2,929 research outputs found

    An RLL code design that maximises channel utilisation

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    Comprehensive (d,k) sequences study is presented, complemented with the design of a new, efficient, Run-Length Limited (RLL) code. The new code belongs to group of constrained coding schemas with a coding rate of R = 2/5 and with the minimum run length between two successive transitions equal to 4. Presented RLL (4, oo) code uses channel capacity highly efficiently, with 98.7% and consequently it achieves a high-density rate of DR = 2.0. It is implying that two bits can be recorded, or transmitted with one transition. Coding techniques based on the presented constraints and the selected coding rate have better efficiency than many other currently used codes for high density optical recording and transmission

    On the performance of sampling-based optimal motion planners

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    Sampling based algorithms provide efficient methods of solving robot motion planning problem. The advantage of these approaches is the ease of their implementation and their computational efficiency. These algorithms are probabilistically complete i.e. they will find a solution if one exists, given a suitable run time. The drawback of sampling based planners is that there is no guarantee of the quality of their solutions. In fact, it was proven that their probability of reaching an optimal solution approaches zero. A breakthrough in sampling planning was the proposal of optimal based sampling planners. Current optimal planners are characterized with asymptotic optimality i.e. they reach an optimal solutions as time approaches infinity. Motivated by the slow convergence of optimal planners, post-processing and heuristic approach have been suggested. Due to the nature of the sampling based planners, their implementation requires tuning and selection of a large number of parameters that are often overlooked. This paper presents the performance study of an optimal planner under different parameters and heuristics. We also propose a modification in the algorithm to improve the convergence rate towards an optimal solution

    Examining the use of B-splines in parking assist systems

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    The main objective of the presented study and simulations conducted was to investigate the prospect of using B-spline curves for the automatic parking, i.e. self-driving, or intelligent vehicles. We consider the problem of parallel parking for a non-holonomic vehicle with a known maximum path curvature. The relationship between the properties of the path and the geometry of corresponding parking spot is revealed. The unique properties of B-splines are exploited to synthesize a path that is smooth and of continuous curvature. The contributions of this project are in the generations of better, smooth continuous paths. This improves passenger comfort during the parallel parking maneuver and allow vehicles to park in tighter spots by increasing the feasible range of the parking manoeuver

    Stark Broadening of in III Lines in Astrophysical and Laboratory Plasma

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    Besides the need of Stark broadening parameters for a number of problems in physics, and plasma technology, in hot star atmospheres the conditions exist where Stark widths are comparable and even larger than the thermal Doppler widths. Using the semiclassical perturbation method we investigated here the influence of collisions with charged particles for In III spectral lines. We determined a number of Stark broadening parameters important for the investigation of plasmas in the atmospheres of A-type stars and white dwarfs. Also, we have compared the obtained results with existing experimental data. The results will be included in the STARK-B database, the Virtual Atomic and Molecular Data Center and the Serbian Virtual Observatory

    Holistic educational development integrated through mechatronics design

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    This paper presents an approach in educational development of resources and programs based on multidisciplinary concept. The development is built around the process of mechatronics program delivery that is currently introduced in tertiary education within RMIT University. Mechatronics is a multidisciplinary engineering area that incorporates mechanical, electrical, electronics, computer and information systems. Students studying Mechatronics Engineering expand their knowledge of various systems and scientific areas and integrate them in a working system. Through work integrated learning, students are encouraged to obtain new knowledge and skills by doing the job, not just learning from the textbooks and attending lectures. Subject material is delivered in variety of ways, started with face-to-face delivery, seminars, tutorials and lab sessions. The key component of this education is project work conducted in small teams. Finally, University conducts surveys after every single subject delivery and the results of the latest survey are presented here. According to the survey, students are extremely satisfied with the new approach that focuses on problem solving, project and exploration work

    Exploring barriers to 'Respondent driven sampling' in sex worker and drug-injecting sex worker populations in Eastern Europe

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    Respondent driven sampling (RDS) has been used in several counties to sample injecting drug users, sex workers (SWs) and men who have sex with men and as a means of collecting behavioural and biological health data. We report on the use of RDS in three separate studies conducted among SWs between 2004 and 2005 in the Russian Federation, Serbia, and Montenegro. Findings suggest that there are limitations associated with the use of RDS in SW populations in these regions. Findings highlight three main factors that merit further investigation as a means of assessing the feasibility and appropriateness of RDS in this high risk population: the network characteristics of SWs; the appropriate level of participant incentives; and lack of service contact. The highly controlled and hidden nature of SW organizations and weak SW social networks in the region can combine to undermine assumptions underpinning the feasibility of RDS approaches and potentially severely limit recruitment. We discuss the implications of these findings for recruitment and the use of monetary and non-monetary incentives in future RDS studies of SW populations in Eastern Europe

    Autonomous robots path planning: An adaptive roadmap approach

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    Developing algorithms that allow robots to independently navigate unknown environments is a widely researched area of robotics. The potential for autonomous mobile robots use, in industrial and military applications, is boundless. Path planning entails computing a collision free path from a robots current position to a desired target. The problem of path planning for these robots remains underdeveloped. Computational complexity, path optimization and robustness are some of the issues that arise. Current algorithms do not generate general solutions for different situations and require user experience and optimization. Classical algorithms are computationally extensive. This reduces the possibility of their use in real time applications. Additionally, classical algorithms do not allow for any control over attributes of the generated path. A new roadmap path planning algorithm is proposed in this paper. This method generates waypoints, through which the robot can avoid obstacles and reach its goal. At the heart of this algorithm is a method to control the distance of the waypoints from obstacles, without increasing its computational complexity. Several simulations were run to illustrate the robustness and adaptability of this approach, compared to the most commonly used path planning methods

    Patient-controlled intravenous morphine analgesia combined with transcranial direct current stimulation for post-thoracotomy pain: A cost-effectiveness study and a feasibility for its future implementation

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    This prospective randomized study aims to evaluate the feasibility and cost-effectiveness of combining transcranial direct current stimulation (tDCS) with patient controlled intravenous morphine analgesia (PCA-IV) as part of multimodal analgesia after thoracotomy. Patients assigned to the active treatment group (a-tDCS

    Assessing ASD in Adolescent Females with Anorexia Nervosa using Clinical and Developmental Measures: a Preliminary Investigation

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    The aim of this study was to use standardised, clinical assessment tools to explore the presence of Autism Spectrum Disorder (ASD) symptoms in a sample of adolescent females with Anorexia Nervosa (AN), receiving either day-patient or inpatient treatment for their eating disorder and to determine whether any such symptoms were present during the early developmental period, a requirement for a diagnosis of ASD. Using a cross-sectional design, 40 females aged between 12 and 18 were recruited from inpatient and day-patient eating disorder services. All participants had a diagnosis of AN and were assessed for symptoms of ASD using the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2). If participants scored at or above clinical cut-off on the ADOS-2, their parents were asked to complete the Developmental, Dimensional and Diagnostic Interview, short version (3Di-sv). Of the 40 participants assessed, 21 scored above cut-off on the ADOS-2. When developmental history was obtained, only four participants scored above cut-off on all sub-scales of the 3Di-sv, thus meeting full research criteria for ASD. This study suggests that 10% of adolescents with AN from inpatient or day-patient settings may have diagnosable ASD, while a further 40% may show symptoms of ASD, which may arise from the ill-state of AN or are not supported by parental report
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