An Iterative Quality-Based Localization Algorithm for Ad Hoc Networks

An iterative quality-based algorithm for location discovery is presented which can be used in wireless ad hoc sensor networks. The algorithm will take the reliability of measurements into account and will produce a reliability index for every estimated location using a statistical approach. The algorithm can also work in a hybrid network with different kinds of distance measuring techniques. It will use the reliability of each of these methods in the final result. Satisfactory results can be achieved with this approach

Dual Track or Academic Route for Auditors

In the Netherlands auditors can be trained in a part-time educational track in which students combine working and studying or in a full-time educational track. The former training is relatively firm-specific whereas the latter training is relatively general. Applying human capital theory, we expect higher wage growth for full-time educated auditors than for dual-educated auditors. Furthermore, full-time educated auditors may have better outside options than part-time educated auditors. This may make it easier for them to switch employers than for the part-time educated auditors. The predictions on tenure and wages of differently educated auditors are supported by the estimation results in this paper. The part-time, dual track appears an important route for students from a lower socioeconomic background

Modeling charity donations: target selection, response time and gift size

Charitable organizations often consider direct mailings to raise donations. Obviously, it is important for a charity to make a profitable selection from available mailing lists, which can be its own list or a list obtained elsewhere. For this purpose, a charitable organization usually has to address the following four questions: 1. Who should we send a mailing? 2. Who is likely to respond to that mailing? 3. How much time will it take for such an individual to respond? 4. How much money will this individual donate? Several techniques for addressing one or more of these questions have been suggested in the literature. For example, Bult and Wansbeek (1995) develop a model that addresses question 2. Otter et al. (1997) develop a model that jointly considers questions 2 and 4. In practice one often relies on techniques such as RFM-based decision rules (Bauer 1988) in order to answer question 1. In this paper we develop a model which enables a charitable organization to make an optimal selection from its own mailing list, while simultaneously considering the four questions above. Hence, our model consists of four components with a possible non-zero correlation structure. The explanatory variables in each of these components are RFM-type variables, where these are allowed to have different effects on the various variables to be explained. In particular, we show that the first component is essential when a target selection model is applied on a database. Neglecting this component can generate a substantial bias in the results of subsequent analysis. The various model parameters are estimated by maximum likelihood. We illustrate our model using a random drawing of about 5,300 individuals from the database of a large Dutch charitable organization. Our empirical results indicate the relevance of the non-zero correlation across the model components, and the relevance of taking account of the target selection part. We find some RFM variables to have effects with opposite signs on the probability to respond, the time for response and the donation. It is found that the most profitable individuals are not the ones who have maximum scores on the RFM variables. We conclude with a discussion of various further research topics

Validation of a simplified intravascular ultrasound core lab analysis method in stented coronary arteries

OBJECTIVES: To validate a simplified core laboratory intravascular ultrasound (IVUS) analysis method based on frames with visually determined minimal lumen areas (MLAs) as compared with a comprehensive (per frame) analysis method. BACKGROUND: IVUS‐guided percutaneous coronary intervention has proven to be superior to angiography‐guided stenting. In clinical practice, cross‐sections with visually determined MLA are measured to determine lesion severity or minimal stent area (MSA), however, its accuracy has not been compared with a comprehensive per frame analysis method. METHODS: A total of 50 stented coronary segments of anonymized core lab datasets were analyzed using a comprehensive analysis method and reanalyzed by two core lab analysts using the simplified method including a maximum of seven frames to be analyzed (the visually determined MSA, the first and last frame, and the MLA of each reference segment). The main parameters of interest were MSA, MLA in the reference segments, and plaque burden. RESULTS: The simplified method showed moderate agreement for measurement of the proximal MLA (7.51 ± 2.52 vs. 6.32 ± 1.88 mm(2), intraclass correlation coefficient [ICC] = 0.73), good agreement for the distal MLA (5.41 ± 1.85 vs. 5.11 ± 1.38 mm(2), ICC = 0.84) and plaque burden proximal (0.49 ± 0.12 vs. 0.50 ± 0.11, ICC = 0.88), and excellent agreement for the MSA (5.35 ± 1.05 vs. 5.32 ± 0.99 mm(2), ICC = 0.94) and plaque burden distal (0.47 ± 0.14 vs. 0.47 ± 0.12, ICC = 0.92), when compared with the comprehensive analysis method. Inter‐ and intraobserver analysis revealed good‐to‐excellent agreement for all parameters. CONCLUSIONS: Measuring poststenting IVUS cross‐sections with visually determined MLAs by experienced core lab analysts is an accurate and reproducible method to identify MLAs

Antiviral treatment in schizophrenia:a randomized pilot PET study on the effects of valaciclovir on neuroinflammation

BACKGROUND: Patients with schizophrenia experience cognitive impairment, which could be related to neuroinflammation in the hippocampus. The cause for such hippocampal inflammation is still unknown, but it has been suggested that herpes virus infection is involved. This study therefore aimed to determine whether add-on treatment of schizophrenic patients with the anti- viral drug valaciclovir would reduce hippocampal neuroinflammation and consequently improve cognitive symptoms.METHODS: We performed a double-blind monocenter study in 24 male and female patients with schizophrenia, experiencing active psychotic symptoms. Patients were orally treated with the anti-viral drug valaciclovir for seven consecutive days (8 g/day). Neuroinflammation was measured with Positron Emission Tomography using the translocator protein ligand [ 11C]-PK11195, pre-treatment and at seven days post-treatment, as were psychotic symptoms and cognition. RESULTS: Valaciclovir treatment resulted in reduced TSPO binding (39%) in the hippocampus, as well as in the brainstem, frontal lobe, temporal lobe, parahippocampal gyrus, amygdala, parietal lobe, occipital lobe, insula and cingulate gyri, nucleus accumbens and thalamus (31-40%) when using binding potential (BPND) as an outcome. With total distribution volume (VT) as outcome we found essentially the same results, but associations only approached statistical significance ( p = 0.050 for hippocampus). Placebo treatment did not affect neuroinflammation. No effects of valaciclovir on psychotic symptoms or cognitive functioning were found. CONCLUSION: We found a decreased TSPO binding following antiviral treatment, which could suggest a viral underpinning of neuroinflammation in psychotic patients. Whether this reduced neuroinflammation by treatment with valaciclovir has clinical implications and is specific for schizophrenia warrants further research.</p