Linear accuracy and reliability of volume data sets acquired by two CBCT-devices and an MSCT using virtual models: A comparativein-vitrostudy

2015 ◽  
Vol 74 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Johannes Wikner ◽  
Henning Hanken ◽  
Christine Eulenburg ◽  
Max Heiland ◽  
Alexander Gröbe ◽  
...  
2003 ◽  
Vol 47 (2) ◽  
pp. 43-51 ◽  
Author(s):  
M.B. Beck ◽  
Z. Lin

In spite of a long history of automated instruments being deployed in the water industry, only recently has the difficulty of extracting timely insights from high-grade, high-volume data sets become an important problem. Put simply, it is now relatively easy to be “data-rich”, much less easy to become “information-rich". Whether the availability of so many data arises from “technological push” or the “demand pull” of practical problem solving is not the subject of discussion. The paper focuses instead on two issues: first, an outline of a methodological framework, based largely on the algorithms of (on-line) recursive estimation and involving a sequence of transformations to which the data can be subjected; and second, presentation and discussion of the results of applying these transformations in a case study of a biological system of wastewater treatment. The principal conclusion is that the difficulty of transforming data into information may lie not so much in coping with the high sampling intensity enabled by automated monitoring networks, but in coming to terms with the complexity of the higher-order, multi-variable character of the data sets, i.e., in interpreting the interactions among many contemporaneously measured quantities.


2009 ◽  
Vol 9 ◽  
pp. 1423-1437 ◽  
Author(s):  
Stefan H. Geyer ◽  
Timothy J. Mohun ◽  
Wolfgang J. Weninger

The creation of highly detailed, three-dimensional (3D) computer models is essential in order to understand the evolution and development of vertebrate embryos, and the pathogenesis of hereditary diseases. A still-increasing number of methods allow for generating digital volume data sets as the basis of virtual 3D computer models. This work aims to provide a brief overview about modern volume data–generation techniques, focusing on episcopic 3D imaging methods. The technical principles, advantages, and problems of episcopic 3D imaging are described. The strengths and weaknesses in its ability to visualize embryo anatomy and labeled gene product patterns, specifically, are discussed.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Guoyu Du ◽  
Xuehua Li ◽  
Lanjie Zhang ◽  
Libo Liu ◽  
Chaohua Zhao

The K-means algorithm has been extensively investigated in the field of text clustering because of its linear time complexity and adaptation to sparse matrix data. However, it has two main problems, namely, the determination of the number of clusters and the location of the initial cluster centres. In this study, we propose an improved K-means++ algorithm based on the Davies-Bouldin index (DBI) and the largest sum of distance called the SDK-means++ algorithm. Firstly, we use the term frequency-inverse document frequency to represent the data set. Secondly, we measure the distance between objects by cosine similarity. Thirdly, the initial cluster centres are selected by comparing the distance to existing initial cluster centres and the maximum density. Fourthly, clustering results are obtained using the K-means++ method. Lastly, DBI is used to obtain optimal clustering results automatically. Experimental results on real bank transaction volume data sets show that the SDK-means++ algorithm is more effective and efficient than two other algorithms in organising large financial text data sets. The F-measure value of the proposed algorithm is 0.97. The running time of the SDK-means++ algorithm is reduced by 42.9% and 22.4% compared with that for K-means and K-means++ algorithms, respectively.


Skull Base ◽  
2007 ◽  
Vol 17 (S 1) ◽  
Author(s):  
Matthias Kirsch ◽  
Thomas Meyer ◽  
Dino Podlesek ◽  
Ute Morgenstern ◽  
Rüdiger von Kummer ◽  
...  

2006 ◽  
Vol 45 (01) ◽  
pp. 19-26 ◽  
Author(s):  
G. Fischer ◽  
F. Hanser ◽  
M. Seger ◽  
C. Hintermüller ◽  
R. Modre-Osprian ◽  
...  

Summary Objectives: This paper presents an efficient approach for extracting myocardial structures from given atrial and ventricular blood masses to enable non-invasive estimation of electrical excitation in human atria and ventricles. Methods: Based on given segmented atrial and ventricular blood masses, the approach constructs the myocardial structure directly, in the case that the myocardium can be detected in the volume data, or by using mean model information, in the case that the myocardium cannot be seen in the volume data due to image modalities or artefacts. The approach employs mathematical and gray-value morphology operations. Regulated by the spatial visibility of the myocardial structure in the medical image data especially the atrial myocardium needs to be estimated repeatedly using the a-priori knowledge given by the anatomy. Results: The approach was tested using eight patient data sets. The reconstruction process yielded satisfying results with respect to an efficient generation of a volume conductor model which is essential when trying to implement the estimation of electrical excitation in clinical application. Conclusion: The approach yields ventricular and atrial models that qualify for cardiac source imaging in a clinical setting.


Author(s):  
Abdelrahman Yehia ◽  
Mohamed Safy ◽  
Ahmed S. Amein

Multi-sensor remote sensing data can significantly improve the interpretation and usage of large volume data sources. A combination of satellite Synthetic Aperture Radar (SAR) data and optical sensors enables the use of complementary features of the same image. In this paper, SAR data is injected into optical image using a combining fusion method based on the integration of wavelet Transform and IHS (Intensity, Hue, and Saturation) transform. Not only to preserve the spectral information of the original (MS) image, but also to maintain the spatial content of the high-resolution SAR image. Two data sets are used to evaluate the proposed fusion algorithm: one of them is Pleiades, Turkey and the other one is Boulder, Colorado, USA. The different fused outputs are compared using different image quality indices. Visual and statistical assessment of the fused outputs displays that the proposed approach has an effective translation from SAR to the optical image. Hence, enhances the SAR image interpretability.


Sign in / Sign up

Export Citation Format

Share Document