Elastic roadmaps—motion generation for autonomous mobile manipulation

The autonomous execution of mobile manipulation tasks in unstructured, dynamic environments requires the consideration of various motion constraints. The task itself imposes constraints, of course, but so do the kinematic and dynamic limitations of the manipulator, unpredictably moving obstacles, and the global connectivity of the workspace. All of these constraints need to be updated continuously in response to sensor feedback. We present the elastic roadmap framework, a novel feedback motion planning approach capable of satisfying all of these motion constraints and their respective feedback requirements. This framework is validated in simulation and real-world experiments using a mobile manipulation platform and a stationary manipulator.     

Wii remote–based low-cost motion capture for automated assembly simulation

This paper describes the development of a Wii remote (Wiimote)–based low-cost motion capture system and demonstrates its application for automated assembly simulation. Multiple Wiimotes are used to form a vision system to perform motion capture in 3D space. A hybrid algorithm for calibrating a multi-camera stereo vision system has been developed based on Zhang’s and Svoboda’s calibration algorithms. This hybrid algorithm has been evaluated and shown accuracy improvement over Svoboda’s algorithm for motion capture with multiple cameras. The captured motion data are used to automatically generate an assembly simulation of objects represented by CAD models in real time. The Wiimote-based motion capture system is practically attractive because it is inexpensive, wireless, and easily portable. Application examples have been developed for a single vision system with two Wiimotes to track the assembly of a microsatellite prototype frame and for an integrated vision system with four Wiimotes to track the assembly of a bookshelf.     

Analysis of vertical eye movements in Parkinson’s disease and its potential for diagnosis

Applied Intelligence - It is well known that eye movements are highly affected by Parkinson’s disease. The majority of studies related to effects of Parkinson’s disease on eye movements...     

Augmenting machine learning for Amharic speech recognition: a paradigm of patient’s lips motion detection

Multimedia Tools and Applications - The method of automatic lip motion recognition is an essential input for visual speech detection. It is a technological approach to demystify people who are hard...     

Automatic generation of temporal planning domains for e-learning problems

AI Planning & Scheduling techniques are being widely used to adapt learning paths to the special features and needs of students both in distance learning and lifelong learning environments. However, instructors strongly rely on Planning & Scheduling experts to encode and review the domains for the planner/scheduler to work. This paper presents an approach to automatically extract a fully operational HTN planning domain and problem from a learning objects repository without requiring the intervention of any planning expert, and thus enabling an easier adoption of this technology in practice. The results of a real experiment with a small group of students within an e-Learning private company in Spain are also shown.     

Automatic generation of fast algorithms for matrix–vector multiplication

This paper describes the methods for finding fast algorithms for computing matrix–vector products including the procedures based on the block-structured matrices. The proposed methods involve an analysis of the structural properties of matrices. The presented approaches are based on the well-known optimization techniques: the simulated annealing and the hill-climbing algorithm along with its several extensions. The main idea of the proposed methods consists in finding a decomposition of the original matrix into a sparse matrix and a matrix corresponding to an appropriate block-structured pattern. The main criterion for optimizing is a reduction of the computational cost. The methods presented in this paper can be successfully implemented in many digital signal processing tasks.     

Approach for automatic font outline generation of NüShu

针对点阵字形存储量大、缩放字形质量难以保证的缺点, 对将女书点阵字形自动转换成曲线轮廓字形的方法进行了研究。首先提取女书轮廓数据; 然后提出了一种基于最大误差值的特征点提取方法; 最后用直线和二次Bezier曲线拟合字形轮廓段, 存储曲线轮廓数据, 从而得到用曲线描述的女书字形。实验结果表明, 该方法计算简单, 大大减少了存储空间, 拟合出来的曲线和原字形轮廓一致, 同时也消除了因手写而造成的毛刺现象, 为在计算机中处理女书奠定了基础。     

Computer generation of sensitivity functions for sampled-data control systems†

Methods have been presented previously (Suryanarayanan and Soudack 1970) for the generation of sensitivity functions for general non-linear sampled-data systems. In this paper, it is shown that economy of simulator components (for hybrid computer generation) or of computational time (for digital computer generation) is achieved for simultaneously generating a number of sensitivity functions in a class of linear sampled-data control systems. Extensive use of signal flow graph algebra is made for this purpose and comprehensive examples are presented.     

A methodology for the generation of planar models for multibody chain drives

To overcome the difficulty on building manually complex models of chain drives, this work proposes a comprehensive methodology to build multibody models of any general chain drive automatically from a minimal set of data. The proposed procedure also evaluates the initial positions and velocities of all components of the drive that are consistent with the kinematic joints or with the contact pairs used in the model. In this methodology, all links and sprockets are represented by rigid bodies connected to each other either by ideal or by clearance revolute joints. The clearance revolute joint contact is further extended to handle the contact between the chain rollers and the sprocket teeth exact profiles. A suitable cylindrical continuous contact law is applied to describe the interaction on all contact pairs. One of the complexities of the computational study of roller chain drives is the large number of bodies in the system and the dynamics of the successive engagement and disengagement of the rollers with the sprockets. Each time a roller engages or disengages with a sprocket tooth, the number of rigid bodies in contact changes. The search for the contact pairs is recognized as one of the most time consuming task in contact analysis. This work proposes a procedure to specify the contact pairs and their update during the dynamic analysis optimizing the computational efficiency of the contact search. The methodologies adopted result in a general computer program that is applied and demonstrated in a generic chain drive that can be used in industrial machines, vehicle engines or any other type of mechanical system.     

Analysis of multiple types of voice recordings in cepstral domain using MFCC for discriminating between patients with Parkinson’s disease and healthy people

In this study, we wanted to discriminate between two groups of people. The database used in this study contains 20 patients with Parkinson’s disease (PD) and 20 healthy people. Three types of sustained vowels (/a/, /o/ and /u/) were recorded from each participant and then the analyses were done on these voice samples. The technique used in this study is to extract voiceprint from each voice samples by using mel frequency cepstral coefficients (MFCCs). The extracted MFCC were compressed by calculating their average value in order to extract the voiceprint from each voice recording. Subsequently, a classification method was performed using leave one subject out (LOSO) validation scheme along with support vector machines (SVMs). We also used an independent test to validate our results by using another database which contains 28 PD patients. Based on the research result, the best obtained classification accuracy using LOSO on the first dataset was 82.50 % using MLP kernel of SVM on sustained vowel /u/. And the maximum classification accuracy using the independent test was 100 % using sustained vowel /a/ with polynomial kernel of the SVM and with MLP kernel of the SVM. This result was also achieved using sustained vowel /o/ with polynomial kernel of the SVM.     

Comparison of templates for homology model of ρ1 GABAC receptors: More insights to the orthosteric binding site’s structure and functionality

Five sets of ρ1 GABA_C homology models were generated based on X-ray crystal structures of the acetylcholine binding protein (AChBP), the ion channel from Caenorhabditis elegans (GLIC), the ion channel from Erwinia chrysanthemi (ELIC), the homomeric GABA_A β₃ ion channel, and the homomeric α-subunit of glutamate-gated homopentameric chloride channel (GluCl). The GluCl based model was found to the represent the structure of ρ1 GABA_C receptors. The GABA pose docked in the selected best model was confirmed by QM-polarized ligand docking and induced fit docking protocol, and used to study molecular interactions in the ρ1 GABA binding site. The potential interactions of identified residues are discussed. This study identified several residues with potential ligand interactions located on loops F and G with their side chain oriented toward the binding site such as Ser215 and Gln83. The partial agonists muscimol and imidazole-4-acetic acid (I4AA) were docked into the binding site of the most reliable ‘GABA bound’ homology model. The potency and efficacy of these partial agonists in activating recombinant ρ1 receptors were correlated with their docking results. The model predicts that muscimol resembles GABA in the docking pose with similar interactions. However, I4AA has a very different docking pose to GABA and was predicted by the model to form π–π stacking with aromatic residues in the orthosteric binding site. A set of TPMPA bound ρ1 homology models based on the GluClα ‘apo state’ template was built in order to study a competitive antagonist in the ρ1 orthosteric binding site. The results demonstrated the ability of our model to explain most experimental findings and predict potential roles of residues within the orthosteric binding site.     

Random generation of industrial pipelines’ data using Markov chain model

Random generation of data sets is a vital step in simulation modeling. It involves in generating the variation associated with the real system behavior. In the industrial fabrication of construction components, unique products such as pipelines are produced. The fabrication processes are dependent on pipelines features, and complexity; randomly generating pipelines structure is imperative in the simulation of such processes. This paper investigates the nature of industrial pipelines and proposes a Markov chain model to randomly generate pipelines data structure. The performance of Markov chain model was tested against real pipelines through a three-stage validation process. The validation process includes (1) a validation based on the number of components and the pipelines components correlation analysis, (2) clustering-based model validation, and (3) model validation using similarity distances between pipelines feature vectors. The Markov chain model was found to generate a reasonable pipelines data structure when compared with real pipelines. It was found that 89% of the generated pipelines share similar properties equivalent to 0.88 (a scale from 0 (not identical) to 1 (identical)) to 85.5% of the original pipelines.     

A Virtual World Grammar for automatic generation of virtual worlds

Hybrid systems such as those that combine 3D virtual worlds and organization based multiagent systems add new visual and communication features for multiuser applications. The design of such hybrid and dynamic systems is a challenging task. In this paper, we propose a system that can automatically generate a 3D virtual world (VW) from an organization based multiagent system (MAS) specification that establishes the activities participants can engage on. Both shape grammar and virtual world paradigms inspired us to propose a Virtual World Grammar (VWG) to support the generation process of a virtual world design. A VWG includes semantic information about both MAS specification and shape grammar elements. This information, along with heuristics and validations, guides the VW generation producing functional designs. To support the definition and execution of a Virtual World Grammar, we have developed a so named Virtual World Builder Toolkit (VWBT). We illustrate this process by generating a 3D visualization of a virtual institution from its specification.     

Development of a muscle suit for the upper body—realization of abduction motion

A 'muscle suit' that will provide muscular support for the paralyzed or those otherwise unable to move unaided is being developed. The muscle suit is a garment without a metal frame that uses McKibben actuators driven by compressed air to produce motion. Because the actuators are sewn into the garment, no metal frame is needed, making the muscle suit very light and cheap. These features are completely different from conventional methods for supporting humans. In this paper, the basic concept and advantages of the muscle suit are first described. In order to verify the feasibility of the basic concept, a prototype system is mounted on a life-size doll. This allows for the limitations of the original design to be identified. Next, an armor-type muscle suit is proposed in order to overcome some of the prototype's limitations. A full-range abduction motion, which is determined to be the most difficult upper body motion, is realized through geometric analysis and experimentation. In the future, the remaining arm motions will be investigated and implemented.     

New technique of obtaining visually perceived positions of 3-D images using movements of users’ bodies

Three-dimensional (3-D) images are perceived as images that float in front of the screens of 3-D displays. Users should be able to interact with these images instantaneously and accurately in applications where their bodies actually seen by them interact with the images. However, conventional techniques using just binocular disparity are too slow and inaccurate. Therefore, we propose a new technique where the visually perceived positions of images are obtained from the body movements of users. The feasibility of this technique was evaluated in an experiment using the positions obtained from users as they reached out to touch the images. These positions were closer to the visually perceived positions of the images than those calculated from binocular disparity. These findings demonstrate the feasibility of the proposed technique for 3-D interactive applications.     

A comparison of tools for strategic simulation and scenario generation with special emphasis on ‘soft factors’

This paper describes a comparison of different tools for strategic simulation and scenario generation. Techniques and tools, namely GAMMA, a causal network editor, a connectance modeller allowing linear analysis and CRIMP, a tool based on dynamic cross-impact modelling and simulation, are presented and applied to a sample company specialised in technological breakthroughs. The results of tools are compared to identify strengths and weaknesses of these approaches.     

An efficient implementation of Bailey and Borwein’s algorithm for parallel random number generation on graphics processing units

Pseudorandom number generators are required for many computational tasks, such as stochastic modelling and simulation. This paper investigates the serial and parallel implementation of a Linear Congruential Generator for Graphics Processing Units (GPU) based on the binary representation of the normal number $\alpha _{2,3}$ . We adapted two methods of modular reduction which allowed us to perform most operations in 64-bit integer arithmetic, improving on the original implementation based on 106-bit double-double operations, which resulted in four-fold increase in efficiency. We found that our implementation is faster than existing methods in literature, and our generation rate is close to the limiting rate imposed by the efficiency of writing to a GPU’s global memory.     

Exact output rate of Peresʼs algorithm for random number generation

An exact computation of the output rate of Peres?s algorithm is reported. The algorithm, recursively defined, converts independent flips of a biased coin into unbiased coin flips at rates that approach the information-theoretic upper bound, as the input size and the recursion depth tend to infinity. However, only the limiting rate with respect to the input size is known for each recursion depth. We compute the exact output rate for each fixed-length input and compare it with another asymptotically optimal method by Elias.