Measurement of intervertebral cervical motion by means of dynamic X-ray image processing and data interpolation

Accurate measurement of intervertebral kinematics of the cervical spine can support the diagnosis of widespread diseases related to neck pain, such as chronic whiplash dysfunction, arthritis, and segmental degeneration. The natural inaccessibility of the spine, its complex anatomy, and the small range of motion only permit concise measurement in vivo. Low dose X-ray fluoroscopy allows time-continuous screening of cervical spine during patient's spontaneous motion. To obtain accurate motion measurements, each vertebra was tracked by means of image processing along a sequence of radiographic images. To obtain a time-continuous representation of motion and to reduce noise in the experimental data, smoothing spline interpolation was used. Estimation of intervertebral motion for cervical segments was obtained by processing patient's fluoroscopic sequence; intervertebral angle and displacement and the instantaneous centre of rotation were computed. The RMS value of fitting errors resulted in about 0.2 degree for rotation and 0.2 mm for displacements. © 2013 Paolo Bifulco et al.

A stable graph-based representation for object recognition through high-order matching

Many Object recognition techniques perform some flavour of point pattern matching between a model and a scene. Such points are usually selected through a feature detection algorithm that is robust to a class of image transformations and a suitable descriptor is computed over them in order to get a reliable matching. Moreover, some approaches take an additional step by casting the correspondence problem into a matching between graphs defined over feature points. The motivation is that the relational model would add more discriminative power, however the overall effectiveness strongly depends on the ability to build a graph that is stable with respect to both changes in the object appearance and spatial distribution of interest points. In fact, widely used graph-based representations, have shown to suffer some limitations, especially with respect to changes in the Euclidean organization of the feature points. In this paper we introduce a technique to build relational structures over corner points that does not depend on the spatial distribution of the features. © 2012 ICPR Org Committee.

A study of the perceived effectiveness of existing recruitment and general institution -wide practices used to enhance women and minority full -time faculty representation at Florida's public universities

As a federal contractor, the State University System of Florida (SUSF) has instituted a wide range of affirmative action practices to hire and promote women and minorities. Should affirmative action be abolished, universities valuing a diverse faculty will have to rely on voluntary practices to attract members of these groups. I explored the present use and perceived effectiveness of recruitment and institution-wide practices used to promote a diverse workforce and identified those practices considered very effective by informed respondents at the nine participating universities. ^ Two questionnaires were used for data collection. Selected recruitment and general institution-wide best practices found in previous studies were used as benchmarks for comparison with existing practices. The questionnaires also included an open-ended question to identify indigenous practices. A follow-up semi-structured interview was conducted to gather information regarding the background of identified practices. ^ Two overall themes emerged from the study. The first was the perception among respondents that women have made substantial gains in faculty representation. This perception is substantiated by actual percentage of women tenure-earning faculty. The second theme was that many of the practices considered very effective are affirmative action-driven, providing women and minorities considerations not afforded White males. These practices, because they single out members of one group over another based on gender and race/ethnicity may become illegal should affirmative action mandates be abolished. ^ Analysis of the data revealed that universities with the highest percentage of practices considered effective and universities located in the most urban areas of the state were the universities with the highest percentage of minority tenure-earning faculty. There appears to be no similar relationship between universities in urban areas and those with the highest percentage of practices considered effective and women tenure-earning faculty representation. The most frequently identified recruitment practice was the development of a receptive institutional image for women and minorities. The most frequently identified practice in promoting a receptive institutional climate was the use of conflict resolution processes and grievance procedures. Five themes also emerged from the 22 barriers in recruiting women and minority full-time faculty identified by the respondents. The most commonly identified barriers were related to a lack of financial resources to support effective practices. ^

XML storage and retrieval using the semantic binary object -oriented database system (SEM-ODB)

Over the past five years, XML has been embraced by both the research and industrial community due to its promising prospects as a new data representation and exchange format on the Internet. The widespread popularity of XML creates an increasing need to store XML data in persistent storage systems and to enable sophisticated XML queries over the data. The currently available approaches to addressing the XML storage and retrieval issue have the limitations of either being not mature enough (e.g. native approaches) or causing inflexibility, a lot of fragmentation and excessive join operations (e.g. non-native approaches such as the relational database approach). ^ In this dissertation, I studied the issue of storing and retrieving XML data using the Semantic Binary Object-Oriented Database System (Sem-ODB) to leverage the advanced Sem-ODB technology with the emerging XML data model. First, a meta-schema based approach was implemented to address the data model mismatch issue that is inherent in the non-native approaches. The meta-schema based approach captures the meta-data of both Document Type Definitions (DTDs) and Sem-ODB Semantic Schemas, thus enables a dynamic and flexible mapping scheme. Second, a formal framework was presented to ensure precise and concise mappings. In this framework, both schemas and the conversions between them are formally defined and described. Third, after major features of an XML query language, XQuery, were analyzed, a high-level XQuery to Semantic SQL (Sem-SQL) query translation scheme was described. This translation scheme takes advantage of the navigation-oriented query paradigm of the Sem-SQL, thus avoids the excessive join problem of relational approaches. Finally, the modeling capability of the Semantic Binary Object-Oriented Data Model (Sem-ODM) was explored from the perspective of conceptually modeling an XML Schema using a Semantic Schema. ^ It was revealed that the advanced features of the Sem-ODB, such as multi-valued attributes, surrogates, the navigation-oriented query paradigm, among others, are indeed beneficial in coping with the XML storage and retrieval issue using a non-XML approach. Furthermore, extensions to the Sem-ODB to make it work more effectively with XML data were also proposed. ^

Digital signal processing implementation for near real-time wavelet transformation system for binary images

Communication has become an essential function in our civilization. With the increasing demand for communication channels, it is now necessary to find ways to optimize the use of their bandwidth. One way to achieve this is by transforming the information before it is transmitted. This transformation can be performed by several techniques. One of the newest of these techniques is the use of wavelets. Wavelet transformation refers to the act of breaking down a signal into components called details and trends by using small waveforms that have a zero average in the time domain. After this transformation the data can be compressed by discarding the details, transmitting the trends. In the receiving end, the trends are used to reconstruct the image. In this work, the wavelet used for the transformation of an image will be selected from a library of available bases. The accuracy of the reconstruction, after the details are discarded, is dependent on the wavelets chosen from the wavelet basis library. The system developed in this thesis takes a 2-D image and decomposes it using a wavelet bank. A digital signal processor is used to achieve near real-time performance in this transformation task. A contribution of this thesis project is the development of DSP-based test bed for the future development of new real-time wavelet transformation algorithms.

Algorithms for super-resolution of images based on Sparse Representation and Manifolds

lmage super-resolution is defined as a class of techniques that enhance the spatial resolution of images. Super-resolution methods can be subdivided in single and multi image methods. This thesis focuses on developing algorithms based on mathematical theories for single image super­ resolution problems. lndeed, in arder to estimate an output image, we adopta mixed approach: i.e., we use both a dictionary of patches with sparsity constraints (typical of learning-based methods) and regularization terms (typical of reconstruction-based methods). Although the existing methods already per- form well, they do not take into account the geometry of the data to: regularize the solution, cluster data samples (samples are often clustered using algorithms with the Euclidean distance as a dissimilarity metric), learn dictionaries (they are often learned using PCA or K-SVD). Thus, state-of-the-art methods still suffer from shortcomings. In this work, we proposed three new methods to overcome these deficiencies. First, we developed SE-ASDS (a structure tensor based regularization term) in arder to improve the sharpness of edges. SE-ASDS achieves much better results than many state-of-the- art algorithms. Then, we proposed AGNN and GOC algorithms for determining a local subset of training samples from which a good local model can be computed for recon- structing a given input test sample, where we take into account the underlying geometry of the data. AGNN and GOC methods outperform spectral clustering, soft clustering, and geodesic distance based subset selection in most settings. Next, we proposed aSOB strategy which takes into account the geometry of the data and the dictionary size. The aSOB strategy outperforms both PCA and PGA methods. Finally, we combine all our methods in a unique algorithm, named G2SR. Our proposed G2SR algorithm shows better visual and quantitative results when compared to the results of state-of-the-art methods.

Unsettling Histories: Representation and Indigenous Creative Art Praxis in Official Indian Residential School Redress

This dissertation offers an investigation of the role of visual strategies, art, and representation in reconciling Indian Residential School history in Canada. This research builds upon theories of biopolitics, settler colonialism, and race to examine the project of redress and reconciliation as nation and identity building strategies engaged in the ongoing structural invasion of settler colonialism. It considers the key policy moments and expressions of the federal government—from RCAP to the IRSSA and subsequent apology—as well as the visual discourse of reconciliation as it works through archival photography, institutional branding, and commissioned works. These articulations are read alongside the creative and critical work of Indigenous artists and knowledge producers working within and outside of hegemonic structures on the topics of Indian Residential School history and redress. In particular the works of Jeff Thomas, Adrian Stimson, Krista Belle Stewart, Christi Belcourt, Luke Marston, Peter Morin, and Carey Newman are discussed in this dissertation. These works must be understood in relationship to the normative discourse of reconciliation as a legitimizing mechanism of settler colonial hegemony. Beyond the binary of cooptation and autonomous resistance, these works demonstrate the complexity of representing Indigeneity: as an ongoing site of settler colonial encounter and simultaneously the forum for the willful refusal of contingency or containment.

Fast 2D/3D object representation with growing neural gas

This work presents the design of a real-time system to model visual objects with the use of self-organising networks. The architecture of the system addresses multiple computer vision tasks such as image segmentation, optimal parameter estimation and object representation. We first develop a framework for building non-rigid shapes using the growth mechanism of the self-organising maps, and then we define an optimal number of nodes without overfitting or underfitting the network based on the knowledge obtained from information-theoretic considerations. We present experimental results for hands and faces, and we quantitatively evaluate the matching capabilities of the proposed method with the topographic product. The proposed method is easily extensible to 3D objects, as it offers similar features for efficient mesh reconstruction.

Between representation and figuration. Nouvelle Vague’s cinema: a history revision

50 years after the birth of the Nouvelle Vague, the inheritance that the contemporary cinema receives from it is inevitable. Figures and visual motifs; stories, themes, faces or common places; aesthetic and language devices. The echoes appear in various ways, each affiliation involves a different relationship and therefore a dissimilar approximation to its analysis. And yet, both the academy and the film critics maintain their will to think the Nouvelle Vague as a whole, a universe, a stream or an aesthetic trend. However, does a Nouvelle Vague’s aesthetic exist? And if so: why and how to address their historical revision? Taking Deleuze’s thesis on the time-image and Serge Daney’s assertion according to which 50 years after the birth of the Nouvelle Vague, the inheritance that the contemporary cinema receives from it is inevitable. Figures and visual motifs; stories, themes, faces or common places; aesthetic and language devices. The echoes appear in various ways, each affiliation involves a different relationship and therefore a dissimilar approximation to its analysis. And yet, both the academy and the film critics maintain their will to think the Nouvelle Vague as a whole, a universe, a stream or an aesthetic trend. However, does a Nouvelle Vague’s aesthetic exist? And if so: why and how to address their historical revision? Taking Deleuze’s thesis on the time-image and Serge Daney’s assertion according to which

Durability performance of self-compacting concrete (SCC) with binary and ternary mixes of fly ash and limestone filler

The basic objective of this work is to evaluate the durability of self-compacting concrete (SCC) produced in binary and ternary mixes using fly ash (FA) and limestone filler (LF) as partial replacement of cement. The main characteristics that set SCC apart from conventional concrete (fundamentally its fresh state behaviour) essentially depend on the greater or lesser content of various constituents, namely: greater mortar volume (more ultrafine material in the form of cement and mineral additions); proper control of the maximum size of the coarse aggregate; use of admixtures such as superplasticizers. Significant amounts of mineral additions are thus incorporated to partially replace cement, in order to improve the workability of the concrete. These mineral additions necessarily affect the concrete's microstructure and its durability. Therefore, notwithstanding the many well-documented and acknowledged advantages of SCC, a better understanding its behaviour is still required, in particular when its composition includes significant amounts of mineral additions. An ambitious working plan was devised: first, the SCC's microstructure was studied and characterized and afterwards the main transport and degradation mechanisms of the SCC produced were studied and characterized by means of SEM image analysis, chloride migration, electrical resistivity, and carbonation tests. It was then possible to draw conclusions about the SCC's durability. The properties studied are strongly affected by the type and content of the additions. Also, the use of ternary mixes proved to be extremely favourable, confirming the expected beneficial effect of the synergy between LF and FA.

Three-dimensional, in-silico breast phantom for multimodality image simulations

We report on the construction of anatomically realistic three-dimensional in-silico breast phantoms with adjustable sizes, shapes and morphologic features. The concept of multiscale spatial resolution is implemented for generating breast tissue images from multiple modalities. Breast epidermal boundary and subcutaneous fat layer is generated by fitting an ellipsoid and 2nd degree polynomials to reconstructive surgical data and ultrasound imaging data. Intraglandular fat is simulated by randomly distributing and orienting adipose ellipsoids within a fibrous region immediately within the dermal layer. Cooper’s ligaments are simulated as fibrous ellipsoidal shells distributed within the subcutaneous fat layer. Individual ductal lobes are simulated following a random binary tree model which is generated based upon probabilistic branching conditions described by ramification matrices, as originally proposed by Bakic et al [3, 4]. The complete ductal structure of the breast is simulated from multiple lobes that extend from the base of the nipple and branch towards the chest wall. As lobe branching progresses, branches are reduced in height and radius and terminal branches are capped with spherical lobular clusters. Biophysical parameters are mapped onto the complete anatomical model and synthetic multimodal images (Mammography, Ultrasound, CT) are generated for phantoms of different adipose percentages (40%, 50%, 60%, and 70%) and are analytically compared with clinical examples. Results demonstrate that the in-silico breast phantom has applications in imaging performance evaluation and, specifically, great utility for solving image registration issues in multimodality imaging.

Back to Basics: Deriving Representation Changers Functionally

Many functional programs can be viewed as representation changers, that is, as functions that convert abstract values from one concrete representation to another. Examples of such programs include base-converters, binary adders and multipliers, and compilers. In this paper we give a number of different approaches to specifying representation changers (pointwise, functional, and relational), and present a simple technique that can be used to derive functional programs from the specifications.