47 research outputs found
On the composition conjecture for a class of rigid systems
In this paper, we prove that for a class of rigid systems the Composition Conjecture is correct. We show that the Moments Condition is the sufficient and necessary conditions for these rigid systems to have a center at origin point. By the obtained conclusions we can derive all the focal values of these higher order polynomial differential systems and their expressions are more succinct and beautiful
On the composition conjecture for a class of rigid systems
In this paper, we prove that for a class of rigid systems the Composition Conjecture is correct. We show that the Moments Condition is the sufficient and necessary conditions for these rigid systems to have a center at origin point. By the obtained conclusions we can derive all the focal values of these higher order polynomial differential systems and their expressions are more succinct and beautiful
Document Clustering in Antimicrobial Peptides Research
Antimicrobial peptides are small peptides encoded by genes. The research area of antimicrobial peptides has attracted intense attention in recent years because âtheir potential use in the cure of infectious diseases caused by pathogens that have become counteractive to traditional antibioticsâ (Boman 1994). There exist huge amount of antimicrobial peptides research articles and this number is continuously increasing. Although some biomedical databases, such as PubMed, have been well established, they provide only query-based information retrieval and end-users need to manually find out relevant information from thousands of retrieved articles. The objective of this paper is to apply one of the text mining techniques, document clustering, which groups similar documents into clusters, to text documents collected from PubMed using keyword âantimicrobial peptidesâ. The results of our work can help researchers to discover meaningful groups of antimicrobial peptides articles in an efficient manner
Using Non-Additive Measure for Optimization-Based Nonlinear Classification
Over the past few decades, numerous optimization-based methods have been proposed for solving the classification problem in data mining. Classic optimization-based methods do not consider attribute interactions toward classification. Thus, a novel learning machine is needed to provide a better understanding on the nature of classification when the interaction among contributions from various attributes cannot be ignored. The interactions can be described by a non-additive measure while the Choquet integral can serve as the mathematical tool to aggregate the values of attributes and the corresponding values of a non-additive measure. As a main part of this research, a new nonlinear classification method with non-additive measures is proposed. Experimental results show that applying non-additive measures on the classic optimization-based models improves the classification robustness and accuracy compared with some popular classification methods. In addition, motivated by well-known Support Vector Machine approach, we transform the primal optimization-based nonlinear classification model with the signed non-additive measure into its dual form by applying Lagrangian optimization theory and Wolfes dual programming theory. As a result, 2 â 1 parameters of the signed non-additive measure can now be approximated with m (number of records) Lagrangian multipliers by applying necessary conditions of the primal classification problem to be optimal. This method of parameter approximation is a breakthrough for solving a non-additive measure practically when there are a relatively small number of training cases available (). Furthermore, the kernel-based learning method engages the nonlinear classifiers to achieve better classification accuracy. The research produces practically deliverable nonlinear models with the non-additive measure for classification problem in data mining when interactions among attributes are considered
Theoretical Simulation and Optimization on Material Parameters of Thin Film Bulk Acoustic Resonator
Candiduria in hospitalized patients: an investigation with the Sysmex UF-1000i urine analyzer
Background Candiduria is common in hospitalized patients. Its management is limited because of inadequate understanding. Previous epidemiological studies based on culture assay have been limited to small study populations. Therefore, data collected by automated systems from a large target population are necessary for more comprehensive understanding of candiduria in hospitalized patients. Methods To determine the performance of the Sysmex UF-1000i in detecting candiduria, a cross-sectional study was designed and conducted. A total of 203 yeast-like cell (YLC)-positive and 127 negative samples were randomly chosen and subjected to microbiologic analysis. The receiver operating characteristic curve (ROC) was used to evaluate the ability of YLC counts as measured by the Sysmex UF1000i to predict candiduria. Urinalysis data from 31,648 hospitalized patients were retrospectively investigated, and statistical analysis was applied to the data collected. Results Using a cutoff value of 84.6 YLCs/”L, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the yeast like cell (YLC) counts to predict candiduria were 61.7%, 84.1%, 88.6% and 66.3%, respectively. C. glabrata (33.6%) and C. tropicalis (31.4%) were more prevalent than C. albicans (24.3%) in the present study. Of the investigated hospitalized patients, 509 (1.61%) were considered candiduria-positive. Age, gender and basic condition were associated with candiduria in hospitalized patients. In the ICU setting, urinary catheterization appeared to be the only independent risk factor contributing to candiduria according to our investigation. Although antibiotic therapy has been reported to be a very important risk factor, we could not confirm its significance in ICU candiduria patients because of excessive antibiotic usage in our hospital. Conclusions The YLC measured by Sysmex UF-1000i is a practical and convenient tool for clinical candiduria screening prior to microbiologic culture. Candiduria is common in hospitalized patients, and its incidence varies according to age, gender and the wards where it is isolated. Candiduria had no direct connection with mortality but might be considered a marker of seriously ill patients who need particular attention in the clinic
On the composition conjecture for a class of rigid systems
In this paper, we prove that for a class of rigid systems the Composition Conjecture is correct. We show that the Moments Condition is the sufficient and necessary conditions for these rigid systems to have a center at origin point. By the obtained conclusions we can derive all the focal values of these higher order polynomial differential systems and their expressions are more succinct and beautiful
Phase transitions of a double occupancy lattice gas
This article offers a detailed analysis of interacting particles in the two-dimensional square array, which is a coarse-graining model to study the multiple occupancy lattice gas system. The equilibrium properties with the maximum loading number 2 is obtained in this work. We find the large nearest neighbor interaction leads to the steeper isotherms and the large on-site interaction leads to the plateaus isotherms. The phase transitions are discussed, and the phase diagrams are obtained via the Monte Carlo simulations. By analyzing finite size effect and the hysteresis behavior, the phase boundaries and the tricritical points are located in the phase diagrams. Our results reveal the complex equilibrium phase transitions in the double occupancy lattice gas
Non-equilibrium Phase Transitions in 2D Small-World Networks: Competing Dynamics
This article offers a detailed analysis of the Ising model in 2D small-world networks with competing Glauber and Kawasaki dynamics. The non-equilibrium stationary state phase transitions are obtained in these networks. The phase transitions are discussed, and the phase diagrams are obtained via Monte Carlo simulations and finite-size analyzing. We find that as the addition of links increases the phase transition temperature increases and the transition competing probability of tricritical point decreases. For the competition of the two dynamics, ferromagnetic to anti-ferromagnetic phase transitions and the critical endpoints are found in the small-world networks
Plant diversity increases N removal in constructed wetlands when multiple rather than single N processes are considered
Biodiversity has a close relationship with ecosystem functioning. For most biodiversityâecosystemâfunctioning studies, biodiversity has been linked to a single indicator variable of ecosystem functioning. However, there are generally multiple ecosystem processes contributing to ecosystem functioning and they differ in their dependence on biodiversity. Thus, the relationship between biodiversity and ecosystem functioning can be stronger when multiple rather than single ecosystem processes are considered. Using both massâbalance and stableâisotope approaches, we explored the effects of plant diversity on nitrogen (N) removal sustained by multiple Nâcycling processes in experimental microcosms simulating constructed wetlands, an ecosystem treating wastewater with high N loading. Four species were used to assemble different plant communities, ranging in richness from one to four species. The removal of N, indicated by low levels of total inorganic N concentration (TIN) present in the effluent, was considered as an integrated measure of ecosystem functioning, combining three constituent Nâcycling processes: plant uptake, denitrification, and substrate adsorption. Our results showed that (1) species richness had a positive effect on N removal, in particular, the fourâspecies mixture reduced effluent TIN to a lower level than any monoculture; however, polycultures (twoâ, threeâ, and fourâspecies mixtures) did not outperform the most efficient monoculture when each of the three constituent Nâcycling processes was considered by itself; (2) species identity had significant impacts on single processes. Communities with the species Coix lacrymaâjobi showed the greatest capacity for N uptake and communities with Phragmites australis had the highest denitrification rates; (3) isotope fractionation in the rhizosphere of Coix lacrymaâjobi was primarily due to microbial denitrification while multistep isotope fractionation was detected for Phragmites australis and Acorus calamus (indicating recycling of N), suggesting that species differed in the way they transformed N; (4) the enhanced N removal at high diversity may be due to mutualistic interactions among species belonging to different functional types. Our findings demonstrated that although plant species richness had negligible effects on individual Nâcycling processes, it enhanced the overall ecosystem functioning (N removal) when these processes were considered collectively. Our study thus contributes to improve the treatment efficiency of constructed wetlands through proper vegetation management