Long bone panoramas from fluoroscopic X-ray images

This paper presents a new method for creating a single panoramic image of a long bone from several individual fluoroscopic X-ray images. Panoramic images are useful preoperatively for diagnosis, and intraoperatively for long bone fragment alignment, for making anatomical measurements, and for documenting surgical outcomes. Our method composes individual overlapping images into an undistorted panoramic view that is the equivalent of a single X-ray image with a wide field of view. The correlations between the images are established from the graduations of a radiolucent ruler imaged alongside the long bone. Unlike existing methods, ours uses readily available hardware, requires a simple image acquisition protocol with minimal user input, and works with existing fluoroscopic C-arm units without modifications. It is robust and accurate, producing panoramas whose quality and spatial resolution is comparable to that of the individual images. The method has been successfully tested on in vitro and clinical cases.     

Multi-input/single-output computer-aided control design using the quantitative feedback theory

The quantitative feedback theory is an engineering design technique of uncertain feedback systems having robust stability and robust performance specifications. The crux of the quantitative feedback theory is a transformation of robust stability and robust performance specifications into domains in the complex plane, referred to as bounds, where a nominal loop transmission should lie within. To date, a quantitative feedback theory design is being carried out using manual (i.e. graphical) procedures or search algorithms. This paper shows that there exists a formal map from the uncertain plant and each closed-loop specification to these bounds. In particular, it is shown that each map has a closed form consisting of a quadratic inequality. These maps greatly simplify the computational aspects of the quantitative feedback theory in design of single-loop feedback systems. Based on this new development, a simple-to-implement, efficient computer algorithm is outlined.     

Graininess of judgment under uncertainty: An accuracy-informativeness trade-off.

This work concerns judgmental estimation of quantities under uncertainty. The authors suggest that the "graininess" or precision of uncertain judgments involves a trade-off between 2 competing objectives: accuracy and informativeness. Coarse (imprecise) judgments are less informative than finely grained judgments; however, they are likely to be more accurate. This trade-off was examined in 3 studies in which participants ranked judgmental estimates in order of preference. The patterns of preference ranking for judgments support an additive trade-off model of accuracy and informativeness. The authors suggest that this trade-off also characterizes other types of uncertain judgments, such as prediction, categorization, and diagnosis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiclass object classification for real-time video surveillance systems

Object classification in video is an important factor for improving the reliability of various automatic applications in video surveillance systems, as well as a fundamental feature for advanced applications, such as scene understanding. Despite extensive research, existing methods exhibit relatively moderate classification accuracy when tested on a large variety of real-world scenarios, or do not obey the real-time constraints of video surveillance systems. Moreover, their performance is further degraded in multi-class classification problems. We explore multi-class object classification for real-time video surveillance systems and propose an approach for classifying objects in both low and high resolution images (human height varies from a few to tens of pixels) in varied real-world scenarios. Firstly, we present several features that jointly leverage the distinction between various classes. Secondly, we provide a feature-selection procedure based on entropy gain, which screens out superfluous features. Experiments, using various classification techniques, were performed on a large and varied database consisting of ∼29,000 object instances extracted from 140 different real-world indoor and outdoor, near-field and far-field scenes having various camera viewpoints, which capture a large variety of object appearances under real-world environmental conditions. The insight raised from the experiments is threefold: the efficiency of our feature set in discriminating between classes, the performance improvement when using the feature selection method, and the high classification accuracy obtained on our real-time system on both DSP (TMS320C6415-6E3, 600 MHz) and PC (Quad Core Intel® Xeon® E5310, 2 × 4 MB Cache, 1.60 GHz, 1066 MHz) platforms.     

Multi-level graph layout on the GPU

This paper presents a new algorithm for force directed graph layout on the GPU. The algorithm, whose goal is to compute layouts accurately and quickly, has two contributions. The first contribution is proposing a general multi-level scheme, which is based on spectral partitioning. The second contribution is computing the layout on the GPU. Since the GPU requires a data parallel programming model, the challenge is devising a mapping of a naturally unstructured graph into a well-partitioned structured one. This is done by computing a balanced partitioning of a general graph. This algorithm provides a general multi-level scheme, which has the potential to be used not only for computation on the GPU, but also on emerging multi-core architectures. The algorithm manages to compute high quality layouts of large graphs in a fraction of the time required by existing algorithms of similar quality. An application for visualization of the topologies of ISP (Internet Service Provider) networks is presented.     

Suspension‐deposited carbon‐nanotube networks for flexible active‐matrix displays

Abstract— The unique properties of carbon nanotubes (CNTs) promise innovative solutions for a variety of display applications. The CNTs can be deposited from suspension. These simple and low‐cost techniques will replace time‐consuming and costly vacuum processes and can be applied to large‐area glass and flexible substrates. Single‐walled carbon nanotubes (SWNTs) have been used as conducting and transparent layers, replacing the brittle ITO, and as the semiconducting layer in thin‐film transistors (TFTs). There is no need for alignment because a CNT network is used instead of single CNTs. Both processes can be applied to glass and to flexible plastic substrates. The transparent and conductive nanotube layers can be produced with a sheet resistance of 400 Ω/□ at 80% transmittance. Such layers have been used to produce directly addressed liquid‐crystal displays and organic light‐emitting diodes (OLED). The CNT‐TFTs reach on/off ratios of more than 10⁵ and effective charge‐carrier mobilities of 1 cm²/V‐sec and above.     

Concurrent Java Test Generation as a Search Problem

A Random test generator generates executable tests together with their expected results. In the form of a noise-maker, it seeds the program with conditional scheduling primitives (such as yield()) that may cause context switches. As a result different interleavings are potentially produced in different executions of the program. Determining a-priori the set of seeded locations required for a bug to manifest itself is rarely possible.This work proposes to reformulate random test generation of concurrent Java programs as a search problem. Hence, it allows applying a set of well known search techniques from the domain of AI to the input space of the test generator. By iteratively refining the input parameters fed to the test generator, the search process creates testing scenarios (i.e. interleavings) that maximizes predefined objective functions. We develop geneticFinder, a noise-maker that uses a genetic algorithm as a search method. We demonstrate our approach by maximizing two objective functions: the high manifestation rate of concurrent bugs and the exporting of a high degree of debugging information to the user. Experimental results show our approach is effective.