865 research outputs found
Nonlinear feedback control of multiple robot arms
Multiple coordinated robot arms are modeled by considering the arms: (1) as closed kinematic chains, and (2) as a force constrained mechanical system working on the same object simultaneously. In both formulations a new dynamic control method is discussed. It is based on a feedback linearization and simultaneous output decoupling technique. Applying a nonlinear feedback and a nonlinear coordinate transformation, the complicated model of the multiple robot arms in either formulation is converted into a linear and output decoupled system. The linear system control theory and optimal control theory are used to design robust controllers in the task space. The first formulation has the advantage of automatically handling the coordination and load distribution among the robot arms. In the second formulation, by choosing a general output equation, researchers can superimpose the position and velocity error feedback with the force-torque error feedback in the task space simultaneously
ERP System Solutions for Small Companies: Readiness & Selection
Over the past decade almost all of major businesses in the US have implemented Enterprise Resource Planning (ERP) systems to run daily business operations. However, a complex ERP system, if not implemented properly, can easily disrupt, or sometimes cripple, the flow of the manufacturing and other operations. While large organizations are in a unique position to implement a good RP system, most small companies cannot afford the acquisition and implementation cost of a big name ERP system. Therefore, smaller organizations rely on vendors with affordable, but not necessarily proven, ERP systems. To help small businesses avoid implementation problems and system glitches after ERP implementation, two proactive initiaves are recommended. ERP readiness and ERP selection. This article organizes a checklist for each initiative so that small companies are better prepared to overcome implementation challenges and their expectations are more aligned with the norm of an ERP implementation
Phaseguide assisted liquid lamination for magnetic particle-based assays
We have developed a magnetic particle-based assay platform in which functionalised magnetic particles are transferred sequentially through laminated volumes of reagents and washing buffers. Lamination of aqueous liquids is achieved via the use of phaseguide technology; microstructures that control the advancing air–liquid interface of solutions as they enter a microfluidic chamber. This allows manual filling of the device, eliminating the need for external pumping systems, and preparation of the system requires only a few minutes. Here, we apply the platform to two on-chip strategies: (i) a one-step streptavidin–biotin binding assay, and (ii) a two-step C-reactive protein immunoassay. With these, we demonstrate how condensing multiple reaction and washing processes into a single step significantly reduces procedural times, with both assay procedures requiring less than 8 seconds
Positron detection in silica monoliths for miniaturised quality control of PET radiotracers
We demonstrate the use of the miniaturised Medipix positron sensor for detection of the clinical PET radiotracer, [⁶⁸Ga]gallium-citrate, on a silica-based monolith, towards microfluidic quality control. The system achieved a far superior signal-to-noise ratio compared to conventional sodium iodide-based radio-HPLC detection and allowed real-time visualisation of positrons in the monolith
Time-delay control of a magnetic levitated linear positioning system
In this paper, a high accuracy linear positioning system with a linear force actuator and magnetic levitation is proposed. By locating a permanently magnetized rod inside a current-carrying solenoid, the axial force is achieved by the boundary effect of magnet poles and utilized to power the linear motion, while the force for levitation is governed by Ampere's Law supplied with the same solenoid. With the levitation in a radial direction, there is hardly any friction between the rod and the solenoid. The high speed motion can hence be achieved. Besides, the axial force acting on the rod is a smooth function of rod position, so the system can provide nanometer resolution linear positioning to the molecule size. Since the force-position relation is highly nonlinear, and the mathematical model is derived according to some assumptions, such as the equivalent solenoid of the permanently magnetized rod, so there exists unknown dynamics in practical application. Thus 'robustness' is an important issue in controller design. Meanwhile the load effect reacts directly on the servo system without transmission elements, so the capability of 'disturbance rejection; is also required. With the above consideration, a time-delay control scheme is chosen and applied. By comparing the input-output relation and the mathematical model, the time-delay controller calculates an estimation of unmodeled dynamics and disturbances and then composes the desired compensation into the system. Effectiveness of the linear positioning system and control scheme are illustrated with simulation results
Joint Modeling and Registration of Cell Populations in Cohorts of High-Dimensional Flow Cytometric Data
In systems biomedicine, an experimenter encounters different potential
sources of variation in data such as individual samples, multiple experimental
conditions, and multi-variable network-level responses. In multiparametric
cytometry, which is often used for analyzing patient samples, such issues are
critical. While computational methods can identify cell populations in
individual samples, without the ability to automatically match them across
samples, it is difficult to compare and characterize the populations in typical
experiments, such as those responding to various stimulations or distinctive of
particular patients or time-points, especially when there are many samples.
Joint Clustering and Matching (JCM) is a multi-level framework for simultaneous
modeling and registration of populations across a cohort. JCM models every
population with a robust multivariate probability distribution. Simultaneously,
JCM fits a random-effects model to construct an overall batch template -- used
for registering populations across samples, and classifying new samples. By
tackling systems-level variation, JCM supports practical biomedical
applications involving large cohorts
HOTEL RECOMMENDATION SYSTEM BASED ON REVIEW AND CONTEXT INFORMATION: A COLLABORATIVE FILTERING APPRO
In most organizations, knowledge sharing is often lacking when it comes to business systems success. This paper investigates factors affecting business systems success in Saudi organisations. Data were collected from private organisations in Saudi Arabia and Partial Least Square approach has been applied to analyse the data. The results show that organisational culture influence knowledge sharing towards business systems success. In addition, both intrinsic motivation and perceived usefulness has positive influence on business system success. This indicates that business system success is built upon the concept of knowledge sharing and user motivation
Electronic Health Records (EHR) Implementation and Post Implementation Challenges
The US Healthcare Industry lags behind other industries in its use of technologies for process improvement and improvement in quality of services for its patients. Globally, United States is significantly behind some European and Australian countries in implementation of EHR. While the federal government is now mandating this change and also offering incentive programs, healthcare providers remain slow to comply because of challenges they face regarding EHR implementation. This paper discusses EHR architecture, presents implementation challenges, provides a case study and offers future research ideas. The information provided in this research could be beneficial for successful EHR implementation
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