695 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
Control design of uncertain quantum systems with fuzzy estimators
published_or_final_versio
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
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
Suppressing nano-scale stick-slip motion by feedback
When a micro cantilever with a nano-scale tip is manipulated on a substrate
with atomic-scale roughness, the periodic lateral frictional force and
stochastic fluctuations may induce stick-slip motion of the cantilever tip,
which greatly decreases the precision of the nano manipulation. This unwanted
motion cannot be reduced by open-loop control especially when there exist
parameter uncertainties in the system model, and thus needs to introduce
feedback control. However, real-time feedback cannot be realized by the
existing virtual reality virtual feedback techniques based on the position
sensing capacity of the atomic force microscopy (AFM). To solve this problem,
we propose a new method to design real-time feedback control based on the force
sensing approach to compensate for the disturbances and thus reduce the
stick-slip motion of the cantilever tip. Theoretical analysis and numerical
simulations show that the controlled motion of the cantilever tip tracks the
desired trajectory with much higher precision. Further investigation shows that
our proposal is robust under various parameter uncertainties. Our study opens
up new perspectives of real-time nano manipulation.Comment: 8 pages, 10 figure
Cyberbullying Detection on Social Network Services
Social networks such as Facebook or Twitter promote the communication between people but they also lead to some excessive uses on the Internet such as cyberbullying for malicious users. In addition, the accessibility of the social network also allows cyberbullying to occur at anytime and evoke more harm from other users’ dissemination. This study collects cyberbullying cases in Twitter and attempts to establish an auto-detection model of cyberbullying tweets base on the text, readability, sentiment score, and other user information to predict the tweets with harassment and ridicule cyberbullying tweets. The novelty of this study is using the readability analysis that has not been considered in past studies to reflect the author\u27s education level, age, and social status. Three data mining techniques, k-nearest neighbors, support vector machine, and decision tree are used in this study to detect the cyberbullying tweets and select the best performance model for cyberbullying prediction
The RNA binding protein Cwc2 interacts directly with the U6 snRNA to link the nineteen complex to the spliceosome during pre-mRNA splicing
Intron removal during pre-messenger RNA (pre-mRNA) splicing involves arrangement of snRNAs into conformations that promote the two catalytic steps. The Prp19 complex [nineteen complex (NTC)] can specify U5 and U6 snRNA interactions with pre-mRNA during spliceosome activation. A candidate for linking the NTC to the snRNAs is the NTC protein Cwc2, which contains motifs known to bind RNA, a zinc finger and RNA recognition motif (RRM). In yeast cells mutation of either the zinc finger or RRM destabilize Cwc2 and are lethal. Yeast cells depleted of Cwc2 accumulate pre-mRNA and display reduced levels of U1, U4, U5 and U6 snRNAs. Cwc2 depletion also reduces U4/U6 snRNA complex levels, as found with depletion of other NTC proteins, but without increase in free U4. Purified Cwc2 displays general RNA binding properties and can bind both snRNAs and pre-mRNA in vitro. A Cwc2 RRM fragment alone can bind RNA but with reduced efficiency. Under splicing conditions Cwc2 can associate with U2, U5 and U6 snRNAs, but can only be crosslinked directly to the U6 snRNA. Cwc2 associates with U6 both before and after the first step of splicing. We propose that Cwc2 links the NTC to the spliceosome during pre-mRNA splicing through the U6 snRNA
- …