waashk/dblp huggingface dataset:
3d reconstruction of a femoral shape using a parametric model and two 2d fluoroscopic images. in medical diagnostic imaging, the x-ray ct scanner and the mri system have been widely used to examine 3d shapes and internal structures of living organisms and bones. however, these apparatuses are generally large and very expensive. since an appointment is also required before examination, these systems are not suitable for urgent fracture diagnosis in emergency treatment. however, x-ray/fluoroscopy has been widely used as traditional medical diagnosis. therefore, the realization of the reconstruction of precise 3d shapes of living organisms or bones from a few conventional 2d fluoroscopic images might be very useful in practice, in terms of cost, labor, and radiation exposure. the present paper proposes a method by which to estimate a patient-specific 3d shape of a femur from only two fluoroscopic images using a parametric femoral model. first, we develop a parametric femoral model by the statistical analysis of 3d femoral shapes created from ct images of 56 patients. then, the position and shape parameters of the parametric model are estimated from two 2d fluoroscopic images using a distance map constructed by the level set method. experiments using synthesized images, fluoroscopic images of a phantom femur, and in vivo images for hip prosthesis patients are successfully carried out, and it is verified that the proposed system has practical applications.
crowds of moving objects: navigation planning and simulation. this paper presents a solution to interactive navigation planning and real-time simulation of a very large number of entities moving in a virtual environment. from the environment geometry analysis, we deduce a structure called navigation graph, which is the base to our method. after the description of this structure, we introduce a set of algorithms dedicated to answer navigation queries with a set of various solution paths and to execute the planned navigation in an efficient manner. we equally demonstrate method performance and robustness over several examples.
safe planning for human-robot interaction. this paper presents a strategy for improving the safety of human-robot interaction by minimizing a danger criterion during the planning stage. this strategy is one part of the overall methodology for safe planning and control in human-robot interaction. the focus application is a hand-off task between an articulated robot and an inexpert human user. two formulations of the danger criterion are proposed: a criterion assuming independent safety-related factors, and a criterion assuming mutually dependent factors. simulations of the proposed planning strategy are presented for both 2d and 3d robots. the results indicate that a criterion based on scaled mutually dependent factors such as the robot inertia and the human robot distance generates safe, feasible paths for interaction. &copy; 2005 wiley periodicals, inc.
temporal range registration for unmanned ground and aerial vehicles. an iterative temporal registration algorithm is presented in this article for registering 3d range images obtained from unmanned ground and aerial vehicles traversing unstructured environments. we are primarily motivated by the development of 3d registration algorithms to overcome both the unavailability and unreliability of global positioning system (gps) within required accuracy bounds for unmanned ground vehicle (ugv) navigation. after suitable modifications to the well-known iterative closest point (icp) algorithm, the modified algorithm is shown to be robust to outliers and false matches during the registration of successive range images obtained from a scanning laser detection and ranging (ladar) rangefinder on the ugv. towards registering ladar images from the ugv with those from an unmanned aerial vehicle (uav) that flies over the terrain being traversed, we then propose a hybrid registration approach. in this approach to air to ground registration to estimate and update the position of the ugv, we register range data from two ladars by combining a feature-based method with the aforementioned modified icp algorithm. registration of range data guarantees an estimate of the vehicle's position even when only one of the vehicles has gps information. temporal range registration enables position information to be continually maintained even when both vehicles can no longer maintain gps contact. we present results of the registration algorithm in rugged terrain and urban environments using real field data acquired from two different ladars on the ugv.
general solution for the dynamic modeling of parallel robots. in this paper, we present a general method to calculate the inverse and direct dynamic models of parallel robots. the models are expressed in a closed form by a single equation in which all the elements needed are expressed. the solution is given in terms of the dynamic models of the legs, the dynamics of the platform and some jacobian matrices. the proposed method is applied in this paper on two parallel robots with different structures.
improving perception in time delayed teleoperation. telerobotics has long struggled to provide realistic force feedback to a user, especially across substantial time delays. wave variable based controllers provide stable force reflection at frequencies up to a few hertz for typical communication delays; however, the bandwidth of human perception extends to a thousand hertz. in this paper we aim to improve the user's perception by constructing a fundamentally asymmetric controller that better matches the sensory capabilities of the human operator. the improvements stem from two extensions to a normal wave variable controller. first, we revisit wave reflections and utilize wave filtering and shaping to separate distracting oscillations from useful reaction information. this avoids excess damping inherent to impedance matching and enhances the low-frequency feel of the system. secondly, we incorporate high-frequency feedback from a force sensor located at the slave end-effector. this augmented system leverages the passivation capabilities of wave filters to compensate for energy generation. it renders the complete spectrum of environment interaction forces to the user, allowing the perception of small environment features across substantial delays. these improvements are tested and validated in three simple experiments on a three-degrees-of-freedom testbed.
minimum wheel-rotation paths for differential-drive mobile robots. the shortest paths for a mobile robot are a fundamental property of the mechanism, and may also be used as a family of primitives for motion planning in the presence of obstacles. this paper characterizes shortest paths for differential-drive mobile robots, with the goal of classifying solutions in the spirit of dubins curves and reeds-shepp curves for car-like robots. to obtain a well-defined notion of shortest, the total amount of wheel-rotation is optimized. using the pontryagin maximum principle and other tools, we derive the set of optimal paths, and we give a representation of the extremals in the form of finite automata. it turns out that minimum time for the reeds-shepp car is equal to minimum wheel-rotation for the differential-drive, and minimum time curves for the convexified reeds-shepp car are exactly the same as minimum wheel-rotation paths for the differential-drive. it is currently unknown whether there is a simpler proof for this fact.
error-driven active learning in growing radial basis function networks for early robot learning. in this paper, we describe a new error-driven active learning approach to self-growing radial basis function networks for early robot learning. there are several mappings that need to be set up for an autonomous robot system for sensorimotor coordination and transformation of sensory information from one modality to another, and these mappings are usually highly nonlinear. traditional passive learning approaches usually cause both large mapping errors and nonuniform mapping error distribution compared to active learning. a hierarchical clustering technique is introduced to group large mapping errors and these error clusters drive the system to actively explore details of these clusters. higher level local growing radial basis function subnetworks are used to approximate the residual errors from previous mapping levels. plastic radial basis function networks construct the substrate of the learning system and a simplified node-decoupled extended kalman filter algorithm is presented to train these radial basis function networks. experimental results are given to compare the performance among active learning with hierarchical adaptive rbf networks, passive learning with adaptive rbf networks and hierarchical mixtures of experts, as well as their robustness under noise conditions.
on the design of traps for feeding 3d parts on vibratory tracks. in the context of automated feeding (orienting) of industrial parts, we study the algorithmic design of traps in the bowl feeder track that filter out all but one orientation of a given polyhedral part. we propose a new class of traps that removes a v-shaped portion of the track. the proposed work advances the state-of-the-art in algorithmic trap design by extending earlier work1,6,17—which focuses solely on 2d parts—to 3d parts, and by incorporating a more realistic part motion model in the design algorithm. we exploit the geometric structure of the design problem and build on concepts and techniques from computational geometry to obtain an efficient algorithm that reports the complete set of valid traps.
stability analysis for prioritized closed-loop inverse kinematic algorithms for redundant robotic systems. stability analysis of priority-based kinematic control algorithms for redundant robotic systems is approached in this paper. starting from the classical applications in position control of manipulators, the kinematic-based approaches have lately been applied to, e.g., visual servoing and quadruped or multirobot coordination control. a common approach consists in the definition of several tasks properly combined in priority. in this paper, by resorting to a lyapunov-based stability discussion for several prioritized inverse kinematics algorithms, sufficient conditions for the control gains and the tasks' design are given for the regulation problem. two case studies show the practical implementation of the results.
robot assisted real-time tumor manipulation for breast biopsy. breast biopsy guided by imaging techniques such as ultrasound is widely used to evaluate suspicious masses within the breast. the current procedure allows the clinician to determine the location and extent of a tumor in the patient breast before inserting the needle. however, there are several problems with this procedure: the complex interaction dynamics between the needle force and the breast tissue will likely displace the tumor from its original position, necessitating multiple insertions, causing clinicians' fatigue, patient's discomfort, and compromising the integrity of the tissue specimen. in this paper, we present a new concept for real-time manipulation of a tumor using a robotic controller that monitors the image of the tumor to generate appropriate external force to position the tumor at a desired location. the idea here is to demonstrate that it is possible to manipulate a tumor in real time by applying controlled external force in an automated way such that the tumor does not deviate from the path of the needle. experiments on breast phantoms are presented to demonstrate the essence of this concept. the success of this approach has the potential to reduce the number of attempts a clinician makes to capture the desired tissue specimen, minimize tissue damage, improve speed of biopsy, reduce patient discomfort, and eliminate false negative results.
insertable surgical imaging device with pan, tilt, zoom, and lighting. in this paper we describe work we have done in developing an insertable surgical imaging device with multiple degrees of freedom for minimally invasive surgery. the device is fully insertable into the abdomen using standard 12 mm trocars. it consists of a modular camera and lens system which has pan and tilt capability provided by two small dc servo motors. it also has its own integrated lighting system that is part of the camera assembly. once the camera is inserted into the abdomen, the insertion port is available for additional tooling, motivating the idea of single-port surgery. a third zoom axis has been designed for the camera as well, allowing close-up and far-away imaging of surgical sites with a single camera unit. in animal tests with the device we have performed surgical procedures including cholecystectomy, appendectomy, running (measuring) the bowel, suturing, and nephrectomy. preliminary tests suggest that the new device may have advantages over a standard laparoscope including the following. â¢ low-cost and simple design. â¢ easier and more intuitive to use than a standard laparoscope. â¢ joystick operation requires no specialized operator training. â¢ pan/tilt functions provide a large imaging volume not restricted by the fulcrum point of standard laparoscope. â¢ time to perform procedures was better than or equivalent to a standard laparoscope. we believe these insertable platforms will be an integral part of future surgical systems. the platforms can be used with tooling as well as imaging devices, allowing many surgical procedures to be performed using such a system.
baseball seasons and dog years. from 1995 through 1997, instant sports used the internet to provide interactive real-time coverage of major league baseball. the changes in instant sports core architecture during that time provide some lessons about architectural evolution in the context of rapidly changing technology, including the need to identify fundamental issues rather than trendy ones, the importance of a good domain model, and the role of domain characteristics in balancing computational and communication resources.
an automatic programming system to support an experimental science. programs are often used in experimental sciences to test new models and theories against real-world data. one of the major bottlenecks in that process is the need to write the program which implements the new model. &oslash;0 is an automatic programming system which supports petroleum scientists in testing quantitative log interpretation models against log data from oil wells. the user (a petroleum scientist) describes a model by interacting with &oslash;0 in the natural terms of the domain. &oslash;0 then automatically writes a program which implements the model. the entire process takes from ten to twenty minutes and achieves results which previously required two to three weeks of effort.
observations on the interaction between coding and efficiency knowledge in the psi program synthesis system. this paper discusses how the synthesis phase of the psi system constructs programs from high level program models by using coding knowledge and efficiency knowledge. in our preliminary implementation, these knowledge bases are separated into distinct modules, the coding expert and the efficiency expert. we describe how the coding expert uses rule-based programming knowledge to produce alternative algorithm and data structure choices, and how the efficiency expert selects the best choice by estimating the costs of the alternatives using analysis of algorithm techniques. communication between the modules centers around descriptions of partially developed programs which are produced by the coding expert and analyzed by the efficiency expert. our system has implemented several small programs. from our experience with these modules, we conclude that there is a strong interaction between coding and efficiency knowledge which necessitates a corresponding complexity in the communication mechanism.
the stream machine: a data flow architecture for real-time applications. the stream machine is a software architecture designed to support the development and evolution, as well as the efficient execution, of software that performs both data acquisition and process control under real-time constraints. a stream machine program consists of a set of concurrently executing modules communicating through streams of data. streams provide essentially a data flow style of communication, thereby supporting deterministic data acquisition and calculation. the basic constructs have been augmented by several time-based operations to support process control software. in addition, explicit declarations of timing constraints layered on stream machine programs are currently being explored for resource allocation and scheduling. our experience to date with two implementations of the stream machine suggests that it facilitates the mixture of software that performs both data acquisition and process control.
the dimensions of healthy maintenance. what characterizes &ldquo;healthy&rdquo; or &ldquo;satisfactory&rdquo; software maintenance? how can we know it when we see it? this paper gives initial answers to these questions. we first argue the need for objectively measurable maintenance performance criteria in judging the &ldquo;adequacy&rdquo; of maintenance and present a set of criteria for judging maintenance performance in a particular software environment. we then subject the criteria to a practical test by applying them in this environment. we show how applying the criteria enables an informed overall maintenance performance appraisal, locates general maintenance problems, stimulates suggestions for improving maintenance on individual projects, allows these projects' maintenance to be compared and the projects ordered for improvement, and assesses the potential effectiveness of the suggestions in new project maintenance. we also sketch how criteria application can be generalized to software development monitoring and design methodology evaluation.
a flexible environment for program development based on a symbolic interpreter. the paper describes an interactive programming system which provides an integrated collection of tools for dealing with the whole process of program development. the pivot tool, the symbolic interpreter, may cover a broad range of applications, from testing to correctness proving. the aspects in which the symbolic interpreter differs from a conventional interpreter, i.e. the possibility of handling nondeterministic branching at choice points and the presence of a system for manipulating symbolic expressions, are described. furthermore, the main features of a programming language, around which the programming system is built, are presented.
facts and myths affecting software reuse. discusses the three most important facts or myths affecting reuse. there is a great deal of misunderstanding about reuse in the software domain and it is difficult to pick out only three: there has been to much emphasis on the reuse of code; software reuse implies some form of modification of the artifact being reused; and software development processes do not explicitly support reuse, in fact they implicitly inhibit reuse
a compliance notation for verifying concurrent systems. the compliance notation provides a practical system where both formal and informal techniques can be employed in software verification. the notation has been successfully applied in verifying some industrial safety-critical systems, but currently it has no support for verifying concurrent systems. this research aims to extend the compliance notation with appropriate support for verifying concurrent systems.
estimation of project success using bayesian classifier. the software projects are considered to be successful if the cost and the duration are within the estimated ones and the quality is satisfactory. to attain project success, the project management, in which the final status of project is estimated, must be incorporated.in this paper, we consider estimation of the final status(that is, successful or unsuccessful) of project by applying bayesian classifier to metrics data collected from project. in order to attain high estimation accuracy rate, we must select only a set of appropriate metrics to be applied. here we consider two selection methods: the first method by the experts and the second method by the statistical test.then we conducted an experiment using 28 project data and 29 metrics data in an organization of a certain company. the result showed that the method by the test gave higher accuracy rates than the method by the experts, and bayesian classifier with the test method is effective to estimate project success.
using version control data to evaluate the impact of software tools. software tools can improve the quality and maintainability of software, but are expensive to acquire, deploy and maintain, especially in large organizations. we explore how to quantify the effects of a software tool once it has been deployed in a development environment. we present a simple methodology for tool evaluation that correlates tool usage statistics with estimates of developer effort, as derived from a project's change history (version control system). our work complements controlled experiments on software tools, which usually take place outside the industrial setting, and tool assessment studies that predict the impact of software tools before deployment. our analysis is inexpensive, non-intrusive and can be applied to an entire software project in its actual setting. a key part of our analysis is how to control confounding variables such as developer work-style and experience in order accurately to quantify the impact of a tool on developer effort. we demonstrate our method in a case study of a software tool called ve, a version-sensitive editor used in belllabs. ve aids software developers in coping with the rampant use of preprocessor directives (such as if/ endif) in c source files. our analysis found that developers were approximately 36% more productive when using ve than when using standard text editors.
an analysis of software project failure. the main aim of this paper is to indicate how various losses may be reduced or avoided when the development of software does not proceed according to its schedule; i.e., if what we call &ldquo;bankruptcy&rdquo; occurs. data were collected from twenty three projects in various types of applications, the projects together containing a million lines of code. the causes of failure in developing software were obtained by interviewing the managers of the projects under observation. having analysed these two aspects, this paper points out under what circumstances managers are likely to fail and proposes a method of detecting failures in the software development.
automating bug report assignment. open-source development projects typically support an open bug repository to which both developers and users can report bugs. a report that appears in this repository must be triaged to determine if the report is one which requires attention and if it is, which developer will be assigned the responsibility of resolving the report. large open-source developments are burdened by the rate at which new bug reports appear in the bug repository. the thesis of this work is that the task of triage can be eased by using a semi-automated approach to assign bug reports to developers. the approach consists of constructing a recommender for bug assignments; examined are both a range of algorithms that can be used and the various kinds of information provided to the algorithms. the proposed work seeks to determine through human experimentation a sufficient level of precision for the recommendations, and to analytically determine the trade-offs of the various algorithmic and information choices.