The purpose of this study has been to explore how home care workers experience the use of ICT (that is, digital systems for time registration) in their work. The data collection took place through qualitative semi-structured interviews of seven home care employees in two different Swedish municipalities in Stockholm. Furthermore, a thematic analysis was performed by transcribing the interviews and trying to find common patterns or themes. The interviewees statements have been analyzed using two different theories: the role theory and Davies' (1994) theory of clock time and process time. The results show that the home care staff experience that the use of ICT leads to time pressure and stress during the working day. It also appears that the home care staff may experience the time registration system as a control function or monitoring method on them and their work. Other interviewees, on the other hand, describes that the registration of time contributes to increased security for both home care staff and the elderly care recipient. Finally, the results show that ICT is considered to contribute to an efficient and flexible home service work.

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Yes / A confocal microscope provides a sequence of images, at incremental depths, of the various corneal layers and structures. From these, medical practioners can extract clinical information on the state of health of the patient's cornea. In this work we are addressing problems associated with capturing and processing these images including blurring, non-uniform illumination and noise, as well as the displacement of images laterally and in the anterior posterior direction caused by subject movement. The latter may cause some of the captured images to be out of sequence in terms of depth. In this paper we introduce automated algorithms for classification, reordering, registration and segmentation to solve these problems. The successful implementation of these algorithms could open the door for another interesting development, which is the 3D modelling of these sequences.

Yes / Optimization plays a pivotal role in computer graphics and vision. Learning-based optimization algorithms have emerged as a powerful optimization technique for solving problems with robustness and accuracy because it learns gradients from data without calculating the Jacobian and Hessian matrices. The key aspect of the algorithms is the least-squares method, which formulates a general parametrized model of unconstrained optimizations and makes a residual vector approach to zeros to approximate a solution. The method may suffer from undesirable local optima for many applications, especially for point cloud registration, where each element of transformation vectors has a different impact on registration. In this paper, Reweighted Discriminative Optimization (RDO) method is proposed. By assigning different weights to components of the parameter vector, RDO explores the impact of each component and the asymmetrical contributions of the components on fitting results. The weights of parameter vectors are adjusted according to the characteristics of the mean square error of fitting results over the parameter vector space at per iteration. Theoretical analysis for the convergence of RDO is provided, and the benefits of RDO are demonstrated with tasks of 3D point cloud registrations and multi-views stitching. The experimental results show that RDO outperforms state-of-the-art registration methods in terms of accuracy and robustness to perturbations and achieves further improvement than non-weighting learning-based optimization.

This dissertation consists of two essays. The first provides evidence that the recent revival of shelf equity offers is related to changes in how firms use shelf registration. During 1990-2003 firms that make shelf filings have no immediate intent and low probability of issuance, lower pre-filing returns relative to non-shelf issuers, and often have been certified in prior SEOs. The evidence indicates that the way firms now use shelf offerings resolves the under-certification problem responsible for the shelf demise in the 1980s (Denis, 1991) and results in smaller market penalties and lower underwriter fees relative to non-shelf offerings. This allows firms with greater uncertainty to take advantage of the shelf option to defer or abandon offers. Additionally, firms often use universal shelf filings and choose between debt and equity offerings based on the prevailing relative market conditions. The second essay examines offer price discounting of traditional and shelf-registered seasoned equity offerings (SEOs). The results indicate that relative to traditional SEOs, shelf discounting during 1982 - June 2004 is similar in magnitude, is influenced by the same factors, and has increased similarly over time. Prior studies attribute the time-series increase of seasoned offer discounting to pre-offer short sale constraints (Rule 10b-21; adopted in 1988). This study provides insights about the effect of Rule 10b-21 by exploiting the fact that shelf-registered offerings were exempt from this regulation until September 2004. The analysis uses the shelf exemption as a control in testing the Rule's effect, and the elimination of the exemption as an "out-of-sample" test. The results suggest that Rule 10b-21 is not associated with the increase in seasoned offer discounts. The gradual increase in discounting over the past two decades is largely due to a shift in the composition of issuers toward firms that have greater stock volatility and pre-offer price uncertainty. / Ph. D.

In deformation based morphometry (DBM) group-wise differences in brain structure are measured using deformable registration and some form of statistical test. However, it is known that DBM results are sensitive to both the registration method and statistical test used. Given the lack of an objective model of group variation it has been difficult to determine the extent of the influence of registration implementation or contraints on DBM analysis. In this thesis, we use registration methods with varying levels of theoretic similarity to study the influence of registration mechanics on DBM results. We show that because of the extent of the influence of registration mechanics on DBM results, analysis of changes should always be made with a thorough understanding of the registration method used. We also show that minor variations in registration methods can lead to large changes in DBM results. When using DBM, it would be imprudent to use only one registration method to draw any conclusions about the variations being studied. In order to provide a more complete representation of inter-group changes, we propose a method for combining multiple registration methods using Dempster-Shafer evidence theory to produce belief maps of categorical changes between groups. We show that the Dempster-Shafer combination produces a unique and easy to interpret belief map of regional changes between and within groups without the complications associated with hypothesis testing. Another, often confounding, element of DBM is the parametric hypothesis test used to specify voxels undergoing significant change between the two groups. The accuracy and reliability of these tests are contingent on a number of fundamental assumptions made about the distribution of the data used in the tests. Many DBM studies often overlook these assumptions and fail to verify their validity for the data being tested. This raises many doubts about the credibility of the results from such tests. In this thesis, we propose to perform statistical analysis on DBM data using nonparametric, distribution independent hypothesis tests. With no data distributional assumptions, these tests provide both increased flexibility and reliability of DBM statistical analysis. / Ph. D.

A commercially available, tripod mounted, ground-based laser scanner was used to assess forest canopies and measure individual tree parameters. The instrument is comparable to scanning airborne light detection and ranging (lidar) technology but gathers data at higher resolution over a more limited scale. The raw data consist of a series of range measurements to visible surfaces taken at known angles relative to the scanner. Data were translated into three dimensional (3D) point clouds with points corresponding to surfaces visible from the scanner vantage point. A 20 m x 40 m permanent plot located in upland deciduous forest at Coweeta, NC was assessed with 41 and 45 scans gathered during periods of leaf-on and leaf-off, respectively. Data management and summary needs were addressed, focusing on the development of registration methods to align point clouds collected from multiple vantage points and minimize the volume of the plot canopy occluded from the scanner's view. Automated algorithms were developed to extract points representing tree bole surfaces, bole centers and ground surfaces. The extracted points served as the control surfaces necessary for registration. Occlusion was minimized by combining aligned point clouds captured from multiple vantage points with 0.1% and 0.34% of the volume scanned being occluded from view under leaf-off and leaf-on conditions, respectively. The point cloud data were summarized to estimate individual tree parameters including diameter at breast height (dbh), upper stem diameters, branch heights and XY positions of trees on the plot. Estimated tree positions were, on average, within 0.4 m of tree positions measured independently on the plot. Canopy height models, digital terrain models and 3D maps of the density of canopy surfaces were created using aligned point cloud data. Finally spatially explicit models of the horizontal and vertical distribution of plant area index (PAI) and leaf area index (LAI) were generated as examples of useful data summaries that cannot be practically collected using existing methods. / Ph. D.

This work consists of three original articles and is focused on the overall question: How can hyperspectral imaging contribute to patient safety and improve outcomes during abdominal surgery? The hypothesis was that HSI is suitable for the intraoperative assessment of tissue structures and decision support in routine clinical use. Spectral imaging was performed with the TIVITA Tissue for open surgery or TIVITA Mini system for laparoscopic HSI from Diaspective Vision GmbH (Am Salzhaff-Pepelow, Germany). Both HSI systems use pushbroom mode and provide 100 spectral channels in the visible and near-infrared spectral range from 500 - 1000 nm. The Number of Effective Pixels is at least 640 × 480 (x-, y-axis), while the field of view and spatial resolution depend on the measurement distance and the used focal length of the objective. Illumination is done by halogen spots for open surgery and broadband LED in the laparoscopic system. The first part of this work aimed to evaluate HSI for the measurement of ischemic conditioning effects of the gastric conduit during esophagectomy. Ischemic preconditioning by dividing major blood vessels of the stomach prior to gastric pull-up is performed to improve the perfusion at the later esophagogastric anastomosis to reduce the risk of leaks. Intraoperative hyperspectral records of the gastric tube were acquired from 22 patients through the mini-thoracotomy. Fourteen of them underwent ischemic conditioning of the stomach several days before the two-step transthoracic esophagectomy and gastric pull-up with intrathoracic anastomosis was performed. The tip of the gastric tube (later esophago-gastric anastomosis) was measured with HSI. These in vivo records showed that the tissue oxygenation of the gastric conduit was significantly higher in patients who underwent ischemic conditioning (78% vs. 66%; p = 0.03). In the second part of this work, a novel hyperspectral imaging system for MIS is described and evaluated to address the requirements for clinical use and high-resolution spectral imaging. Reference objects and resected human tissue were used to show spectral conformity with the approved HSI device for open surgery. Furthermore, varying object distances were investigated and the signal-to-noise ratio (SNR) for different light sources were measured. Measurements with both systems were performed on a human tissue resectate and compared quantitatively. It was shown that the handheld design of the laparoscopic HSI system enables the processing and visualization of spectral data in parallel during acquisition within a few seconds. The obtained measurements from both spectral imaging devices were consistent and a mean SNR of 30 to 43 dB (500 to 950 nm) was found using a standard rigid laparoscope in combination with a broadband LED light source. Finally, in the third part of this work, different image registration methods were investigated to compensate for small movements of the laparoscope and tissue deformations. The obtained image transformation is used to augment the laparoscopic color video with the static HSI data to support intraoperative localization. Multiple feature-based algorithms and a pre-trained deep homography neural network (DH-NN) were evaluated for the estimation of appropriate image transformations (single and multi-homography). The methods were validated with a ground truth dataset of 750 annotated laparoscopic images, that was created during this work, and in vivo data from the TIVITA Mini system. All feature-based single homography methods outperformed the fine-tuned DH-NN in terms of reprojection error, Structural Similarity Index Measure (SSIM), and processing time. The feature detector and descriptor ORB1000 enabled video-rate registration of laparoscopic images on standard hardware with submillimeter accuracy. Therefore, all initially stated research questions could be confirmed with the applied methods. Although technical limitations have been identified, the non-invasive and contact-free measurement principle makes HSI attractive for a variety of surgical disciplines.:1 Introduction 1.1 Interaction of light and biological tissue 1.2 Spectral imaging systems 1.3 Medical applications of spectral imaging 1.4 Intraoperative visualization of spectral data 2 Original Articles 2.1 Evaluation of hyperspectral imaging (HSI) for the measurement of ischemic conditioning effects of the gastric conduit during esophagectomy 2.2 Laparoscopic system for simultaneous high-resolution video and rapid hyperspectral imaging in the visible and near-infrared spectral range 2.3 Comparison of image registration methods for combining laparoscopic video and spectral image data 3 Summary 3.1 Conclusions and Outlook 4 References

No / This study explores the impact of the process of socialisation on pre-registration student nurses views about care, and their personal ability to cope with becoming a nurse. Objectives: It aims to identify the effect time has on participants attitudes and views of care and becoming a nurse, during pre-registration nurse training, by using a descriptive longitudinal qualitative design. Setting: Data collection took place within the School of Health or on student's clinical placement areas, using a random sample of 16 pre-registration student nurses obtained from a convenience sample of 52 volunteers. Methods: Participants were involved in two semi-structured in depth interviews, the first 6-9 months after entering nurse training and the second 6-9 months prior to completion. Interviews were tape recorded, transcribed verbatim and analysed using Morse and Field's (1996) four stages of analysis. Results: Identified changes between data collection stages suggest socialisation results in a loss of idealism about care within nursing, as well as the identification of negative aspects of care. Loss of care is linked to increased abilities to cope with the nursing role, although this is not uniform and some participants clearly discriminate and reject negative exposures. In conclusion this study identifies an under recognised dichotomy between the caring ethos of professional nursing and the professional socialisation processes student nurses are subject to, which directly mitigate against the individual nurses abilities to care.