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1

Center of mass of human's body segments

Adolphe M., Clerval J., Kirchof Z., Lacombe-Delpech R., Zagrodny B.

Mechanics and Mechanical Engineering

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2017

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Vol. 21, nr 3

485--497

EN

In biomechanics, determination of the body’s center of mass has always been an important part of many biomechanical studies. However, it is always a challenge to find it and often obtained results are only estimations, guesses. Indeed, to find someone’s body center of mass isn’t as easy as finding center of mass of simple rigid objects with uniform density, where it usually could be found at the centroid. The human body is different according to the gender, the age, the ethnicity, the physical shape, body fat distribution, etc. As it is composed of bones and muscles, results may differ drastically depending on which muscles are tense or on the body positioning. Nowadays, as a new era of biomechanics is approaching with a superior kind of prosthesis or exoskeletons that calls upon an “augmented humanity”, or even with gait modelling. It is important to find an experimental method that gives precise positioning of such an important data as the center of gravity of body segments, widely available to scientists that would need to go further in their researches, without having to use sophisticated equipment or time-consuming methods.

2

Knee bone segmentation from MRI: A classification and literature review

Aprovitola A., Gallo L.

Biocybernetics and Biomedical Engineering

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2016

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Vol. 36, no. 2

437--449

EN

Segmentation of cartilage from Magnetic Resonance (MR) images has evolved as a tool for the diagnosis of knee joint pathologies. However, accuracy and reproducibility of automated methods of cartilage segmentation may require the prior extraction of bone surfaces from MR imaging sequences specifically designed to evidence the cartilage and not the bone. Thus a priori knowledge of knee joint structures and fully automated segmentation methods are adopted to provide reliable detection of bone surfaces. In this paper, we review knee bone segmentation methods from MR images. We classified the methods proposed in literature according to the level of a priori knowledge, the level of automation and the level of manual user interaction. Furthermore we discuss the segmentation results in literature in relation to the MR sequences used to image the bone.

3

The segmentation method usage in an assessment sheet analysis

Urbański K., Wrzosek A.

Poznan University of Technology Academic Journals. Electrical Engineering

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2011

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No. 66

169--176

EN

The paper presents a prototype system for automatic data acquisition and analysis of student's progress based on assessment of the work papers. The instructor saves the points aquired by the students at the classes. Then software makes an analyze of collected data. Presented prototype package provides both an analysis of assessment cards as well as their generation. The package uses an implementation of the OMR (Optical Mark Recognition) algorithm. The software was developed in MATLAB.

4

3D segmentation and analysis of marcroporous alumino-silicate

Moreaud M., Celse B., Fanny T.

Inżynieria Materiałowa

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2008

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Vol. 29, nr 4

433-438

EN

We present a method for the segmentation and analysis of a macroporous alumino-silicate. This catalytic material is used for instance in petroleum industries for the conversion of heavy crude oil. The efficiency of such catalysts is strongly linked to their texture. To analyze itsmorphology, we use three-dimensional transmission electron microscopy (3D-TEM) images. These images allow 3D information at the nanometric scale. A segmentation method is proposed to correctly segment the material and a method for estimating the internal porous network is presented. It allows an accurate estimation of the volume of pores keeping intact the irregularity of the surface. Some measurements are performed on this extracted volume. Porosity and specific surface area are calculated and compared with global physical measurement methods. An analysis of the connections between the pores is proposed either. This method used a pore-to-pore distance map processed using geodesic constrained distance propagations. It allows the detection of pores that are not extended through the entire material. A global quantification of the connections between the pores is also possible.

PL

Praca prezentuje metodę segmentacji i analizy makroporowatego glinokrzemianu. Ten materiał katalityczny jest stosowany na przykład w przemyśle petrochemicznym do przetwarzania surowej, ciężkiej ropy naftowej. Wydajność katalizatora jest silnie związana z jego teksturą. W celu analizy morfologii katalizatora zastosowano obrazy z trójwymiarowej mikroskopii transmisyjnej (3D-TEM). Te obrazy dostarczają informacji na poziomie nanoskali. Zaproponowano metodę segmentacji w celu poprawnego podziału materiału i metodę estymacji wewnętrznej siatki porów. Metoda umożliwia dokładną estymację objętości porów, pozostawiając nienaruszoną nieregularność powierzchni. Niektóre pomiary są wykonywane na objętości wyodrębnionej. Obliczono porowatość i powierzchnię względną i porównywno z ogólnymi metodami fizycznymi. Zaproponowano również metodę analizy połączeń pomiędzy porami. Metoda ta wykorzystuje mapę odległości między porami i jej przekształcenia geodezyjne. Umożliwia detekcję porów nie rozprzestrzenioną na całość objętości materiału. Możliwa jest również globalna ocena ilościowa połączeń między porami.

5

Knowledge driven segmentation of specific objects : a composed method

Flores-Parra I., Bienvenido J.

Image Processing & Communications

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2002

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Vol. 8, no 2

57-70

EN

Segmentation methods have been used extensively in image analysis, automatic industrial classification and defective pieces searching. Starting with the analysis of satellite images, we found that using some windows driven segmentation algorithms with an adequate set of parameters, it was possible to segmentate only specific parts of the images. Taking advantage of this behavior, we developed a wide set of alternative segmentation algorithms. Combining, later, these previous techniques into a composed system that worked with mobile windows. Different alternatives (method, parameters) generate different segmentated images, which reveal different set of objects, requiring different resources. The composition of the different segmentation mechanisms and its later application is done using a knowledge model that integrates previous partial work models. In this paper, it is showed this knowledge model of the segmentation process that integrates a wide set of techniques.