10 research outputs found
Terminal sliding mode control strategy design for second-order nonlinear system
This study mainly focuses on the terminal sliding mode control (TSMC) strategy design, including an adaptive terminal sliding mode control (ATSMC) and an exact-estimator-based terminal sliding mode control (ETSMC) for second-order nonlinear dynamical systems. In the ATSMC system, an adaptive bound estimation for the lump uncertainty is proposed to ensure the system stability. On the other hand, an exact estimator is designed for exact estimating system uncertainties to solve the trouble of chattering phenomena caused by a sign function in ATSMC law in despite of the utilization of a fixed value or an adaptive tuning algorithm for the lumped uncertainty bound. The effectiveness of the proposed control schemes can be verified in numerical simulations.<br /
Towards Assumption-free Bias Mitigation
Despite the impressive prediction ability, machine learning models show
discrimination towards certain demographics and suffer from unfair prediction
behaviors. To alleviate the discrimination, extensive studies focus on
eliminating the unequal distribution of sensitive attributes via multiple
approaches. However, due to privacy concerns, sensitive attributes are often
either unavailable or missing in real-world scenarios. Therefore, several
existing works alleviate the bias without sensitive attributes. Those studies
face challenges, either in inaccurate predictions of sensitive attributes or
the need to mitigate unequal distribution of manually defined non-sensitive
attributes related to bias. The latter requires strong assumptions about the
correlation between sensitive and non-sensitive attributes. As data
distribution and task goals vary, the strong assumption on non-sensitive
attributes may not be valid and require domain expertise. In this work, we
propose an assumption-free framework to detect the related attributes
automatically by modeling feature interaction for bias mitigation. The proposed
framework aims to mitigate the unfair impact of identified biased feature
interactions. Experimental results on four real-world datasets demonstrate that
our proposed framework can significantly alleviate unfair prediction behaviors
by considering biased feature interactions
DiscoverPath: A Knowledge Refinement and Retrieval System for Interdisciplinarity on Biomedical Research
The exponential growth in scholarly publications necessitates advanced tools
for efficient article retrieval, especially in interdisciplinary fields where
diverse terminologies are used to describe similar research. Traditional
keyword-based search engines often fall short in assisting users who may not be
familiar with specific terminologies. To address this, we present a knowledge
graph-based paper search engine for biomedical research to enhance the user
experience in discovering relevant queries and articles. The system, dubbed
DiscoverPath, employs Named Entity Recognition (NER) and part-of-speech (POS)
tagging to extract terminologies and relationships from article abstracts to
create a KG. To reduce information overload, DiscoverPath presents users with a
focused subgraph containing the queried entity and its neighboring nodes and
incorporates a query recommendation system, enabling users to iteratively
refine their queries. The system is equipped with an accessible Graphical User
Interface that provides an intuitive visualization of the KG, query
recommendations, and detailed article information, enabling efficient article
retrieval, thus fostering interdisciplinary knowledge exploration. DiscoverPath
is open-sourced at https://github.com/ynchuang/DiscoverPath
Sintering Temperature-Dependence on Radiopacity of Bi(2âx) ZrxO(3+x/2) Powders Prepared by Sol-Gel Process
Bismuth oxide (Bi2O3) is an effective additive used to enhance radiography resolution for dental materials. However, there are potential concerns regarding its biocompatibility and connection to tissue discoloration. In the present study, we modified the radiopacity properties of Bi2O3 with zirconium oxide (ZrO2) using a sol-gel process and investigated the composition, as well as the effects of heat treatment temperature using Thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The harvested Bi2−xZrxO3+x/2 particles showed that the dominant phase transferred from α-Bi2O3 to β-Bi7.38Zr0.62O12.31 after a heat treatment of over 750 °C for 2 h. As the x values of Bi2−xZrxO3+x/2 increased from 0.2 to 1.0, more zirconium oxide precipitated onto the particle surface, thus enhancing the surface roughness of particles. For sol-gel Bi1.8Zr0.2O3.1 powders (x = 0.2), the radiopacity values became 4.90 ± 0.23 and 5.83 ± 0.22 mmAl after a heat treatment of 500 °C and 750 °C, respectively
Pediatric renal transplantation: Results and prognostic factors
As renal transplantation may increase survival rates and improve quality of life for children with end-stage renal disease, we investigated the long-term outcomes and prognostic factors of pediatric renal transplantation. A retrospective study was conducted to review 25 pediatric renal transplantations, either from live or deceased donors, in our hospital from 1995 to 2008. The cumulative graft survival rate was calculated using the Kaplan-Meier method. Log rank tests were employed to identify categorical prognostic factors for graft survival of the pediatric renal transplantations, and Cox regression analysis for numeric factors. The mean age of our study subjects was 11.63 ± 3.76 years, and the mean follow-up period was 49.24 ± 33.72 months. The 12-month and 36-month graft survival rates were 92% and 82.14%, respectively. The rejection-free survival rates were 88% and 72.88% in the first and third years, respectively. All of the patients were alive during the follow-up period. Acute rejection (p = 0.0175) and male sex (p = 0.0384) were found to be significant factors for graft survival. For pediatric patients, we found that renal transplantation is now a safe and effective surgical procedure for children with end-stage renal disease. Acute rejection and male gender were identified as prognostic factors for poor graft survival
Pediatric renal transplantation: Results and prognostic factors
Background/Objective: As renal transplantation may increase survival rates and improve quality of life for children with end-stage renal disease, we investigated the long-term outcomes and prognostic factors of pediatric renal transplantation.
Methods: A retrospective study was conducted to review 25 pediatric renal transplantations, either from live or deceased donors, in our hospital from 1995 to 2008. The cumulative graft survival rate was calculated using the Kaplan-Meier method. Log rank tests were employed to identify categorical prognostic factors for graft survival of the pediatric renal transplantations, and Cox regression analysis for numeric factors.
Results: The mean age of our study subjects was 11.63 ± 3.76 years, and the mean follow-up period was 49.24 ± 33.72 months. The 12-month and 36-month graft survival rates were 92% and 82.14%, respectively. The rejection-free survival rates were 88% and 72.88% in the first and third years, respectively. All of the patients were alive during the follow-up period. Acute rejection (p = 0.0175) and male sex (p = 0.0384) were found to be significant factors for graft survival.
Conclusion: For pediatric patients, we found that renal transplantation is now a safe and effective surgical procedure for children with end-stage renal disease. Acute rejection and male gender were identified as prognostic factors for poor graft survival