.

It has been found that traveling on the roadways at night is an inherently more dangerous task than driving during the daylight hours. Driving is primarily a visual task, and there are certain situations at night in which vision and safety may be compromised. The effects of glare produced by the headlamps of oncoming vehicles have become an interesting problem to many lighting researchers. Depending upon the opposing lighting design (beam distribution and intensity) and the lighting conditions inside the vehicle, oncoming headlamps can be both visually discomforting and disabling to drivers at night. In recent years, the newer High Intensity Discharge (HID) headlamps have raised some concern because of their increased light output and brighter appearance as opposed to traditional Halogen headlamps. The objective of this study was to evaluate the discomfort and disability glare produced by different oncoming headlamps under two driver light adaptation levels. This study took place on the Smart Road at the Virginia Tech Transportation Institute. During the Discomfort Glare portion, participants drove an experimental vehicle at 20mph past the oncoming headlamps and were asked to rate their overall discomfort with the subjective deBoer scale. The Disability Glare portion involved drivers detecting a static pedestrian in the roadway while approaching each different set of glare headlamps. It was hypothesized that there would be significant differences in detection distance and discomfort glare rating across the different glare headlamp and adaptation level combinations. It was also hypothesized that age would have a significant effect on detection distance, and the subjective ratings. The results of this study revealed many significant main effects and interactions for the discomfort and disability glare portions. The main effect of glare source was the only significant factor for discomfort glare. The main effects of age, glare source and pedestrian location were all significant for the disability portion. In addition, the interaction of pedestrian location and glare source was also significant. Overall, there was no clear relationship between subjective discomfort ratings and objective disability measures. The conclusions of this research will be valuable to the consumer as well as the manufacturers and designers of future headlamps in revealing how glare can affect drivers on the road at night. This information can help guide new designs to maximize forward visibility while minimizing glare. / Master of Science

This research was designed to investigate the relationship between Trait-based Individual differences (neuroticism and extraversion) and glare subjective responses as well as the actual contrast sensitivity when exposed to the same manipulated glare condition. In addition, the relationship between the glare subjective responses and actual contrast sensitivity was investigated. To examine the trait-based individual differences, the International Personality Item Pool (IPIP) was used while the subjective glare experience was examined utilizing modified glare discomfort rating scale. The visual performance was measured through the contrast sensitivity level using adjustable contrast level of the Landolt's C target. This investigation compared 36 individuals (9 high neuroticism scorers, 9 low neuroticism scorers, 9 high extraversion scorers, and 9 low extraversion scorers) on subjective discomfort glare rating responses and visual contrast sensitivity. The study is directed toward improving our understanding of influencing factors on the experience of discomfort glare, which may eventually be applied to the design of glare measurement methods, and toward training and selection of drivers and workers who may work under conditions of glare. Results indicated significant effect of extraversion trait on rating response while insignificant effect on visual related performance was found. The relationships between rating response and visual performance were also found to be quite low in this study. In conclusion, the expected model was supported but only on the extraversion trait. / Master of Science

Yes / The misery index (the unweighted sum of unemployment and inflation rates) was probably the first attempt to develop a single statistic to measure the level of a population’s economic malaise. In this letter, we develop a dynamic approach to decompose the misery index using two basic relations of modern macroeconomics: the expectations-augmented Phillips curve and Okun’s law. Our reformulation of the misery index is closer in spirit to Okun’s idea. However, we are able to offer an improved version of the index, mainly based on output and unemployment. Specifically, this new Okun’s index measures the level of economic discomfort as a function of three key factors: (1) the misery index in the previous period; (2) the output gap in growth rate terms; and (3) cyclical unemployment. This dynamic approach differs substantially from the standard one utilised to develop the misery index, and allow us to obtain an index with five main interesting features: (1) it focuses on output, unemployment and inflation; (2) it considers only objective variables; (3) it allows a distinction between short-run and long-run phenomena; (4) it places more importance on output and unemployment rather than inflation; and (5) it weights recessions more than expansions.

Of the studies that considered negatively sloped keyboards, results showed improved comfort and postural effects while typing on keyboards; however, few studies of negatively sloped keyboard angles and their resulting effects on objective physiological measures, psychological measures, and performance have been performed. The objective of this study was to quantify the effects of negative keyboard slopes on forearm muscle activity, wrist posture, key strike force, perceived discomfort, and performance to identify a negative keyboard angle or range of keyboard angles that minimizes exposure to hypothesized risk factors for hand/wrist work related musculoskeletal disorders. Ten experienced typists (4 males and 6 females) participated in a laboratory study to compare keyboard slopes ranging from 7° to -30°, at 10° increments from 0° to -30°, using an experimental wedge designed for use with QWERTY keyboards. Repeatability was examined by requiring participants to complete the experiment in two test sessions one week apart. Dependent variable data was collected during 10 minute test sessions. Wrist posture data revealed postural benefits for negative angles of 0° or greater compared to 7°. Specifically, the percentage of wrist movements within a neutral zone and percentage of wrist movements within ±5° and ±10° degrees increased as keyboard angle became more negative. EMG results were mixed with some variables supporting negative keyboard angles, while other results favored the standard keyboard configuration. Net typing speed supported the -10° keyboard angle, while other negative typing angles were comparable, if not better, than the standard. These findings showed that there was strong support for improved postural changes associated with negatively sloped keyboard wedges, though user perceptions favored the standard configuration. / Master of Science

Yes / Energy consumers oftentimes suffer some element of discomfort associated with the implementation of demand response programs as they aim to follow a suggested energy consumption profile generated from scheduling algorithms for the purpose of optimizing grid performance. This is because people naturally do not like to be told what to do or when to use their appliances. Although advances in renewable energy have made the consumer to also become energy supplier, who can actively cash in at times of the day when energy cost is high to either sell excess energy generated or consume it internally if required, thereby nullifying the adverse effect of this discomfort. But a majority of consumers still rely wholly on the supply from the grid. This impact on users' comfort who are active participants in demand response programs was investigated and ways to minimizing load scheduling discomfort was sought in order to encourage user participation.

Background and aims: Despite living with a gluten-free diet (GFD) Swedish women with coeliac disease (CD) report a lower level of well-being than women without the disease and men with the disease. The all-embracing aim of the thesis was to study experiences of living with coeliac disease in remission and to discover whether a patient education intervention can influence the perceived health and daily life of women with coeliac disease. Methods: Studies I-IV were based on the same sample, a total population of 106 women, > 20 years old, with confirmed CD, who had been treated with a GFD for a minimum of five years. From the total population of 106, 15 and 14 purposefully selected women were included in studies I and IV respectively, which had a phenomenological approach by which data was collected through recorded personal narrative interviews. The participants in studies II & III, comprising the total sample of 106 women, were randomized to one of two groups: either to the intervention group (n=54) that underwent a ten-session patient education (PE) program with problem based learning (PBL), or to a control group (n=52) that received information regarding CD, which was sent to their home on a regular basis. Data was collected by self-administered questionnaires. Study V included 22 purposefully selected people (11 women and 11 men) with confirmed CD that had experienced any kind of residual discomfort despite treatment for at least five years with a GFD. Data was collected by recorded semistructured interviews. Well-being (II-III) was assessed at baseline and after 10 weeks in all patients and after six months in the intervention group using the Psychological General Well-Being index and the Gastrointestinal Symptom Rating Scale. The interviews (I & IV), which were carried out before the start of the PE (I) and within two weeks of completion of the PE program and about three months after the first interview (IV), were analysed with descriptive phenomenology. The data from study V was analysed by content analysis. Results: In the results, the experience of living with CD in remission was described by participants as a constant quest for a normal life (I, V). Three constituents representing conditions necessary to achieve a normalised lifeworld were described (I) as: being secure, being in control, and being seen and included. The balance of thoughts in relation to these constituents proved to be crucial for the individual woman’s ability to experience a normal life, despite the disease. Participants described (V) conditions facilitating the opportunities to live a normal life, but also various barriers to reaching this goal. The results from the PE based on PBL (II-III) showed that the PE improved psychological well-being (II) and GI (III) in women with CD to some extent, but not sufficiently as the improvement reached normative values for women only at 10 weeks regarding PGWB mean total index, and at no point in time regarding GSRS mean total index. The effect had waned at the follow-up six months after the intervention was completed as regards the women’s psychological well-being. In coping with CD, it seems essential for women to interact with others with the same disease (IV). The interaction made women feel individually strengthened, and provided them with a broader perspective on life with CD. As a result, this strengthened their sense of self in relation to the disease. Knowledge given by other participants and experts could result in both relief and anxiety. The results from the PE based on PBL (II-III) showed that the PE improved psychological well-being (II) and GI (III) in women with CD to some extent, but not sufficiently as the improvement reached normative values for women only at 10 weeks regarding PGWB mean total index, and at no point in time regarding GSRS mean total index. The effect had waned at the follow-up six months after the intervention was completed as regards the women’s psychological well-being. In coping with CD, it seems essential for women to interact with others with the same disease (IV). The interaction made women feel individually strengthened, and provided them with a broader perspective on life with CD. As a result, this strengthened their sense of self in relation to the disease. Knowledge given by other participants and experts could result in both relief and anxiety.