Mems based bridge monitoring supported by image-assisted total station

In this study, the feasibility of Micro-Electro-Mechanical System (MEMS) accelerometers and an image-assisted total station (IATS) for short-and long-term deformation monitoring of bridge structures is investigated. The MEMS sensors of type BNO055 from Bosch as part of a geo-sensor network are mounted at different positions of the bridge structure. In order to degrade the impact of systematic errors on the acceleration measurements, the deterministic calibration parameters are determined for fixed positions using a KUKA youBot in a climate chamber over certain temperature ranges. The measured acceleration data, with a sampling frequency of 100 Hz, yields accurate estimates of the modal parameters over short time intervals but suffer from accuracy degradation for absolute position estimates with time. To overcome this problem, video frames of a passive target, attached in the vicinity of one of the MEMS sensors, are captured from an embedded on-axis telescope camera of the IATS of type Leica Nova MS50 MultiStation with a practical sampling frequency of 10 Hz. To identify the modal parameters such as eigenfrequencies and modal damping for both acceleration and displacement time series, a damped harmonic oscillation model is employed together with an autoregressive (AR) model of coloured measurement noise. The AR model is solved by means of a generalized expectation maximization (GEM) algorithm. Subsequently, the estimated model parameters from the IATS are used for coordinate updates of the MEMS sensor within a Kalman filter approach. The experiment was performed for a synthetic bridge and the analysis shows an accuracy level of sub-millimetre for amplitudes and much better than 0.1 Hz for the frequencies. © 2019 M. Omidalizarandi et al

HIGH ACCURATE POINTWISE (GEO-)REFERENCING OF A K-TLS BASED MULTI-SENSOR-SYSTEM

In recent years, the requirements in the industrial production, e.g., ships or planes, have been increased. In addition to high accuracy requirements with a standard deviation of 1 mm, an efficient 3D object capturing is required. In terms of efficiency, kinematic laser scanning (k-TLS) has been proven its worth in recent years. It can be seen as an alternative to the well established static terrestrial laser scanning (s-TLS). However, current k-TLS based multi-sensor-systems (MSS) are not able to fulfil the high accuracy requirements. Thus, a new k-TLS based MSS and suitable processing algorithms have to be developed. In this contribution a new k-TLS based MSS will be presented. The main focus will lie on the (geo-)referencing process. Due to the high accuracy requirements, a novel procedure of external (geo-)referencing is used here. Hereby, a mobile platform, which is equipped with a profile laser scanner, will be tracked by a laser tracker. Due to the fact that the measurement frequency of the laser scanner is significantly higher than the measurement frequency of the laser tracker a direct point wise (geo-)referencing is not possible. To enable this a Kalman filter model is set up and implemented. In the prediction step each point is shifted according to the determined velocity of the platform. Because of the nonlinear motion of the platform an iterative extended Kalman filter (iEKF) is used here. Furthermore, test measurements of a panel with the k-TLS based MSS and with s-TLS were carried out. To compare the results, the 3D distances with the M3C2-algorithm between the s-TLS 3D point cloud and the k-TLS 3D point cloud are estimated. It can be noted, that the usage of a system model for the (geo-)referencing is essential. The results show that the mentioned high accuracy requirements have been achieved

Optimisation of the calibration process of a k-tls based multi-sensor-system by genetic algorithms

In recent years, the requirements in the industrial production of elongated objects, e.g., aircraft, have been increased. An essential aspect of the production process is the 3D object detection as well as the qualitative assessment of the captured data. On the one hand high accuracy requirements with a 3D standard deviation of σ3D Combining double low line 1 mm have to be fulfilled, on the other hand an efficient 3D object capturing is needed. In terms of efficiency, kinematic terrestrial laser scanning (k-TLS) has proven its strength in the recent years. It can be seen as an alternative and is even more powerful than to the well established static terrestrial laser scanning (s-TLS). In order to perform a high accurate 3D object capturing with k-TLS, the 3D object capturing of the initial sensor, the (geo-)referencing of the mobile platform, the synchronisation of all sensors and the system calibration, which means the determination of six extrinsic parameters have to be performed with suitable accuracy. Within this contribution we focus on the system calibration. Therefore an approach based on known reference geometries, here planes, is used (Strübing and Neumann, 2013). As a result, the lever arm and boresight angles are determined. Hereby the number as well as the position and orientation of the reference geometries is of importance. Therefore, an optimal arrangement has to be found. Here a sensitive analysis based on uncertainty propagation is used. A selective search of an optimised arrangement is carried out by a genetic algorithm. Within some examples we demonstrate some theoretical aspects and how an optimisation of the reference geometry arrangement can be achieved

Few smooth d-polytopes with n lattice points

We prove that, for fixed n there exist only finitely many embeddings of Q-factorial toric varieties X into P^n that are induced by a complete linear system. The proof is based on a combinatorial result that for fixed nonnegative integers d and n, there are only finitely many smooth d-polytopes with n lattice points. We also enumerate all smooth 3-polytopes with at most 12 lattice points. In fact, it is sufficient to bound the singularities and the number of lattice points on edges to prove finiteness.Comment: 20+2 pages; major revision: new author, new structure, new result

Discrepancy between German S3 Guideline Recommendations and Daily Urologic Practice in the Management of Nonmuscle Invasive Bladder Cancer: Results of a Binational Survey

Introduction: Guideline recommendations are meant to help minimize morbidity and to improve the care of nonmuscle invasive bladder cancer (NMIBC) patients but studies have suggested an underuse of guideline-recommended care. The aim of this study was to evaluate the level of adherence of German and Austrian urologists to German guideline recommendations. Methods: A survey of 27 items evaluating diagnostic and therapeutic recommendations (15 cases of strong consensus and 6 cases of consensus) for NMIBC was administered among 14 urologic training courses. Survey construction and realization followed the checklist for reporting results of internet e-surveys and was approved by an internal review board. Results: Between January 2018 and June 2019, a total of 307 urologists responded to the questionnaire, with a mean response rate of 71%. The data showed a weak role of urine cytology (54%) for initial diagnostics although it is strongly recommended by the guideline. The most frequently used supporting diagnostic tool during transurethral resection of the bladder was hexaminolevulinate (95%). Contrary to the guideline recommendation, 38% of the participants performed a second resection in the case of pTa low-grade NMIBC. Correct monitoring of Bacille Calmette-Guerin (BCG) response with cystoscopy and cytology was performed by only 34% of the urologists. Conclusions: We found a discrepancy between certain guideline recommendations and daily routine practice concerning the use of urine cytology for initial diagnostics, instillation therapy with a low monitoring rate of BCG response, and follow-up care with unnecessary second resection after pTa low-grade NMIBC in particular. Our survey showed a moderate overall adherence rate of 73%. These results demonstrate the need for sharpening awareness of German guideline recommendations by promoting more intense education of urologists to optimize NMIBC care thus decreasing morbidity and mortality rates

Hidden politics of power and governmentality in transitional justice and peacebuilding:The problem of ‘bringing the local back in’

This paper examines ‘the local’ in peacebuilding by examining how ‘local’ transitional justice projects can become spaces of power inequalities. The paper argues that focusing on how ‘the local’ contests or interacts with ‘the international’ in peacebuilding and post-conflict contexts obscures contestations and power relations amongst different local actors, and how inequalities and power asymmetries can be entrenched and reproduced through internationally funded local projects. The paper argues that externally funded projects aimed at emancipating ‘locals’ entrench inequalities and create local elites that become complicit in governing the conduct and participation of other less empowered ‘locals’. The paper thus proposes that specific local actors—often those in charge of externally funded peacebuilding projects—should also be conceptualised as governing agents: able to discipline and regulate other local actors’ voices and their agency, and thus (re)construct ideas about what ‘the local’ is, or is not

Large scale international replication and meta-analysis study confirms association of the 15q14 locus with myopia. The CREAM consortium

Myopia is a complex genetic disorder and a common cause of visual impairment among working age adults. Genome-wide association studies have identified susceptibility loci on chromosomes 15q14 and 15q25 in Caucasian populations of European ancestry. Here, we present a confirmation and meta-analysis study in which we assessed whether these two loci are also associated with myopia in other populations. The study population comprised 31 cohorts from the Consortium of Refractive Error and Myopia (CREAM) representing 4 different continents with 55,177 individuals; 42,845 Caucasians and 12,332 Asians. We performed a meta-analysis of 14 single nucleotide polymorphisms (SNPs) on 15q14 and 5 SNPs on 15q25 using linear regression analysis with spherical equivalent as a quantitative outcome, adjusted for age and sex. We calculated the odds ratio (OR) of myopia versus hyperopia for carriers of the top-SNP alleles using a fixed effects meta-analysis. At locus 15q14, all SNPs were significantly replicated, with the lowest P value 3.87 × 10 -12 for SNP rs634990 in Caucasians, and 9.65 × 10 -4 for rs8032019 in Asians. The overall meta-analysis provided P value 9.20 × 10 -23 for the top SNP rs634990. The risk of myopia versus hyperopia was OR 1.88 (95 % CI 1.64, 2.16, P < 0.001) for homozygous carriers of the risk allele at the top SNP rs634990, and OR 1.33 (95 % CI 1.19, 1.49, P < 0.001) for heterozygous carriers. SNPs at locus 15q25 did not replicate significantly (P value 5.81 × 10 -2 for top SNP rs939661). We conclude that common variants at chromosome 15q14 influence susceptibility for myopia in Caucasian and Asian populations world-wide. © The Author(s) 2012

The Politics of Institutional Reform and Post-Conflict Violence in Nepal

How does the reform of state institutions shape prospects for peace after war? Existing research on the institutional causes of peace focuses on how institutional designs, as the outcomes of reform processes, reduce post-conflict violence and promote peace. The literature does not, however, adequately address how the politics that characterise reform processes affect the legitimacy of institutions and whether or not violent protest against these institutions ultimately takes place. This focus risks omitting key explanations of how institutional reforms contribute to peace and the mechanisms by which this occurs. By examining the case of Nepal, where clashes between protesters and security forces killed almost 60 people between August 2015 and January 2016, this study shows that emotional rhetoric, elite control of decision-making, backtracking on previous commitments, the acceleration of reform processes, and the embedding of single reforms in a 'concert' of reforms that, as a whole, sparks fears of discrimination are all factors that can lead to post-conflict violence