1,359 research outputs found
Investigating Virus Clearance via pH Inactivation During Biomanufacturing
In the processing of biopharmaceuticals, viral clearance and viral safety are important for the development of monoclonal antibodies. Murine xenotropic leukemia virus (XMuLV) is one of the retroviruses, recommended by Food and Drug Administration (FDA) as a model virus for viral clearance via inactivation from therapeutics derived from Chinese hamster ovary cells (CHO). A robust and effective method was investigated to clear or inactivate endogenous viruses by low pH inactivation. The effects of different conductivity and inactivated time on XMuLV clearance was determined. Acetate buffer was prepared with different conductivity, and 2% XMuLV was spiked into acetate buffer. XMuLV virus particles could be effectively inactivated in acetate buffer at pH 3.6. According to TICD50 assay, the inactivation time of around 60 minutes was enough to clear all the viruses with more than 4 logs reduction value (LRV). Also, 50 mM acetate buffer has the most rapid inactivation process. TICD50 assays were able to determine the XMuLV virus titer within 95% confidence level, by using 8 replicates and 10-fold series dilution factor
Development of Collaborative SLAM Algorithm for Team of Robots
Simultaneous Localization and Mapping (SLAM) is a fundamental problem for building truly automatic robots. Varieties of methods and algorithms have been generated, and applied into mobile robots during the last thirty years. However, each algorithm has its strength and weakness. This thesis studies the most recent published techniques in the field of mobile robot SLAM. Specifically, it focuses on investigating robot path and landmark position estimating errors made by different methods. The Hybrid method, which uses FastSLAM method as front-end and uses EKF-SLAM method as back-end, combines both methods advantages, producing smaller errors on estimating robot pose. The Hybrid method solves the single robot SLAM problems by summing the weighted mean values of each particle in FastSLAM. The contributions of this thesis is it presents an alternate mapping algorithm that extends this single-robot Hybrid SLAM algorithm to a multi-robot SLAM algorithm. In this algorithm, each robot draws map of the environment separately, and robots could transfer their mapping information into a central computer. The central computer could merge the landmark positions from different robots. At last, a revised landmark position as well as its covariance will be calculated. Landmark positions are fused together according to two robots feature information by using Kalman Filters
A Situation of Economic Management in NTU Cooperative Fuzzy Games
In economic management, we often use some (divisible) private resources to cooperative. Fuzzy coalitions always be used to describe this situation in cooperative fuzzy games. In this paper, we proposed two new solution concepts in NTU cooperative fuzzy games, and discussed their properties
Hybrid Fault-Tolerant Consensus in Asynchronous and Wireless Embedded Systems
Byzantine fault-tolerant (BFT) consensus in an asynchronous system can only tolerate up to floor[(n-1)/3] faulty processes in a group of n processes. This is quite a strict limit in certain application scenarios, for example a group consisting of only 3 processes. In order to break through this limit, we can leverage a hybrid fault model, in which a subset of the system is enhanced and cannot be arbitrarily faulty except for crashing. Based on this model, we propose a randomized binary consensus algorithm that executes in complete asynchrony, rather than in partial synchrony required by deterministic algorithms. It can tolerate up to floor[(n-1)/2] Byzantine faulty processes as long as the trusted subsystem in each process is not compromised, and terminates with a probability of one. The algorithm is resilient against a strong adversary, i. e. the adversary is able to inspect the state of the whole system, manipulate the delay of every message and process, and then adjust its faulty behaviour during execution.
From a practical point of view, the algorithm is lightweight and has little dependency on lower level protocols or communication primitives. We evaluate the algorithm and the results show that it performs promisingly in a testbed consisting of up to 10 embedded devices connected via an ad hoc wireless network
A Mathematical Model for Thermosensitive Liposomal Delivery of Doxorubicin to Solid Tumour
Peer reviewedPublisher PD
Joint Radio Frequency Fingerprints Identification via Multi-antenna Receiver
In Internet of Things (IoT), radio frequency fingerprints (RFF) technology
has been widely used for passive security authentication to identify the
special emitter. However, few works took advantage of independent oscillator
distortions at the receiver side, and no work has yet considered filtering
receiver distortions. In this paper, we investigate the RFF identification
(RFFI) involving unknown receiver distortions, where the phase noise caused by
each antenna oscillator is independent. Three RFF schemes are proposed
according to the number of receiving antennas. When the number is small, the
Mutual Information Weighting Scheme (MIWS) is developed by calculating the
weighted voting of RFFI result at each antenna; when the number is moderate,
the Distortions Filtering Scheme (DFS) is developed by filtering out the
channel noise and receiver distortions; when the number is large enough, the
Group-Distortions Filtering and Weighting Scheme (GDFWS) is developed, which
integrates the advantages of MIWS and DFS. Furthermore, the ability of DFS to
filter out the channel noise and receiver distortions is theoretically analyzed
at a specific confidence level. Experiments are provided when both channel
noise and receiver distortions exist, which verify the effectiveness and
robustness of the proposed schemes
On the Analysis of the Illumina 450k Array Data: Probes Ambiguously Mapped to the Human Genome
We pointed out that a substantial number of CpG probes on the Illumina 450K
array could be mapped to multiple loci across the human genome. These CpGs need
to be considered when interpreting results using this platform
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