nils-herrmann/clean_scirepeval huggingface dataset:
Detecting heart wall boundaries by tracking features in an echocardiogram sequence

An approach to extracting information from an echocardiogram sequence to the endocardial boundary as the heart undergoes deformation in a cardiac cycle is presented. Image velocities used as attributes of the edge segments are estimated by the image-flow approach, which relates the spatial intensity gradient to the temporal gradient. One component of the velocity can be directly computed, whereas the other must be recovered from other information. An algorithm based on the total-least-squares method is used to recover the lost components. Experimental results using an acquired echocardiographic image sequence are presented. Since the motion pattern in the image sequence is quite complicated, it is difficult to judge the results. The diastole effect is not apparent; however, the indicated velocities do not agree with the intensity variations.<<ETX>>
Dynamic trajectory planning for robotic knot tying

Knot tying is an important component of surgery. When surgeons perform such operation via a tele-operated robotic system, the limited dexterity and field-of-view often poses technical challenges to the surgeons. In this paper, a new knot-tying method is proposed to enhance the quality of robotic knot-tying practice with low supervision. The trajectories of the instruments that can maintain the suture tension during the loop winding were formulated through the developed equations and MATLAB was employed to simulate the trajectory profiles. The grippers of the two instruments were then manipulated to grasp the suture and dynamically follow the pre-defined trajectories so that a suture knot can be constructed. Experiments were conducted and the results confirm that suture loops can be successfully winded around the instrument without suture slippage.
Illumination correction in digital images

Illumination in an image often needs to be corrected or adjusted for several reasons. Recognition of images, such as those of faces, that are based on image data as patterns depends on having the lighting direction of the query image and that of the database images be aligned. In computational video, acquired images are often texture mapped to blend with computer generated polygonal surfaces. The shading of a polygonal surfaces changes as the light source direction relative to the composite object changes due, for instance, to the object's motion. We experiment with methods that can adjust the texture mapped image according to the illumination change. We test our concept on images of human faces
Detecting left ventricular endocardial and epicardial boundaries by digital two-dimensional echocardiography.

Cardiac function is evaluated using echocardiographic analysis of shape attributes, such as the heart wall thickness or the shape change of the heart wall boundaries. This requires that the complete boundaries of the heart wall be detected from a sequence of two-dimensional ultrasonic images of the heart. The image segmentation process is made difficult since these images are plagued by poor intensity contrast and dropouts caused by the intrinsic limitations of the image formation process. Current studies often require having trained operators manually trace the heart walls. A review of previous work is presented, along with how this problem can be viewed in the context of the computer vision area. A novel algorithm is presented for detecting the boundaries. This algorithm first detects spatially significant features based on the measurement of image intensity variations. Since the detection step suffers from false alarms and missing boundary points, further processing uses high-level knowledge about the heart wall to label the detected features for noise rejection and to fill in the missing points by interpolation.
Modeling and development of a magnetically actuated system for micro-particle manipulation

This paper presents the modeling and development of a micromanipulation system that can provide continuous force to manipulate a micro-particle through an externally applied magnetic field. This system consists of six electromagnetic coils and the size of the micro-particle to be manipulated is less than 30μm. The magnetic field maps generated from the electromagnets are first simulated using a finite element method. Based on the result, we then calculate the force that can be provided by the system. A prototype of the system is designed and constructed, which is used to precisely control the navigation of a super-paramagnetic micro-bead in a microfluidic environment. This system can be used for drug delivery as well as medical applications such as minimally invasive surgery, diagnosis and sensing.
Dielectrophoresis-induced cell patterning using a new PLA scaffold made by 3D printing

This paper presents a new technique of fabricating 3D-printed scaffolds that can utilizes dielectrophoresis (DEP) for cell patterning. The scaffold was first fabricated using a 3D printer with a biodegradable polymer, polylactic acid (PLA). The electrical conductivity of the polymeric scaffold was enhanced through sputtering a thin layer of gold. When a voltage was supplied to the scaffold, non-uniform electric fields were generated so that cells were polarized and patterned onto the scaffold. Experiments were conducted to demonstrate that the gold-coated PLA scaffold could be used for rapid patterning MC3T3-E1 cells via DEP. Cell proliferation was assessed by (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) MTT method and the result confirms the DEP cell patterning mechanism is not cytotoxic.
Multiresolution superpixels for visual saliency detection

Salient regions are those that stand out from others in an image. We present an algorithm to detect salient regions in an image that is represented as superpixels at a number of resolutions. Superpixels are segments generated by oversegmenting an image and they form a perceptually meaningful representation that preserves the underlying image structure. The novelty of our method is the ranking of a superpixel by its dissimilarities with respect to other superpixels and highlighting the statistically salient region proportional to their rank. This is based on the premise that salient region group together and they stand out. We tested our method using standard data sets containing images of varied complexity and compared the results to ground truth data. Our results show that our saliency detection algorithm is robust to changes in color, object size, object location in image and background type.
One-Dimensional Mapping for Estimating Projective Transformations

In this paper, the 1-D mapping is studied for estimating a general projective transformation between images. First, a ray model of image patches is proposed to convert a complex projective deformation of a patch in the Cartesian space into two simple rigid shifts of radial lines in the log-polar/inverse-polar space. To capture these shifts via direct search, two types of radial image line matching, viz. 1-D log-polar mapping and 1-D inverse-polar mapping, are formally defined. Also, the unique features of these shifts are analyzed. Then, a novel two-step mathematical framework is devised for transformation estimation. In the first step, the 1-D log-polar mapping is applied to estimating four affine parameters via two alternative methods for simulated/real images. In the second step, the 1-D inverse-polar mapping is applied to estimating two projective parameters. By a direct search combined with the two-step line matching, two translational parameters are also determined. Finally, the performance of the framework is evaluated first in estimating a variety of projective transformations by comparing the estimates with their ground truths and between the two proposed methods, and second in registering a wide range of challenging image pairs by comparing with a state-of-the-art feature-based method.
Pressure surge reflector for pipe type cable system

The development and testing of a pressure surge reflector designed to reduce the pressure seen at potheads during an electrical failure in a pipe-type cable system are described. The reflector is designed to protect the potheads from failing because of a pressure surge that may be large enough to fracture the porcelain, particularly when the electrical failure is physically close to the pothead. Tests indicate that the gaskets in the pothead-base-riser pipe flanges will rupture and leak dielectric fluid at a pressure surge of 900-1200 psi when the bolts are torqued to specified values. Destruction of the high-strength pothead design may first occur in the range of 1600-1800 psi. Therefore, it is possible that an electrical failure in the cable pipe in close proximity to the cable end will initiate leaks of dielectric fluid at the gaskets rather than destroy the pothead. The prototype reflector lowers the pressure significantly, bringing the pressure surge below the factory pressure test level for standard potheads.
Fabrication of a microcoil through parallel microassembly

This paper presents the fabrication of a three-dimensional microcoil through the technique of microassembly. The microcoil design is comprised of nine out-of-plane micro-sized windings. Each winding was assembled onto the base substrate orthogonally by a robotic manipulator through microassembly. In contrast to the conventional serial pick-and-place microassembly, this work incorporated the approach of parallel microassembly to grasp and assemble three windings onto the base substrate simultaneously for increased productivity. In addition, a vision-based algorithm was developed to automate the parallel grasping process of three windings. This algorithm utilized well-defined templates to provide high-precision position and orientation evaluations for the micro-sized components. The performance of the microcoil fabrication process was evaluated and discussed. To establish better electrical contact between the windings and the base substrate, conductive adhesive was introduced in the assembly process and the electrical properties of the assembled microcoil structure were examined.
Development of a digital video system for remote sensing of coasts

The proliferation of low-cost multispectral CCD video technology in combination with the Global Positioning System (GPS) has progressed to the point where quantifiable and meaningful results can be derived from low-altitude aerial digital video systems. This low-cost technology will provide meaningful and sometimes critical data that will be required for regional and site-specific land and emergency management. Historically, video has not had the resolution or repeatability to be used for spatial processing, but newer digital systems have expanded the capabilities. Potential applications include the areas of precision farming, oil-spill clean-up, fire remediation and corridor mapping. In this article, we explain how we developed a low-altitude digital video system and compared it to a number of commercially available remote sensing platforms. Salient information such as color, texture, shape and orientation can be extracted from the images and used in a geographic information system for landscape and site-specific analysis.
Development of ±400 KV/±High and Medium-Pressure Oil-Filled Paper Insulated DC Power Cable System

This paper describes the steps to be taken to optimize the design of oil-paper insulated power cable for high voltage dc operation. Experimental data is presented on models to establish the steady-state dc dielectric strength and the switching surge polarity reversal dielectric strength of oil-paper insulations. Laboratory data is presented on factory made prototype cables tested under voltage stress conditions applicable to a ±600 kV dc system. Optimized designs of high-pressure oil-filled pipe-type and medium-pressure oil-filled self-contained cables are presented.
A nonlinear multiresolution approach to echocardiographic image segmentation

The application of multiresolution nonlinear window operators to echocardiographic image segmentation is studied. A method that can potentially reduce the signal-to-noise ratio loss in the data is to digitize the line-mode data directly. An approach that is more stable than using finite difference operators is to compare and correlate different beams of the line-mode fan-beam data. Nonlinear operators such as median filtering and morphological operators are used. These operators are known to not displace the edges in the data while having robust performance in noise suppression. After applying an operator of a specific size, the data sequence can be segmented into different regions. By using such an operator with different sizes, the amount of detail can be reduced successively, to the point where only the major components, such as the inner heart chamber, remain and are identified. The endocardial boundary is thus detected based on the edge points found on each beam.<<ETX>>
Automated assembly of biological cells in a 3D scaffold via dielectrophoresis manipulation

Patterning and assembly of biological cells in a 3D structure represents an important process in artificial tissue engineering. This paper presents the design of a multi-layer electrode scaffold used to assemble biological cells into a 3D pattern. Through suppling voltage to the multi-layer scaffold, three-dimensional electric fields can be established to manipulate cells towards the scaffold via dielectrophoresis (DEP). To fabricate such a 3D scaffold, we utilized the laser cutting technology to cut stainless steel into a precision structure with integrated micro-tips. Layers of the structure were then stacked together forming the 3D scaffold. Experiments were conducted and the scaffold was able to generate the DEP force and assemble biological cells at the desired positions with required patterning.
Rule extraction from neural networks using fuzzy sets

We present an algorithm for extracting if-then rules from a neural network using fuzzy sets. A set of crisp rules each of which is associated with a certainty factor is initially extracted from a trained neural network. The extraction process is based on fuzzy sets. The crisp rules often induce ambiguity areas in the decision space. The certainty factors of the ambiguity areas are transformed into fuzzy sets. A set of rules with confidence values in natural language terms are then extracted. Experiments using the Iris and the Wisconsin breast cancer databases are used to demonstrate the performance of the method.
Parallel optimization of stack filters

An open problem associated with designing stack filters is finding the optimum configuration for a given noise type and the signal characteristics which need to be preserved. This problem is modeled here as a combinatorial search problem. Efficient search methods that can be easily implemented on any massively parallel computer were developed and tested in two parallel computing environments. The first is the Connection Machine, and the second is a hypercube-connected MIMD (multiple-instruction-stream, multiple-data-stream) machine simulated using Cosmic C. The performance of the filters found by the algorithms developed were excellent in comparison with the performance of the median filter. The efficiency of the algorithms clearly demonstrates the potential of using them for adaptive filtering. The algorithms can be implemented on any type of parallel computer.<<ETX>>
Dielectrophoresis-based automatic 3D cell manipulation and patterning through a micro-electrode integrated multi-layer scaffold

Automatic manipulation and patterning of biological cells into an artificial scaffold is an imperative step in the production of high-quality tissue for tissue transplantation. This paper examines the incorporation of dielectrophoresis into a three-dimensional (3D) scaffold body for batch manipulation and patterning of cells. To facilitate dielectrophoresis-based manipulation, a multi-layer biocompatible scaffold structure utilizing its body as the integrated micro-electrodes was designed and fabricated using soft lithography. Voltage of opposite polarity was applied to the scaffold structure and the resultant electric field from the scaffold body polarized the cells in the culture medium and attracted them to migrate towards the scaffold body. Experiments were conducted and the results confirm that the proposed multi-layer scaffold is capable of generating dielectrophoretic forces to manipulate the cells to the scaffold surface, forming a three-dimensional cellular pattern automatically.
Inverse-polar ray projection for recovering projective transformations

A ray projection in the inverse-polar space is proposed for recovering a projective transformation between two segmented images. The images are converted from their original Cartesian space to the inverse-polar space. Then, the two ray projections - one shift-invariant and the other shift-sensitive - of the inverse-polar images are computed to create two sets of data. Based on the obtained projection data, a two-step strategy is employed to recover the projective transformation. In the first step, the shift-invariant data are used to recover the four affine parameters. In the second step, the shift-sensitive data are used to recover the two projective parameters. The remaining two translation-related parameters are recovered in, e.g., an exhaustive search combined with the two-step recovery strategy. The proposed approach has been tested successfully to recover a variety of projective transformations between real images.
An Efficient Vanishing Point Detection by Clustering on the Normalized Unit Sphere

Detecting vanishing points in digital images is important for 3D reconstruction of a scene using uncalibrated cameras. We present a new vanishing point detection algorithm based on the normalized unit sphere that not only bounds the search space but treats the finite vanishing points and the vanishing points at infinity in the same manner. The experimental results using synthetic and real data demonstrate the efficacy and performance of this algorithm.
Quantitative analysis of chemoattractant gradient induced cell migration velocity and automatic controller design

Cell chemotaxis is a phenomenon in which cells spatially sense the chemoattractant gradient in the extra-environment and move along this gradient. This paper illustrates the relationship between the chemoattractant gradient and the cell velocity quantitatively, using a single-cell motility assay method based on optically manipulated microsources. A case study was performed on leukemia cancer cells. Quantitative study indicates that the cell is sensitive to the gradient, and can move faster under a high gradient. Based on the quantitative relationship, a control strategy was proposed to realize automatically induced cell migration. The simulation results demonstrate the effectiveness and robustness of the proposed method.
Time-series data prediction based on reconstruction of missing samples and selective ensembling of FIR neural networks

This paper considers the problem of time-series forecasting by a selective ensemble neural network when the input data are incomplete. Five fill-in methods, viz. cubic smoothing spline interpolation, EM (Expectation maximization), regularized EM, average EM, and average regularized EM, are simultaneously employed in a first step for reconstructing the missing values of time-series data. A set of complete data from each individual fill-in method is used to train a finite impulse response (FIR) neural network to predict the time series. The outputs from individual network are combined by a selective ensemble method in the second step. Experimental results show that the prediction made by the proposed method is more accurate than those predicted by neural networks without a fill-in process or by a single fill-in process.
Ray Projection for Recovering Projective Transformations and Illumination Changes

The ray projection and its application to recovering a projective geometric transformation and an affine lighting change between two objects are mathematically studied. A novel technique, viz., variable contour, is proposed for accurately evaluating the ray projection. Moreover, a novel flexible framework of the ray projection is devised for the joint recovery of the eight parameters for the projective transformation and the two parameters for the lighting change. Finally, the framework is experimentally evaluated by recovering a variety of geometric and photometric transformations between real images of indoor and outdoor scenes. Its robustness to image blur and occlusion is demonstrated. Its versatility is illustrated through matching different objects in different classes.
A spatial summation model for image processing by artificial neural networks

The representation of the data used in a computational algorithm should be coupled to the computing machine on which the algorithm is implemented. A model for representing image data for gray-level image processing by artificial neural networks is presented. An input layer converts an image with real-valued or quantized intensities to a binary representation. The input layer uses threshold logic as the activation rule. An image processing task is decomposed into a collection of massively parallel decision tasks, each of which is performed locally by a hidden processing unit. The output of the hidden layer, in binary form, can be converted to a resultant image with real-valued intensities by the output layer. An advantage of this approach is that it is well-matched to the decision and classification capabilities of neural networks. A noise-suppressing algorithm with robust performance is implemented to illustrate the efficacy of this model
3D cell manipulation with honeycomb-patterned scaffold for regeneration of bone-like tissues

Dielectrophoresis (DEP) has widely been used for manipulation and patterning of biological cells. In this paper, a novel multi-layer scaffold structure was designed for patterning cells in 3D via dielectrophoresis. Honeycomb patterns were integrated in each layer of the structure in order to pattern cells into bone-like tissues. When a voltage was supplied to the scaffold structure, non-uniform electric fields were established to manipulate cells automatically, forming honeycomb-shaped patterns at different layers. To confirm the proposed cell manipulation mechanism, the electric fields were simulated and the structure was examined through experiments. Different voltage inputs were tested and a voltage input of 20V can form a uniform and complete hexagon patterns. The results show that this novel 3D scaffold is able to manipulate biological cells in 3D via dielectrophoresis rapidly.
One-Dimensional Mappings for Recovering Large Scale Projective Transformations

One-dimensional mappings in the log-polar and in the inverse-polar spaces are proposed. Based on these mappings, a two-step search strategy has been developed to recover the eight parameters of a general projective transformation between two image patches. First, the four affine parameters are recovered using the one-dimensional log-polar mapping. Secondly, the two projective parameters are recovered using the one-dimensional inverse-polar mapping. At each step the recovery is done by mapping only two line pairs. The remaining two translational parameters are determined by applying these two mappings to an exhaustive search. The proposed mapping strategy has successfully been used to recover different two-dimensional transformations between real images.
Quasi-morphism and comprehensibility of rules in inductive learning

We present a model of creating a hierarchical set of rules that encode generalizations and exceptions derived from induction learning. The rules use the input features directly and are therefore comprehensible to the users. Learning is performed by a feedforward neural network and the rules are extracted from the trained network. A pattern classification task is used to demonstrate the efficacy of our approach. We show that the rules have similar classification performance while being more comprehensible to the users.